epidermal-growth-factor and Hepatitis-B

Hepatocellular carcinoma (HCC) is a common solid malignant tumor occurring worldwide that leads to the third largest cause of death compared to other cancers. Genetic and environmental factors are involved in the pathogenesis of HCC. Epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) can stimulate the proliferation of epidermal and epithelial cells. The EGF signal pathway has a relationship with the growth of the embryo, tissue repairing, and tumorigenesis.. In this study, 416 patients with hepatitis B virus infection (HBV)-related HCC and 645 individuals who had never been infected with HBV of the Chinese Han population were enrolled. Eight single-nucleotide polymorphisms (SNPs), whose minor allele frequency >20% in the EGF and EGFR genes, were genotyped to examine their associations with hepatocarcinogenesis. Genotyping experiments were carried out using TaqMan.. There were significant differences in genotype distributions (p=0.005) and allele frequencies (p=0.001, odds ratio [OR]=1.43, 95% confidence interval [CI]=1.15-1.79) of rs11569017 in the EGF gene between the HCC and control groups. After binary logistic regression to determine independent factors for susceptibility to HCC under an additive model, rs11569017 was still independently associated with the susceptibility to HCC (p=0.021, OR=1.48, 95% CI=1.06-2.07), but no significant differences in other SNPs were found. Additionally, the haplotype T-G constructed by rs11569017 and rs4444903 of the EGF gene might increase the risk of HBV-related HCC (p=0.002, OR=1.44, 95% CI=1.15-1.82).. The rs11569017 T allele was associated with susceptibility to HBV-related HCC.

Topics: Adult; Aged; Alleles; Asian People; Carcinoma, Hepatocellular; China; Epidermal Growth Factor; ErbB Receptors; Female; Hepatitis B; Hepatitis B virus; Humans; Liver Neoplasms; Male; Middle Aged; Polymorphism, Single Nucleotide

Hepatocytes derived from human iPSCs are useful to study hepatitis B virus (HBV) infection, however infection efficiency is rather poor. In order to improve the efficiency of HBV infection to iPSC-derived hepatocytes, we set a co-culture of hepatocytes with liver non-parenchymal cells and found that liver sinusoidal endothelial cells (LSECs) enhanced HBV infection by secreting epidermal growth factor (EGF). While EGF receptor (EGFR) is known as a co-receptor for HBV, we found that EGF enhanced HBV infection at a low dose of EGF, whereas EGF at a high dose suppressed HBV infection. EGFR is internalized by clathrin-mediated endocytosis (CME) and clathrin-independent endocytosis (CIE) pathways depending on the dose of EGF. At a high dose of EGF, the endocytosed EGFR via CIE is degraded in the lysosome. This study is the first to provide evidence that HBV is endocytosed via CME and CIE pathways at a low and high dose of EGF, respectively. In conclusion, we developed an in vitro system of HBV infection using iPSC-derived liver cells, and show that EGF secreted from LSECs modulates HBV infection in a dose dependent manner.

Topics: Animals; Clathrin; Coculture Techniques; Endocytosis; Endothelial Cells; Epidermal Growth Factor; ErbB Receptors; Gene Knockdown Techniques; Hep G2 Cells; Hepatitis B; Hepatitis B virus; Hepatocytes; Humans; Induced Pluripotent Stem Cells; Liver; Mice; Mice, Inbred C57BL; Transfection; Virus Internalization

Earlier, we reported a highly statistically significant association between T-helper 1 (Th1) and Th2 cytokine genotypes and hepatocellular carcinoma (HCC) risk among natives of southern Guangxi, China, a hyperendemic region for HCC. Epidermal growth factor (EGF) plays a critical role in malignant transformation of hepatocytes and tumor progression. A polymorphism in the EGF gene (61A > G) results in elevation of EGF in liver tissues and blood. Epidemiological data are sparse on the possible association between EGF genetic polymorphism and HCC risk.. The EGF 61A > G polymorphism, multiple Th1 and Th2 genotypes, and environmental risk factors for HCC were determined on 117 HCC cases and 225 healthy control subjects among non-Asians of Los Angeles County, California, a low-risk population for HCC, and 250 HCC cases and 245 controls of southern Guangxi, China.. Following adjustment for all known or suspected HCC risk factors, non-Asians in Los Angeles who possessed at least one copy of the high activity 61*G allele of the EGF gene showed a statistically non-significant, 78% increased risk of HCC compared with those possessing the EGF A/A genotype. This EGF-HCC risk association significantly strengthened among heavy users of alcohol [odds ratio (OR) = 3.44, 95% confidence interval (CI) = 0.93-12.76, P = 0.065)], and among individuals carrying the high-risk Th1/Th2 genotypes for HCC (OR = 3.34, 95% CI = 1.24-9.03, P = 0.017). No association between EGF genotype and HCC risk was observed among Chinese in southern Guangxi, China.. Genetic polymorphism in the EGF gene resulting in elevated level of EGF, may contribute to HCC risk among low-risk non-Asians in Los Angeles.

Topics: Adult; Aged; Alcohol-Related Disorders; Carcinoma, Hepatocellular; Case-Control Studies; China; Epidermal Growth Factor; Female; Genotype; Hepatitis B; Hepatitis C; Humans; Incidence; Liver Neoplasms; Los Angeles; Male; Middle Aged; Polymorphism, Single Nucleotide; Prevalence; Risk Factors; Smoking; Th1 Cells; Th2 Cells

The hepatitis B virus (HBV) is a major causative agent of chronic liver disease and subsequent liver cirrhosis worldwide. The reduced sensitivity of virus-infected liver cells to apoptosis may play a role in the failure to remove virus-infected cells and eventually promote viral chronicity. The purpose of our study was to investigate whether survival factors induced during compensatory liver regeneration may protect hepatocytes against apoptosis. We evaluated the serum levels of hepatocyte growth factor (HGF) and epidermal growth factor (EGF) in HBV-infected patients and found significant increases in HGF and EGF in patients with active virus infection. In primary human hepatocytes we show that HGF and EGF have a protective effect against CD95-mediated apoptosis and cytotoxic T-cell killing. Simultaneous treatment with both regeneration factors enhanced the cytoprotective effect. The PI 3-K/Akt kinase inhibitor, wortmannin, and the STAT3 pathway inhibitor, Tyrphostin AG490, both effectively attenuated the cytoprotective effect of HGF and EGF. Furthermore, we show an EGF/HGF-dependent upregulation of beta(1)-integrin chains, increased adhesion to extracellular matrix and an increase in focal adhesions, suggesting outside-in signaling from the extracellular matrix as an additional cytoprotective mechanism. Our study demonstrates that HGF and EGF can interfere with CD95-mediated apoptosis and the action of cytotoxic T-cells through multiple mechanisms in human hepatocytes. Together our results argue that a survival mileau generated by activation of liver regeneration factors may be a risk factor for establishing viral persistence.

Topics: Apoptosis; Cell Adhesion; Cells, Cultured; Epidermal Growth Factor; Extracellular Matrix; fas Receptor; Hepatitis B; Hepatitis B virus; Hepatocyte Growth Factor; Hepatocytes; Humans; Immune System; Membrane Potentials; Signal Transduction; T-Lymphocytes, Cytotoxic

Hepatocyte-like cells induced from bone marrow mesenchymal stem cells (BMSCs) recover liver function in animal models with liver failure. Our initial findings revealed that human BMSCs improved liver function in hepatitis B patients with end stage liver disease. However, the susceptibility of BMSCs to HBV infection during induction toward hepatocytes remains unknown. We have assessed whether BMSCs-derived hepatocyte-like cells can function like liver cells and be infected by HBV. A new and efficient way to direct the differentiation of BMSCs into functional hepatocytes was developed. BMSCs obtained from hepatitis B patients were induced to differentiate into hepatocytes through exposure to HGF, FGF-4, and EGF. After 6 days of exposure, BMSCs-derived hepatocyte-like cells that expressed a subset of hepatic genes and showed hepatic functions were obtained. HBV was used to infect the differentiated cells, and subsequently these cells were assayed for the presence of HBeAg, HBsAg, and HBV DNA. BMSCs proved resistant to HBV infection, both in vitro and during differentiation into hepatocytes in vitro. This demonstrates that BMSCs are resistant to HBV infection. BMSCs are viable for transplantation and should facilitate further research exploring the in vivo HBV-resistance of the hepatocytes derived from BMSCs after transplantation, a characteristic that could form the basis for hepatocyte transplantation.

Topics: Adult; Cell Differentiation; DNA, Viral; Epidermal Growth Factor; Fibroblast Growth Factor 4; Hepatitis B; Hepatitis B e Antigens; Hepatitis B Surface Antigens; Hepatitis B virus; Hepatocyte Growth Factor; Hepatocytes; Humans; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells

Human hepatocyte growth factor (hHGF) has been purified approximately 209,000-fold with 18% yield from plasma of a patient with fulminant hepatic failure. The purification involves heat treatment of plasma, ammonium sulfate precipitation, and chromatography on Affi-Gel Blue, heparin-Sepharose, and hydroxylapatite. Purified hHGF shows several bands with molecular weights between 76,000 and 92,000. Each band shows growth-stimulating activity on cultured hepatocytes which is proportional to the intensity of the band. After reduction of the sample with 2-mercaptoethanol, SDS-PAGE yields two chains with molecular weights of 31,500-34,500 and 54,000-65,000. The effect of hHGF on DNA synthesis by hepatocytes is half-maximal at 3.5 ng/ml. hHGF stimulates proliferation of cultured hepatocytes more effectively than human epidermal growth factor (hEGF) or insulin, and the effect of hHGF is additive or synergistic with the maximal effects of hEGF and insulin. These results suggest that hHGF is a new growth factor which is different from hEGF.

Topics: Cell Division; Cells, Cultured; Chromatography; Epidermal Growth Factor; Hepatitis B; Humans; Insulin; Interleukin-6; Liver; Liver Regeneration; Molecular Weight; Proteins