RETINOIC ACID MODULATION OF MUCIN MESSENGER-RNA IN RAT TRACHEAL EXPLANTS - RESPONSE TO ACTINOMYCIN-D, CYCLOHEXIMIDE, SIGNAL-TRANSDUCTION EFFECTORS AND ANTISENSE OLIGODEOXYNUCLEOTIDE

Factors affecting the retinoic acid modulated expression of mucin mRNA in rat tracheal cultures were studied. Actinomycin D had no effect on mucin mRNA in cultures grown with retinoic acid (RA(+)). The usual precipitous drop in mucin mRNA in cultures lacking retinoic acid (RA(-)) was prevented by actinomycin D. Cycloheximide also had no effect on mucin mRNA in RA(+) cultures, but, like actinomycin D, it prevented the precipitous drop in mucin mRNA in RA(-) cultures. cAMP agonists had same marginal effects on the mucin mRNA, but none as dramatic as those noted by actinomycin D and cycloheximide in the RA(-) cultures. An antisense oligomer (18 bases) to rat mucin cDNA inhibited the mucin mRNA expression in RA(+) cultures.