Expression of keratins in normal, immortalized and malignant oral epithelia in organotypic culture

Keratins have been extensively studied in tissues and cultured keratinocyte s but limited information is available on epithelia reconstructed in vitro. The aim of this study was to examine keratin expression in organotypic epi thelia with normal (NOK), immortalized (SVpgC2a) and malignant (SqCC/Y1) hu man buccal cells. Organotypic epithelia were derived from 10 days of cultur e at the air-liquid interface of collagen gels containing human oral fibrob lasts using a standardized serum-free medium. Sections were stained immunoh istochemically with selected mono-specific antibodies to a range of keratin s. Organotypic epithelia showed sharp differences in keratin expression and distribution. K4/K13, K1/K10, K6/K16 were variably expressed in NOK and Sq CC/Y1 but were not detected in SVpgC2a. K5 was expressed in all organotypic epithelia but K14 was absent in SVpgC2a. K7 and K8 showed variable express ion while K18 was expressed uniformly in all epithelia. K19 was expressed c onsistently in NOK and K20 was distributed heterogeneously in SVpgC2a. Over all, organotypic cultures of normal keratinocytes express many of the same keratins as buccal mucosa. Further, the loss of keratins in SVpgC2a and the ir retention in SqCC/Y1 have several features in common with the respective keratin profile of oral epithelial dysplasia and well-differentiated oral squamous cell carcinoma. Although qualitative and quantitative differences exist compared to keratin expression in vivo, these cell lines in organotyp ic culture may serve in studies of the multi-step progression of oral cance r. (C) 2001 Elsevier Science Ltd. All rights reserved.