Influence of sodium butyrate on HeLa cell morphology and proliferation.

The effect of one-week exposure to sodium butyrate on HeLa S3 cell cultures was studied with special regard to influence on prekeratin synthesis, by comparison to cultures similarly treated with the known proliferation inhibitor hydroxyurea, and not treated. Like hydroxyurea, sodium butyrate inhibited cell proliferation to a considerable degree, but accounted additionally for an increase in membrane-bound alkaline phosphatase activity, cellular prekeratin synthesis, tonofilament number, and filament bundle formation. These phenomena unequivocally indicate that sodium butyrate acted as a specific stimulator of Hela (epithelial) cell differentiation. Similar differentiation phenomena can be observed during early spontaneous keratinization of the stratified horny epithelium.