X射线照射对鼻咽癌细胞多药耐药基因表达影响初步研究

Impact of high dose X-ray irradiation on the expression of multidrug resistance gene CNE1 cells

目的 RT-PCR法研究累积高剂量X射线照射后多药耐药基因MDR1 mRNA表达随时间的变化趋势,并且探讨Bcl-2、MMP7与MDR1的关系.方法 选取人鼻咽鳞癌CNE1细胞系进行体外培养及X射线照射,累积剂量50 Gy.分别收集CNE1细胞和X射线照后得到的CNE1R细胞,利用MTT法检测CNE1、CNE1R细胞对顺铂的耐药性;RT-PCR技术检测MDR1 mRNA的表达.选取CNE1和MDR1 mRNA表达最高的一组CNE1R细胞检测Bcl-2、MMP7 mRNA的表达情况.结果 CNE1R细胞对顺铂产生耐药性.RT-PCR检测CNE1细胞MDR1 mRNA半定量灰度值为0.47±0.04,照射50 Gy后1、7、21、28、35、42、49 d的CNE1R细胞MDR1 mRNA半定量灰度值均高于CNE1细胞,分别为0.67±0.06（t=-5.44,P=0.003）、0.70±0.01（t=-5.90,P=0.002）、0.73±0.01（t=-6.45,P=0.001）、0.67±0.03（t=-3.97,P=0.011）、0.65±0.01（t=-4.43,P=0.007）、0.62±0.05（t=-2.64,P=0.046）、0.62±0.02（t=-3.34,P=0.021）.RT-PCR法检测CNE1细胞和CNE1R细胞中Bcl-2 mRNA表达半定量灰度值不同,分别为0.55±0.02和1.05±0.04（t=-9.93,P=0.000）;MMP7 mRNA表达半定量灰度值也不同,分别为0.51±0.01和0.82±0.02（t=-8.51,P=0.000）.结论 X射线累积照射50 Gy后CNE1R细胞内MDR1基因表达高于照前CNE1细胞,可能与Bcl-2、MMP7基因表达的同步变化有关.

Objective To invstigate the effect of high dose X-ray irradiation on the expression of multidrug resistance-1 （MDR1）, Bcl-2, MMP7 genes. Methods A nasopharyngeal carcinoma cell line,CNE1, were irradiated with a total dose of 50 Gy. The resistance to the cisplatin of CNE1 cells and the irradiated CNE1 （CNE1 R） cells was detected by MTT. mRNAs expression of MDR1 , Bcl-2 and MMP7 was measured by quantitative RT-PCR. Results The expression of MDR1 increased in CNE1 R cells. The semiquantitative A value of MDR1 mRNA was 0.47 ±0.04, and the value of CNE1R cells （1st, 7th, 21st,28th, 35th, 42nd and 49th days after irradiation） were 0.67 ± 0. 06 （t = -5.44, P = 0. 003） ,0.70 ± 0. 01（t=-5.90,P=0. 002）,0.73±0. 01（t= -6. 45,P=0. 001） ,0. 67 ± 0. 03 （t= -3.97,P=0.011）,0.65 ±0.01（t = -4.43,P=0. 007）,0. 62±0. 05（t= -2. 64,P=0.046） and 0.62 ±0.02（t = -3.34,P=0.021）, respectively. Bcl-2 mRNA expression were 0.55 ±0.02 and 1.05 ±0.04（t = -9.93,P=0. 000） and MMP7 mRNA expression were 0.51 ±0.01 and 0.82 ±0.02（t = -8.51,P=0.000） in CNE1and CNE1 R cells. Conclusions The MDR1 expression was increased after a total dose of50 Gy irradiation,which may be related to the synchronous change of Bcl-2 and MMP7 genes.