PDLIM5调控Hippo通路影响肺癌EGFR-TKI耐药的分子机制研究

Primary and acquired EGFR-TKI resistance significantly limits its use in clinical practice. Recent researches showed that Hippo pathway effector YAP was upregulated in TKI resistant cell lines, which could reduce TKI sensitivity. However, its mechanism remains unknown. In addition, the mechanism of YAP upregulation during the development of TKI resistance has not been reported yet. Our results showed that PDLIM5 was upregulated in erlotinib resistant cell line. PDLIM5 inhibited LATS1 and YAP phosphorylation, upregulated YAP protein, maintain mitochondrial potential and promoted glycolysis and glutamine metabolism. We hypothesized that PDLIM5 inhibits YAP phosphorylation through its LIM domain which could interact with Hippo component. YAP activates transcription of Bcl-xL, Drp-1, GLUT3 and GLUL which promote cell metabolism, maintain mitochondrial potential, inhibit ROS production and reduce TKI sensitivity. We intend to bidirectionally modulate PDLIM5/YAP expression with construction of PDLIM5 mutant plasmid containing different domains. The aim of this study was to elucidate the mechanism of PDLIM5/YAP induced TKI resistance and to provide important theoretical and experimental basis for TKI sensitization and prediction of resistance.

EGFR-TKI的原发和继发性耐药已成为其在肺癌治疗中应用的瓶颈。最新的研究发现Hippo关键因子YAP在TKI耐药细胞中过表达并且可以减弱肺癌细胞对TKI的敏感性，但机制尚不十分清楚。YAP在耐药细胞中上调的机制目前尚无相关报道。我们前期的研究发现PDLIM5在厄洛替尼耐药细胞中表达上调，并且可以抑制LATS1和YAP磷酸化，增加YAP蛋白表达，维持线粒体功能，促进糖酵解和谷氨酰胺代谢。结合文献我们推测PDLIM5通过其LIM结构域与Hippo通路成员相互作用，抑制YAP磷酸化降解促进其入核激活Bcl-xL、Drp1、GLUT3和GLUL等基因的转录，从而发挥上述生物学功能并降低TKI敏感性。我们拟通过双向调控PDLIM5/YAP、构建不同结构域的PDLIM5突变体，阐明PDLIM5和YAP介导TKI耐药的分子机制，为临床上肺癌TKI靶向治疗增敏和耐药预测提供重要理论基础和实验依据。

EGFR-TKI的原发和继发性耐药已成为其在肺癌治疗中应用的瓶颈。最新的研究发现Hippo关键因子YAP在TKI耐药细胞中过表达并且可以减弱肺癌细胞对TKI的敏感性，但机制尚不十分清楚。YAP在耐药细胞中上调的机制目前尚无相关报道。我们研究发现PDLIM5在厄洛替尼耐药细胞中表达上调，并且可以抑制LATS1和YAP磷酸化，增加YAP蛋白表达，维持线粒体功能，促进糖酵解和谷氨酰胺代谢。我们发现PDLIM5抑制YAP磷酸化降解促进其入核激活Bcl-xL、Drp1、GLUT1等基因的转录，从而发挥上述生物学功能并降低TKI敏感性。本研究为临床上肺癌TKI靶向治疗增敏和耐药预测提供重要理论基础和实验依据。本研究发表相关论文7篇。