[The abnormal expression of pRb during DMBA-induced hamster buccal pouch carcinogenesis]

To study the expression and role of pRb in 7,12-dimethylbenzanthracene(DMBA) induced hamster buccal pouch carcinogenesis.

DMBA (0.5%) in acetone was applied to the right buccal pouch 3 times per week for up to 12 week. Paraffin-embedded sections were used for pRb immunohistochemical determination (ISAB technipue, polyclonal antibody c-15 for pRb). The density of staining was analysed by rank sum test.

The positive staining of pRb was strong in normal buccal epithelium, no alteration of pRb staining in 3 week (hyperplastic epithelium) and somewhat reduced between 6 and 9 week (dysplastic lesion), but it was marked reduced in 12 week (carcinoma). Statistical analysis found that changes of pRb were associated with stages of carcinogenesis.

These results indicate that abnomal expression of Rb gene product could be related to oral carcinogenesis and may serve as a biomarker for supervising oral malignancy.