Type I Saikosaponins A and D Inhibit Osteoclastogenesis in Bone Marrow-Derived Macrophages and Osteolytic Activity of Metastatic Breast Cancer Cells

Figure 5

Effects of saikosaponins A and D on cell viability, invasion, and PTHrP mRNA expression in MDA-MB-231 metastatic human breast cancer cells. (a) MDA-MB-231 cells were treated with saikosaponin A, saikosaponin D, and/or TGF-β (10 ng/mL) for 24 h. Cell viability was determined by MTT assay. (b) Cell invasion assay was performed using a transwell chamber containing a polycarbonate membrane filter (6.5 mm diameter and 8 μm pore size), coated with 0.1% (w/v) gelatin and Matrigel, as described in Materials and Methods. MDA-MB-231 cell suspensions with the indicated concentrations of saikosaponin A or D were added into the coated insert and the lower chamber was filled with 600 μL of medium containing 1% FBS, saikosaponin A or D, and TGF-β (10 ng/mL). Transwell plates were incubated for 24 h. After hematoxylin staining, the membranes with invaded cells were mounted on slides. (c) PTHrP mRNA expression was determined by quantitative real-time RT-PCR in MDA-MB-231 cells treated with TGF-β (10 ng/mL) and saikosaponin A or D at indicated concentrations for 24 h. GAPDH was used for normalization of mRNA analysis. The gene expression levels are indicated as fold changes. Data are expressed as mean ± SE. ^# and ^## versus untreated cells and ^* and ^** versus TGF-β-treated cells.

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