5-氟尿嘧啶诱导直肠癌HR8348细胞凋亡作用的研究

目的　探讨 5 氟尿嘧啶 (5 fluorouracil ,5 FU )体外诱导直肠癌HR83 48细胞凋亡的作用及细胞凋亡与bcl 2、bcl xl、bax及 p5 3表达的关系。 方法　经 5 FU处理HR83 48细胞 2 4h后 ,用甲基绿 派若宁染色法和TUNEL法检测细胞凋亡情况 ,并用SP免疫组织化学法检测HR83 48细胞中bcl 2、bcl xl、bax和 p5 3的表达。 结果　HR83 48细胞经 5 FU作用 2 4h后 ,细胞凋亡指数 (AI)明显高于对照组 ,差异有显著性意义 (P<0 .0 1)。 5 FU作用不同时相bcl 2的表达评分结果与对照组比较差异均无显著性意义 ;不同时相bcl xl的表达评分结果与对照组比较稍降低 ;而bax的表达评分结果随时间延长明显增加 ,2 4h、3 6h的表达评分结果明显高于对照组 (P<0 .0 1) ,而 p5 3在 5 FU组和对照组各时相均未见表达。结论　 5 FU具有诱导HR83 48细胞凋亡的作用 ;5 FU可能通过上调bax的表达并改变bax/bcl xl的比值而诱导HR83 48细胞凋亡。

Induction of Apoptosis of Rectal Carcinoma Cell Line HR8348 by 5-Fluorouracil in Vitro

Objective To study the effect of 5-fluorouracil (5-FU) induced apoptosis of the rectal carcinoma cell line HR8348 in vitro and the relationship between apoptosis induced by 5-FU and the expression of bcl-2,bcl-xl,bax and p53,and to investigate the possible mechanism of apoptosis of rectal carcinoma cell line HR8348 induced by 5-FU. Methods After treatment with 5-FU for 24 h,the apoptotic index was detected by methyl green and pyronine Y staining and by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL).The bcl-2,bcl-xl,bax and p53 gene expression of HR8348 cells were examined by immunohistochemical method. Results After treatment with 5-FU,the apoptotic index of experiment group was significantly increased,there was significant difference as compared with the control.Exposed to 5-FU for 12 h,24 h and 36 h,the expression of bcl-2 of HR8348 cell line remained unchanged,but the expression of bcl-xl slightly diminished,while the expression of bax was remarkly increased,the expression of p53 was not detected in both experiment and control groups. Conclusion This results indicate that 5-FU may induce apoptosis of rectal carcinoma cell line HR8348 and the possible mechanism of apoptosis induction is through upregulation of bax expression and the change of bax to bcl-xl ratio.