Modification of cell growth-dependent gene transcript levels by sodium butyrate in serum stimulated fibroblasts

We have analyzed the effect of sodium butyrate, under conditions which block the transition from G0 to S phase, on the steady-state levels of several cell growth-dependent mRNAs in ts13 cells, a G1-specific temperature sensitive mutant of the BHK cell line. The RNAs studied were: beta-actin, vimentin, ATP/ADP translocase, histone H3 and p1B6, a cell growth-dependent sequence selected from a ts13-derived cDNA library. We found that induction of p1B6 RNA by serum in the presence of butyrate is greater than in its absence. The levels of histone and ATP/ADP translocase transcripts are lower when induced in the presence of butyrate, while beta-actin and vimentin RNA levels are little modified by the drug. Mitoguazone and incubation at the non-permissive temperature which, also, arrest cells at the pre-replicative stage, and hydroxyurea and cytosine arabinoside, which block them at the early S phase, have different effects on the levels of these transcripts.