MONENSIN AND FORSKOLIN INHIBIT THE TRANSCRIPTION RATE OF SUCRASE-ISOMALTASE BUT NOT THE STABILITY OF ITS MESSENGER-RNA IN CACO-2 CELLS

Treatment of Caco-2 cells with forskolin (25 muM) or monensin (I muM) has previously been shown to cause a marked decrease in the level of s ucrase-isomaltase (SI) mRNA, without any effect on the expression of d ipeptidylpeptidase IV (DPP-IV). In the present work, we report that th ere is no significant difference in the stability of SI mRNA between c ontrol and treated cells. On the other hand, we demonstrate a decrease in the transcription rate of SI mRNA which is sufficient to account f or the decrease in the steady-state level of SI mRNA both in forskolin - and monensin-treated Caco-2 cells.