Enhanced expression of tonofilament bundles during hamster cheek pouch carcinogenesis is associated with tumour growth and the loss of high molecular weight keratins

The altered pattern in the expression of keratin proteins as a function of tumour progression was studied in the hamster cheek pouch and compared the changes with electron microscopic observations using DMBA as a carcinogen. In the case of hyperplasia and well developed tumours a conspicuous loss of 67 K and an increase in 46 K was observed compared to the controls. The increased expression of low molecular weight keratins during tumour growth is well supported by the enhanced expression of tonofilament bundles, electron microscopically. This study suggests a triangular relationship between the presence of low molecular weight keratins-enhanced expression of tonofilament bundles and the undifferentiated nature of the oral tumours.