[p53 antioncogene abnormal in osteosarcoma].

Immunohistochemical evaluation of 24 osteosarcoma using an anti-p53 protein monoclonal antibody (Moab p53-12) showed strong positive reaction in the nuclei of tumor cells in 14 osteosarcoma (58.3%). Many studies have proved that this overexpression of p53 protein in tumor cells is associated with mutation of the p53 gene. Contrast study with DNA flow cytometry made on osteosarcoma showed that most of the p53 strongly positive tumors have higher DNA Index value than negative or slightly positive ones, though no statistically difference existed between two groups. Southern blot hybridization of p53 gene was also made in osteosarcomas. 5 of 20 cases (20%) had the structural changes of p53 gene. 3 of them were part or whole deletion of the gene. 2 of them had the extra-band, indicating the rearrangement of the gene.