靶向干预肝星状细胞GARP/TGF-β1介导的肿瘤免疫抑制提高肝癌射频消融疗效的研究

Tumor residues and metastasis after radiofrequency ablation (RFA) are the key factors influencing the long-term survival of patients with hepatocellular carcinoma (HCC), lacking of effective treatment measures. Previous studies have demonstrated that RFA could enhance T cell-mediated antitumor immune response. However, adaptive immunosuppression in tumor microenvironment limited the antitumor immune effects of RFA. Recent researches showed that RFA could activate hepatic stellate cells (HSCs) around the ablation zone. Activated HSCs secrete a large number of TGF-beta 1, which can be activated by the interaction with GARP on the surface of HSCs, inducing the conversion of anti-tumor immune microenvironment after RFA to an adaptive immunosuppressive microenvironment. In present study, we focus on the intervention strategy of adaptive immunosuppression after RFA， and propose HSCs-GARP/TGF-β1 axis as the therapy target. Exosomes targeted GARP and packed with TGF-β1-siRNA were constructed and used to interrupt the HSCs-GARP/TGF- β1 axis, in order to block the formation of adaptive immunosuppressive microenvironment after RFA, which may enhance the anti-tumor immune response. This study is aim to provide a novel strategy to prevent HCC recurrence and metastasis after RFA.

肝癌射频消融（RFA）术后肿瘤残留和转移是影响患者预后的关键，尚缺乏有效的干预措施。研究证实RFA可增强T细胞的抗肿瘤杀伤效应，但肿瘤微环境中适应性免疫抑制的发生抑制了RFA的抗肿瘤免疫功能。最新研究表明肝癌RFA可激活消融区周围的肝星状细胞（HSCs），活化的HSCs能够分泌大量的TGF-β1并与HSCs自身表面的TGF-β1受体GARP结合进一步激活TGF-β1，诱导肝癌RFA后由抗肿瘤免疫微环境向适应性免疫抑制微环境转换。本项目针对肝癌RFA后产生适应性免疫抑制这一科学问题，提出以HSCs-GARP/TGF-β1为靶点，构建靶向HSCs表面GARP并装载TGF-β1-siRNA的外泌体，靶向干预HSCs-GARP/TGF-β1通路，阻断肝癌RFA术后由HSCs介导的适应性免疫抑制微环境的形成，增强抗肿瘤免疫反应，减少RFA术后肿瘤残留和转移，为提高RFA临床疗效提供新的思路和依据。

肝癌射频消融（RFA）术后肿瘤残留和转移是影响患者预后的关键，尚缺乏有效的干预措施。最新研究表明肝癌RFA可激活消融区周围的肝星状细胞（HSCs），活化的HSCs可能在肝癌消融术后复发和转移中起到重要的作用。本项目针对肝癌消融术后复发这一科学问题，提出以消融术后局部肿瘤微环境的改变为切入点，探索热刺激后的HSCs对肝癌细胞生物学的影响。通过基因芯片筛选出热刺激前后肝星状细胞LX-2表达显著差异的基因透明质酸酶2（Has2），通过体内外实验证实过 hyaluronidase 2 表达Has2的LX-2细胞能够促进肝癌细胞HepG2的侵袭、迁移及上皮-间充质转化（EMT），从而促进肿瘤的生长。本研究结果提示了针对肝星状细胞Has2靶点进行干预，可能减少肝癌射频消术后复发，为转化临床应用提供新的思路和依据。