Fig. 4.

Isocitrate dehydrogenase 1 (IDH1) knockdown significantly promoted MDA-MB-231 cell motility. a Expression levels of IDH1 were examined in eight breast cancer cell lines: HER2, human epidermal growth factor receptor 2; TNBC, triple negative breast cancer. b After siRNA transfection with si-IDH1#1, the expression levels of IDH1 were examined in MDA-MB-231 cells through western blotting: N.C, scramble control. c Proliferation assay was performed in MDA-MB-231 cells transfected with scramble control and si-IDH1#1. d Wound healing assay was used in MDA-MB-231 cells transfected with si-IDH1#1 and scramble control. Relative migration ability was quantified by calculating the open wound length (right panel). e Invasion ability was assessed using the Transwell assay in MDA-MB-231 cells with si-IDH1#1 and scramble control. The cell images of a representative experiment are shown. f Values quantified using Ascent software are shown. Data are reported as the number of invading cells relative to the control (means ± standard deviation (S)). g and h Expression levels of epithelial–mesenchymal transition (EMT)-related markers were examined in MDA-MB-231 cells transfected with si-IDH1#1 and scramble control, through western blotting and real-time qPCR