论文部分内容阅读
目的研究p73在苯并(a)芘[B(a)P]致人肺纤维细胞株MRC-5和人肺腺癌细胞株H1299(p53-null)周期阻滞中的作用。方法采用0(溶剂对照)、8、16、32、64和128μmol/L的B(a)P分别处理处于对数生长期的MRC-5和H1299细胞24h。采用MTT比色法检测两种细胞系的生长率,采用流式细胞术检测细胞周期各时相的细胞百分比,采用实时荧光定量PCR方法测定p53、p73、p21和Gadd45的mRNA表达水平。结果与溶剂对照组比较,8、16、32、64μmol/LB(a)P染毒组MRC-5细胞和H1299细胞的增殖活性均升高,差异有统计学意义(P<0.05或P<0.01)。16μmol/LB(a)P染毒组MRC-5细胞和32μmol/LB(a)P染毒组H1299细胞的增殖活性达到峰值,与溶剂对照组相比,分别增加了40%和30%。与溶剂对照组比较,8、16、32、64和128μmol/L的B(a)P染毒组MRC-5细胞的p53、p73和p21基因mRNA表达水平上升,差异均有统计学意义(P<0.05或P<0.01),细胞阻滞在G1期。与溶剂对照组比较,8μmol/L的B(a)P染毒组H1299细胞p73和p21基因mRNA表达的表达水平上升,差异均有统计学意义(P<0.05),细胞阻滞在G1期;但各处理组Gadd45基因的mRNA表达水平间比较,差异无统计学意义(P>0.05)。结论一定浓度B(a)P可通过p53介导引起MRC-5细胞周期G1期阻滞,而对于p53缺失的H1299细胞,其细胞周期G1期阻滞可能依赖于p73参与的细胞信号通路的调节。
Objective To investigate the role of p73 in the cycle arrest of human pulmonary fibroblast cell line MRC-5 and human lung adenocarcinoma cell line H1299 (p53-null) induced by benzo (a) pyrene [B (a) P]. Methods MRC-5 and H1299 cells in logarithmic growth phase were treated with 0 (solvent control), 8, 16, 32, 64 and 128 μmol / L B (a) P for 24 h, respectively. The growth rates of the two cell lines were detected by MTT assay. The percentage of cells in each phase of the cell cycle was detected by flow cytometry. The mRNA expression levels of p53, p73, p21 and Gadd45 were determined by real-time fluorescence quantitative PCR. Results Compared with the solvent control group, the proliferative activity of MRC-5 cells and H1299 cells in 8, 16, 32 and 64μmol / L (a) P groups were significantly increased, the difference was statistically significant (P <0.05 or P <0.01 ). The proliferative activity of MRC-5 cells exposed to 16μmol / L (a) P and poisoned cells treated with 32μmol / L (a) P reached the peak values, increased by 40% and 30% respectively compared with the solvent control group. Compared with the solvent control group, the mRNA expression levels of p53, p73 and p21 in MRC-5 cells of 8, 16, 32, 64 and 128μmol / L B (a) P groups increased significantly, with significant difference <0.05 or P <0.01), cell arrest in G1 phase. Compared with the solvent control group, the expression levels of p73 and p21 gene mRNA in H1299 cells treated with 8μmol / L B (a) P were significantly increased (P <0.05), and the cells arrested in G1 phase. However, there was no significant difference in mRNA expression level of Gadd45 among all treatment groups (P> 0.05). Conclusion A certain concentration of B (a) P can induce G1 phase arrest in MRC-5 cells through p53-mediated cell cycle arrest. However, arrest of cell cycle G1 phase in p53-deficient H1299 cells may depend on the regulation of cell signaling pathway involved in p73 .