FAM83A drives PD-L1 expression via ERK signaling and FAM83A/PD-L1 co-expression correlates with poor prognosis in lung adenocarcinoma.

PURPOSE: The purpose of this research was to explore the correlation and prognostic significance of FAM83A and programmed cell death-ligand 1 (PD-L1) protein expression in patients with lung adenocarcinoma (LUAD). METHODS: A total of 130 LUAD specimens and 50 normal lung tissue specimens were analyzed for both FAM83A and PD-L1 expression by immunohistochemistry (IHC) analysis. The effect of FAM83A on PD-L1 and ERK pathway was evaluated by RT-PCR and western blot in vitro. RESULTS: Both FAM83A and PD-L1 were upregulated in patients with LUAD and co-expression of them was significantly associated with tumor stage, metastasis and worse survival in LUAD. Multivariate cox regression analysis revealed that co-expression of FAM83A and PD-L1 was an independent prognostic factor impacting survival. Moreover, experiments in vitro showed FAM83A could promote the expression of PD-L1 through the ERK pathway. CONCLUSION: FAM83A and PD-L1 may be potential therapeutic targets for LUAD. Co-expression of FAM83A and PD-L1 in tumor cells was a credible biomarker predictor for worse survival in resected cases. FAM83A may promote the expression of PD-L1 through ERK signaling pathway, thus causing immune escape of tumor.