A role for AP-1 in matrix metalloproteinase production and invadopodia formation of v-Crk-transformed cells.

Both MMP-2 and MMP-9 play critical roles in tumor invasion, but their productions are differentially controlled. While the promoter region of MMP-9 has the conserved proximal AP-1 binding site, that of the MMP-2 has a noncanonical AP-1 site. To assess the role of AP-1 function, we examined the effects of dominant-negative Fos (DeltaFos), BATF and siRNA against c-Jun on MMP production in v-Crk-transformed cells which have augmented production of MMP-2 and MMP-9. Suppression of AP-1 dependent transcription by conditional expression of dominant-negative Fos (DeltaFos) and BATF substantially inhibited not only MMP-9 production but also MMP-2 production. The ChIP analysis showed the direct association of AP-1 and MMP-2 promoter region. In addition, silencing of c-Jun expression by siRNA transfection suppressed MMP-2 and MMP-9 production and in vitro invasiveness. Furthermore, the invadopodia formation of v-Crk-transformed cells could be suppressed by BATF expression or c-Jun siRNA treatment. Taken together, AP-1 appears to play a critical role in the production of MMP-2 and MMP-9 and invadopodia formation of v-Crk-transformed cells.