Role of hepatitis B virus X protein in regulating LIM and SH3 protein 1 (LASP-1) expression to mediate proliferation and migration of hepatoma cells

Hongjuan You,Fanyun Kong,Lina Hu,Renxian Tang,Weidong Du,Peng Zhang,Kuiyang Zheng

doi:10.1186/1743-422x-9-163

Hongjuan You, Fanyun Kong + Show 5 more

Open Access

https://doi.org/10.1186/1743-422x-9-163

Copy DOI

Journal: Virology Journal	Publication Date: Aug 16, 2012
Citations: 37	License type: CC BY 2.0

Affiliation: Xuzhou Medical College, University Hospital Ulm

Abstract

BackgroundHepatitis B virus X protein (HBx) has been shown to be responsible for the development of hepatocellular carcinoma (HCC) caused by Hepatitis B virus infection. However, its potential effect on the progression of hepatocellular carcinoma remains yet unclear. LIM and SH3 protein 1 (LASP-1), a focal adhesion protein, is expressed in an up-regulation manner in the HCC tissues. LASP-1 plays an important role in the regulation of proliferation and migration of HCC. In this study, we investigated the effect of LASP-1 involved in HBx-related tumor progression.MethodsLASP-1 levels in the HBx stable transfected HepG2 and Huh-7 cells were detected by RT-PCR and western blot analysis. The cellular localization of LASP-1 was assessed by immunofluorescence analysis. The activity of phosphatidylinositol 3-kinase (PI3-K) pathway was demonstrated by western blot assay. The HBx-expressing cells were transfected with specific small interference RNA (siRNA) against LASP-1. The proliferation and migration ability of cells were evaluated by cell viability assay and plate clone formation assay. The migration ability of cells was detected by transwell assay and wound healing assay.ResultsRT-PCR and western blot analysis indicated the expression of LASP-1 was increased in the stable HBx-expressing cells compared with the control cells. Immunofluorescence study revealed that the distributions of LASP-1 in HepG2-HBX cells were mainly in pseudopods and the cytoplasm while they were mainly localized in the cytoplasm of HepG2-Mock cells. The cellular localizations of LASP-1 in Huh-7-HBX cells were in the perinuclear fractions while they were mainly localized in the cytoplasm of Huh-7-Mock cells. The upregulation of LASP-1 was inhibited after treatment with LY294002, PI3-K pathway inhibitor. Overexpression of LASP-1 in the stable HBx-expressing cells enhanced the proliferation and migration ability of hepatocellular cells. siRNA-mediated LASP-1 knowdown in the stable HBx-expressing cells significantly suppressed hepatocellular cells proliferation and migration.ConclusionsThese results demonstrated that HBx could upregulate LASP-1 through PI3-K pathway to promote the proliferation and migration of hepatoma cells.

Highlights

Hepatitis B virus X protein (HBx) has been shown to be responsible for the development of hepatocellular carcinoma (HCC) caused by Hepatitis B virus infection
The expression of HBx induced morphologic changes of hepatoma cells and resulted in more multinucleate cells To investigate the potential ability of HBx in regulating LIM and SH3 protein 1 (LASP-1) expression, we transfected HBx-expressing plasmid pcDNA3.1-X into two human hepatocarcinoma cell lines, HepG2 cells and Huh-7 cells, and established two stable HBx-expressing cell lines, HepG2-HBX and Huh7-HBX
The results indicated that HBx could modify the phenotype and confer the migration ability of hepatocarcinoma cells (Figure 2B)

Summary

Introduction

Hepatitis B virus X protein (HBx) has been shown to be responsible for the development of hepatocellular carcinoma (HCC) caused by Hepatitis B virus infection. We investigated the effect of LASP-1 involved in HBx-related tumor progression. Studies have identified that HBx could stimulate HBV replication and interfere with cell cycle progression through interacting with many cellular regulatory proteins including p53, AP-1, the cyclic AMP response element-binding protein (CREB) and activating transcription factor 2 (ATF2) [2]. Some studies have demonstrated that HBx contributes to invasion and metastasis of hepatocellular carcinoma by inducing a migratory phenotype in transformed cells in a CD44-dependent manner and altering ECM adhesion properties of HBx-bearing cell by interfering with the expression of the fibronectin receptor, α5β1 [9,10]. HBx plays an important role in tumor spreading by enhancing cellular migration through upregulation of MMP-9, MMP-3, MT1-MMP and COX-2 [11,12,13,14]

Methods

Results

Conclusion