1. Academic Validation
  2. FAK-Dependent Reprogramming of IFN-γ Signaling through PYK2 Co-Inhibition Sensitizes Melanoma to Immune Checkpoint Blockade

FAK-Dependent Reprogramming of IFN-γ Signaling through PYK2 Co-Inhibition Sensitizes Melanoma to Immune Checkpoint Blockade

  • J Invest Dermatol. 2025 Oct 14:S0022-202X(25)03407-4. doi: 10.1016/j.jid.2025.09.376.
Yuto Mizuno 1 Masanari Umemura 2 Akane Nagasako 3 Tomoko Akiyama 4 Momoko Nagai 5 Jo Nishino 5 Jordan Ramilowski 6 Yayoi Kimura 4 Mamoru Kato 5 Yukie Yamaguchi 7 Yoshihiro Ishikawa 8
Affiliations

Affiliations

  • 1 Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan; Department of Environmental Immuno-Dermatology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan.
  • 2 Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan. Electronic address: umemurma@yokohama-cu.ac.jp.
  • 3 Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan.
  • 4 Advanced Medical Research Center, Yokohama City University, Yokohama, Kanagawa, Japan.
  • 5 Division of Bioinformatics, Research Institute, National Cancer Center Japan, Tokyo, 104-0045, Japan.
  • 6 Advanced Medical Research Center, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan.
  • 7 Department of Environmental Immuno-Dermatology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan; Advanced Medical Research Center, Yokohama City University, Yokohama, Kanagawa, Japan.
  • 8 Yokohama City University President.
Abstract

Immune checkpoint blockade (ICB) has transformed melanoma therapy but is frequently limited by acquired resistance. Focal adhesion kinase (FAK) and its homolog Pyk2 are non-receptor tyrosine kinases that coordinate cell-matrix adhesion and cytoskeletal signaling. Here, we define the distinct roles of FAK-as the principal scaffold-and PYK2-in a supportive capacity-in IFN-γ-mediated ICB resistance. Label-free phosphoproteomic profiling revealed that IFN-γ stimulation drives extensive phosphorylation across pathways governing cytoskeletal remodeling, transcriptional regulation, mRNA splicing, and rRNA biogenesis. Selective FAK inhibition markedly suppressed IFN-γ-induced STAT1 and PD-L1 upregulation, and the addition of Pyk2 blockade achieved maximal suppression, culminating in enhanced CD8+ T cell-mediated tumor cytotoxicity. In an anti-PD-1-resistant murine melanoma model, high tumoral FAK expression correlated with treatment failure. Analysis of the TCGA-SKCM cohort showed that FAK levels associate with immunosuppressive gene signatures, while in an independent clinical dataset (GSE91061), patients exhibiting post-treatment downregulation of FAK experienced improved outcomes. Single-cell RNA Sequencing distinguished tumor cell-intrinsic FAK expression from Pyk2 enrichment in immune subsets. Together, these data position FAK as the dominant driver of IFN-γ-dependent resistance, with Pyk2 playing a subsidiary role, and suggest that selective FAK targeting-potentially combined with limited Pyk2 inhibition-may overcome ICB resistance in melanoma.

Keywords

FAK; IFN-γ; Immune checkpoint blockade(ICB); PD-L1; melanoma.

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