U1 snrnp 70

Entinostat was provided by Syndax Pharmaceuticals, Inc. Lapatinib was purchased from ChemieTek. Small interfering RNA (siRNA) targeting FOXO3 and Bim1 were purchased from Sigma-Aldrich. The following antibodies were purchased from Cell Signaling Technology (Beverly, MA): pEGFR-Tyr1173, EGFR, pHER2-Tyr1248, HER2, pHER3-Tyr1289, HER3, pERK-Thr202/Tyr204, ERK, pAKT-Ser473, AKT, Bim1. We obtained β-actin (clone AC-15; Sigma-Aldrich, St Louis, MO), U1 snRNP70 (Santa Cruz Biotechnology, Santa Cruz, CA), Alexa Fluor 680 and 800 (Invitrogen, Carlsbad, CA), and horseradish peroxidase (HRP)-conjugated antibodies (Thermo Scientific, Rockford, IL). The following small interfering RNA oligos (Sigma-Aldrich) were used for depletion of FOXO3a or Bim1: FOXO3a #1, 5′CGAAUCAGCUGACGACAGU[dT][dT]3′; FOXO3a #2, 5′CGAUUCAUGCGGGUCCAGA[dT][dT]3′; FOXO3a #3, 5′GAAUGAGGGCUGACUGAA[dT][dT]3′; Bim1 #1, 5′GAAUGGUUAUCUUACGACU[dT][dT]3′; Bim1 #2, 5′CAGAUAUGCGCCCAGAGAU[dT][dT]3′; Bim1 #3, 5′CAUGAGUUGUGACAAAUCA[dT][dT]3′. Knockdown efficiency of single siRNAs was tested by Western blotting (Supplementary Fig. S1), and we used pooled siRNA of three target siRNAs for knockdown experiments. The scrambled siRNA was purchased from Thermo Scientific (ON-TARGETplus Non-targeting Control Pool, part number D-001810-10).