Multidrug Resistance Associated Genes MRP1, MRP2 and MRP3 in Primary and Anthracycline Exposed Breast Cancer

• Published in: Anticancer research 2004-09, Vol.24 (5A), p.2931-2939
• Main Authors: FANEYTE, Ian F, KRISTEL, Petra M. P, VAN DE VIJVER, Marc J
• Format: Article
• Language: English
• Subjects: Anthracyclines - administration & dosage; Anthracyclines - pharmacology; Antineoplastic Combined Chemotherapy Protocols - administration & dosage; Antineoplastic Combined Chemotherapy Protocols - pharmacology; Biological and medical sciences; Breast Neoplasms - drug therapy; Breast Neoplasms - genetics; Breast Neoplasms - metabolism; Breast Neoplasms - surgery; Cell Line, Tumor; Clinical Trials, Phase II as Topic; Cyclophosphamide - administration & dosage; Disease-Free Survival; Drug Resistance, Neoplasm; Epirubicin - administration & dosage; Fluorouracil - administration & dosage; Gene Expression - drug effects; Genes, MDR - drug effects; Gynecology. Andrology. Obstetrics; Humans; Immunohistochemistry; Mammary gland diseases; Medical sciences; Membrane Transport Proteins - biosynthesis; Membrane Transport Proteins - genetics; Multidrug Resistance-Associated Proteins - biosynthesis; Multidrug Resistance-Associated Proteins - genetics; Multidrug Resistance-Associated Proteins - metabolism; Neoadjuvant Therapy; RNA, Messenger - biosynthesis; RNA, Messenger - genetics; Tumors
• ISSN: 0250-7005; 1791-7530

Background: Multidrug resistance associated proteins MRP1, MRP2 and MRP3 confer in vitro multidrug resistance. We investigated their role in breast cancer resistance to anthracycline-based chemotherapy. Materials and Methods: Using real-time reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC), the expression of MRP1 - 3 was quantified in nine breast cancer cell lines and 30 breast carcinoma samples. Results: MRP1 - 3 mRNA was detectable in all breast cancer cell lines and tumor samples. No increase of expression was detected between untreated carcinoma and post-neoadjuvant anthracycline treatment tumor samples. IHC failed to detect the proteins. MRP1 - 3 expression was not associated with tumor response to treatment or with outcome. Conclusion: MRP1 - 3 are expressed in breast cancer cells, but are not detected with IHC. We have found no evidence linking these proteins to clinical drug resistance in a small but well-documented series of breast cancer samples.