Cytokeratin expression in human fetal tongue and buccal mucosa

Expression of cytokeratins (CK), a subset of intermediate filament (IF) pro teins in epithelia, is developmentally regulated. CK expression may also ch ange after malignant transformation. Our earlier studies on CK expression i n human oral tumours and pie-cancerous lesions have shown specific changes in CK expression. We analysed CK expression in human tongue and buccal muco sa (BM) in fetuses in the embryonic age group of 16 to 27 weeks using bioch emical and immunohistochemical techniques to find out whether there is any similarity in CK expression in human oral squamous cell carcinomas (SCC) an d fetal oral tissues. CK 1, 8 and 18 were detected in a majority of samples using both techniques. Our earlier studies had shown aberrant expression o f CK 1 and 18 in many of the oral SCC and leukoplakias. Studies by immunohi stochemistry showed that these different CK antigens were expressed in diff erent cell layers. CK 1(2) were present in the stratified epithelial layers whereas CK 8 and 18 were restricted to glandular epithelium. Till 27 weeks of gestation, both tongue and BM expressed CK 1, 8 and 18 along with CK 6 and 16. Thus, fetal tissues showed some similarities in CK pattern with the ir respective SCC.