^(60)Co分割照射对鼻咽癌细胞生长增殖影响的观察

Effect of ^(60)Co gamma ray fractionated irradiation on growth and proliferation of nasopharyngeal carcinoma cell line CNE-2

目的:观察不同剂量60Coγ射线分割照射对鼻咽癌细胞株CNE-2细胞生长和细胞周期素(Cyclin)D1及增殖细胞核抗原(PC-NA)的影响。方法:0、2.0、4.0、6.0Gy60Coγ射线分割照射CNE-2细胞1次/d,共5d。四唑盐(MTT)比色法测定细胞抑制率;流式细胞术检测细胞周期。PCR检测PCNA和Cyclin D1表达水平。结果:2.0、4.0、6.0Gy60Coγ射线分割照射5次/5d后各组细胞生长抑制率分别为-17.05%、4.01%和15.52%;各照射组G1期细胞数量减少,S+G2/M期细胞数比例增多,χ2=16.53,P<0.001。0、2.0、4.0、6.0Gy60Coγ射线分割照射CNE-2细胞5次/5d,CyclinD1表达水平随照射分割剂量增加而下降直至不表达,P值分别为0.035、0.022和0.000。2.0Gy照射CNE-2细胞5次/5d,细胞生长增殖未受到抑制,PCNA表达无下调,P=0.471;4.0和6.0Gy照射CNE-2细胞5次/5d,细胞生长增殖受到抑制,PCNA表达下调,P值分别为0.028和0.016。结论:4.0、6.0Gy60Coγ射线分割照射5次/5d,细胞生长增殖受到抑制;2.0Gy照射5次/5d细胞生长增殖未受抑制;2.0、4.0、6.0Gy60Coγ射线分割照射5次/5d后,CyclinD1和PCNA表达受抑制。

OBJECTIVE：To observe the effects of 60Co gamma ray with different fractionated doses on the growth,cell cycle distribution,expression of Cyclin D1 and proliferating cell nuclear antigen（PCNA） of nasopharyngeal carcinoma cell line CNE-2. METHODS：CNE-2 cells were fractionated by irradiated with 0,2.0,4.0 and 6.0 Gy of 60Co gamma ray,respectively,one time per day for 5 days. MTT test and flow cytometry were used to detect the cell cycle. The expressions of Cyclin D1 and PCNA were detected by RT-PCR. RESULTS：The growth inhibiting ratios were -17.05%,4.01%,15.52% after 2.0,4.0 and 6.0 Gy of 60Co gamma ray fractionated irradiattion one time per day for 5 days,respectively. In all the radiation groups,the fraction of G1 phase cell decreased,and the S phase and G2/M phases cells increased （χ2=16.53,P0.001）. With the fractionated dose increased,the expression of Cyclin D1 decreased gradually until it cannot expressed （P values were 0.035,0.022 and 0.000 respectively）. In the 4.0 or 6.0 Gy fractionated radiation group,the cell growth inhibition occured and PCNA expression decreased in the CNE-2 cells （P values were 0.028 and 0.016 respectively）,but in the 2.0 Gy group,did not （P=0.471）. CONCLUSIONS：CNE-2 cell growth and proliferation are inhibited after 4.0 or 6.0 Gy of 60Co gamma ray fractionated radiation,but are not after 2.0 Gy radiation. The expression levels of Cyclin D1 and PCNA are suppressed after the irradiation.