Effect of doxorubicin on telomerase activity and apoptotic gene expression in doxorubicin-resistant and -sensitive MCF-7 cells

Date

2008-01-01

Author

Eskiocak, Ugur
Iseri, Ozlem Darcansoy
Kars, Meltem Demirel
Bicer, Atilla
Gündüz, Ufuk

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This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Background: Dose-and time-dependent effects of doxorubicin on telomerase activity ( TA) and expression levels of hTERT, Bcl-2, Bcl-x(L) and Bax were investigated in doxorubicin-resistant and -sensitive MCF-7 cells. Methods: Doxorubicin-resistant MCF-7/R was developed from sensitive MCF-7 breast carcinoma cell line and acquired resistance was demonstrated by XTT and mRNA analysis of MDR1 and MRP1 genes. Expression levels were determined by RT-PCR. Newly developed rapid and simple TRAP-silver staining assay was used to assess TA levels. Results: Doxorubicin-selected MCF-7 cells were 107-fold resistant to the drug and overexpress MDR1 and MRP1 genes. 72 h doxorubicin incubation caused a decrease in TA in parallel with a small decrease in hTERT level in both sensitive and resistant cells. Bcl-2 expression level decreased upon doxorubicin application in sensitive cells. However, the Bcl-x(L) level increased in sensitive cells after 72 h of doxorubicin incubation. Conclusion: This report demonstrates the inhibitory effects of doxorubicin on TA in both resistant and sensitive MCF-7 cells possibly through modulation of the apoptotic pathway genes. Copyright (C) 2008 S. Karger AG, Basel.

Subject Keywords

Doxorubicin, Telomerase, Bcl-2, Bcl-X(L), Bax, MCF-7, MDR

URI

https://hdl.handle.net/11511/31459

Collections

Graduate School of Natural and Applied Sciences, Article