Adenovirus-mediated gene transfer of Ras(N17) inhibits specific CCK actions on pancreatic acinar cells

CCK stimulates pleiotrophic responses in pancreatic acinar cells; however, the intracellular signaling pathways involved are not well understood. To e valuate the role of the ras gene product in CCK actions, a strategy involvi ng in vitro adenoviral-mediated gene delivery of a dominant-negative mutant Ras (Ras(N17)) was utilized. Isolated acini were infected with various tit ers of either a control adenovirus or an adenoviral construct expressing Ra s(N17) for 24 h before being treated with CCK. Titer-dependent expression o f Ras(N17) in the acini was confirmed by Western blotting. Infection with c ontrol adenovirus [10(6)-10(9) plaque-forming units/mg acinar protein (mult iplicity of infection of similar to 1-1,000)] had no effect on CCK stimulat ion of acinar cell amylase release, extracellular-regulated kinase (ERK) or c-Jun kinase (JNK) kinases, or DNA synthesis. In contrast, infection with adenovirus bearing ras(N17) increased basal amylase release, inhibited CCK- mediated JNK activation, had no effect on CCK activation of ERK, and inhibi ted DNA synthesis. These data demonstrate important roles for Ras in specif ic actions of CCK on pancreatic acinar function.