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
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 sensitive and resistant cells were exposed to 200- and 800 cGy gamma radiation, and proliferation was examined by XTT {2,3-bis(2-methoxy-4-nitro-5-sulfopheny1)-5-Rphenylamino)carbonyl]-2H-tetrazolium hydroxide) assay. The results showed that Prednisone- and melphalan-resistant RPMI-8226 cells were also cross-resistant to 200 and 800 cGy gamma radiation application, while vincristine-resistant cells did not show resistance. On the other hand, Prednisone-, vincristine- and melphalan-resistant U-266 cells showed cross-resistance to 200- and 800 cGy gamma radiation application. These results demonstrated that MM cells resistant to anticancer agents respond to radiation in different levels. These findings may be important in the clinical applications of radiation therapy in the treatment of vincristine resistant MM.


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BARAN, YUSUF; Bielawski, Jacek; Gündüz, Ufuk; Ogretmen, Besim (2011-10-01)
Purpose Drug resistance presents a major obstacle for the treatment of some patients with chronic myeloid leukemia (CML). Pro-apoptotic ceramide mediates imatinib-induced apoptosis, and metabolism of ceramide by glucosylceramide synthase (GCS) activity, converting ceramide to glucosyl ceramide, might contribute to imatinib resistance. In this study, we investigated the role of ceramide metabolism by GCS in the regulation of imatinib-induced apoptosis in drug-sensitive and drug-resistant K562 and K562/IMA-0....
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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...
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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...
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Çakmak, Neşe; Gündüz, Ufuk; Department of Biology (2013)
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 pat...
Differential oncogene-related gene expressions in myeloma cells resistant to prednisone and vincristine
Mutlu, Pelin; Gündüz, Ufuk (2012-10-01)
Multidrug resistance in cancer may arise due to alterations in gene expression. In this study, sublines of drug-resistant multiple myeloma (MM) cells, namely RPMI-8226 and U-266, were examined for their differential oncogene-related gene expression levels and the relations to drug resistance were analyzed. Drug resistance was induced by application of the prednisone or vincristine using stepwise dose increments. XTT cytotoxicity assay was used for determination of resistance levels. Microarray analysis was ...
Citation Formats
P. Mutlu, A. U. Ural, F. Avcu, B. Dirican, M. Beyzadeoglu, and U. Gündüz, “Effect of cobalt-60 (gamma radiation) on multidrug-resistant multiple myeloma cell lines,” CELL BIOLOGY INTERNATIONAL, pp. 721–725, 2011, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/31511.