Figure 1.
Cell surface expression of ERBB. A: Nine neuroblastoma cell lines were incubated with anti-ERBB antibody either directly conjugated to PE (EGFR) or then incubated with a secondary PE conjugated antibody (HER-3 and HER-4). Positive controls were A431 (EGFR) and T47D (HER-3 and HER-4). Filled histograms represent the isotype control and unfilled histograms represent ERBB-PE expression. B: RNA from cell lines SK-N-AS, SK-N-SH, IMR32 and CHP134 was reverse-transcribed and assessed by Q-PCR for expression of each of the Her-4 juxtramembranous isoforms. Histograms represent copies of each of the four isoforms (JMa, JMb, JMc and JMd) per million copies of GAPDH. Triplicate samples were analyzed; error bars represent standard deviation. Cleavable isoforms of Her-4 (JMa and JMd) were much more abundant than non-cleavable isoforms (JMb and JMc) for all lines tested.