Fig. 5: EPZ and anti-HER2 combination elicits robust effect in vitro.

a Representative images (left) and quantification (right) of soft agar assay with SKBR3 or clonogenic assay with UACC812 treated with DMSO, EPZ (1 µM), lapatinib (lap; 20 nM), or the combination of both. Data are expressed as mean ± s.e.m. of two independent experiments performed in triplicate for SKBR3 (n = 6) and duplicate for UACC812 (n = 4). Scale bar: 1.5 mm. The addictive effect from the EPZ and lapatinb was computed and shown in the figure. b Representative images (left) and quantification (right) of soft agar assay with SKBR3, or clonogenic assay with UACC812 treated with the solvent, EPZ (1 µM), trastuzumab (trast; 10 µg/ml), or the combination of both. Data are expressed as mean ± s.e.m. of two independent experiments performed in triplicate (n = 6). Scale bar: 1.5 mm. The addictive effect from the EPZ and trastuzumab was computed and shown in the figure. P values in a and b were determined with two-tailed Student’s t-test. c Representative western blot analysis (n = 2) with SKBR3 treated with the solvent, lapatinib (40 nM), EPZ (1 µM), or the combination of both. d Representative western blot analysis (n = 2) with SKBR3 treated with the solvent, trastuzuamb (10 µg/ml), EPZ (1 µM), or the combination of both. Effectors downstream of mTOR were highlighted in red in c and d. e Representative images (top) and quantification (bottom) of clonogenic assay with UACC812 transduced with shNC or shRNAs against PPP2R2B and treated with DMSO, lapatinib (lap; 20 nM), EPZ (1 µM), or the combination of both. Data are expressed as mean ± s.e.m. of two independent experiments performed in duplicates (n = 4). P values were determined with two-tailed Student’s t-test, and corrected with Bonferroni adjustment.