Fig. 6
CELx HSF Test signals in HER2+ and HER2- breast cancer cell lines. a HER2+ cell lines (n = 9) and HER2- cell lines (n = 10) were evaluated with the CELx HSF test as described in the Methods. The sum of NRG1b- and EGF-driven HER2 signals that can be inhibited by the HER2-specific mAb pertuzumab was approximated as response units for all cell lines and plotted. b Comparison of NRG1b-driven CELx signals in AU565, BT483, SKBr3 (HER2+ reference cell line), and MDA-MB231 (HER2- reference cell line) and sensitivities to HER2-targeted drugs (pertuzumab, lapatinib, and afatinib). c HER2 expression levels in HER2+ (n = 9) and HER2- cell lines (n = 10) were determined by fluorescence flow cytometry (mean fluorescence channel units, MFC) and plotted against the corresponding HER2 signal determined by CELx HSF test (response units) for each cell line. No correlation between the two parameters was observed (P = 0.204, R2 = 0.0929). Empty circles, HER2- cell lines; Filled circles, HER2+ cell lines. The locations of BT483, AU565, SKBr3 (HER2+ reference cell line) and MDA-MB231 (HER2- reference cell line) are indicated