Polo样激酶1抑制剂在奥希替尼耐药的非小细胞肺癌细胞中的作用

The effect of PLK1 inhibitor in osimertinib resistant non-small cell lung carcinoma cells

目的:研究Polo样激酶1(PLK1)抑制剂在奥希替尼耐药的非小细胞肺癌(NSCLC)细胞中的作用及其合用奥希替尼的抗肿瘤效果。方法:利用药物浓度递增法构建对奥希替尼耐药的NCI-H1975细胞模型;在耐药细胞上合用肿瘤经典通路抑制剂库化合物与奥希替尼,筛选与奥希替尼存在协同作用的化合物;利用基因集富集分析考察奥希替尼耐药通路;利用磺酰罗丹明B染色法考察PLK1抑制剂对奥希替尼耐药细胞的抑制作用及其合用奥希替尼的抗肿瘤作用。结果:成功建立奥希替尼耐药细胞模型(耐药指数=43.45)。PLK1抑制剂GSK 461364和BI 2536与奥希替尼存在协同作用,与敏感细胞比较,奥希替尼耐药细胞中PLK1调控通路和细胞周期通路显著激活,且在接受奥希替尼治疗的表皮生长因子受体突变NSCLC患者队列中,PLK1信使RNA水平与患者的无进展生存期呈负相关(R=-0.62,P<0.05),证实NSCLC细胞中PLK1过度激活可能导致细胞对奥希替尼耐药。进一步体外实验发现,PLK1抑制剂伏拉塞替和GSK 461364对奥希替尼耐药细胞的半抑制浓度小于敏感细胞,相较于单用奥希替尼,PLK1抑制剂与奥希替尼合用可显著增强对耐药细胞的增殖抑制作用。结论:PLK1抑制剂与奥希替尼合用对奥希替尼耐药的NSCLC细胞的抑制作用更强,有可能用于奥希替尼耐药患者的干预和治疗。

Objective:To investigate the effects of PLK1 inhibitors on osimertinibresistant non-small cell lung carcinoma(NSCLC)cells and the anti-tumor effect combined with osimertinib.Methods:An osimertinib resistant NCI-H1975 cell line was induced by exposure to gradually increasing drug concentrations.Osimertinib-resistant cells were co-treated with compounds from classical tumor pathway inhibitor library and osimertinib to screen for compounds with synergistic effects with osimertinib.The Gene Set Enrichment Analysis(GSEA)was used to investigate the activated signaling pathways in osimertinib-resistant cells;sulforhodamine B(SRB)staining was used to investigate the effect of PLK1 inhibitors on osimertinib-resistant cells and the synergistic effect of PLK1 inhibitors combined with osimertinib.Results:Osimertinib-resistance in NCI-H1975 cell(resistance index=43.45)was successfully established.The PLK1 inhibitors GSK 461364 and BI 2536 had synergistic effect with osimertinib.Compared with osimertinib-sensitive cells,PLK1 regulatory pathway and cell cycle pathway were significantly activated in osimertinib-resistant cells.In NSCLC patients with epidermal growth factor receptor mutations treated with osimertinib,PLK1 mRNA levels were negatively correlated with progression free survival of patients(R=-0.62,P<0.05),indicating that excessive activation of PLK1 in NSCLC cells may cause cell resistant to osimertinib.Further in vitro experiments showed that IC50 of PLK1 inhibitors BI 6727 and GSK 461364 in osimertinib-resistant cells were lower than those in sensitive ones.Compared with the mono treatment of osimertinib,PLK1 inhibitors combined with osimertinib behaved significantly stronger effect on the proliferation of osimertinib-resistant cells.Conclusion:PLK1 inhibitors have a synergistic effect with osimertinib on osimertinib-resistant NSCLC cells which indicates that they may have potential clinical value in the treatment of NSCLC patients with osimertinib resistance.