Expression of miRNAs Targeting mTOR and S6K1 Genes
of mTOR Signaling Pathway Including miR-96, miR-557,
and miR-3182 in Triple-Negative Breast Cancer
Received: 8 February 2018 /Accepted: 23 April 2018
Springer Science+Business Media, LLC, part of Springer Nature 2018
Abstract Triple-negative breast cancer (TNBC) is a highly aggressive form of breast cancer.
Aberrant expression of genes in mTOR pathway and their targeting miRNAs plays an
important role in TNBC. The aim of this study was to determine the expression of mTOR
and S6K1 and their targeting miRNAs in breast cancer cell lines and clinical samples. miRNAs
targeting 3′-UTR of mTOR and S6K1 mRNAs were predicted using bioinformatic algorithms.
MDA-MB-231, MCF-7, and MCF-10A as well as 20 TNBC samples were analyzed for gene
and miRNA expression using quantitative real-time PCR (RT-qPCR). A receiver operating
characteristic (ROC) curve analysis was performed for evaluation of candidate miRNAs as
diagnostic biomarkers. miR-96 and miR-557 targeting mTOR and S6K1 mRNAs, respectively,
were selected, and miR-3182 was selected as the miRNA targeting both genes. The miRNAs
were down-regulated in cell lines, while their target mRNAs were up-regulated. Similar
findings were observed in clinical samples. The ROC curve analysis revealed decline in
expression of these miRNAs. We suggest that miR-96, miR-557, and miR-3182 can be used
as inhibitory agents for mTOR and S6K1 in TNBC-targeted therapy.
Keywords Breast cancer
Appl Biochem Biotechnol
Maliheh Paknejad and Samira Mohammadi-Yeganeh contributed equally to this work.
* Maliheh Paknejad
* Samira Mohammadi-Yeganeh