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Matrix metalloproteinases (MMPs) play an active role in facilitating the invasion of cancer cells with excessive extracellular matrix (ECM) degradation. In the present study, we investigated the antiinvasive effects of isorhamnetin, a naturally occurring flavonoid, on MDA-MB-231 human breast carcinoma cells. The results indicated that isorhamnetin significantly inhibited the adhesion, migration, and invasion of the cells in vitro. Moreover, isorhamnetin suppressed the activity and expression of MMP-2 and MMP-9, which were determined by gelatin zymography, real-time PCR, and Western blot analysis, respectively. Besides, isorhamnetin had little effect on the secretion of urokinase plasminogen activator. Further elucidation of the mechanism revealed that isorhamnetin exerted an inhibitory effect on the phosphorylation of p38 and STAT3, although it had no effect on ERK1/2 and JNK. Taken together, these data demonstrated that isorhamnetin could significantly inhibit the invasion of MDA-MB-231 cells by downregulating the expression and activity of MMP-2 and MMP-9, which was potentially associated with the suppression of p38 MAPK and STAT3. Therefore, the findings provide new evidence for the anti-cancer activity of isorhamnetin. [ABSTRACT FROM PUBLISHER]

As a continuation of previous research, fifteen bifendate derivatives bearing 6,7-dihydro-dibenzo [c,e]azepine scaffold were synthesized and evaluated as P-gp-medicated multidrug resistance (MDR) reversal agents. Biological evaluation indicated that compounds 6k and 9c more potently reversed P-gp-mediated MDR than bifendate and verapamil (VRP) by blocking P-gp mediated drug efflux function and not by decreasing P-gp expression in K562/A02 MDR cells. Interestingly, wound-healing and chamber migration assay showed that 6k and 9c could significantly attenuate the migration of MDA-MB-231 cells. Notably, 6k and 9c could markedly suppress the invasive activity of MDA-MB-231 cells, thus displayed potential anti-metastasis activity. Preliminary mechanism studies indicated that the anti-metastasis activity of 6k and 9c was associated with their inhibitory effect on the activity and expression of MMP-2 and MMP-9. These results, together with the MDR reversal results indicated that compounds 6k and 9c might be promising leads for developing novel anti-cancer agents with P-gp and tumor metastasis inhibitory activities. [ABSTRACT FROM AUTHOR]