肿瘤源性热休克蛋白70激活肝癌射频消融术后肿瘤免疫反应及其对抗肿瘤作用影响的研究

Previous studies have shown that: hypoxia caused by transcatheter arterial embolization (TAE) can induce heat shock protein 70 (HSP70) expression in residual tumors; hyperpyrexia by radiofrequency thermal ablation (RFA) also can enhance HSP70 expression in residual tumors surround the ablation zone; the synergistic effect of hypoxia and hyperpyrexia generated by TAE combined with RFA (TAE+RFA) could induce HSP70 over-expression in residual tumors. Tumor-derived HSP70 were shown to play important roles in the initiation of antitumor immunity by activating the chemoattracted dendritic cells (DCs) and then inducing tumor-specific T-Cell responses..Our study will base on the results of above mentioned studies. Firstly, we establish the low expression of HSP70 in rabbit VX2 residual liver tumor model by RFA combined liposomal quercetin which had been proved to inhibit expression of HSP70 in residual tumors after the treatment of RFA. Secondly, we made different levels of HSP70 expression by liposomal quercetin, RFA, TAE+RFA and RFA combined liposomal quercetin treatments in rabbit VX2 liver tumor. Then, we observe the correlation of four levels of HSP70 in residual tumors and the number changes of DCs, CD4+T and CD8+T cells infiltration surrounding the residual tumors. We observe the relationship between four levels of HSP70 in residual tumors and the concentration of IFN-γ secreted by lymphocytes, tumor necrosis rate, tumor growth rate, tumor metastasis rate, and the apoptosis rate of residual tumor cells. At the end, we hope to provide new strategies for how to regulate anti-tumor immune response action after RFA and find new avenues for tumor immunotherapy.

栓塞肿瘤供血动脉（TAE）导致的缺氧，射频消融（RFA）产生热刺激，均能刺激残瘤组织热休克蛋白70（HSP70）表达增高； TAE联合RFA所致的缺氧协同热刺激可明显提高残瘤组织HSP70表达。肿瘤组织表达的HSP70能通过活化树突细胞(DCs)进而激活肿瘤特异性T细胞免疫。本项目拟在此基础上，选择一种能抑制RFA后残瘤组织内HSP70表达的药物--脂质体槲皮素，建立抑制RFA术后残瘤组织HSP70表达的兔VX2肝癌模型，观察低表达的HSP70能否使RFA术后产生的肿瘤免疫受抑制。再观察脂质体槲皮素、RFA、TAE+RFA及脂质体槲皮素联合RFA四种方法产生的不同表达量的HSP70与残瘤周边DCs、CD4+T、CD8+T细胞浸润，淋巴细胞IFN-γ分泌浓度，肿瘤坏死率、生长率、转移率、残瘤细胞的凋亡率等肿瘤免疫及抗肿瘤疗效指标的相关性。最终为RFA后调控肿瘤免疫治疗肝癌提供新策略。

我们前期研究已知射频消融（RFA）产生热刺激能提高残瘤组织HSP70表达，栓塞肿瘤供血动脉（TAE）联合RFA所致的缺氧协同能更高地刺激残瘤组织HSP70表达。本研究通过细胞实验、动物肿瘤实验证实RFA术前24小时静脉注入脂质体槲皮素(LQ)能抑制RFA后残瘤组织内HSP70表达。进而我们确立了脂质体槲皮素抑制RFA术后残瘤组织HSP70表达的兔VX2肝癌模型。通过假消融手术、RFA、TAE联合RFA及脂质体槲皮素联合RFA四种方法产生的不同表达量的HSP70，进而我们确立了正负调节消融术后残瘤细胞内HSP70表达的动物模型。本研究发现消融灶周边残瘤内CD4+T和CD8+T 细胞浸润数与残瘤细胞内HSP70表达成正负相关关系，肿瘤坏死率、生长率及残瘤细胞的凋亡率等抗肿瘤疗效指标等亦成正负相关性。综上结果，本研究为RFA后调控肿瘤免疫治疗肝癌提供新策略。本项目资助发表SCI收录论文6篇，中文论文2篇，实用新型专利2项。培养硕士生4名，其中3名已经取得硕士学位，1名在读。项目投入经费23万元，支出22.9899万元，各项支出基本与预算相符，剩余经费0.0101万元，剩余经费及自筹经费将用于本项目研究后续支出。