1538-4047 Cancer Biology & Therapy cbt Austin, Tx Landes Bioscience biweekly January/February 2002 - http://dx.doi.org/10.4161/cbt http://www.landesbioscience.com/journals/cbt/ 1538-4047 Humaira Gowher and Albert Jeltsch cbt Mechanism of inhibition of DNA methyltransferases by cytidine analogs in cancer therapy Landes Bioscience 2004-10-15 1062 - 1068 Cancer Biology & Therapy 3-11 Landes Bioscience Hypermethylation of tumor suppressor genes caused by aberrant activity of DNA methyltransferases is an important mechanism that contributes to cancer. The reaction mechanism of DNA methyltransferases, which includes formation of a covalent intermediate between the enzyme and the target base, is the basis of the success of several anti-cancer drugs that are targeted against DNA methylation. These include 5-fluoro-2'-deoxycytidine, 5-aza-2'-deoxycytidine (Decitabine) and 2-H pyrimidinone-1-ß-D(2'-deoxyriboside) (Zebularine). This review provides an insight to how the chemistry of DNA methylation is involved in the performance of these drugs targeted against it. http://dx.doi.org/10.4161/cbt.3.11.1308 http://www.landesbioscience.com/journals/cbt/article/1308/ article Focus on the Liver 1538-4047 James V. Alvarez and David A. Frank cbt Genome-wide analysis of STAT target genes: Elucidating the mechanism of STAT-mediated oncogenesis Landes Bioscience 2004-10-15 1045 - 1050 Cancer Biology & Therapy 3-11 Landes Bioscience Inappropriate activation of transcription factors is a common event in cancer. These transcription factors contribute to a malignant phenotype by regulating genes involved in cellular proliferation, survival, differentiation, angiogenesis, and invasion. An important goal remains identifying the targets of oncogenic transcription factors that execute these changes. STAT proteins are among the best-studied of these transcription factors, and are involved in oncogenesis both in vivo and in vitro. They thus represent an ideal model for understanding how transcription factors cause cancer through coordinated changes in gene expression. Recent studies have employed microarray-based expression analysis to comprehensively identify STAT target genes. Analysis of these targets can provide insight into mechanisms of neoplastic transformation, and may shed light on new strategies for targeted therapy. http://dx.doi.org/10.4161/cbt.3.11.1172 http://www.landesbioscience.com/journals/cbt/article/1172/ article Review 1538-4047 Roya Khosravi-Far cbt Death receptor signals to the mitochondria Landes Bioscience 2004-10-15 1051 - 1057 Cancer Biology & Therapy 3-11 Landes Bioscience Apoptosis is the best-characterized form of programmed cell death (PCD) and is of fundamental importance in tissue homeostasis. In mammalian systems, there are two major pathways that are involved in the initiation of apoptosis: the “extrinsic” death receptor pathway and the “intrinsic” mitochondrial pathway. Although these pathways act independently to initiate the death machinery in some cellular systems, in many cell types, including numerous tumor cells, there is delicate coordination and cross talk between the extrinsic and intrinsic pathways, which leads to the activation of the executioner caspase cascade. Additionally, there appears to be a fine balance between the caspase-mediated arm of death receptor signaling that engages mitochondria and the caspase-independent arm that promotes vacuole proliferation in many cells. Here, we review our current knowledge about the layers of complexity that are posed by the interactions between death receptor-induced pathways and how they influence mitochondria to regulate cellular life and death decisions. http://dx.doi.org/10.4161/cbt.3.11.1173 http://www.landesbioscience.com/journals/cbt/article/1173/ article Review 1538-4047 Jian-Hua Zhang Ming-Xi Wan Bo-Rong Pan and Bing Yu cbt Cytotoxicity of HSVtk and hrTNF-alpha fusion genes with IRES in treatment of gastric cancer Landes Bioscience 2004-10-15 1075 - 1080 Cancer Biology & Therapy 3-11 Landes Bioscience The efficacy of the suicide gene therapy by using the herpes simplex virus thymidine kinase/ganciclovir (HSVtk/GCV) system for the treatment of cancer is limited because of the insufficient gene transfer and the low killing activity. To enhance the antitumor activity, we probed into whether recombinant ritroviral expression vector PLXSN expressing both HSVtk and TNF-? genes could potentiate the destruction of SGC7901. The PL(tk-TNF-?)SN harboring HSVtk and TNF-? genes in sequence was constructed with a bicistronic unit including the internal ribosomal entry site, the recombinant retroviruses were transferred into SGC7901 cells by lipofectamine, and pEGFP and Western blot analysis were used to detect the expression of fusion genes in transfected SGC7901 cells, and then apoptosis of the transfected cells were detected by using the TdT-mediated dUTP nick end labeling, flow cytometric analysis and transmission electron microscopy. In vitro study, the transfected gastric cancer cells were maintained in the GCV-contained medium, to assay the cell killing effect and bystander effect. In vivo experiments, retroviral serum plasmids were transfected into tumor-bearing nude mice, to observe the changes of tumor volumes and survival of the mice. In vitro there was no significant difference of cell survival rate between the three groups. However, in vivo results showed that tk/GCV, tk-TNF-?/GCV and TNF-? could inhibit the tumor growth, and the obvious anti-tumor effect was shown in tk-TNF-?/GCV group, and TNF-? obviously enhanced the anti-tumor effect in vivo. The pathologic examination showed necrosis of the cancer in the treated groups. http://dx.doi.org/10.4161/cbt.3.11.1174 http://www.landesbioscience.com/journals/cbt/article/1174/ article Research Paper 1538-4047 Dengfeng Cao Steven R. Hustinx Guoping Sui P. Bala Norihiro Sato Sean Martin Anirban Maitra Kathleen M. Murphy John L. Cameron Charles J. Yeo Scott E. Kern Michael Goggins Akhilesh Pandey and Ralph H. Hruban cbt Identification of novel highly expressed genes in pancreatic ductal adenocarcinomas through a bioinformatics analysis of expressed sequence tags Landes Bioscience 2004-10-15 1081 - 1089 Cancer Biology & Therapy 3-11 Landes Bioscience In most microarray experiments, a significant fraction of the differentially expressed mRNAs identified correspond to expressed sequence tags (ESTs) and are generally discarded from further analyses. We used careful bioinformatics analyses to characterize those ESTs that were found to be highly overexpressed in a series of pancreatic adenocarcinomas. cDNA was prepared from 60 non-neoplastic samples (normal pancreas [n = 20], normal colon [n = 10], or normal duodenal mucosal [n = 30]) and from 64 pancreatic cancers (resected cancers [n = 50] or cancer cell lines [n = 14]) and hybridized to the complete Affymetrix Human Genome U133 GeneChip® set (arrays U133A and B) for simultaneous analysis of 45,000 fragments corresponding to 33,000 known genes and 6,000 ESTs. The GeneExpress® software system Fold Change Analysis Tool was used and 60 ESTs were identified that were expressed at levels at least 3-fold greater in the pancreatic cancers as compared to normal tissues. Searches against the human genomic sequence and comparative genomic analysis of human and mouse genomes was carried out using basic local alignment search tools (BLAST), BLASTN, and BLASTX, for identifying protein coding genes corresponding to the ESTs. Subsequently, in order to pick the most relevant candidate genes for a more detailed analysis, we looked for domains/motifs in the open reading frames using SMART and Pfam programs. We were able to definitively map 43 of the 60 ESTs to known or novel genes, and 15 of the ESTs could be localized in close proximity to a gene in the human genome although we were unable to establish that the EST was indeed derived from those genes. The differential expression of a subset of genes was confirmed at the protein level by immunohistochemical labeling of tissue microarrays (inhibin b A [INHBA] and CD29) and/or at the transcript level by RT-PCR (INHBA, AKAP12, ELK3, FOXQ1, EIF5A2, and EFNA5). We conclude that bioinformatics tools can be used to characterize differentially overexpressed ESTs, and that some of these ESTs may represent diagnostically and therapeutically useful targets that might be missed using data solely from currently annotated databases. http://dx.doi.org/10.4161/cbt.3.11.1175 http://www.landesbioscience.com/journals/cbt/article/1175/ article Research Paper 1538-4047 Shi-Yong Sun Zhongmei Zhou Ruoxiang Wang Haian Fu and Fadlo R. Khuri cbt The farnesyltransferase inhibitor lonafarnib induces growth arrest or apoptosis of human lung cancer cells without downregulation of Akt Landes Bioscience 2004-10-15 1092 - 1098 Cancer Biology & Therapy 3-11 Landes Bioscience Farnesyltransferase inhibitors (FTIs) have been demonstrated to induce growth arrest or apoptosis independent of Ras mutation. Alternatively, Akt has been proposed as a potential target for the FTI’s actions. This study investigated whether Lonafarnib was effective in inhibiting the growth of human non-small cell lung cancer (NSCLC) cells and elucidated the role of Akt in mediating such growth inhibitory effects. Lonafarnib, at clinical achievable concentration ranges, was effective in inhibiting the growth of 10 NSCLC cell lines, particularly after a prolonged treatment, regardless of Ras mutational status. Lonafarnib arrested cells growth at G1 or G2/M phase in the majority tested cell lines. However it induced apoptosis when cells were cultured in a low serum (0.1%) medium. The majority of NSCLC cell lines expressed undetectable level of phosphorylated Akt (p-Akt). Lonafarnib at up to 10 µM did not decrease either total Akt level or p-Akt level in any of the tested cell lines, even after a 48 h treatment. Unexpectedly, Lonafarnib even increased p-Akt level in one cell line, although it was as sensitive as others to Lonafarnib treatment and underwent G2/M arrest. Bovine serum albumin completely rescued cells from Lonafarnib-induced apoptosis in low serum medium, indicating that proteins rather than cytokines or growth factors in serum masks Lonafarnib’s pro-apoptotic effect. Therefore, we conclude that Lonafarnib is effective in inhibiting the growth of NSCLC cells either via growth arrest or induction of apoptosis without downregulation of Akt. http://dx.doi.org/10.4161/cbt.3.11.1176 http://www.landesbioscience.com/journals/cbt/article/1176/ article Research Paper 1538-4047 Yuangang Liu James P. Lagowski Gretchen E. Vanderbeek and Molly F. Kulesz-Martin cbt Facilitated search for specific genomic targets by p53 c-terminal basic DNA binding domain Landes Bioscience 2004-10-15 1102 - 1108 Cancer Biology & Therapy 3-11 Landes Bioscience p53 is a unique DNA binding protein with two distinct DNA binding domains, the central domain for sequence-specific DNA binding and the basic DNA binding domain (BD domain) for structure-specific DNA binding. In contrast to the apparent inhibitory effect of the BD domain on p53 binding to sequence-specific DNA in vitro, here we demonstrate that the BD domain enhances p53 binding to the endogenous p21Waf1 promoter and mediates rapid transactivation of p21Waf1. This paradox is resolved by the observation that the BD domain is required for rapid binding to non-sequence-specific genomic DNA (NS-DNA) as evident from global chromatin immunoprecipitation analysis of p53 DNA binding in vivo. This finding provides the first in vivo evidence from a eukaryotic system to support binding to NS-DNA as an intermediate step in searching specific sites as proposed by von Hippel and Berg. Furthermore, we speculate that binding to structure-specific DNA by the BD-domain is a mechanism for p53 rapid binding to genomic DNA from its free state to facilitate the search for its target sites in the genome undergoing genotoxic stress. http://dx.doi.org/10.4161/cbt.3.11.1189 http://www.landesbioscience.com/journals/cbt/article/1189/ article Research Paper 1538-4047 Niquiche Sangster-Guity Li-Ming Yu and Paulette McCormick cbt Molecular profiling of embryonal carcinoma cells following retinoic acid or histone deacetylase inhibitor treatment Landes Bioscience 2004-10-15 1109 - 1120 Cancer Biology & Therapy 3-11 Landes Bioscience Regulation of tissue homeostasis is crucial to disease prevention; cell division, cell cycle arrest, differentiation and apoptosis have to be tightly controlled in order to maintain this homeostasis. Retinoic acid (RA) and the histone deacetylase inhibitors (HDACIs) have profound effects on these processes and thus may be critical regulators of homeostasis. Consequently, RA and/or histone deacetylase inhibitors are currently being tested in clinical trials for a variety of cancers. Unfortunately, little is known of the Regulation of tissue homeostasis is crucial to disease prevention; cell division, cell cycle arrest, differentiation and apoptosis have to be tightly controlled in order to maintain this homeostasis. Retinoic acid (RA) and the histone deacetylase inhibitors (HDACIs) have profound effects on these processes and thus may be critical regulators of homeostasis. Consequently, RA and/or histone deacetylase inhibitors are currently being tested in clinical trials for a variety of cancers. Unfortunately, little is known of the overall affect of these compounds on cellular gene expression. Therefore, we decided to compare the effects of all-trans retinoic acid (ATRA) and a particular HDACI – Trichostatin A (TSA) - on an embryonal carcinoma (EC) cell line (F9) using gene chip analysis. We have focused particular attention on those genes that may be differentially affected by these compounds. Within the parameters established for this study, only 116 of the 12,488 genes examined were similarly regulated by ATRA and TSA: 75 positively and 41 negatively. An additional 70 genes were affected by only one of the compounds and 19 genes were actually inversely regulated. The gene set inversely regulated by ATRA and TSA includes several important patterning genes as well as the crucial tumor suppressor/promoter, transforming growth factor beta 1 (TGF?1). Promoter analysis suggests a motif that may regulate one set of these genes. This study provides the first comprehensive comparison of global gene expression on EC cells as affected by ATRA and a HDAC inhibitor (TSA); reveals new targets for ATRA and HDAC inhibitors; identifies a new regulatory motif; demonstrates that ATRA and HDAC inhibitors do not always act synergistically on gene expression; and examines particular questions regarding their concurrent clinical application.ral important patterning genes as well as the crucial tumor suppressor/promoter, transforming growth factor beta 1 (TGF?1). Promoter analysis suggests a motif that may regulate one set of these genes. This study provides the first comprehensive comparison of global gene expression on EC cells as affected by ATRA and a HDAC inhibitor (TSA); reveals new targets for ATRA and HDAC inhibitors; identifies a new regulatory motif; demonstrates that ATRA and HDAC inhibitors do not always act synergistically on gene expression; and examines particular questions regarding their concurrent clinical application. http://dx.doi.org/10.4161/cbt.3.11.1190 http://www.landesbioscience.com/journals/cbt/article/1190/ article Research Paper 1538-4047 Susobhan Sarkar Anirban Ghosh Joydeep Mukherjee Samares Chaudhuri and Swapna Chaudhuri cbt CD2-SLFA3/T11TS interaction facilitates immune activation and glioma regression by apoptosis Landes Bioscience 2004-10-15 1121 - 1128 Cancer Biology & Therapy 3-11 Landes Bioscience Objective: Exogenous application of T11TS/SLFA3 in glioma model had shown the regression of tumor load through immunopotentiation. The mechanistic module of this interaction on immunological synapse formation and resulting effect in glioma regression is searched for delineating immunotherapeutic efficacy of T11TS. Methods: After purification of T11TS/SLFA3 from sheep erythrocytes the glycoprotein was characterized by SDS-PAGE analysis and glycoprotein staining. The modulatory effect of T11TS application on glioma animals were studied by CD2 and MHC class II expression on peripheral lymphocytes, PMN, macrophages and intracranial microglia by flowcytometric analysis. Finally apoptotic killing of brain cells were studied through annevin-V expression and measuring fragmented cytoplasmic DNA by ELISA. Results: Compared to healthy normal counter-parts the CD2 receptor downregulation by ENU treatment in lymphocytes and PMN were upregulated with three consecutive doses of T11TS. Splenic antigen presenting macrophages and intracranial mocroglia had shown CD2 and MHC class II modulation simultaneously in their different subtypes. These receptor studies revealed significant boosting of the immune competent cells most effectively in second dose of T11TS whereas the third dose had some regulatory effect. Sharp increase of apoptosis in brain cells was found by phosphatidylserine externalization and presence of fragmented DNA in cytoplasm with application of T11TS in consecutive doses as a result of immune potentiation. Conclusion: Receptor studies revealed modulation of CD2 and MHC class II, two important constituents of immunological synapse successfully help to form the TCR-p-MHC complex and provide required co-stimulation for activation. Potentiated immune effector machinery was then directed to abrogate glioma by apoptosis signifying T11TS as an immunotherapeutic probe. http://dx.doi.org/10.4161/cbt.3.11.1214 http://www.landesbioscience.com/journals/cbt/article/1214/ article Research Paper 1538-4047 Yanfang Zheng Jiren Zhang and Zhiguo Rao cbt Ribozyme targeting HPV16 E6E7 transcripts in cervical cancer cells suppresses cell growth and sensitizes cells to chemotherapy and radiotherapy Landes Bioscience 2004-10-15 1129 - 1134 Cancer Biology & Therapy 3-11 Landes Bioscience Human Papillomavirus (HPV) is related to more than 90% of cervical cancer. The virus is shown to be essential for the induction and maintenance of the malignant phenotype in cervical cancer. In this report, we designed a hammerhead ribozyme Rz170 to specifically target the HPV16 E6E7 transcripts, and our results demonstrated that Rz170 can cleave HPV16 E6E7 transcripts effectively and with high specificity. When transfected into a HPV16 positive cervical cancer cell, CaSKi, the ribozyme reduced the expression of HPV16 E6 and E7 mRNA, and inhibited cell growth both in vitro and in vivo. The percentage of apoptosis cells was also increased. We found that Rz170 reduced the expression of the viral E6 and E7 proteins, and cellular c-myc, bcl-2 proteins, but increased the expression of p53 and Rb proteins. It is likely that the ribozyme inhibited cervical cancer cell growth by reducing the expression of the HPV16 E6 and E7gene, which may alter the expression of p53, Rb, c-myc and bcl-2, and led to apoptosis in cancer cells. We also found that CaSKi cells transfected with Rz170 showed increased sensitivity to cisplatin and radiation. Our study demonstrated the potential of Rz170 for treating cervical cancer, and the possibility of using a combined therapeutic strategy involving ribozyme, chemotherapy or radiotherapy. http://dx.doi.org/10.4161/cbt.3.11.1215 http://www.landesbioscience.com/journals/cbt/article/1215/ article Research Paper 1538-4047 Jan M. Woynarowski Barbara A. Woynarowska Alex V. Trevino Richard Salinas Terence S. Herman Stephen J. Waters and John R. MacDonald cbt Cell cycle effects and induction of premitotic apoptosis by irofulven in synchronized cancer cells Landes Bioscience 2004-10-15 1137 - 1142 Cancer Biology & Therapy 3-11 Landes Bioscience Unlike postmitotic cell death, direct premitotic apoptosis diminishes the risk of clonal selection and allows for the elimination of slowly growing cancer cells. This study characterized the ability to induce premitotic apoptosis by irofulven (hydroxymethylacylfulvene), a novel alkylating drug which targets cellular DNA and proteins. Irofulven effects were examined in HeLa-derived BH2 cancer cells with conditional overexpression of antiapoptotic Bcl-2. Cells were synchronized in either early S or in G1. Following 12 h exposure to irofulven, cells that were originally in early S accumulated in late S or remained in early S phase (at 0.5 and 2.5 µM drug, respectively). Drug treatment of cells in the G1 cohort prevented their entry into the S phase. Significant apoptosis was detected based on the appearance of sub-G1 particles and cells with DNA strand breaks in both G1 and S cohorts. Apoptotic cells were mostly recruited from the G1/S border ("G1" cohort) and from the S phase ("early S" cohort). All the cell cycle and apoptotic effects were only marginally affected by Bcl-2 overexpression. Similar results were obtained with irofulven-treated synchronized cultures of leukemic CEM cells. Collectively, these observations indicate that irofulven-treated cells become committed to death early. Neither active DNA replication nor traverse through mitosis are necessary for irofulven-induced cell death. The ability to promote direct premitotic apoptosis is likely to play a role in the consistently potent apoptotic effects of irofulven and its ability to cause tumor regression in vivo. http://dx.doi.org/10.4161/cbt.3.11.1216 http://www.landesbioscience.com/journals/cbt/article/1216/ article Research Paper 1538-4047 Hiroyuki Matsue Keiko Matsue Dale Edelbaum Michael Walters Akimichi Morita and Akira Takashima cbt New strategy for efficient selection of dendritic cell-tumor hybrids and clonal heterogeneity of resulting hybrids Landes Bioscience 2004-10-15 1145 - 1151 Cancer Biology & Therapy 3-11 Landes Bioscience Heterotypic hybrids created between dendritic cells (DC) and tumor cells represent an efficient approach for loading DC with tumor-associated antigens (TAA), and DC-tumor hybrid vaccines have shown promising outcomes in various preclinical and clinical studies. Conventional DC-tumor hybrid preparations, however, are unavoidably contaminated by DCtumor aggregates and DC loaded with tumor cell debris. Here we describe a new strategy for selecting genuine DC-tumor hybrids. A HAT-sensitive/zeocin-resistant DC clone (XS106-7 Zeo) was fused with a GFP-transduced fibrosarcoma clone (S1509a-GFP) by polyethylene glycol and heterotypic hybrid clones were established by limiting dilution in the presence of HAT and zeocin. CD45 (DC origin) and GFP (tumor origin) were both expressed in 91% (51/56 clones) of the resulting clones, indicating high efficiency of our strategy. Marked heterogeneity was observed among the hybrid clones, and only one clone exhibited characteristic features of DC (CD86 and I-A expression, dendritic morphology, T cellstimulatory capacity, and IL-1b, IL-6, and TNFa production), suggesting that only small fractions of DC-tumor hybrids acquire and maintain the properties of parental DC. Finally, vaccination with this hybrid clone protected mice from subsequent growth of S1509a tumor cells, documenting the in vivo activity of DC-tumor hybrids in the complete absence of exogenous TAA. http://dx.doi.org/10.4161/cbt.3.11.1217 http://www.landesbioscience.com/journals/cbt/article/1217/ article Research Paper 1538-4047 Alfredo Velasco Erick Riquelme Marcela Schultz Ignacio I. Wistuba Luis Villarroel Moon S. Koh and Frederick S. Leach cbt Microsatellite instability and loss of heterozygosity have distinct prognostic value for testicular germ cell tumor recurrence Landes Bioscience 2004-10-15 1152 - 1158 Cancer Biology & Therapy 3-11 Landes Bioscience Germ cell tumor (GCT) is the most common genitourinary malignancy of men between the ages of 18 and 35. Therapy is ultimately successful in over 90% of patients, however significant morbidity and mortality can be associated with adjuvant treatment and relapse. Molecular markers that predict treatment response and/or poor outcome would have immediate clinical benefit since adjuvant treatment could be selectively reserved for patients at higher risk for relapse and those patients most likely to respond to treatment. In order to identify potential prognostic molecular markers, we evaluated 118 GCT for microsatellite instability (MSI), loss of heterozygosity (LOH) and MSH2 immunostaining to identify tumors associated with relapse and/or poor outcome following initial surgical, medical and/or radiation therapy. MSI in 3 or more markers and/or low MSH2 staining were associated with relapse while LOH in the absence of MSI and/or high MSH2 staining were not. Twenty-five percent of GCT exhibited genetic instability in 3 or more microsatellite markers (MSI+ tumors), 15% exhibited LOH in the absence of MSI (LOH only tumors) and 44% exhibited decreased or absent MSH2 immunostaining (low MSH2 staining tumors). Thirty-six patients (30%) relapsed and 27 of these patients (75%) had MSI+ and/or low MSH2 staining tumors. Only 1 patient (3%) with an LOH only tumor and no patients with high MSH2 staining and LOH only tumors relapsed. Therefore distinct GCT subpopulations identified by detection of MSI, LOH and MMR expression are associated with different clinical outcomes. MMR deficient testicular GCT with increased frequency of MSI had an increased association with tumor recurrence compared to GCT with an intact MMR system and LOH in the absence of MSI. http://dx.doi.org/10.4161/cbt.3.11.1218 http://www.landesbioscience.com/journals/cbt/article/1218/ article Research Paper 1538-4047 Annette Schmidt Klaus Addicks and Wilhelm Bloch cbt Opposite effects of endostatin on different endothelial cells Landes Bioscience 2004-10-15 1162 - 1166 Cancer Biology & Therapy 3-11 Landes Bioscience Endostatin was described as an anti-angiogenic factor. Therefore endostatin looked to be a new way in anti-angiogenic treatment of cancer. Unfortunately, up to now no objective response were seen in clinical trials using endostatin. We compared two different endothelial cell types. Human umbilical vein endothelial cells (HUVEC) and endothelial cells derived from differentiated embryonic stem cells (eESC) were tested in view of endostatin induced proliferation, apoptosis, migration and endostatin binding. Both endothelial cell types had shown an opposite response to endostatin for all observed parameters in dependency of the used concentration. The quantity of HUVEC cells was slightly reduced to 84±8% by treating with 50 ng/ml endostatin whereas the eESC’s showed a significant increase up to 142±12% under same conditions (p=0.01). The observation that endostatin is able to evoke nonuniform response for proliferation, cell mount and migration of endothelial cells, with different endostatin binding characteristic, leads to the assumption that endostatin effect is strongly dependent from endothelial cell type. Furthermore the cell biological response at lower concentration on angiogenic eESC gives evidence for an angiogenic modulatory rather than a predicted anti-angiogenic role of endostatin. http://dx.doi.org/10.4161/cbt.3.11.1219 http://www.landesbioscience.com/journals/cbt/article/1219/ article Research Paper 1538-4047 John T. Murphy Jody M. Tucker Celestia Davis and Franklin G. Berger cbt Raltitrexed increases tumorigenesis as a single agent yet exhibits anti-tumor synergy with 5-fluorouracil in ApcMin/+ Mice1 Landes Bioscience 2004-10-15 1169 - 1176 Cancer Biology & Therapy 3-11 Landes Bioscience The thymidylate synthase (TS) inhibitors raltitrexed (RTX) and 5-fluorouracil (FUra) have shown promising anti-tumor activity in preclinical and clinical settings for the treatment of colorectal cancer. Though the effects of these two agents have been reasonably wellcharacterized in cell lines, knowledge of their modes of action in vivo is limited. Here, we utilize the ApcMin/+ mouse, an animal model of intestinal tumorigenesis, to study the effects of RTX treatment alone and in combination with FUra. Rather surprisingly, RTX monotherapy resulted in a dose dependent 4-10-fold increase in tumor number. The majority of these adenomas (74- 95%) were rather small (i.e., less than 1 mm in diameter) and exhibited loss of heterozygosity at the Apc locus, suggesting an increase in mutational events leading to tumor development. RTX augmented BrdU-labeling of crypt epithelial cells, and retarded the movement of these cells along the crypt-villus axis. Co-administration of FUra and RTX resulted in a significant reduction in tumor number compared to mice treated with either RTX or FUra alone (P < 0.0001). In addition, FUra abrogated the RTX-mediated increase in BrdU labeling. In all, the results show that RTX increases tumor burden in the ApcMin/+ mouse, yet enhances the anti-tumor effect of FUra. This is the first illustration of in vivo synergy of RTX and FUra in a genetically predisposed animal model. Possible mechanisms underlying the current observations are discussed. http://dx.doi.org/10.4161/cbt.3.11.1220 http://www.landesbioscience.com/journals/cbt/article/1220/ article Research Paper 1538-4047 Demetrios A. Spandidos cbt The cancer story Landes Bioscience 2004-10-15 1184 - 1186 Cancer Biology & Therapy 3-11 Landes Bioscience No abstract available. http://dx.doi.org/10.4161/cbt.3.11.1260 http://www.landesbioscience.com/journals/cbt/article/1260/ article Profiles in Science 1538-4047 na cbt Counting Circulating Tumor Cells: Moving Towards Early Detection of Response to Breast Cancer Therapy Landes Bioscience 2004-10-15 1039 - 1044 Cancer Biology & Therapy 3-11 Landes Bioscience A new blood test could change the way doctors treat women whose breast cancer has spread to other parts of their body. Using a technology that separates the cancer cells circulating in the blood of women with metastatic breast cancer, doctors are able to count these cells and determine within just three to four weeks whether a new treatment is working. "If you've started a new therapy, three to four weeks later it's usually too early for us to even begin to tell if the therapy is working. With this test, if you have elevated levels of cancer cells in your blood after three weeks of treatment, it's very likely your disease is going to progress quickly and it means probably you're on the wrong therapy," says Daniel Hayes, M.D., clinical director of the Breast Oncology Program at the University of Michigan Comprehensive Cancer Center. Traditionally, the most reliable way to determine if a therapy is effective is to run CT scans, bone scans and chest X-rays. But it takes three to four months of treatment before those tests will show if the treatment is making a difference. Other methods, such as examining the patient or running other blood tests, are usually not accurate. The idea of counting cancer cells in the blood is not new, but the techniques used until this point have been unreliable. This new method, using a technology called CellSearch, produces the same results every time. CellSearch was developed by Immunicon Corp. in Huntington Valley, Pa., and is marketed by Veridex LLC, a Johnson & Johnson company. About 250,000 women will be diagnosed with breast cancer this year, and 15 percent to 20 percent of patients will ultimately develop metastasis. Breast cancer most commonly spreads to the liver, lungs or bones. "Once a patient has developed metastatic breast cancer that we can find in the bones, the liver or the lung, we rarely, if ever, cure such a patient. We can treat her, but not as well as we'd like. And our goal of therapy for such a patient is to keep her quality of life as good as it can be, for as long as it can be," says Hayes, professor of Internal Medicine at the U-M Medical School. Treatment involves hormone therapy or chemotherapy, and oncologists have many different options to choose from. If one therapy proves ineffective, doctors may be able to switch the patient to a different treatment. "The clinician has two challenges," Hayes says. "One is which therapy is likely to work - and there may be several - with the fewest side effects. Then we have to wait and see whether that was the right choice because these therapies don't work in 100 percent of patients. And so the second challenge is, as a doctor, did I pick the right therapy to achieve that balance?" The benefit of this new test is patients would not have to spend months taking a drug - and dealing with its side effects - if it's not working. In a multicenter trial of the CellSearch technology, published in August in the New England Journal of Medicine, researchers at U-M and elsewhere found that in women who had elevated circulating tumor cell levels three to four weeks after beginning a new therapy, the cancer progressed within three months, compared to almost seven months progression-free for women with lower tumor cell levels. The women also had shorter survival when tumor cell levels were elevated: 10 months survival in the elevated group, compared to more than 18 months if levels were low. "I really think this could help us change the way we treat patients with metastatic disease by making better decisions and treating them more efficiently. By not prolonging therapy that's not likely to work, we can go to therapy that might be more likely to work," Hayes says. Detecting breast cancer early: * Do a breast self-exam every month. * Have your doctor perform a breast exam at least once a year. * Have a mammogram every year after age 50. * Never ignore a lump or change in the look or feel of your breast. Remember that a cancerous tumor is most often not painful. Tips for women diagnosed with breast cancer: * Discuss your cancer and treatment options with your doctor so that you know your choices. Get a second opinion on treatment options from another doctor. * Tell your doctor if your treatment causes discomfort. Most often there are ways to relieve the discomfort. * Get routine checkups after your treatment is done. * Keep doing monthly self-exams, even if both your breasts have been removed, to look for any cancer that has come back. * Rest frequently and follow the treatment plan as discussed with your doctor. * Follow an exercise regimen when you've finished your treatments. * Consult with a dietitian to improve your diet to heal tissue after treatment and to fight further cancer. * Join a breast cancer support group. http://dx.doi.org/10.4161/cbt.3.11.1285 http://www.landesbioscience.com/journals/cbt/article/1285/ article News 1538-4047 Ramona Britto and Kumaravel Somasundaram cbt Highly specific targeting of HPV genes using ribozymes Landes Bioscience 2004-10-15 1135 - 1136 Cancer Biology & Therapy 3-11 Landes Bioscience commentary to Ribozyme Targeting HPV16 E6E7 Transcripts in Cervical Cancer Cells Suppresses Cell Growth and Sensitizes Cells to Chemotherapy and Radiotherapy Yanfang Zheng, Jiren Zhang and Zhiguo Rao http://dx.doi.org/10.4161/cbt.3.11.1296 http://www.landesbioscience.com/journals/cbt/article/1296/ article Commentary 1538-4047 Katherine L. Nathanson and David J. Vaughn cbt Somatic genetics of testicular cancer in relationship to prognosis Landes Bioscience 2004-10-15 1159 - 1161 Cancer Biology & Therapy 3-11 Landes Bioscience commentary to Microsatellite Instability and Loss of Heterozygosity Have Distinct Prognostic Value for Testicular Germ Cell Tumor Recurrence Alfredo Velasco, Erick Riquelme, Marcela Schultz, Ivan Wistuba, Luis Villarroel, Moon S. Koh and Fredrick S. Leach http://dx.doi.org/10.4161/cbt.3.11.1298 http://www.landesbioscience.com/journals/cbt/article/1298/ article Commentary 1538-4047 Timothy K. MacLachlan and Mohanraj Dhanabal cbt Insights into differential endostatin activity Landes Bioscience 2004-10-15 1167 - 1168 Cancer Biology & Therapy 3-11 Landes Bioscience commentary to Opposite Effects of Endostatin on Different Endothelial Cells Annette Schmidt, Klaus Addicks and Wilhelm Bloch http://dx.doi.org/10.4161/cbt.3.11.1300 http://www.landesbioscience.com/journals/cbt/article/1300/ article Commentary 1538-4047 Eric Bernhard cbt Farnesyltransferase inhibition: Who are the aktors? Landes Bioscience 2004-10-15 1099 - 1101 Cancer Biology & Therapy 3-11 Landes Bioscience Commentary to The Farnesyltransferase Inhibitor Lonafarnib Induces Growth Arrest or Apoptosis of Human Lung Cancer Cells without Downregulation of Akt Shi-Yong Sun, Zhongmei Zhou, Ruoxiang Wang, Haian Fu and Fadlo R. Khuri http://dx.doi.org/10.4161/cbt.3.11.1301 http://www.landesbioscience.com/journals/cbt/article/1301/ article Commentary 1538-4047 Florian Karreth and David A. Tuveson cbt Twist induces an epithelial-mesenchymal transition to facilitate tumor metastasis Landes Bioscience 2004-10-15 1058 - 1059 Cancer Biology & Therapy 3-11 Landes Bioscience Tumor metastasis--the spreading of primary tumor cells to distal organs--is the major cause of death of cancer patients. The metastatic process consists of four distinct steps, invasion, intravasation, extravasation, and metastatic growth, and primary tumor cells need to acquire different genetic characteristics to accomplish each step. The main players during the metastatic process remain, however, largely unknown. A recent report in Cell by Robert Weinberg’s group (Yang et al., Cell. 2004 Jun 25;117(7):927-39) adds the transcription factor Twist to the list of metastatis regulators. Suppression of Twist expression in tumor cells inhibits the metastatic potential, whereas its overexpression induces an epithelial-mesenchymal transition (EMT) in epithelial cells. This study provides direct evidence that EMT may be an essential process during metastasis and should appropriately stimulate further investigations of EMT in many laboratories. http://dx.doi.org/10.4161/cbt.3.11.1302 http://www.landesbioscience.com/journals/cbt/article/1302/ article Journal Club 1538-4047 Tanyifor M. Tohnya and William D. Figg II cbt Immunomodulation of multiple myeloma Landes Bioscience 2004-10-15 1060 - 1061 Cancer Biology & Therapy 3-11 Landes Bioscience Multiple myeloma is a multi-process disease, and these different processes are responsible for the reduced sensitivity to chemotherapy and radiotherapy, hence the relapse and refractory nature of multiple myeloma. Emphasis is now placed on the hypothesis that myeloma cell growth, inhibition of apoptosis and drug resistance are dependent on immunomodulatory cytokines such as IL-6 and pro-angiogenic factors such as VEGF. In addition to its anti-angiogenic effects, the immunomodulatory properties of thalidomide make it a possible therapy for patients with advanced multiple myeloma. This has lead to the clinical development of a number of immunomodulatory thalidomide analogues (IMiDs) which are more potent and have less side effects than the parent drug, thalidomide. In the August 15th issue of Journal of Clinical Oncology, Schey SA et al. suggested that an IMiD (CC-4047) maybe efficacious due to T-cell co-stimulation, and safe in patients with relapsed or refractory multiple myeloma. This article demonstrates a supporting role for IMiDs as immunomodulatory adjuvant therapy. http://dx.doi.org/10.4161/cbt.3.11.1303 http://www.landesbioscience.com/journals/cbt/article/1303/ article Journal Club 1538-4047 cbt Lithium Protects Mouse Hippocampus from Ionizing Radiation Landes Bioscience 2004-10-15 1039 - 1044 Cancer Biology & Therapy 3-11 Landes Bioscience Patients who undergo radiation for treatment of brain tumors may survive their cancer only to have lasting memory and learning deficiencies, the impact of which can be particularly devastating for children. Now, researchers at the Vanderbilt-Ingram Cancer Center have discovered that lithium, a drug commonly used to treat bipolar disorder and other mental illnesses, can protect the brain cells involved in learning and memory from radiation damage. While the work has been conducted in cell culture and animal studies thus far, clinical trials are expected to be conducted soon to test whether the drug can protect humans from cognitive deficits as a result of cranial radiation therapy. The researchers presented their work during the 46th annual meeting of the American Society for Therapeutic Radiology and Oncology, earlier this week in Atlanta. "In addition to killing cancer cells, radiation can cause cell death - apoptosis - in normal cells as well," said Dennis Hallahan, M.D., professor and chair of Radiation Oncology at Vanderbilt University School of Medicine in Nashville, Tenn. "Particularly susceptible are neurons in the hippocampus, the part of the brain that plays a crucial role in learning and memory." Lithium is an inhibitor of a protein that causes apoptosis called glycogen synthase kinase 3 b. Studies suggest that it may protect neurons from a variety of cytotoxic insults, including observations that the incidence of Alzheimer's disease - which leads to progressive and profound memory loss - is lower among patients who take lithium for mental illness, Hallahan said. The researchers observed in animal models that a single radiation dose of 5 Gy caused a massive amount of apoptosis in the hippocampus but not in other areas of the brain. However, treatment of a mouse hippocampus cell with lithium for a week prior to 3 Gy of radiation resulted in a 60 percent increase in cell survival; a week's treatment with lithium prior to a radiation dose of 6 Gy resulted in a 70 percent increase in cell survival. The researchers also observed animals in a maze to determine long-term effects on memory and learning, and found that the animals pre-treated with lithium performed better than those who did not receive lithium prior to radiation. The team further noted that lithium did not appear to protect other types of brain cells studied, suggesting that its effects may be selective for neurons. "Lithium may therefore provide a means of attenuating long-term cognitive deficits in patients treated with cranial irradiation," the researchers said. Co-authors include Eric Edwards, William Whetsell, Eric Shinohara, Jiahuai Tan and Kate Osusky. The work was funded by the National Cancer Institute. The study was one of 17 presented by Vanderbilt-Ingram Cancer Center investigators during the meeting of the world's largest radiation oncology society, with 7,500 members. For more information, visit ASTRO, the website of the American Society for Therapeutic Radiology And Oncology. http://dx.doi.org/10.4161/cbt.3.11.1313 http://www.landesbioscience.com/journals/cbt/article/1313/ article News 1538-4047 Paul Dent and Steven Grant cbt Irofulven: Resurgence for alkylating therapy in cancer? Landes Bioscience 2004-10-15 1143 - 1144 Cancer Biology & Therapy 3-11 Landes Bioscience Commentary to Cell Cycle Effects and Induction of Premitotic Apoptosis by Irofulven in Synchronized Cancer Cells Jan M. Woynarowski, Barbara A. Woynarowska, Alex V. Trevino, Richard Salinas, Terence S. Herman, Stephen J. Waters and John R. MacDonald http://dx.doi.org/10.4161/cbt.3.11.1306 http://www.landesbioscience.com/journals/cbt/article/1306/ article Commentary 1538-4047 Tom C. Karagiannis and Assam El-Osta cbt siRNAs: Mechanism of RNA interference, In vivo and potential clinical applications Landes Bioscience 2004-10-15 1069 - 1074 Cancer Biology & Therapy 3-11 Landes Bioscience Small interfering RNAs are currently the most widely used nucleic acid-based sequence-specific gene silencing molecules. These molecules mediate RNA interference - a natural post-transcriptional gene-silencing pathway. Given the high reliability and higher efficiency of small interfering RNA-mediated RNA interference, compared to earlier reverse genetic technologies, this is now the preferred technique in functional genomics. Furthermore, the exquisite specificity and exceptional gene-silencing potency of small interfering RNAs has resulted in intense research related to potential target-specific therapeutic applications of these molecules. This review will discuss the mechanism of RNA interference and applications of the pathway in molecular biology including functional genomics will be overviewed. The article will outline in vivo and potential clinical applications of small interfering RNA molecules. http://dx.doi.org/10.4161/cbt.3.11.1309 http://www.landesbioscience.com/journals/cbt/article/1309/ article Focus on the Liver 1538-4047 cbt Short CAG Repeat in Androgen Receptor Respond Better to Androgen Ablation Landes Bioscience 2004-10-15 1039 - 1044 Cancer Biology & Therapy 3-11 Landes Bioscience Physician-scientists at the University of Miami Sylvester Comprehensive Cancer Center have identified a way to predict which prostate cancer patients may benefit most from continued androgen ablation therapy to block hormones. The research was presented at the 46th annual meeting of the American Society for Therapeutic Radiology and Oncology in Atlanta, Georgia, October 3 -7. "We found a subgroup of patients that benefited from androgen ablation therapy, regardless of other known prognostic factors in prostate cancer," said May Abdel-Wahab, M.D., associate professor of Clinical Radiation Oncology at the UM School of Medicine and a member of the Genitourinary Cancer Site Disease Group at UM/Sylvester. The subgroup of patients in the study have what are called short CAG repeats. CAG stands for cytosine, adenosine and guanosine, three nucleotides which are the building blocks of DNA. These three nucleotides appear repeatedly on androgen receptor genes, with longer repeats in some people. CAG repeats number anywhere from 14 to 32 in the androgen receptors of healthy people. "Patients with lower CAG repeats who received hormone ablation and radiation on the study had improved local disease control over those treated with radiation alone, regardless of their Gleason score, stage or age," said Abdel-Wahab, the principal investigator of the study. UM researchers worked with the Radiation Therapy Oncology Group, a top national cancer research collaborative, to acquire prostate tumor samples from patients who had been treated on the RTOG 86-10 study. They isolated androgen receptor lengths using polymerase chain reaction (PCR), a quick way to analyze DNA, and measured the percentage of positive androgen receptors by flow cytometry (analyzing the content of samples with a laser). "We found that people with short CAG repeats (fewer than 19) that were treated with hormone ablation and radiation actually did better in terms of local tumor growth control," said Abdel-Wahab. "However it didn't affect overall survival in these patients." In this study, the hormone blocking therapy was temporary and was given for only 4 months. "If you prevent androgens for a long time you might be able to slow down the progression of disease in these patients, or maintain a longer remission." "If these patients had gotten long-term androgen ablation the favorable results may have been preserved because they're the ones who are far more likely to have their cancer stimulated by the presence of androgens," said Abdel-Wahab. "You could possibly choose the people who might benefit from long-term hormonal therapy, and that's why it's exciting." Prostate cancer is the most common malignancy in the United States, with about 230,000 new cases diagnosed every year. Nearly 30,000 men will die from prostate cancer this year. In Florida alone, more than 17,000 new cases will be diagnosed and more than 2,200 people will die. If you want to learn more about this study, please call (305) 243-1000. UM/Sylvester was founded in 1992 to provide comprehensive cancer services and today serves as the hub for cancer-related research, diagnosis, and treatment at the University of Miami School of Medicine. UM/Sylvester handles more than 1,100 inpatient admissions annually, performs 2,800 surgical procedures, and treats 2,900 new cancer patients. All UM/Sylvester physicians are on the faculty of the University of Miami School of Medicine, South Florida's only academic medical center. In addition, UM/Sylvester physicians and scientists are engaged in more than 150 clinical trials and receive more than $30 million annually in research grants. UM/Sylvester at Deerfield Beach recently opened to better meet the needs of residents of Broward and Palm Beach Counties. This 10,000 square-foot facility at I-95 and S.W. 10th Street offers appointments with physicians from six cancer specialties, complementary therapies from the Courtelis Center, and education and outreach events. http://www.sylvester.org. http://dx.doi.org/10.4161/cbt.3.11.1312 http://www.landesbioscience.com/journals/cbt/article/1312/ article News 1538-4047 cbt Targeting Drug Transporter Mrp4 Increases Topotecan Accumulation in the CNS Landes Bioscience 2004-10-15 1039 - 1044 Cancer Biology & Therapy 3-11 Landes Bioscience A protein called Mrp4 blocks the access of the anti-cancer drug topotecan into the brain by transporting this agent back into the bloodstream, thus reducing the ability of this agent to reach tumors. Results from a series of studies by investigators at St. Jude Children's Research Hospital are published in a recent issue of Molecular and Cellular Biology (MCB). The St. Jude team, which developed a mouse model lacking the Mrp4 protein, says study results in both mice and tissue cultures suggest that the therapeutic efficacy of drugs targeting central nervous system tumors might be improved by inhibiting this protein, a type of molecule called an ABC-dependent transporter. The study showed that Mrp4 works at two levels: by binding to topotecan and transporting it away from the brain Mrp4 restricts the drug's penetration into the brain from the bloodstream; and it protects brain cells from accumulating toxic levels of topotecan molecules that do escape the bloodstream. "The ability of Mrp4 to protect the brain from toxins can be a liability in people with brain cancer when this protein also blocks therapeutic drugs from reaching CNS tumors," said John Schuetz, Ph.D., an associate member of the St. Jude Department of Pharmaceutical Sciences. Schuetz is senior author of the article. The investigators discovered that when topotecan was injected into the veins of specially bred mice that lack Mrp4, the drug accumulated to greater than normal levels in the brain tissue and the fluid that surrounds the brain-the cerebrospinal fluid (CSF). The finding strongly suggests that the natural role of Mrp4 is to block the passage of certain toxic molecules, which chemically resemble topotecan, from leaving the bloodstream and entering the brain. The cells lining the walls of brain capillaries are tightly joined to form a barrier that prevents most substances from leaving the blood. This cellular barrier, called the blood-brain barrier, prevents certain substances from leaving the bloodstream and entering the brain. Mrp4 in the blood-brain barrier also prevents substances from entering the brain by transporting them back into the blood as they pass into the cells of this barrier. Using antibodies against Mrp4 the investigators found that this protein is located in the brain's capillaries as well as in membranes of the choroid plexus-the folds within the brain ventricles that make and release CSF. "This dual location for Mrp4 is unusual for this type of transporter," Schuetz said. "It suggests that Mrp4 blocks specific molecules from leaving the capillaries. And if such molecules slip out of the blood into the choroid plexus, Mrp4 shuttles them back out of the brain and into the blood before they can cause damage." The investigators also showed that isolated cells that were modified to over-express Mrp4 did not accumulate as much topotecan as cells lacking this protein. This is strong evidence that over-expression of Mrp4 in tumors contributes to topotecan resistance in patients. "Our work has important implications for therapies that target brain tumors with specific types of drugs that are transported by Mrp4," Schuetz said. "There is an expanding array of these types of drugs being developed; and unless there is a way to block Mrp4 when giving these agents, the effectiveness of these new agents could be significantly compromised." Other authors of this study are Markos Leggas, Masashi Adachi, Daxi Sun, Guoqing Du, Kelly E. Mercer, Yanli Zhuang, John C. Panetta, Brad Johnston and Clinton F. Stewart (St. Jude); George L. Scheffer and Rik J. Scheper (VU Medical Center, Amsterdam, The Netherlands); and Peter Wielinga (The Netherlands Cancer Institute, Amsterdam). This work was supported in part by NIH, a Cancer Center Support Grant, the Dutch Cancer Society and ALSAC. St. Jude Children's Research Hospital St. Jude Children's Research Hospital is internationally recognized for its pioneering work in finding cures and saving children with cancer and other catastrophic diseases. Founded by late entertainer Danny Thomas and based in Memphis, Tennessee, St. Jude freely shares its discoveries with scientific and medical communities around the world. No family ever pays for treatments not covered by insurance, and families without insurance are never asked to pay. St. Jude is financially supported by ALSAC, its fundraising organization. http://dx.doi.org/10.4161/cbt.3.11.1311 http://www.landesbioscience.com/journals/cbt/article/1311/ article News 1538-4047 cbt TNF and Interferon-Gamma Target Myosin Heavy Chain in Cancer Cachexia Landes Bioscience 2004-10-15 1039 - 1044 Cancer Biology & Therapy 3-11 Landes Bioscience The often-fatal muscle wasting that accompanies many types of cancer is not simply a loss of muscle proteins generally, but seems to occur through a selective loss of particular muscle proteins, according to new research. The study, led by Ohio State University cancer researchers, showed that muscle wasting, also known as cachexia, results in the specific degradation of a protein known as myosin heavy chain (MyHC), which makes up 40 percent of the protein inside muscle cells that are responsible for muscle contraction. "The finding gives us new insight into how the mechanism of muscle wasting, something that is still poorly understood," says Denis C. Guttridge, assistant professor of molecular virology, immunology and medical genetics, and a researcher with The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute. "This study tells us that cachexia does not simply result from a general reduction of muscle proteins, but instead results from the loss of selective proteins affected during wasting. This in turns means there may be key proteins, such as myosin, that if rescued might allow us to preserve the muscle mass and prevent the process. It opens the door to possible future treatments." To the researchers' surprise, the study also suggested that the loss of muscle proteins can occur through at least two different molecular mechanisms. The findings were published in a recent issue of the Journal of Clinical Investigation. Cachexia occurs in several life-threatening diseases, including certain cancers, AIDS, congestive heart failure and the blood infection known as sepsis. Wasting can occur in late-stage cancers of the lung, pancreas and upper digestive system. It is thought to be responsible for about 30 percent of cancer deaths, Guttridge says. Unlike starvation, which depletes fat stores but leaves muscle tissue alone, wasting results in the loss of both fat and skeletal muscle. Currently, muscle wasting is thought to be caused by a general loss of muscle protein. The loss is thought to be triggered by certain signaling molecules produced by immune-system cells, and by cancer cells. These wasting-related signaling molecules belong to a class of molecules known as cytokines and include tumor necrosis factor (TNF) and interferon (IFN)-gamma. The study by Guttridge and his colleagues sought to identify the proteins inside muscle cells that are targeted by TNF and IFN-gamma. The investigators examined four core proteins involved in muscle contraction -- actin, myosin, troponin and tropomyosin - and specifically asked whether muscle wasting causes the loss of some or all four of those proteins. The researchers studied the question three different ways: by applying TNF and IFN-gamma to muscle cells growing in laboratory culture, by injecting mice with TNF and IFN-gamma-producing immune cells and by using mice carrying a human tumor. Muscle tissue was removed from the mice and analyzed for changes in the levels of the four proteins. In all three cases, only the MyHC protein was affected. However, says Guttridge, "We were surprised to find that different mechanisms could lead to the loss of the myosin protein, perhaps depending on which signal induced the wasting." Generally, Guttridge says, muscle proteins are lost through a process that first tags the proteins for destruction by enzymes that later cut them up. That's how the MyHC molecules were destroyed in the cultured muscle cells. In muscle removed from mice, however, MyHC levels fell because the TNF and IFN-gamma blocked the cell's ability to make the protein. Overall, Guttridge says, "Our data strongly suggest that signaling molecules like TNF and IFN-gamma do not cause muscle wasting by triggering a general loss of muscle proteins, but rather that they selectively target certain proteins, one of which is myosin heavy chain protein." Other OSU researchers involved in this study were Swarnali Acharyya, Katherine J. Ladner, Jeffrey Damrauer and Steven Swoap. Funding from the National Cancer Institute and the V Foundation supported this research. The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute encompasses six interdisciplinary research programs and more than 200 investigators. The OSU CCC - James is a founding member of the National Comprehensive Cancer Network; its investigators conduct research on the prevention, detection, diagnosis and treatment of cancer, generating over $95 million annually in external funding; OSU's James Cancer Hospital is consistently ranked by U.S. News & World Report as one of America's best cancer hospitals. http://dx.doi.org/10.4161/cbt.3.11.1314 http://www.landesbioscience.com/journals/cbt/article/1314/ article News 1538-4047 cbt 3-Bromopyruvate Blocks Energy Metabolism and Liver Cancer Landes Bioscience 2004-10-15 1039 - 1044 Cancer Biology & Therapy 3-11 Landes Bioscience Building on their earlier work, Johns Hopkins researchers have discovered that an apparently nontoxic cellular "energy blocker" can eradicate large liver tumors grown in rats. Six months to more than a year after treatment was stopped, the rats are still cancer free. While the results are dramatic, clinical trials with the chemical, 3-bromopyruvate, are likely some years away, says the study's leader, Young Ko, Ph.D., assistant professor of radiology and biological chemistry. If tests in the lab continue to be promising, however, the chemical or one like it may become an option for treating advanced liver cancers and perhaps other tumors in people. "Liver cancer usually isn't detected in people until it's difficult or impossible to treat, and many other aggressive cancers spread to the liver, so we need more treatment options," says Peter Pedersen, Ph.D., professor of biological chemistry in the Institute for Basic Biomedical Sciences at Johns Hopkins. "The compound Dr. Ko tested in animals targets a fundamental process cancer cells need to survive, can kill big tumors, and appears so far to have little or no effect on normal tissues." In fact, Ko says she hasn't been able to find a toxic dose of the compound, which blocks the two ways cancer cells make energy. In earlier experiments with rabbits with liver cancer, reported in 2002, no obvious toxic effects were seen, either. There is a patent pending on possible cancer applications of the compound. While the details of normal cells' protection are still unclear, the scientists suggest cancer cells well-known appetite for sugar might be behind their demise. Ko, who first studied the compound as a graduate student at Washington State University in 1990 and initiated its study at Hopkins, has shown that it completely blocks cancer cells' conversion of sugar into usable energy, a process necessary to fuel the cells' functions and growth. "We believe this is the first time that a drug has blocked both ways cancer cells make energy and are very happy that it seems so effective against advanced liver cancers," says Ko. "Usually researchers don't try to attack advanced cancers because success seems unlikely. But these are the very cancers we must learn to defeat if we are to win the war on cancer." Sugar, or glucose, is brought into cells and converted into useable energy, a molecule called ATP, by either of two processes. Another product of this conversion, a molecule called lactate, is then taken out of the cell by specialized transporters. But because cancer cells use so much more sugar and make so much more lactate than normal cells, the researchers suggest cancer cells may be riddled with more of the "two-way streets" that transport lactate. And because 3-bromopyruvate looks very similar to lactate, it might travel those same roads, sneaking into cancer cells like a Trojan horse, suggests Ko. In her latest experiments, described in the Nov. 5 issue of Biochemical and Biophysical Research Communications and available online now, Ko found that treating rat liver cancer cells with 3-bromopyruvate halted the cells' production of ATP within 30 minutes, and visual evidence of the cells' self-destruction was apparent almost immediately. Four times as much of the compound was necessary to begin decreasing ATP production in normal liver cells. Turning to animal studies, Ko injected rat liver cancer cells into either the abdomen or the upper back of 33 rats. Nineteen of the animals received daily injections of the compound into the tumor site for five days or longer, which caused all of the cancers to disappear within four weeks. The rats otherwise appeared unaffected, although Ko will examine the animals when they are euthanized -- probably for old age. The 14 untreated animals that served as controls were euthanized within 10 days because of their tumors' rapid growth. To be sure that the compound had completely eradicated the tumors in the treated animals, Ko and Pedersen collaborated with radiologist Martin Pomper, M.D., Ph.D., Yuchuan Wang, Ph.D., and James Fox. They used radioactive glucose to take PET scans of four of the rats and found that "hot spots" of high uptake disappeared within a few weeks of treatment. PET scans are commonly used to diagnose or stage cancers in people because of tumors' appetite for glucose. Ko is now studying the compound's effects on human cancer cell lines in the lab, and will begin studying it in animal models of breast cancer shortly. The researchers also are planning to examine the compound's effects in an animal model of an aggressive non-liver cancer that spreads to the liver. The research was funded by the National Cancer Institute and the Johns Hopkins Department of Radiology. Authors on the paper are Ko, Wang, Pomper, Pedersen, Barbara Smith, David Rini, Michael Torbenson and Joanne Hullihen, all of Johns Hopkins. http://dx.doi.org/10.4161/cbt.3.11.1317 http://www.landesbioscience.com/journals/cbt/article/1317/ article News 1538-4047 cbt Genetic Damage in Tumor Stroma Contributes to Tumor Growth Landes Bioscience 2004-10-15 1039 - 1044 Cancer Biology & Therapy 3-11 Landes Bioscience Normal cells that live among the cancer cells in a tumor may not be the innocent bystanders they are usually assumed to be. A study led by researchers at The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute has found that the normal cells in tumors, known collectively as the tumor stroma, may lose more regions of DNA than do the cancer cells in the course of tumor development. When DNA is lost, the genes located in those regions are also lost. Normal cells that live among the cancer cells in a tumor may not be the innocent bystanders they are usually assumed to be. A study led by researchers at The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute has found that the normal cells in tumors, known collectively as the tumor stroma, may lose more regions of DNA than do the cancer cells in the course of tumor development. When DNA is lost, the genes located in those regions are also lost. "Cancer geneticists have looked upon the stroma as just innocent soil that passively receives the seed in which cancer grows," says Dr. Charis Eng, the Dorothy E. Klotz Chair of Cancer Research and director of the clinical cancer genetics program. "But our study indicates that genetic damage occurs in stromal tumors cells, and that that damage may play an important role in tumor development." The findings might help explain why tumors often behave differently, and respond differently to treatment, in people with seemingly identical cancers. The genetic changes in stromal cells also may provide new targets for future anti-cancer drugs and present a new strategy for treating and preventing cancer, says Eng, a recipient of the Doris Duke Distinguished Clinical Scientist Award. The study is published in the Oct. 15 issue of the journal Cancer Research. How the DNA damage occurs in stromal cells isn't yet known, but it might result from exposure to carcinogens, Eng says. It's also too soon to say how genetic damage to stromal cells might influence tumor growth. However, stromal cells can produce growth factors and other substances that can influence the behavior of cancer cells. The loss of chromosome regions may result in the loss of genes that control these substances. Stromal cells may also produce factors that limit the growth of nearby cells. Loss of genes for such factors would remove those inhibitors and allow cancer cells to grow. "But those are only hypotheses," Eng says. "I think that the stroma plays an important role in enabling a tumor to invade neighboring tissue and spread. If that proves to be true, someone may someday develop a drug that targets stroma cells and prevents the cancer from spreading." Eng and her colleagues analyzed 134 tissue samples from invasive breast tumors. They examined stromal cells known as fibroblasts, the major component of the tumor stroma. Fibroblasts produce the fibrous scaffolding in tumors and normal tissues. (Stromal cells also include immune cells, fat cells and blood vessel cells.) The investigators used 381 molecular markers scattered throughout the human genome (the entire set of human chromosomes). The markers served as signposts that identify various regions of the 46 human chromosomes. Among the fibroblasts, the researchers found that 38 markers - or 38 regions of DNA - were lost from 19 different chromosomes. When the researchers then looked for the markers in the cancer cells, they found that 19 regions of DNA were lost from 15 different chromosomes. This indicates that more DNA regions may be lost in a tumor's stromal cells than in its cancer cells. Furthermore, the losses were not spread randomly over the chromosomes. Instead, they were clustered in specific regions, or hotspots, on chromosomes, suggesting that they may play a role in tumor development. The researchers are now looking for correlations between the stromal genetic damage seen in patients' tumors and how those tumors behave and respond to therapy. Other OSU researchers involved in this study were Koichi Fukino, a postdoctoral researcher; Lei Shen, assistant professor in the School of Public Health; Satoshi Matsumoto, postdoctoral researcher; and Carl D. Morrison, assistant professor of pathology. Funding from the V Foundation and the National Cancer Institute supported this research. The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute encompasses six interdisciplinary research programs and more than 200 investigators. The OSU CCC - James is a founding member of the National Comprehensive Cancer Network; its investigators conduct research on the prevention, detection, diagnosis and treatment of cancer, generating over $95 million annually in external funding; and OSU's James Cancer Hospital is consistently ranked by U.S. News & World Report as one of America's best cancer hospitals. "Cancer geneticists have looked upon the stroma as just innocent soil that passively receives the seed in which cancer grows," says Dr. Charis Eng, the Dorothy E. Klotz Chair of Cancer Research and director of the clinical cancer genetics program. "But our study indicates that genetic damage occurs in stromal tumors cells, and that that damage may play an important role in tumor development." The findings might help explain why tumors often behave differently, and respond differently to treatment, in people with seemingly identical cancers. The genetic changes in stromal cells also may provide new targets for future anti-cancer drugs and present a new strategy for treating and preventing cancer, says Eng, a recipient of the Doris Duke Distinguished Clinical Scientist Award. The study is published in the Oct. 15 issue of the journal Cancer Research. How the DNA damage occurs in stromal cells isn't yet known, but it might result from exposure to carcinogens, Eng says. It's also too soon to say how genetic damage to stromal cells might influence tumor growth. However, stromal cells can produce growth factors and other substances that can influence the behavior of cancer cells. The loss of chromosome regions may result in the loss of genes that control these substances. Stromal cells may also produce factors that limit the growth of nearby cells. Loss of genes for such factors would remove those inhibitors and allow cancer cells to grow. "But those are only hypotheses," Eng says. "I think that the stroma plays an important role in enabling a tumor to invade neighboring tissue and spread. If that proves to be true, someone may someday develop a drug that targets stroma cells and prevents the cancer from spreading." Eng and her colleagues analyzed 134 tissue samples from invasive breast tumors. They examined stromal cells known as fibroblasts, the major component of the tumor stroma. Fibroblasts produce the fibrous scaffolding in tumors and normal tissues. (Stromal cells also include immune cells, fat cells and blood vessel cells.) The investigators used 381 molecular markers scattered throughout the human genome (the entire set of human chromosomes). The markers served as signposts that identify various regions of the 46 human chromosomes. Among the fibroblasts, the researchers found that 38 markers - or 38 regions of DNA - were lost from 19 different chromosomes. When the researchers then looked for the markers in the cancer cells, they found that 19 regions of DNA were lost from 15 different chromosomes. This indicates that more DNA regions may be lost in a tumor's stromal cells than in its cancer cells. Furthermore, the losses were not spread randomly over the chromosomes. Instead, they were clustered in specific regions, or hotspots, on chromosomes, suggesting that they may play a role in tumor development. The researchers are now looking for correlations between the stromal genetic damage seen in patients' tumors and how those tumors behave and respond to therapy. Other OSU researchers involved in this study were Koichi Fukino, a postdoctoral researcher; Lei Shen, assistant professor in the School of Public Health; Satoshi Matsumoto, postdoctoral researcher; and Carl D. Morrison, assistant professor of pathology. Funding from the V Foundation and the National Cancer Institute supported this research. The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute encompasses six interdisciplinary research programs and more than 200 investigators. The OSU CCC - James is a founding member of the National Comprehensive Cancer Network; its investigators conduct research on the prevention, detection, diagnosis and treatment of cancer, generating over $95 million annually in external funding; and OSU's James Cancer Hospital is consistently ranked by U.S. News & World Report as one of America's best cancer hospitals. http://dx.doi.org/10.4161/cbt.3.11.1319 http://www.landesbioscience.com/journals/cbt/article/1319/ article News 1538-4047 cbt Margaret Spitz Honored with Distinguished University Chair Landes Bioscience 2004-10-15 1039 - 1044 Cancer Biology & Therapy 3-11 Landes Bioscience The University of Texas Board of Regents has appointed a renowned epidemiologist at The University of Texas M. D. Anderson Cancer Center to a prestigious Distinguished University Chair, only the third such chair awarded at M. D. Anderson. The first woman in The University of Texas System to receive this distinction, Margaret R. Spitz, M.D., chair of the Department of Epidemiology, was honored with the Olga Keith Wiess Distinguished University Chair for Cancer Research, which carries a $2.3 million endowment. The Distinguished University Chair is the highest level of endowed position within the UT System. Spitz is a nationally recognized epidemiologist and expert on tobacco-related cancers. Her research has focused on reducing overall risk for lung cancer, a disease that remains the leading cancer killer in women and men in the United States. "I am truly honored to receive this award, and am especially grateful for this opportunity to expand our epidemiological research programs," Spitz says. Spitz has held the Olga Keith Wiess Chair for Cancer Research at M. D. Anderson since 1998, with the award upgraded to Distinguished Chair in 2003 and now to Distinguished University Chair. "Dr. Spitz' contributions throughout her career have had a significant impact on cancer prevention research," says Bernard Levin, M.D., M. D. Anderson's vice president for cancer prevention and population sciences. "She has made remarkable advances in the field of molecular and genetic epidemiology that have greatly enhanced our existing knowledge." Her research has contributed to a better understanding of susceptibility to various types of cancer and response to therapy, with the long-term goals of identifying high-risk subgroups who can benefit from intensive cancer screening, creating genetic profiles for use in individualizing therapy and understanding the functional consequences of chemoprevention, chemotherapy or radiotherapy response. Spitz' current research includes: * Finding more predictive genetic markers for lung cancer risk in smokers and those who have never smoked * Evaluating genetic markers of nicotine addiction * Developing new functional assays of DNA repair capacity to help predict lung cancer risk in current and former smokers * Identifying molecular predictors of response to therapy, toxicity and patient survival * Developing quantitative methods for accurate risk classification, using combinations of risk factors and genetic variations While at M. D. Anderson, Spitz has received multiple awards, including the Julie and Ben Rogers Award for Excellence in Cancer Prevention, the Mesa Petroleum Company Professorship in Cancer Prevention, the Faculty Achievement Award in Cancer Prevention and the Texas Business and Professional Women Award. Additional honors include the Distinguished Achievement Award from the American Society of Preventive Oncology, the Award for Research Excellence in Epidemiology or Prevention from the American Association of Cancer Research and the American Cancer Society, the Rosalind Franklin Science Award for Women in Science from the National Cancer Institute and the Dr. William Cahan Distinguished Professor Award from the Flight Attendants Medical Research Institute. Spitz joined M. D. Anderson in 1981, becoming the first permanent chair of the Department of Epidemiology in May 1995. She earned her medical degree from the University of Witwatersrand Medical School in Johannesburg, South Africa, and her master's of public health degree from The University of Texas School of Public Health, where she currently holds an academic appointment, as well as at The University of Texas Graduate School of Biomedical Sciences. http://dx.doi.org/10.4161/cbt.3.11.1320 http://www.landesbioscience.com/journals/cbt/article/1320/ article News 1538-4047 Riku Koivusalo and Sakari Hietanen cbt The cytotoxicity of chemotherapy drugs varies in cervical cancer cells depending on the p53 status Landes Bioscience 2004-10-15 1177 - 1183 Cancer Biology & Therapy 3-11 Landes Bioscience Metastatic cervical cancer remains a clinical problem. The development of more efficient treatment modalities and the optimal use of chemo- and radiotherapy require better understanding of their impact on regulation of cell survival and apoptosis, but the issue is insufficiently explored. Human papillomavirus (HPV) E6 protein is present in nearly all cervical cancers, targeting the p53 tumor suppressor protein for degradation. We studied the role of p53 in mediating the cytotoxic effects of 31 chemotherapy compounds. SiHa cervical cancer cells, carrying wild type (wt) p53 and HPV16 genome, were stably transfected with dominant negative p53 (DDp53) or ectopic HPV16 E6 in order to inhibit p53 function. The effects of chemotherapy drugs in these cells were compared to the effects in cells retaining endogenous residual p53 activity. 28 out of 31 drugs reduced the amount of E6 mRNA, but only some induced marked p53 activation. In clonogenic cell survival experiments, the presence of DDp53 and ectopic E6 either increased or decreased cytotoxicity, depending on the drug. The decrease of E6 mRNA was necessary, but not sufficient event in the p53 activation by chemotherapy. The impact of p53 on clonogenic cell survival varied between 0- 60%, indicating that p53 plays an important, but not crucial role in response to chemotherapy. The finding that chemosensitivity varies depending on the p53 status may have clinical implications, since early stage cervical cancer cells usually carry wt p53, whereas p53 mutations are frequently found in advanced disease. http://dx.doi.org/10.4161/cbt.3.11.1340 http://www.landesbioscience.com/journals/cbt/article/1340/ article Research Paper 1538-4047 cbt Cover Image Landes Bioscience 2004-10-15 Cancer Biology & Therapy 3-11 Landes Bioscience The cover demonstrates immunohistochemical labeling of inhibin-β A overexpression (brown color) in pancreatic adenocarcinoma cells, but not in adjacent normal stroma and epithelium. Inhibin-β A is one of many genes found by Dengfeng Cao and colleagues using bioinformatics analyses of ESTs overexpressed in pancreatic adenocarcinomas. This study demonstrates that bioinformatics tools can be used to characterize differentially overexpressed ESTs, and that some of these ESTs may be diagnostically and therapeutically useful targets that might be missed using data from currently annotated databases. http://dx.doi.org/10.4161/cbt.3.11.1365 http://www.landesbioscience.com/journals/cbt/article/1365/ article Editor's Corner 1538-4047 Shao-Chun Wang and Mien-Chie Hung cbt Finding the bEST routes to cancer Landes Bioscience 2004-10-15 1090 - 1091 Cancer Biology & Therapy 3-11 Landes Bioscience Commentary to: Identification of Novel Highly Expressed Genes in Pancreatic Ductal Adenocarcinomas through a Bioinformatics Analysis of Expressed Sequence Tags Dengfeng Cao, Steven R. Hustinx, Guoping Sui, P. Bala, Norihiro Sato, Sean Martin, Anirban Maitra, Kathleen M. Murphy, John L. Cameron, Charles J. Yeo, Scott E. Kern, Michael Goggins, Akhilesh Pandey and Ralph H. Hruban http://dx.doi.org/10.4161/cbt.3.11.1403 http://www.landesbioscience.com/journals/cbt/article/1403/ article Commentary