Project description:microRNA profile of human intrahepatic cholangiocarcinoma: intrahepatic cholangiocarcinoma vs. normal intrahepatic bile duct tissue
Project description:Disrupting PD-1/PD-L1 interaction rejuvenates antitumor immunity. Clinical successes by blocking PD-1/PD-L1 binding have grown across wide-ranging cancer histologies, but innate therapy resistance is evident in the majority of treated patients1. Cancer cells can express robust surface levels of PD-L1 to tolerize tumor-specific T cells, but regulation of PD-L1 protein levels in the cancer cell is poorly understood. Quasi-mesenchymal tumor cells up-regulate PD-L1/L2 and induce an immune-suppressive microenvironment, including expansion of M2-like macrophages and regulatory T cells and exclusion of CD8+ T-cell infiltration2. Targeted therapy, including MAPK inhibitor therapy in melanoma, leads to quasi-mesenchymal transitions and resistance3, and both MAPK inhibitor treatment and mesenchymal signatures are associated with innate anti-PD-1 resistance4,5. Here we identify ITCH as an E3 ligase that downregulates tumor cell-surface PD-L1/L2 in PD-L1/L2-high cancer cells, including MAPK inhibitor-resistant melanoma, and suppresses acquired MAPK inhibitor resistance in and only in immune-competent mice. ITCH interacts with and poly-ubiquitinates PD-L1/L2, and ITCH deficiency increases cell-surface PD-L1/L2 expression and reduces T cell activation. Mouse melanoma tumors grow faster with Itch knockdown only in syngeneic hosts but not in immune-deficient mice. MAPK inhibitor therapy induces tumor cell-surface PD-L1 expression in murine melanoma, recapitulating the responses of clinical melanoma3, and this induction is more robust with Itch knockdown. Notably, suppression of ITCH expression first elicits a shift toward an immune-suppressive microenvironment and then accelerates resistance development. These findings collectively identify ITCH as a critical negative regulator of PD-L1 tumor cell-surface expression and provide insights into previously unexplained role of PD-L1 in adaptive resistance to therapy.
Project description:PD-L1 acts as an immune checkpoint that inhibits T cell activation and suppresses colonic inflammation. We aimed at determine the cellular and molecular mechanisms underlying PD-L1 function in colon epithelium and colon cancer. scRNA-seq was perform to determine the gene expression profiles in epithelial cells and immune cells in the single-cell level. Tumors were induced in WT and PD-L1 KO mice. Analysis of WT and PD-L1 KO tumors revealed that loss of PD-L1 alters T cells, myeloid cells, B cells, and tumor-associated fibroblast subpopulations. Our finding determines that PD-L1 regulates multiple cellular populations to regulates host immune response and tumor development.
Project description:Primary outcome(s): Correlation between PD-L1 expression in immune cells and soluble PD-L1 value. Correlation between PD-L1 expression in immune cells or soluble PD-L1 value and PD-L1 expression in tumor tissue. Characterstics of PD-L1 expression in immune cells or soluble PD-L1 value in each gastrointestinal cancer type.
Project description:PD-L1 suppresses host immunity and promotes tumor growth. We investigated how IFN-? regulates PD-L1 in the ovarian cancer microenvironment. In clinical samples, the number of stromal CTLs in peritoneally disseminated tumors was correlated with PD-L1 expression on the tumor cells, and the lymphocyte number was significantly related to the IFN-? signature score. In mouse models, PD-L1 was induced in peritoneal disseminated tumors, where lymphocytes were prominent, but not in subcutaneous tumors. Depleting IFNGR1 resulted in lower PD-L1 expression and longer survival in peritoneal dissemination model. Injection of IFN-? into subcutaneous tumors increased PD-L1 expression and tumor size, and PD-L1 depletion abrogated tumor growth. These data suggest that IFN-? works as a tumor progressor through PD-L1 induction. The source of IFN-? in ovarian cancer microenvironment and its biological effect to the tumor cells is unclear. The immortalized human ovarian surface epithelial cell line, HOSE-E7/hTERT (HOSE) was treated with IFN-? and expression microarray analysis was performed, and probes showing significantly higher values in IFN-?-added group were termed “IFN-? signature genes (295 probes)”. We then applied this signature to our ovarian cancer microarray data, which included 75 ovarian cancer clinical samples, by means of ss-GSEA. IFN-? signature score was strongly correlated to the number of infiltrating CD4-positive or CD8-positive lymphocytes in the tumors. These data suggest that the IFN-? in the ovarian cancer microenvironment is derived from lymphocytes, and an IFN-?-rich microenvironment is strongly correlated to a lymphocyte-rich microenvironment. Genome-wide transcriptional changes in human ovarian cancer tissue were observed in different tumor immunological microenvironment.
Project description:Therapeutic checkpoint antibodies blocking PD1/PD-L1 signaling have radically improved clinical outcomes in cancer. However, the regulation of PD-L1 expression on tumor cells is still poorly understood. Here we show that intra-tumoral copper levels influence PD-L1 expression in cancer cells. Copper supplementation enhanced PD-L1 expression at mRNA and protein levels in cancer cells and RNAseq revealed that copper regulates key signaling pathways mediating PD-L1-driven cancer immune evasion. Conversely, copper chelators inhibited phosphorylation of STAT3 and EGFR and promoted ubiquitin-mediated degradation of PD-L1. Overall, this study reveals an important role for copper in regulating PD-L1 and suggests that anti-cancer immunotherapy might be enhanced by pharmacologically reducing intra-tumor copper levels.