Deregulation of miR-۲۱ and miR-۱۵۵ and their putative targets after silibinin treatment in T۴۷D breast cancer cells

Objective(s):MicroRNAs (miRNAs) are a class of short RNAs that control the biological processes including cell proliferation, apoptosis and development. Aberrant expression of miRNAs was determined in the different stages of tumor development and metastasis. To study the effect of silibinin on miRNAs expression, we evaluated quantitative expression of miR-۲۱ and miR-۱۵۵ as two oncomiRs and several potential targets in silibinin-treated T۴۷D cells. Materials and Methods:The rate of proliferation and apoptosis was measured in silibinin-treated and untreated cells. The expression levels of miR-۲۱ and miR-۱۵۵ were evaluated in T۴۷D cells treated with silibinin (۱۰۰ µg/ml). Also, their putative targets were predicted in apoptotic pathways using multiple algorithms; as a confirmation, the transcription level of APAF-۱, CASP-۹ and BID was evaluated. Results:In silibinin-treated cells, death was occurred in a dose and time-dependent manner. miR-۲۱ and miR-۱۵۵ was downregulated in cells treated with silibinin (۱۰۰ µg/ml). It is noticeable that the expression of their potential targets including CASP-۹ and APAF-۱ was increased in silibinin-treated cells after ۴۸ hr. Conclusion:Our findings showed a correlation between the expression of miR-۲۱ and miR-۱۵۵ and apoptosis in silibinin treated T۴۷D cells. It seems that miRNAs such as miR-۲۱ and miR-۱۵۵ were regulated by silibinin. Also, increase in the transcript level of APAF-۱ and CASP-۹ after downregulation of miR-۲۱ and miR-۱۵۵ might indicate that these genes were targeted by aforementioned miRNAs in T۴۷D cells.

Keywords:

Apoptosis , miR-۲۱ , miR-۱۵۵ , Silibinin , T۴۷D cells