MESSENGER-RNA EXPRESSION, MEASURED BY QUANTITATIVE REVERSE-TRANSCRIPTASE POLYMERASE-CHAIN-REACTION, OF 5 PUTATIVE DRUG-RESISTANCE PARAMETERS, IN NORMAL AND LEUKEMIC PERIPHERAL-BLOOD AND BONE-MARROW

Using a quantitative reverse transcriptase PCR assay, the mRNA express ion of five putative drug resistance-related genes were assessed in no rmal peripheral (n = 14) and bone marrow (n = 4) mononuclear cells fro m healthy donors and patients with acute myeloid leukaemia (n = Il). T he mRNA levels of MDR1, the multidrug resistance-associated protein an d glutathione-S-transferase pi were equally expressed in both compartm ents. Bcl-2 mRNA was slightly higher in the leukaemic marrow samples. However, topoisomerase II alpha mRNA levels were found to be much high er in normal and leukaemic marrow cells compared to peripheral blood ( p < 0.01), which may, in part, reflect the different proliferation pat tern of the mononuclear cells in the two compartments. Such findings c ould be important for researchers using bulk assays in a mix of sample s from peripheral blood or bone marrow to investigate prognostic facto rs in patients with leukaemia.