mRNA expression, measured by quantitative reverse transcriptase polymerase chain reaction, of five putative drug...

Using a quantitative reverse transcriptase PCR assay, the mRNA expression of five putative drug resistance-related genes were assessed in normal peripheral (n = 14) and bone marrow (n = 4) mononuclear cells from healthy donors and patients with acute myeloid leukaemia (n = 11). The mRNA levels of MDR1, the multidrug resistance-associated protein and glutathione-S-transferase pi were equally expressed in both compartments. Bcl-2 mRNA was slightly higher in the leukaemic marrow samples. However, topoisomerase II alpha mRNA levels were found to be much higher in normal and leukaemic marrow cells compared to peripheral blood (p < 0.01), which may, in part, reflect the different proliferation pattern of the mononuclear cells in the two compartments. Such findings could be important for researchers using bulk assays in a mix of samples from peripheral blood or bone marrow to investigate prognostic factors in patients with leukaemia.