The Efficiency of FK 506 in In Vitro Bone Formation by Human Bone Marrow Cells

Human marrow cells were collected from ilium of a 65 year-old male patient with lumbar spondylosis undergoing surgery, and cultured in T 75 flasks with standard MEM medium containing 15% bovine fetal serum. After 2 weeks in primary culture, marrow stromal cells were reseeded in 6 well plates and subcultured in the standard medium supplemented with 10nM dexamethasone (Dex) or/and 10 ng/ml FK 506. After 2 weeks of subculture, the culture tissues were prepared for biochemical study. High levels of ALP, and calcium were detected in Dex-treated cultures of human bone marrow cells. Values in the FK506+Dex group were significantly higher than in the Dex or FK506 groups. At 10 ng/ml, FK506 increased osteoblastic activity or ossification markers, and it also promoted ossification induced by Dex. FK506 alone showed no significant increase of these ossification markers in the absence of Dex. It is therefore possible that use of FK-506 as a bone repair-stimulating factor both in vitro and in vivo may promote more stable bone regeneration.