外泌体miRNA-222-3p介导前列腺癌雄激素非依赖转化及其机制研究

Prostate cancer is the most common male reproductive system tumor, although androgen deprivation therapy could improve the condition of most patients, but after a period of remission, most patients eventually develop to poor prognosis of androgen independent prostate cancer, the mortality rate is very high, but its transformation mechanism is unclear. In our preliminary work, we found that exosomes (Exos) secreted by AIPC cell line LNCaP-AI can promote LNCaP growth activity in androgen-free complete medium, and enhance the migration and invasion ability of LNCaP cells; further study found that the expression of miRNA-222-3p was significantly higher in LNCaP-AI exosomes than that of LNCaP exosomes; moreover, overexpression of miRNA-222-3p can significantly promote the proliferation ability of LNCaP. Based on the preliminary data, in this study, we will further construct miRNA-222-3p overexpression/silencing cell and exosome models, and investigate the effect of Exos-miRNA-222-3p mediated AIPC transformation on prostate cancer cell proliferation, migration and invasion. This proposal is hopefully to clarify the significance and functions of Exos-miRNA-222-3p in AIPC transformation, and elucidate the regulatory mechanism of Exos-miRNA-222-3p-mediated AIPC transformation，this study is hopefully to provide new research ideas for the pathogenesis of AIPC.

前列腺癌是男性生殖系统最常见肿瘤，去势治疗后易转化为雄激素非依赖性前列腺癌（AIPC），致死率高，但其转化机制尚不明确。我们前期研究发现，AIPC细胞株LNCaP-AI的外泌体可促进LNCaP在无雄激素培养基中的增殖和迁移侵袭能力，LNCaP-AI外泌体中miRNA-222-3p明显高表达，且miRNA-222-3p过表达可显著促进LNCaP生长，现有实验结果强烈提示外泌体miRNA-222-3p在AIPC转化中扮演重要角色。在前期研究结果基础上，我们拟构建miRNA-222-3p过表达/敲低的细胞和外泌体模型，重点关注外泌体miRNA-222-3p介导AIPC转化过程中对前列腺癌细胞生长和迁移侵袭能力的影响，明确外泌体miRNA-222-3p在AIPC转化中的意义和具体作用，进而阐明外泌体miRNA-222-3p介导AIPC转化的调控机制，本课题有望为AIPC发病机制研究提供新思路。

前列腺癌是男性生殖系统最常见肿瘤，去势治疗后易转化为雄激素非依赖性前列腺癌（AIPC），致死率高。有研究表明外泌体（Exosome, Exos）内含有大量miRNAs，它们可以在局部发挥作用，也可以进入血液循环在远端部位发生作用，但Exos-miRNA在AIPC转化中的作用和机制尚不明确。我们通过miRNA高通量测序对LNCaP、LNCaP-AI和PC3的miRNA表达谱进行分析，发现miRNA-222-3p在AIPC细胞株中异常高表达，而且miRNA-222-3p过表达可促进PCa细胞增殖和迁移侵袭能力；进一步研究发现LNCaP-AI细胞的外泌体可促进LNCaP细胞增殖活性及迁移侵袭能力，并且可增强LNCaP细胞对去雄激素培养的耐受性；利用免疫荧光和细胞共培养技术，我们证实AIPC细胞来源的外泌体可携带miR-222-3p 转运到ADPC细胞，进而促进ADPC细胞向AIPC细胞转化；我们通过miRNA靶基因生物信息预测，并利用荧光素酶报告基因检测、qPCR进一步发现和证实MIDN是miRNA-222-3p的一个靶mRNA，此外，我们在细胞和动物水平证实Exos-miR-222-3p可靶向MIDN激活mTOR信号通路介导AIPC转化；我们进一步发现CRPC病人外周血Exos-miR-222-3p的表达显著高于ADPC病人，而且CRPC病人外周血来源的外泌体可显著增强LNCaP细胞的生长活性。这些结果表明Exos-miR-222-3p有望作为AIPC的潜在诊断标志物和治疗靶点。