耐伊马替尼CML细胞来源外泌体递送转运miR-365传递耐药性质

Imatinib is the first-line drug of treating chronic myeloid leukemia(CML),and the emergence of drug resistance is an important reason for the CML progression and treatment failure, but the mechanism has not been fully elucidated. Our previous experiments found that the Imatinib resistant K562G –derived exosomes can promote K562 of imatinib resistance, the exosomes carried high concentrations of mir-365, biological information science analysis showed that the target gene contains Bax and other pro apoptotic gene. Accordingly, we propose the hypothesis that the imatinib resistant CML cells derived-exosomes can delivery and transport miR-365 to promote drug resistance. We try to confirm that K562G cells can release exosomes to promote drug resistance by laser confocal microscopy, flow cytometry, non-contact co culture experiments; and confirm that the resistance effect is induced by miR-365 delivered by exosomes from K562G cells by luciferase assays, overexpression and inhibition assay, RT-PCR, Western blot and other molecular biology experiments. Finally, we confirm the imatinib-resistant CML cells can release exosomes and reform tumor microenvironment to transform the resistance properties, and further explain the mechanism of drug resistance of CML and provide a theoretical basis to improve the CML therapy.

伊马替尼是治疗慢性粒细胞白血病（CML）的一线药物，其耐药的产生是CML进展及治疗失败的重要原因，但耐药机制尚未完全阐明。我们前期实验发现耐伊马替尼细胞K562G外泌体可促进K562对伊马替尼产生耐药,该外泌体携带高浓度miR-365，生物信息学分析显示其靶基因包含BAX等促凋亡基因。据此，我们提出“耐伊马替尼CML细胞通过外泌体递送转运miR-365促进耐药的发生”的假说。我们拟通过激光共聚焦显微镜检查、流式细胞术、非接触共培养等实验证实K562G通过释放外泌体促进耐药发生；通过荧光素酶实验、过表达及抑制实验、RT-PCR及蛋白印迹等分子生物学实验证实外泌体的促进耐药作用是通过其携带的miR-365下调K562相关促凋亡分子表达而实现的。最终证实耐伊马替尼CML可以通过释放外泌体对肿瘤微环境进行改造，为进一步阐述CML耐药机制及提高CML疗效提供理论基础。

伊马替尼是治疗慢性粒细胞白血病（CML）的一线药物，其耐药的产生是CML进展及治疗失败的重要原因，但耐药机制尚未完全阐明。本项目中我们通过分离及鉴定伊马替尼耐药 CML细胞来源外泌体,证实耐药CML细胞来源外泌体能被伊马替尼敏感CML细胞摄取,并且耐药CML外泌体可介导miR-365在伊马替尼耐药和敏感的慢粒细胞之间转移，同时外源性高表达miR-365在伊马替尼敏感的CML细胞中可降低化疗敏感性和凋亡。最终证实：伊马替尼耐药CML细胞能通过其分泌的外泌体传递耐药性至敏感CML细胞，这可能与外泌体介导传递高浓度的miR-365至敏感CML细胞有关。本课题的研究成果为探索慢性粒细胞白血病的耐药机制提供新思路，为进一步提高CML疗效提供理论基础。通过本课题资助，课题组共发表4篇SCI期刊论文，培养3名技术骨干和1名研究生。