Correlation of the expression of Noxa with hepatocellular carcinoma / 临床与实验病理学杂志

ABSTRACT

Purpose To explore the correlation of Noxa gene with clinical pathology and its effect on proliferation and apoptosis of HepG2 cells.Methods Noxa protein in 100 hepatocellular carcinoma tissues and 100 paracancerous tissues were detected by imnunohistochemical technique,clinicopathological parameters and follow-up data were statistically analyzed.The recombinant eukaryotic expression plasmid pIRES2-EGFP-Noxa was transiently transfected into HepG2 cells with lipofectamine.Both Noxa mRNA and protein were detected by RT-PCR and Western blot respectively.The inhibition of cell proliferation was evaluated by MTT assay.The cell apoptosis was detected by flow cytometry (FCM).Results Immunohistochemistry showed that in tumor tissue of hepatocellular carcinona the positive rate of Noxa protein expression was 50％,while it was 78％ in cancer adjacent normal mucosal tissue,with statistically significant difference (P ＜ 0.05).The expression of Noxa was related to TNM staging and the tumor differentiation.Exotic Noxa gene was expressed successfully in HepG2 cells after transfected with lipofectamine.The expression of Noxa mRNA and protein of HepG2 cells was significantly up-regulated after transfected 24 h,48 h and 72 h (P ＜ 0.05).MTT assay showed that the Noxa expression inhibited HepG2 cell proliferation in a time-dependent manner for 24 h,48 h and 72 h (P ＜ 0.05),which was significantly different from that of the control group (P ＜ 0.05).Apoptosis rate after transfected 24 h,48 h and 72 h was (15.5 ± 0.9)％,(24.6 ±0.8) ％ and (35.4 ±0.7) ％,respectively.There were significant difference between Noxa and the control group (P ＜ 0.05).Conclusion The expression of Noxa in hepatocellular carcinoma tissue is closely related to TNM stage and the tumor differentiation.Noxa gene overexpression is able to effectively inhibit the proliferation and promote the apoptosis of HepG2 cell line.