Fibronectin increases XXXX activity through inhibition of PKA in the human gastric cancer cell line SGC-7901.

@entity268 @entity5 @entity3547 @entity19319 @entity1928
Fibronectin/integrin-mediated signaling plays a key role in the regulation of adhesion, migration and metastasis of @entity5 . Numerous studies have addressed the significance of the association between integrin and @entity3547 , but the exact mechanism is unclear. Results from laboratories, including ours, have demonstrated that PKA inhibits the activity and function of @entity3547 . This study was designed to investigate the relationships among the fibronectin/integrin-, @entity268 /PKA- and @entity3547 -mediated intracellular signal transduction pathways. Rho activity was detected by pull-down assay. @entity268 concentration was measured by radioimmunoassay. The distribution of the PKA catalytic subunit and the phosphorylation of @entity19319 ( @entity19319 ) were detected by fluorescence microscopy and Western blotting, respectively, to examine the activation of PKA. @entity268 -mediated gene expression activity was analyzed using a luciferase reporter gene assay. The results revealed that, in SGC-7901 cells, soluble fibronectin increased @entity3547 activity and blocked the inhibition of @entity3547 activity by @entity268 /PKA. The @entity268 level, which was increased by @entity1928 and pertussis toxin, was decreased by fibronectin. The nuclear location of the PKA catalytic unit, the phosphorylation of @entity19319 and @entity268 response element (CRE)-directed reporter gene expression induced by @entity1928 were blocked by fibronectin. However, fibronectin did not block @entity19319 phosphorylation or CRE-directed reporter gene expression induced by @entity268 . These data suggest that fibronectin/integrin induces @entity3547 activation through the inhibition of @entity268 /PKA signal transduction. The possible point of action of fibronectin/integrin is adenylate cyclase.
