ESTABLISHMENT AND CHARACTERIZATION OF STROMAL CELL-LINES THAT SUPPORTDIFFERENTIATION OF MURINE HEMATOPOIETIC BLAST CELLS INTO OSTEOCLAST-LIKE CELLS

This study aimed to establish and characterize a new stromal cell line that supports the proliferation of hematopoietic blast cells and thei r differentiation into osteoclast-like cells. Cells isolated from the calvaria of neonatal Balb/c mice were subcultured every 2 to 4 days at 1.2 X 10(4) cells/cm(2). After 18 passages the cells had become immor talized and were designated as MCHT-1. MCHT-1 cells were found to supp ort the proliferation of hematopoietic blast cells and their different iation into osteoclast-like cells when these two cells were co-culture d in the presence of 1 alpha,25(OH)(2)D-3 and dexamethasone. However, because the MCHT-1 cells showed heterogeneity, cloning was performed a nd each clone was characterized. All the clones obtained supported the proliferation of hematopoietic blast cells and their differentiation into osteoclast-like cells irrespective of their obvious differences i n growth capacities and cytochemical characteristics. However, the tim e-course of the appearance of osteoclast-like cells differed among clo nes. The supportive effect of these clonal stromal cells on differenti ation of hematopoietic blast cells into osteoclast-like cells was comp letely dependent on the presence of 1 alpha,25(OH)(2)D-3 and dexametha sone. These clonal MCHT-1 cells are expected to be useful for precise analysis of the proliferation and differentiation of osteoclasts.