E1A基因对人肺腺癌细胞化疗敏感性的影响

Effects of E1A Gene on Chemosensitivity of Human Lung Adenocarcinoma Cells

目的：探讨Ｅ１Ａ基因对人肺腺癌细胞的化疗增敏作用。方法：通过脂质体介导将Ｅ１Ａ基因导入人肺腺癌细胞系Ａ－ｎｉｐ９７３，经Ｇ４１８筛选获得稳定表达Ｅ１Ａ的转染细胞（Ａｎｉｐ９７３－Ｅ１Ａ）。用不同浓度顺铂、泰素及ＶＰ１６等化疗药物处理细胞，观察Ｅ１Ａ基因对人肺腺癌细胞的化疗增敏作用。结果：Ａｎｉｐ９７３－Ｅ１Ａ细胞对顺铂、泰素的敏感性显著增加，顺铂的ＩＣ５０值减少了７倍，并且敏感性随时间的延长而增加。但对ＶＰ１６，Ｅ１Ａ基因的稳定表达在该细胞系未显示增敏作用。免疫细胞化学染色显示，Ｅ１Ａ基因抑制了ＨＥＲ－２／ｎｅｕ的表达。结论：Ｅ１Ａ基因能增加人肺腺癌细胞对顺铂、泰素等化疗药物的敏感性。该作用可能与Ｅ１Ａ基因抑制ＨＥＲ－２／ｎｅｕ的表达有关。为在恶性肿瘤治疗上化疗和基因治疗联合应用的可能性提供了实验依据。

Objective: To investigate the effects of adenovirus type 5 E1A gene (Ad5E1A) on chemosensitivity of human lung adenocaxcinoma cells. Methods: The recombinant pcDNA3-E1A, a mammalian-expressing vector was introduced into the A- nip973 cells with lipofectAMINE. The cells resistant G418 were selected. Dishes (24-well) were inoculated with Anip973,A- nip973-vect and Anip973-E1A cells. Subconfluent monolayers were beated with cisplatin, paclitaxel and VP16 for 24 h, respectively. Viability of the cells was quantitated with MTT method. Results: The sensitivity of Anip973-E1A cells to cytotoxic agents (cisplatin and paclitaxel) was dramaitcally increased.The IC50 values for cisplatin and paclitaxel were reduced to approximate 7- fold in Anip3-E1A cells as compared with Anip973-vect cells. For VP16, the sensitivity was not changed. Conclusion: The results demonstrated that E1A gene was capable of enhancing the sensitivity of human lung adenocarcinoma cells to cytotoxic agents (cisplatin and paclitaxel), and the increased sensitivity was associated with the reduction of p185 level, suggesting the possibility of using E1A gene combined with anticancer agents to improve tumor treatment.