Characterization and verification of CD81 as a potential target in lung squamous cell carcinoma

CD81 is a cell surface transmembrane protein of the tetraspanin family, which critically regulates signal transduction and immune response. Growing evidence has shown that CD81 plays important roles in tumorigenesis and influences immunotherapy response. Here, combining bio-informatics and functional analysis, we find that CD81 is a risk factor in lung squamous cell carcinoma (LUSC), whereas a protective factor in lung adenocarcinoma. In LUSC with high expression of CD81, the autophagy and JAK-STAT signaling pathway are activated. Meanwhile, the expression level of CD81 is negatively correlated with tumor mutational load (TMB), microsatellite instability (MSI), and neoantigen (NEO). Furthermore, patients with LUSC and high expression of CD81 do not respond to immunotherapy drugs, but can respond to chemotherapy drugs. Importantly, depletion of CD81 suppresses the proliferation of LUSC cell, and enhances the sensitivity to cisplatin. Our findings suggest that CD81 represents a potential target for cisplatin-based chemotherapy in patients with LUSC.