Figure 2
From: Oncogenic Role of the Ec Peptide of the IGF-1Ec Isoform in Prostate Cancer
The PEc effects are generated in an autocrine/paracrine manner. (A) Multiple Reaction Monitoring (MRM) protein analysis for the detection of the PEc-specific trypric products, (YQPPSTNK and GSTFEER) in the media of the mPC-3 and PC-3PEc. Sample 1: Tryptic products obtained from the media of mPC-3 cells. Sample 2: tryptic products of media obtained from PC-3PEc cells. Sample 3: tryptic products of synthetic PEc peptide (control). Significant amounts of both PEc tryptic products were detected into the PC-3PEc media. (B) Western analysis of ERK1/2 phosphorylation in PC-3PEc cells and in mPC-3 cells after the administration of exogenous synthetic PEc, incubated with increasing concentrations of rabbit anti-human PEc (anti-PEc) antibody (1:1,000; 1:500 and 1:50), for 1 h. Anti-IGF-1Ec antibody significantly decreased ERK1/2 phosphorylation in both cell types in a fashion that was directly proportional to the antibody concentration added in the culture media. In addition, nonimmunized rabbit serum did not affect the ERK1/2 phosphorylation in either system. In both cases, GAPDH was used as a control.