YAP介导套细胞淋巴瘤对伊布替尼耐药的分子机制研究

Ibrutinib, as the representative of B cell signaling pathway inhibitor, is the most important advance in the treatment of mantle cell lymphoma(MCL) in recent years. However, virtually all of the MCL patients will experience treatment failure eventually, due to drug resistance. Therefore, the study on the mechanism of ibrutinib resistance and its reversal strategy is critical for improve the overall survival of MCL patients. Our previous study found that YAP was highly expressed in MCL patients, especially in relapse and ibrutinib resistant patients. Further study demonstrated that inhibited the expression of YAP would result in increasing sensitivity of ibrutnib and inhibiting the excitation of NF-κb signaling pathway and autophagy. However, the exact mechanisms remain unclear. So the purpose of the present project is to further validate the correlation between the expression level of YAP and the response to treatment, prognosis and drug resistance of MCL patients in a larger scale. Through in vitro and in vivo MCL cell line model, we will clarify the relationship between YAP and ibrutinib resistance and further elucidate the molecular mechanisms of how YAP involves in ibrutinib resistance. This project will provide novel insights into prognosis evaluation and the resistance reversal strategies on drug resistance of MCL.

以伊布替尼为代表的B细胞受体信号通路抑制剂是近年套细胞淋巴瘤（MCL）治疗最重要的进展。但多数患者会对药物产生耐药而导致治疗失败。因此对伊布替尼耐药机制的探讨和其逆转策略的研究对提高MCL整体治疗尤为重要。我们前期研究发现YAP在MCL尤其是复发及伊布替尼耐药患者中高表达，抑制YAP的表达可明显增加伊布替尼的敏感性。功能实验发现干扰YAP可明显抑制NF-κb信号通路及细胞自噬的活化。提示YAP可能通过活化NF-κb信号通路及细胞自噬参与MCL对伊布替尼耐药，但具体分子机制尚不明确。本课题拟进一步扩大临床样本验证YAP表达水平与MCL患者临床治疗反应、预后及伊布替尼耐药的相关性；通过MCL细胞系模型的体内和体外研究，明确YAP对伊布替尼耐药的影响并进一步阐明YAP介导MCL对伊布替尼耐药的具体分子机制，为MCL的预后评估、耐药逆转策略提供新的科学依据。

套细胞淋巴瘤（MCL）是一类异质性较强的血液系统恶性肿瘤，多数患者不可治愈，复发难治不可避免。伊布替尼是目前MCL重要的治疗药物，但是仍有1/3的患者对MCL原发或者继发耐药，耐药患者预后极差。Hippo信号通路是调节细胞的增殖、迁移和维持细胞的干性关键的信号通路。且既往研究显示Hippo信号通路关键分子YAP可能参与耐药。但是，关于Hippo信号通路与MCL之间的关系尚无相关研究。本研究通过RT-PCR、Western blot、免疫荧光等检测MCL中YAP的表达。通过sh-RNA敲除YAP或使用维替芬（VP）抑制YAP的功能进一步评估了影响YAP的表达对MCL发生发展及对伊布替尼药物敏感性的影响。研究发现在MCL中存在Hippo信号通路关键分子YAP的活化，干扰YAP可明显抑制MCL细胞系的增殖，促进凋亡，使细胞发生G0/G1期阻滞。此外，信号通路分析发现敲除YAP可以明显抑制与MCL发病密切相关的信号通路，如BCR、PI3K-AKT和细胞周期等信号通路活化。另外，药物敏感性研究显示，抑制YAP或者抑制NF-kb信号通路可明显抑制MCL细胞自噬从而增加伊布替尼的药物敏感性。上述研究结果均提示YAP可能参与MCL的发生发展及耐药。本项目通过MCL细胞系模型的体内和体外研究，明确YAP对伊布替尼耐药的影响并进一步阐明YAP介导MCL对伊替尼耐药的具体分子机制，为MCL的预后评估、耐药逆转策略提供新的科学依据，具有重要的临床价值及应用前景。