肿瘤来源外泌体miR-6826-5p靶向肺成纤维细胞促进肾癌肺转移的机制研究

转移性肾癌五年生存率不到2%，肺是最常见的转移靶器官。肿瘤细胞源性外泌体在诱导靶器官微环境改变，促进肿瘤定植转移中的作用受到广泛关注。我们前期通过体内外实验和芯片筛选验证发现肾癌细胞通过分泌含有miR-6826-5p的外泌体，靶向活化肺成纤维细胞，明显增加其促炎癌因子（IL-1β、IL-8、TGF-β等）的分泌，诱导形成转移前灶进而促进肾癌肺转移。初步机制研究表明miR-6826-5p潜在靶基因在调控上述细胞因子分泌的NF-kB信号通路中明显富集。本项目拟进一步利用RNA pull-down等方法研究肾癌细胞外泌体miR-6826-5p对肺成纤维细胞NF-kB信号通路的调控作用，采用质谱分析等技术鉴定外泌体特异性识别肺成纤维细胞的关键膜蛋白及相互作用结构域，从而阐明肾癌细胞外泌体“驯化”肺成纤维细胞，促进肾癌肺转移的分子机制及器官靶向性成因，为肾癌肺转移的临床预警和治疗提供新的靶点。

The five-year survival rate of metastatic kidney cancer is less than 2%, and the lung is the most common target organ for its metastasis. The role of tumor cell-derived exosomes in inducing target organ microenvironment changes and promoting tumor colonization and metastasis has received widespread attention. We verified in vivo and in vitro experiments and microarray screening that renal cancer cells secreted exosomes containing miR-6826-5p, activated lung fibroblasts, and significantly increased their inflammatory cancer factors (IL-1β, IL-8, TGF -β, etc.), induce the formation of pre-metastatic foci and promote lung metastasis of renal cancer. Preliminary mechanism studies indicate that miR-6826-5p potential target genes are significantly enriched in the NF-kB signaling pathway that regulates these cytokines. This project intends to further study the regulation of renal cancer cell exosomes miR-6826-5p on lung fibroblast NF-kB signaling pathway by using RNA pull down and expression profiling chips, and via mass spectrometry to identify key membrane proteins and domains for specific recognition and interaction between renal cancer cell-derived exosomes and lung fibroblasts, thereby elucidating the molecular mechanism of exosomes “domesticating” lung fibroblasts, promoting metastasis of renal cancer to lung, and its organ-preference, and thereby provide new targets for clinical warning and treatment of metastasis.