Research for jaw bone destruaction mechanisms accompanied with oral cancer proliferation

2002 Fiscal Year Final Research Report Summary

• Project/Area Number: 13671976
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 病態科学系歯学(含放射線系歯学)
• Research Institution: Ohu University
• Principal Investigator: ITO Hiroshi Ohu University, Faculty of Dentistry, Sub-professor, 歯学部, 助教授 (20184682)
• Co-Investigator(Kenkyū-buntansha): SUGIURA Junko Ohu University, Faculty of Dentistry, Lecturer, 歯学部, 講師 (80316471)
• Project Period (FY): 2001 – 2002
• Keywords: oral cancer / jaw bone / bone destruction / 4NQO / osteoclast

Research Abstract

We firstly performed a preliminary experiment, in which rat oral carcinomas were evoked through 4-nitoroquinoline 1 oxide (4NQO) in drinking water. Oral carcinomas with jaw bone invasion occurred in 60% rats which were administrated 4NQO. With this result, jaw invading oral carcinogenesis method through 4NQO as drinking water was established. The method contains 8-week administration of 20ppm 4NQO in drinking water to 7-week-old male F344 rats and a duration period for twenty-four weeks. Using this method, rat oral carcinomas destroying jaw bones were evoked. From these carcinomas, we tried to get oral carcinoma cell lines. Resected palatal carcinomas were cultured. Four or five month's cultivation brought two epithelial cell groups in vitro. Forming solid cellular mass, one of the cell groups showed an proliferation pattern similar to that of HeLa cells. In addition, using the ***ked cancer tissue and normal oral mucosal tissue, we investigated each localization pattern of a water channel protein, aquaporin-3, which functions as water-selective channels residing in the plasma membranes of water transporting cells. Through immunohistochemistry, in normal oral squamous epithelium, aquaporin-3 localization was found in cells of basal layer and prickle cell layer. In squamous cell carcinoma nests, by contrast, no localization of aquaporin-3 was observed in outermost layer of these nests. This finding was published in 44th annual meeting of Japanese Association of Oral Biology, October, 2002. We intend to establish cancer cell lines form cultivated cell groups, then, these cancer cells will be co-cultured with macrophages of spleen to clarify the relation ship between osteoclastic bone resorption and oral cancer proliferation.