Browsing by Subject "pancreatic ductal adenocarcinoma (PDAC)"

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    Pancreatic Cancer Signature Center: Providing the Research Tools Necessary to Advance Pancreatic Cancer Patient Care
    (Office of the Vice Chancellor for Research, 2012-04-13) Korc, Murray; Kelley, Mark R.; Howard, Tomas J.
    There were approximately 43,000 new cases of pancreatic ductal adenocarcinoma (PDAC) in the U.S. in 2010, and approximately 37,000 deaths. PDAC thus constitutes the fourth leading cause of cancer deaths, and PDAC patients have a dismal 5-year survival rate of 6%. PDAC is notoriously resistant to chemotherapy and radiation and even with our best treatment options, a complete margin-negative surgical resection, few patients achieving long-term survival. Despite these statistics, surprisingly only a small number of NCI-designated cancer centers have a specialized pancreatic cancer program. The creation of the IUPUI Signature Center for Pancreatic Cancer Research has been the foundation for putting IUPUI, the IU School of Medicine, Purdue University and the IU Simon Cancer Center at the forefront of pancreatic cancer treatment and research across the nation. The Signature Center, comprised of basic, translational and clinical researchers, represents the continuum of the disease from biological / molecular investigation to clinical trials. Funding from the Signature Center Initiative is being utilized to develop genetically engineered mouse models, orthotopic pancreatic cancer models as well as a human pancreatic cancer xenograft model. Establishment and characterization of these in vivo models provides the groundwork to be used by all members in their translational research projects. Additionally, work has begun on a web portal to promote and educate both patients and clinicians about the IUSCC Pancreas Cancer Clinic which became operational in 2010. Taken together the development of these in vivo models as well as web support of the Pancreas Cancer Clinic provides the infrastructure to support pancreas cancer research across the continuum of bench to bedside to practice. The availability of these resources to all members promotes inter-disciplinary collaborations aimed at increasing our understanding of pancreatic cancer so that advancements can be made in diagnosis, prevention and treatment of this malignancy.
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    “Pancreatic Cancer Signature Center: Providing the Research Tools Necessary to Advance Pancreatic Cancer Patient Care”
    (Office of the Vice Chancellor for Research, 2015-04-17) Korc, Murray; Munson, Crystal; Kelley, Mark R.
    There were approximately 45,000 new cases of pancreatic ductal adenocarcinoma (PDAC) in the U.S. in 2013, and approximately 38,500 deaths. PDAC thus constitutes the fourth leading cause of cancer deaths in adults, and PDAC patients have a dismal 5-year survival rate of 6%. Moreover, approximately 75% of patients die within the first year after diagnosis. PDAC is notoriously resistant to chemotherapy and radiation and even with our best treatment options, a complete margin-negative surgical resection, few patients achieve long-term survival. Despite these statistics, surprisingly only a small number of NCI-designated cancer centers have a specialized pancreatic cancer program. The creation of the IUPUI Signature Center for Pancreatic Cancer Research has been the foundation for putting IUPUI, the IU School of Medicine, Purdue University and the IU Simon Cancer Center at the forefront of pancreatic cancer treatment and research across the nation. The Signature Center, comprised of basic, translational and clinical researchers, represents the continuum of the disease from biological/molecular investigation to clinical trials. Funding from the Signature Center Initiative is being utilized to develop genetically engineered mouse models, generate orthotopic pancreatic cancer mouse models, develop cancer associated fibroblast lines to be used as a shared resource as well as provide funding for peer reviewed pilot projects led by young investigators. Establishment and characterization of these cell lines and in vivo models provides the groundwork for these resources to be used by all members in their translational research projects. Support of pilot projects provides preliminary data and identification of projects to be ultimately used in a SPORE application. Additionally, work has begun on a web portal to promote and educate both patients and clinicians about the IUSCC Pancreas Cancer Clinic which became operational in 2010. Taken together, these activities provide the infrastructure to support pancreas cancer research at IU across the continuum of bench to bedside to practice. The availability of these resources to all members promotes inter-disciplinary collaborations aimed at increasing our understanding of pancreatic cancer so that advancements can be made in early diagnosis, prevention and multi-modality targeted treatment of this malignancy.
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    Pathophysiological role of microRNA-29 in pancreatic cancer stroma
    (Office of the Vice Chancellor for Research, 2015-04-17) Kwon, Jason J.; Nabinger, Sarah C.; Alluri, Ravi K.; Vega, Zachary; Sahu, Smiti S.; Abdul-Sater, Zahi; Yu, Zhangsheng; Gore, A. Jesse; Nalepa, Grzegorz; Saxena, Romil; Korc, Murray; Kota, Janaiah
    Background: Dense fibrotic stroma associated with pancreatic ductal adenocarcinoma (PDAC) has been a major obstacle for drug delivery to the tumor bed and may impede attempts to slow down PDAC progression and metastasis. However, current antistromal drugs have not improved tumor response to chemotherapy or patient survival. Thus, a better understanding of the molecular mechanisms associated with tumorstromal interactions is desperately needed to develop novel anti-stromal therapeutic approaches. MicroRNAs (miRNAs) are an abundant class of highly conserved, small non-coding RNAs that function as key regulators of eukaryotic gene expression and cellular homeostasis. miR-29 is known to play a paramount role in the fibrotic process of several organs by providing crucial functions downstream of pro-fibrotic signaling pathways such as TGF-β1 and regulates the expression of extracellular matrix (ECM) proteins, a major component in the PDAC stroma. Upregulation of TGF-β1 is associated with PDAC pathogenesis and is known to activate stromal cells. Furthermore, vascular endothelial growth factor (VEGF) that stimulates tumor angiogenesis is a predicted target of miR-29. We hypothesize that miR-29 may be misregulated in TGF-β1 activated PDAC stromal cells and lead to excessive accumulation of ECM proteins and VEGF. Kwon et al. 2015 Annual AACR Meeting Restored expression of miR-29 could be therapeutically beneficial to modulate tumorstromal interactions. Methods: Northern blot or qPCR techniques were used to assess miR-29 levels in vitro stromal cells, murine PDAC model, and PDAC patient biopsies, and stromal deposition/fibrosis was determined by Sirius red staining. In murine and human PDAC samples, stromal specific miR-29 expression was determined via in situ hybridization by co-staining pancreatic tissues with glial fibrillary acidic protein a marker for stromal cells and miR-29. miR-29 functional studies were conducted by transfection of stroma cells with synthetic miR-29 mimics and locked nucleic acid, a miR-29 inhibitor, and ECM protein/VEGF expression was analyzed by western blot analysis. The effect of miR-29 overexpression in stromal cells on cancer colony growth was evaluated by direct coculture of stromal cells ectopically expressing miR-29 with pancreatic cancer cells, and subsequently, cancer colony number and stromal accumulation was determined by crystal violet and sirius red stains respectively. Results: In both in vitro and in vivo models as well as PDAC patient biopsies, we observed loss of miR-29 is a common phenomenon of activated stromal cells, and is associated with a significant increase in ECM and VEGF accumulation. Restored expression of miR-29 in stromal cells reduced the deposition of matrix proteins, VEGF expression, and cancer colony formation in direct co-culture. Conclusion: These results provide insight into the mechanistic role of miR-29 in PDAC stroma and its potential use as an anti-stromal/angiogenic therapeutic agent.
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    Regulation of HIF1 under Hypoxia by APE1/Ref-1 Impacts CA9 Expression: Dual-Targeting in Patient-Derived 3D Pancreatic Cancer Models
    (Office of the Vice Chancellor for Research, 2016-04-08) Logsdon, Derek P.; Grimard, Michelle; Shahda, Safi; Zyromski, Nicholas; Schipani, Ernestina; Carta, Fabrizio; Supuran, Claudiu T.; Korc, Murray; Ivan, Mircea; Kelley, Mark R.; Fishel, Melissa L.
    Abstract Half of all patients diagnosed with pancreatic ductal adenocarcinoma (PDAC) die within a year despite extensive surgery and/or a highly aggressive chemotherapy regimen. Several mechanisms are proposed to play a role in PDAC therapeutic resistance, including reactive stroma and hypoxia. Hypoxia signaling creates a more aggressive phenotype with increased metastatic potential and impaired therapeutic efficacy. Carbonic anhydrase IX (CA9) functions as part of the cellular hypoxia response to regulate intracellular pH, promoting cell survival. Apurinic/Apyrimidinic Endonuclease-1-Reduction/oxidation Effector Factor 1 (APE1/Ref-1) is a multi-functional protein with two major activities: an endonuclease function in DNA base excision repair and a redox signaling function that reduces oxidized transcription factors, enabling them to bind to their DNA target sequences. APE1/Ref-1 regulates several transcription factors involved in survival mechanisms, tumor growth, and hypoxia signaling. We explored the mechanisms underlying PDAC cell responses to hypoxia and modulation of APE1/Ref-1 redox signaling control of hypoxia inducible factor 1 alpha (HIF1), a critical factor in hypoxiainduced CA9 transcription. We hypothesized that obstructing the HIF-CA9 axis at two points via APE1/Ref-1 inhibition and CA9 inhibition will result in enhanced PDAC cell killing under hypoxic conditions. Methods: We performed qRT-PCR and Western Blots to confirm changes in CA9 expression in PDAC cells following APE1/Ref-1 inhibition and hypoxia exposure. Proliferation assays were used to assess cell killing following inhibition of APE1/Ref-1 and CA9 under hypoxia. Ex vivo 3-Dimensional co-culture models including both tumor and CAFs were used to examine whether we could enhance the efficacy of APE1/Ref-1 and/or CA9 inhibition with a dual-targeting approach to kill tumor spheroids. Results: HIF1-mediated induction of CA9 is significantly diminished in PDAC cells following APE1/Ref-1 redox inhibition. Additionally, dual-targeting of APE1/Ref-1 and CA9 reduces PDAC tumor cell growth under hypoxic conditions and in 3D tumor co-cultures.