Table of Contents

Volume 10, Issue 5

  September 1, 2010

  Pages 407 - 527

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REVIEW

Open Access Article

Transitional research in bladder cancer: From molecular pathogenesis to useful tissue biomarkers

Christian Bolenz and Yair Lotan
Pages 407 - 415
http://dx.doi.org/10.4161/cbt.10.5.13022
Abstract | PDF

Current risk stratification using clinical and pathological parameters in patients with urothelial carcinoma of the bladder (UCB) is insufficient. Additional information on the tumor biology can be derived from molecular biomarkers assessed in surgical UCB specimens and the predictive accuracy of oncologic end points may be improved. Biomarkers may also be used to predict the response to novel multimodal therapeutic approaches. Insights from the molecular pathogenesis of UCB can help identify potential biomarkers. A variety of candidate markers for future clinical use have been identified. However, results from comprehensive validation trials and prospective studies are still lacking. This precludes an application of molecular biomarkers in clinical practice at the moment. In this article, we review a selection of tissue biomarkers that are linked to important steps in molecular pathogenesis of UCB. We focused on biomarkers already tested in patient populations with potential clinical utility.

 




CLINICAL STUDY

Open Access Article

EGFR expression variance in paired colorectal cancer primary and metastatic tumors

Nirit Yarom, Celia Marginean, Terence Moyana, Ivan Gorn-Hondermann , H. Chaim Birnboim, Horia Marginean, Rebecca C. Auer, Micheal Vickers, Timothy R. Asmis, Jean Maroun and Derek Jonker
Pages 416 - 421
http://dx.doi.org/10.4161/cbt.10.5.12610
Abstract | PDF

Background: Previous studies indicate that drugs targeting the Epidermal Growth Factor Receptor (EGFR) signaling pathways can induce objective responses, prolong time to progression and improve survival of patients with metastatic colorectal cancer (mCRC). EGFR expression in the primary tumour may not predict response to these agents and data is conflicting regarding the correlation of EGFR expression in the primary tumour with the metastatic site. In other tumour sites, the presence of EGFR mutations was associated with efficacy in a subset of patients.
Objectives: The goal of this study is to correlate tumour EGFR expression between primary and liver metastatic sites, and to assess the mutational status in the EGFR kinase domain.
Methods: This is a single center retrospective study of patients who underwent surgical resection of CRC, for whom paired paraffin-embedded tissue blocks of primary tumours and resected liver metastases were available. EGFR immunostaining and mutation analyses were preformed.
Results: Fifty eight paired colorectal primaries and metastases were available for analysis. EGFR was detectable in 96.6% of the primary samples and in 89.7% of the metastatic samples. Perfect concordance in the intensity score between the primary and the metastases was found in 46.5% of the cases. While individual pairs were poorly concordant for intensity, the proportion of primaries with intense staining was similar to the proportion with intense staining in the metastatic samples. Overall survival did not correlate with either EGFR expression in the primary tumour, or with EGFR expression in the metastasis. There were 2 cases with mutations in the EGFR kinase domain. Both mutations were found in exon21 C>T.
Conclusions: In this analysis, EGFR expression in the primary tumor site was not predictive of its level in the metastasis. EGFR expression levels in the primaries and in the metastases do not appear to be useful prognostic markers.




COMMENTARY

Open Access Article

Epidermal growth factor receptor revisited: Prognostic marker or target for therapy?

Rosalyn B. Irby
Pages 422 - 424
http://dx.doi.org/10.4161/cbt.10.5.13194
Abstract | PDF

Commentary to:

EGFR expression variance in paired colorectal cancer primary and metastatic tumors

Nirit Yarom, Celia Marginean, Terence Moyana, Ivan Gorn-Hondermann , Chaim Birnboim, Horia Marginean, Rebecca Auer, Micheal Vickers, Timothy Asmis, Jean Maroun and Derek Jonker




CLINICAL STUDY

Open Access Article

Extrapleural pneumonectomy, photodynamic therapy and intensity modulated radiation therapy for the treatment of malignant pleural mesothelioma

Kevin L. Du, Stefan Both, Josephy S. Friedberg, Ramesh Rengan, Stephen M. Hahn and Keith A. Cengel
Pages 425 - 429
http://dx.doi.org/10.4161/cbt.10.5.12616
Abstract | PDF

Intensity modulated radiation therapy (IMRT) has recently been proposed for the treatment of malignant pleural mesothelioma (MPM). Here, we describe our experience with a multimodality approach for the treatment of mesothelioma, incorporating extrapleural pneumonectomy, intraoperative photodynamic therapy and postoperative hemithoracic IMRT. From 2004-2007, we treated 11 MPM patients with hemithoracic IMRT, 7 of whom had undergone porfimer sodium-mediated PDT as an intraoperative adjuvant to surgical debulking.
The median radiation dose to the planning treatment volume (PTV) ranged from 45.4-54.5Gy. For the contralateral lung, V20 ranged from 1.4 - 28.5%, V5 from 42 - 100%, and MLD from 6.8 - 16.5Gy. In our series, 1 patient experienced respiratory failure secondary to radiation pneumonitis that did not require mechanical ventilation. Multimodality therapy combining surgery with increased doses of radiation using IMRT, and newer treatment modalities such as PDT, appears safe. Future prospective analysis will be needed to demonstrate efficacy of this approach in the treatment of malignant mesothelioma. Efforts to reduce lung toxicity and improve dose delivery are needed and provide the promise of improved local control and quality of life in a carefully chosen multidisciplinary approach.




BEDSIDE-TO-BENCH REPORT

Open Access Article

Werner syndrome as a hereditary risk factor for exocrine pancreatic cancer: Potential role of WRN in pancreatic tumorigenesis and patient-tailored therapy

Stephen G. Chun and Nelson S. Yee
Pages 430 - 437
http://dx.doi.org/10.4161/cbt.10.5.12763
Abstract | PDF

Advanced age is considered a risk factor of pancreatic cancer, but this relationship at the molecular and genetic level remains unclear. We present a clinical case series focusing on an association between pancreatic adenocarcinoma and Werner syndrome (WS) that is an autosomal recessive genetic disorder characterized by accelerated aging and cancer predisposition, and caused by loss-of-function mutations in the WS RecQ helicase gene (WRN). Although pancreatic adenocarcinoma mostly occurs in a sporadic fashion, a minority of cases occurs in the context of susceptible individuals with hereditary syndromes. While WS has not been previously recognized as a risk factor for developing malignant tumors of the exocrine pancreas, the clinicopathologic features of three reported patients suggest a contributory role of WRN deficiency in pancreatic carcinogenesis. Molecular genetic analyses support the role of WRN as a tumor suppressor gene, although recent evidence reveals that WRN can alternatively promote oncogenicity depending on the molecular context. Based upon the clinico-pathologic features of these patients and the role of WRN in experimental models, we propose that its loss-of-function predisposes the development of pancreatic adenocarcinoma through epigenetic silencing or loss-of-heterozygosity of WRN. To test this hypothesis, we are investigating the mechanistic role of WRN in pancreatic cancer models including a pancreatic adenocarcinoma cell line generated from a human with WS. These studies are expected to provide new insight into the relationship between aging and pancreatic tumorigenesis, and facilitate development of novel strategies for patient-tailored interventions in this deadly malignancy.




RESEARCH PAPERS

Open Access Article

Simultaneous optical coherence tomography and laser induced fluorescence imaging in rat model of ovarian carcinogenesis

Lida P. Hariri, Erica R. Liebmann, Samuel L. Marion, Patricia B. Hoyer, John R. Davis, Molly A. Brewer and Jennifer K. Barton
Pages 438 - 447
http://dx.doi.org/10.4161/cbt.10.5.12531
Abstract | PDF

Determining if an ovarian mass is benign or malignant is an ongoing clinical challenge. The development of reliable animal models provides means to evaluate new diagnostic tools to more accurately determine if an ovary has benign or malignant features. Although sex cord-stromal tumors (SCST) account for 0.1-0.5% of ovarian malignancies, they have similar appearances to more aggressive epithelial cancers and can serve as a prototype for developing better diagnostic methods for ovarian cancer. Optical coherence tomography (OCT) and laser-induced fluorescence (LIF) spectroscopy are non-destructive optical imaging modalities. OCT provides architectural cross-sectional images at near histological resolutions and LIF provides biochemical information. We utilize combined OCT-LIF to image ovaries in post-menopausal ovarian carcinogenesis rat models, evaluating normal cyclic, acyclic, and neoplastic ovaries. Eighty-three female Fisher rats were exposed to combinations of control sesame oil, 4-vinylcyclohexene diepoxide (VCD) to induce ovarian failure, and/or 7,12-dimethylbenz[a]anthracene (DMBA) to induce carcinogenesis. Three or five months post-treatment, 162 ovaries were harvested and imaged with OCT-LIF: 40 cyclic, 105 acyclic, and 17 SCST. OCT identified various follicle stages, corpora lutea (CL), CL remnants, epithelial invaginations/inclusions, and allowed for characterization of both cystic and solid SCST. Signal attenuation comparisons between CL and solid SCST revealed statistically significant increases in attenuation among CL. LIF characterized spectral differences in cyclic, acyclic, and neoplastic ovaries attributed to collagen, NADH/FAD, and hemoglobin absorption. We present combined OCT-LIF imaging in a rat ovarian carcinogenesis model, providing preliminary criteria for normal cyclic, acyclic, and SCST ovaries which support the potential of OCT-LIF for ovarian imaging.

Open Access Article

Low density lipoprotein receptor mediates anti-VEGF effect of lymphocyte T-derived microparticles in Lewis lung carcinoma cells

Chun Yang, Carmen Gagnon, Xin Hou and Pierre Hardy
Pages 448 - 456
http://dx.doi.org/10.4161/cbt.10.5.12533
Abstract | PDF

Nonstop proliferation and vigorous neovascularization are two prominent characteristics of cancer. Antiangiogenic therapy has emerged as an important modality in treatment of solid tumors. Our previous work demonstrated that microparticles derived from apoptotic T-lymphocytes (LMPs) not only reduced the viabilities of high-proliferating cells, but also exhibited potent anti-angiogenic effects through inhibition of the vascular endothelial growth factor (VEGF)/VEGF receptor 2 signalling pathway. In the present study, we extended these studies to explore the anticancer potential of LMPs using a murine model of Lewis lung carcinoma (LLC). Results show that intratumoral injection of LMPs (2.5 mg/kg) decreased tumor size by more than 50% relative to control. Tumor microvessel density and VEGF-A levels were also markedly reduced upon LMPs treatment. To elucidate the underlying mechanisms of LMPs mediated antitumor activity, LLC cells were utilized in in vitro experiments. LMPs suppressed VEGF-A protein levels in LLC cells and led to inhibition of LLC cell viability and proliferation. In addition, knockdown of the low density lipoprotein receptor (LDLR) expression reduced the uptake of LMPs into LLC cells and attenuated the inhibitory effects of LMPs on cell growth and VEGF-A expression. Our findings demonstrate that LMPs exert antiangiogenic and proapoptotic effects that lead to inhibition of lung carcinoma by reducing VEGF-A levels, and LDLR mediates the anti-VEGF effect of LMPs through translocating LMPs into LLC cells. These results suggest that LMPs are promising anti-angiogenic therapeutic agent and represent a new therapeutic strategy for treating lung carcinomas.

Open Access Article

New insights into cathepsin D in mammary tissue development and remodeling

Naira V. Margaryan, Dawn A. Kirschmann, Alina Lipavsky, Caleb M. Bailey, Mary J. C. Hendrix and Zhila Khalkhali-Ellis
Pages 457 - 466
http://dx.doi.org/10.4161/cbt.10.5.12534
Abstract | PDF

Cathepsin D (CatD) is a lysosomal aspartyl endopeptidase originally considered a "house keeping enzyme" involved in the clearance of unwanted proteins. However, recent studies have revealed CatD's involvement in apoptosis and autophagy, thus signifying an important function in the proper development and maintenance of multi-cellular organs.
In the mammary gland, matrix degradation and the remodeling process are orchestrated by proteolytic enzymes, but the role of CatD at distinct developmental stages has remained mostly unexplored. Based on our previous studies we sought to address the role of this endopeptidase in mammary gland development and remodeling. By employing a mouse model, we report a previously unidentified participation of CatD in different stages of mammary gland development. Our findings reveal that CatD undergoes distinct protein processing at different stages of mammary gland development, and this customized processing results in differential enzymatic activity (constitutive and low pH activatable) best fitting particular stage(s) of development. In addition, at the onset of involution the N-glycan structure of this endopeptidase switches from a mixed high mannose and hybrid structure to an almost exclusively high mannose type, but reverts back to the original N-glycan composition by day 4 of involution. Our findings illuminate (at least in part) the "raison d'être" for CatD's numerous and highly regulated proteolytic processing steps from the pro-form to the mature enzyme. In the mammary gland, specific cleavage product(s) perform specialized function(s) befitting each stage of remodeling.
It is noteworthy that deregulated synthesis, secretion and glycosylation of CatD are hallmarks of cancer progression. Thus, identifying the role of CatD in a dynamic normal tissue undergoing highly regulated cycles of remodeling could provide valuable information illuminating the deregulation of CatD associated with cancer development and metastasis.




COMMENTARY

Open Access Article

Cathepsin D: Regulation in mammary gland remodeling, misregulation in breast cancer

Evette S. Radisky
Pages 467 - 470
http://dx.doi.org/10.4161/cbt.10.5.12855
Abstract | PDF

Commentary to:

New insights into cathepsin D in mammary tissue development and remodeling

Naira V Margaryan, Dawn A. Kirschmann, Alina Lipavsky, Caleb M. Bailey, Mary J. C. Hendrix and Zhila Khalkhali-Ellis




RESEARCH PAPERS

Open Access Article

Conjugated PDT drug: Photosensitizing activity and tissue distribution of PEGylated pheophorbide a

Valentina Rapozzi, Marina Zacchigna, Stefania Biffi, Chiara Garrovo, Francesca Cateni, Marco Stebel, Sonia Zorzet, Gian Maria Bonora, Sara Drioli and Luigi Xodo
Pages 471 - 482
http://dx.doi.org/10.4161/cbt.10.5.12536
Abstract | PDF

The design of new photosensitizers with enhanced phototoxicity and pharmacokinetic properties remains a central challenge for cancer photodynamic therapy (PDT). In this study, Pheophorbide a (Pba) has been pegylated to methoxypolyethylene glycol (mPEG-Pba) to produce a soluble photosensitizer that exhibits a higher tissue distribution than free Pba. In vitro studies have shown that mPEG-Pba promotes a fairly strong photosensitizing effect in cancer cells, as previously observed for the unpegylated molecule. mPEG-Pba targets the mitochondria where, following photoactivation, ROS are produced which cause a cellular injury by lipid peroxidation. The effect of pegylation on the photosensitizer biodistribution has been examined in different selected organs of female mice, at different time points after intraperitoneal administration of the drug (50 µmol/Kg body weight). Other than free Pba, which showed a low tissue accumulation, mPEG-Pba has been detected in significant amounts (8 to 16 μg/ml) in liver, spleen, duodenum and kidney and, 3-5 hours after intraperitoneal injection, in moderate amounts (3 to 8 μg/ml) in brain and lung. In vivo optical imaging performed on living female C57/BL6 mice bearing a subcutaneous melanoma mass, showed that injected mPEG-Pba distributes all over the body, with an higher uptake in the tumor respect to free Pba. Our results indicate that although pegylation somewhat decreases the phototoxicity, it significantly increases the drug solubility and tissue distribution and tumor uptake of mPEG-Pba, making the conjugate an interesting photosensitizer for PDT.

Open Access Article

Terminal differentiation of chronic myelogenous leukemia cells is induced by targeting of the MUC1-C oncoprotein

Li Yin, Rehan Ahmad, Michio Kosugi, Takeshi Kawano, David Avigan, Richard Stone, Surender Kharbanda and Donald W. Kufe
Pages 483 - 491
http://dx.doi.org/10.4161/cbt.10.5.12584
Abstract | PDF

Chronic myelogenous leukemia (CML) is caused by expression of the Bcr-Abl fusion protein in hematopoietic stem cells. The MUC1-C oncoprotein is expressed in CML blasts and stabilizes Bcr-Abl. The present studies demonstrate that treatment of KU812 and K562 CML cells with GO-201, a cell-penetrating peptide inhibitor of MUC1-C oligomerization, downregulates Bcr-Abl expression and inhibits cell growth. In concert with decreases in Bcr-Abl levels, KU812 and K562 cells responded to GO-201 with induction of a differentiated myeloid phenotype as evidenced by increased expression of CD11b, CD11c and CD14. The results also show that the GO-201-treated cells undergo a late apoptotic/necrotic response, consistent with induction of terminal differentiation. Primary CML blasts expressing MUC1 similarly responded to GO-201 with induction of a more differentiated phenotype and late apoptosis/necrosis. In addition, treatment of KU812 xenografts in nude mice was associated with upregulation of CD11 and tumor regression. These findings indicate that CML blasts respond to targeting of the MUC1-C oncoprotein with induction of terminal differentiation.




COMMENTARY

Open Access Article

The MUC1-C oncoprotein as a target in hematologic malignancies

Jeffrey Schlom
Pages 492 - 494
http://dx.doi.org/10.4161/cbt.10.5.13150
Abstract | PDF

Commentary to:

Terminal differentiation of chronic myelogenous leukemia cells is induced by targeting of the MUC1-C oncoprotein

Li Yin, Rehan Ahmad, Michio Kosugi, Takeshi Kawano, David Avigan, Richard Stone, Surender Kharbanda and Donald W. Kufe




RESEARCH PAPER

Open Access Article

Inhibition of FGFR2 and FGFR1 increases cisplatin sensitivity in ovarian cancer

Claire Cole, Sin Lau, Alison Backen, Andrew Clamp, Graham Rushton, Caroline Dive, Cassandra Hodgkinson, Rhona McVey, Henry Kitchener and Gordon C Jayson
Pages 495 - 504
http://dx.doi.org/10.4161/cbt.10.5.12585
Abstract | PDF

Fibroblast Growth Factors (FGFs) have been implicated in malignant transformation, tumour mitogenesis, angiogenesis and chemoresistance. The aim of this study was to determine which FGFs and FGFRs play functional roles in epithelial ovarian cancer. Restriction enzyme analysis of mRNA revealed that transformation was associated with a switch in FGFR2 and FGFR3, from the IIIc to the IIIb isoform. There was widespread expression of FGFs, including FGF7, in all tissues but, FGF3 and FGF19 were expressed by malignant cell lines and cancer tissue but were not present in normal tissue. Using FGFR-specific shRNAi we demonstrated that reductions in FGFR2 inhibited proliferation of ovarian cancer cell lines in vitro (>50%, p < 0.006), and reduced cisplatin IC50 (>60%, p < 0.0001). Cell cycle analysis revealed increased cisplatin sensitivity was associated with increased G2/M arrest and increased apoptosis. FGFR2 shRNAi reduced growth rates of ovarian tumour xenografts by 20% (p<0.006) and when combined with cisplatin caused a 40% reduction in proliferation rates (p<0.007). In contrast, RNAi-induced reductions in FGFR1 increased SKOV3 cell numbers, with associated changes in cell cycle but had no effect on ES2 cells. However, the cisplatin IC50 was reduced (>50%, p < 0.0001) by FGFR1 shRNAi in both cell lines and there was increased apoptosis (46-50%) compared with control cells (35%) (p < 0.004). Together our data suggest that combining FGFR2 inhibitors with platinum-containing cytotoxic agents for the treatment of epithelial ovarian cancer may yield increased anti-tumour activity. However, data on the inhibition of FGFR1 suggest that broad spectrum FGFR inhibitors may have unexpected effects on proliferation.




COMMENTARY

Open Access Article

Blockade of FGF signaling: Therapeutic promise for ovarian cancer

Mircea Ivan and Daniela Matei
Pages 505 - 508
http://dx.doi.org/10.4161/cbt.10.5.13023
Abstract | PDF

Commentary to:

Inhibition of FGFR2 and FGFR1 increases cisplatin sensitivity in ovarian cancer

Claire Cole, Sin Lau, Alison Backen, Andrew Clamp, Graham Rushton, Caroline Dive, Cassandra Hodgkinson, Rhona McVey, Henry Kitchener and Gordon C Jayson




RESEARCH PAPERS

Open Access Article

Genomic profiling of C/EBPβ2 transformed mammary epithelial cells: A role for nuclear interleukin-1β

Alisha Russell, Braden Boone, Aixiang Jiang and Linda Sealy
Pages 509 - 519
http://dx.doi.org/10.4161/cbt.10.5.12725
Abstract | PDF

C/EBPβ is essential for mammary gland growth and development and has been associated with poor prognosis in breast cancer. Overexpression of C/EBPβ2 in MCF10A cells results in a variety of cancer phenotypes including EMT and Erbβ independence. IL1β is dramatically upregulated in MCF10A-C/EBPβ2 cells but there is little, if any, processing to the mature 17 kD form. Although proIL1β has previously been considered to be biologically inactive, we demonstrate proIL1β is not only localized to the nucleus, but is also tightly associated with the chromatin. We show that proIL1β is bound at specific locations in the genome and is positioned in such a way to play a role in the cancer phenotypes observed in MCF10A-C/EBPβ2 cells. Moreover, nuclear IL1β is detected in some human breast tumor samples. This study demonstrates the presence of nuclear proIL1β in transformed mammary epithelial cells providing the first evidence that IL1β may be a dual function cytokine.


Open Access Article

PLCD1 is a functional tumor suppressor inducing G₂/M arrest and frequently methylated in breast cancer

Tingxiu Xiang, Lili Li, Yichao Fan, Yanyan Jiang, Ying Ying , Thomas Choudary Putti, Qian Tao and Guosheng Ren
Pages 520 - 527
http://dx.doi.org/10.4161/cbt.10.5.12726
Abstract | PDF

Chromosome 3p harbors multiple tumor-suppressor genes. PLCD1, located at 3p22, encodes an enzyme that mediates regulatory signaling of energy metabolism, calcium homeostasis and intracellular movement. We investigated the epigenetic alterations of PLCD1 and its tumor suppressor function in breast cancer. Frequent downregulation/silencing of PLCD1 was shown in most breast cancer cell lines by using semi-quantitative PCR. Promoter methylation of PLCD1 was detected in 78% (7/9) of cell lines and 52% (13/25) of primary tumors by Methylation-specific PCR (MSP), but not in any tumor adjacent breast tissues and normal breast tissues, which was further confirmed by bisulfite genomic sequencing (BGS). The silencing of PLCD1 could be reversed by pharmacological demethylation, indicating a methylation-mediated mechanism. Ectopic expression of PLCD1 in silenced breast cancer cells significantly inhibited their colony formation. In addition, PLCD1 inhibited tumor cell migration and induced cell cycle G2/M arrest. Thus, this study for the first time demonstrates the frequent inactivation of PLCD1 by promoter methylation and its tumor inhibitory function in breast cancer. Tumor-specific methylation of PLCD1 might serve as a biomarker for possible early detection and prognosis prediction of breast cancer.