Table of Contents

Volume 7, Issue 1

  January 2008

  Pages 3 - 153

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EDITOR'S CORNER

Open Access Article

Cover Image



http://dx.doi.org/10.4161/cbt.7.1.5515
Abstract | PDF

Even early stage ovarian cancer may show a significant number of positive lymph nodes, suggesting that metastasis plays a major role in the abysmal five-year survival rates for this disease. Better chemotherapeutic options are necessary to increase the survival rate for this disease. This month’s cover shows the expression of MUC1 in ovarian cancer tissues. In this issue of Cancer Biology & Therapy, Song and colleagues target MUC1 expressing ovarian cancer cells with a Bismuth-213 tagged Anti- MUC1 monoclonal antibody and show that one injection of the agent can prolong survival by 25 days in mice. Additional details can be found in the article by Song and colleagues.




REVIEW

Open Access Article

Biology of breast cancer bone metastasis

Mojtaba Akhtari, Junaid Mansuri, Kam A. Newman, Theresa M. Guise and Prem Seth
Pages 3 - 9
http://dx.doi.org/10.4161/cbt.7.1.5163
Abstract | PDF

Breast carcinoma ranks among the most prevalent malignancies in women. Breast carcinoma frequently metastasizes to bone and approximately 70% of patients with breast cancer have bone metastases, which generally are osteolytic lesions. They cause major morbidity and mortality in patients; and the available treatment options are limited. Bone-specific homing and colonization of cancer cells are important and interesting features of metastasis. There are complex and multiple steps in the process of bone metastasis; and the elaborate interaction between breast carcinoma and bone involves various cytokines, growth factors and cellular signals, which results in a vicious cycle and promotes tumor cell accumulation and osteolysis. Recent advances in molecular biology have resulted in major breakthroughs in our understanding of the pathogenesis of bone metastasis in breast cancer, which is critical in preventing metastasis, designing novel and targeted treatments and prolonging survival in this devastating condition.




JOURNAL CLUB

Open Access Article

HIF-1α and STAT3 client proteins interacting with the cancer chaperone Hsp90: Therapeutic considerations

Hanna Leah Kim, Marco Cassone, Laszlo Otvos Jr. and Paraskevi Vogiatzi
Pages 10 - 14
http://dx.doi.org/10.4161/cbt.7.1.5458
Abstract | PDF

Heat shock protein 90 (Hsp90) is an ATP-dependent chaperone and a noteworthy component of cellular folding machinery in eukaryotes and bacteria. What makes Hsp90 specifically promising as a target for anti-cancer drugs is that many of its client proteins are involved in signaling and chromatin-remodeling pathways, and these pathways are often disrupted in many types of cancers. A very recent study by Lang et al. (Clin Cancer Res 2007; 13:6459-68) provide compelling evidence supporting a novel IL-6/STAT3/ HIF-1α autocrine loop in pancreatic cancer cells, emphasizing the arresting role of Hsp90 inhibitors. Here we discuss up-to-date advances towards the development of novel Hsp90 inhibitors designed to selectively block the growth and proliferation of tumor cells and proving to be intriguing targets for current clinical studies and cancer therapeutics.




CLINICAL STUDY

Open Access Article

Circulating biomarkers of bevacizumab activity in patients with breast cancer

Neelima Denduluri, Sherry X. Yang, Arlene W. Berman, Diana Nguyen, David J. Liewehr, Seth M. Steinberg and Sandra M. Swain
Pages 15 - 20
http://dx.doi.org/10.4161/cbt.7.1.5337
Abstract | PDF

Purpose: Noninvasive markers of anti-vascular endothelial growth factor (VEGF) therapy are needed. Soluble vascular cell adhesion molecule (sVCAM-1), soluble VEGF receptor-2 (sVEGFR-2), and plasma VEGF levels were assessed as potential biomarkers of therapy with bevacizumab. Tumor samples were evaluated for VEGFR-2 mutations before and after bevacizumab. Experimental Design: Twenty-one patients with breast cancer underwent neoadjuvant treatment with bevacizumab for 1 cycle followed by 6 cycles of bevacizumab, chemotherapy, and filgrastim. Peripheral blood samples were collected at baseline, post cycles 1, 4 and 7. sVCAM-1, VEGF and sVEGFR-2 levels were measured by enzyme-linked immunosorbent assay (ELISA). Exons 17-26 of VEGFR-2 were sequenced on tissue samples from 20 patients at baseline and post cycle 1 to evaluate for tumor mutations. Results: From baseline to post cycle 1, sVCAM-1 and sVEGFR-2 values increased by a median of 180.5 ng/ml (p<0.0001) and 1927 ng/ml respectively (p = 0.0003). Baseline VEGF, sVEGFR-2, and sVCAM-1 levels nor changes in sVEGFR-2 and sVCAM-1 levels were associated with clinical response. Median baseline sVEGFR-2 levels were 11322 ng/ml and 7524 ng/ml in patients with (n=5) and without (n=6) wound healing problems respectively, (p=0.052). In 40 samples where tumor VEGFR-2 sequencing was obtained, no mutations were seen compared to the reference sequence. Conclusions: sVCAM-1 and sVEGFR-2 values increased significantly after treatment with bevacizumab, possibly due to compensatory mechanisms secondary to VEGF inhibition. sVEGFR-2 levels were somewhat higher in patients with wound healing problems and may potentially predict patients at higher risk of this complication. There were no tumor VEGFR-2 mutations.




COMMENTARY

Open Access Article

Biomarkers in breast cancer

Heather McArthur and Maura Dickler
Pages 21 - 22
http://dx.doi.org/10.4161/cbt.7.1.5590
Abstract | PDF

Commentary to:

Circulating Biomarkers of Bevacizumab Activity in Patients with Breast Cancer

Neelima Denduluri, Sherry X. Yang, Arlene W. Berman, Diana Nguyen, David J. Liewehr, Seth M. Steinberg, Sandra M. Swain




RESEARCH PAPERS

Open Access Article

Genetic polymorphisms in OGG1 and their association with angiomyolipoma, a benign kidney tumor in patients with tuberous sclerosis

Samy L. Habib, Elaine Danial, Subrata Nath, Jennifer Schneider, Christopher P. Jenkinson, Ravindranath Duggirala, Hanna E. Abboud and Farook Thameem
Pages 23 - 27
http://dx.doi.org/10.4161/cbt.7.1.5120
Abstract | PDF

The enzyme 8-oxoguanine glycosylase 1 (OGG1) repairs 8-oxo-2- deoxyguanosine residue (8-oxodG) an oxidatively damaged promutagenic base. Genetic variations in OGG1 gene have been shown to modulate DNA repair capacity and are related risk of tumor development. However, epidemiologic findings have been inconsistent. The purpose of this study is to determine whether genetic variants in OGG1 play a role in susceptibility to angiomyolipoma, a benign kidney tumor associated with tuberous sclerosis complex (TSC) patients. To identify genetic variations, all 7 exons of the OGG1 gene were amplified by PCR and sequenced in 22 TSC patients with angiomyolipoma (cases) and 18 controls. By direct sequencing, we identified four missense mutations in OGG1: Arg(45)Gln, Ala(85)Ser, Arg(229)Gln, and Ser(326)Cys. Genotypic association with angiomyolipoma was performed using the measured genotype approach as implemented in the variance component analytical tools. Association analysis showed the presence of significant association (p=0.01) only between the Ser(326)Cys polymorphism of OGG1 and angiomyolipoma. We also assessed the presence of oxidative DNA damage in kidney section from normal healthy subjects, normal kidney tissue from TSC patients and kidney angiomyolipoma tissue from TSC patients by immunostaining for 8-oxodG. 8-OxodG staining was highly abundant in kidney angiomyolipoma tissue from TSC patients compared to weak staining in uninvolved tissue from the same TSC patients or normal kidney from healthy subjects. Taken together, our findings suggest that Ser(326)Cys variant of OGG1 may confer risk for development of angiomyolipomas by increasing oxidative DNA damage.

Open Access Article

The role of histamine in human mammary carcinogenesis: H3 and H4 receptors as potential therapeutic targets for breast cancer treatment.

Vanina Medina, Máximo Croci, Ernesto Crescenti, Nora Mohamad, Francisca Sanchez-Jiménez, Noelia Massari, Mariel Nuñez, Graciela Cricco, Gabriela Martin, Rosa Bergoc and Elena S. Rivera
Pages 28 - 35
http://dx.doi.org/10.4161/cbt.7.1.5123
Abstract | PDF

There is increasing evidence that describes a histamine role in normal and cancer cell proliferation. To better understand the importance of histamine in breast cancer development, the expression of histamine H3 (H3R) and H4 (H4R) receptors and their association with proliferating cell nuclear antigen (PCNA), histidine decarboxylase (HDC) and histamine content were explored in mammary biopsies. Additionally, we investigated whether H3R and H4R were implicated in the biological responses triggered by histamine in MDA-MB-231 breast cancer cells. The expression levels of H3R, H4R, PCNA, HDC and histamine content were determined by immunohistochemistry in 40 benign and malignant lesions. MDA-MB-231 cells proliferation (clonogenic assay and BrdU incorporation) and cell cycle distribution (flow cytometry) were evaluated upon treatment with histamine, H3R and H4R agonists and antagonists. Apoptosis was determined by Annexin staining and TUNEL assay. Cell migration was assessed by transwell system. Results indicate that H3R was detected in 67% (10/15) of benign lesions and in almost all carcinomas (24/25), being the level of its expression significantly higher in carcinomas (P=0.0016). The non-tumoral breast tissue surrounding carcinomas revealed a lower H3R expression compared to the tumor cells. Only 13% (2/15) of the benign lesions expressed H4R compared to 44% (11/25) of the carcinomas. Interestingly, H3R expression was correlated in carcinomas with the expression of HDC and PCNA (P<0.0001), and also histamine content (P=0.0229). Accordingly, histamine increased MDA-MB-231 cells proliferation and also migration via H3R. In contrast, activation of H4R inhibited proliferation and this effect was associated with an arrest in the G0/G1 phase of the cell cycle and an induction of apoptosis. Present findings demonstrate the presence of H3R and H4R in human mammary tissue and suggest that H3R may be involved in the regulation of breast cancer growth and progression representing a novel molecular target for new therapeutic approach.




COMMENTARY

Open Access Article

Histamine in cancer: The dual faces of the coin

Fabio Cianchi, Maria Cristina Vinci and Emanuela Masini
Pages 36 - 37
http://dx.doi.org/10.4161/cbt.7.1.5706
Abstract | PDF

Commentary to:

The role of histamine in human mammary carcinogenesis: H3 and H4 receptors as potential therapeutic targets for breast cancer treatment.

Vanina Medina, Máximo Croci, Ernesto Crescenti, Nora Mohamad, Francisca Sanchez-Jiménez, Noelia Massari, Mariel Nuñez, Graciela Cricco, Gabriela Martin, Rosa Bergoc, Elena Rivera




RESEARCH PAPERS

Open Access Article

MDM2 displays differential activities dependent upon the activation status of NFκB

Misty D. Cheney, Pamela P. McKenzie, Erin L. Volk, Liying Fan and Linda C. Harris
Pages 38 - 44
http://dx.doi.org/10.4161/cbt.7.1.5125
Abstract | PDF

MDM2 is an oncoprotein best characterized for its role in the inactivation and degradation of the p53 tumor suppressor. However, MDM2 has many other binding partners and its p53-independent role in the regulation of cell growth and survival appears to be extremely complex. This report describes the expression of MDM2 in two rhabdomyosarcoma cell lines, both expressing a mutant p53 gene. Expression of MDM2 in Rh30 cells enhanced cell growth whereas expression of MDM2 in RD cells suppressed their growth and enhanced the rate of spontaneous apoptosis. The mechanism for these opposite phenotypes was demonstrated to be due to differential effects on the NFκB pathway. Previously MDM2 has been shown to activate NFκB through activation of transcription of the p65RelA subunit. In Rh30 cells MDM2 acted similarly to previously described thereby promoting growth of Rh30 cells. In untreated RD cells p65RelA was constitutively overexpressed resulting in activation of the NFκB pathway. Expression of MDM2 in RD cells transcriptionally repressed p65RelA and suppressed NFκB activity, resulting in a reduced growth rate and enhanced apoptosis. The MDM2-sensitive region of the p65 promoter was localized to a 225bp fragment to which MDM2 protein was shown to bind. The observation that MDM2 induces apoptosis under certain circumstances may help to explain the apparently surprising clinical studies that have shown that MDM2 expression in tumors is often associated with a favorable prognosis.

Open Access Article

Expression and significance of HERG protein in gastric cancer

Xiao-Dong Shao, Kai-Chun Wu, Xiao-Zhong Guo, Man-Jiang Xie, Jing Zhang and Dai-Ming Fan
Pages 45 - 50
http://dx.doi.org/10.4161/cbt.7.1.5126
Abstract | PDF

Objectives: Our previous studies showed that delayed rectifier potassium currents existed in human gastric cancer cells and the currents were related to the growth of gastric cancer cells. Human ether-a-go-go-related gene (herg) encoding α subunit of delayed rectifier potassium channel has been indicated with involvement in tumor cell growth and death. The purpose of the present study is to investigate the expression of HERG protein in gastric cancer tissue and cells; analyze the relationship between the expression of HERG protein and the clinicopathological characteristics of patients with gastric cancer; explore the effects of HERG protein on biological behaviours of gastric cancer cells. Methods: The expression of HERG protein in gastric cancer tissues and cells was measured by immunohistochemistry and Western blot, respectively. Reduction of HERG protein was carried out by siRNA technology. The proliferation, ability of clone formation, cell cycle, apoptosis and invasive ability of gastric cancer cells were evaluated by MTT assay, clone formation assay, flow cytometry, cell invasion assay and transmission electron microscopy. Tumor growth in nude mice was to be used to access the tumorigenicity of gastric cancer cells and HERG currents were recorded by patch-clamp. Results: HERG protein was exclusively expressed in gastric cancer cells. The expression of HERG protein was associated with tumor differentiation, TNM stage and lymph node involvement of gastric cancer. Silencing HERG protein could eliminate the HERG currents and inhibit proliferation, clone formation, invasiveness and tumorigenicity of gastric cancer cells. Reducing HERG protein could also inhibit gastric cancer cells entering S phase from G1 phase and induce apoptosis of gastric cancer cells. Conclusion: HERG protein is involved in carcinogenesis of gastric cancer and is a potential therapeutic target of gastric cancer.

Open Access Article

Synergistic cytotoxicity of Bcl-xL inhibitor, gossypol and chemotherapeutic agents in non-Hodgkin’s lymphoma cells

Zhi-Ming Li, Wen-Qi Jiang, Zhen-Yu Zhu, Xiao-Feng Zhu, Jun-Min Zhou, Zong-Chao Liu, Da-Jun Yang and Zhong-Zhen Guan
Pages 51 - 60
http://dx.doi.org/10.4161/cbt.7.1.5128
Abstract | PDF

Anti-apoptotic proteins Bcl-2 and Bcl-xL are overexpressed in 80% of non-Hodgkin’s lymphoma cells and are thought to play an important role in the resistance of lymphoma cells to current chemotherapeutic agents. Gossypol, an orally-active polyphenolic aldehyde derived from the cotton plant, has been known to have potential anti-neoplastic activity. Recently, gossypol was found to bind to the BH3 binding groove of Bcl-xL and with lesser affinity to Bcl-2. The present study was conducted to determine whether gossypol increases the sensitivity of non-Hodgkin’s lymphoma cells to the actions of chemotherapeutic agents by potentiating treatment-induced apoptosis. The interactions observed between gossypol and chemotherapeutic drugs were analyzed using the median effect principle (CalcuSyn analysis). Our data showed that treatment of Ramos cells with gossypol not only induced cell arrest on the G0/G1 phase, but also augmented apoptosis and growth inhibition induced by etoposide (VP-16), doxorubicin hydrochloride (ADM), vincristine (VCR), and paclitaxel (taxol). However, when gossypol was combined with cisplatin (DDP) an antagonistic effect was observed. Gossypol-induced cell cycle arrest was accompanied by decreased expression of cyclin D1 in Ramos cells. In addition, the peroxisome proliferator-activated receptor (PARP) pathway is, at least in part, involved in the gossypol-induced apoptosis when combined with VP-16. These data indicate that single-agent gossypol is effective in inhibiting growth of non-Hodgkin’s lymphoma cells in vitro and combination studies with certain secondary chemotherapeutic agents further demonstrate it’s synergistic cytotoxicity. These findings support future preclinical and clinical studies of gossypol in the treatment of non-Hodgkin’s lymphoma.




COMMENTARY

Open Access Article

Targeting Bcl-xL enhances the cytotoxicity of chemotherapeutics

Shulin Wang
Pages 61 - 62
http://dx.doi.org/10.4161/cbt.7.1.5571
Abstract | PDF

Commentary to:

Synergistic cytotoxicity of Bcl-xL inhibitor, gossypol and chemotherapeutic agents in non-Hodgkin’s lymphoma cells

Zhi-Ming Li, Wen-Qi Jiang, Zhen-Yu Zhu, Xiao-Feng Zhu, Jun-Min Zhou, Zong-Chao Liu, Da-Jun Yang and Zhong-Zhen Guan




RESEARCH PAPERS

Open Access Article

The role of p53 in the trafficking of copper-64 to tumor cell nuclei

Martin Eiblmaier, Laura A. Meyer and Carolyn J. Anderson
Pages 63 - 69
http://dx.doi.org/10.4161/cbt.7.1.5130
Abstract | PDF

Copper-64 (T1/2 = 12.7 h; β+: 17.8%, β-: 41%) has applications in both positron emission tomography (PET) imaging and targeted radiotherapy of cancer. Copper-64 radiopharmaceuticals have shown tumor growth inhibition with a relatively low radiation dose in animal models; however, the mechanism of cytotoxicity has not been fully elucidated. Here, we report an investigation on the potential role of the tumor suppressor protein p53 in trafficking 64Cu to tumor cell nuclei. Two EGFR expressing human colorectal cell lines (HCT 116 +/+ and HCT 116 -/-) that are positive or negative for p53 expression respectively, were used to compare internalization and nuclear localization of [64Cu]copper acetate and of 64Cu-DOTA-cetuximab, a monoclonal anti-EGFR antibody. [64Cu]copper acetate uptake into cells was similar between the two cell lines during a 24 h time course. In contrast, the uptake of [64Cu]copper acetate in the nuclei of HCT 116 +/+ cells was significantly higher than in HCT 116 -/- cells (p < 0.0001) at 24 h. There was no difference in receptor binding, receptor-mediated internalization, and efflux of 64Cu-DOTA-cetuximab between the two HCT 116 cells lines. However, nuclear localization of 64Cu-DOTA-cetuximab showed increased uptake in the nuclei of HCT 116 +/+ cells as early as 4 h. These data demonstrate that 64Cu is delivered to tumor cell nuclei in a p53 positive cell line in significantly greater amounts than in p53 negative cells by both non-specific and receptor-mediated uptake mechanisms.

Open Access Article

Downregulation of IgG Fc binding protein (FcγBP) in prostate cancer

Mozammel H. Gazi, MeiLan He, John C. Cheville and Charles Y.F. Young
Pages 70 - 75
http://dx.doi.org/10.4161/cbt.7.1.5131
Abstract | PDF

By means of protein expression profile, mass spectral and/or RT-PCR analyses we found for the first time IgG Fc binding protein (FcγBP), distinct from Fcγ receptors is expressed in both human and mouse prostates. There is a strong correlation between downregulation of FcγBP and the progression of prostate cancer in Transgenic Adenocarcinoma Mouse Prostate (TRAMP) mice. FcγBP gene expression is significantly reduced or lost in human prostate tumor tissues and prostate cell lines. The differentially expressed FcγBP could reflect its potential role in prostate malignancy as well as an indicator for progression of the cancer.

Open Access Article

Bismuth-213 radioimmunotherapy with C595 anti–MUC1 monoclonal antibody in an ovarian cancer ascites model

Emma Y. Song, Chang F Qu, Syed M.A. Rizvi, Chand Raja, Julia Beretov, Alfred Morgenstern, Christos Apostolidis, Frank Bruchertseifer, Alan Perkins and Barry J Allen
Pages 76 - 80
http://dx.doi.org/10.4161/cbt.7.1.5132
Abstract | PDF

Purpose: Control of ovarian cancer (OC) ascites remains a major objective in post-surgical treatment. The aim of this study was to investigate the effect of targeted alpha therapy (TAT) for the control of ascites in an OC ascites mouse model; the biodistribution of 213Bi-C595 and its long term toxicity. Methods: The expression of tumor-associated antigen mucin-1 (MUC-1) in OVCAR3 ascites cells in mice and OC cancer tissues in patients was detected by indirect immmunostaining. The monoclonal antibody (MAb) C595 was labeled with 213Bi using the chelator cDTPA to form the alpha-immunoconjugate (AIC). Mice were injected with different concentrations of AIC by i.p administration. Changes in tumor progression were assessed by measurement of the circumference of the abdomen. Results: MUC-1 is strongly expressed in 73% of OC tissues. At 9 days post-cell inoculation in mice, a single injection of 355 MBq/kg of 213Bi-C595 can prolong survival by 25 days. A high tumor: blood ratio (5.8) was found in biodistribution study. The maximum tolerance dose (MTD) was more than 1180 MBq/kg up to 21 weeks. Conclusions: C595 is a specific targeting vector for ovarian cancer cells, which show a high percentage of expression of MUC1. 213Bi-C595 can effectively target and kill ovarian cancer cells in vitro and in vivo. 213Bi-C595 is the recommended alpha conjugate for a Phase I clinical trial for ovarian cancer.




COMMENTARY

Open Access Article

Targeting the human MUC1 oncoprotein: A tale of two proteins

Donald W. Kufe
Pages 81 - 84
http://dx.doi.org/10.4161/cbt.7.1.5631
Abstract | PDF

Commentary to:

Bismuth-213 radioimmunotherapy with C595 anti–MUC1 monoclonal antibody in an ovarian cancer ascites model

Emma Y. Song, Chang F Qu, Syed M.A. Rizvi, Chand Raja, Julia Beretov, Alfred Morgenstern, Christos Apostolidis, Frank Bruchertseifer, Alan Perkins




RESEARCH PAPERS

Open Access Article

Modulation in the activity of lactate dehydrogenase and level of c-Myc and c-Fos by modified base queuine in cancer

Chandramani Pathak, Yogesh K. Jaiswal and Manjula Vinayak
Pages 85 - 91
http://dx.doi.org/10.4161/cbt.7.1.5133
Abstract | PDF

Cancer is characterized by uncontrolled cell growth, which results from unlimited proliferation and disturbs various cellular activities. Queuine is a highly modified base analogue of guanine found at first anti-codon position of specific tRNAs i.e. tRNATyr, tRNAHis, tRNAAsp and tRNAAsn. These tRNAs are known as Q-family of tRNA. The tRNAs of Q-family are completely modified to Q-tRNAs in terminally differentiated somatic cells, however hypomodification of Q-tRNA is closely associated with cell proliferation and malignancy. Queuosine modification of tRNAs may be essential for normal development, differentiation and cellular functions. Physiological role of queuine remains ill defined but direct or indirect evidences suggest that queuine or Q-tRNA participates in many cellular functions such as regulation of cell proliferation, control of glycolytic metabolism, alteration in expression of proto-oncogenes, modulation of signal transduction pathways but the mechanism is not well known. Increase in LDH-A expression regulated by c-myc is well documented in a variety of tumor cells. Over expression of proto-oncogenes cause deregulated cellular responses which may lead to development of cancer. The cellular proto-oncogenes like c-myc and c-fos have important role in cell growth, proliferation and differentiation. The present study is aimed to investigate queuine mediated modulation in the activity of lactate dehydrogenase and expression of proto-oncogenes like c-myc and c-fos in T-cell lymphoma (DLAT) induced cancerous mouse. The results indicate that elevated lactate dehydrogenase activity is brought down by queuine treatments and the elevated levels of c-myc and c-fos in DLAT cancerous mouse are down regulated, suggesting that queuine inhibits anaerobic metabolism and cell proliferation.

Open Access Article

The effectiveness of retinoic acid treatment in bladder cancer: Impact on recurrence, survival and TGFα and VEGF as end-point biomarkers.

Diaa A. Hameed and Tarek H. El-Metwally
Pages 92 - 100
http://dx.doi.org/10.4161/cbt.7.1.5134
Abstract | PDF

Introduction and Aims: Being best-studied superficial bladder cancer (SBC) chemopreventives, retinoids’ negative studies and toxicity were stumbling. With proper understanding of retinoid metabolism, we aimed at investigating combined ketoconazole (a strong inhibitor of retinoic acid-catabolizing cytochrome P450s)-all-trans retinoic acid (Keto-atRA) SBC treatment. VEGF and TGF-α levels are end-point pathogenetic biomarkers involved in early SBC. Material and Methods: Seven days after TURT visible tumor(s), combined atRA 1 mg/kg for 5 days/week + Keto 200 mg twice daily for 5 days/week for 3 months were given to 16 patients with SBC stages Ta and T1 with various grades. 3 months follow up/20 months used white light cystoscopy and urinary cytology. Recurrence rate and survival time were compared to a retrospective group of 25 patients of comparable age, stage and grade with TURT as sole treatment for SBC. VEGF and TGF-α were measured in urine and serum of 12 normal subjects and treated patients. Samples were collected just before TURT, 1 week after TURT, at the end of 1 month and at the end of 3 months of treatment. Results: Keto-atRA treatment significantly improved survival time and decreased recurrence rate compared to control disease group, with tolerable and reversible side-effects. Treatment normalized induced levels of VEGF and TGF-α with a positive correlation between these cytokines. Conclusions: The combination and schedule used for Keto-atRA therapy effectively reduced recurrence rate and increased survival time of SBC patients probably through reduction of VEGF and TGF-α as major mitogenic/angiogenic factors; possibly by eliminating malignant cells that produce them.




COMMENTARY

Open Access Article

Prevention of bladder cancer recurrence by retinoic acid-ketoconazole: A promising strategy?

Yair Lotan and Rueben Lotan
Pages 101 - 102
http://dx.doi.org/10.4161/cbt.7.1.5860
Abstract | PDF

Commentary to:

The effectiveness of retinoic acid treatment in bladder cancer: Impact on recurrence, survival and TGFα and VEGF as end-point biomarkers

Diaa A. Hameed, Tarek H. El-Metwally




RESEARCH PAPER

Open Access Article

Development of Ad-mda7/IL-24-resistant lung cancer cell lines

Abujiang Pataer, Sunil Chada, Jack A. Roth, Kelly K. Hunt and Stephen G. Swisher
Pages 103 - 108
http://dx.doi.org/10.4161/cbt.7.1.5162
Abstract | PDF

Many cancers can become resistant to repeated administration of even the most effective therapeutic agents. In developing adenoviral mda-7/IL-24 (Ad-mda-7/IL-24) therapy for lung cancer, we have anticipated this potential clinical problem by attempting to identify the molecular mechanisms of Ad-mda7/IL-24 resistance in several Ad-mda7/IL-24-resistant lung cancer cell lines that we have developed. For the present study, we established four Ad-mda7-resistant cell lines by repeated selection of resistant clones of parental Ad-mda7-sensitive A549 cells: two lines (A549R1 and A549R2) resistant to both adenoviral vector and the mda-7 gene and two (A549R3 and A549R4) resistant to the therapeutic mda-7 gene only. As shown by western blot analysis of several known anti-apoptotic proteins, parental A549 and resistant A549R3 cells expressed similar levels of AKT and phosphorylated AKT (p-AKT), whereas resistant A549R3 and A549R4 cells expressed higher levels of bcl-2 and lower levels of bcl-xL than did their parental cells. As shown by flow-cytometric analysis, treating resistant A549R3 and A549R4 cells with a combination of Ad-mda7 and 17-allylamino-17-demethoxygeldanamycin (17AAG) (50 nM) for 48 hours enhanced apoptosis. Together, these in vitro findings indicate that an antiapoptotic mechanism may underlie Ad-mda7 resistance and that such resistance can be overcome by addition of 17AAG. Further investigations along these lines are warranted.




COMMENTARY

Open Access Article

Acquired and innate resistance to the cancer-specific apoptosis-inducing Cytokine, mda-7/IL-24: Not insurmountable therapeutic problems

Devanand Sarkar, Paul Dent, David T. Curiel and Paul B. Fisher
Pages 109 - 112
http://dx.doi.org/10.4161/cbt.7.1.5693
Abstract | PDF

Commentary to:

Development of Ad-mda7/IL-24-resistant Lung Cancer Cell Lines

Abujiang Pataer, Sunil Chada, Jack A. Roth, Kelly K. Hunt, Stephen G. Swisher




RESEARCH PAPERS

Open Access Article

Ciprofloxacin-induced G2 arrest and apoptosis in TK6 lymphoblastoid cells is not dependent on DNA double-strand break formation

Daniel J. Smart, H. Dorota Halicka, Frank Traganos, Zbigniew Darzynkiewicz and Gary M. Williams
Pages 113 - 119
http://dx.doi.org/10.4161/cbt.7.1.5136
Abstract | PDF

Drugs developed for the treatment of conditions other than neoplasia can also show promise as potential antitumor agents. The fluoroquinolone antibiotic ciprofloxacin (CPFX) is known to modulate cycle cell progression and apoptosis in cancer cells, and is thought to induce DNA double-strand breaks (DSBs) via topoisomerase II (topo II) inhibition and stabilized cleavage complex (SCC) formation. DSBs trigger Ser-139 phosphorylation of histone H2AX (γH2AX) by PI-3-like kinases including ATM; γH2AX can serve as a marker of DNA damage when measured in situ using immunocytochemistry and flow cytometry. The aim of the present study was to investigate the relationship between CPFX-mediated DNA damage and induction of apoptosis in human lymphoblastoid cells and phytohaemagglutinin (PHA)-stimulated lymphocytes (Lymphs). Treatment of TK6 cells (wild-type p53) with 100 μg/ml CPFX for 2-10 h produced no increase in γH2AX; to the contrary, its level in S phase cells was reduced at 10 h compared to controls. Nevertheless, stabilization of topo IIα, ATM Ser-1981 phosphorylation and G2 arrest was observed in TK6 cells exposed to CPFX for ≥4 h. However, following 24 h treatment, γH2AX was dramatically increased in a sub-population of cells indicating the onset of apoptosis (confirmed by presence of activated caspase 3). CPFX had a similar lack of effect on induction of γH2AX at early time points in WTK1 and NH32 cells (devoid of functional p53) and proliferating Lymphs, however, induction of apoptosis was less pronounced than in TK6 cells. Formation of SCC and activation of ATM (but lack of γH2AX induction) indicates topo II-mediated chromatin or DNA changes in the absence of DSBs; ATM activation apparently triggers the G2M checkpoint leading to G2 arrest. The subsequent induction of apoptosis appears to be facilitated by functional p53. CPFX may therefore have a potential use as a chemotherapeutic agent in the treatment of lymphoblast-derived cancer.

Open Access Article

hADA2a and hADA3 are required for acetylation, transcriptional activity and proliferative effects of beta-catenin

Min Yang, Marian L. Waterman and Rainer K. Brachmann
Pages 120 - 128
http://dx.doi.org/10.4161/cbt.7.1.5197
Abstract | PDF

Beta-catenin is the key transcriptional activator of the Wnt pathway important for development and tissue homeostasis of multicellular organisms. Its deregulation contributes to many human cancers. The beta-catenin transcriptional activator complex continues to be defined, but already contains several proteins with chromatin remodeling activity. Here we show that two members of histone acetyltransferase complexes without enzymatic activity, hADA2a and hADA3, are required for full activity of beta-catenin. hADA2a and hADA3 physically interact with beta-catenin, and the interaction is mediated through Armadillo repeats 6 through 12 and the C-terminal transactivation domain of beta-catenin. Both hADA2a and hADA3 reside with beta-catenin at the enhancer for the Wnt target gene c-Myc. RNA interference-mediated reduction of hADA2a and hADA3 results in reduced beta-catenin acetylation, reduced activity in reporter gene assays and reduced activation of endogenous beta-catenin target genes. Overall, loss of hADA2a and hADA3 negatively impacts beta-catenin-mediated proliferation. Our studies identify hADA2a and hADA3 as crucial cofactors of beta-catenin that are likely involved in the assembly of transactivation-competent beta-catenin complexes at Wnt target genes.




COMMENTARY

Open Access Article

hADA2a and hADA3: new players in ß-catenin signaling

Charles Lopez, Joshi Alumkal and Katy Van Hook
Pages 129 - 130
http://dx.doi.org/10.4161/cbt.7.1.5619
Abstract | PDF

Commentary to:

hADA2a and hADA3 are required for acetylation, transcriptional activity and proliferative effects of beta-catenin

Min Yang, Marian L. Waterman, Rainer K. Brachmann




RESEARCH PAPERS

Open Access Article

The effect of fatty acid-CoA ligase 4 on the growth of hepatic cancer cells

Chuangying Hu, Liang Chen, Yong Jiang, Yi Li and Shaofeng Wang
Pages 131 - 134
http://dx.doi.org/10.4161/cbt.7.1.5198
Abstract | PDF

In this study, we detected the expression of FACL4 mRNA in 40 patients with hepatic carcinoma and its adjacent normal tissues by semi-quantitative RT-PCR. The changes of proliferation and apoptosis of hepatic cancer cell line HepG2 with FACL4 protein expression were examined by MTT and flow cytometry respectively after FACL4 selective inhibitor triacsin C treatment. The activity related to apoptosis of proteinases, caspase-3, caspase-8 and caspase-9, were detected by colorimetry. The expression related to apoptosis of protein, wt-p53，Bax, and Bcl-2, in HepG2 cells were evaluated by S-P immunocytochemical dyeing. The results were: (1) FACL4 mRNA was expressed in 95.0% of hepatic cancer tissue, while the positive expression of FACL4 mRNA was 82.5% in cancer adjacent normal liver tissues. Moreover, there was a statistically significant increased in quantity of FACL4 mRNA in cancer tissues compared with adjacent normal liver tissues. (2) The concentration of triacsin C（0.5-2mg/L）could inhibit the proliferation and induce the apoptosis of HepG2 cells significantly in a dose- and time-effect. (3) During the apoptosis of HepG2 cells induced by triacsin C, flow cytometry coupled with Rhodamine 123 dyeing showed that mitochiondrial transmembrane potential of HepG2 declined significantly，and the activity of caspase-9 and caspase-3 increased more remarkably than caspase-8. Besides, the increased apoptosis was accompanied by increased Bax, and decreased wt-p53 and Bcl-2 protein levels. The present study suggested that FACL4 might play a role in the growth of hepatic cancer cells. FACL4 selective inhibitor triacsin C leads to a marked growth inhibition of human liver tumor cells, based on the inhibition of proliferation and induction of apoptosis. The apoptotic process was mediated by intrinsic mitochondrial apoptotic pathway due to activation of caspase-9 and caspase-3. The increased apoptosis was accompanied by upregulation of Bax, and decreased wt-p53 and Bcl-2 protein level.

Open Access Article

Allele-specific expression in the germline of patients with familial pancreatic cancer: An unbiased approach to cancer gene discovery

Aik Choon Tan, Jian-Bing Fan, Collins Karikari, Marina Bibikova, Eliza Wickham Garcia, Lixin Zhou, David Barker, David Serre, Georg Feldmann, Ralph H. Hruban, Alison P. Klein, Michael Goggins, Fergus J. Couch, Thomas J. Hudson, Raimond L. Winslow, Anirban Maitra and Aravinda Chakravarti
Pages 135 - 144
http://dx.doi.org/10.4161/cbt.7.1.5199
Abstract | PDF

Physiologic allele-specific expression (ASE) in germline tissues occurs during random X-chromosome inactivation1 and in genomic imprinting2, wherein the two alleles of a gene in a heterozygous individual are not expressed equally. Recent studies have confirmed the existence of ASE in apparently non-imprinted autosomal genes3-14; however, the extent of ASE in the human genome is unknown. We explored ASE in lymphoblastoid cell lines of 145 individuals using an oligonucleotide array based assay. ASE of autosomal genes was found to be a very common phenomenon in ~20% of heterozygotes at 78% of SNPs at 84% of the genes examined. Comparison of 100 affected individuals from familial pancreatic cancer kindreds and 45 controls revealed three types of changes in the germline: (a) loss of ASE, (b) gain of ASE, and, (c) rare instances of “extreme” (near monoallelic) ASE. The latter changes identified heterozygous deleterious mutations in a subset of these genes. Consequently, an ASE assay efficiently identifies candidate disease genes with altered germline expression properties as compared to controls, and provides insights into mechanisms that confer an inherited disease risk for pancreatic cancer.

Open Access Article

Oral administration of attenuated S. typhimurium carrying shRNA-expressing vectors as a cancer therapeutic

Nan Yang, Xiangying Zhu, Lishan Chen, Shenghua Li and Daming Ren
Pages 145 - 151
http://dx.doi.org/10.4161/cbt.7.1.5195
Abstract | PDF

RNAi has been successfully applied in genomic research, and it also holds considerable promise as a therapeutic approach to suppress disease-causing gene expression. Here, we show that attenuated S. typhimurium were capable of delivering shRNA-expressing vectors to mammalian cells and inducing RNAi in vitro and in vivo. Upon oral administration, S.typhimurium carrying shRNA-expressing vectors targeting bcl2 induced significant gene silencing in murine melanoma cells that led to a remarkably delayed tumor growth and prolonged survival in the mouse model. These results suggest that bacteria mediated RNAi may be a new potent approach to the treatment of cancers.




COMMENTARY

Open Access Article

Salmonella typhimurium as a novel RNA interference vector for cancer gene therapy

Meenhard Herlyn and Devraj Basu
Pages 152 - 153
http://dx.doi.org/10.4161/cbt.7.1.5772
Abstract | PDF

Commentary to:

Oral administration of attenuated S. typhimurium carrying shRNA-expressing vectors as a cancer therapeutic

Nan Yang, Xiangying Zhu, Lishan Chen, Shenghua Li, Daming Ren