低氧对人胃癌细胞p53 异构体表达的影响及意义

Effect of hypoxia on expression of p53 isoforms and its significance in human gastric cancer cell

摘要:

目的 探讨p53 异构体在缺氧诱导的胃癌细胞中的作用及分子机制，为筛选胃癌精准治疗靶分子， 以及临床诊断和治疗提供新思路。方法 将不同浓度的二氯化钴CoCl2（25、50 及100μmol/L）作用于人胃 癌细胞株SGC7901 模拟低氧微环境，采用CCK-8 法检测细胞活力；实时荧光定量聚合酶链反应检测HIF- 1α mRNA 的表达；巢式逆转录多聚酶链反应（nRT-PCR）检测Δ133p53α、Δ133p53β、Δ133p53γ 及 p53βmRNA 的表达；应用划痕愈合实验检测胃癌细胞迁移能力。结果 不同浓度的CoCl2 作用于人胃癌细 胞24 h，细胞活力随浓度的升高而增强（P <0.05）；不同浓度的CoCl2 对人胃癌细胞HIF-1α、Δ133p53α、 Δ133p53β 及p53β mRNA 的表达有影响（P <0.05）；25μmol/L 和50μmol/L CoCl2 组与对照组比 较，差异无统计学意义（P >0.05）；100μmol/L CoCl2 组与对照组比较，差异有统计学意义（P <0.05），且 100μmol/L CoCl2 组HIF-1α、Δ133p53α 及Δ133p53β mRNA 相对表达量高于对照组，而p53β mRNA 相对表达量低于对照组。对照组与实验组未检测到Δ133p53γ mRNA 的表达。划痕愈合实验结果显示缺氧 的胃癌细胞迁移速度加快。结论 低氧微环境可促进胃癌细胞生长、迁移，但缺氧需达到一定程度。p53 异 构体Δ133p53α、Δ133p53β 高表达及p53β 低表达可能是胃癌发生、发展的重要因素。

Abstract:

Objective To investigate the role and molecular mechanism of p53 isoforms in hypoxia induced gastric cancer cells, and to provide new ideas for screening target molecules of gastric cancer and for clinical diagnosis and treatment. Methods Different concentrations of cobalt dichloride (25, 50, 100μmol/L) were applied to human gastric cancer cell line SGC7901 to simulate hypoxia microenvironment. The cell viability of human gastric cancer cell was tested by cell proliferation/toxicity testing kit (CCK-8 kit). The mRNA expressions of HIF-1α was detected by real-time polymerase chain reaction and the mRNA expression of Δ133p53α, Δ133p53β, Δ133p53γ and p53β were detected by nested reverse transcription PCR. The migration ability of gastric cancer cells was detected by scratch healing experiment. Results After different concentrations of cobalt dichloride treated human gastric cancer cells for 24 h, CCK-8 assay showed that the cell viability was increased with the increasing of concentrations (P < 0.05). PCR showed that the mRNA expression of HIF-1α, Δ133p53α, Δ133p53β, p53β was affected by different concentrations of cobalt dichloride in human gastric cancer cells (P < 0.05). But, 25μmol/L and 50μmol/L groups were not significantly different compared with the control group (P > 0.05). The expression of HIF-1α, Δ133p53α and Δ133p53β in 100μmol/L group was significantly higher than that in the control group (P < 0.05), and the trend of p53β was contrary. No Δ133p53γ was detected in all control groups and experimental groups. The results of scratch healing experiment showed that the migration rate of anoxic gastric cancer cells was significantly faster than that in the control group. Conclusions Hypoxia microenvironment can promote the growth and migration of gastric cancer cells, but hypoxia should reach a certain degree. High expression of Δ133p53α, Δ133p53β and low expression of p53β may be the key factors in the development of gastric cancer.