Author(s)

Roghayeh Tofigh¹, Saeedeh Akhavan², Nastaran Tarban³, Amin Ebrahimi Sadrabadi⁴, Arsalan Jalili⁵, Kaykhosro Moridi⁶, Sara Tutunchi^7*

¹Department of Animal Biology, Tabriz University, Tabriz, Iran.
²Department of Biology, School of Basic Sciences, Science and Research Branch, Islamic Azad University (IAU), Tehran, Iran.
³Department of Biology, Kish International Campus, University of Tehran, Kish, Iran.
⁴Department of Cell Engineering, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran.
⁵Department of Stem Cells and Developmental Biology at Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran.
⁶Department of Biology, Faculty of Advanced Sciences and Technology, Pharmaceutical Sciences Branch, Islamic Azad University (IAUPS), Tehran, Iran.
⁷Department of Medical Genetics, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.

miRNAs play an important regulatory role in variety of cellular functions and several diseases, including cancer. MicroRNA-21 (miR-21) is overexpressed in almost all types of human cancers. Studies revealed that the knockdown of miR-21 results in reduced tumor cell growth, cell cycle arrest and cell apoptosis. In this study, we evaluated the effect of doxorubicin on miR-21 expression in mcf-7 breast cancer cells. miRNA was extracted from mcf-7 cells treated with doxorubicin and untreated cells using miRNeasy Kit (Qiagen) according to the manufacturer’s instructions. cDNA synthesis was performed using miScript II RT Kit (Qiagen) and Real Time-PCR was performed using Real Q Plus 2x Master Mix Green-(Ampliqon, Denmark). The relative expression of miR-16 and miR-21 was calculated using comparative Ct method. All tests were run in triplicate to minimize the experimental errors. Samples with a Ct > 37 were excluded from the analysis. Statistically, a significant decrease in cell proliferation of mcf-7 cells was found in doxorubicin group compared with control groups 24 hours after transfection, dose dependently (p value< 0.001). After 24 hours, Doxorubicin (100 μm) significantly decreased miR-21 expression in mcf-7 cells (p = 0.0001). Also, the expression of caspase 9 significantly increased after Doxorubicin (100 μm) treatment (p = 0.0003). Together, these findings indicate that miR-21 plays a key role in regulating cell apoptosis in mcf-7 cells and may serve as a target for effective therapies.

miR-21, mcf-7 Cells, Caspase 9, Cancer

Tofigh, R. , Akhavan, S. , Tarban, N. , Sadrabadi, A. , Jalili, A. , Moridi, K. and Tutunchi, S. (2017) Doxorubicin Induces Apoptosis through down Regulation of miR-21 Expression and Increases miR-21 Target Gene Expression in MCF-7 Breast Cancer Cells. International Journal of Clinical Medicine, 8, 386-394. doi: 10.4236/ijcm.2017.86036.