Combination of neutrophil gelatinase-associated lipocalin and matrix metalloproteinase-9 are biomarkers for the detection of colon tubular adenocarcinoma

Figure 1 The relative expression of neutrophil gelatinase-associated lipocalin was consistent with the content of pro-gastrin-releasing peptide in serum. A: The relative gene expression of neutrophil gelatinase-associated lipocalin in serum in normal and six samples of tubular adenocarcinoma of the colon (P1 to P6); B: The content of pro-gastrin-releasing peptide (pg/mL) in serum. Three independent experiments were carried out and analyzed. Data are expressed as mean values ± SE, ^bP < 0.01, two-tailed Student’s t-tests. NGAL: Neutrophil gelatinase-associated lipocalin; pro-GRP: Pro-gastrin-releasing peptide.

Figure 2 Expression of neutrophil gelatinase-associated lipocalin and matrix metalloproteinase-9 in tubular adenocarcinoma of the colon. A and B: The relative neutrophil gelatinase-associated lipocalin (NGAL) (A) and matrix metalloproteinase-9 (MMP-9) (B) gene expression in serum samples from normal tissues (n = 10) and patient tissues with different stages of tubular adenocarcinoma of the colon (From I to III) (n = 30); C and D: Western blotting analysis of the expression of NGAL (C) and MMP-9 (D) at the protein level. Three independent experiments were carried and analyzed. Data are expressed as mean values ± SE, ^bP < 0.01, two-tailed Student’s t-tests. NGAL: Neutrophil gelatinase-associated lipocalin; MMP-9: Matrix metalloproteinase-9.

Figure 3 Neutrophil gelatinase-associated lipocalin and matrix metalloproteinase-9 immunoexpression in tubular adenocarcinoma of the colon (original magnification, 200 ×). Upper panel: Neutrophil gelatinase-associated lipocalin staining; Lower panel: Matrix metalloproteinase-9 staining. A and E: Control; B and F: Polyps; C and G: Mild tubular adenocarcinoma; D and H: Severe tubular adenocarcinoma.

Figure 4 The combination of neutrophil gelatinase-associated lipocalin and matrix metalloproteinase-9 improved the accuracy of the diagnosis of tubular adenocarcinoma of the colon. Data are expressed as mean values ± SE, ^bP < 0.01, two-tailed Student’s t-tests. NGAL: Neutrophil gelatinase-associated lipocalin; pro-GRP: Pro-gastrin-releasing peptide; MMP-9: Matrix metalloproteinase-9.

Figure 5 Content of pro-gastrin-releasing peptide (pg/mL) in serum samples from normal tissues (n = 10) and from patient tissues with different stages of tubular adenocarcinoma of the colon (stage I-III) (n = 10). Three independent experiments were carried out and analyzed. Data are expressed as mean values ± SE, ^bP < 0.01, two-tailed Student’s t-tests. pro-GRP: Pro-gastrin-releasing peptide.