吉非替尼通过自噬促进PC-9肺癌细胞凋亡的实验研究

Gefitinib improves apoptosis in lung adenocarcinoma cell line PC-9 through induction of autophagy

目的探讨自噬对吉非替尼(Gefitinib)诱导EGFR突变型NSCLC PC-9细胞凋亡的影响及机制。方法MTT法检测Gefitinib对PC-9细胞的生长抑制作用;AO染色观察经Gefitinib处理后PC-9细胞嗜酸性自噬泡(acidic vesicular organelles,AVOs)的变化情况;Western blot检测自噬标记物LC3、凋亡相关蛋白PARP、Caspase-3以及Akt/mTOR信号通路的表达;流式细胞术检测Gefitinib及Gefitinib联合自噬诱导剂Rapamycin作用下细胞凋亡情况。结果 MTT及流式细胞术显示Gefitinib呈剂量依赖性抑制PC-9细胞生长并促进其凋亡,AO染色后,经Gefitinib处理的PC-9细胞内可观察到红染的AVOs,Western blot显示Gefitinib能够诱导PC-9细胞自噬标记物LC3表达。Gefitinib联合Rapamycin显著增强Gefitinib对于PC-9细胞的杀伤作用,并且降低PC-9细胞中Akt/mTOR的磷酸化水平。结论 Gefitinib能够诱导PC-9细胞发生自噬,增强细胞自噬能够促进Gefitinib杀伤PC-9细胞的作用。

Objective To determine the effect and underlying mechanism of autophagy on the apoptosis in gefitinib-induced non-small cell lung cancer cell （NSCLC） line PC-9 with epidermal growth factor receptor （EGFR）-mutation. Methods MTT assay was applied to assess cell viability in PC-9 cells after gefitinib treatment. Acridine orange staining was used to detect the formation of acidic vesicular organelles （AVOs） after the treatment. Western blot analysis was used to determine the expression of autophagy marker LC3, apoptosis-related proteins PARP, Caspase-3 and cleaved Caspase-3, and signal pathway proteins Akt and mTOR. Flow cytometry was used to measure the apoptosis in presence or absence of autophagy inducer rapamycin. Results Gefitinib treatment inhibited cell growth and induced cell apoptosis in a dose-dependent manner in PC-9 cells shown by MTT assay and flow cytometry, enhanced autophagy for more AVOs formed by acridine orange staining, and significantly upregulated LC3. Gefitinib in combination with rapamycin promoted cytotoxic effect of gefitinib to PC-9 cells and down-regulated Akt/mTOR phosphorylation. Conclusion Gefitinib induces autophagy in PC-9 cells, and induction autophagy facilitates gefitinib-induced apoptosis.