腺病毒载体介导的HBx表达对HepG2细胞中PPARγ定位的影响

Effects of HBx on localization of PPARγ in HepG2 cell line

目的检测外源基因HBx转入HepG2细胞后对PPARγ表达定量及定位的影响。方法以HBx重组腺病毒感染HepG2细胞,分别用RT-PCR和总蛋白Western blot检测PPARγ表达量的改变,免疫细胞化学检测其定位改变,Western blot分别检测细胞质和细胞核中PPARγ蛋白量的表达改变,MTT法检测HBx对曲格列酮抑制HepG2增殖效率的影响。结果外源基因HBx转入HepG2细胞后,RT-PCR、总蛋白Western blot显示PPARγ表达差异无统计学意义(P>0.05),免疫细胞化学及细胞质和细胞核中PPARγ蛋白检测提示PPARγ在细胞核内表达降低而在细胞质中出现积聚,曲格列酮对HepG2细胞增殖的抑制效率降低(P<0.05)。结论外源基因HBx对HepG2细胞中PPARγ的表达量无明显影响,但影响其向核内转移。HBx降低曲格列酮对HepG2细胞增殖的抑制效率。

Objective Hepatitis B virus （HBV）-encoded X （HBx） contributes to the development of hepatocellular carcinoma （HCC）. Peroxisome proliferator activated receptor （PPARγ） highly expressed in some hepatoma cell lines. We tend to investigate the possible relationship between HBx and PPARγ in the development of hepatic cancer. Methods PPARγof HepG2 cells traysinfected with recombinant HBx adenovirus, with blank vector and without transfection was detected by RT-PCR for its mRNA level, Western blot for its protein level and immunocytochemistry for its localization. The effect of HBx on the inhibition of HepG2 cell growth by troglitazone, the ligand of PPARγ, was measured by MTT assay. Results The localization of PPARγ in HepG2 cells infected with HBx adenovirus was changed, increasing in cytoplasm and decreasing in cellular nucleus, while the expressions of PPARγmRNA and protein were not significantly changed, compared with those in HepG2 cells or HepG2 cells transfected with blank vector. The inhibitory effects of troglitazone on HepG2 cell growth weakened when HepG2 cells were infected with HBx adenovirus. Conclusion HBx may affect the localization of PPARγ, but not the quantity of PPARγexpression. HBx decreases the inhibition ratio of troglitazone on HepG2 cell growth.