KIRITA Tadaaki Nara Medical University, Department of Oral and Maxillofacial Surgery, Associate Professor, 医学部, 助教授 (70201465)
KONISHI Noboru Nara Medical University, Second Department of Pathology, Professor, 医学部, 教授 (20145832)
|Budget Amount *help
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 2001: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2000: ¥1,300,000 (Direct Cost: ¥1,300,000)
The helix-loop-helix proteins, Id-1, Id-2, and Id-3, have been demonstrated to inhibit the activity of transcription factors and to play an important role in regulating cell growth and tissue-specific differentiation. To elucidate the involvement of Id in human oral squamous cell carcinoma (OSCC), we examined 83 OSCCs for the expression of Id proteins by immunohistochemistry, 24 OSCCs for the expression of Id-1 mRNA by in situ hybridization (ISH), and 6 of the tumors and on cell lysates of 5 OSCC cell lines by Western blot analysis. A higher and more frequent expression of Id-1 and Id-2 proteins (67.5 % and 55.4 %, respectively) was found in human OSCC compared to expression of Id-3 (47.0 %), that Id protein expression, particularly Id-1 expression, correlated with histological grade. Western blot analysis detected Id-1 protein in 4 of 6 tumor samples and in all cell lines. ISH demonstrated strong cytoplasmic localization of Id-1 mRNA in tumor samples at significantly higher levels. Increased Id expression might be closely related to the control of cell proliferation and differentiation in human OSCC. On the other hand, the expression of VEGF, E-cadherin, or Ki-67 showed no significant correlation, but the factors such as tumor morphology, a tumor thickness greater than 4mm, and Flt-4 expression were significantly associated with development of neck metastasis in patients with OSCC.