Reversal of multidrug resistance in mcf-7 breast adenocarcinoma cell line by silencing interleukin 6 with RNA interference

Download

index.pdf

Date

2013

Author

Çakmak, Neşe

Metadata

Show full item record

Item Usage Stats

310
views

99
downloads

Multidrug resistance (MDR) in cancer is characterized by development of resistance to several unrelated drugs upon long time administration of a certain type of chemotherapeutic agent. In doxorubicin resistant MCF-7 cell line, resistance is developed mainly by upregulation of MDR1 gene which encodes an ABC transporter protein known as P-glycoprotein. Interleukin 6 (IL-6) is a cytokine which acts as a growth factor for certain cell types including some cancer cells. IL-6 is found at high levels in cancer patients having poor prognosis and resistance to certain chemotherapeutic agent. It is known that in MCF7 cell line, IL-6 induces overexpression of MDR1 gene by activating its transcription factor, C/EBPβ and confers resistance against Doxorubicin. In this study, the aim is silencing IL6 and to see the effects on MDR. Effects of IL-6 silencing on the levels of IL6, MDR1 and MRP1 genes are determined by qRT-PCR. Further confirmation of IL6 silencing is done by checking secreted IL-6 amount in cell culture media. Drug accumulation assay is done for evaluation of IL6 silencing on P-gp function. Moreover, to show that silencing of this particular gene sensitizes cells to chemotherapeutic drug Doxorubicin, XTT cytotoxicity assay is done. Results indicate that IL6 is successfully silenced by applying RNA interference which is observed by 36% decrease in IL-6 level to cell culture media. In correlation, IL6 mRNA level decreased 0.5 fold 24 hours after treatment. In addition, MDR1gene is downregulated by 45% as a consequence of interruption of IL-6 signaling in cell. MRP1, another ABC transporter coding gene, which is not connected to IL-6 signaling pathway, is not affected by silencing showing that reversal of multidrug resistance is only dependent on decreased MDR1 expression. Cytotoxicity assays show that cells are sensitized to Doxorubicin in an extent of 65% It is demonstrated that silencing IL6 gene makes Doxorubicin resistant MCF-7 cells significantly more susceptible to drug.

Subject Keywords

Multidrug resistance., Drug resistance in cancer cells., Doxorubicin., Gene silencing.

URI

http://etd.lib.metu.edu.tr/upload/12616111/index.pdf
https://hdl.handle.net/11511/22759

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

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...
Effect of cobalt-60 (gamma radiation) on multidrug-resistant multiple myeloma cell lines Mutlu, Pelin; Ural, A. Ugur; Avcu, Ferit; Dirican, Bahar; Beyzadeoglu, Murat; Gündüz, Ufuk (2011-07-01) Emergence of resistance to chemotherapy and radiotherapy is a major obstacle for the successful treatment of MM (multiple myeloma). Prednisone, vincristine and melphalan are commonly used chemotherapeutic agents for the treatment of MM. In the current study, we examined the presence of possible cross-resistance between these drugs and gamma (gamma) radiation. Prednisone, vincristine and melphalan resistant RPMI-8226 and U-266 MM cells were generated by stepwise increasing concentrations of the drugs. The se...
Synthesis of poly (dl-lactic-co-glycolic acid) coated magnetic nanoparticles for anti-cancer drug delivery Tansık, Gülistan; Gündüz, Ufuk; Department of Biology (2012) One of the main problems of current cancer chemotherapy is the lack of selectivity of anti-cancer drugs to tumor cells which leads to systemic toxicity and adverse side effects. In order to overcome these limitations, researches on controlled drug delivery systems have gained much attention. Nanoscale based drug delivery systems provide tumor targeting. Among many types of nanocarriers, superparamagnetic nanoparticles with their biocompatible polymer coatings can be targeted to an intented site by an extern...
Reversal of multidrug resistance by synthetic and natural compounds in drug-resistant MCF-7 cell lines Kars, Meltem Demirel; Iseri, Ozlem Darcansoy; Gündüz, Ufuk; Molnar, Jozsef (2008-01-01) Background: Ineffectiveness of anticancer drugs is frequently observed in cancer chemotherapy. The resistance of tumor cells to various cytotoxic drugs is defined as multidrug resistance (MDR). The purpose of this study is to investigate the potential reversal effect of some synthetic and natural chemicals on drug-resistant MCF-7 cell lines. The effects of potential MDR modulators combined with some anticancer drugs were also studied. Methods: Flow cytometry, MTT cytotoxicity assays and checkerboard combina...
INVESTIGATION OF CLONAL EVOLUTION IN CAPECITABINE RESISTANT CACO-2 AND IRINOTECAN RESISTANT HT-29 CELL LINES BY USING CELLULAR BARCODING TECHNOLOGY Danışık, Nurseda; Acar, Ahmet; Özen, Can; Department of Biotechnology (2022-10-31) The development of drug resistance in tumor cells is one of the biggest problems currently in the clinic. As the pace of drug discovery slows and each new drug becomes increasingly expensive to bring to market, it is becoming clearer that better model systems and an understanding of drug resistance mechanisms are needed for second-line therapies. The overall aim of this project is to investigate the clonal evolution and drug resistance in colorectal cancer cell lines Caco-2 and HT-29 by using cellular barco...

Citation Formats

N. Çakmak, “Reversal of multidrug resistance in mcf-7 breast adenocarcinoma cell line by silencing interleukin 6 with RNA interference,” M.S. - Master of Science, Middle East Technical University, 2013.