| 著者 |
Ajith A, Jayaprasad AG, Chang U, Sreekumar A, Lin M, Bravo-Egana V, Mulloy LL, Horuzsko DD, Carosella ED, Horuzsko A.
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| Abstract |
HLA-G is a non-classical MHC class I molecule with potent immunoregulatory functions that is aberrantly expressed in multiple malignancies, yet its tumor-intrinsic role remains poorly defined. To characterize this potential oncogenic role of HLA-G in clear cell renal cell carcinoma (ccRCC), we utilized integrated transcriptomic, in vitro, and in vivo approaches. Analysis of the Cancer Genome Atlas (TCGA) ccRCC cohort revealed that elevated HLA-G expression was associated with immunosuppressive programs and cell populations. Interrogation of a publicly available ccRCC single-cell RNA sequencing dataset revealed that HLA-G expression within tumor epithelial clusters is associated with hypoxia-driven, metabolic transcriptional programs. Multiplex immunofluorescence of human ccRCC specimens confirmed the presence of tumor cell-intrinsic HLA-G expression in advanced disease. Functional studies using RCC7 cells expressing the full-length canonical HLA-G isoform (RCC7/HLA-G1) demonstrated increased proliferation, migration, clonogenicity, cell-cycle progression, and resistance to apoptosis compared with HLA-G-negative RCC7wt cells. RCC7/HLA-G1 xenografts exhibited accelerated tumor growth accompanied by the activation of proliferative, stemness-related, and metabolic programs. Multi-omics analyses further revealed enhanced mitochondrial activity and redox metabolic adaptation in HLA-G-expressing tumors. Mechanistically, HLA-G expression was associated with increased VEGF-C expression and enhanced VEGFR3 signaling, suggesting the activation of a VEGF-C/VEGFR3-associated pro-survival pathway. In three-dimensional tumor spheroid immune cell co-culture models, HLA-G expression reduced CD8⁺ T-cell-mediated cytotoxicity while promoting regulatory T-cell expansion and macrophage polarization toward an immunosuppressive M2-like phenotype. Collectively, these findings establish HLA-G as a key contributor to tumor progression and immune suppression in ccRCC and support HLA-G as a promising therapeutic target.
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