Osteolysis effect by fibroblasts derived from malignant bone tumor / 中国矫形外科杂志

ABSTRACT

[Objective]To investigate whether fibroblasts from malignant bone tumor could support osteoclast differentiation and bone resorption.[Method]Fibroblasts isolated from 8 fresh tumor samples were cultured in vitro.At passage two,part of these fibroblasts were co-cultured with peripheral blood monocytes.M-CSF,OPG and neutralizing anti-TNF-? antibody was added to the culture respectively.A Transwells system was also applied to observe the secretion of solvable factors in fibroblasts.At day 1,day 14 and day 21,the cultures on coverslips and bone slices were stopped and examined for the formation of tartrate resistant acid phosphatase(TRAP)positive multmucleated cells(MNCs)and lacuna resorption pits respectively.The number of lacuna resorption pits on bone slices,which was a marker of OC activity,was compared between the groups.Another part of the fibroblasts were cultured alone,and RT-PCR was performed to investigate the expression of RANKL and TNF-? mRNA in the fibroblasts.[Result]TRAP positive MNCs and lacuna pits were observed in the co-culture group in the presence of M-CSF,but not in the absence of M-CSE.It was also the case in the Transwell group,even though the number of lacuna pits was resuced.OPG completely inhibited the formation of TRAP positive MNCs and lacuna pits,while anti-TNF-? had not inhibiting effect on this process.RT-PCR results showed that both RANKL and TNF-? mRNA were positive in all the fibroblast involved.[Conclusion]In the presence of M-CSF,fibroblasts from malignant bone tumor are capable of supporting osteoclast formation and activity through expression of RANKL.