eIF5A1对非小细胞肺癌细胞系化疗药物敏感性的影响

摘要

目的：探讨 eIF5A1对非小细胞肺癌（non - small cell lung cancer，NSCLC）细胞系化疗药物敏感性的影响及可能的机制。方法：应用 RT - PCR 法检测不同 NSCLC 细胞系 eIF5A1 mRNA 表达水平。MTT 法检测其对吉西他滨的敏感性，并分析二者的关系。构建真核表达载体 pEGFP - C1- eIF5A1并通过脂质体介导法转染肺腺癌 LTEP - a -2细胞。荧光显微镜、RT - PCR 和 Western blot 方法评估转染效率。MTT 法检测转染后细胞化疗药物敏感性变化。流式细胞仪检测转染后细胞周期及凋亡变化。结果：肺鳞癌细胞系 eIF5A1 mRNA 表达水平及对吉西他滨的敏感性均显著高于肺腺癌细胞系（ P ＜0.001）。pEGFP - C1- eIF5A1转染eIF5A1表达水平最低的 LTEP - a -2细胞后 eIF5A1 mRNA 及蛋白表达水平显著升高（P ＜0.001）。与对照组细胞比较，eIF5A1转染组细胞对吉西他滨、顺铂、紫杉醇、多西紫杉醇的敏感性显著增加（P ＜0.001）。S 期和G2∕ M 期细胞比例显著增加（P ＜0.001）。在化疗药物作用下，细胞凋亡率显著增加（P ＜0.001）。结论：在非小细胞肺癌中上调 eIF5A1的表达可能增加细胞对化疗药物的敏感性，其机制可能与 eIF5A1高表达增强化疗药物的促凋亡作用及影响细胞周期分布有关。%Objective:To investigate the effect of eIF5A1 gene on chemosensitivity of human NSCLC cell lines and the possible mechanism. Methods:Expression levels of eIF5A1 mRNA in different NSCLC cell lines were measured by RT - PCR . The sensitivities to gemcitabine for cells were detected by MTT assay. The correlation between the a-bove two was analysized. The eukaryotic expression plasmid pEGFP - C1 - eIF5A1 was constructed and transfected in-to the LTEP - a - 2 cells by liposome transfection reagent. The transfection was proved effective by the fluorescence microscopy,RT - PCR and Western blot. MTT assay was used to investigate the effects of eIF5A1 overexpression on the drug sensitivities of LTEP - a - 2 cells. The change of apoptosis rate and cell cycle were detected by flow cytome-try(FCM). Results:Lung squamous cell lines had higher eIF5A1 expression levels and sensitvities to gemcitabine than adencarcinoma cell lines(P < 0. 001). eIF5A1 mRNA and protein expression levels of LTEP - a - 2 cell line with the lowest eIF5A1 expression level were significantly increased after transfection with pEGFP - C1 - eIF5A1(P< 0. 001). Compaired with the empty vector group or un - transfected group,the sestivities to cisplatin,gemcitabine, paclitaxel,docetaxel were significantly increased for eIF5A1 gene transfected group(P < 0. 001),inforced eIF5A1 ex-pression increased the cell cycle arrest in S and G2 ∕ M phase(P < 0. 001). With the treatment of chemotherapeutic a-gents,the cell apoptosis also significantly increased in the eIF5A1 gene transfected group(P < 0. 001). Conclusion:Overexpression of eIF5A1 in non - small cell lung cancer may increase the sensitivity of cells to chemotherapeutic a-gents. eIF5A1 may influence chemosensitivity of non - small cell lung cancer through promoting apoptosis - accelera-ting effects of chemotherapeutic agents and changing the cell cycle.