REGULATION OF CCK MESSENGER-RNA IN THE HUMAN NEUROEPITHELIOMA CELL-LINE SK-N-MCIXC IN RESPONSE TO 2ND MESSENGER ACTIVATORS

Regulation of cholecystokinin (CCK) expression was studied in the huma n neuroepithelioma cell line SK-N-MCIXC. The cells were treated with t he phosphodiesterase inhibitor isobutyl-methylxanthine and the tumor p romoting phorbol ester, phorbol-12-myristate 13-acetate; activators of the cyclic AMP (cAMP) and protein kinase C (PKC) second messenger pat hways, respectively. Levels of CCK mRNA were determined after 6, 12 an d 24 hour drug treatments, with Northern blot analysis using human CCK cDNA hybridization probes. Activation of both cAMP and PKC second mes senger pathways increased CCK mRNA levels in SK-N-MCIXC cells. These r esults indicate that the levels of CCK mRNA in SK-N-MCIXC cells are re gulated by cAMP and PKC dependent mechanisms.