We have succeeded in transplanting human
osteogenic sarcoma of the mandible into nude mice. As the transplanted
tumor shows features of calcified
chondrosarcoma, this
tumor is thought to be an excellent model for study of the process of dystrophic endochondral calcification. Using this model, we studied relations between the expression of types I, II, and X
collagen and chondrogenic differentiation of the transplanted
tumor.
Collagen distribution during the development and growth of the transplanted
tumor was investigated by immunofluorescence with specific
antibodies against type I, II or X
collagen.
Type X collagen was intensely stained in the mineralized region. Almost all
tumor cells in this region were hypertrophic.
Type II collagen was chiefly distributed in the unmineralized region where
tumor cells showed chondrocytic or hypertrophic feature. These results indicate that the type of
collagen changes from type II to type X in the hypertrophic region and the
type X collagen may be synthesized by hypertrophic
tumor cells.
Type I collagen was localized in the marginal region of the
tumor, though it disappeared in the mineralized region.