Affiliations: Division of Medical Biotechnology, National Institute
of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran | Genetics of Non-communicable Diseases Research Center,
Zahedan University of Medical Sciences, Zahedan, Iran | Department of Genetics, School of Medicine, Zahedan
University of Medical Sciences, Zahedan, Iran
Note: [] Corresponding author: Frouzandeh Mahjoubi, Division of Medical
Biotechnology, National Institute of Genetic Engineering and Biotechnology
(NIGEB) Pajoohesh Blvd. Tehran-Karaj Highway, 17th Km, Tehran, Iran. Tel.: +98
21 44580389; Fax: +98 21 44580399; E-mail: frouz@nigeb.ac.ir
Abstract: A major problem in the treatment of breast cancer is the development
of resistance to chemotherapeutic agents. Although the role of multidrug
resistance 1 (MDR1) and multidrug resistance associated protein 1 (MRP1) in
inducing drug resistance in many cancers has been widely investigated the
clinical significance of expression of these genes in breast cancer remains
unclear and the data is still controversial. We investigated the expression of
MDR1 and MRP1 in breast cancer patients as well as the possible correlation
between MDR1 and MRP1 and clinical response to chemotherapy. In the present
study, MDR1 and MRP1 gene expression were investigated by real time reverse
transcription polymerase chain reaction (RT-PCR) assay in 54 breast cancer
tumors and in corresponding adjacent normal tissues before neoadjuvant
chemotherapy. The expression level of MDR1 and MRP1 were significantly higher
in breast tumors than normal breast tissues. Although a significant
relationship was found between the MRP1 expression and response to treatment no
association was observed between MDR1 expression and response to treatment.
MDR1 and MRP1 expression levels have been shown to be independent of tumor
size, histological grade and the status of progesterone or estrogen
receptor.
Keywords: Multidrug resistance, real time PCR, breast cancer, MDR1, MRP1
