CULTURING OF CELLS FROM GIANT-CELL TUMOR OF BONE ON NATURAL AND SYNTHETIC CALCIFIED SUBSTRATA - THE EFFECT OF LEUKEMIA INHIBITORY FACTOR AND VITAMIN-D3 ON THE RESORBING ACTIVITY OF OSTEOCLAST-LIKE CELLS

Osteoclastic cells from giant cell tumour of bone (GCT) of bone provid e a rich source for investigation of cellular mechanisms leading to fo rmation of multinucleated cells, the resorption process and involvemen t of hormones and cytokines in these events. In the present study we i nvestigated the effect of 1,25-dihydroxyvitamin D3 (VD3) and leukaemia inhibitory factor (LIF) on the resorbing potential of osteoclast of G CT origin using quantitative image-analysis of resorption lacunae in a n in vitro dentine model. While VD3 unsignificantly increased the numb er of resorption pits and implicated surface after 7 days of GCT cell culturing, the stimulative effect of LIF was statistically significant . In cultures supplemented with LIF (5000 U/ml) the number of lacunae and resorption surface increased by 38% and 55%, respectively, when co mpared with control cultures. We suggest that both osteotropic agents increased osteoclastic activity, as the number of multinucleated cells was similar in control and experimental cultures. Seeding of GCT cell s on biphasic calcium phosphate substratum revealed the relative inabi lity of osteoclastic cells to resorb this synthetic material.