[Expression of the p53 protein in human osteosarcoma]

The expression of the p53 tumor suppressor gene protein was analyzed in 35 resected osteosarcomas, 5 resected osteochondromas, and in 2 human osteosarcoma cell lines by immunohistochemistry and flow cytometry. An abnormality in the expression of the p53 protein was found in 10(29%) of the 35 osteosarcomas. An overexpression of the p53 protein showed no correlation with the clinicopathological features, but the p53 protein staining pattern showed a tendency to be correlated with aggressive growth and the metastatic potential. Diffusely-stained tumors had a worse prognosis than those focally-stained. The relationship between the expression of p53 protein and the cell cycle was examined by flow cytometry. The maximum overexpression of p53 protein was detected in the cells at the S phase. These results indicated that the nuclear accumulation of the p53 protein, especially the staining pattern, was a potentially useful prognostic factor for osteosarcoma. However our study did not show any clear correlation between either the growth pattern or the morphological type of osteosarcoma and the immunohistochemical results for the p53 protein.