Kai Yan1, Yong Fu1, Nan Zhu1, Zhuo Wang1, Jin-Ling Hong2, Yao Li3, Wei-Jing Li3, Hai-Bin Zhang4, Jing-Hai Song5. 1. Fifth Department of Liver Surgery, Eastern Hepatobiliary Surgery Hospital, The Second Military Medical University, Shanghai 200438, China. 2. Department of Hepatology, Shanghai Putuo District Central Hospital, Shanghai 200062, China. 3. Department of General Surgery, Beijing Hospital, National Center of Gerontology, Beijing 100730, China. 4. Fifth Department of Liver Surgery, Eastern Hepatobiliary Surgery Hospital, The Second Military Medical University, Shanghai 200438, China. Electronic address: drzhanghaibin@hotmail.com. 5. Department of General Surgery, Beijing Hospital, National Center of Gerontology, Beijing 100730, China. Electronic address: jhaisong2003@163.com.
Abstract
BACKGROUND: Immunotherapy is a promising method for the treatment of hepatocellular carcinoma (HCC), in which CD8+T cells play a key role. The influence of long noncoding RNA (lncRNA) nuclear-enriched autosomal transcript 1(NEAT1) on the antitumor activity of CD8+T cells was clarified in this study. METHODS: 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. CD8+T cell apoptosis and cell percentage were analyzed via flow cytometry. The cytolysis activity of CD8+T 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. RESULTS: 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 CD8+T 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 CD8+T cells. Down-regulation of NEAT1 restrained CD8+T cell apoptosis and enhanced the cytolysis activity through the miR-155/Tim-3 pathway. Repression of NEAT1 suppressed tumor growth in HCC mice. CONCLUSION: Via modulating the miR-155/Tim-3 pathway, repression of NEAT1 restrained CD8+T cell apoptosis and enhanced the cytolysis activity against HCC, implying an effective target for improving the outcome of immunotherapy.
BACKGROUND: Immunotherapy is a promising method for the treatment of hepatocellular carcinoma (HCC), in which CD8+T cells play a key role. The influence of long noncoding RNA (lncRNA) nuclear-enriched autosomal transcript 1(NEAT1) on the antitumor activity of CD8+T cells was clarified in this study. METHODS: 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. CD8+T cell apoptosis and cell percentage were analyzed via flow cytometry. The cytolysis activity of CD8+T 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. RESULTS: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 CD8+T 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 CD8+T cells. Down-regulation of NEAT1 restrained CD8+T cell apoptosis and enhanced the cytolysis activity through the miR-155/Tim-3 pathway. Repression of NEAT1 suppressed tumor growth in HCC mice. CONCLUSION: Via modulating the miR-155/Tim-3 pathway, repression of NEAT1 restrained CD8+T cell apoptosis and enhanced the cytolysis activity against HCC, implying an effective target for improving the outcome of immunotherapy.