Figure 1.
Immunofluorescence staining for phosphorylated RB is increased in colon biopsies from CD patients.
A. RB phosphorylation was detected in colon biopsies from control (non inflamed; n = 5), CD (n = 7) and UC patients (n = 6) by immunofluorescence staining using phosphorylated RB Ser807/811 and phosphorylated RB Thr821/826 antibodies. Nuclei were stained with 4′,6-diamidino-2-phenylindole (DAPI). Scale bar = 50 µm. B. Histogram showing RB fluorescence staining intensity in Ser807/811 (white bars) and Thr821/826 (black bars) residues. *p<0.05 when compared with percentage of phosphorylated RB Ser807/811-positive cells in UC samples and ##p<0.01 when compared with percentage of phosphorylated RB Thr821/826 -positive cells in UC samples.
Figure 2.
RB phosphorylation is increased in colonic epithelial cells from CD patients.
A. RB phosphorylation was detected in colon biopsies from control (non inflamed), CD and UC patients by immunohistochemistry using phosphorylated RB Ser807/811antibody. Slides were counterstained with methyl green. Scale bar = 50 µm. Arrowheads point to phosphorylated RB-positive cells. B. Histogram shows the percentage of phosphorylated RB-positive cells in control (n = 5), CD (n = 15) and UC (n = 13) samples. *p<0.0001 when compared with phospho-RB Ser807/811 staining in control samples. Scale bar = 50 µm.
Figure 3.
β-catenin is overexpressed in colonic samples from UC patients.
A. Colonic biopsies from control (non inflamed), CD and UC patients were stained by immunohistochemistry using anti-β-catenin antibody. Slides were counterstained with methyl green. Scale bar = 50 µm. B. Representative pictures of β-catenin staining scores (0 to 3). C. Graph shows the mean scores of β-catenin expression intensity in control (n = 5), CD (n = 14) and UC (n = 14) samples. *p = 0.019 when compared with β-catenin expression scores in CD samples.
Figure 4.
Immunoblotting detection of phospho-Rb and β-catenin in samples from control, CD and UC samples.
A. Representative images of imunnoblots from control (CTL, n = 4), CD (n = 4) and UC (n = 4) samples, detecting β-catenin expression and RB phosphorylation at ser 807/811 residues (phospho-RB ser807/811). α-tubulin was used as loading control. B. Histogram showing the quantification of RB phosphorylation at Ser807/811 residues in control (CTL), CD and UC samples by band densitometry. C. Histogram showing the quantification of β-catenin expression in control (CTL), CD and UC samples by band densitometry. ***p = 0.005 when compared with UC.
Figure 5.
Scatter-plot showing the correlation between phospho-RB and b-catenin among patients with CD and UC.
ROC curves determined thresholds for establishing positive test values. Phospho-RB is expressed as percentages, while β-catenin is expressed as intensity scores.
Table 1.
Diagnostic capability of phospho-RB and β-catenin immunhistochemical tests in differentiating Crohn's disease from ulcerative colitis.
Figure 6.
Phospho-RB and β-catenin staining pattern helps the differential diagnose of IBDU cases.
A. Low phospho-RB ser807/811and high β-catenin staining in a 50-year old woman patient lately diagnosed with UC (Patient A). B. High phospho-RB ser807/811and low β-catenin staining in a 28-year old woman lately diagnosed with CD (Patient B). Slides were counterstained with methyl green. Scale bar = 50 µm.