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Pancreatic Neoplasms: HELP
Articles by Ming Sound Tsao
Based on 27 articles published since 2009
(Why 27 articles?)
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Between 2009 and 2019, M. S. Tsao wrote the following 27 articles about Pancreatic Neoplasms.
 
+ Citations + Abstracts
Pages: 1 · 2
1 Clinical Trial A phase II study of erlotinib in gemcitabine refractory advanced pancreatic cancer. 2014

Renouf, D J / Tang, P A / Hedley, D / Chen, E / Kamel-Reid, S / Tsao, M S / Tran-Thanh, D / Gill, S / Dhani, N / Au, H J / Wang, L / Moore, M J. ·British Columbia Cancer Agency, University of British Columbia, Vancouver, BC, Canada. Electronic address: drenouf@bccancer.bc.ca. · Tom Baker Cancer Centre, Calgary, AB, Canada. · University Health Network-Princess Margaret Cancer Centre, Toronto, ON, Canada. · British Columbia Cancer Agency, University of British Columbia, Vancouver, BC, Canada. · Cross Cancer Institute, Edmonton, AB, Canada. ·Eur J Cancer · Pubmed #24857345.

ABSTRACT: BACKGROUND: Erlotinib induced skin toxicity has been associated with clinical benefit in several tumour types. This phase II study evaluated the efficacy of erlotinib, dose escalated to rash, in patients with advanced pancreatic cancer previously treated with gemcitabine. METHODS: Erlotinib was given at an initial dose of 150 mg/day, and the dose was escalated by 50mg every 2 weeks (to a maximum of 300 mg/day) until >grade 1 rash or other dose limiting toxicities occurred. Erlotinib pharmacokinetics were performed, and baseline tumour tissue was collected for mutational analysis and epidermal growth factor receptor (EGFR) expression. The primary end-point was the disease control rate (objective response and stable disease >8 weeks). RESULTS: Fifty-one patients were accrued, and 49 received treatment. Dose-escalation to 200-300 mg of erlotinib was possible in 9/49 (18%) patients. The most common ⩾ grade 3 adverse events included fatigue (6%), rash (4%) and diarrhoea (4%). Thirty-seven patients were evaluable for response, and the best response was stable disease in 12 patients (32% (95% confidence interval (CI) 17-47%)). Disease control was observed in nine patients (24% (95% CI: 10-38%)). Median survival was 3.8 months, and 6 month overall survival rate was 32% (95% CI 19-47%). Mutational analysis and EGFR expression were performed on 29 patients, with 93% having KRAS mutations, none having EGFR mutations, and 86% expressing EGFR. Neither KRAS mutational status nor EGFR expression was associated with survival. CONCLUSIONS: Erlotinib dose escalated to rash was well tolerated but not associated with significant efficacy in non-selected patients with advanced pancreatic cancer.

2 Clinical Trial Molecular predictors of outcome in a phase 3 study of gemcitabine and erlotinib therapy in patients with advanced pancreatic cancer: National Cancer Institute of Canada Clinical Trials Group Study PA.3. 2010

da Cunha Santos, Gilda / Dhani, Neesha / Tu, Dongsheng / Chin, Kayu / Ludkovski, Olga / Kamel-Reid, Suzanne / Squire, Jeremy / Parulekar, Wendy / Moore, Malcolm J / Tsao, Ming Sound. ·Department of Pathology, University Health Network, Ontario Cancer Institute, Princess Margaret Hospital, Toronto, Ontario, Canada. ·Cancer · Pubmed #20824720.

ABSTRACT: BACKGROUND: National Cancer Institute of Canada Clinical Trials Group PA.3 (NCIC CTG PA.3) was a phase 3 study (n = 569) that demonstrated benefits for overall survival and progression-free survival with the addition of the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) erlotinib to gemcitabine in patients with advanced pancreatic carcinoma (APC). Mutation status of the v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) and EGFR gene copy number (GCN) were evaluated as predictive markers in 26% of patients who had tumor samples available for analysis. METHODS: KRAS mutation status was evaluated by direct sequencing of exon 2, and EGFR GCN was determined by fluorescence in situ hybridization (FISH) analysis. The results were correlated with survival, which was the primary endpoint of the trial. RESULTS: KRAS analysis was successful in 117 patients, and EGFR FISH analysis was successful in 107 patients. KRAS mutations were identified in 92 patients (78.6%), and EGFR amplification or high polysomy (FISH-positive results) was identified in 50 patients (46.7%). The hazard ratio of death between gemcitabine/erlotinib and gemcitabine/placebo was 0.66 (95% confidence interval [CI], 0.28-1.57) for patients with wild-type KRAS and 1.07 (95% CI, 0.68-1.66) for patients with mutant KRAS (P value for interaction = .38), and the hazard ratio was 0.6 (95% CI, 0.34-1.07) for FISH-negative patients and 0.90 (95% CI, 0.49-1.65) for FISH-positive patients (P value for interaction = .32). CONCLUSIONS: In a molecular subset analysis of patients from NCIC CTG PA.3, EGFR GCN and KRAS mutation status were not identified as markers predictive of a survival benefit from the combination of erlotinib with gemcitabine for the first-line treatment of APC.

3 Article Tyrosyl phosphorylation of KRAS stalls GTPase cycle via alteration of switch I and II conformation. 2019

Kano, Yoshihito / Gebregiworgis, Teklab / Marshall, Christopher B / Radulovich, Nikolina / Poon, Betty P K / St-Germain, Jonathan / Cook, Jonathan D / Valencia-Sama, Ivette / Grant, Benjamin M M / Herrera, Silvia Gabriela / Miao, Jinmin / Raught, Brian / Irwin, Meredith S / Lee, Jeffrey E / Yeh, Jen Jen / Zhang, Zhong-Yin / Tsao, Ming-Sound / Ikura, Mitsuhiko / Ohh, Michael. ·Department of Laboratory Medicine and Pathobiology, University of Toronto, 661 University Avenue, Toronto, ON, M5G 1M1, Canada. · Department of Biochemistry, University of Toronto, 661 University Avenue, Toronto, ON, M5G 1M1, Canada. · Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto, ON, M5G 1L7, Canada. · Princess Margaret Cancer Centre, University Health Network and Department of Pathology, University of Toronto, Toronto, ON, M5G 1L7, Canada. · Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, 686 Bay Street, Toronto, ON, 5G OA4, Canada. · Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599, USA. · Department of Medicinal Chemistry and Molecular Pharmacology, Center for Cancer Research and Institute for Drug Discovery, Purdue University, 720 Clinic Drive, West Lafayette, IN, 47907, USA. · Department of Surgery, University of North Carolina, Chapel Hill, NC, 27599, USA. · Department of Pharmacology, University of North Carolina, Chapel Hill, NC, 27599, USA. · Department of Laboratory Medicine and Pathobiology, University of Toronto, 661 University Avenue, Toronto, ON, M5G 1M1, Canada. michael.ohh@utoronto.ca. · Department of Biochemistry, University of Toronto, 661 University Avenue, Toronto, ON, M5G 1M1, Canada. michael.ohh@utoronto.ca. ·Nat Commun · Pubmed #30644389.

ABSTRACT: Deregulation of the RAS GTPase cycle due to mutations in the three RAS genes is commonly associated with cancer development. Protein tyrosine phosphatase SHP2 promotes RAF-to-MAPK signaling pathway and is an essential factor in RAS-driven oncogenesis. Despite the emergence of SHP2 inhibitors for the treatment of cancers harbouring mutant KRAS, the mechanism underlying SHP2 activation of KRAS signaling remains unclear. Here we report tyrosyl-phosphorylation of endogenous RAS and demonstrate that KRAS phosphorylation via Src on Tyr32 and Tyr64 alters the conformation of switch I and II regions, which stalls multiple steps of the GTPase cycle and impairs binding to effectors. In contrast, SHP2 dephosphorylates KRAS, a process that is required to maintain dynamic canonical KRAS GTPase cycle. Notably, Src- and SHP2-mediated regulation of KRAS activity extends to oncogenic KRAS and the inhibition of SHP2 disrupts the phosphorylation cycle, shifting the equilibrium of the GTPase cycle towards the stalled 'dark state'.

4 Article Whole genomes define concordance of matched primary, xenograft, and organoid models of pancreas cancer. 2019

Gendoo, Deena M A / Denroche, Robert E / Zhang, Amy / Radulovich, Nikolina / Jang, Gun Ho / Lemire, Mathieu / Fischer, Sandra / Chadwick, Dianne / Lungu, Ilinca M / Ibrahimov, Emin / Cao, Ping-Jiang / Stein, Lincoln D / Wilson, Julie M / Bartlett, John M S / Tsao, Ming-Sound / Dhani, Neesha / Hedley, David / Gallinger, Steven / Haibe-Kains, Benjamin. ·Centre for Computational Biology, Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, United Kingdom. · School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom. · PanCuRx Translational Research Initiative, Ontario Institute of Cancer Research (OICR), Toronto, Ontario, Canada. · Informatics and Bio-computing Program, Ontario Institute for Cancer Research, Toronto, Ontario, Canada. · Princess Margaret Living Biobank Core, University Health Network, Toronto, Ontario, Canada. · Department of Statistical Science, University of Toronto, Toronto, Ontario, Canada. · Department of Pathology, University Health Network, University of Toronto, Toronto, Ontario, Canada. · UHN Program in BioSpecimen Sciences, Department of Pathology, University Health Network, Toronto, Ontario, Canada. · Transformative Pathology, Ontario Institute for Cancer Research, Toronto, Ontario, Canada. · Division of Medical Oncology, Princess Margaret Cancer Centre, Toronto, Ontario, Canada. · Molecular Genetics Department, University of Toronto, Toronto, Ontario, Canada. · Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada. · Hepatobiliary/Pancreatic Surgical Oncology Program, University Health Network, Toronto, Ontario, Canada. · Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada. · Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada. · Vector Institute, Toronto, Ontario, Canada. ·PLoS Comput Biol · Pubmed #30629588.

ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) has the worst prognosis among solid malignancies and improved therapeutic strategies are needed to improve outcomes. Patient-derived xenografts (PDX) and patient-derived organoids (PDO) serve as promising tools to identify new drugs with therapeutic potential in PDAC. For these preclinical disease models to be effective, they should both recapitulate the molecular heterogeneity of PDAC and validate patient-specific therapeutic sensitivities. To date however, deep characterization of the molecular heterogeneity of PDAC PDX and PDO models and comparison with matched human tumour remains largely unaddressed at the whole genome level. We conducted a comprehensive assessment of the genetic landscape of 16 whole-genome pairs of tumours and matched PDX, from primary PDAC and liver metastasis, including a unique cohort of 5 'trios' of matched primary tumour, PDX, and PDO. We developed a pipeline to score concordance between PDAC models and their paired human tumours for genomic events, including mutations, structural variations, and copy number variations. Tumour-model comparisons of mutations displayed single-gene concordance across major PDAC driver genes, but relatively poor agreement across the greater mutational load. Genome-wide and chromosome-centric analysis of structural variation (SV) events highlights previously unrecognized concordance across chromosomes that demonstrate clustered SV events. We found that polyploidy presented a major challenge when assessing copy number changes; however, ploidy-corrected copy number states suggest good agreement between donor-model pairs. Collectively, our investigations highlight that while PDXs and PDOs may serve as tractable and transplantable systems for probing the molecular properties of PDAC, these models may best serve selective analyses across different levels of genomic complexity.

5 Article Omega-3 Fatty Acids Prevent Early Pancreatic Carcinogenesis via Repression of the AKT Pathway. 2018

Ding, Yongzeng / Mullapudi, Bhargava / Torres, Carolina / Mascariñas, Emman / Mancinelli, Georgina / Diaz, Andrew M / McKinney, Ronald / Barron, Morgan / Schultz, Michelle / Heiferman, Michael / Wojtanek, Mireille / Adrian, Kevin / DeCant, Brian / Rao, Sambasiva / Ouellette, Michel / Tsao, Ming-Sound / Bentrem, David J / Grippo, Paul J. ·Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. ding.zheng@northwestern.edu. · Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. mullapudi.bhargav@gmail.com. · Division of Gastroenterology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA. ctorres@uic.edu. · Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. wemascarinas@gmail.com. · Division of Gastroenterology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA. wemascarinas@gmail.com. · Division of Gastroenterology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA. gms891@gmail.com. · Division of Gastroenterology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA. amdiaz@atsu.edu. · Division of Gastroenterology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA. mckinney@uic.edu. · Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. mrbarron01@gmail.com. · Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. buffalosoldierms@gmail.com. · Division of Gastroenterology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA. buffalosoldierms@gmail.com. · Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. mikeheif@gmail.com. · Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. mireillewojtanek@gmail.com. · Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. KevinAdrian@bridgewatermcg.com. · Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. bdecant0823@gmail.com. · Division of Gastroenterology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA. bdecant0823@gmail.com. · Division of Gastroenterology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA. s-rao@northwestern.edu. · Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. mouellet@unmc.edu. · Toronto General Hospital, 200 Elizabeth St., Toronto, ON M5G 2C4, Canada. ming.tsao@uhn.ca. · Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. dbentrem@northwestern.edu. · Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. pgrippo@uic.edu. · Division of Gastroenterology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA. pgrippo@uic.edu. ·Nutrients · Pubmed #30213082.

ABSTRACT: Pancreatic cancer remains a daunting foe despite a vast number of accumulating molecular analyses regarding the mutation and expression status of a variety of genes. Indeed, most pancreatic cancer cases uniformly present with a mutation in the

6 Article Multiplexed Real-Time NMR GTPase Assay for Simultaneous Monitoring of Multiple Guanine Nucleotide Exchange Factor Activities from Human Cancer Cells and Organoids. 2018

Gebregiworgis, Teklab / Marshall, Christopher B / Nishikawa, Tadateru / Radulovich, Nikolina / Sandí, María-José / Fang, Zhenhao / Rottapel, Robert / Tsao, Ming-Sound / Ikura, Mitsuhiko. ·Princess Margaret Cancer Centre , University Health Network , Toronto , Ontario M5G 1L7 , Canada. · Department of Medical Biophysics , University of Toronto , Toronto , Ontario M5G 1L7 , Canada. · Department of Laboratory Medicine and Pathobiology , University of Toronto , Toronto , Ontario M5S 1A1 , Canada. ·J Am Chem Soc · Pubmed #29543440.

ABSTRACT: Small GTPases (sGTPases) are critical switch-like regulators that mediate several important cellular functions and are often mutated in human cancers. They are activated by guanine nucleotide exchange factors (GEFs), which specifically catalyze the exchange of GTP for GDP. GEFs coordinate signaling networks in normal cells, and are frequently deregulated in cancers. sGTPase signaling pathways are complex and interconnected; however, most GEF assays do not reveal such complexity. In this Communication, we describe the development of a unique real-time NMR-based multiplexed GEF assay that employs distinct isotopic labeling schemes for each sGTPase protein to enable simultaneous observation of six proteins of interest. We monitor nucleotide exchange of KRas, Rheb, RalB, RhoA, Cdc42 and Rac1 in a single system, and assayed the activities of GEFs in lysates of cultured human cells and 3D organoids derived from pancreatic cancer patients. We observed potent activation of RhoA by lysates of HEK293a cells transfected with GEF-H1, along with weak stimulation of Rac1, which we showed is indirect. Our functional analyses of pancreatic cancer-derived organoids revealed higher GEF activity for RhoA than other sGTPases, in line with RNA-seq data indicating high expression of RhoA-specific GEFs.

7 Article TGFβ engages MEK/ERK to differentially regulate benign and malignant pancreas cell function. 2017

Principe, D R / Diaz, A M / Torres, C / Mangan, R J / DeCant, B / McKinney, R / Tsao, M-S / Lowy, A / Munshi, H G / Jung, B / Grippo, P J. ·University of Illinois College of Medicine, Chicago, IL, USA. · Department of Medicine, University of Illinois, Chicago, IL, USA. · Ontario Cancer Institute/Princess Margaret Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada. · Department of Surgery, University of California San Diego, San Diego, CA, USA. · Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA. ·Oncogene · Pubmed #28368414.

ABSTRACT: While TGFβ signals are anti-proliferative in benign and well-differentiated pancreatic cells, TGFβ appears to promote the progression of advanced cancers. To better understand dysregulation of the TGFβ pathway, we first generated mouse models of neoplastic disease with TGFβ receptor deficiencies. These models displayed reduced levels of pERK irrespective of KRAS mutation. Furthermore, exogenous TGFβ led to rapid and sustained TGFBR1-dependent ERK phosphorylation in benign pancreatic duct cells. Similar to results that our group has published in colon cancer cells, inhibition of ERK phosphorylation in duct cells mitigated TGFβ-induced upregulation of growth suppressive pSMAD2 and p21, prevented downregulation of the pro-growth signal CDK2 and ablated TGFβ-induced EMT. These observations suggest that ERK is a key factor in growth suppressive TGFβ signals, yet may also contribute to detrimental TGFβ signaling such as EMT. In neoplastic PanIN cells, pERK was not necessary for either TGFβ-induced pSMAD2 phosphorylation or CDK2 repression, but was required for upregulation of p21 and EMT indicating a partial divergence between TGFβ and MEK/ERK in early carcinogenesis. In cancer cells, pERK had no effect on TGFβ-induced upregulation of pSMAD2 and p21, suggesting the two pathways have completely diverged with respect to the cell cycle. Furthermore, inhibition of pERK both reduced levels of CDK2 and prevented EMT independent of exogenous TGFβ, consistent with most observations identifying pERK as a tumor promoter. Combined, these data suggest that during carcinogenesis pERK initially facilitates and later antagonizes TGFβ-mediated cell cycle arrest, yet remains critical for the pathological, EMT-inducing arm of TGFβ signaling.

8 Article Senescent Carcinoma-Associated Fibroblasts Upregulate IL8 to Enhance Prometastatic Phenotypes. 2017

Wang, Tao / Notta, Faiyaz / Navab, Roya / Joseph, Joella / Ibrahimov, Emin / Xu, Jing / Zhu, Chang-Qi / Borgida, Ayelet / Gallinger, Steven / Tsao, Ming-Sound. ·Princess Margaret Cancer Centre, University Health Network, Toronto, Canada. · Department of Pathology, University Health Network, Toronto, Canada. · Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada. · Ontario Institute for Cancer Research, Toronto, Canada. · Zane Cohen Centre for Digestive Diseases, Mount Sinai Hospital, Toronto, Canada. · Department of General Surgery, University Health Network, Toronto, Canada. · Department of Surgery, University of Toronto, Toronto, Canada. · Princess Margaret Cancer Centre, University Health Network, Toronto, Canada. ming.tsao@uhn.ca. ·Mol Cancer Res · Pubmed #27678171.

ABSTRACT: Carcinoma-associated fibroblasts (CAF) represent a significant component of pancreatic cancer stroma and are biologically implicated in tumor progression. However, evidence of both cancer-promoting and -restraining properties amongst CAFs suggests the possibility of multiple phenotypic subtypes. Here, it is demonstrated that senescent CAFs promote pancreatic cancer invasion and metastasis compared with nonsenescent control CAFs using in vitro Transwell invasion models and in vivo xenograft mouse models. Screening by gene expression microarray and cytokine ELISA assays revealed IL8 to be upregulated in senescent CAFs. Experimental modulation through IL8 overexpression or receptor inhibition implicates the IL8 pathway as a mediator of the proinvasive effects of senescent CAFs. In a cohort of human pancreatic cancer cases, more abundant stromal senescence as indicated by p16 immunohistochemistry correlated with decreased survival in patients with early-stage disease. These data support senescent fibroblasts as a pathologically and clinically relevant feature of pancreatic cancer. The inhibition of senescent stroma-cancer signaling pathways has the potential to restrain pancreatic cancer progression. IMPLICATIONS: Findings show that senescent cancer-associated fibroblasts secret excess IL8 to promote pancreatic cancer invasion and metastasis; thus, senescent CAFs represent a phenotypic subtype, challenging conventional assumptions that CAFs are a homogeneous population. Mol Cancer Res; 15(1); 3-14. ©2016 AACR.

9 Article A renewed model of pancreatic cancer evolution based on genomic rearrangement patterns. 2016

Notta, Faiyaz / Chan-Seng-Yue, Michelle / Lemire, Mathieu / Li, Yilong / Wilson, Gavin W / Connor, Ashton A / Denroche, Robert E / Liang, Sheng-Ben / Brown, Andrew M K / Kim, Jaeseung C / Wang, Tao / Simpson, Jared T / Beck, Timothy / Borgida, Ayelet / Buchner, Nicholas / Chadwick, Dianne / Hafezi-Bakhtiari, Sara / Dick, John E / Heisler, Lawrence / Hollingsworth, Michael A / Ibrahimov, Emin / Jang, Gun Ho / Johns, Jeremy / Jorgensen, Lars G T / Law, Calvin / Ludkovski, Olga / Lungu, Ilinca / Ng, Karen / Pasternack, Danielle / Petersen, Gloria M / Shlush, Liran I / Timms, Lee / Tsao, Ming-Sound / Wilson, Julie M / Yung, Christina K / Zogopoulos, George / Bartlett, John M S / Alexandrov, Ludmil B / Real, Francisco X / Cleary, Sean P / Roehrl, Michael H / McPherson, John D / Stein, Lincoln D / Hudson, Thomas J / Campbell, Peter J / Gallinger, Steven. ·Ontario Institute for Cancer Research, Toronto, Ontario M5G 0A3, Canada. · Cancer Genome Project, Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK. · UHN Program in BioSpecimen Sciences, Department of Pathology, University Health Network, Toronto, Ontario M5G 2C4, Canada. · Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada. · Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada. · Department of Computer Science, University of Toronto, Toronto, Ontario M5S 3G4, Canada. · Eppley Institute for Research in Cancer, Nebraska Medical Center, Omaha, Nebraska 68198, USA. · Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada. · Princess Margaret Cancer Centre, University Health Network (UHN), Toronto, Ontario M5G 2M9, Canada. · Division of Surgical Oncology, Sunnybrook Health Sciences Centre, Odette Cancer Centre, Toronto, Ontario M4N 3M5, Canada. · Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota 55905, USA. · Research Institute of the McGill University Health Centre, Montreal, Québec, Canada, H3H 2L9. · Theoretical Biology and Biophysics (T-6) and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico, USA, 87545. · Epithelial Carcinogenesis Group, Spanish National Cancer Research Centre (CNIO), Madrid 28029, Spain. · Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada. · Department of Surgery, University Health Network, Toronto, Ontario M5G 2C4, Canada. · Department of Haematology, University of Cambridge, Cambridge CB2 0XY, UK. ·Nature · Pubmed #27732578.

ABSTRACT: Pancreatic cancer, a highly aggressive tumour type with uniformly poor prognosis, exemplifies the classically held view of stepwise cancer development. The current model of tumorigenesis, based on analyses of precursor lesions, termed pancreatic intraepithelial neoplasm (PanINs) lesions, makes two predictions: first, that pancreatic cancer develops through a particular sequence of genetic alterations (KRAS, followed by CDKN2A, then TP53 and SMAD4); and second, that the evolutionary trajectory of pancreatic cancer progression is gradual because each alteration is acquired independently. A shortcoming of this model is that clonally expanded precursor lesions do not always belong to the tumour lineage, indicating that the evolutionary trajectory of the tumour lineage and precursor lesions can be divergent. This prevailing model of tumorigenesis has contributed to the clinical notion that pancreatic cancer evolves slowly and presents at a late stage. However, the propensity for this disease to rapidly metastasize and the inability to improve patient outcomes, despite efforts aimed at early detection, suggest that pancreatic cancer progression is not gradual. Here, using newly developed informatics tools, we tracked changes in DNA copy number and their associated rearrangements in tumour-enriched genomes and found that pancreatic cancer tumorigenesis is neither gradual nor follows the accepted mutation order. Two-thirds of tumours harbour complex rearrangement patterns associated with mitotic errors, consistent with punctuated equilibrium as the principal evolutionary trajectory. In a subset of cases, the consequence of such errors is the simultaneous, rather than sequential, knockout of canonical preneoplastic genetic drivers that are likely to set-off invasive cancer growth. These findings challenge the current progression model of pancreatic cancer and provide insights into the mutational processes that give rise to these aggressive tumours.

10 Article Targeting hypoxic microenvironment of pancreatic xenografts with the hypoxia-activated prodrug TH-302. 2016

Lohse, Ines / Rasowski, Joanna / Cao, Pinjiang / Pintilie, Melania / Do, Trevor / Tsao, Ming-Sound / Hill, Richard P / Hedley, David W. ·Ontario Cancer Institute and Campbell Family Cancer Research Institute, Princess Margaret Cancer Center, University Health Network, Toronto, Ontario, Canada. · Department of Radiation Medicine Program, Toronto, Ontario, Canada. · Department of STTARR Innovation Center, Toronto, Ontario, Canada. · Department of Pathology, University Health Network, Toronto, Ontario, Canada. · Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada. · Department of Medical Biophysics, Toronto, Ontario, Canada. · Department of Radiation Oncology, Toronto, Ontario, Canada. · Department of Medicine, University of Toronto, Toronto, Ontario, Canada. · Department of Medical Oncology and Haematology, Princess Margaret Cancer Centre, Toronto, Ontario, Canada. ·Oncotarget · Pubmed #27248663.

ABSTRACT: Previous reports have suggested that the hypoxic microenvironment provides a niche that supports tumor stem cells, and that this might explain clinical observations linking hypoxia to metastasis. To test this, we examined the effects of a hypoxia-activated prodrug, TH-302, on the tumor-initiating cell (TIC) frequency of patient-derived pancreatic xenografts (PDX).The frequencies of TIC, measured by limiting dilution assay, varied widely in 11 PDX models, and were correlated with rapid growth but not with the levels of hypoxia. Treatment with either TH-302 or ionizing radiation (IR), to target hypoxic and well-oxygenated regions, respectively, reduced TIC frequency, and the combination of TH-302 and IR was much more effective in all models tested. The combination was also more effective than TH-302 or IR alone controlling tumor growth, particularly treating the more rapidly-growing/hypoxic models. These findings support the clinical utility of hypoxia targeting in combination with radiotherapy to treat pancreatic cancers, but do not provide strong evidence for a hypoxic stem cell niche.

11 Article Ductal pancreatic cancer modeling and drug screening using human pluripotent stem cell- and patient-derived tumor organoids. 2015

Huang, Ling / Holtzinger, Audrey / Jagan, Ishaan / BeGora, Michael / Lohse, Ines / Ngai, Nicholas / Nostro, Cristina / Wang, Rennian / Muthuswamy, Lakshmi B / Crawford, Howard C / Arrowsmith, Cheryl / Kalloger, Steve E / Renouf, Daniel J / Connor, Ashton A / Cleary, Sean / Schaeffer, David F / Roehrl, Michael / Tsao, Ming-Sound / Gallinger, Steven / Keller, Gordon / Muthuswamy, Senthil K. ·Princess Margaret Cancer Center, University Health Network (UHN), University of Toronto, Toronto, Ontario, Canada. · McEwen Center for Regenerative Medicine, University Health Network, Toronto, Ontario, Canada. · Department of Physiology, Western University, London, Ontario, Canada. · Department of Pharmacology, Western University, London, Ontario, Canada. · Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan. · Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan. · Structural Genomics Consortium, Toronto, Ontario, Canada. · Division of Anatomic Pathology, Vancouver General Hospital, Vancouver, British Columbia, Canada. · Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada. · Pancreas Centre British Columbia, Vancouver, British Columbia, Canada. · Division of Medical Oncology, British Columbia Cancer Agency, Vancouver, British Columbia, Canada. · Division of General Surgery, University of Toronto, Toronto, Ontario, Canada. · Department of Pathology, University Health Network, Toronto, Ontario, Canada. ·Nat Med · Pubmed #26501191.

ABSTRACT: There are few in vitro models of exocrine pancreas development and primary human pancreatic adenocarcinoma (PDAC). We establish three-dimensional culture conditions to induce the differentiation of human pluripotent stem cells into exocrine progenitor organoids that form ductal and acinar structures in culture and in vivo. Expression of mutant KRAS or TP53 in progenitor organoids induces mutation-specific phenotypes in culture and in vivo. Expression of TP53(R175H) induces cytosolic SOX9 localization. In patient tumors bearing TP53 mutations, SOX9 was cytoplasmic and associated with mortality. We also define culture conditions for clonal generation of tumor organoids from freshly resected PDAC. Tumor organoids maintain the differentiation status, histoarchitecture and phenotypic heterogeneity of the primary tumor and retain patient-specific physiological changes, including hypoxia, oxygen consumption, epigenetic marks and differences in sensitivity to inhibition of the histone methyltransferase EZH2. Thus, pancreatic progenitor organoids and tumor organoids can be used to model PDAC and for drug screening to identify precision therapy strategies.

12 Article BRCA1 and BRCA2 mutations sensitize to chemotherapy in patient-derived pancreatic cancer xenografts. 2015

Lohse, I / Borgida, A / Cao, P / Cheung, M / Pintilie, M / Bianco, T / Holter, S / Ibrahimov, E / Kumareswaran, R / Bristow, R G / Tsao, M-S / Gallinger, S / Hedley, D W. ·Ontario Cancer Institute and Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada M5G 2M9. · Mount Sinai Hospital, Joseph and Wolf Lebovic Health Complex, Toronto, Ontario, Canada M5G 2M9. · 1] Mount Sinai Hospital, Joseph and Wolf Lebovic Health Complex, Toronto, Ontario, Canada M5G 2M9 [2] Translational Research Initiative in Pancreas Cancer, Ontario Institute for Cancer Research, Toronto, Ontario, Canada M5G 2M9. · 1] Ontario Cancer Institute and Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada M5G 2M9 [2] Mount Sinai Hospital, Joseph and Wolf Lebovic Health Complex, Toronto, Ontario, Canada M5G 2M9. · 1] Ontario Cancer Institute and Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada M5G 2M9 [2] Department of Pathology, University Health Network, Toronto, Ontario, Canada M5G 2M9 [3] Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada M5G 2M9. · 1] Ontario Cancer Institute and Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada M5G 2M9 [2] Translational Research Initiative in Pancreas Cancer, Ontario Institute for Cancer Research, Toronto, Ontario, Canada M5G 2M9 [3] Department of Medical Oncology and Haematology, Princess Margaret Cancer Centre, Toronto, Ontario, Canada M5G 2M9. ·Br J Cancer · Pubmed #26180923.

ABSTRACT: BACKGROUND: Germline mutations of the BRCA tumour suppressors have been associated with increased risk of pancreatic cancer. Clinical evidence suggests that these patients may be more sensitive to treatment with cisplatin. As the frequency of germline BRCA mutations is low, definitive experimental data to support the clinical observations are still missing. METHODS: We tested gemcitabine and cisplatin sensitivity of four BRCA1 and BRCA2 mutant and three BRCA1 and BRCA2 wild-type (WT) patient-derived pancreatic cancer xenografts. RESULTS: We observed treatment sensitivity to gemcitabine and cisplatin in the BRCA WT and mutant models. The BRCA1 and BRCA2 mutant xenografts were significantly more sensitive to cisplatin although these models also showed sensitivity to gemcitabine. The BRCA1 and BRCA2 WT models showed sensitivity to gemcitabine but not cisplatin. Treatment sensitivity in the xenograft models closely resembled treatment response in the corresponding patients. DISCUSSION: We have characterised a panel of xenografts derived from pancreatic cancer patients carrying germline BRCA mutations, and shown that their genetic features resemble the patient donor. Our results support further clinical testing of treatment regimens combining gemcitabine and platinum drugs in this patient population, as well as preclinical research aiming to identify mechanisms of cisplatin resistance in BRCA mutant pancreatic cancers.

13 Article Coiled-coil domain containing 68 (CCDC68) demonstrates a tumor-suppressive role in pancreatic ductal adenocarcinoma. 2015

Radulovich, N / Leung, L / Ibrahimov, E / Navab, R / Sakashita, S / Zhu, C-Q / Kaufman, E / Lockwood, W W / Thu, K L / Fedyshyn, Y / Moffat, J / Lam, W L / Tsao, M-S. ·1] Princess Margaret Cancer Center, University Health Network, Toronto, ON, Canada [2] Department of Laboratory Medicine and Pathobiology Department, University of Toronto, Toronto, ON, Canada. · 1] Princess Margaret Cancer Center, University Health Network, Toronto, ON, Canada [2] Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada. · Princess Margaret Cancer Center, University Health Network, Toronto, ON, Canada. · British Columbia Cancer Research Centre and Department of Pathology, University of British Columbia, Vancouver, BC, Canada. · Department of Molecular Genetics, Banting & Best Department of Medical Research, University of Toronto, Toronto, ON, Canada. · 1] Princess Margaret Cancer Center, University Health Network, Toronto, ON, Canada [2] Department of Laboratory Medicine and Pathobiology Department, University of Toronto, Toronto, ON, Canada [3] Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada. ·Oncogene · Pubmed #25381825.

ABSTRACT: Using integrative genomics and functional screening, we identified coiled-coil domain containing 68 (CCDC68) as a novel putative tumor suppressor gene (TSG) in pancreatic ductal adenocarcinoma (PDAC). CCDC68 allelic losses were documented in 48% of primary PDAC patient tumors, 50% of PDAC cell lines and 30% of primary patient derived xenografts. We also discovered a single nucleotide polymorphism (SNP) variant (SNP rs1344011) that leads to exon skipping and generation of an unstable protein isoform CCDC68Δ(69-114) in 31% of PDAC patients. Overexpression of full length CCDC68 (CCDC68(wt)) in PANC-1 and Hs.766T PDAC cell lines lacking CDCC68 expression decreased proliferation and tumorigenicity in scid mice. In contrast, the downregulation of endogenous CCDC68 in MIAPaca-2 cells increased tumor growth rate. These effects were not observed with the deletion-containing isoform, CCDC68Δ(69-114).

14 Article The RhoGEF GEF-H1 is required for oncogenic RAS signaling via KSR-1. 2014

Cullis, Jane / Meiri, David / Sandi, Maria Jose / Radulovich, Nikolina / Kent, Oliver A / Medrano, Mauricio / Mokady, Daphna / Normand, Josee / Larose, Jose / Marcotte, Richard / Marshall, Christopher B / Ikura, Mitsuhiko / Ketela, Troy / Moffat, Jason / Neel, Benjamin G / Gingras, Anne-Claude / Tsao, Ming-Sound / Rottapel, Robert. ·Princess Margaret Cancer Center, University Health Network, 101 College Street, Room 8-703, Toronto Medical Discovery Tower, University of Toronto, Toronto, ON M5G 1L7, Canada; Department of Medical Biophysics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada. · Princess Margaret Cancer Center, University Health Network, 101 College Street, Room 8-703, Toronto Medical Discovery Tower, University of Toronto, Toronto, ON M5G 1L7, Canada. · Princess Margaret Cancer Center, University Health Network, 101 College Street, Room 8-703, Toronto Medical Discovery Tower, University of Toronto, Toronto, ON M5G 1L7, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada. · Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Donnelly Centre and Banting and Best Department of Medical Research, 160 College Street, Room 8-804, University of Toronto, Toronto, ON M5S 3E1, Canada. · Princess Margaret Cancer Center, University Health Network, 101 College Street, Room 8-703, Toronto Medical Discovery Tower, University of Toronto, Toronto, ON M5G 1L7, Canada; Department of Medical Biophysics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada. · Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Room 992A, Toronto, ON M5G 1X5, Canada. · Princess Margaret Cancer Center, University Health Network, 101 College Street, Room 8-703, Toronto Medical Discovery Tower, University of Toronto, Toronto, ON M5G 1L7, Canada; Department of Medicine, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Department of Medical Biophysics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Department of Immunology, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Division of Rheumatology, St. Michael's Hospital, 30 Bond Street, Toronto, ON M5B 1W8, Canada. Electronic address: rottapel@uhnresearch.ca. ·Cancer Cell · Pubmed #24525234.

ABSTRACT: Cellular transformation by oncogenic RAS engages the MAPK pathway under strict regulation by the scaffold protein KSR-1. Here, we report that the guanine nucleotide exchange factor GEF-H1 plays a critical role in a positive feedback loop for the RAS/MAPK pathway independent of its RhoGEF activity. GEF-H1 acts as an adaptor protein linking the PP2A B' subunits to KSR-1, thereby mediating the dephosphorylation of KSR-1 S392 and activation of MAPK signaling. GEF-H1 is important for the growth and survival of HRAS(V12)-transformed cells and pancreatic tumor xenografts. GEF-H1 expression is induced by oncogenic RAS and is correlated with pancreatic neoplastic progression. Our results, therefore, identify GEF-H1 as an amplifier of MAPK signaling and provide mechanistic insight into the progression of RAS mutant tumors.

15 Article SOX15 is a candidate tumor suppressor in pancreatic cancer with a potential role in Wnt/β-catenin signaling. 2014

Thu, K L / Radulovich, N / Becker-Santos, D D / Pikor, L A / Pusic, A / Lockwood, W W / Lam, W L / Tsao, M-S. ·BC Cancer Research Centre, Vancouver, BC, Canada. · Ontario Cancer Institute, Princess Margaret Hospital, University Health Network and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada. ·Oncogene · Pubmed #23318427.

ABSTRACT: Pancreatic cancer is among the top five deadliest cancers in developed countries. Better knowledge of the molecular mechanisms contributing to its tumorigenesis is imperative to improve patient prognosis. Identification of novel tumor suppressor genes (TSGs) in pancreatic cancer will reveal new mechanisms of pathway deregulation and will ultimately help improve our understanding of this aggressive disease. According to Knudson's two-hit model, TSGs are classically disrupted by two concerted genetic events. In this study, we combined DNA methylation profiling with copy number and mRNA expression profiling to identify novel TSGs in a set of 20 pancreatic cancer cell lines. These data sets were integrated for each of ∼12 000 genes in each cell line enabling the elucidation of those genes that undergo DNA hypermethylation, copy-number loss and mRNA downregulation simultaneously in multiple cell lines. Using this integrative genomics strategy, we identified SOX15 (sex determining region Y-box 15) as a candidate TSG in pancreatic cancer. Expression of SOX15 in pancreatic cancer cell lines with undetectable expression resulted in reduced viability of cancer cells both in vitro and in vivo demonstrating its tumor suppressive capability. We also found reduced expression, homozygous deletion and aberrant DNA methylation of SOX15 in clinical pancreatic tumor data sets. Furthermore, we deduced a novel role for SOX15 in suppressing the Wnt/β-catenin signaling pathway, which we hypothesize is a pathway through which SOX15 may exert its tumor suppressive effects in pancreatic cancer.

16 Article Loss of canonical Smad4 signaling promotes KRAS driven malignant transformation of human pancreatic duct epithelial cells and metastasis. 2013

Leung, Lisa / Radulovich, Nikolina / Zhu, Chang-Qi / Wang, Dennis / To, Christine / Ibrahimov, Emin / Tsao, Ming-Sound. ·Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada ; Ontario Cancer Institute/Princess Margaret Hospital, and University Health Network, University of Toronto, Toronto, Ontario, Canada. · Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada ; Ontario Cancer Institute/Princess Margaret Hospital, and University Health Network, University of Toronto, Toronto, Ontario, Canada. · Ontario Cancer Institute/Princess Margaret Hospital, and University Health Network, University of Toronto, Toronto, Ontario, Canada. · Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada ; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada ; Ontario Cancer Institute/Princess Margaret Hospital, and University Health Network, University of Toronto, Toronto, Ontario, Canada. ·PLoS One · Pubmed #24386371.

ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) is the fourth most common cause of cancer death in North America. Activating KRAS mutations and Smad4 loss occur in approximately 90% and 55% of PDAC, respectively. While their roles in the early stages of PDAC development have been confirmed in genetically modified mouse models, their roles in the multistep malignant transformation of human pancreatic duct cells have not been directly demonstrated. Here, we report that Smad4 represents a barrier in KRAS-mediated malignant transformation of the near normal immortalized human pancreatic duct epithelial (HPDE) cell line model. Marked Smad4 downregulation by shRNA in KRAS (G12V) expressing HPDE cells failed to cause tumorigenic transformation. However, KRAS-mediated malignant transformation occurred in a new HPDE-TGF-β resistant (TβR) cell line that completely lacks Smad4 protein expression and is resistant to the mito-inhibitory activity of TGF-β. This transformation resulted in tumor formation and development of metastatic phenotype when the cells were implanted orthotopically into the mouse pancreas. Smad4 restoration re-established TGF-β sensitivity, markedly increased tumor latency by promoting apoptosis, and decreased metastatic potential. These results directly establish the critical combination of the KRAS oncogene and complete Smad4 inactivation in the multi-stage malignant transformation and metastatic progression of normal human HPDE cells.

17 Article Alkaline phosphatase ALPPL-2 is a novel pancreatic carcinoma-associated protein. 2013

Dua, Pooja / Kang, Hye Suk / Hong, Seung-Mo / Tsao, Ming-Sound / Kim, Soyoun / Lee, Dong-ki. ·Department of Medical Biotechnology, Dongguk University, Seoul, Korea. ·Cancer Res · Pubmed #23467613.

ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a very low median survival rate. The lack of early sensitive diagnostic markers is one of the main causes of PDAC-associated lethality. Therefore, to identify novel pancreatic cancer biomarkers that can facilitate early diagnosis and also help in the development of effective therapeutics, we developed RNA aptamers targeting pancreatic cancer by Cell-systematic evolution of ligands by exponential enrichment (SELEX) approach. Using a selection strategy that could generate aptamers for 2 pancreatic cancer cell lines in one selection scheme, we identified an aptamer SQ-2 that could recognize pancreatic cancer cells with high specificity. Next, by applying 2 alternative approaches: (i) aptamer-based target pull-down and (ii) genome-wide microarray-based identification of differentially expressed mRNAs in aptamer-positive and -negative cells, we identified alkaline phosphatase placental-like 2 (ALPPL-2), an oncofetal protein, as the target of SQ-2. ALPPL-2 was found to be ectopically expressed in many pancreatic cancer cell lines at both mRNA and protein levels. RNA interference-mediated ALPPL-2 knockdown identified novel tumor-associated functions of this protein in pancreatic cancer cell growth and invasion. In addition, the aptamer-mediated identification of ALPPL-2 on the cell surface and cell secretions of pancreatic cancer cells supports its potential use in the serum- and membrane-based diagnosis of PDAC.

18 Article Regulation of pancreatic cancer growth by superoxide. 2013

Du, Juan / Nelson, Elke S / Simons, Andrean L / Olney, Kristen E / Moser, Justin C / Schrock, Hannah E / Wagner, Brett A / Buettner, Garry R / Smith, Brian J / Teoh, Melissa L T / Tsao, Ming-Sound / Cullen, Joseph J. ·Departments of Radiation Oncology, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA. ·Mol Carcinog · Pubmed #22392697.

ABSTRACT: K-ras mutations have been identified in up to 95% of pancreatic cancers, implying their critical role in the molecular pathogenesis. Expression of K-ras oncogene in an immortalized human pancreatic ductal epithelial cell line, originally derived from normal pancreas (H6c7), induced the formation of carcinoma in mice. We hypothesized that K-ras oncogene correlates with increased non-mitochondrial-generated superoxide (O 2.-), which could be involved in regulating cell growth contributing to tumor progression. In the H6c7 cell line and its derivatives, H6c7er-Kras+ (H6c7 cells expressing K-ras oncogene), and H6c7eR-KrasT (tumorigenic H6c7 cells expressing K-ras oncogene), there was an increase in hydroethidine fluorescence in cell lines that express K-ras. Western blots and activity assays for the antioxidant enzymes that detoxify O 2.- were similar in these cell lines suggesting that the increase in hydroethidine fluorescence was not due to decreased antioxidant capacity. To determine a possible non-mitochondrial source of the increased levels of O 2.-, Western analysis demonstrated the absence of NADPH oxidase-2 (NOX2) in H6c7 cells but present in the H6c7 cell lines expressing K-ras and other pancreatic cancer cell lines. Inhibition of NOX2 decreased hydroethidine fluorescence and clonogenic survival. Furthermore, in the cell lines with the K-ras oncogene, overexpression of superoxide dismutases that detoxify non-mitochondrial sources of O 2.-, and treatment with the small molecule O 2.- scavenger Tempol, also decreased hydroethidine fluorescence, inhibited clonogenic survival and inhibited growth of tumor xenografts. Thus, O 2.- produced by NOX2 in pancreatic cancer cells with K-ras, may regulate pancreatic cancer cell growth.

19 Article Pancreatic cancer genomes reveal aberrations in axon guidance pathway genes. 2012

Biankin, Andrew V / Waddell, Nicola / Kassahn, Karin S / Gingras, Marie-Claude / Muthuswamy, Lakshmi B / Johns, Amber L / Miller, David K / Wilson, Peter J / Patch, Ann-Marie / Wu, Jianmin / Chang, David K / Cowley, Mark J / Gardiner, Brooke B / Song, Sarah / Harliwong, Ivon / Idrisoglu, Senel / Nourse, Craig / Nourbakhsh, Ehsan / Manning, Suzanne / Wani, Shivangi / Gongora, Milena / Pajic, Marina / Scarlett, Christopher J / Gill, Anthony J / Pinho, Andreia V / Rooman, Ilse / Anderson, Matthew / Holmes, Oliver / Leonard, Conrad / Taylor, Darrin / Wood, Scott / Xu, Qinying / Nones, Katia / Fink, J Lynn / Christ, Angelika / Bruxner, Tim / Cloonan, Nicole / Kolle, Gabriel / Newell, Felicity / Pinese, Mark / Mead, R Scott / Humphris, Jeremy L / Kaplan, Warren / Jones, Marc D / Colvin, Emily K / Nagrial, Adnan M / Humphrey, Emily S / Chou, Angela / Chin, Venessa T / Chantrill, Lorraine A / Mawson, Amanda / Samra, Jaswinder S / Kench, James G / Lovell, Jessica A / Daly, Roger J / Merrett, Neil D / Toon, Christopher / Epari, Krishna / Nguyen, Nam Q / Barbour, Andrew / Zeps, Nikolajs / Anonymous5450740 / Kakkar, Nipun / Zhao, Fengmei / Wu, Yuan Qing / Wang, Min / Muzny, Donna M / Fisher, William E / Brunicardi, F Charles / Hodges, Sally E / Reid, Jeffrey G / Drummond, Jennifer / Chang, Kyle / Han, Yi / Lewis, Lora R / Dinh, Huyen / Buhay, Christian J / Beck, Timothy / Timms, Lee / Sam, Michelle / Begley, Kimberly / Brown, Andrew / Pai, Deepa / Panchal, Ami / Buchner, Nicholas / De Borja, Richard / Denroche, Robert E / Yung, Christina K / Serra, Stefano / Onetto, Nicole / Mukhopadhyay, Debabrata / Tsao, Ming-Sound / Shaw, Patricia A / Petersen, Gloria M / Gallinger, Steven / Hruban, Ralph H / Maitra, Anirban / Iacobuzio-Donahue, Christine A / Schulick, Richard D / Wolfgang, Christopher L / Morgan, Richard A / Lawlor, Rita T / Capelli, Paola / Corbo, Vincenzo / Scardoni, Maria / Tortora, Giampaolo / Tempero, Margaret A / Mann, Karen M / Jenkins, Nancy A / Perez-Mancera, Pedro A / Adams, David J / Largaespada, David A / Wessels, Lodewyk F A / Rust, Alistair G / Stein, Lincoln D / Tuveson, David A / Copeland, Neal G / Musgrove, Elizabeth A / Scarpa, Aldo / Eshleman, James R / Hudson, Thomas J / Sutherland, Robert L / Wheeler, David A / Pearson, John V / McPherson, John D / Gibbs, Richard A / Grimmond, Sean M. ·The Kinghorn Cancer Centre, 370 Victoria Street, Darlinghurst, Sydney, New South Wales 2010, Australia. ·Nature · Pubmed #23103869.

ABSTRACT: Pancreatic cancer is a highly lethal malignancy with few effective therapies. We performed exome sequencing and copy number analysis to define genomic aberrations in a prospectively accrued clinical cohort (n = 142) of early (stage I and II) sporadic pancreatic ductal adenocarcinoma. Detailed analysis of 99 informative tumours identified substantial heterogeneity with 2,016 non-silent mutations and 1,628 copy-number variations. We define 16 significantly mutated genes, reaffirming known mutations (KRAS, TP53, CDKN2A, SMAD4, MLL3, TGFBR2, ARID1A and SF3B1), and uncover novel mutated genes including additional genes involved in chromatin modification (EPC1 and ARID2), DNA damage repair (ATM) and other mechanisms (ZIM2, MAP2K4, NALCN, SLC16A4 and MAGEA6). Integrative analysis with in vitro functional data and animal models provided supportive evidence for potential roles for these genetic aberrations in carcinogenesis. Pathway-based analysis of recurrently mutated genes recapitulated clustering in core signalling pathways in pancreatic ductal adenocarcinoma, and identified new mutated genes in each pathway. We also identified frequent and diverse somatic aberrations in genes described traditionally as embryonic regulators of axon guidance, particularly SLIT/ROBO signalling, which was also evident in murine Sleeping Beauty transposon-mediated somatic mutagenesis models of pancreatic cancer, providing further supportive evidence for the potential involvement of axon guidance genes in pancreatic carcinogenesis.

20 Article Lipocalin2 promotes invasion, tumorigenicity and gemcitabine resistance in pancreatic ductal adenocarcinoma. 2012

Leung, Lisa / Radulovich, Nikolina / Zhu, Chang-Qi / Organ, Shawna / Bandarchi, Bizhan / Pintilie, Melania / To, Christine / Panchal, Devang / Tsao, Ming Sound. ·Ontario Cancer Institute/Princess Margaret Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada. ·PLoS One · Pubmed #23056397.

ABSTRACT: Lipocalin 2 (LCN2) is a small secreted protein and its elevated expression has been observed in pancreatic as well as other cancer types. LCN2 has been reported to promote resistance to drug-induced apoptosis, enhance invasion through its physical association with matrix metalloproteinase-9, and promote in vivo tumor growth. LCN2 was found to be commonly expressed in patient PDAC samples and its pattern of immunohistochemical staining intensified with increasing severity in high-grade precursor lesions. Downregulation of LCN2 in two pancreatic ductal adenocarcinoma cell lines (BxPC3 and HPAF-II) with high LCN2 expression significantly reduced attachment, invasion, and tumour growth in vivo, but not proliferation or motility. Downregulation of LCN2 in two pancreatic ductal adenocarcinoma cell lines (BxPC3 and HPAF-II) with high expression significantly reduced attachment, invasion, and tumour growth in vivo. In contrast, LCN2 overexpression in PANC1, with low endogenous expression, significantly increased invasion, attachment, and enhanced tumor growth. Suppression of LCN2 in BxPC3 and HPAF-II cells increased their sensitivity to gemcitabine in vitro, and in vivo when BxPC3 was tested. Furthermore, LCN2 promotes expression of VEGF and HIF1A which contribute to enhanced vascularity. These overall results demonstrate that LCN2 plays an important role in the malignant progression of pancreatic ductal carcinoma and is a potential therapeutic target for this disease.

21 Article Expression of kallikrein-related peptidase 7 predicts poor prognosis in patients with unresectable pancreatic ductal adenocarcinoma. 2012

Iakovlev, Vladimir / Siegel, Eric R / Tsao, Ming-Sound / Haun, Randy S. ·Keenan Research Centre of the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada. ·Cancer Epidemiol Biomarkers Prev · Pubmed #22573795.

ABSTRACT: BACKGROUND: Kallikrein-related peptidase 7 (KLK7) is overexpressed in pancreatic ductal adenocarcinomas (PDAC). The aims of this study were to examine the expression of KLK7 during progression of pancreatic intraepithelial neoplasia (PanIN) to invasive PDAC and to assess its prognostic significance for PDAC. METHODS: Immunohistochemistry was used to assess KLK7 expression using a tissue microarray (TMA) and full sections of pancreatic tissue containing normal tissue, PanIN, and invasive adenocarcinoma, and the association between KLK7 expression and prognosis was examined by a population-based pancreatic cancer TMA. RESULTS: Normal pancreatic epithelium was negative for KLK7 in either TMAs or full sections. Analysis by TMAs showed that 91% of cases showed KLK7 positivity in the adenocarcinoma component, which was significantly higher than PanIN 2/3. In full tissue sections of PDAC, KLK7 expression was detected in less than 1% of cells among PanIN 1A lesions, and increased with grade among PanIN 1B and PanIN2/3 lesions before reaching 69% in the invasive PDAC. In patients with unresected PDAC, KLK7 positivity was significantly associated with shorter overall survival. CONCLUSIONS: Aberrant KLK7 expression starts in intermediate-to-late stages of PanIN progression, and KLK7-positive staining is associated with almost a three-fold increase in mortality rate of patients with unresected PDAC. IMPACT: The association of KLK7 expression and poor outcome of patients with unresectable PDAC suggests that inhibiting either KLK7 expression and/or activity could be a therapeutic strategy. Because the vast majority of patients present with unresectable disease, such an intervention could have a significant impact upon the overall survival of this patient population.

22 Article Overexpression and oncogenic function of aldo-keto reductase family 1B10 (AKR1B10) in pancreatic carcinoma. 2012

Chung, Yeon Tae / Matkowskyj, Kristina A / Li, Haonan / Bai, Han / Zhang, Wanying / Tsao, Ming-Sound / Liao, Jie / Yang, Guang-Yu. ·Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA. ·Mod Pathol · Pubmed #22222635.

ABSTRACT: Aldo-keto reductase family 1B10 (AKR1B10) exhibits more restricted lipid substrate specificity (including farnesal, geranylgeranial, retinal and carbonyls), and metabolizing these lipid substrates has a crucial role in promoting carcinogenesis. Overexpression of AKR1B10 has been identified in smoking-related carcinomas such as lung cancer. As development of pancreatic cancer is firmly linked to smoking, the aim of the present study was to examine the expression and oncogenic role of AKR1B10 in pancreatic adenocarcinoma. AKR1B10 expression was analyzed in 50 paraffin-embedded clinical pancreatic cancer samples using immunohistochemistry. Oncogenic function of AKR1B10 was examined in pancreatic carcinoma cells in vitro using western blotting and siRNA approaches, mainly on cell apoptosis and protein prenylation including KRAS protein and its downstream signals. Immunohistochemistry analysis revealed that AKR1B10 overexpressed in 70% (35/50) of pancreatic adenocarcinomas and majority of pancreatic intraepithelial neoplasia, but not in adjacent morphologically normal pancreatic tissue. Compared with a normal pancreatic ductal epithelial cell (HPDE6E7), all of the six cultured pancreatic adenocarcinoma cell lines had an overexpression of AKR1B10 using immunoblotting, which correlated with increase of enzyme activity. siRNA-mediated silencing of AKR1B10 expression in pancreatic cancer cells resulted in (1) increased cell apoptosis, (2) increased non-farnesyled HDJ2 protein and (3) decreased membrane-bound prenylated KRAS protein and its downstream signaling molecules including phosphorylated ERK and MEK and membrane-bound E-cadherin. Our findings provide first time evidence that AKR1B10 is a unique enzyme involved in pancreatic carcinogenesis possibly via modulation of cell apoptosis and protein prenylation.

23 Article Role of Rac1-dependent NADPH oxidase in the growth of pancreatic cancer. 2011

Du, J / Liu, J / Smith, B J / Tsao, M S / Cullen, J J. ·Department of Radiation Oncology, University of Iowa College of Medicine, Iowa City, IA, USA. ·Cancer Gene Ther · Pubmed #21037555.

ABSTRACT: K-ras mutations occur in as high as 95% of patients with pancreatic cancer. K-ras activates Rac1-dependent NADPH oxidase, a key source of superoxide. Superoxide has an important function in pancreatic cancer cell proliferation, and scavenging or decreasing the levels of superoxide inhibits pancreatic cancer cell growth both in vitro and in vivo. DNA microarray analysis and RT-PCR has demonstrated that Rac1 is also upregulated in pancreatic cancer. The aim of this study was to determine whether inhibiting Rac1 would alter pancreatic tumor cell behavior. Human pancreatic cancer cells with mutant K-ras (MIA PaCa-2), wild-type K-ras (BxPC-3) and the immortal H6c7 cell line (pancreatic ductal epithelium) expressing K-ras oncogene (H6c7eR-KrasT) that is tumorigenic, were infected with a dominant/negative Rac1 construct (AdN17Rac1). In cells with mutant K-ras, AdN17Rac1 decreased rac activity, decreased superoxide levels and inhibited in vitro growth. However, in the BxPC-3 cell line, AdN17Rac1 did not change rac activity, superoxide levels or in vitro cell growth. Additionally, AdN17Rac1 decreased superoxide levels and inhibited in vitro growth in the KrasT tumorigenic cell line, but had no effect in the immortalized H6c7 cell line. In human pancreatic tumor xenografts, intratumoral injections of AdN17Rac1 inhibited tumor growth. These results suggest that activation of Rac1-dependent superoxide generation leads to pancreatic cancer cell proliferation. In pancreatic cancer, inhibition of Rac1 may be a potential therapeutic target.

24 Article Differential roles of cyclin D1 and D3 in pancreatic ductal adenocarcinoma. 2010

Radulovich, Nikolina / Pham, Nhu-An / Strumpf, Dan / Leung, Lisa / Xie, Wing / Jurisica, Igor / Tsao, Ming-Sound. ·Ontario Cancer Institute and Princess Margaret Hospital, University Health Network, Toronto, Ontario M5G 2M9, Canada. ·Mol Cancer · Pubmed #20113529.

ABSTRACT: BACKGROUND: The cyclin D1 (CCND1) and cyclin D3 (CCND3) are frequently co-overexpressed in pancreatic ductal adenocarcinoma (PDAC). Here we examine their differential roles in PDAC. RESULTS: CCND1 and CCND3 expression were selectively suppressed by shRNA in PDAC cell lines with expression levels of equal CCND1 and CCND3 (BxPC3), enhanced CCND1 (HPAC) or enhanced CCND3 (PANC1). Suppression of cell proliferation was greater with CCND3 than CCND1 downregulation. CCND3 suppression led to a reduced level of phosphorylated retinoblastoma protein (Ser795p-Rb/p110) and resulted in decreased levels of cyclin A mRNA and protein. A global gene expression analysis identified deregulated genes in D1- or D3-cyclin siRNA-treated PANC1 cells. The downregulated gene targets in CCND3 suppressed cells were significantly enriched in cell cycle associated processes (p < 0.005). In contrast, focal adhesion/actin cytoskeleton, MAPK and NF B signaling appeared to characterize the target genes and their interacting proteins in CCND1 suppressed PANC1 cells. CONCLUSIONS: Our results suggest that CCND3 is the primary driver of the cell cycle, in cooperation with CCND1 that integrates extracellular mitogenic signaling. We also present evidence that CCND1 plays a role in tumor cell migration. The results provide novel insights for common and differential targets of CCND1 and CCND3 overexpression during pancreatic duct cell carcinogenesis.

25 Article Up-regulation of L1CAM in pancreatic duct cells is transforming growth factor beta1- and slug-dependent: role in malignant transformation of pancreatic cancer. 2009

Geismann, Claudia / Morscheck, Mascha / Koch, Dorothee / Bergmann, Frank / Ungefroren, Hendrik / Arlt, Alexander / Tsao, Ming-Sound / Bachem, Max G / Altevogt, Peter / Sipos, Bence / Fölsch, Ulrich R / Schäfer, Heiner / Müerköster, Susanne Sebens. ·Clinic of Internal Medicine, Laboratory of Molecular Gastroenterology and Hepatology, UKSH-Campus Kiel, Kiel, Germany. ·Cancer Res · Pubmed #19435915.

ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) is thought to originate from ductal structures, exhibiting strong desmoplastic reaction with stromal pancreatic myofibroblasts (PMF), which are supposed to drive PDAC tumorigenesis. Previously, we observed high expression of the adhesion molecule L1CAM (CD171) in PDAC cells accounting for chemoresistance. Thus, this study aimed to investigate whether PMFs are involved in the induction of tumoral L1CAM and whether this contributes to malignant transformation of pancreatic ductal cells and PDAC tumorigenesis. Immunohistochemistry of tissues from chronic pancreatitis specimens revealed considerable L1CAM expression in ductal structures surrounded by dense fibrotic tissue, whereas no L1CAM staining was seen in normal pancreatic tissues. Using the human pancreatic duct cell line H6c7, we show that coculture with PMFs led to a transforming growth factor-beta1 (TGF-beta1)-dependent up-regulation of L1CAM expression. Similarly, L1CAM expression increased in monocultured H6c7 cells after administration of exogenous TGF-beta1. Both TGF-beta1- and PMF-induced L1CAM expression were independent of Smad proteins but required c-Jun NH(2)-terminal kinase activation leading to the induction of the transcription factor Slug. Moreover, Slug interacted with the L1CAM promoter, and its knockdown abrogated the TGF-beta1- and PMF-induced L1CAM expression. As a result of L1CAM expression, H6c7 cells acquired a chemoresistant and migratory phenotype. This mechanism of TGF-beta1-induced L1CAM expression and the resulting phenotype could be verified in the TGF-beta1-responsive PDAC cell lines Colo357 and Panc1. Our data provide new insights into the mechanisms of tumoral L1CAM induction and how PMFs contribute to malignant transformation of pancreatic duct cells early in PDAC tumorigenesis.

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