Figure 5
From: Peptidomimetics designed to bind to RAS effector domain are promising cancer therapeutic compounds
P1.3 reduces PI3K and c-RAF1 signalling and interaction with KRAS; and decreases pancreatic tumour cells but not normal cells viability. (a) hTERT-RPE starved cells were incubated with 25 µM of the indicated peptidomimetics for 2 h and the levels of activation of the RAF/MEK/ERK and PI3K/AKT pathways after EGF stimulation for 10 min were studied by Western blot. Specific antibodies against the active phosphorylated and total proteins were used. GAP120 was utilized as a loading control. (b) Co-immunoprecipitation of HA-KRASG12V with C-RAF or with PI3K was analysed in starved HeLa cells expressing HA-KRASG12V after being incubated with 100 µM of P1.3 for 2 h, and EGF-stimulated for 10 min. IP was performed with anti-HA antibodies and Western blot of the bound and input fractions with anti-p110αPI3K and anti-C-RAF. (c) Effect of P1.3 on the cell viability of six pancreatic adenocarcinoma human cell lines (all harbouring oncogenic KRAS mutations) and of a non-transformed cell line (hTERT-RPE). Cells were treated with P1.3 in a dose range from 0 to 25 µM and incubated for 24 h, when cell viability was determined by MTS assay. Experiments (a) and (c) were repeated at least three times, and (b) once. Differences were assessed using one-way ANOVA and Tukey Multiple Comparisons Test and considered significant when p ≤ 0.05.
