Comparative Studies on Tumor Protein 53 Gene Polymorphism, Demographic Attributes and Associated Risk Factors Among Hepatocellular Carcinoma and Liver Cirrhosis Patients in Calabar, Nigeria

Abstract

Mutations in the TP53 gene had been attributed to the development of liver cancer. Hepatocellular carcinoma (HCC) and liver cirrhosis are liver diseases having high mortality rates in several populations. There is no information on the TP53 gene polymorphism among liver diseases patients in Calabar, Nigeria. This study investigated the genetic polymorphism of TP53 among HCC and liver cirrhosis in Calabar. This research was carried out in the University of Calabar Teaching Hospital, Calabar. Blood was collected from 35 clinically diagnosed hepatocellular carcinoma and 10 cirrhosis patients and 10 healthy controls. DNA was extracted from all blood samples. Polymerase Chain Reaction (PCR) was performed. The amplicon was digested using Hae III restriction enzyme and the genotypic and allelic frequencies were determined. In liver diseases patients, male was 68.9% (31), female (31.1%; 14), sex ratio (2.2: 0.5), mean age was 41.51 ± 2.13 years and odd ratio of 1.25. Marital status of patients were 33(73.3%), 10(22.2%), and 2(4.4%) for married, single, and widowed respectively. Ethnicity of patients were Yakurr, Efik, Boki, Ogoja, Annang, Ibibio and Igbo having 22.2%(10), 20%(9), 13.3%(6), 13.3%(6), 8.8% (4), 2.2%(1) and 2.2%(1) respectively. Approximately, 64.7% (30) of the chronic liver diseases were from the Central and Northern part of Cross River State. The risk factors were HCV infection, HBsAg+, alcoholism, smoking, consumption of groundnuts that may have been contaminated with aflatoxin and family history of the disease. PCR product yielded 254bp and digested PCR product showed homozygous TT mutation (27), heterozygous GT mutation (17) and homozygous GG wild type (1) in cases. The overall TP53 gene mutation frequency was 46.32% (44). The frequency of G allele, T allele, GG, GT and TT genotypes were 0.21, 0.79, 0.04, 0.33 and 0.62 respectively among cases, while GG (wild type) was only detected among controls in the study population. The genotypic and allelic frequencies conform to Hardy-Weinberg equilibrium meaning that the forces of evolution were not acting on the locus. There were significant differences in the genotypic proportions of the TP53 gene polymorphism among patients and controls. This study on the TP53 gene polymorphism will serve as baseline information on the molecular etiology of hepatocellular carcinoma and liver cirrhosis in Cross River State.