miR‐99a directly targets the mTOR signalling pathway in breast cancer side population cells

Z. Yang; Y. Han; K. Cheng; G. Zhang; X. Wang

doi:10.1111/cpr.12146

journal article Oct 27, 2014

miR‐99a directly targets the mTOR signalling pathway in breast cancer side population cells

Z. Yang

Cell Proliferation Vol. 47 No. 6 pp. 587-595 · Wiley

View at Publisher Save 10.1111/cpr.12146

Abstract

AbstractObjectivesmiR‐99a has been reported to function as a tumour suppressor in breast cancer. However, its role in the regulation of breast cancer stem cell (CSC) phenotype has up to now remained unknown.Materials and methodsIn this study, we isolated the side population (SP) cells by staining cultured MCF‐7 and MDA‐MB‐231 cells with fluorescent DNA‐binding dye Hoechst 33342, then by flow cytometric sorting. Next, we detected expression of miR‐99a in the SP cells compared to non‐SP cells using real‐time PCR, and explored effects of miR‐99a on the CSC phenotype of the breast cancer cells, including sphere formation, self‐renewal, tumourigenicity and cell migratory capability.ResultsWe found that expression of miR‐99a was down‐regulated in the SP cells compared to non‐SP cells. Restoration of expression of miR‐99a inhibited cell migration and invasion, reduced sphere formation of breast SP cells in vitro, and suppressed tumour growth in vivo. Finally, bioinformatic prediction suggested the oncogene, mammalian target of rapamycin (mTOR) – a downstream effector of the PI3K/AKT signalling pathway, was a target gene of miR‐99a in SP cells. Further, quantitative RT‐PCR and western blot assays identified that overexpression of miR‐99a suppressed expression of mTOR and its downstream gene, HIF‐1α.ConclusionCollectively, these data suggest that miR‐99a reversed the breast cancer malignant CSC phenotype, probably by targeting the mTOR signalling pathway.

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References

35

[1]

10.3322/caac.20107

[2]

10.3322/caac.21166

[3]

10.1073/pnas.252462599

[4]

10.1146/annurev.med.58.062105.204854

[5]

10.1073/pnas.0530291100

[6]

10.1158/0008-5472.can-05-0626

[7]

10.1002/hep.21227

[8]

10.1038/sj.bjc.6605668

[9]

10.1523/jneurosci.23-33-10703.2003

[10]

10.1073/pnas.1133179100

[11]

10.1158/1535-7163.mct-10-0108

[12]

10.3389/fgene.2014.00054

[13]

10.3892/br.2013.109

[14]

10.1016/j.biocel.2012.08.022

[15]

10.1016/j.cell.2009.07.011

[16]

10.1371/journal.pgen.1002751

[17]

10.1158/1078-0432.ccr-11-0071

[18]

10.1371/journal.pone.0092099

[19]

10.1084/jem.183.4.1797

[20]

10.1007/s13277-012-0383-6

[21]

10.1158/0008-5472.can-10-3320

[22]

10.1016/j.ccr.2008.10.016

[23]

10.1158/0008-5472.can-07-2249

[24]

Centers for Disease Control and Prevention (CDC) "Improved national prevalence estimates for 18 selected major birth defects – United States, 1999–2001" MMWR Morb. Mortal. Wkly Rep. (2006)

[25]

10.1016/j.bbrc.2008.03.120

[26]

10.1016/j.ijbiomac.2014.02.030

[27]

10.1371/journal.pone.0031032

[28]

10.1016/j.devcel.2008.05.009

[29]

10.2174/138920112802502114

[30]

10.1016/j.cell.2008.03.027

[31]

10.1074/jbc.c800074200

[32]

10.4331/wjbc.v5.i1.40

[33]

10.1038/srep03230

[34]

10.7150/thno.7851

[35]

10.1016/j.bbcan.2012.04.008

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Details

Published: Oct 27, 2014
Vol/Issue: 47(6)
Pages: 587-595
License: View

Authors

Z

Z. Yang