Sanae Hayashi1, Anis Khan1, Brenna C Simons2, Chriss Homan2, Takeshi Matsui3, Kenji Ogawa4, Keigo Kawashima1, Shuko Murakami1, Satoru Takahashi5, Masanori Isogawa1, Kazuho Ikeo6, Masashi Mizokami7, Brian J McMahon2, Yasuhito Tanaka1. 1. Department of Virology and Liver Unit, Nagoya City University Graduate School of Medical Science, Nagoya, Japan. 2. Liver Disease and Hepatitis Program, Alaska Native Tribal Health Consortium, Anchorage, AK, USA. 3. Center for Gastroenterology, Teine Keijinkai Hospital, Sapporo, Japan. 4. Chemical Genetics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, Japan. 5. Department of Experimental Pathology and Tumor Biology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan. 6. Center for Information Biology, National Institute of Genetics, Mishima, Japan. 7. The Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa, Chiba, Japan.
Abstract
Hepatitis B virus (HBV) genotype F1b infection is strongly associated with hepatocellular carcinoma (HCC) in young Alaskan Native (AN) people. However, the mechanisms by which genotype F1b causes HCC are unclear. Here, we analyzed the clinical and virological significance of genotype F1b in long-term serial samples from 20 HCC patients with HBV infection. Complete sequence analyses revealed that all isolates were genotype F1b. In the HCC patients, T1938C and A2051C mutations in the core region had accumulated significantly with A1762T/G1764A mutations in the basal core promoter (BCP) region and G1896A mutation in the precore (PC) region. Several HBV clones containing the core mutations were examined for their replication efficiency and core stability in vitro. Clones containing the A2051C mutation replicated more efficiently than the wild type in association with enhanced stability of core protein dimerization. In chimeric mice with human hepatocytes carrying BCP/PC/2051 mutant but not with wild-type virus, liver fibrosis was induced in association with high levels of serum HBV DNA and hepatitis B surface antigen. Interestingly, microarray analysis and validation study showed that five genes associated with cell proliferation or carcinogenesis, v-myc avian myelocytomatosis viral oncogene homolog, Grb2-associated binding protein 2, bradykinin receptor B2, follistatin, and mitogen-activated protein kinase kinase kinase 8, were significantly up-regulated in human hepatocytes infected with genotype F1b, particularly the BCP/PC/2051 mutant, compared with other genotypes. Conclusion: We have identified an association between Alaska-specific core mutations and HCC development in AN people infected with genotype F1b; accumulation of these core mutations during the course of chronic infection with genotype F1b would contribute to HCC development in AN people earlier in life.
Hepatitis B virus (HBV) genotype F1b infection is strongly associated with hepatocellular carcinoma (HCC) in young Alaskan Native (AN) people. However, the mechanisms by which genotype F1b causes HCC are unclear. Here, we analyzed the clinical and virological significance of genotype F1b in long-term serial samples from 20 HCC patients with HBV infection. Complete sequence analyses revealed that all isolates were genotype F1b. In the HCC patients, T1938C and A2051C mutations in the core region had accumulated significantly with A1762T/G1764A mutations in the basal core promoter (BCP) region and G1896A mutation in the precore (PC) region. Several HBV clones containing the core mutations were examined for their replication efficiency and core stability in vitro. Clones containing the A2051C mutation replicated more efficiently than the wild type in association with enhanced stability of core protein dimerization. In chimeric mice with human hepatocytes carrying BCP/PC/2051 mutant but not with wild-type virus, liver fibrosis was induced in association with high levels of serum HBV DNA and hepatitis B surface antigen. Interestingly, microarray analysis and validation study showed that five genes associated with cell proliferation or carcinogenesis, v-myc avian myelocytomatosis viral oncogene homolog, Grb2-associated binding protein 2, bradykinin receptor B2, follistatin, and mitogen-activated protein kinase kinase kinase 8, were significantly up-regulated in human hepatocytes infected with genotype F1b, particularly the BCP/PC/2051 mutant, compared with other genotypes. Conclusion: We have identified an association between Alaska-specific core mutations and HCC development in AN peopleinfected with genotype F1b; accumulation of these core mutations during the course of chronic infection with genotype F1b would contribute to HCC development in AN people earlier in life.
Authors: Chimaobi M Anugwom; Manon Allaire; Sheikh Mohammad Fazle Akbar; Amir Sultan; Steven Bollipo; Angelo Z Mattos; Jose D Debes Journal: Hepatoma Res Date: 2021-03-26