Etoposide resistance in MCF-7 breast cancer cell line is marked by multiple mechanisms

Alpsoy, Aktan
Yasa, Seda
Gündüz, Ufuk
Purpose: Acquired or intrinsic drug resistance is one of the major handicaps in the success of chemotherapy. Etoposide is a topoisomerase II poison widely used in chemotherapy. Similar to other topoisomerase inhibitors and DNA damaging agents, resistance to etoposide may arise as a result of alterations in target expression and activity, increased drug efflux and alterations in DNA damage response mechanisms. Here, we tested the involvement of such mechanisms in etoposide-resistant MCF-7 breast cancer cells.


Expression analysis of TOP2A, MSH2 and MLH1 genes in MCF7 cells at different levels of etoposide resistance
Kaplan, Esra; Gündüz, Ufuk (2012-02-01)
Purpose: Development of resistance against anti-cancer drugs is one of the major obstacles of chemotherapy in the treatment of cancer. Etoposide is a topoisomerase II alpha (TOP2A) inhibitor, which is used in the treatment of breast cancer. Alterations in the expression of drug targets or DNA repair genes are among the important resistance mechanisms against TOP2A inhibitors. In this study, expression changes in TOP2A gene and two important mismatch repair (MMR) genes MSH2 and MLH1 were examined in order to...
Development and investigation of etoposide resistance in MCF-7 Breast cancer cell line
Kaplan, Esra; Gündüz, Ufuk; Department of Biology (2010)
Failure of chemotherapy in cancer patients because of development of drug resistance is a major problem. Alterations of DNA repair mechanisms and drug targets are among the important resistance mechanisms which are developed against topoisomerase II inhibitors etoposide and doxorubicin. Modifications in the expression levels of mismatch repair (MMR) genes due to resistance to topoisomerase II inhibitors are involved in breast cancer. In this study, etoposide resistant sublines were developed from MCF7 breas...
Protein kinase D2 silencing reduced motility of doxorubicin-resistant MCF7 cells
Alpsoy, Aktan; Gündüz, Ufuk (2015-06-01)
Success of chemotherapy is generally impaired by multidrug resistance, intrinsic resistance, or acquired resistance to functionally and structurally irrelevant drugs. Multidrug resistance emerges via distinct mechanisms: increased drug export, decreased drug internalization, dysfunctional apoptotic machinery, increased DNA damage repair, altered cell cycle regulation, and increased drug detoxification. Several reports demonstrated that multidrug resistance is a multifaceted problem such that multidrug resis...
Reversal of breast cancer resistance protein mediated multidrug resistance in MCF7 breast adenocarcinoma cell line
Urfalı, Çağrı; Gündüz, Ufuk; Department of Biology (2011)
Resistance to various chemotherapeutic agents is a major problem in success of cancer chemotherapy. One of the primary reasons of development of multidrug resistance (MDR) is the overexpression of ATP binding cassette (ABC) transporter proteins. Breast cancer resistance protein (BCRP) belongs to ABC transporter family and encoded by ABCG2 gene. BCRP is mainly expressed in MDR1 (P-glycoprotein) lacking breast cancer cells. Overexpression of BCRP leads to efflux of chemotherapeutic agents at higher rates, the...
Dual function of programmed cell death 10 (PDCD10) in drug resistance
Urfali-Mamatoglu, Cagri; Kazan, Hasan Huseyin; Gündüz, Ufuk (2018-05-01)
Drug resistance, a major challenge in cancer chemotherapy, is a result of several mechanistic alterations including resistance to apoptosis. Apoptosis is a well-controlled cell death mechanism which is regulated by several signaling pathways. Alterations in structure, function, and expression pattern of the proteins involved in the regulation of apoptosis have been linked to drug resistance. Programmed Cell Death 10 (PDCD10) protein is recently associated with the regulation of cell survival and apoptosis. ...
Citation Formats
A. Alpsoy, S. Yasa, and U. Gündüz, “Etoposide resistance in MCF-7 breast cancer cell line is marked by multiple mechanisms,” BIOMEDICINE & PHARMACOTHERAPY, pp. 351–355, 2014, Accessed: 00, 2020. [Online]. Available: