BMP7 (Bone morphogenetic protein 7), which belongs to the TGF-β superfamily, is a signaling molecule with the ability to promote bone formation. BMP7 has also been implicated in various types of cancer, including breast cancer. It has been reported that BMP7 treatment induced cell growth promotion of MDA-MB-231 breast cancer line. To test the effect of BMP7 on cell proliferation, MDA-MB-231 cells were seeded into triplicate wells of 96-well plates at a density of 2,000 cells/well and allowed to attach overnight, then the medium was replaced with serum-free standard DMEM prior to the addition of various concentrations of BMP7. After incubated for 72h, cells were observed by inverted microscope and cell proliferation was measured by Cell Counting Kit-8 (CCK-8). Briefly, 10µL of CCK-8 solution was added to each well of the plate, then the absorbance at 450nm was measured using a microplate reader after incubating the plate for 1-4 hours at 37°C.

The dose-effect curve of BMP7 was shown in Figure 2. It was obvious that BMP7 significantly promoted cell proliferation of MDA-MB-231 cells. The ED50 for this effect is typically 3.483 to 9.017 ng/mL.