RNA干扰mdr1对尤文氏肉瘤细胞放射敏感性的影响

目的探讨利用RNA干扰(RNA interfering,RNAi)技术抑制多药耐药基因1(multidrug resistance gene1,mdr1基因)对尤文氏肉瘤细胞放射敏感性的影响。方法设立空白组、脂质体组(仅加入等量脂质体)、mdr1RNA干扰组作对照,用RT-PCR检测尤文氏肉瘤细胞转染shRNA前后mdr1的表达水平变化。用集落形成试验检测各实验组照射后人尤文氏肉瘤细胞株的集落形成率。AO/EB荧光检测法检测细胞凋亡率的变化。流式细胞仪测定P-gp的表达。结果mdr1基因的shRNA能够有效抑制mdr1基因的表达。经过RNAi的放射治疗组,其集落形成率较对照组明显下降,MGMT的表达也下调,差异有统计学统计学意义(P<0.05)。结论 RNAi技术抑制mdr1的表达,降低了尤文氏肉瘤细胞的放射抗性,其辐射增敏作用可能与抑制mdr1基因表达后P-gp的表达下调有关。

The effects of RNA interference to inhibiting mdr1 on radiosensitivity in Ewing's sarcoma line Hele

Objective To investigate the inhibitory effects of RNAi expression vector of mdr1 gene on radiosensitivity in Hele cell of Ewing’s sarcoma.Methods RNAi expression vector for mdr1 gene was constructed and transfected to Hele cell of Ewing’s sarcoma with liposomes.RT-PCR and flow cytometer detects effect that it to mRNA and protein expression of mdr1 Cellular response to irradiation was evaluated by the colony froming test Apoptosis was observed by fluorescent staining.P-gp protein espressionwas determined by immunohistochemical staining.Results RNAi group could significantly decrease the proliferation rate and downregulate the expression of mdr1 of irradiated Ewing’s sarcoma.Conclusion Mdr1 oligodexynucleotides sensitize the cell of Ewing’s sarcoma to ionizing irradiation through decreasing the expression of mdr1,which might be related to decreasing the expression of P-gp.