TLR2 and TLR4 polymorphisms influence mRNA and protein expression in colorectal cancer

Figure 1 Distribution of the median mRNA relative quantification values of genes TLR2 and TLR4. Using the Wilcoxon’s signed rank test, a statistically significant difference was found for TLR2 (^bP < 0.0001), but not for TLR4 (P = 0.452), when comparing the relative quantification (RQ) in colorectal cancer tissue (CRC) with adjacent normal tissue pools (NT). The reference genes ACTB and GAPDH were used as endogenous controls.

Figure 2 Toll-like receptor 2 and toll-like receptor 4 protein expression in intestinal mucosa (cytoplasm staining). Moderate expression of TLR2 in normal adjacent mucosa (NT), predominantly in epithelial cells (arrowhead) (A); compared with intense immunostaining in colorectal cancer (B); Low expression of TLR4 in normal adjacent mucosa, predominantly in the epithelium (arrowhead) (D); Moderate TLR4 immunostaining in the epithelial cells (arrowhead) of colorectal cancer (E); Harris’ Hematoxylin counterstain. Bar: 20 μm. Densitometry analyses (mean ± SE) (C and F); P < 0.001. All images are from the same patient. a.u.: Arbitrary unit; CRC: Colorectal cancer.

Figure 3 Toll-like receptor 2 (A) and toll-like receptor 4 (B) mRNA relative quantification, using tumor tissue samples from a wild-genotype colorectal cancer group as a calibrator, compared to those with at least one polymorphic allele. Using Wilcoxon’s signed rank test, a statistically significant difference was found for the gene expression of TLR2 (^aP = 0.037), but not for TLR4 (P = 1.000). The reference genes ACTB and GAPDH were used as endogenous controls. CRC: Colorectal cancer.

Figure 4 Densitometry values of immunohistochemistry analysis for toll-like receptor 2 and toll-like receptor 4 proteins, stratified according to polymorphic and wild genotypes. Carriers of the polymorphic genotype del/del for TLR2-196 to -174del polymorphism showed higher protein expression than those with homozygous wild genotype ins/ins (^aP = 0.03). No statistical difference was found for the values ​​of TLR4 protein. ins: Wild-type allele (insertion); del: Polymorphic allele (deletion).