Overexpression of IRS-4 Correlates with Procaspase 3 Levels in Tumoural Tissue of Patients with Colorectal Cancer

Figure 3

(a) Immunoblot of IRS-4, IGF-1 signalling axis proteins and proliferation and apoptosis biomarkers in human colorectal carcinoma tissues (T) and matched adjacent normal colorectal tissues (N). The western blot was performed in normal (n=20) and tumoural (n=20) colorectal samples, results obtained from four representative patients are shown out of 20 subjects studied. (b) Nonspecific staining performed with Coomassie Blue (CB) of all samples was used as loading and quality control. CB staining of a representative patient is shown in normal (N) and tumoural (T) tissue. (c) The graph bar shows the mean ± SD of the densitometric analysis of the 66 kDa band and PCNA from normal (n=20) and tumoural (n=20) colorectal samples analysed by CB staining and western blot respectively. (d) Representative western blot of GSK-3, β-catenin and p53 fragments observed in normal (N) and tumoural (T) tissues. Results obtained from one representative patient are shown out of 20 subjects studied. (e) Immunoprecipitation using anti-BRK antibody and subsequent analysis of BRK, IRS-4 and phospho-IGF-1 receptor in samples from normal (N) and tumoural (T) tissues. The immunoprecipitation was performed three times for each of 6 selected patients’ samples. Results obtained from one representative patient are shown. Sample buffer was replaced for lysis extract in negative control (C-). H.C. = heavy chain of the immunoprecipitation antibody. N = MANC tissue. OD = optical density. A.U. = arbitrary units.