Fig. 3.

Validation of ERBB3 as an essential protein kinase in HNSCC cells. UMSCC8 (A, B), UMSCC25 (C), and HN6 cells (D) were transduced with lentiviruses encoding a control GFP shRNA or two ERBB3-targeted shRNAs (TRCN199364 and TRCN40108). After ∼10 days of culture under puromycin selection, the cells were submitted to RNA purification and reverse-transcription PCR (A) or the wells were fixed and stained with crystal violet and quantified by measuring the absorbance of the fixed cells at 590 nm (B–D). The data are the means and S.D. of duplicate wells from two independent experiments normalized to their GFP shRNA controls.