5-Aza-CdR对人胃癌细胞株生物学行为及RASSF1A mRNA表达的影响

Effects of 5-Aza-2'-deoxycytidine on Human Gastric Carcinoma Cell Lines and the Expression of RASSF1A Gene

观察不同浓度的5-氮-2′-脱氧胞苷(5-Aza-CdR)对人胃癌细胞株BGC-823、SGC-7901、MKN-28生长及RASSF1A mRNA表达的影响。方法:分别以0．4μmol/L、1．6μmol/L、6．4μmol/L、25．6μmol/L、102．4μmol/L浓度的5-Aza-CdR处理人胃癌细胞株BGC-823、SGC-7901、MKN-28,MTT比色法测定72h时间段的吸光度值、计算抑制率,流式细胞仪检测5-Aza-CdR对胃癌细胞株生长周期及凋亡的影响,RT-PCR检测5-Aza-CdR处理前、后抑癌基因RASSF1A mRNA的表达。结果:5-Aza-CdR抑制体外培养人胃癌细胞株BGC-823、SGC-7901、MKN-28生长,呈浓度依赖性;5-Aza-CdR能有效诱导BGC-823、SGC-7901、MKN-28细胞凋亡;RT-PCR检测人胃癌细胞株SGC-7901、MKN-28无RASSF1A mRNA表达,经5-Aza-CdR处理后基因重新表达, BGC-823处理前后RASSF1A mRNA均有表达。结论:新型抑癌基因RASSF1A与胃癌的发生相关,5-Aza-CdR能抑制胃癌细胞株的增殖,并促进凋亡,其机制可能与RASSF1A基因的重新表达有关。

Objective： To investigate the effects of demethylafing agent 5-Aza-2＇-deoxycytidine （5-Aza-CdR） on the growth of gastric carcinoma cell lines and the expression of RASSFIA. Methods：Gastric carcinoma cell lines were treated with 0.4μmol/L, 1.6μmol/L, 6.4μmol/L, 25.6μmol/L, and 102.4μmol/L 5-Aza-CdR, respectively. MTT assay was used to examine the inhibitory rate through the absorbency of 72 h. The cell cycle and apoptosis were analyzed by flow cytometry. （FCM）. The expression of the tumor suppressor gene RASSF1A was detected by reverse transcription polymerase chain reaction （RT-PCR）. Results：5-Aza-CdR inhibited the proliferation of gastric carcinoma cell lines in a concentration-dependent manner （0.4-102.4μmol/L）. After 5-Aza-CdR treatment, the number of G0/G1 cells was increased, and 5-Aza-CdR blocked the cell cycle at G1 phase. The apoptotic rate was also increased significantly. RASSF1A gene was always expressed in the cell line BGC-823 whether treated with 5-Aza-CdR or not, but it was reactivated by 5-Aza-CdR in gastric cell lines SGC-7901 and MKN-28 not expressing RASSF1A. Conclusion：5-Aza-CdR can inhibit the growth, and promote the apoptosis of gastric carcinoma cell lines by eliminating the methylation status of RASSF1A promoter.