Anti nr4a1

All breast cancer cell lines were treated under the appropriate conditions and lysed in NP-40 lysis buffer, after which their protein concentrations were estimated using the Pierce BCA Protein Assay Kit (Thermo Scientific, Waltham, MA, USA). Each lysate was separated by 8–12% SDS polyacrylamide gel electrophoresis and then transferred to Immobilon-P PVDF transfer membranes (Merck Millipore, Burlington, MA, USA). Immunoreactive bands were detected using suitable primary antibodies and the appropriate HRP–conjugated secondary antibodies. Bands were visualized using the SuperSignal West Pico Chemiluminescent Substrate Kit (Thermo Scientific, Waltham, MA, USA). Anti-NR4A1 (ab13851, Abcam, Cambridge, UK), anti-Caspase-7 (#12827, Cell Signaling Technology, Danvers, MA, USA), anti-Caspase-9 (#9508, Cell Signaling), anti-PARP (#9542, Cell Signaling), anti-Src (#2110, Cell Signaling), anti-phospho-Src (#6943, Cell Signaling), anti-MEK1/2 (#4694, Cell Signaling), anti-phospho-MEK1/2 (#9154, Cell Signaling), anti-ERK1/2 (#9102, Cell Signaling), anti-phospho-ERK1/2 (#9101, Cell Signaling), anti-HDAC1 (ab7028, Abcam), and anti-β-actin (ab6276, Abcam) were used to detect proteins.