Ab179821

The following antibodies were used for western blotting: rabbit monoclonal anti-CD24 (1:500, catalog number ab179821, Abcam, MA, USA), rabbit monoclonal anti-CD44 (1:500, catalog number ab189524, Abcam), rabbit recombinant multiclonal anti-CD133 (1:800, catalog number ab278053, Abcam), mouse monoclonal anti-Nanog (1:1000, catalog number ab173368, Abcam), rabbit monoclonal anti-OCT4 (1:500, catalog number ab200834, Abcam), mouse monoclonal anti-SOX2 (1:1000, catalog number ab79351, Abcam), rabbit polyclonal anti-DLG5 (1:1000, catalog number ab231283, Abcam), rabbit polyclonal anti-PRDM16 (1:1000, catalog number ab106410, Abcam), mouse monoclonal anti-ErbB-2 (1:500, catalog number sc-33684, Santa Cruz Biotechnology, CA, USA), and mouse monoclonal anti-β-actin (1:1000, catalog number A5441, Sigma-Aldrich, MO, USA). Other primary antibodies and secondary antibodies and experimental procedures for immunoblotting are provided in the supplementary experimental procedures^{10 (link)}.

The protein samples from TNBC cell lines were extracted using RIPA lysis buffer (Beyotime, Shanghai, China) supplemented with 1 × Halt protease and phosphatase inhibitor cocktail (Thermo Scientific). The equal amount of protein (10‐20 µg) was separated on a 10% SDS‐PAGE gel, transferred to a 0.45 µm immobilon PVDF membrane (Millipore, CA, USA), and then blocked with 5% BSA. After incubation with primary antibodies (Abs) at 4 °C overnight, protein bands were further incubated with HRP‐conjugated secondary antibody. Unless otherwise specified, Abs were diluted 1:1000. The protein lanes were illuminated by an enhanced chemiluminescence substrate (Beyotime) and exposed in the ImageQuant LAS 4000 system (GE Healthcare, IL, USA). The GAPDH was used as an internal reference. The rabbit primary polyclonal antibodies against ALDH1A3 (ab129815), THOC2 (ab129485), and cleaved caspase‐9 (ab2324) were purchased from Abcam (MA, USA). The rabbit monoclonal antibodies against CD44 (ab189524), CD24 (ab179821), CD133 (ab216323), THOC5 (ab137051), OCT4 (ab181557), NANOG (ab214549), SOX2 (ab92494), cleaved caspase‐3 (ab32042), cleaved PARP1 (ab32064), and GAPDH (ab181602, dilution ratio 1:2000) were purchased from Abcam. The antirabbit secondary antibody (7074) was purchased from Cell Signaling Technology (MA, USA).