Expression of EBF3 in hepatocellular carcinoma and the effect of EBF3 overexpression on HepG2 cell proliferation

Abstract

Objective To investigate the expression and clinical significance of early B-cell factor 3 (EBF3) mRNA and protein in hepatocellular carcinoma(HCC) and the effect of EBF3 overexpression on HepG2 cell proliferation. Methods The expression levels of EBF3 mRNA in 20 pairs surgical specimens of HCC and their distant noncancerous tissues were detected by fluorescence quantitative real-time polymerase chain reaction(FQ-RT-PCR). Western blot was used to detect the expression levels of EBF3 protein in 5 pairs surgical specimens of HCC and distant noncancerous tissues. The fusion protein EBF3-EGFP was ex-pressed in HepG2 cells by transfection of pEGFP/EBF3 into the synchronized HepG2 cells using lipo-fectAMINE 2000 regent. Expression of EBF3-EGFP fusion protein was observed under the inverted fluores-cence microscope. S-phase fraction(SPF) and proliferating index(PI) were analyzed with flow cytometry (FCM). Results The ratio of EBF3 mRNA to β2 mRNA in HCC tissues was significantly higher than that in distant liver non-cancerous tissues(0.55 ±0.12 versus 0. 22 ± 0.23, t = 5.69, P < 0.001 ). EBF3 protein in nuclear extracts of HCC tissues was about 4 fold that in distant non-cancerous tissues (26.35 ±14.06 versus 7.86 ± 8.47, t = 2.52, P = 0.036). Fluorescence microscopy revealed that 24 h after trans-fection of pEGFP/EBF3 into hepatoma HepG2, the fluorescence of EBF3-EGFP fusion protein was mainly observed in the nucleus. After transfection for 24 h and 48 h, SPF and PI were markedly increased in HepG2 cells transfected by pEGFP/EBF3 as compared with that in pEGFP-N1 transfeeted cells. Conclusion The expression of EBF3 at both mRNA and protein levels was up-regulated in HCC tissues. EBF3 promotes HepG2 cells proliferation through DNA replication, effect of EBF3 in ttCC needs to be further investigated. Key words: Early B-cell factor 3 ; Liver neoplasm; FQ-RT-PCR; Western blot; Proliferation