Temporal alterations in cytokeratin expression during experimental oral mucosal carcinogenesis

Abstract

Precancerous lesions and squamous cell carcinomas (SCCs) were induced in the oral mucosa of outbred male Sprague-Dawley rats by repeated application of the carcinogen 4-nitroquinoline-1-oxide. Temporal alterations in the pattern of cytokeratins expressed by epithelial cells in these developing neoplasms were investigated by means of one- and two-dimensional polyacrylamide gel electrophoresis and by probing electrophoretic blots of these gels with anticytokeratin antibodies. Progressive diminution in the expression of a 58.3 kDa cytokeratin was detected in moderately dysplastic epithelium and subsequent lesions, as was reduced expression of a 53.5 kDa cytokeratin after a stage of severe dysplasia had been induced. Analysis of two-dimensional electrophoretograms indicated an alkaline shift of acidic variants of a 49.0 kDa cytokeratin in moderately dysplastic epithelium; this shift was more pronounced in the induced, severely dysplastic epithelium and SCCs. The latter finding of an alkaline shift in cytokeratins of dysplastic epithelial cells has not been previously reported in preneoplastic lesions.

Downregulation of Keratin 76 Expression during Oral Carcinogenesis of Human, Hamster and Mouse

“…However, in-vitro data may not fully reflect the in-vivo condition [33]. Interestingly, alterations of keratin expression pattern marks the common signature in human oral cancers and experimental oral tumors developed in animal models [34], [35]. Hence, we selected in-vivo model systems: the hamster model to demonstrate K76 downregulation during sequential progression of oral cancer, and the KO mice model to evaluate the effect of KRT76 loss.…”

Primary squamous cell carcinoma of the thyroid gland: an entity with aggressive clinical behaviour and distinctive cytokeratin expression profiles

“…Each epithelium expresses between two and 10 cytokeratins in a characteristic, site‐specific manner. The expression profiles of cytokeratins has been shown to identify the different types of carcinomas 2–5 . Also, the expression of oncoproteins, like p53 and p21, may play a role in the pathogenesis and prognosis of carcinomas 6…”

Cytokeratin expression in oral submucous fibrosis – an immunohistochemical study

“…They concluded that this change seems to be associated with the process of carcinogenesis. Down regulation of 58.3 kDa keratins in severely dysplastic, 4NQO treated rat palatal mucosa has been shown by Nicholas et al (26) Furthermore, they have shown loss of these two keratins – CK5 and 14 in SCC of rat palatal mucosa. Down regulation of basic CK pair of 5 and 14 has also been shown by Morgan et al (6) in poorly differentiated SCC of oral mucosa.…”