Clinicopathologic features, tumor immune microenvironment and genomic landscape of Epstein-Barr virus-associated intrahepatic cholangiocarcinoma.

BACKGROUND & AIMS: Little is known about Epstein-Barr virus (EBV)-associated intrahepatic cholangiocarcinoma (EBVaICC) because of its rarity. We aimed to comprehensively investigate the clinicopathology, tumor immune microenvironment (TIME) and genomic landscape of this entity in southern China. METHODS: We evaluated 303 intrahepatic cholangiocarcinomas (ICCs) using in situ hybridization for EBV. We compared clinicopathological parameters between EBVaICC and nonEBVaICC, and we analyzed EBV infection status, tumor-infiltrating lymphocytes (TILs) and genomic features of EBVaICC by immunohistochemistry, double staining, nested PCR, multiplex immunofluorescence staining, fluorescence in situ hybridization and whole-exome sequencing. RESULTS: EBVaICC accounted for 6.6% of ICCs and was associated with EBV latency type I infection and clonal EBV isolates. Patients with EBVaICC were more often female and younger, with solitary tumors, higher HBV infection rates and less frequent cirrhosis; the lymphoepithelioma-like (LEL) subtype was more common in EBVaICC. EBVaICC was associated with a significantly larger TIME component than nonEBVaICC. The LEL subtype of EBVaICC - associated with a significantly increased density and proportion of CD20+ B cells and CD8+ T cells - was associated with significantly higher 2-year survival rates than conventional EBVaICC and nonEBVaICC. Both PD-1 and PD-L1 in TILs, and PD-L1 in tumor cells, were overexpressed in EBVaICC. High PD-L1 expression in tumor cells and high CD8+ TIL densities were significantly more common in EBVaICC than in nonEBVaICC. Seven genes (MUC4, DNAH1, GLI2, LIPE, MYH7, RP11-766F14.2 and WDR36) were mutated in at least 3 patients. EBVaICC had a different mutational pattern to liver fluke-associated cholangiocarcinoma and HBV-associated ICC. CONCLUSIONS: EBVaICC, as a subset of ICC, has unique etiological, clinicopathological and genetic characteristics, with a significantly larger TIME component. Paradoxically, patients with EBVaICC could be candidates for immune checkpoint therapy. LAY SUMMARY: Epstein-Barr virus (EBV) is associated with a subtype of intrahepatic cholangiocarcinoma, with unique clinicopathological and genetic characteristics. The tumor immune microenvironment is also different in this tumor subtype and patients with EBV-associated intrahepatic cholangiocarcinoma may respond well to immune checkpoint inhibitors.

GYS1 induces glycogen accumulation and promotes tumor progression via the NF-κB pathway in Clear Cell Renal Carcinoma.

Metabolism reprogramming is a hallmark of many cancer types. We focused on clear cell renal carcinoma (ccRCC) which is characterized by its clear and glycogen-enriched cytoplasm with unknown reasons. The aim of this study was to identify the clinical significance, biological function, and molecular regulation of glycogen synthase 1 (GYS1) in ccRCC glycogen accumulation and tumor progression. Methods: We determined the clinical relevance of GYS1 and glycogen in ccRCC by immunohistochemistry and periodic acid-schiff staining in fresh tissue and by tissue micro-array. Metabolic profiling with GYS1 depletion was performed by metabolomics analysis. In vitro and xenograft mouse models were used to evaluate the impact of GYS1 on cell proliferation. High-throughput RNA-Seq analyses and co-immunoprecipitation-linked mass spectrometry were used to investigate the downstream targets of GYS1. Flow cytometry and CCK8 assays were performed to determine the effect of GYS1 and sunitinib on cell viability. Results: We observed that GYS1 was significantly overexpressed and glycogen was accumulated in ccRCC tissues. These effects were correlated with unfavorable patient survival. Silencing of GYS1 induced metabolomic perturbation manifested by a carbohydrate metabolism shift. Overexpression of GYS1 promoted tumor growth whereas its silencing suppressed it by activating the canonical NF-κB pathway. The indirect interaction between GYS1 and NF-κB was intermediated by RPS27A, which facilitated the phosphorylation and nuclear import of p65. Moreover, silencing of GYS1 increased the synthetic lethality of ccRCC cells to sunitinib treatment by concomitantly suppressing p65. Conclusions: Our study findings reveal an oncogenic role for GYS1 in cell proliferation and glycogen metabolism in ccRCC. Re-sensitization of ccRCC cells to sunitinib suggests that GYS1 is a useful indicator of unfavorable prognosis as well as a therapeutic target for patients with ccRCC.