外泌体穿梭miR-20b调控肿瘤相关巨噬细胞自噬及其M2极化促进宫颈癌细胞侵袭转移的机制研究

Tumor-associated macrophage (TAMs)-mediated invasion and metastasis is one of the most important factors affecting the prognosis of cervical cancer (CC); its mechanism however remains unclear. TCGA dataset-derived microRNA-chip and our preliminary data showed that not only exosomal shuttle miR-20b was tissue-specific miRNA, but also corrected with metastasis from CC. The objectives of this project are 1) to further explore the expression of exosome miR-20b in TAMs derived from different human macrophage cell lines co-cultured with CC cells conditioned medium; 2) to determine the relationship between autophagy/ polarization of TAMs and invasion and metastasis of CC cells, as wells as expression of miR-20b and TAMs-mediated invasion and metastasis of CC cells; 3) to identify Atg5 and LAMP-1 are target genes in the progress of invasion and metastasis of CC cells; 4)to elucidate molecular mechanism that exosomal shuttle miR-20b regulates the process of TAMs M2 polarization (M2-TAMs)-mediated invasion and metastasis by targeting Atg 5 and LAMP-1 on the levels of molecule, cell and animal in vivo; 5) to verify exosomal shuttle miR-20b is involved in the process of M2-TAMs-mediated invasion and metastasis through LAMP-1/Atg5-TRAF2-RelB/p52 pathway. In summary, the research of exosome miR-20b-TRAF2-RelB/p52-TAMs alternative activation pathway may contribute a novel strategy to invasion and metastasis treatment and new drug development in CC.

肿瘤相关巨噬细胞（TAMs）介导的侵袭转移是影响宫颈癌预后的重要因素，但具体研究机制不详。在前期miRNA芯片筛选出外泌体miR-20b在宫颈癌组织中特异性高表达的基础上及其与宫颈癌细胞转移正相关的线索，本项目拟以外泌体miR-20b为研究对象，进一步分析miR-20b在体外TAMs中表达水平，探索miR-20b及TAMs极化与宫颈癌细胞侵袭迁移的关系; 明确miR-20b靶向Atg5和LAMP-1参与TAMs M2极化（M2-TAMs），并从分子、细胞至动物水平深入研究miR-20b靶向自噬相关基因在M2-TAMs介导的宫颈癌细胞侵袭与转移发生过程中的分子机制，最后明确miR-20b与TRAF2-RelB/p52-TAMs替代激活通路的作用关系和参与宫颈癌细胞侵袭转移过程。miR-20b-TRAF2-RelB/p52-TAMs通路的研究将为宫颈癌细胞侵袭转移的治疗、药物研发提供新策略。

宫颈癌是女性最常见的恶性肿瘤之一，严重危害女性生命健康。侵袭和转移是影响宫颈癌预后的重要因素，然而分子机制至今仍不清楚。肿瘤相关巨噬细胞（TAMs）介导的侵袭转移是影响宫颈癌预后的重要因素，但具体研究机制不详。巨噬细胞根据刺激后功能分为经典激活的巨噬细胞（M1 型）和替代激活的巨噬细胞（M2型）。外泌体是近几年发现的在细胞与细胞间通讯中起关键作用的胞外基质成分，参与到免疫应答、自噬与凋亡、血管生成、炎症反应、肿瘤生成等生物学过程中。此外，肿瘤细胞通过递送外泌体与肿瘤微环境中的基质细胞相互作用，促进肿瘤细胞的上皮-间质间转化的发生、转移、耐药等。目前，对于肿瘤相关巨噬细胞（TAMs）及外泌体在宫颈癌侵袭和转移的研究尚少，并且结果并不完全一致。我们研究组在前期miRNA芯片筛选出外泌体miR-20b在宫颈癌组织中特异性高表达的基础上及其与宫颈癌细胞转移正相关的线索，本项目以外泌体miR-20b为研究对象，进一步分析miR-20b在体外TAMs中表达水平，结果发现肿瘤相关巨噬细胞（TAMs）中miR-20b表达明显升高，可通过宫颈癌外泌体转移至巨噬细胞，并与宫颈癌细胞的侵袭与转移相关；明确了miR-20b与其靶基因Atg5结合及明确结合位点；证实外泌体miR-20b与巨噬细胞M2型分化相关炎性因子表达水平相关；证实外泌体miR-20b通过靶向作用Atg5抑制自噬，从而抑制TRAF2-RelB/p52轴，诱导巨噬细胞M2极化，从而对宫颈癌细胞侵袭与转移产生影响。以此为宫颈癌细胞侵袭转移的治疗、药物研发提供新策略。