双磷酸盐逆转肺腺癌EGFR-TKI获得性耐药的作用及分子机制研究

Innovative treatment strategies are urgently needed to overcome therapeutic resistance to EGFR-TKI. In the prophase of our study, we proved that bisphosphonates can bring survival benefits to advanced NSCLC patients with EGFR mutations and treated with EGFR-TKI. Our basic study suggested that concomitant use of bisphosphonates(BPs) and EGFR-TKI can inhibit STAT3 protein phosphorylation and improve therapeutic efficacy to advanced NSCLC patients. Basic research further confirmed the cytotoxic effect of gefitinib was enhanced by co-incubation with BPs treatment double phosphate can increase in lung adenocarcinoma cancer cell toxicity. BPS can lower the expression of STAT3 and phosphorylation significantly and increase apoptosis and sensitivity of gefitinib treatment with EGFR-TKI resistance lung cancer cell lines. We speculate that BPs may improve the therapeutic effect of NSCLC through decreasing IL-6 signaling activation, reversing EMT and STAT3 activity. Using the methods of molecular biology, we aimed to investigate the relationship of Bps and EMT. In addition, we also want to authenticate that BPs can modulate the IL-6/JAK/STAT3 signaling pathway, reveal the molecular mechanisms underlying the ability of Bps to enhance sensitivity to EGFR-TKI and overcome EGFR-TKI resistance. This study can not only clarify theoretically the mechanisms of BPs reverse acquired drug resistance to EGFR-TKI in lung adenocarcinoma, but also provide a new therapeutic strategy to overcome TKI resistance.

EGFR-TKI的获得性耐药给肺癌的治疗带来了新的挑战，是一个亟待解决的临床问题。本课题组前期临床研究显示双磷酸盐能够为EGFR敏感突变的患者带来生存获益。基础研究进一步证实双磷酸盐能够增加吉非替尼对肺腺癌细胞的毒性，增强吉非替尼对肺癌耐药株的诱导凋亡作用，显著下调STAT3的表达及磷酸化，提高肺腺癌耐药株对EGFR-TKI对的敏感性。我们推测双磷酸盐增效及逆转TKI耐药作用可能与其下调IL-6信号，抑制EMT及STAT3的磷酸化有关。本研究采用分子生物学等方法，在前期工作的基础上，进一步研究双磷酸盐与EMT的关系，探究双磷酸盐对IL-6/JAK/STAT3信号通路的影响，阐明双磷酸盐增强EGFR-TKI疗效及逆转其获得性耐药的分子机制。本研究不仅能从理论上阐明双磷酸盐逆转肺腺癌EGFR-TKI获得性耐药的机制，而且能够为临床EGFR-TKI的耐药提供新的解决方案。

既往研究显示同时抑制JAK/STAT3信号通路和上皮间质转化可能会克服非小细胞肺癌细胞对吉非替尼的耐药性。唑来膦酸注射剂用于临床治疗和预防骨质疏松，高钙血症和骨转移相关的并发症。临床研究表明ZA可能发挥抗肿瘤作用并延迟非小细胞肺癌患者的疾病进展。在本研究中，我们进行体外和体内试验探究唑来膦酸联合吉非替尼是否可以通过抑制JAK/STAT3信号通路和上皮间质转化，恢复非小细胞肺癌细胞对吉非替尼的敏感性。结果表明，唑来膦酸可有效提高吉非替尼耐药细胞对吉非替尼的敏感性。唑来膦酸降低了H1975和HCC827GR细胞系中JAK/STAT3信号的激活并逆转了细胞的上皮间质转化。此外，在唑来膦酸预处理的吉非替尼耐药细胞系中IL 6抵消了其增敏作用，并恢复了细胞对吉非替尼的耐药性。最后，在裸鼠的移植瘤模型中，唑来膦酸与吉非替尼联合用药通过抑制JAK/STAT3信号通路和上皮间质转化，有效抑制了吉非替尼耐药癌细胞的生长。总之，唑来膦酸通过抑制JAK/STAT3信号通路和上皮间质转化重新恢复了吉非替尼对其耐药肺癌细胞的敏感性。唑来膦酸和吉非替尼的联合可用药可能是一种逆转吉非替尼耐药性并延长非小细胞肺癌患者生存期的治疗策略。

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