miR-34a对裸鼠人肺癌移植瘤放射敏感性的影响

Effect of miR-34a on human lung cancer xenografts radiosensitivity in nude mice

目的探讨miR-34a对裸鼠人肺癌移植瘤放射敏感性的影响。方法培养人肺腺癌H1299细胞,对24只裸鼠建立人肺癌移植瘤模型,并分为4组:对照组(control)、MRX34组(MRX34)、放射线治疗组(RT)和MRX34+放射线治疗组(RT+MRX34),测定各组肿瘤体积在放射线治疗后随时间的变化,放疗结束后25d处死各组裸鼠,对各组肿瘤组织的RNA进行提取并测定miR-34a的浓度,蛋白免疫印迹法与免疫组化检测比较对照组与MRX34组的RAD51的表达。结果 MRX34注射后,miR-34a在肿瘤组织中成功表达;MRX34+放射线治疗组相比于其它3组,具有更好的肿瘤生长延缓作用;Western blot和免疫组化均显示MXR34组的RAD51表达较对照组明显下降,差异均有统计学意义(P<0.05)。结论 miR-34a的表达可以增加裸鼠人肺癌移植瘤的放射敏感性,其机制可能与抑制了RAD51的表达相关。

Objective To observe the expression of miR-34a on human lung cancer xenografts radiosensitivity in nude mice. Methods The human lung cancer model in nude mice were established with H1299 cell lines. The mice were randomly divided into control group （control）, MRX34 group （mrx34）, Radiation Therapy （RT） group and MRX34＋ Radiation Therapy group （RT＋ MRX34）. The volume of the tumors in each group after radiation therapy was measured. The mice were sacrificed after 25 days of radiation therapy, and tissues were harvested for total RNA extraction and evaluation of miR-34a levels. The expression of RAD51 of control group and MRX34 group were detected by western blotting and immunohistochemistry. Results Expression of miR-34a in tumor tissue with the injection of MRX34 was successful. Compared with the other three groups, tumor growth of MRX34＋ radiation therapy group delayed. Compared with control group, the expression of RadS1 of MXR34 group significantly decreased. Conclusion The expression of miR-34a increases the radiosensitivity of human lung cancer in nude mice, and its mechanism may be related to inhibiting the expression of RAD51.