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背景与目的:研究p63与p73的mRNA表达与BaP致人肺腺癌细胞(H1299)和人支气管上皮细胞(16HBE)DNA损伤的关系。材料与方法:分别用不同浓度BaP(8、16、32、64和128μmol/L)处理H1299和16HBE两种细胞,在4 h和12 h时,使用相应的生化检测试剂盒分别测定细胞裂解液中MDA的水平和SOD、GSH-Px的活性,用qRT-PCR方法测定处理后细胞的p53、p63、p73、mdm2和mdm4的mRNA水平;用Comet实验评价细胞DNA损伤程度。结果:16、32和64μmol/L BaP处理4 h时,两种细胞MDA水平显著性升高,SOD和GSH-Px活性显著性下降(P<0.05)。用BaP处理H1299和16HBE细胞4 h和12 h时均观察到DNA损伤随浓度增加而加重,且呈剂量-效应关系(P<0.01),mdm2、mdm4mRNA表达水平升高(P<0.01)。不过仅在12 h时p53基因mRNA表达水平较对照组显著增加(P<0.01)。在4 h和12 h时点,仅在H1299细胞的p63和p73mRNA表达增加(P<0.05)。结论:在BaP致p53缺失的H1299细胞的DNA损伤中,BaP可能通过不依赖p53信号通路激活了p63和p73 mRNA的表达。
BACKGROUND & AIM: To investigate the relationship between the mRNA expression of p63 and p73 and the DNA damage induced by BaP in human lung adenocarcinoma cells (H1299) and human bronchial epithelial cells (16HBE). MATERIALS AND METHODS: H1299 and 16HBE cells were treated with different concentrations of BaP (8, 16, 32, 64 and 128μmol / L) respectively. Cell lysates were determined at 4 h and 12 h using the corresponding biochemical detection kit The levels of MDA and SOD, GSH-Px were determined. The mRNA levels of p53, p63, p73, mdm2 and mdm4 were determined by qRT-PCR. The degree of DNA damage was assessed by Comet assay. Results: The MDA levels of both cells increased significantly and the activities of SOD and GSH-Px decreased significantly (P <0.05) at 16 h, 32 h and 64 μmol / L BaP treatment. DNA damage was observed at 4 h and 12 h after treated with BaP for 4 h and 12 h, respectively. The DNA damage increased with the increase of concentration, and the dose-effect relationship (P <0.01) and the expression of mdm2 and mdm4 mRNA increased (P <0.01). However, the expression of p53 mRNA was significantly increased only at 12 h (P <0.01). At 4 h and 12 h, p63 and p73 mRNA expression increased only in H1299 cells (P <0.05). CONCLUSION: BaP may activate the expression of p63 and p73 mRNA by p53-independent p53 signaling pathway in BaP-induced p53-deficient H1299 cells.