射频消融在小肝癌治疗中已取得接近手术切除的总体生存效果，但较高的局部复发率迫切需要深入探索并适当干预。肿瘤和微环境间有效通信对残癌发生发展作用巨大。外泌体作为细胞间通信有效载体参与了肿瘤进展。前期研究发现热应激状态下肝癌细胞分泌的表达有热休克蛋白（HSPs）的外泌体数量增加，其所包含的miRNA表达谱亦变化显著，且有靶向癌旁巨噬细胞（Mφ）特性。体内实验提示热应激下分泌的外泌体能显著增加肝癌细胞的肝内成瘤和肺转移。沉默热休克因子1（HSF1）表达后热应激下外泌体数量减少，表达的HSPs显著降低，对Mφ的调节能力明显减弱。下一步将着力探讨HSF1调节外泌体数量和功能的机制，HSPs在外泌体靶向Mφ中的作用和相应受体鉴定，确认外泌体中哪种miRNA抑制Mφ中的抑癌基因表达，进而导致细胞因子谱表达向有利于肝癌发展的方向转变。寻找针对关键环节给予联合抑制减少射频消融术后复发的方法。

Since early 1990,radiofrequency ablation (RFA) has been widely used to treat liver tumor and developed rapidly. For small hepatocellular carcinoma, (HCC), randomized control trials indicated that RFA yielded similar long-term survival as compared to resection. However, the residual cancer rate and recurrence rate remain high after RFA, Even after curative RFA, residual cancer could be detected in 3%-52% of patients and recurrence rate has been reported up to 53%-81%. It is widely reported that tumor associated microenvironment plays the key role in the process of hepatocellular carcinoma (HCC) initiation and metastasis. However, the role of tumor associated microenvironment on the recurrece of HCC after RFA are fewly reported. Increasing evidences suggest that exosomes have emerged as a novel mode of intercellular communication. In our previously study, we found and reported that high peritumoral macrophage density and heat shock factor 1 (HSF1), which correlated with large tumor size, presence of intrahepatic metastasis, and high TNM stage, were independent prognostic factors for both overall survival and time to recurrence. Notably, serum exosome in HCC patients was found increased sharply after RFA therapy. .. Exosomes have been shown to act as shuttles between cells by transmitting signals. In addition to lipids,nucleic acids and proteins, double-stranded DNA, mRNA and miRNA have also been detected in exosomes. In vitro study showed that under heat stress, the exsome increased significantly with high HSP90 expression, which can be inhibited when the expression of HSF1 was knocked down. In vitro and in vivo study both suggested that the exosome secreted by HCC cells under heat stress have more opportunities to contact and fusion with macrophage. .，and the cytokine secretion, such as TGFβ, increased sharply. In pilot study, the expression of HSF1 in peritumoral liver tissue of nude mice with orthotopic xenograft HCC after RFA therapy. The level of HSP90 in nude serum increased sharply. It is very interested that the macrophage in peritumoral liver tissue increased obviously after RFA treated. It is reported HSF1 facilitates malignant transformation, cancer cell survival and proliferation in model systems. Based on our data and reported studies, we presented that HSF1 and downstream key molecules are the important elemants for the reconstruct of microenvironment, which in favor of HCC growth and metastasis. In further study, we will adopted Mass Spectrometry laser confocal fluorescence microscopy, flow cytometry, chromatin immunoprecipitation, co-immunoprecipitation, to verified the mechanism why HSF1 increases exosome secretion and tageted to macrophage, the role of HSPs in the exosome targeted to macrophage, which kind of miRNA play the key role of exosome to regulate tumor suppressor gene of macrophage.With nude mice orthotopic xenograft HCC receiving RFA treatment, we explore the role of inhibitor of HSPs, the inhibitor of miRNA, and macrophage specific cytotoxic drug, on the recurrence after RFA treatment, exploring the possible methods to decrease the recurrence rate and increase overall survival.