PB1696 EVALUATION OF TUMOR CELL SENSITIVITY TO DAUNORUBICIN USING WST1 TEST IN ACUTE MYELOBLASTIC LEUKEMIA PATIENTS
Authors: M. Kolesnikova, A. Sen’kova, M. Zenkova, T. Pospelova
Journal: HemaSphere (2019)

Background: In recent years the MTT test for the assessment of the sensitivity of tumor cells to cytotoxic drugs in leukemia patients were used. In present study, the possibility of the WST1 test as a screening method of drug sensitivity of tumor cells of leukemia patients using peripheral blood and bone marrow samples was evaluated. Aims: The aim of this work was to study the effectiveness of the WST1 test for the initial estimation of the sensitivity of tumor cells to daunorubicin in vitro and prediction of the treatment response of patients with acute myeloblastic leukemia. Methods: The study included 42 patients with acute myeloblastic leukemia (AML). The average age of the patients was 53.3 ± 12.7 years. Leukemia cells were obtained from peripheral blood and bone marrow of patients. The sensitivity of tumor cells of patients with AML to daunorubicin in vitro using the WST1 test was made prior to initiating of cytotoxic therapy. Confirmation of multidrug resistance by evaluation of MDR1 mRNA expression levels in tumor cells of AML patients was performed on bone marrow and/or peripheral blood samples using quantitative real‐time reverse transcription‐polymerase chain reaction (real‐time qPCR). In all patients, the diagnosis was confirmed by the study of myelogram, flow cytofluorimetry, immunocytochemistry, cytogenetic analysis, as well as standard laboratory and instrumental studies that are included in the standard examination of patients with leukemia. Based on immunopenotyping and cytogenetic analysis, each patient was assigned to a risk group and prognosis. The obtained results were compared with the clinical and hematological response of these patients to cytotoxic therapy, as well as with the MDR1 mRNA expression level. Also we evaluated the survival of leukemia patients depending on the sensitivity to daunorubicin and MDR1 mRNA expression levels in tumor cells of AML patients. All statistical analyses were done with computer software MS Excel, OriginPro 7.5, Statistica 10.0. Results: Regardless of the class of chemotherapeutic drugs administered to the patients, the survival rate was higher in the group of patients with high sensitivity to daunorubicin and low expression levels of the MDR1 mRNA in tumor cells. Patients received daunorubicin within the “7 + 3” regimen (7 days of cytarabine and 3 days of daunorubicin) showed a high correlations (r = 0.8, p &lt;0.05) between the expression levels of MDR1 mRNA and sensitivity to daunorubicin, moderate correlations (r = 0.63, p &lt; 0.05) between the response to chemotherapy and sensitivity to daunorubicin, and a moderate correlations between the prediction (r = 0.48, p &lt; 0.05) and the risk group (r = 0.49, p &lt; 0.05) and sensitivity to daunorubicin. It is important to note that a high correlations (r = 0.86, p &lt; 0.05) was found between the expression levels of MDR1 mRNA and the response to therapy. Summary/Conclusion: The obtained data demonstrate that the WST1 test can be effectively used as a screening method for the initial assessment of the sensitivity of tumor cells to daunorubicin in vitro and prediction of the response to treatment of AML patients.