biostudies-literatureBoyd ALCIHR10108https://www.ebi.ac.uk/biostudies/studies/S-EPMC12562877biostudies-literatureUnknown26(20)Triple-negative breast cancer (TNBC) is an aggressive subtype characterized by limited treatment options and poor prognosis. Although immune checkpoint inhibitors targeting the PD-1/PD-L1 axis have shown clinical promise, many TNBC patients exhibit resistance or limited response, underscoring the need to understand regulatory mechanisms of PD-L1 expression. Here, we performed a kinome-wide inhibitor screen using a HEK293A cell line stably expressing a NanoLuc-tagged PD-L1 construct lacking its endogenous promoter, to identify post-translational regulators of PD-L1 stability. We identified focal adhesion kinase (FAK) as a novel modulator of PD-L1. FAK inhibition significantly decreased PD-L1 levels in HEK293A cells but paradoxically increased PD-L1 expression in TNBC cell lines. MechanisticInternational journal of molecular sciencesKinome-Wide Screening Identifies FAK as a Novel Post-Translational Regulator of PD-L1 Stability and Immune Evasion in Triple-Negative Breast Cancer.PMC12562877186142148629Yang XKelly TKhanal PHao YGe ABoyd ALfalseKinome-Wide Screening Identifies FAK as a Novel Post-Translational Regulator of PD-L1 Stability and Immune Evasion in Triple-Negative Breast Cancer.Triple-negative breast cancer (TNBC) is an aggressive subtype characterized by limited treatment options and poor prognosis. Although immune checkpoint inhibitors targeting the PD-1/PD-L1 axis have shown clinical promise, many TNBC patients exhibit resistance or limited response, underscoring the need to understand regulatory mechanisms of PD-L1 expression. Here, we performed a kinome-wide inhibitor screen using a HEK293A cell line stably expressing a NanoLuc-tagged PD-L1 construct lacking its endogenous promoter, to identify post-translational regulators of PD-L1 stability. We identified focal adhesion kinase (FAK) as a novel modulator of PD-L1. FAK inhibition significantly decreased PD-L1 levels in HEK293A cells but paradoxically increased PD-L1 expression in TNBC cell lines. Mechanistic2025-01-01T00:00:00Z2025 Oct2026-05-14T03:19:19.931Z2026-05-14T03:12:29.154ZS-EPMC125628774115540210.3390/ijms262010108