Project description:Senescent cells within tumors and their stroma exert complex pro- and anti-tumorigenic functions, yet the potential for targeting such senescent cells for improved therapy remains largely unknown. Here, we uncover the presence of a senescent subset of cancer-associated fibroblasts (CAFs) within pancreatic ductal adenocarcinomas (PDAC) and in premalignant lesions in mice and humans. Senescent CAFs represented different previously-defined CAF subtypes. Senescent CAFs isolated from mouse and humans expressed elevated levels of immunoregulatory genes. Depletion of senescent CAFs, either genetically or using the Bcl-2 inhibitor ABT-199 (venetoclax), increased the proportion of activated CD8+ T cells in mouse pancreatic carcinomas, whereas induction of CAF senescence had the opposite effect. Combining ABT-199 with an immune checkpoint therapy regimen significantly reduced mouse tumor burden. These results indicate that senescent CAFs in PDAC stroma limit the numbers of activated cytotoxic CD8+ T cells, and suggest that their targeted elimination through senolytic treatment may enhance immunotherapy.
Project description:Senescent cells appear within tumors and their stroma, exerting complex pro- and anti-tumorigenic functions. The effects of senescent tumor stromal cells are mostly unknown, as is the potential for targeting such senescent cells for improved therapy. Here we uncover the presence of a senescent subset of cancer-associated fibroblasts (CAFs) within pancreatic adenocarcinomas and in premalignant pancreatic lesions. Senescent CAFs show reduced proliferation, and are often associated with the inflammatory CAF (iCAF) subtype. We isolated and characterized senescent CAFs from mouse models and directly from human patients, and found that they express elevated levels of immune-regulatory genes. In a panel of mouse PDACs, high levels of senescent CAFs correlated with low T cell infiltration. Removal of senescent CAFs from PDAC stroma, either genetically or through treatment with the senolytic drug ABT-199 (venetoclax), a Bcl2 inhibitor, increased rates of activated cytotoxic CD8+ T cells within tumors. Conversely, activation of CAF senescence within PDACs led to reduced CD8+ T cell numbers. Media from senescent PDAC CAFs inhibited T cell proliferation and activation. We show that implanted PDAC tumors show improved response to immune checkpoint therapy when co-treated with the senolytic drug. These results reveal that the presence of senescent CAFs in PDAC stroma acts to repress cytotoxic T cell activity, and suggest that their targeted elimination through senolytic treatment may enhance immunotherapy.
Project description:Senescent cells appear within tumors and their stroma, exerting complex pro- and anti-tumorigenic functions. The effects of senescent tumor stromal cells are mostly unknown, as is the potential for targeting such senescent cells for improved therapy. Here we uncover the presence of a senescent subset of cancer-associated fibroblasts (CAFs) within pancreatic adenocarcinomas and in premalignant pancreatic lesions. Senescent CAFs show reduced proliferation, and are often associated with the inflammatory CAF (iCAF) subtype. We isolated and characterized senescent CAFs from mouse models and directly from human patients, and found that they express elevated levels of immune-regulatory genes. In a panel of mouse PDACs, high levels of senescent CAFs correlated with low T cell infiltration. Removal of senescent CAFs from PDAC stroma, either genetically or through treatment with the senolytic drug ABT-199 (venetoclax), a Bcl2 inhibitor, increased rates of activated cytotoxic CD8+ T cells within tumors. Conversely, activation of CAF senescence within PDACs led to reduced CD8+ T cell numbers. Media from senescent PDAC CAFs inhibited T cell proliferation and activation. We show that implanted PDAC tumors show improved response to immune checkpoint therapy when co-treated with the senolytic drug. These results reveal that the presence of senescent CAFs in PDAC stroma acts to repress cytotoxic T cell activity, and suggest that their targeted elimination through senolytic treatment may enhance immunotherapy.
Project description:Senescent cells appear within tumors and their stroma, exerting complex pro- and anti-tumorigenic functions. The effects of senescent tumor stromal cells are mostly unknown, as is the potential for targeting such senescent cells for improved therapy. Here we uncover the presence of a senescent subset of cancer-associated fibroblasts (CAFs) within pancreatic adenocarcinomas and in premalignant pancreatic lesions. Senescent CAFs show reduced proliferation, and are often associated with the inflammatory CAF (iCAF) subtype. We isolated and characterized senescent CAFs from mouse models and directly from human patients, and found that they express elevated levels of immune-regulatory genes. In a panel of mouse PDACs, high levels of senescent CAFs correlated with low T cell infiltration. Removal of senescent CAFs from PDAC stroma, either genetically or through treatment with the senolytic drug ABT-199 (venetoclax), a Bcl2 inhibitor, increased rates of activated cytotoxic CD8+ T cells within tumors. Conversely, activation of CAF senescence within PDACs led to reduced CD8+ T cell numbers. Media from senescent PDAC CAFs inhibited T cell proliferation and activation. We show that implanted PDAC tumors show improved response to immune checkpoint therapy when co-treated with the senolytic drug. These results reveal that the presence of senescent CAFs in PDAC stroma acts to repress cytotoxic T cell activity, and suggest that their targeted elimination through senolytic treatment may enhance immunotherapy.
Project description:Comparison of the gene expression profile of senescent versus non-senescent cancer associated fibroblasts. The hypothesis tested is that senescent CAFs secrete higher levels of cytokines that promote cancer progression.
Project description:Cellular senescence is a central barrier to tumorigenesis, acting to block the proliferation of premalignant cells. However, senescent cells residing within tumor lesions can also exert paracrine effects influencing tumor growth and progression. Premalignant pancreatic intraepithelial neoplasia (PanIN) lesions contain senescent cells, yet whether these influence disease progression is unknown. Here we report that senescent cells in PanINs that develop in a Kras-driven mouse model express a pro-inflammatory gene signature, which includes high Cox2 levels. Pharmacologic Cox2 inhibition caused a dramatic reduction in PanIN growth. Senolytic treatment with the Bcl2-family inhibitor ABT-737 reduced the numbers of Cox2-expressing PanIN cells and blocked PanIN formation and progression to carcinoma. These findings indicate that senescent PanIN cells support tumor growth and progression through Cox2 activity, representing crosstalk between interspersed senescent and dividing premalignant cells. Targeted elimination of senescent cells may thus be effective in limiting progression of precancerous lesions.
Project description:With the advent of cancer immunotherapy, intense investigation has been focused on tumor-infiltrating immune cells. With only a fraction of patients responding to these new therapies, a better understanding of all elements of the tumor microenvironment (TME) that may influence therapeutic outcome is needed. Stromal elements of the TME, chiefly fibroblasts, have emerged as potential contributors to tumor progression and most recently resistance to immunotherapy, but their precise composition and clinical relevance remain incompletely understood. Here we use single-cell transcriptomics to chart the fibroblastic landscape during pancreatic ductal adenocarcinoma (PDAC) progression in animal models, identifying two healthy tissue fibroblast subsets that co-evolve along individual trajectories into four subsets of carcinoma-associated fibroblasts (CAFs).
Project description:The tumor microenvironment strongly influences cancer development, progression and metastasis. The role of carcinoma-associated fibroblasts (CAFs) in these processes and their clinical impact has not been studied systematically in non-small cell lung carcinoma (NSCLC). We established primary cultures of CAFs and matched normal fibroblasts (NFs) from 15 resected NSCLC. We demonstrate that CAFs have greater ability than NFs to enhance the tumorigenicity of lung cancer cell lines. Microarray gene expression analysis of the 15 matched CAF and NF cell lines identified 46 differentially expressed genes, encoding for proteins that are significantly enriched for extracellular proteins regulated by the TGF-beta signaling pathway. We have identified a subset of 11 genes that formed a prognostic gene expression signature, which was validated in multiple independent NSCLC microarray datasets. Functional annotation using protein-protein interaction analyses of these and published cancer stroma-associated gene expression changes revealed prominent involvement of the focal adhesion and MAPK signalling pathways. Fourteen (30%) of the 46 genes also were differentially expressed in laser-capture micro-dissected corresponding primary tumor stroma compared to the matched normal lung. Six of these 14 genes could be induced by TGF-beta1 in NF. The results establish the prognostic impact of CAF-associated gene expression changes in NSCLC patients. This SuperSeries is composed of the following subset Series: GSE22862: Prognostic Gene Expression Signature of Carcinoma Associated Fibroblasts in Non-Small Cell Lung Cancer [expression profiling_CAFs] GSE22863: Prognostic Gene Expression Signature of Carcinoma Associated Fibroblasts in Non-Small Cell Lung Cancer [expression profiling_NSCLC stroma] GSE27284: Prognostic Gene Expression Signature of Carcinoma Associated Fibroblasts in Non-Small Cell Lung Cancer [methylation profiling] GSE27289: Prognostic Gene Expression Signature of Carcinoma Associated Fibroblasts in Non-Small Cell Lung Cancer [genome variation profiling]
Project description:This experiment was designed to investigate the intrinsic effect of interleukin-33 (IL-33) on pancreatic cancer associated fibroblasts. IL-33 wildtype (WT) or IL-33 knockout (KO) fibroblasts were grown with or without tumor conditioned media to stimulate cancer-associated fibroblast (CAF) polarization and harvested for bulk RNA sequencing.
Project description:Protease-activated receptor-2 (PAR-2), a G protein-coupled receptor activated by trypsin and coagulant factors, plays broad spectrum of physiological and pathological roles especially in cancer development. In this study, we used PAR-2 activating peptide to mimic the action of trypsin to trigger PAR-2 signaling pathway and effects of PAR-2 activation on gene expression in human pancreatic cancer cell line BxPC-3 investigated by microarray analysis. Through DAVID bioinformatic resources, we observed that activated PAR-2-mediated genes are summarized to two different pathways, renal cell carcinoma and NFkB pathway. In renal cell carcinoma pathway, activated PAR-2 dysregulated hypoxia-inducible factors and its target genes, including glucose transporter 1 (GLUT1), transforming growth factor-b (TGF-b) and vascular endothelial growth factor-A (VEGF-A). In addition, activated PAR-2 induced MAPK signaling and transcriptional factors, such as JUN, MAP2K1 and ETS1. The regulation of these genes by PAR-2 assumed that PAR-2 signaling was associated with cancer progression. On the other hand, activated PAR-2 upregulated interleukin-1b (IL-1b) and toll-like receptor 4 (TLR4) related with NFkB activation, which indicated that PAR-2 signaling may cause cancer-related inflammation. In conclusion, PAR-2 may be a factor to regulate cancer progression and inflammation. Two-condition experiment, control cells vs PAR-2 AP-treated cells.