1/2. The reaction of giant cell tumors of bone to transplantation into athymic nude mice: including observations on osteoinduction in the host bed.Fresh biopsy specimens of three typical human giant cell tumors (GCT) were transplanted into athymic mice. The transplants were encapsulated in a host bed-derived fibrous connective tissue envelope. Multinucleated giant cells and mononucleated tumor cells survived chiefly on the vascularized surfaces of the inside of the envelope. fibroblasts proliferated and filled the interior of the transplants where vascularization was relatively insufficient. Since mitotic figures were absent in multinucleated cells, the question arises whether only the mononuclear stroma cells are neoplastic in nature. Multinucleated cells occasionally showed endocytosed pyknotic cells, and survived transplantation for as long as 35 days. When the original tumor contained islands of osteoid and bone cells, the transplants induced differentiation of mouse host bed connective tissue into normal new bone, including bone marrow.- - - - - - - - - - ranking = 1keywords = giant (Clic here for more details about this article) |
2/2. Characterization of a cell line derived from a human giant cell tumor that stimulates osteoclastic bone resorption.giant cell tumors of bone are common but unusual tumors that are comprised of multiple cell types. Most attention has been focused on the giant cells, which resemble osteoclasts morphologically and functionally. This study examines the properties of a cell line derived from mononuclear cells from one of these tumors, since it appears likely that these cells may be able to influence the activities of cells with the osteoclast phenotype. This cell line, C433, has the following characteristics: (1) it represents undifferentiated cells, not recognized by any known antigenic markers for leukocytes; (2) it contains tartrate-resistant acid phosphatase; (3) it responds to the osteotropic factors 1,25 dihydroxyvitamin D3, insulin-like growth factor i and II, but not to parathyroid hormone; (4) it forms sarcomas in nude mice; and (5) it produces an activity that stimulates isolated avian and rat osteoclasts to resorb bone. This cell line may be useful in examining interactions between osteoclasts and accessory cells involved in bone resorption.- - - - - - - - - - ranking = 0.83333333333333keywords = giant (Clic here for more details about this article) |