RNA干扰RelB基因对小鼠RM-1前列腺癌细胞株放射敏感性的影响及其机制

目的:探讨RNA干扰RelB基因对鼠RM-1前列腺癌细胞株放射敏感性的影响及其机制。方法:利用靶向RelB基因的慢病毒载体(pLentilox-sh-RelB),脂质体介导转染RM-1细胞后进行放射(2,4,6,和8Gy剂量)处理培养,分别采用RT-PCR、Western印迹法及流式细胞术等方法检测RelB的mRNA和蛋白表达,锰超氧化物歧化酶(Mn-SOD)活力及细胞放射敏感性的变化。结果:转染后放射处理培养,siRelB-RM-1组RelB的mRNA和蛋白表达水平明显低于siVector-RM-1组和nontrans-RM-1组(P<0.05);放射处理培养后siRelB-RM-1组细胞凋亡百分率明显高于siVector-RM-1组和nontrans-RM-1组(P<0.05);培养后siRelB-RM-1组细胞Mn-SOD活力下降,放射增敏比为5.13。结论:RNA干扰RelB基因可增强鼠RM-1前列腺癌细胞株放射后的放射敏感性,其机制可能与RNA干扰RelB基因,抑制细胞增殖,降低Mn-SOD活力和诱导凋亡有关。

RNA interference of RelB enhances the radiosensitivity of prostate cancer cell line RM-1 in mice

Objective: To investigate the effect of RNA interference of the RelB gene on the radiosensitivity of the mouse prostate cancer cell line RM-1 and its mechanism.Methods: We constructed RelB siRNA-expressing lentiviral vectors targeting the RelB gene with the molecular biological technique,and determined the expressions of RelB mRNA and protein on radiation after transfection with siRelB mediated by liposome using RT-PCR and Western blot,respectively.We also detected the apoptosis of RM-1 cells by FCM assay and their radiosensitivity by clonogenic assay.Results: The expressions of RelB mRNA and protein were significantly lower in the RM-1 cells than in the control and negative interference groups after transfection with RelB siRNA(P<0.05),while the apoptosis of RM-1 cells remarkably higher in the siRelB-RM-1 than in the control group after radiation treatment(P<0.05).The activity of Mn-SOD was markedly decreased(P<0.05),and the radiosensitization rate of the RM-1 cells in the RelB-RM-1 group was 5.13 after radiation treatment.Conclusion: RNA interference of the RelB gene could enhance the radiosensitivity of the mouse prostate cancer cell line RM-1,which might be associated with its inhibition of Mn-SOD expression and induction of cell apoptosis.