Examines the frequency of murine double minute-2 gene (MDM2) amplifications in sarcomas and relates the findings to the antioncogene TP53 status of the tumors. Study of the human sarcoma cell lines OSA and U2OS; Probes; Southern-blot analysis; Mutation analysis of TP53; Northern-blot analysis; MDM2 overexpression; Levels of messenger RNA (mRNA).