Fifth Department of Liver Surgery, Eastern Hepatobiliary Surgery Hospital, The Second Military Medical University, Shanghai 200438, China.
Department of Hepatology, Shanghai Putuo District Central Hospital, Shanghai 200062, China.
Int J Biochem Cell Biol. 2019 May;110:1-8. doi: 10.1016/j.biocel.2019.01.019. Epub 2019 Jan 30.
Immunotherapy is a promising method for the treatment of hepatocellular carcinoma (HCC), in which CD8T cells play a key role. The influence of long noncoding RNA (lncRNA) nuclear-enriched autosomal transcript 1(NEAT1) on the antitumor activity of CD8T cells was clarified in this study.
Peripheral blood mononuclear cells (PBMCs) were isolated from HCC patients, and the expressions of NEAT1 and Tim-3 were determined by qRT-PCR and western blot, respectively. CD8T cell apoptosis and cell percentage were analyzed via flow cytometry. The cytolysis activity of CD8T cells against HCC cells was examined. RNA immunoprecipitation (RIP) and RNA pull-down assay were performed to explore the interaction between NEAT1 and miR-155.
NEAT1 and Tim-3 were up-regulated in the PBMCs of patients with HCC (n = 20) compared with healthy subjects (n = 20). Down-regulation of NEAT1 restrained CD8T cell apoptosis and enhanced the cytolysis activity, while interference of miR-155 showed the opposite effects by up-regulating Tim-3. Binding and interaction between NEAT1 and miR-155 were validated in CD8T cells. Down-regulation of NEAT1 restrained CD8T cell apoptosis and enhanced the cytolysis activity through the miR-155/Tim-3 pathway. Repression of NEAT1 suppressed tumor growth in HCC mice.
Via modulating the miR-155/Tim-3 pathway, repression of NEAT1 restrained CD8T cell apoptosis and enhanced the cytolysis activity against HCC, implying an effective target for improving the outcome of immunotherapy.
免疫疗法是治疗肝细胞癌（HCC）的一种有前途的方法，其中 CD8T 细胞发挥关键作用。本研究旨在阐明长链非编码 RNA（lncRNA）核富集常染色体转录本 1（NEAT1）对 CD8T 细胞抗肿瘤活性的影响。
从 HCC 患者中分离外周血单核细胞（PBMCs），通过 qRT-PCR 和 Western blot 分别测定 NEAT1 和 Tim-3 的表达。通过流式细胞术分析 CD8T 细胞凋亡和细胞百分比。检测 CD8T 细胞对 HCC 细胞的细胞溶解活性。进行 RNA 免疫沉淀（RIP）和 RNA 下拉实验以探索 NEAT1 和 miR-155 之间的相互作用。
与健康受试者（n=20）相比，20 例 HCC 患者的 PBMCs 中 NEAT1 和 Tim-3 上调。下调 NEAT1 可抑制 CD8T 细胞凋亡并增强细胞溶解活性，而干扰 miR-155 通过上调 Tim-3 则表现出相反的效果。在 CD8T 细胞中验证了 NEAT1 与 miR-155 之间的结合和相互作用。下调 NEAT1 通过 miR-155/Tim-3 通路抑制 CD8T 细胞凋亡并增强对 HCC 的细胞溶解活性。抑制 NEAT1 可抑制 HCC 小鼠的肿瘤生长。
通过调节 miR-155/Tim-3 通路，抑制 NEAT1 可抑制 CD8T 细胞凋亡并增强对 HCC 的细胞溶解活性，这表明其是改善免疫疗法效果的有效靶点。
