موتانت هاي PreS2 ويروس هپاتيت B در بيماران مبتلا به سرطان كبد (HCC)

Hepatitis B Virus PreS2 Mutants in Patients with Hepatocellular Carcinoma

Background and objective: hepatocellular carcinoma is amongst the most common cancers in the world. Chronic infection with HBV is a major cause of it. The pathogenesis of the carcinogenesis is not fully understood. PreS2 defective HBV variants may emerge during chronic HBV infection. This might have a role in HCC pathogenesis. Materials and methods: we investigated HBV variant with PreS2 mutant in HCC patients. Serum sample of 10 HCC patients were subjected to Semi Nested PCR and HBV DNA direct sequencing. Subsequently, sequences were aligned and compared with Database. Resultʹs: The sequence analysis showed a point mutation in the start codon of PreS2. There were some deletions with a 3, 6 and 8 amino acid in PreS2 region. Conclusions: PreS2 mutant viruses lack the potent HLA-restricted B- and T-cell epitopes harboring in the PreS2 product. This variant could escape from immune system surveillance. This PreS2 mutant protein accumulate in endoplasmic reticulum(ER), resulting ER stress. Then ER stress not only can induce oxidative DNA damage and genomic instability but also can induce proliferation - related signal pathways in the hepatocytes. In this condition cells may progress to tumor formation.