CYTOCHALASIN B-INDUCED MULTI-NUCLEATION OF MURINE SARCOMA VIRUS-TRANSFORMED CELLS - INHIBITION BY SODIUM BUTYRATE

Normal rat kidney (NRK) cells underwent only one nuclear division in the presence of 1-3 μg/ml cytochalasin B (CB), an inhibitor of cytoplasmic cleavage. In contrast, NRK cells transformed by murine sarcoma virus (MSV-NRK cells) became multinucleated when treated with CB. Sodium butyrate (2 mM), which induces striking morphological changes in MSV-NRK cells, prevents CB-induced multinucleation in these cells. Dibutyryl cyclic adenosine monophosphate (db-cAMP) also restores limited nuclear division to CB-treated MSV-NRK cells, but 8-bromo-cAMP does not. CB was found to selectively inhibit DNA synthesis in MSV-NRK cells grown in medium supplemented with 2 mM butyrate, but not in control MSV-NRK cells. This inhibition of DNA synthesis could account for the limitation of nuclear division by sodium butyrate. © 1978.