Concha-Benavente F, Srivastava RM, Trivedi S, Lei Y, Chandran U, Seethala RR, Freeman GJ, Ferris RL. Identification of the Cell-Intrinsic and -Extrinsic Pathways Downstream of EGFR and IFNγ That Induce PD-L1 Expression in Head and Neck Cancer.
Cancer Res 2015;
76:1031-43. [PMID:
26676749 DOI:
10.1158/0008-5472.can-15-2001]
[Citation(s) in RCA: 248] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 11/05/2015] [Indexed: 02/07/2023]
Abstract
Many cancer types, including head and neck cancers (HNC), express programmed death ligand 1 (PD-L1). Interaction between PD-L1 and its receptor, programmed death 1 (PD-1), inhibits the function of activated T cells and results in an immunosuppressive microenvironment, but the stimuli that induce PD-L1 expression are not well characterized. Interferon gamma (IFNγ) and the epidermal growth factor receptor (EGFR) utilize Janus kinase 2 (JAK2) as a common signaling node to transmit tumor cell-mediated extrinsic or intrinsic signals, respectively. In this study, we investigated the mechanism by which these factors upregulate PD-L1 expression in HNC cells in the context of JAK/STAT pathway activation, Th1 inflammation, and HPV status. We found that wild-type, overexpressed EGFR significantly correlated with JAK2 and PD-L1 expression in a large cohort of HNC specimens. Furthermore, PD-L1 expression was induced in an EGFR- and JAK2/STAT1-dependent manner, and specific JAK2 inhibition prevented PD-L1 upregulation in tumor cells and enhanced their immunogenicity. Collectively, our findings suggest a novel role for JAK2/STAT1 in EGFR-mediated immune evasion, and therapies targeting this signaling axis may be beneficial to block PD-L1 upregulation found in a large subset of HNC tumors.
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