肝炎ウイルスの増殖と肝発がん

1996 Fiscal Year Annual Research Report

• Project/Area Number: 06280122
• Research Institution: Japanese Foundation For Cancer Research
• Principal Investigator: 小池 克郎 財団法人癌研究會, 癌研究所, 部長 (30085625)
• Co-Investigator(Kenkyū-buntansha): 小原 道法 (財)東京都臨床医学, 総合研究所, 室長 (10250218) ; 小俣 政男 東京大学, 医学部, 教授 (90125914) ; 岡本 宏明 自治医科大学, 講師 (30177092) ; 吉倉 廣 東京大学, 医学部, 教授 (60012754) ; 村上 清史 金沢大学, 癌研究所, 教授 (90019878)
• Keywords: B型肝炎ウイルス(HBV) / C型肝炎ウイルス(HCV) / 肝発がん / X遺伝子 / 癌抑制遺伝子p53 / HCV遺伝子型 / predisposition / 細胞内局在性

Research Abstract

本年度は、HBVでは、発がんに関係が深くなってきたX遺伝子の機能について、X遺伝子とがん抑制遺伝子p53の機能的拮抗現象の詳細、X蛋白質と転写因子との相互作用の詳細を中心に研究した。HCVでは、肝がんで良く見い出されるHCVの遺伝子型や増殖に関わる遺伝子を中心に追求し、発がんに関係の深い遺伝子を明らかにするべく研究を行った。その結果、ウイルスのX遺伝子とがん抑制遺伝子p53の機能的拮抗現象が明かにされ、かつ、細胞の基本的転写装置や調節因子の研究と結びついた。この機能的拮抗現象は、増殖関連がん遺伝子、例えばc-fosやc-mycなどの基本転写装置からの転写開始がp53により抑制され、X遺伝子の発現により活性化されることが明かにされてたことと一致した。さらに、X遺伝子の発現は、細胞内でのp53の核移行を阻害することが分かった。このp53の細胞内局在性の変化は、p53遺伝子に変異を伴わないが、発がんの新しいリスクファクターとして考慮すべきであると考えられる。C型肝炎ウイルス(HCV)の研究では、ウイルスの遺伝子型と病態の関係、さらに、増殖に関わる遺伝子を中心とした研究を多角的に行った。これまでに、HCVの遺伝子型分類の分子的基盤を確立し、かつ、肝病変の進展と1b型の相関性が高いことを示唆した。さらに、ヒトリンパ球培養系を用いてHCVの感染増殖性を観察することが出来るようになった。そこで、培養細胞由来のHCVについてチンパンジー感染実験を行った。上記のように、本研究は、二つの異なったウイルスの多段階肝発がんでの役割の共通点または相違点を見いだしながら解析し、慢性肝炎および肝発がんの発症予防に重要な示唆を与えるものとなった。

Research Products

• [Publications] Takada,S.,et al.: "Hepatitis B virus X gene expression is activated by X protein but repressed by p53 tumor suppressor gene product in the transient expression system" Virology. 216. 80-89 (1996)
• [Publications] Koike,K.,et al.: "Hepatitis B virus DNA integration frequently observed in the hepatocellular carcinoma DNA of hepatitis C virus-infected patients" Internatl.J.Oncol.8. 781-784 (1996)
• [Publications] Hara,T.,et al.: "Effects of fusogenic and DNA-binding amphiphilic compounds on the receptor-mediated gene transfer into hepatic cells by asialofetuin-labeled liposomes" Biochim.Biophys.Acta. 1278. 51-58 (1996)
• [Publications] Koike,K.,et al.: "HBV DNA integration and insertional mutagenesis" in "Hepatitis B virus : Molecular mechanisms in desease and novel strategies for therapy" Imperial College Press.London. (in press). (1996)
• [Publications] Urashima,T.,et al.: "ldentification of hepatitis B virus integration in hepatitis C virus-infected hepatocellular carcinoma tissues" J.Hepatology. (in press). (1997)
• [Publications] Naito,M.,et al.: "Simple method for efficient production of hepatitis B virus core antigen in Escherichia coli" Res.Virol.(in press). (1997)
• [Publications] Nakamichi,N.,et al.: "Structure and expression of integrated hepatitis B viruse genes in an HBs antigen producing human continuous cell line (huGK-14)" Cytotechnology. in press. (1997)
• [Publications] Murakami,S.,et al.: "Human hepatitis B virus X protein is a transcriptional regulator that interacts with TFIIB and RNA polymerase" in Recent progress in liver cancer and hepatitis. 202-203 (1996)
• [Publications] Lin,Y.,et al.: "Delineation of interaction sites of hepatitis B virus X protein and tumor suppressor p53" in Viral Hepatitis and Liver Diseases. (in press). (1997)
• [Publications] Lin,Y.,et al.: "Hepatitis B virus X protein is a transcriptional modulator that communicates with transcription factor TFIIB and the RNA polymerase subunit RPB5" J.Biol.Chem.(in press). (1997)
• [Publications] Ohno,H.,et al.: "Human hepatitis B virus enhancer 1 is responsive to human interleukin-6" J.Med.Virol.(in press). (1997)
• [Publications] Yotsuyanagi,H.,et al.: "Prolonged fecal excretion of hepatitis A virus in adult patients with hepatitis A as determined by polymerase chain reaction" Hepatology. 24. 10-13 (1996)
• [Publications] Moriya,K.,et al.: "In vivo inhibition of hepatitis B virus gene expression by antisense phosphorothioate oligonucleotides" Biochem.Biophys.Res.Comm.218. 217-223 (1996)
• [Publications] Koike,K.,et al.: "Sialadenitis resembling Sjogren's syndrome in hepatitis C virus envelope gene transgenic mice" Proc.Natl.Acad.Sci.USA. 94. 233-236 (1997)
• [Publications] Koike,K.,et al.: "Transgenic mouse model for hepatocellular carcinoma Viral Hepatitis and Liver Disease" (in press). (1997)
• [Publications] Tokita,H.,et al.: "Hepatitis C virus variants from Jakarta,lndonesia classifiable into novel genotypes in the second (2e and 2f),tenth (10a) and eleven (11a) genetic groups" J.Gen.Virol.77. 293-301 (1996)
• [Publications] Egawa,K.,et al.: "Hepatitis C virus antibody,viral RNA and genotypes in leprous patients in Japan" J.Hepatolo.24. 397-402 (1996)
• [Publications] Holland,P.V.,et al.: "Genotyping hepatitis C virus isolates from Spain,Brazil,China and Macau by a simplified PCR method" J.Clin.Microbiol.34. 2372-2378 (1996)
• [Publications] Lvov,D.K.,et al.: "Prevalence of hepatitis C virus and distribution of its genotypes in Northern Eurasia" Arch.Virol.41. 1613-1622 (1996)
• [Publications] Shimizu,Y.K.,et al.: "A Hyperimmune Serum against a Synthetic Peptide Corresponding to the Hypervariable Regionl of Hepatitis C Virus Can Prevent Viral Infection in Cell Cultures" Virology. 15. 409-412 (1996)
• [Publications] Nakajima,N.,et al.: "Characterization of Long Term Cultures of Hepatitis C Virus." J.Virol.70. 3325-3329 (1996)
• [Publications] Yoshikura,H.,et al.: "Replication of Hepatitis C Virus" J.of Viral Hepatitis. 3. 3-10 (1996)
• [Publications] Shimizu,Y.K.,et al.: "Hepatitis C Virus : Detection of Interacellular Virus Particles by Electron Microscopy" Hepatology. 23. 205-209 (1996)
• [Publications] Kashiwakuma,T.,et al.: "Detection of hepatitis C virus specific core protein in serum of patients by a sensitive fluorescence enzyme immunoassay (FEIA)" J.Immunological Methods. 190. 79-89 (1996)
• [Publications] Orito,E.,et al.: "Quantification of serum hepatitis C virus core protein level in patients chronically infected with different hepatitis C virus genotypes." GUT. (in press). (1997)
• [Publications] Barba,G.,et al.: "Hepatitis C Virus Core Protein shows an exclusively Cytoplasmic Localization and Associates to Cellular Lipid Storage Droplets" Proc.Natl.Acad.Sci.USA. (in press). (1997)
• [Publications] Kuzushita,N.,et al.: "Increased frequency of HLA DR13 in hepatitis C virus carriers with persistently normal ALT levels" J.Med.Virol.48. 1-7 (1996)
• [Publications] Yuki,N.,et al.: "Hepatitis C biochemical remission and viral replication in haemodialysis patients" J.Med.Virol.48. 242-246 (1996)
• [Publications] Yuki,N,et al.: "Quantitative analysis of antibody to hepatitis C virus envelope 2 glycoprotein in patients with chronic hepatitis C infection" Hepatology. 23. 947-952 (1996)
• [Publications] Hagiwara,H.,et al.: "Long-term biochemical and virological response to natural interferon a in patients with chronic hepatitis C" Dig.Dis.Sci.41. 1001-1007 (1996)
• [Publications] Kanto,T.,et al.: "Low expression of erythrocyte complement receptor type 1 in chronic hepatitis C patients" J.Med.Virol.50. 126-134 (1996)
• [Publications] Takano,S.,et al.: "Prospective assessment of donor bloc screening for antibody to hepatitis C virus by fisrt-and second-generation assays as a means of preventing posttransfusion hepatitis" Hepatology. 23. 708-712 (1996)
• [Publications] Tanaka,F.,et al.: "High incidence of ADH2*1/ALDH2*1 genes among Japanese alcohol dependents and patients with alcoholic liver disease" Hepatology. 23. 234-239 (1996)
• [Publications] Tagawa,M.,et al.: "Gene expression and active replication in the liver after injection of duck hepatitis B virus DNA into the peripheral vein of ducklings" J.Hepatol.24. 328-334 (1996)
• [Publications] Kanai,F.,et al.: "Gene therapy for a-fetoprotein-producing human hepatoma cells by adenovirus-mediated transfer of the herpes simplex virus thymidine kinase gene" Hepatology. 23. 1359-1368 (1996)
• [Publications] Niwa,Y.,et al.: "Quantitation of a-fetoprotein and albumin messenger. RNAs in human hepatocellular carcinoma" Hepatology. 23. 1384-1392 (1996)
• [Publications] Kato,N.,et al.: "Hepatitis C virus genotypes : Molecular basis and clinical significance" in Progress in Liver Diseases. 223-244 (1996)