Expression of LRP Gene in Breast Cancer Patients Correlated with MRP1 as Two Independent Predictive Biomarkers in Breast Cancer.

Background: Breast cancer is the most common malignancy in women. Multidrug resistance (MDR) is still a great obstacle of breast cancer chemotherapy. We have previously shown that multidrug resistance-associated protein 1 (MRP1) is associated with response to neoadjuvant chemotherapy. The lung resistance-related protein (LRP) is identified as a prognostic marker and response to treatment factor which has been studied mainly in hematological malignancy and leukemia. In this study, we aimed to analyze LRP expression and possible correlation between the expression level of this gene with MRP1 as a candidate marker for chemotherapy resistance. Materials and Methods: We collected 54 breast tumors and adjacent normal tissues from Iranian breast cancer patients and Real time RT-PCR was employed to measure the gene expression level in our samples. Results: MRP1 and LRP expression level were significantly lower in tumor tissues of the patients responding to chemotherapy compared to non-responding patients. No relation between the expression level of either of these genes and clinicopathology markers was found. Conclusion: Our results suggest that LRP gene expression is correlated to MRP1 in human breast cancer cells and may affect the clinical response to treatment.