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Project description:Despite PD-L1 (Programmed death receptor ligand-1) expression on tumor cells and cytotoxic T lymphocytes tumor infiltration in the tumor microenvironment, human pancreatic cancer stands out as one of the human cancers that does not respond to immune checkpoint inhibitor (ICI) immunotherapy. Epigenome dysregulation has emerged as a major mechanism in T cell exhaustion and non-response to ICI immunotherapy, we, therefore, aimed at testing the hypothesis that an epigenetic mechanism compensates PD-L1 function to render pancreatic cancer non-response to ICI immunotherapy. Two orthotopic pancreatic tumor mouse models were used for chromatin immunoprecipitation-Seq and RNA-Seq to identify genome-wide dysregulation of H3K4me3 and gene expression. Human pancreatic tumor and serum were analyzed for osteopontin (OPN) protein level and for correlation with patient prognosis. OPN and PD-L1 cellular location were determined in the tumors using flow cytometry. The function of WDR5-H3K4me3 axis in OPN expression were determined by Western blotting. The function of H3K4me3-OPN axis in pancreatic cancer immune escape and response to ICI immunotherapy was determined in an orthotopic pancreatic tumor mouse model. Mouse pancreatic tumors have a genome-wide increase in H3K4me3 deposition as compared with normal pancreas. OPN and its receptor CD44 were identified being upregulated in pancreatic tumors by their promoter H3K4me3 deposition. OPN protein is increased in both tumor cells and tumor-infiltrating immune cells in human pancreatic carcinoma and is inversely correlated with pancreatic cancer patient survival. OPN is primarily expressed in tumor cells and monocytic myeloid-derived suppressor cells (M-MDSCs), whereas PD-L1 is expressed in tumor cells, M-MDSCs, polymorphonuclear MDSCs and tumor-associated macrophages. WDR5 is essential for H3K4me3-specific histone methyltransferase activity that regulates OPN expression in tumor cells and MDSCs. Inhibition of WDR5 significantly decreased OPN protein level. Inhibition of WDR5 or knocking out of OPN suppressed orthotopic mouse pancreatic tumor growth. Inhibition of WDR5 also significantly increased efficacy of anti-PD-1 immunotherapy in suppression of mouse pancreatic tumor growth in vivo. OPN compensates PD-L1 function to promote pancreatic cancer immune escape. Pharmacological inhibition of the WDR5-H3K4me3 epigenetic axis is effective in suppressing pancreatic tumor immune escape and in improving efficacy of anti-PD-1 immunotherapy in pancreatic cancer.
| S-EPMC8323468 | biostudies-literature
Project description:Two orthotopic pancreatic tumor mouse models were used for ChIP-Seq and RNA-Seq to identify genome-wide dysfunction of H3K4me3 and gene expression. Mouse pancreatic tumors have a genome-wide increase in H3K4me3 deposition as compared to normal pancreas. Osteopontin (OPN) and its receptor CD44 were identified being up-regulated in pancreatic tumors by their promoter H3K4me3 deposition. OPN protein is increased in both tumor cells and tumor-infiltrating immune cells in human pancreatic carcinoma and is inversely correlated with pancreatic cancer patient survival. OPN is primarily expressed in tumor cells and monocytic myeloid-derived suppressor cells (M-MDSCs), whereas PD-L1 is expressed in tumor cells, M-MDSCs, polymorphonuclear MDSCs (PMN-MDSCs) and tumor-associated macrophages. WDR5 is essential for H3K4me3-specific histone methyltransferase activity and OPN expression in tumor cells and MDSCs. Pharmacological inhibition of WDR5 significantly decreased OPN protein level, suppressed pancreatic tumor growth, and significantly increased efficacy of anti-PD-1 immunotherapy in suppression of pancreatic tumor growth in vivo.
2021-07-09 | GSE178676 | GEO
Project description:Total RNA was isolated from normal C57BL/6 mouse pancreas, PANC02-H7, and UN-KC-6141 tumors from tumor-bearing mice. The RNA was used for RNA-Seq. The gene expression profiles between normal mouse pancreas and orthotopic pancreatic tumors were compared, and differentially expressed genes were identified.
2021-07-09 | GSE178675 | GEO
Project description:The WDR5-H3K4me3 epigenetic axis regulates OPN expression to compensate PD-L1 function to promote pancreatic cancer immune escape
| PRJNA739994 | ENA
Project description:The WDR5-H3K4me3 epigenetic axis regulates OPN expression to compensate PD-L1 function to promote pancreatic cancer immune escape [ChIP-seq]
| PRJNA740000 | ENA
Project description:The WDR5-H3K4me3 epigenetic axis regulates OPN expression to compensate PD-L1 function to promote pancreatic cancer immune escape [RNA-seq]
| PRJNA740002 | ENA
Project description:The WDR5/MLL1-H3K4me3 epigenetic axis is often activated in both tumor cells and tumor-infiltrating immune cells to drive various cellular responses in the tumor microenvironment and has been extensively studied in hematopoietic cancer, but its respective functions in tumor cells and immune cells in the context of tumor growth regulation of solid tumor is still incompletely understood. We report here that WDR5 exhibits a higher expression level in human pancreatic tumor tissues compared with adjacent normal pancreas. Moreover, WDR5 expression is negatively correlated with patients' response to chemotherapy or immunotherapy in human colon cancer and melanoma. However, WDR5 expression is positively correlated with the HLA level in human cancer cells, and H3K4me3 enrichment is observed at the promoter region of the HLA-A, HLA-B, and HLA-C genes in pancreatic cancer cells. Using mouse tumor cell lines and in vivo tumor models, we determined that WDR5 deficiency or inhibition significantly represses MHC I expression in vitro and in vivo in pancreatic tumor cells. Mechanistically, we determine that WDR5 deficiency inhibits H3K4me3 deposition at the MHC I (H2K) promoter region to repress MHC I (H2K) transcription. On the other hand, WDR5 depletion leads to the effective downregulation of immune checkpoints and immunosuppressive cytokines, including TGFβ and IL6, in the pancreatic tumor microenvironments. Our data determine that WDR5 not only regulates tumor cell immunogenicity to suppress tumor growth but also activates immune suppressive pathways to promote tumor immune evasion. Selective activation of the WDR5-MHC I pathway and/or selective inhibition of the WDR5-immune checkpoint and WDR5-cytokine pathways should be considered in WDR5-based epigenetic cancer immunotherapy.
| S-EPMC11354242 | biostudies-literature
Project description:BackgroundDPY30 is a common subunit of the human SET1/MLL complex and is an essential protein required for the activity of SET1/MLL methyltransferase. DPY30 regulates the histone H3K4 modification, and dysfunction of DPY30 might contribute to the regulation of cancer immune evasion. However, the functions and regulation of DPY30 in the expression of programmed cell death ligand 1 (PD-L1) is still not completely explored.MethodsVarious online databases were used for data processing and visualization, including UALCAN, Oncomine, cBioPortal, SangerBox, TISIDB, TIMER, and GEPIA databases. The expression of DPY30 and PD-L1 in melanoma tissues were evaluated by IHC. Chromatin Immunoprecipitation (ChIP), RT-PCR and flow cytometry were used to elucidate the underlying molecular mechanism of PD-L1 expression regulation and its function.ResultsThe mRNA level of DPY30 in melanoma was higher than in normal tissues. The expression of DPY30 was positively associated with TMB, neoantigens and PD-L1 expression. Furthermore, DPY30 expression showed significant positive correlations with immune suppressor cells and ICP genes involved in T-cell exhaustion. IHC showed that the positive rates of DPY30 and PD-L1 in melanoma tissues were 62% and 58%, respectively. Correlation analysis revealed that DPY30 over-expression was positively associated with PD-L1 expression. Silencing of DPY30 by specific siRNA significantly inhibited PD-L1 expression. ChIP analysis revealed that H3K4me3 levels were enriched in the proximal PD-L1 promoter region in tumor cells. Inhibition of DPY30 still suppressed the PD-L1 level in IFN-γ treated MMAC-SF cells. Furthermore, the apoptosis of PD1+ T-cells in co-culture with MMAC-SF cells by knockdown of DPY30 were markedly reduced.ConclusionThis study shows the roles of DPY30 in regulating the cancer immune evasion in melanoma. Targeting the DPY30-H3K4me3 axis might be an alternative approach to enhance the efficacy of checkpoint immunotherapy.
| S-EPMC9525212 | biostudies-literature
Project description:PTEN, a widely investigated tumor suppressor, has at least two longer translational variants, PTEN and . However, the regulation and precise roles of endogenous PTEN/ in tumorigenesis remain greatly unknown. Here we show that USP9X and FBXW11 selectively regulate the stability of PTEN/ but not PTEN proteins by deubiqitination and ubiquitination respectively. USP9X promotes and FBXW11 suppresses tumorigenesis mediated by PTEN/. In contrast to the current paradigm for PTEN as a tumor suppressor, PTEN/ promote tumorigenesis of cancer cells in a phosphatase-independent manner. Mechanistically, PTEN/ localized in the nucleus regulate expressions of tumor-promoting genes such as NOTCH3 in the similar way as the H3K4 presenter WDR5. Further, PTEN/ but not PTEN directly interact with WDR5 to promote trimethylation of H3K4 and maintain a tumor-promoting signature. Taken together, our results indicate that PTEN/ are a double-edged sword for carcinogenesis, suggesting that reinterpretation of the importance of PTEN gene in carcinogenesis is warranted.
2019-11-14 | PXD013196 | Pride
Project description:Blockade of programmed cell death 1 (PD-1)/programmed cell death 1 ligand (PD-L1) has evolved into one of the most promising immunotherapy strategies for cancer patients. Tumor cells frequently overexpress PD-L1 to evade T cell-mediated immune surveillance. However, the specific genetic alterations that drive aberrant overexpression of PD-L1 in cancer cells remain poorly understood. The gene encoding the E3 ubiquitin ligase substrate-binding adaptor SPOP is frequently mutated in endometrial cancer (EC). Here, we report that SPOP negatively regulates PD-L1 expression at the transcriptional level. Wild-type SPOP binds to IRF1, a primary transcription factor responsible for the inducible expression of PD-L1, and subsequently triggers its ubiquitin- proteasomal degradation to suppress IRF1-mediated transcriptional upregulation of PD-L1. In contrast, EC-associated SPOP mutants lose their capacity to degrade IRF1 but stabilize IRF1, and upregulate PD-L1 expression. EC-associated SPOP mutations accelerate xenograft tumor growth partially by increasing IRF1 and PD-L1 expression. Together, we identify SPOP as a negative regulator of the IRF1-PD-L1 axis and characterize the critical roles of IRF1 and PD-L1 in SPOP mutation-driven tumor immune evasion in EC.
| S-EPMC9950446 | biostudies-literature