Background & Objective: It was reported that the hepatitis B virus X could inhibit the function of p53 and have contrary effects on p21(WAF1), a downstream gene of p53, but the mechanism is not clear up to now. So this study was designed to investigate HBx's effect on p21(WAF1) gene.
Methods: After co-transfection of sense or antisense wild type p53 gene (wtp53) with HBx into SMMC-7721 and HBx alone transfection into other hepatoma cell lines with different endogenous status of p53, we evaluated the luciferase expression level under the p21(WAF1) promoter by detecting the luciferase activity and alteration of cell cycle in these transfected cell lines by flow cytometry. Expressions of p53 and p21 (WAF1) in hepatoma cells after transfected with HBx were also estimated by Western blot analysis.
Results: The luciferase activity (1.007+/-0.098) in SMMC-7721 cells cotransfected with HBx and sense-wtp53 was higher than that in cells with wtp53 gene alone (0.490+/-0.012, P< 0.05), and also was depressed in the other experimental groups transfected with HBx (P< 0.05). Western blot analysis showed that after transfected with HBx, p53 expression was elevated in all hepatoma cell lines with different endogenous status of p53, and the expression of p21(WAF1) and luciferase activity under the p21(WAF1) promoter (0.053+/-0.010 vs. 0.094+/-0.013, P< 0.05) were both decreased in SMMC-7721 cells with low expression of p53, but relatively increased in HepG2 cell line with high expression of p53 (1.252+/-0.052 vs. 0.767+/-0.031, P< 0.05). Flow cytometry showed that fewer SMMC-7721 (42.31%) and Hep3B (36.96%) cells were arrested in G(0)/G(1) phase in transiently transfected HBx groups than in the control groups (47.10% and 42.90%), which was the opposite case in HepG2 cell line (63.62% vs. 57.42%). Moreover, after stably transfected with pcDNA3HBx, HepG2 cells reduced in G(0)/G(1) phase in compared with the control group (57.31% vs 61.49%).
Conclusion: HBx may not only increase the expression of p21(WAF1) by introducing the accumulation of p53 in cytoplasm but also inhibit the transcriptional activity of p21(WAF1) promoter in a p53-independent manner.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Molecular Biological Mechanisms of Action of Chrysophanol in Hepatic Stellate Cells Activated by Hepatic B Virus X Based on Network Pharmacology.
Intervirology
December 2024
Department of Research, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan.
Introduction: Chrysophanol (Cho) is a natural anthraquinone with biological effects such as inducing ferroptosis and anticancer activity. The hepatitis B virus X protein (HBx) is essential for HBV replication. We aimed to identify the key pathways in HBx-induced hepatic stellate cell (HSC) activation and to characterize the potential mechanisms of action of Cho against liver fibrosis.
View Article and Find Full Text PDFExploring the tolerable region for HiBiT tag insertion in the hepatitis B virus genome.
mSphere
October 2024
Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan.
Unlabelled: A cell culture system that allows the reproduction of the hepatitis B virus (HBV) life cycle is indispensable to exploring novel anti-HBV agents. To establish the screening system for anti-HBV agents, we exploited the high affinity and bright luminescence (HiBiT) tag and comprehensively explored the regions in the HBV genome where the HiBiT tag could be inserted. The plasmids for the HiBiT-tagged HBV molecular clones with a 1.
View Article and Find Full Text PDFBackground & Aims: Circulating HBV RNAs have been proposed as a biomarker that reflects the transcriptional activity of covalently closed circular DNA (cccDNA) and may help to evaluate HBV treatment activity. Different research assays have been proposed and, although two PCR-based research use only investigational assays have been developed, the lack of standardized protocols represents an important limitation. Here we have designed and generated a stable clonal cell line producing an RNA-based standard for the calibration of PCR-based circulating HBV RNA assays.
View Article and Find Full Text PDFHepatitis B Virus X Protein Induces Expression Changes of miR-21, miR-22, miR-122, miR-132, and miR-222 in Huh-7 Cell Line.
Arch Razi Inst
February 2024
Infectious diseases research center, Golestan University of Medical Sciences, Gorgan, Iran.
Hepatitis B virus (HBV) X protein (HBx) plays a key role in hepatocellular carcinoma (HCC). HBx may alter the expression of multiple microRNAs (miRs), which are important in hepatocarcinogenesis. This study aimed to investigate the importance of HBx protein in the expression of miR-21, miR-22, miR-122, miR-132, and miR-222.
View Article and Find Full Text PDFHBx integration in diffuse large B-cell lymphoma inhibits Caspase-3-PARP related apoptosis.
Tumour Virus Res
December 2024
Department of Clinical Laboratory, Fudan University Shanghai Cancer Center, Shanghai, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China. Electronic address:
Diffuse large B-cell lymphoma (DLBCL) is the most common pathological type of non-Hodgkin lymphoma, and is closely associated with hepatitis B virus (HBV) infection status and hepatitis B X (HBx) gene integration. This project investigated the cellular biological effects and molecular mechanisms responsible for lymphomagenesis and the progression of HBx integration in DLBCL. The data showed that clinical DLBCL cells demonstrated HBx integration, and the sequencing analysis of integrated sites validated HBx integration in the constructed HBx-transfected cells.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!