GOLM1 upregulates expression of PD-L1 through EGFR/STAT3 pathway in hepatocellular carcinoma

Am J Cancer Res. 2020 Nov 1;10(11):3705-3720. eCollection 2020.

Abstract

GOLM1, a type II transmembrane protein, is associated with tumor progression, metastasis and immunosuppression. However, the relationship between GOLM1 and the immunosuppressive molecule PD-L1 in HCC remains largely unclear. Here, we revealed that GOLM1 acts as a novel positive regulator of PD-L1, whose abnormal expression plays a crucial role in cancer immune evasion and progression. We found that GOLM1 is overexpressed and positively correlated with PD-L1 expression in HCC. Mechanistically, we found that GOLM1 promotes the phosphorylation of STAT3 by enhancing the level of EGFR, which in turn upregulates the transcriptional expression of PD-L1. Taken together, we demonstrated that GOLM1 acts as a positive regulator of PD-L1 expression via the EGFR/STAT3 signaling pathway in human HCC cells. This study provides a new insight into the regulatory mechanism of PD-L1 expression in HCC, which may provide a novel therapeutic target for HCC immunotherapy.

Keywords: EGFR; GOLM1; PD-L1; STAT3; hepatocellular carcinoma.