Project description:TGFbeta promotes the bypass of KRAS* dependency in PDAC. To dissect the molecular mechanisms that regulated by TGFbeta in PDAC cells, we conducted RNA-seq analysis of iKPC PDAC cells with or without TGFbeta treatment.
Project description:HDAC5 drives PDAC cells to bypass KRAS* dependency. To dissect the molecular mechanisms that regulated by overexpressed HDAC5 in the bypass of KRAS* dependency, we conducted RNA-seq analysis of HDAC5 escaper PDAC cells and KRAS*-expressing iKPC PDAC cells.
Project description:USP21 promotes PDAC tumor cells to bypass KRAS* dependency. To dissect the molecular mechanism, we conducted RNA-seq analysis comparing iKPC cancer cells overexpressing GFP, wildtype USP21 and enzyme-dead USP21 at day 3 after KRAS* extinction. KRAS*-expressing iKPC cells with GFP overexpression are positive control.
Project description:KRAS* is required for PDAC tumor mantainence. To dissect the molecular mechanisms that regulated by KRAS* in PDAC tumors, we conducted RNA-seq analysis of KRAS*-expressing iKPC PDAC tumors and iKPC tumors after KRAS* extinction for 24 hours.
Project description:USP21 belongs to ubiquitin specific protease (USP) family. To dissect the molecular mechanisms that regulated by USP21 overexpression in PDAC cells, we conducted RNA-seq analysis of iKPC PDAC cells overexpressing wild-type USP21 (WT-USP21) and enzyme dead USP21 (ED-USP21).
Project description:HDAC5 drives PDAC cells to bypass KRAS* dependency. To dissect the molecular mechanisms that regulated by overexpressed HDAC5 in escaper cells, we conducted RNA-seq analysis of HDAC5 escaper PDAC cells knocking down of HDAC5 or scramble shRNA control.
Project description:BACKGROUND & AIMS: Pancreatic ductal adenocarcinoma (PDAC) is characterized by abundant stroma in which microenvironmental (niche) factors promote PDAC progression. In mouse models, reduction of the stroma increased the proportion of poorly differentiated PDAC with a worse prognosis. Here, we aimed to clarify the effects of stroma on PDAC that may define the PDAC phenotype and induce distinct therapeutic responses. METHODS: The molecular features of PDAC based on differentiation grade were clarified by genome and transcriptome analysis using PDAC organoids (PDOs). We identified the dependency on niche factors that might regulate the differentiation grade. A three-dimensional co-culture model with cancer-associated fibroblasts (CAFs) was generated to determine whether CAFs provide niche factors essential for differentiated PDAC. PDOs were subtyped based on niche factor dependency, and the therapeutic responses for each subtype were compared. RESULTS: The expression profiles of PDOs differed depending on the differentiation grade. Consistent with the distinct profiles, well differentiated types showed high niche dependency, while poorly differentiated types showed low niche dependency. The three-dimensional co-culture model revealed that well differentiated PDOs were strongly dependent on CAFs for growth, and moderately differentiated PDOs showed plasticity to change morphology depending on CAFs. Differentiated PDOs upregulated the expression of mevalonate pathway-related genes correlated with the niche dependency and were significantly more sensitive to simvastatin than poorly differentiated PDOs. CONCLUSIONS: Our findings suggest that CAFs maintain the differentiated PDAC phenotype through secreting niche factors and induce distinct drug responses. These results may lead to the development of novel subtype-based therapeutic strategies.
Project description:Activating KRAS mutations (KRAS*) in pancreatic ductal adenocarcinoma (PDAC) drive anabolic metabolism and support tumor maintenance. KRAS* inhibitors show initial anti-tumor activity followed by recurrence due to cancer cell intrinsic and immune mediated paracrine mechanisms. Here, we explored the potential role of cancer associated fibroblasts (CAFs) in enabling KRAS* bypass and identified CAF-derived NRG1 activation of cancer cell ERBB2/ERBB3 receptor tyrosine kinases as a mechanism by which KRAS* independent growth is supported. Genetic extinction or pharmacological inhibition of KRAS* resulted in upregulation of ERBB2 and ERBB3 expression in human and murine models, which prompted cancer cell utilization of CAF-derived NRG1 as a survival factor. Genetic depletion or pharmacological inhibition of ERBB2/ERBB3 or NRG1 abolished KRAS* bypass and synergized with KRASG12D inhibitor in combination treatments in mouse and human PDAC models. Thus, we found that CAFs can contribute to KRAS* inhibitor therapy resistance via paracrine mechanisms, providing an actionable therapeutic strategy to improve the effectiveness of KRAS* inhibitors in PDAC patients.