Language：English   Publishing type：Research paper (scientific journal)  

Immune checkpoint blockade has transformed melanoma therapy but is frequently limited by acquired resistance. Focal adhesion kinase (FAK) and its homolog PYK2 are nonreceptor tyrosine kinases that coordinate cell-matrix adhesion and cytoskeletal signaling. In this study, we define the distinct roles of FAK (as the principal scaffold) and PYK2 (in a supportive capacity) in IFN-γ-mediated immune checkpoint blockade resistance. Label-free phosphoproteomic profiling revealed that IFN-γ stimulation drives extensive phosphorylation across pathways governing cytoskeletal remodeling, transcriptional regulation, mRNA splicing, and ribosomal RNA biogenesis. Selective FAK inhibition markedly suppressed IFN-γ-induced signal transducer and activator of transcription 1 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 Cancer Genome Atlas-Skin Cutaneous Melanoma cohort showed that FAK levels associate with immunosuppressive gene signatures, whereas 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 immune checkpoint blockade resistance in melanoma.

DOI： 10.1016/j.jid.2025.09.376

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

This study investigated the regulation of PD-L1 expression by calcium signaling in oral squamous cell carcinoma (OSCC). We found that IFN-γ stimulation markedly altered the intracellular proteome and activated calcium-associated pathways. Pharmacological inhibition of store-operated calcium entry (SOCE) using the Orai1 inhibitor Synta66 suppressed IFN-γ-induced PD-L1 expression in a dose-dependent manner. Consistently, knockdown of Orai1 or STIM1 attenuated PD-L1 induction under IFN-γ stimulation, while basal expression remained unchanged. Inhibition of CaMK2 and CaMKK2 also reduced PD-L1 expression, indicating involvement of calmodulin-dependent kinase pathways. Functionally, Orai1 or STIM1 knockdown enhanced CD8⁺ T cell-mediated suppression of OSCC cell proliferation. Collectively, these results demonstrate that SOCE-mediated calcium signaling and downstream kinases regulate IFN-γ-induced PD-L1 expression and suggest that targeting SOCE components could represent a novel therapeutic approach to overcoming tumor immune evasion in OSCC. (132 words).

DOI： 10.1016/j.jphyss.2026.100063

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Triple-negative breast cancer (TNBC), which lacks expression of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2), is associated with poor prognosis. Immune checkpoint inhibitors (ICIs) have emerged as a promising therapeutic option for TNBC, but their efficacy remains limited due to resistance. In this study, we investigated whether the non-receptor tyrosine kinase Src (Src tyrosine kinase) regulates interferon-gamma (IFNγ)-induced expression of programmed death-ligand 1 (PD-L1). IFNγ stimulation of TNBC and luminal A breast cancer cell lines induced time-dependent phosphorylation of Src at its activation site (Y419). Pharmacological inhibition of Src significantly suppressed IFNγ-induced PD-L1 mRNA and protein expression, as well as activation of PD-L1-related transcription factors, suggesting transcriptional regulation. In co-culture assays with CD8+ T-cells, TNBC cells were more susceptible to T-cell-mediated cytotoxicity compared with luminal A cells, and Src inhibition further enhanced this cytotoxicity. These findings indicate that Src plays a crucial role in IFNγ-mediated PD-L1 expression and immune evasion in TNBC cell lines. Src inhibition may represent a promising combinatorial strategy to enhance antitumor immunity in TNBC cell lines.

DOI： 10.1016/j.jphs.2025.12.004

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Lymph node metastasis, primarily caused by the migration of oral squamous cell carcinoma (OSCC) cells, stands as a crucial prognostic marker. We have previously demonstrated that EP4, a subtype of the prostaglandin E2 (PGE2) receptor, orchestrates OSCC cell migration via Ca2+ signaling. The exact mechanisms by which EP4 influences cell migration through Ca2+ signaling, however, is unclear. Our study aims to clarify how EP4 controls OSCC cell migration through this pathway. We find that activating EP4 with an agonist (ONO-AE1-473) increased intracellular Ca2+ levels and the migration of human oral cancer cells (HSC-3), but not human gingival fibroblasts (HGnF). Further RNA sequencing linked EP4 to calmodulin-like protein 6 (CALML6), whose role remains undefined in OSCC. Through protein-protein interaction network analysis, a strong connection is identified between CALML6 and calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2), with EP4 activation also boosting mitochondrial function. Overexpressing EP4 in HSC-3 cells increases experimental lung metastasis in mice, whereas inhibiting CaMKK2 with STO-609 markedly lowers these metastases. This positions CaMKK2 as a potential new target for treating OSCC metastasis. Our findings highlight CALML6 as a pivotal regulator in EP4-driven mitochondrial respiration, affecting cell migration and metastasis via the CaMKK2 pathway.

DOI： 10.1038/s42003-024-06231-4

PubMed

researchmap

Language：Japanese   Publisher：(公社)日本皮膚科学会  

researchmap

Language：Japanese   Publisher：(公社)日本皮膚科学会  

researchmap

Language：Japanese   Publisher：(公社)日本皮膚科学会  

researchmap

Language：Japanese   Publisher：(公社)日本皮膚科学会  

researchmap

Language：Japanese   Publisher：(一社)日本臨床免疫学会  

researchmap