Inhibited EGFR/PI3K/Akt signaling pathway in miR-361-5p mimics-transfected MDA-MB-231 TNBC cells. After the transfection of MDA-MB-231 cells with miR-361-5p mimics/NC plasmids and 48 and 72 hours of incubation in RPMI-1640 medium for qRT-PCR and western blot, respectively, mRNA and protein expression was assessed. (A) Relative expression of EGFR mRNA. (B) Relative expression of PI3K mRNA. (C) Relative expression of Akt mRNA. (D) Western blot results for RQCD1, PI3K, p-PI3K, EGFR, p-EGFR, Akt, p-Akt, and MMP-9 protein expression. (E) Relative expression of RQCD1, PI3K, p-PI3K, EGFR, p-EGFR, Akt, p-Akt, and MMP-9 expression versus GAPDH. Control: Blank group. Negative control (NC) group: Cells treated with control plasmids. Mimics group: Cells treated with miR-361-5p mimics plasmids. **p < 0.01 vs. control group. EGFR: Epidermal growth factor receptor; PI3K: Phosphatidylinositol-4,5-bisphosphate 3-kinase; Akt: Protein kinase B; TNBC: Triple-negative breast cancer; qRT-PCR: Quantitative reverse transcription polymerase chain reaction; RQCD1: Cell differentiation 1 homolog; p: phosphorylated; MMP-9: Matrix metallopeptidase 9; GAPDH: Glyceraldehyde 3-phosphate dehydrogenase; TNBC: Triple-negative breast cancer.