Using caffeoyl pyrrolidine derivative LY52, a potential inhibitor of matrix metalloproteinase-2, to suppress tumor invasion and metastasis.

LY52 is a caffeoyl pyrrolidine derivative designed to fit the S'1 active pocket of gelatinases that act in tumor invasion and metastasis. Herein, we examined the effects of LY52 on expression of matrix metalloproteinase (MMP)-2 expression in human breast cancer MDA-MB-231 cells and on in vitro invasion and in vivo metastasis. LY52 significantly blocked MMP-2 activity as evidenced by a decrease in the degradation of succinylated gelatin. Gelatin zymography analysis showed that LY52 (0.1-200 microg/ml) inhibited expression of active MMP-2 in concanavalin A-stimulated MDA-MB-231 cells. Inhibition of MMP-2 expression was also observed in tissue of tumor xenografts in mice that were orally administered LY52 (25 or 100 mg/kg). Furthermore, LY52 displayed an inhibitory effect on in vitro invasion of MDA-MB-231 cells and pulmonary metastasis of B16F10 murine melanoma cells in mice without significant toxic effects. These results suggest that LY52 is a potential MMP-2 inhibitor that may effectively suppress tumor invasion and metastasis.