Risedronate Effects on Bone Metastasis of Rat Mammary Tumor Cell Lines

When compared to MTA cells MTB-01 cells were susceptible to risedronateinduced apoptosis had decreased ability to bind to risedronate-treated bone and did not produce MMP-2 or MMP-9 proteases. MTA cells were less susceptible to risedronateinduced apoptosis and produced MMP-2. Additionally adhesion of MTA cells to bone matrix was not diminished by risedronate treatment. Our results suggest that the nonresponsive nature of the MTA cell line may be due to MMP-2 production (possibly allowing ongoing destruction of risedronate-treated bone) continued adhesion to risedronate-treated bone matrix and decreased susceptibility to risedronate-induced apoptosis.