Matrix metalloproteinase inhibition suppresses MMP-2 activity and activation of PANC-1 cells in vitro

Background. We have shown previously that the metalloproteinase inhibitor, BB-94, prolongs survival and attenuates MMP-2 activity in a murine model of pancreatic cancer. The purpose of this study was to determine the effect o f BB-94 on the activity and activation of MMP-2 by PANC-1 cells in vitro. Materials and methods. The poorly differentiated pancreatic cancer cell lin e PANC-1 was stimulated in vitro with the phorbol ester PMA (20 nM) and gro wn in the presence of increasing doses of BB-94 (0, 40, 200, and 400 ng/ml) for 24 h. Activation of MMP-2 was determined by gel zymography. In a separ ate experiment detailing the effects of BB-94 on MMP-2 activity, PANG cells were stimulated for 24 h with PMA and run out on four separate zymograms, each incubated in the previously noted concentrations of BB-94. Using densi tometry, band intensity on all gels was determined and compared for each co ncentration of BB-94. The Matrigel assay was used to determine BB-94's effe ct on the invasive potential of PANG cells at the previously studied concen trations. The presence of MT-MMP (a putative component of MMP-2 activation) was confirmed using Western blot in each group. Results. BB-94 inhibited the conversion of latent to active MMP-2 in a dose -dependent fashion. BB-94 also inhibited the activity of MMP-2 when run out on gel zymograms incubated with increasing concentrations of BB-94, Decrea sed activity and activation of MMP-2 by BB-94 were manifested by a signific ant reduction in the invasive potential of PANG as determined by the Matrig el assay. MT-MMP was universally present in each study group. Conclusions. The previously described salutary effects of MMP blockade in m ice implanted with pancreatic cancer can be explained in vitro by a dose-de pendent diminution of MMP-2 activity and activation in PANC cells exposed t o BB-94, (C) 1999 Academic Press.