Effect of 5-azacytidine on rat liver alpha-fetoprotein gene expression.

Neonatal rats given 5-azacytidine intraperitoneally (30 micrograms/animal/day) on days 1-5 postpartum had 55% lower serum alpha-fetoprotein levels on day 6 compared to saline injected controls. On day 14, alpha-fetoprotein levels were 4-fold lower in 5-azacytidine treated animals. Cytosol alpha-fetoprotein was proportionately reduced. There were no significant changes in liver to body weight ratio, total serum protein, and both serum and cytosol albumin levels. The molecular basis for decreased serum alpha-fetoprotein levels was found to be a reduced concentration of alpha-fetoprotein mRNA in the livers of 5-azacytidine injected animals. These results are discussed with respect to the effects of 5-azacytidine on DNA methylation and cell differentiation.