Modulation of multidrug resistance gene expression in peripheral blood mononuclear cells of lung cancer patients and evaluation of their clinical significance

Multidrug resistance is one of the major obstacles to the successful treatment of non-small cell lung cancer (NSCLC). An ability to identify molecular markers of drug resistance in peripheral blood cells in order to better target treatment would therefore be extremely useful in selecting therapy protocols for patients. The aim of the present study was to evaluate whether expression of resistance genes (MDR1, MRP3 and LRP) can predict clinical outcome in NSCLC patients treated with paclitaxel and carboplatin.Peripheral blood samples were obtained from lung cancer patients before and after chemotherapy and expression of the resistance gene in polymononuclear cells was detected by real-time reverse-transcription polymerase chain reaction. The results were correlated with treatment response and overall survival, which was calculated according to the Kaplan-Meier method.MDR1 expression levels in PMNs rose rapidly within 24 h post-administration of paclitaxel and carboplatin, whereas MRP and LRP expression levels remained unchanged. However, no significant correlation was observed between MDR1 expression and the patients' survival or treatment response.Modulation of MDR1 gene expression in PMNs after lung cancer treatment with paclitaxel and carboplatin cannot be used as a prognosis marker in these patients.