缺氧对肝癌HepG2细胞内PPARα和HIF-1α表达的影响及机制探讨

The influence and mechanisms of hypoxia on PPARα and HIF-1α in HepG2

目的观察不同程度缺氧条件下,肝癌HepG2细胞内过氧化物酶体增殖物激活受体α(PPARα)和缺氧诱导因子1α(HIF-1α)的表达,及反义封闭HIF-1α后对PPARα表达的影响。方法HepG2细胞分为正常对照组(A组)、缺氧24 h组(B组)、缺氧48 h组(C组)、缺氧72 h组(D组)。观察各组的PPARα、HIF-1α蛋白和mRNA表达变化。再设计对照组(E组)、HIF-1α反义寡核苷酸组(F组)、HIF-1α正义寡核苷酸组(G组)、HIF-1α错义寡核苷酸组(H组),观察各组HIF-1α对PPARα的表达影响。结果正常对照组,PPARα和HIF-1α少量表达。随着缺氧时间延长,PPARα和HIF-1α的表达呈现逐渐升高,在缺氧24 h时,mRNA和蛋白开始增高,48 h增高明显,72 h达高峰。反义封闭HIF-1α后,PPARα表达明显下降。结论PPARα及HIF-1α的表达随肿瘤细胞缺氧信号的加强而增加,PPARα受HIF-1α的调控。

Objective To study the expressions of peroxisome proliferator activated receptor α（PPARα） and hypoxiainducible factor-1α（HIF-1α） during different hypoxia state in hepatic cancer cell HepG2, and to investigate the PPARα expression after antisense oligonucleotide HIF-1α blocking. Methods First, the hepatic cancer cells（HepG2） were divided into group A（control group）, group B（hypoxia 24 h group）, group C （hypoxia 48 h group）, group D（hypoxia 72 h group）. The mRNA and protein of PPARα and HIF-1α were detected by RT-PCR and Western-blot on different groups, Second, the hepatic cancer cells（HepG2） were divided into group E（ control group） ; group F（ antisense group） ; group G （ sense group） ; group H （ false- sense group）. The Influence of antisense oligonucleotide HIF-1α on PPARα were detected by RT-PCR and Western-blot. Results Comparing with group A, the mRNA and protein of PPARα and HIF-1α increased significantly on group B, and reached peak on group D. Inversely, the mRNA and protein of PPARα were decreased after antisense oligonuclei of HIF-1α on group F, comparing with group E, G and H. Conclusions The expressions of PPARα and HIF-1α are increased in hypoxia condition, and PPARα may be regulated by HIF-1α.