초록 ▼

B형 간염 바이러스 (Hepatitis B virus; HBV) 감염에서 기인되는 간암(HBV-associated HCC) 발생 과정에 HBx (HBV X protein)가 중요 역할을 하는것으로 널리 알려지고 있다. 본 과제에서는 암세포가 세포사멸 과정을 회피하여 지속적인 생존을 유지하게 하는데 핵심적인 역할을 한다고 알려진 PI3K/Akt 경로와 NF-kB 활성, PP2C의 활성, 그리고 FasL 발현에 HBx가 미치는 영향과 관련 분자생물학적 기전을 밝히고자 하였다.

- FasL promoter 분석하여 HBx-유

B형 간염 바이러스 (Hepatitis B virus; HBV) 감염에서 기인되는 간암(HBV-associated HCC) 발생 과정에 HBx (HBV X protein)가 중요 역할을 하는것으로 널리 알려지고 있다. 본 과제에서는 암세포가 세포사멸 과정을 회피하여 지속적인 생존을 유지하게 하는데 핵심적인 역할을 한다고 알려진 PI3K/Akt 경로와 NF-kB 활성, PP2C의 활성, 그리고 FasL 발현에 HBx가 미치는 영향과 관련 분자생물학적 기전을 밝히고자 하였다.

- FasL promoter 분석하여 HBx-유도 FasL 발현에 핵심인자가 Egr임을 밝힘
- 핵 수용체 Nur77이 FasL 발현을 도모함을 밝힘으로써 간암 면역회피 기전을 제시함.
- HBx가 Egr의 발현을 증가시킬 뿐만 아니라 단백질-단백질 상호작용과 보조활성자 CBP 모집을 통하여 Egr의 전사활성을 증가시킴을 밝힘.
- Chang X-31과 34의 세포생존에 있어서 NF-kB의 역할 제시.
- HBx가 PI3K 활성을 증가시킴을 보임으로써 세포생존 기전을 제시
- HBx와의 결합에 의한 PP2C의 탈인산화효소 활성 억제가 신호전달계에 미치는 영향 분석.
- Chang X-31과 34의 세포생존에 있어서 NF-kB의 역할 제시.
- 세포생존 유도 NF-kB downstream 유전자의 동정.
- HBx 단백질의 안정도에 ROS (활성산소종)이 미치는 영향을 밝힘.

o 학술지 발표:
1. Yun C, Um HR, Jin YH, Wang JH, Lee MO, Park S, Lee JH and Cho H, NF-B Activation by Hepatitis B Virus X (HBx) protein Shifts the Cellular Fate toward survival. Cancer Letters, 184(1):97-104 (2002) (SCI).
2. Lee MO, Kang HJ, Cho H, Shin EC, Park JH and Kim SJ. Hepatitis B virus x protein induced expression of the Nur77 gene. Biochem Biophys Res Commun, 288:1162-1168 (2001) (SCI).
3. Shin EC, Choi YH, Kim JS, Kim SJ, Park JH. Expression Patterns of Cytokines and Chemokines Genes in Human Hepatoma Cells. Yonsei Medical Journal,43(5) 657-664 (2002) (SCIE).
4. Yoo YG, Oh S-H, Park ES, Cho H, Lee N, Park H, Kim DK, Yu DY, Seong JK , Lee MO. Hepatitis B virus X protein Enhances Transcriptional Activity of Hypoxia-Inducible Factor-1 through Activation of Mitogen-Activated Protein Kinase Pathway. J Biol Chem, 278(40):39076-84 (2003) (SCI)
5. Wang JH, Yun C, Kim S, Lee JH, Yoon G, Lee MO, Cho H. Reactive oxygen species modulates the intracellular level of HBx viral oncoprotein. Biochem Biophys Res Commun. 310(1):32-39 (2003).
6. Kim JS, Kim YH, Lee JH, Kim K, Lee TH, KIM SJ, Park JH. Cisplatin-induced apoptosis in Hep 3B cells: mitochondria-dependent and -independent pathways. Biochem Pharmacol. in revision (2003) (SCI)
현재 6편의 논문을 국제 학술지에 발표하였거나 진행 중이며 곧 3편의 관련 논문을 투고할 예정임.
o 국제/국내 학회 발표:
Choi YH, et al. Transcriptional activity of peroxisome proliferator-activated receptor-gamma is inhibited by hepatitis B virus X protein. AACR Conference, Apoptosis and Cancer: Basic Mechanisms and Therapeutic Opportunities in the Post-Genomic Era, 2002. 2. 13-17 Waikoloa, Hawaii, USA 등 국제학술대회 13 편과 국내학술대회 11편 발표
o 연구인력양성:
대학원 박사과정 3명과 석사과정 10명이 본 연구에 참여하였으며 박사 1인과 석사 3인을 배출함.

Abstract ▼

Primary hepatocellular carcinoma (HCC) is one of the most frequent neoplasms encountered in the world. HCC has drown much attention particularly in Korea, since it is the second major cancer following stomach cancer and is associated with Hepatitis B virus (HBV) infection in most cases. Among the fo

Primary hepatocellular carcinoma (HCC) is one of the most frequent neoplasms encountered in the world. HCC has drown much attention particularly in Korea, since it is the second major cancer following stomach cancer and is associated with Hepatitis B virus (HBV) infection in most cases. Among the four proteins translated from the HBV genome, the X-gene product (HBx) is thought to be important in causing HCC. In the present study, we investigated the role of HBx in the modulation of a major cell survival and immune escape network that composed of PI3K/PTEN/Akt, NF-kB, PP2C, and FasL expression.

- Egr was identified as an important transactivator of FasL by FasL promoter analysis.
- Induction of Nur77 was observed following HBx expression in Chang X-34 and HBV-integrated cell lines established from HCC patients. Nur77 may contribute to leading HBx-induced Fas/FasL signaling pathway which eliminate invading Fas-expressing lymphocytes.
- HBx induced expression as well as transactivation of Egr by protein-protein interaction and recruiting co-activator CBP.
- The phosphorylation of Akt and STAT-3 were induced in HepG2 cells infected with HBx recombinant adenovirus, AV-HBx-GFP, suggesting a potential mechanism of HBx-induced cell survival.
- HBx which induces deregulated proliferation and transformation interacted with Ser/Thr protein phosphatase PP2C via N terminal catalytic domain, resulting in down regulation of PP2C phosphatase activity.
- Physiological role of NF-kappaB in cell survival of HBx-expressing cells either by treating sulfasalazine, a specific inhibitor of NF-kappaB, or by expressing IkappaBalpha super-repressor gene.
- Reactive oxygen species enhanced the level of HBx protein,, which was a novel aspect of HBx regulation.

o Publications:
1. Yun C, Um HR, Jin YH, Wang JH, Lee MO, Park S, Lee JH and Cho H, NF-B Activation by Hepatitis B Virus X (HBx) protein Shifts the Cellular Fate toward survival. Cancer Letters, 184(1):97-104 (2002) (SCI).
2. Lee MO, Kang HJ, Cho H, Shin EC, Park JH and Kim SJ. Hepatitis B virus x protein induced expression of the Nur77 gene. Biochem Biophys Res Commun, 288:1162-1168 (2001) (SCI).
3. Shin EC, Choi YH, Kim JS, Kim SJ, Park JH. Expression Patterns of Cytokines and Chemokines Genes in Human Hepatoma Cells. Yonsei Medical Journal,43(5) 657-664 (2002) (SCIE).
4. Yoo YG, Oh S-H, Park ES, Cho H, Lee N, Park H, Kim DK, Yu DY, Seong JK , Lee MO. Hepatitis B virus X protein Enhances Transcriptional Activity of Hypoxia-Inducible Factor-1 through Activation of Mitogen-Activated Protein Kinase Pathway. J Biol Chem, 278(40):39076-84 (2003) (SCI)
5. Wang JH, Yun C, Kim S, Lee JH, Yoon G, Lee MO, Cho H. Reactive oxygen species modulates the intracellular level of HBx viral oncoprotein. Biochem Biophys Res Commun. 310(1):32-39 (2003) (SCI).
6. Kim JS, Kim YH, Lee JH, Kim K, Lee TH, KIM SJ, Park JH. Cisplatin-induced apoptosis in Hep 3B cells: mitochondria-dependent and -independent pathways. Biochem Pharmacol. in revision (2003) (SCI)
o Presentations:
00 presentations for International Meetings and 00 for Domestic Meetings including Choi YH, et al. Transcriptional activity of peroxisome proliferator-activated receptor-gamma is inhibited by hepatitis B virus X protein. AACR Conference, Apoptosis and Cancer:Basic Mechanisms and Therapeutic Opportunities in the Post-Genomic Era, 2002. 2. 13-17 Waikoloa, Hawaii, USA
o Education:
One Ph. D and three Masters were graduated.

목차 Contents

• Ⅰ. 연구계획 요약문...3
• 1. 국문요약문 ...3
• Ⅱ. 연구결과 요약문...4
• 1. 국문요약문 ...4
• 2. 영문요약문 ...5
• Ⅲ. 연구내용...6
• 1. 서론 ...6
• 2. 연구방법 및 이론 ...14
• 3. 결과 및 고찰 ...18
• 4. 결론 ...57
• 5. 인용문헌 ...60