摘要
目的:研究Egr-1基因的表达在放射诱导的细胞凋亡中的作用．方法:选择肝癌细胞系HepG2,SMMC-7721和正常肝细胞系HL-7702培养;培养细胞接受4Gy X射线照射;收获受照前和受照后1,2,4, 6,12和24 h的细胞,采用荧光定量PCR(FQ- PCR)检测0,1,2和4 h Egr-1基因的表达,采用流式细胞术(FCM)检测0,6,12和24 h细胞周期和细胞凋亡．结果:随HepG2,SMMC-7721和HL-7702在4GY X射线照射后1 h即诱导了Egr-1基因表达增高,4 h均未达峰值,分别为ΔEgrHepG2(12．9629±1．0649)、ΔEgr7702(0．0096±0．0008)和ΔEgr7721(0．0017±0．0003),HepG2显著高于HL-7702和SMMC-7721(P<0．01)．照射后6 h射线诱导的3株细胞凋亡均不明显,但在12 h均诱导了明显的细胞凋亡,而且HepG2(41．16％)和HL-7702(27．45％)已达峰值; SMMC-7721诱导的细胞凋亡水平较低,24 h仅为24．94％,且未达峰值．在射线诱导的细胞周期变化中,HepG2和SMMC-7721 S期的变化与细胞凋亡变化在6-12 h走势相反．结论:在HepG2,SMMC-7721和HL-7702细胞中,射线通过诱导Egr-1基因表达而诱导了细胞周期和细胞凋亡的变化;射线诱导的Egr-1基因表达水平可能与射线诱导的细胞凋亡成正相关;S期肿瘤细胞可能易发生射线诱导的细胞凋亡．
AIM： To study the relationship between radiation-induced apoptosis and the expression of early growth response-1 （Egr-1） gene in liver cancer cell lines. METHODS： The cultured cells （HepG2, SMMC-7721 and HL-7702） were irradiated at 4Gy X-radiation. The expression of Egr-1 gene was detected by fluorescent quantitative-polymerase chain reaction （FQ-PCR） before and 1, 2, 4, 6, 12, 24 h after irradiation. Cell cycle and apoptosis were detected by flow cytometry （FCM）.
RESULTS： The expression of Egr-1 was increased from 1 to 4 h after irradiation in the three kinds of cell lines HepG2, SMMC-7721 and HL-7702, and the highest expression was in HepG2 cells （△EgrHepG2 = 12.9629 ± 1.0649）, which was significantly higher than that in SMMC-7721 or HL-7702 cells （△Egr7721 = 0.0017 ± 0.0003, △Egr7702 = 0.0096 ± 0.0008, P 〈 0.01）. Radiation-induced apoptosis was not significant 6 h after irradiation in all the three cell lines, but it reached the peak value at 12 in HepG2 （41.16%） and HL-7702 cells （27.45%）. Radiation-induced apoptosis was still relatively low in SMMC-7721 cells at 24 h （24.94%）. Radiation-induced changes of S phase and apoptosis was opposite in the tendency from 6 to 12 h in HepG2 and SMMC-7721 cells. CONCLUSION： X-radiation may induce cell-cycle changes and cell apoptosis by up-regulation of Egr-1 gene expression, and radiation-induced apoptosis may be associated positively with Egr-1 expression level. HepG2 and SMMC-7721 cells of S phase might be susceptible to apoptosis after irradiation.
出处
《世界华人消化杂志》
CAS
北大核心
2006年第30期2923-2927,共5页
World Chinese Journal of Digestology
基金
黑龙江省科技计划攻关项目
No.GC03C606-4
