间充质干细胞外泌体传递miR-21在肾癌发生发展中的作用及其分子机制

Mesenchymal stem cells (MSCs) play an important role in renal cell carcinoma, but its mechanism is still not clarified. It has been reported that exosomes/extracelular vesicles derived from MSCs (MSC-EVs) regulate cell growth and metastasis in various cancersby transferringextracellular molecular...In our previous study，we demonstrated that MSC-EVs enhanced ccRCC cell invasion and their angiogenic capacity by a co-culture system of MSCs and clear cell renal cell carcinoma (ccRCC) cell lines (ACHN and 786-O). Moreover, MiR-21 in MSC-EVs was significantly upregulated by culture-supernatants derived from renal cancer cells. These data suggest that miR-21 in MSC-EVs plays a positive role in cell invasion and angiogenesis of renal cell carcinoma...In the present study, in vivo, an orthotopic mouse model of renal cancer will be established to assess the role of MSC-EVs on tumor growth, metastasis and angiogenesis of renal cell carcinoma. In vitro, miR-21 in MSCs will be overexpressed or knocked down to study the role of MSC-EVs-miR-21 in renal cancer cells. The RT-PCR, Western blot, luciferase reporter assay and chromosome immunopreciation will be taken to identify miR-21’s target genes and explore the relationship between MSC-EVs-miR-21 and renal cell carcinoma metastasis/angiogenesis associated signal pathway, such as STAT3, VEGF, and IL-8. The project is valuable to further clarify the molecular mechanisms of renal cell carcinoma, which may provide new clues for the diagnosis and treatment of renal cell carcinoma.

肿瘤组织中的间充质干细胞在肿瘤的发生发展过程中具有非常重要的作用，其分子机制尚未明了。研究表明，间充质干细胞外泌体（MSC-EVs）可通过传递细胞间分子信号，参与肿瘤的发生、发展与转移。我们的前期结果显示，MSC-EVs可促进肾癌细胞的侵袭和血管形成；并且MSCs-EVs内miR-21显著高表达。我们推测MSCs-EVs内miR-21的高表达可能与肾癌细胞的发生发展相关。本项目将建立原位肾细胞癌小鼠模型，进一步确定MSC-EVs在肿瘤生长、迁移及血管生成过程中的作用；通过miR-21过表达或RNA干扰技术，探讨MSC-EVs内miR-21对肾癌细胞生物学行为的影响；采用Western blot、荧光素酶活性分析和免疫共沉淀等方法，确定miR-21靶基因，明确miR-21促进肾癌发生发展的信号通路。上述研究，有望进一步阐明肾癌发生发展的分子机制，并将为肾癌的诊断和治疗提供新的思路。

背景与目的：肿瘤组织中的间充质干细胞（MSCs）在肿瘤的发生发展过程中具有非常重要的作用，其分子机制尚未明了。肿瘤的发生和转移与肿瘤所处的微环境密切相关。肿瘤细胞不仅通过自分泌和旁分泌，改变自身生存和发展的条件，促进肿瘤的生长和发展；并且它还可通过与其他细胞相互联系，传递分子信号，为肿瘤的生长和发展提供有利的微环境。其中间充质干细胞(Mesenchymal Stem Cells, MSCs)及其分泌物参与肿瘤的生长、转移和血管生成，但其分子机制尚未明了。本研究将以肾细胞癌为研究对象，探讨间充质干细胞外泌体中miRNAs在肿瘤发生发展中的作用及其分子机制。.方法与结果：在本研究中，通过Transwell实验和血管形成实验，我们发现MSCs通过分泌外泌体可促进肾癌细胞的迁移，并促进血管的生成；我们通过将肾癌细胞系和间充质干细胞共培养体系模拟肾癌微环境，观察发现MSC-EVs可促进对肾癌细胞的迁移和血管形成能力。通过miRNAs PCR array，我们检测了间充质干细胞外泌体中miRNAs的表达水平。结果显示，与肾癌细胞共培养后，间充质干细胞外泌体中miRNAs的水平显著上调或显著下调，其中miR-21水平显著升高。采用miR-21过表达技术，我们发现miR-21可促进EMT相关分子Snail 1和Vimentin的蛋白表达水平，抑制E-cadherin的表达，进而促进肾癌细胞的迁移能力。.结论与意义：间充质干细胞外泌体及miR-21可通过促进EMT相关分子表达促进肾癌细胞的浸润迁移能力及肿瘤血管形成能力，上述研究进一步揭示了肾细胞癌发生发展的分子机制，具并为肾癌的早期诊断及靶标治疗提供了科学依据。