Project description:Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy that resists current treatments. To test epigenetic therapy against this cancer we used the DNA demethylating drug 5-aza-2’-deoxycytidine (DAC) in a KrasLSL-G12D; p53LSL-R270H/+; Pdx1-cre; Brca1flex2/flex2 (KPC-Brca1) mouse model of aggressive stroma-rich PDAC. In untreated tumors, we found globally decreased 5-methyl-cytosine (5mC) in malignant epithelial cells and in cancer-associated myofibroblasts (CAFs), and increased amounts of 5-hydroxymethyl-cytosine (5HmC) in CAFs, in progression from pancreatic intraepithelial neoplasia (PanIN) to PDAC. DAC further reduced DNA methylation and slowed PDAC progression, markedly extending survival in an early treatment protocol and significantly though transiently inhibiting tumor growth when initiated later, without adverse side effects. Escaping tumors contained areas of sarcomatoid transformation with disappearance of CAFs. Mixing-allografting experiments and proliferation indices showed that DAC efficacy was due to inhibition of both the malignant epithelial cells and the stromal CAFs. Expression profiling and immunohistochemistry highlighted DAC-induction of STAT1 in the tumors, and DAC plus gamma-interferon produced an additive anti-proliferative effect on PDAC cells. DAC induced strong expression of the testis antigen DAZL in CAFs. These data show that DAC is effective against PDAC in vivo and provide a rationale for future studies combining hypomethylating agents with cytokines and immunotherapy. Treatment of a short-term explant culture of malignant epithelial cells from a KPC-Brca1 mouse pancreatic carcinoma, with 0.5 micromolar 5-aza-dC (decitabine; DAC) for 48 hours. The experiment includes 3 replicate plates untreated and 3 replicates treated.
Project description:Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy that resists current treatments. To test epigenetic therapy against this cancer we used the DNA demethylating drug 5-aza-2’-deoxycytidine (DAC) in a KrasLSL-G12D; p53LSL-R270H/+; Pdx1-cre; Brca1flex2/flex2 (KPC-Brca1) mouse model of aggressive stroma-rich PDAC. In untreated tumors, we found globally decreased 5-methyl-cytosine (5mC) in malignant epithelial cells and in cancer-associated myofibroblasts (CAFs), and increased amounts of 5-hydroxymethyl-cytosine (5HmC) in CAFs, in progression from pancreatic intraepithelial neoplasia (PanIN) to PDAC. DAC further reduced DNA methylation and slowed PDAC progression, markedly extending survival in an early treatment protocol and significantly though transiently inhibiting tumor growth when initiated later, without adverse side effects. Escaping tumors contained areas of sarcomatoid transformation with disappearance of CAFs. Mixing-allografting experiments and proliferation indices showed that DAC efficacy was due to inhibition of both the malignant epithelial cells and the stromal CAFs. Expression profiling and immunohistochemistry highlighted DAC-induction of STAT1 in the tumors, and DAC plus gamma-interferon produced an additive anti-proliferative effect on PDAC cells. DAC induced strong expression of the testis antigen DAZL in CAFs. These data show that DAC is effective against PDAC in vivo and provide a rationale for future studies combining hypomethylating agents with cytokines and immunotherapy. Treatment of a short-term explant culture of cancer-associated fibroblasts (CAFs) from a KPC-Brca1 mouse pancreatic carcinoma, with 2 micromolar 5-aza-dC (decitabine; DAC) for 48 hours. The experiment includes 3 replicate plates untreated and 3 replicates treated.
Project description:Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy that resists current treatments. To test epigenetic therapy against this cancer we used the DNA demethylating drug 5-aza-2’-deoxycytidine (DAC) in a KrasLSL-G12D; p53LSL-R270H/+; Pdx1-cre; Brca1flex2/flex2 (KPC-Brca1) mouse model of aggressive stroma-rich PDAC. In untreated tumors, we found globally decreased 5-methyl-cytosine (5mC) in malignant epithelial cells and in cancer-associated myofibroblasts (CAFs), and increased amounts of 5-hydroxymethyl-cytosine (5HmC) in CAFs, in progression from pancreatic intraepithelial neoplasia (PanIN) to PDAC. DAC further reduced DNA methylation and slowed PDAC progression, markedly extending survival in an early treatment protocol and significantly though transiently inhibiting tumor growth when initiated later, without adverse side effects. Escaping tumors contained areas of sarcomatoid transformation with disappearance of CAFs. Mixing-allografting experiments and proliferation indices showed that DAC efficacy was due to inhibition of both the malignant epithelial cells and the stromal CAFs. Expression profiling and immunohistochemistry highlighted DAC-induction of STAT1 in the tumors, and DAC plus gamma-interferon produced an additive anti-proliferative effect on PDAC cells. DAC induced strong expression of the testis antigen DAZL in CAFs. These data show that DAC is effective against PDAC in vivo and provide a rationale for future studies combining hypomethylating agents with cytokines and immunotherapy.
Project description:Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy that resists current treatments. To test epigenetic therapy against this cancer we used the DNA demethylating drug 5-aza-2’-deoxycytidine (DAC) in a KrasLSL-G12D; p53LSL-R270H/+; Pdx1-cre; Brca1flex2/flex2 (KPC-Brca1) mouse model of aggressive stroma-rich PDAC. In untreated tumors, we found globally decreased 5-methyl-cytosine (5mC) in malignant epithelial cells and in cancer-associated myofibroblasts (CAFs), and increased amounts of 5-hydroxymethyl-cytosine (5HmC) in CAFs, in progression from pancreatic intraepithelial neoplasia (PanIN) to PDAC. DAC further reduced DNA methylation and slowed PDAC progression, markedly extending survival in an early treatment protocol and significantly though transiently inhibiting tumor growth when initiated later, without adverse side effects. Escaping tumors contained areas of sarcomatoid transformation with disappearance of CAFs. Mixing-allografting experiments and proliferation indices showed that DAC efficacy was due to inhibition of both the malignant epithelial cells and the stromal CAFs. Expression profiling and immunohistochemistry highlighted DAC-induction of STAT1 in the tumors, and DAC plus gamma-interferon produced an additive anti-proliferative effect on PDAC cells. DAC induced strong expression of the testis antigen DAZL in CAFs. These data show that DAC is effective against PDAC in vivo and provide a rationale for future studies combining hypomethylating agents with cytokines and immunotherapy.
Project description:Gene expression analysis of 5-aza-dC treated pancreatic cancer associated fibroblasts To identify genes silenced by methylation in pancreatic CAFs, we performed gene expression profiling on 5-aza-dC treated pancreatic cancer associated fibroblast cultures using Affymetrix Exon arrays. We analyzed 5 untreated and 5-aza-dC-treated pancreatic cancer associated fibroblast cultures using the Affymetrix Human Exon 1.0 ST platform. Gene expression levels were compared using Partek (version 6.3beta).
Project description:Gene expression analysis of 5-aza-dC treated pancreatic cancer associated fibroblasts To identify genes silenced by methylation in pancreatic CAFs, we performed gene expression profiling on 5-aza-dC treated pancreatic cancer associated fibroblast cultures using Affymetrix Exon arrays.
Project description:Background: Treatment with single-agent decitabine (5aza-dC; DAC), a well-tolerated DNA hypomethylating drug, in a mouse model of pancreatic ductal adenocarcinoma (PDAC), KPC-Brca1, extended the survival of the animals and upregulated immune-related pathways. Here we extend these findings to combination therapy, using DAC followed by the immune checkpoint inhibitor anti-PD-1H in the original more widely utilized KPC (Pdx-Cre Kras/p53) model. Methods: We treated tumor-bearing KPC mice with DAC, and with anti-PD-1H, separately and in combination, and assessed tumor growth, mouse survival, immune cell infiltration of the tumors, and gene expression, compared to historical and mock-treated control mice. Results: Treatment with single-agent DAC led to increased Cd8+ tumor-infiltrating T cells (TILs), increased tumor necrosis, and slower tumor growth. RNA-seq analysis revealed increased expression of a group of myeloid-lineage markers, including Chi3l3 (Ym1), which proved to reflect recruitment or expansion of a unique population of Chi3l3/Arginase-1 double-positive “M2-polarized” tumor-infiltrating myeloid cells. Anti-PD-1H alone had only modest effects on tumor growth and number of Cd8+ TILs. However, PD-1H-expressing TILs were significantly increased by single agent DAC, and DAC treatment followed by anti-PD-1H produced the strongest increase in Cd8+ TILS, inhibition of tumor growth, and prolongation of survival. Conclusions: Treatment with DAC alone, and DAC plus anti-PD-1H, inhibits PDAC tumor growth in the KPC model and produces changes in tumor-infiltrating lymphoid and myeloid cell populations, with an additive therapeutic benefit from combining the two agents. Since the influx of M2-polarized macrophages induced by DAC is predicted to antagonize the anti-tumor effects, future work should investigate eliminating or reprogramming these cells.
Project description:Expression data from pancreatic cancer cell lines and non-neoplastic pancreatic cell line HPDE To identify genes epigenetically silenced and regulated in pancreatic cancer We compared the gene expression profiles of 6 pancreatic cancer cell lines (panc215, A32-1, A38-5, panc2.5, panc2.8, and panc3.014), to the non-neoplastic pancreas cell line, HPDE. We also compared the baseline gene expression of the pancreatic cancer cell lines to expression patterns after treatment with 5-aza-dC alone, TSA alone, and to a combination of 5-aza-dC/TSA.