Figure 2.

Consistent increase of argpyrimidine adducts in high stage tumors compared with low stage ones suggests a pro-tumor role for dicarbonyl stress. (A) Argpyrimidine adducts were examined in a series of 102 primary colorectal cancer patients samples grouped into four clinical stages (T1, T2, T3 and T4) and six normal colorectal tissues. One representative picture is shown for each stage analyzed (100× magnification); (B) Immunohistochemical quantification shows argpyrimidine staining evaluation divided into 4 groups (negative, weak, moderate and strong staining) based on the score values. Each dot represents one case and bars represent median. Statistical analysis has been performed using one-way ANOVA followed by Dunn’s Multiple Comparison Test and * p < 0.05, ** p < 0.01, *** p < 0.001. In the right panel, the percentage of negative, weak, moderate and strong argpyrimidine staining is shown for normal tissue and stage 1 to stage 4 tumors; (C) An IHC using an antibody against MG-H1 adducts has been performed on 12 CRC samples. IHC staining is shown for representative negative, moderate and strong staining (100× magnification). In accordance with argpyrimidine immunostaining, more MG-H1 adducts have been detected in the highest stage lesions; (D) Argpyrimidine and MG-H1 IHC detection showed a significant positive correlation (R² = 0.74, p = 0.0003, Spearman rank correlation test).