Department of Urology, Shanghai Tenth People's Hospital, School of Medicine in Tongji University, Shanghai, China.
Department of Pediatrics Surgery, Ningbo Women and Children's Hospital, Ningbo, China.
Cancer Med. 2023 Dec;12(23):21293-21307. doi: 10.1002/cam4.6605. Epub 2023 Nov 20.
Glypican-3 (GPC3) is highly expressed in testicular yolk sac tumor (TYST). GPC3 has been evaluated as a cancer vaccine for some types of tumors, but little is known on the effects of GPC3 peptide-based therapy on TYST. Here, we evaluated the antitumor effect of GPC3 on TYST and its potential mechanisms.
GPC3 -specific CD8 T cells were induced by vaccine immunization and examined by ELISPOT. The CD8 T cells were purified for testing their cytotoxicity in vitro against TYST cells by CCK-8 and TUNEL assays and in vivo against tumor growth. The influence of GPC3 loading and/or cGAS silencing on the tumor growth, apoptosis and cGAS/STING signaling was tested by immunohistochemistry, immunofluorescence, flow cytometry, and Western blot.
Vaccination with GPC3 induced tumor-specific CD8 T cells that secreted high levels of IFN-γ and granzyme B, and had potent cytotoxicity against TYST in a dose-dependent manner. Adoptive transfer of CD8 T cells and treatment with GPC3 significantly inhibited the growth of TYST tumors, but less effective for cGAS-silenced TYST tumors in vivo. Treatment with GPC3 enhanced the infiltration of CD8 T cells into the tumor environment and their cytotoxicity against TYST tumors in vivo by up-regulating granzyme B and IFN-β expression, but down-regulating GPC3 expression in the tumors. Co-culture of CD8 T cells with TYST in the presence of exogenous GPC3 enhanced peptide-specific CD8 T-cell cytotoxicity in vitro, accompanied by enhancing cGAS, γH2AX, TBK1, and IRF3 phosphorylation in TYST cells, but less effective in cGAS-silenced TYST cells.
These data indicated that GPC3 peptide-specific CD8 T cells had potent antitumor activity against TYST tumor, particularly for combined treatment with the peptide, which was partially dependent on the intratumoral cGAS/STNG signaling. GPC3 peptide vaccine may be valuable for the combination treatment of TYST.
Glypican-3（GPC3）在睾丸卵黄囊瘤（TYST）中高度表达。GPC3 已被评估为某些类型肿瘤的癌症疫苗，但对于 GPC3 肽基治疗对 TYST 的影响知之甚少。在这里，我们评估了 GPC3 对 TYST 的抗肿瘤作用及其潜在机制。
通过疫苗免疫诱导 GPC3 特异性 CD8 T 细胞，并通过 ELISPOT 进行检测。纯化 CD8 T 细胞，通过 CCK-8 和 TUNEL 测定及体内肿瘤生长，检测其对 TYST 细胞的体外细胞毒性。通过免疫组织化学、免疫荧光、流式细胞术和 Western blot 检测 GPC3 加载和/或 cGAS 沉默对肿瘤生长、凋亡和 cGAS/STING 信号的影响。
GPC3 疫苗接种诱导产生了肿瘤特异性 CD8 T 细胞，这些细胞分泌高水平的 IFN-γ 和颗粒酶 B，并以剂量依赖的方式对 TYST 具有强大的细胞毒性。CD8 T 细胞的过继转移和 GPC3 治疗显著抑制了 TYST 肿瘤的生长，但对体内 cGAS 沉默的 TYST 肿瘤效果较差。GPC3 治疗通过上调颗粒酶 B 和 IFN-β 的表达，下调肿瘤中的 GPC3 表达，增强 CD8 T 细胞浸润肿瘤微环境及其对 TYST 肿瘤的细胞毒性，从而增强 CD8 T 细胞对 TYST 肿瘤的浸润及其细胞毒性。在存在外源性 GPC3 的情况下，CD8 T 细胞与 TYST 共培养可增强体外肽特异性 CD8 T 细胞的细胞毒性，伴随着 TYST 细胞中 cGAS、γH2AX、TBK1 和 IRF3 磷酸化的增强，但在 cGAS 沉默的 TYST 细胞中效果较差。
这些数据表明，GPC3 肽特异性 CD8 T 细胞对 TYST 肿瘤具有强大的抗肿瘤活性，特别是与肽联合治疗，这部分依赖于肿瘤内的 cGAS/STNG 信号。GPC3 肽疫苗可能对 TYST 的联合治疗有价值。
