The evaluation of cell cycle proteins (cyclinD1, cyclinD3, P21, P27) and Ki-67 in giant cell lesions of bone

ABSTRACTThe Evaluation of Cell Cycle Proteins (CyclinD1, CyclinD3, P21, P27) and Ki-67 inGiant Cell Lesions of BoneThe cell cycle proteins have a crucial function in the transition between cyclephases. The alterations of these proteins have an important role in pathogenesis of severalhuman tumors. In our study; cell cycle proteins (cyclinD1, cyclinD3, p21, p27) and cellproliferation have been investigated in giant cell tumor of bone, aneurysmal bone cyst,giant cell reperative granuloma and giant cell tumor of tendon sheaths that has similarmorphology. Besides, the findings were compared within the all groups. Seventy cases(18 giant cell tumor of bone, 15 aneurysmal bone cyst, 21 giant cell reperativegranuloma, 16 giant cell tumor of tendon sheaths) have been retrieved from the files.CyclinD1, cyclinD3, p21, p27 as cell cycle proteins and Ki-67 as a proliferation markerwere applied by immunohistochemical method in all cases. CyclinD3, p21 and p27staining were similar for all cases. The numbers of positive staining with CyclinD1,cyclinD3, p21 and p27 in giant cells were found higher than mononuclear cellsindicating that these cycle proteins may have a key role in giant cell differentiation.CyclinD1 revealed negative staining in mononuclear cells of all giant cell tumor oftendon sheaths. We thought that these mononuclear cells in giant cell tumor of tendonsheaths may have different immunophenotypical features than mononuclear cells of theother bone lesions. Ki-67 staining was restricted in mononuclear cells of all cases whichwas a very characteristic feature. None of the cases showed positive Ki-67 staining ingiant cells. This finding supported that giant cells do not have any proliferative activity.In conclusion, mononuclear cells are responsible for the proliferative activity and the cellcycle proteins are associated with the giant cell formation. Because of the osteolyticactivity of giant cells, studies targeting these cycle proteins can provide non-surgicaltreatment opportunity.Key words: Bone, cell cycle proteins, giant cell, Ki-67.i