Figure 3
Re-expression of miRNA-375 in TamR cells sensitizes cells to tamoxifen, inhibits invasion and reverses EMT-like properties while knockdown of miRNA-375 promotes resistance to tamoxifen in WT cells. (a) qRT–PCR data validation of the downregulation of miRNA-375 in TamR cells compared with WT cells, normalized to RNU44 and RNU48, which was obtained from miRNA microarrays. The results are shown as an average of four biological and three technical replicates. (b) Sensitizer effect of miRNA-375, using precursor molecules, on the TamR phenotype of cells as measured by Cell Titer Glo Luminescent Cell Viability assay analysis. (c) Sensitizer effect of miRNA-375, using an overexpression vector, on the TamR phenotype of cells. The results are shown as an average of three biological and four technical replicates. (d) Transfection with miRNA-375 inhibitor promotes resistance to tamoxifen. (e) miRNA-375 re-expression reduces cell invasion capacity of TamR MCF-7 cells in a Matrigel invasion chamber assay. The results are shown as an average of three biological and three technical replicates. (f) qRT–PCR data show that re-expression of miRNA-375 modulates the expression of EMT markers. The results are normalized to ACTB and HPRT and are shown as an average of four biological and three technical replicates. (g) Expression of miRNA-375 is reduced in a group of mesenchymal breast cell lines compared with epithelial ones. The results are normalized to RNU44 and RNU48 and are shown as an average of two biological and three technical replicates. *P<0.05, **P<0.001, ***P<0.001, determined by a two-sided t-test. (h) Boxplot depicting the expression level of miRNA-375 in a group of 11 epithelial cell lines compared with 37 mesenchymal cell lines from the NCI60 panel.
