Transfection with shBMP-2 affected ALP activity and Runx2 mRNA level of MC3T3-E1 cells re-seeded on osteoblast-ECM. A, shBMP-2 reduced BMP-2 protein level of MC3T3-E1 cells. B, shBMP-2 lowered ALP activity of MC3T3-E1 cells seeded on cell culture plates without ECM coating (no ECM) , but had little effect on MC3T3-E1 cells seeded on osteoblast-ECM coated plates (ECM). C, shBMP-2 reduced Runx2 mRNA level, but had little effect on the cells seeded on osteoblast-ECM. ** P <0.01, *P <0.05, between the indicated groups, n = 5 per group.