Localization of fodrin in oral precancerous lesion and squamous cell carcinoma

The distribution of fodrin in oral precancerous lesions and squamous cell carcinoma was examined by immunoperoxidase staining. In normal mucous epithelium and leukoplakia, fodrin was localized mainly along the plasma membrane of the granular, prickle and basal cells of the mucous epithelium. Diffused distribution was also observed in the cytoplasm of basal cells. In contrast, staining of fodrin was not clear in well-differentiated squamous cell carcinoma. It decreased markedly at the plasma membrane of the basal-like cells and slightly at the plasma membrane of prickle-like and glanular cells. However, diffused distribution of fodrin appeared in the cytoplasm of prickle-like and granular-like cells. In the cytoplasm of the basal-like cells, labeling of fodrin increased when compared with the basal cells of normal epithelium. In undifferentiated squamous cell carcinoma, fodrin labeling was absent at the plasma membrane of peripheral cells in the cancer nests.The present findings indicate that the pattern of fodrin staining was consistently absent at the peripheral edge of the proliferation area in the early stages of carcinoma and the cancer nest of undifferentiated squamous cell carcinoma, and that fodrin is related to cell differentiation and proliferation.