Alpha-fetoprotein mRNA: variation of half-life in rat hepatoma cell lines and destabilization by sodium butyrate.

The half-life of alpha-fetoprotein (AFP) mRNA was determined in two rat hepatoma cell lines. In the 7777 cell line, AFP mRNA half-life is 30-35 h, consistent with earlier observations (Innis and Miller, 1979). However, the half-life in McA-RH8994 cells is only 14-16 h. Dexamethasone does not affect AFP mRNA half-life in either cell line, indicating that glucocorticoid-mediated alterations in AFP mRNA levels in these cells is at the transcriptional level. The naturally-occurring fatty acid sodium butyrate did, however, cause significantly more rapid degradation of AFP mRNA in McA-RH8994 cells, decreasing the half-life from 14-16 h to only 5-6 h. The ability of sodium butyrate to block glucocorticoid action on AFP gene expression in this cell line is therefore due to both transcriptional and post-transcriptional effects.