MULTIDRUG-RESISTANCE GENE TRANSCRIPT LEVEL, AND P-GLYCOPROTEIN EXPRESSION IN PEDIATRIC MALIGNANT MESENCHYMAL TUMORS

Twenty-four malignant mesenchymal tumor specimens were analysed for. h uman multidrug resistance (MDRI) gene transcript levels using Northern and slot blot techniques. The presence of P-glycoprotein was assessed in 12 of the 24 samples by immunohistochemistry using the monoclonal antibody (MAb) C219. Ina eased MDRI transcript levels were found in 2 (8.3%), while, using immunohistochemistry, 2 samples were positive and 3 faintly positive (41.6%). Over-all, elevated P-glycoprotein ol MDRI transcript levels were found in tumours of 6 patients, 3 of whom ale dead. The relationship to MDRI expression and subsequent resistance to chemotherapy has to be established.