guanosine-diphosphate and manumycin

To search for the intracellular signaling pathway critical for the secretion of matrix metalloproteinases (MMP), we studied the effects of dominant negative Ras (S17N Ras) and dominant negative MEK1 (MEK1AA) expression in v-crk-transformed 3Y1. Expression of either S17N Ras or MEK1AA dramatically suppressed the augmented secretion of MMP-2 and MMP-9 in v-crk-transfected 3Y1. Similarly, a Ras farnesyltransferase inhibitor, manumycin A, and a MEK1 inhibitor, U0126, suppressed MMP secretion in a dose-dependent manner, whereas a PI3 kinase inhibitor, wortmannin, could not. In addition, the suppression of MMP secretion by S17N Ras showed good correlation with the inhibition of in vitro invasiveness of the cells. In contrast, expression of dominant negative C3G did not suppress MMP secretion, although it substantially blocked the c-Jun N-terminal kinase activation. Taken together, the Ras-MEK1 pathway, but not the C3G-JNK pathway, seems to play a key role in the activation of MMP secretion and, hence, the invasiveness of v-crk-transformed cells.

Topics: Androstadienes; Animals; Butadienes; Cell Line, Transformed; Collagen; Drug Combinations; Enzyme Activation; Enzyme Inhibitors; Fibroblasts; Guanine Nucleotide-Releasing Factor 2; Guanosine Diphosphate; Guanosine Triphosphate; Immunoblotting; Laminin; MAP Kinase Kinase 1; MAP Kinase Signaling System; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Matrix Metalloproteinase Inhibitors; Matrix Metalloproteinases; Mitogen-Activated Protein Kinase Kinases; Nitriles; Oncogene Protein v-crk; Polyenes; Polyunsaturated Alkamides; Protein Serine-Threonine Kinases; Proteoglycans; ras Proteins; Rats; Retroviridae Proteins, Oncogenic; Signal Transduction; src Homology Domains; Wortmannin