Fig. 3: miR-337-3p prevented EMT of 4T1 cells induced by NE.

a Heat map showing significantly changed (P < 0.05, two-tailed Student’s t-test) miRNAs between the control group and stress group. b Pie chart showing the number of upregulated and downregulated genes in Fig. 3a. c Volcano plots showing the specific seven miRNAs with |lg FC| > 1 and P < 0.05. d RT-qPCR analysis of microRNAs as listed in the figure were carried out in 4T1 cells treated with 10 µM NE for 48 h (n = 3). Relative miRNA levels were determined by the ΔΔ Ct method using U6 for internal cross-normalization. e The transfection efficacy of the overexpression by miR-337-3p mimics in 4T1 cells was confirmed by RT-qPCR analysis (n = 3). Relative miRNA levels were determined by the ΔΔCt method using U6 for internal cross-normalization. f, g miR-337-3p-mi or NC-mi were transfected into 4T1 cells cultured with 10 µM NE. After 48 h, the EMT related protein were detected by immunofluorescent staining (n = 3). E-cadherin and vimentin are shown in red and green, respectively, while cell nucleus is shown in blue. The fluorescence intensity was quantified and shown in histogram. h–k miR-337-3p-mi or NC-mi were transfected into 4T1 cells cultured with 10 µM NE. After 48 h, the expression level of E-cadherin and vimentin were detected by western blot (n = 3). The intensity of the bands for E-cadherin and vimentin was normalized to GAPDH and shown in histograms. Data are shown as the mean ± SD; *P < 0.05; ***P < 0.001.