Making a model of digestive tract infection and carcinogenisis of Epstein-Barr virus produced by epithelial cell line (GTC) derived from human gastric adenocarcinoma.

2005 Fiscal Year Final Research Report Summary

• Project/Area Number: 16591354
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Digestive surgery
• Research Institution: Teikyo University
• Principal Investigator: FUKUSHIMA Ryoji Teikyo University, School of Medicine, Department of Surgery, Professor, 医学部, 教授 (50228897)
• Co-Investigator(Kenkyū-buntansha): OKINAGA Kota Teikyo University, School of Medicine, Department of Surgery, Professor, 医学部, 教授 (00101098) ; TAJIMA Masako Teikyo University, School of Medicine, Department of Surgery, Assistant, 医学部, 助手 (20211360)
• Project Period (FY): 2004 – 2005
• Keywords: Epstein-Barr virus / carcinogenisis / EBER / LMP-1 / Balb / c mouse / EBV infection

Research Abstract

Epstein-Barr virus (EBV) has been implicated in the pathogenesis of some type of gastric adenocarcinoma. We established an epithelial cell line (GTC-4) derived form human gastric cancer tissue. The cell line have a capacity of producing EBV. We further cloned EBV producing cell line GTC-5 from GTC-4 cells and found that digestive tract of Balb/c mice can be infected by EBV produced by GTC-5 (GTC-5-EBV) and finally infected mice developed adenocarcinoma of the digestive tract.
Balb/c mice were gavaged with 0.2ml of 50% ethanol to produce gastric mucosal injury and than GTC-5-EBV were gavaged. Histoimmunostaining showed that EBV nuclear antigen NA-2 were positive in the gastric mucosa 24 hours after the gavage of EBV and disappeared in 21 days. NA-1 and LMP-1 (latent membrane protein 1) were also present in gastric mucosa 5 days after the gavage and disappeared 6 months later. EBER (EBV-encoded small RNA) were identified in the gastric mucosa by in situ hybridization 24 hours after the gavage and it lasted for 9 months. EBER positive adenocarcinoma were developed in the stomach 9 months after the gavage of EBV.
In the next experiment, Balb/c nude mice (6-7W and 10 month, n=10 each) were used to evaluate the carcinogenesis of GTC-5-EBV. GTC-5-EBV was injected weekly for 8 times. After 4 months, adenocarcinoma were found in the rectum of 100 % of elderly mice. In contrast, no cancer was found in the young mice during the observation period of 6 months.
Our model of EBV associated carcinogenisis of digestive tract seems useful in studying the etiology and treatment of EBV associated disorders.