Tumor endothelial cell‐induced CD8+ T‐cell exhaustion via GPNMB in hepatocellular carcinoma

• Published in: Cancer science Vol. 113; no. 5; pp. 1625 - 1638
• Main Authors: Sakano, Yoshihiro, Noda, Takehiro, Kobayashi, Shogo, Sasaki, Kazuki, Iwagami, Yoshifumi, Yamada, Daisaku, Tomimaru, Yoshito, Akita, Hirofumi, Gotoh, Kunihito, Takahashi, Hidenori, Asaoka, Tadafumi, Tanemura, Masahiro, Wada, Hisashi, Doki, Yuichiro, Eguchi, Hidetoshi
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.05.2022; John Wiley and Sons Inc
• Subjects: Angiogenesis; Antibodies; Apoptosis; Blood vessels; Cancer therapies; CD8 antigen; Cell adhesion & migration; Cytotoxicity; Endothelial cells; Experiments; Gene expression; Glycoproteins; GPNMB; Hepatocellular carcinoma; immune suppression; Immunocompetence; Immunoglobulins; Immunotherapy; Ligands; Liver cancer; Lymphocytes; Lymphocytes T; Melanoma; Metastases; Original; Protein B; Proteins; Software; Therapeutic targets; tumor endothelial cell; Tumor microenvironment; Tumor necrosis factor-TNF; Tumor-infiltrating lymphocytes; Tumorigenesis; Tumors; Vascular endothelial growth factor; tumor endothelial cell; liver cancer; tumor microenvironment; GPNMB; immune suppression
• ISSN: 1347-9032; 1349-7006
• DOI: 10.1111/cas.15331

Tumor endothelial cells (TECs) promote tumor angiogenesis and regulate cytotoxic T cells in the tumor microenvironment. However, the roles of TECs for tumor‐infiltrating T‐cell in hepatocellular carcinoma (HCC) is still unknown. Here, we aimed to investigate how TECs influenced tumor growth and immune responses of HCC focusing on CD8+ T‐cell infiltration and exhaustion. First, TECs were isolated from subcutaneous HCC tumors with murine HCC cell lines (BNL‐T) with magnetic selection of CD31+ cells, and normal endothelial cells (NECs) were isolated from normal liver. Second, immunocompetent mice were injected with BNL‐T alone, BNL‐T + NECs, or BNL‐T + TECs for tumor formation, and the functions and exhaustion of tumor‐infiltrating CD8+ T cells were evaluated. The mice injected with BNL‐T + TEC showed rapid tumorigenesis and a decrease in the number of infiltrating CD8+ T cells. In addition, the percentage of CD8+ T‐cell exhaustion was significantly higher in tumors from the administration of BNL‐T + TEC. Third, the next‐generation sequencing on TECs was performed to identify mRNAs that might be a novel treatment target. The molecule of glycoprotein nonmetastatic melanoma protein B (GPNMB) was identified and the functions of GPNMB was analyzed by silencing of GPNMB expression using small interfering RNAs. The silencing of GPNMB expression in TECs induced the suppression of tumor growth and T‐cell exhaustion. In conclusion, TECs induced tumor‐infiltrating T‐cell exhaustion via GPNMB expression and GPNMB might be a novel therapeutic target in HCC. Tumor endothelial cells induced exhaustion in tumor‐infiltrating T cells by upregulating GPNMB; therefore, GPNMB might be a novel therapeutic target in hepatocellular carcinoma.