[Adaptation of reverse transcriptase polymerase chain reaction for clinical diagnosis of expression of MDR1 gene].

Chemotherapy of malignant tumors is ineffective usually because of tumor cell resistance to it. Two types of resistance are known: cell resistance to a certain drug and multiple drug resistance (MDR). MDR covers a wide spectrum of drugs with different chemical structure and mechanisms of action. The most frequent cause of MDR is hyperexpression in the plasma membrane of P glycoprotein cells, which is coded for by MDR1 gene realizing active release of many cytotoxic substances from cells (Pgp-MDR). Acquisition of MDR phenotype by patient's cells impedes therapy and is often a poor prognostic sign, and therefore testing of material from cancer patients for MDR phenotype is important for selecting tumor therapy. We adapted the reverse transcriptase polymerase chain reaction (RT-PCR) to evaluating the MDR1 gene expression in peripheral blood cells of patients with hemoblastosis, assessed its sensitivity and specificity, and carried out clinical trials with blood samples from patients with MDR. Comparison of the results of RT-PCR with the findings of other methods used for detection of Pg-MDR showed their good correlation in the majority of cases. These results recommend these method for clinical practice in patients with hemoblastosis.