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. Author manuscript; available in PMC: 2016 Jan 1.
Published in final edited form as: Clin Cancer Res. 2014 Oct 27;21(1):157–165. doi: 10.1158/1078-0432.CCR-14-0610

Figure 2.

Figure 2

Low CBL mediates enhanced chemoresistance through EGFR autoactivation. A, MTT assay reveals that cell viability is enhanced with CBL knockdown in Panc-1 and L3.6pl cells treated with gemcitabine (Gem) or 5-fluorouracil (5-FU) at 24, 48 and 72 hours (P<0.05). Error bars ± SD. B, when treated with chemotherapy in serum-free conditions, immunoblot analysis of Panc-1 cells reveals that EGFR is autoactivated at it canonical autophosphorylation site (Y1068) with corresponding activation of downstream mediators ERK and AKT (columns 3 and 5 vs. 1). CBL knockdown further enhances autoactivation of EGFR at Y1068 as well as the docking site for CBL binding Y1045, (columns 3 vs. 4 and 5 vs. 6). Relative densitometry values using β-actin as a loading control are reported below each band. C, a human phosphoRTK immunoblot array of L3.6pl cells in gemcitabine (25nM) reveals that pEGFR is highly expressed and increased >2-fold with CBL knockdown.