Association of viral load and HBx protein expression in the development of hepatocellular carcinoma among explanted/resected liver tissues of chronic HBV patients

Abstract

HCC is the 3rd deadliest type of liver cancer globally and it represents 90% of primary cases of liver cancer. It is highly lethal and is unique in its own way with the mortality rate and incidence rate nearly equal. The major factors that are involved in HCC progression and development are persistent viral infections by Hepatitis B and Hepatitis C viruses, extreme alcohol consumption, liver cirrhosis, long term tobacco smoking, contamination of food by Alfatoxin B1 and certain metabolic disorders. Persistent CHB infection is greatly associated with HCC and 54% of the HCC occurrences worldwide are connected to HBV infection thus making it a second most prevalent carcinogen globally after tobacco. HBx is a multifunctional protein, and is necessary for the occurrence and perpetuation of HBV infection in vitro and in vivo usually by mechanisms like cccDNA regulation, transcriptional activity, degrading the host factors with antiviral properties and inhibiting the activity of innate effector cells. The present study aims in giving an understanding of the correlation between viral load and HBx protein expression in the development of HCC among resected/explanted liver tissues of chronic HBV patients. Our study was designed to exhibit the HBx persistence in the infected hepatocytes even after long term vigorous HBV treatments that halt the viral replication and the decreases the viral load but HBx protein still express itself and is involved in HCC progression and this also and can play a key role in relapse of HCC after cessation of treatment. Total 27 samples were enrolled in the study and were obtained from Hepato Pancreato-Biliary Liver Transplant Unit of Sheikh Zayed Hospital Lahore. 20 of them 18 were HCC liver samples. Out of which 5 were HBV associated HCC liver samples. HBV DNA was extracted and then Quantification of HBV DNA was performed to give viral load. Some samples had detectable HBV DNA (20%) while most samples had undetectable HBV DNA (80%) in their liver tissues Immunohistochemistry (IHC) based qualitative expression analysis of HBx protein was carried out. For detection and visualization of immunostained liver tissues microscopy was performed. In our current study it was observed that Semi-quantitative analysis of HBx via IHC showed persistent HBx expression in liver tissues of all HBV-HCC patients, irrespective of the detectable or undetectable HBV-DNA in their liver tissues, with (40%) of the liver tissues having Low (01), while (40%) having Moderate (02) and (20%) having High (03) IHC scores. We correlated the HBV viral load and HBx protein expression and HBV viral load and HBx protein expression are found to be correlated statistically under this study. Concluded from this study is the clarity of the part of HBx in the occurrence and progression of HCC even with lifelong treatment that halts the viral replication but do not eradicate HBx from infected hepatocytes and due to this ability HBx is involve in HBV persistence. The expression of HBx protein explicitly was assessed and evaluated in upsetting/irritating the normal routes, leading towards the mechanisms that instigates a shift from hepatic recovery to hepatocarcinogenesis and it will help in providing a novel research plan of action for the future treatment of liver cancer