EXPRESSION OF THE MDR1 GENE IN BONE AND SOFT-TISSUE SARCOMAS OF ADULTPATIENTS

The expression of the mdr1 gene was evaluated at the RNA level by nort hern and slot blot analysis, and at the protein level by immunohistoch emistry, in a total of 29 bone and 32 soft tissue sarcomas. All patien ts, mainly adults, had not received previous chemotherapy. Of the tumo urs investigated, 69% were mdr1-positive. An intermediate mdr1 express ion was observed most frequently, with the exception of osteosarcomas (high) and malignant fibrous histiocytomas (low). Detection of P-glyco protein in selected tumours revealed consistent results. However, no c onclusion can be drawn as yet regarding correlation of mdr1 expression and drug resistance in patients.