Changing expression of E- and P-cadherin during rat tongue carcinogenesis induced by 4-nitroquinoline 1-oxide.

Background: Oral squamous cell carcinoma (SCC) develops from pre-malignant lesions, but the role of cell adhesion molecules such as E-cadherin (E-CD) and P-cadherin (P-CD) in the pre-malignant stage has not been elucidated.

Methods: The expression of E-CD and P-CD was examined immunohistochemically and biochemically in a 4-nitroquinoline 1-oxide (4NQO)-induced rat model of carcinogenesis.

Results: The expression of E-CD in the pre-malignant stage was the same as that in the normal epithelium.

Correlation of P-cadherin and beta-catenin expression and phosphorylation with carcinogenesis in rat tongue cancer induced with 4-nitroquinoline 1-oxide.

Using biochemical and immunohistochemical techniques, we have investigated P-cadherin, beta-catenin, c-src and c-met protein expression, and phosphorylation of beta-catenin in a rat model of tongue cancer induced with 4-nitroquinoline 1-oxide. Six-week-old male Sprague-Dawley rats were given either normal drinking water (controls) or 50 ppm 4NQO solution as drinking water for 16 and 20 weeks. This treatment produced dysplasia and well-differentiated squamous cell cancer in rat tongues after 16 and 20 weeks, respectively.