摘要
目的研究顺铂作用于p53野生型AGS、p53突变型MGC-803、SGC-7901 3种胃癌细胞株后,引起细胞凋亡及p53下游基因表达的变化,探讨其发生机制。方法采用流式细胞技术(FCM)检测不同浓度顺铂(0、1、2μg/mL)作用24 h后AGS、MGC-803、SGC-7901 3种胃癌细胞株,细胞周期和凋亡率的变化;RT-PCR法检测上述不同浓度顺铂分别作用于3种胃癌细胞株,p53下游基因p21、bax、puma、bcl-2、bcl-xl表达的变化。结果FCM显示,顺铂可引起3种细胞细胞周期发生改变:S+G2期比例均明显升高,同时3种细胞的凋亡率均明显增多(P<0.01);RT-PCR结果显示,AGS细胞的p53、bax、p21表达均随顺铂剂量的增加而增加(P<0.05),puma变化不明显(P>0.05);bcl-2、bcl-xl的表达随顺铂剂量的增加而降低(P<0.05)。MGC-803、SGC-7901细胞的bcl-2、bcl-xl表达均随顺铂剂量的增加而降低(P<0.05),而bax、p21、puma的表达变化不明显。结论在p53突变细胞株中,DNA损伤可诱导细胞周期阻滞和细胞凋亡,凋亡调控因子的表达也发生改变。其机制可能与p53突变的具体位点有关,亦可能与p53非依赖性途径的信号传递有关。
Objective To study the effects of cisplatin on the expression of downstream signal factors of the p53 pathway in gastile cancer cell lines with wild-type p53 （AGS cell） or mutated p53 .（MC, C-803, SGC-7901 cells）, and to explore its mechanism. Methods AGS, MGC-803 and SGC-7901 cells were treated with different concentrations of cisplatin （0μg/mL, 1μg/mL and 2μg/mL） for 24 hours. （ 1 ） FCM was used to determine the percentage of cells in each cell cycle phase and the apeptosis rate. （2） Reverse transcription-pelymerase chain reaction （RT-PCR） was used to determine the expression changes of downstream signal factors of the p53 pathway including p21, bax, puma, bcl-2 and bcl-xl. Results （ 1 ） After treatment with cisplatin, the number of cells in phase S ＋ G2 was obviously increased in all three types of cells, and the apoptosis rate was also manifested （ P 〈 0.01）. （2） After cisplatin treatment, in AGS cells, p53, bax and p21 were increased in a dose-dependent fashion （ P 〈 0.05）, puma had no significant changes, while the expressions of bcl-2 and bcl-xl decreased with the increase of the cisplatin dose （ P 〈 0.05）, also in MGC-803 and SGC-7901 cells, the expressions of bcl-2 and bcl-xl were decreased with the increase of the concentration of cisplatin, while bax, p21 and puma had no significant changes. Conclusions In p53 mutated gastric cancer cells, the damage of DNA could still arrest the cell cycle phase and leads to apeptosis, with expression changes of apeptosis signal factors. This mechanism may be due to the specific mutated sites of p53 transmitting signals of DNA damages downward to apoptosis factors, or perhaps due to the p53 independent pathway that is not disturbed by p53 mutation.
出处
《山东大学学报（医学版）》
CAS
北大核心
2008年第5期478-480,484,共4页
Journal of Shandong University:Health Sciences
关键词
基因
p53
胃癌细胞
顺铂
Gene p53
Gastric cancer cell
Cisplatin
