Abstract
Background: Colorectal cancer (CRC) is the third most common type of cancer and leading cause of death worldwide. Major risk factors involved in the development of CRC are increased dietary sources, genetics, and increasing age. Purpose of the study was to find the role of different variables in the progression of CRC.
Methodology: 50 blood samples from CRC patients and 20 samples from control were collected. Serum was separated from the blood by centrifugation. This serum was assessed for several antioxidants like superoxide dismutase (SOD), glutathione, glutathione peroxidase, glutathione reductase, catalase, vitamin A, C, and E, and pro-oxidants such as malondialdehyde, advanced oxidation protein products (AOPPs), and AGEs according to their respective protocols. Matrix metalloproteinase-7 (MMP-7) and isoprostanes were assessed by ELISA kits.
Results: Lower levels of GSH (4.86 +/- 0.78 vs 9.65 +/- 1.13 mu g/dl), SOD (0.08 +/- 0.012 vs 0.46 +/- 0.017 mu g/dl), CAT (2.45 +/- 0.03 vs 4.22 +/- 0.19 mu mol/mol of protein), and GRx (5.16 +/- 0.06 vs 7.23 +/- 0.36 mu mol/ml) in the diseased group were recorded as compared with control. Higher levels of GPx (6.64 +/- 0.19 mmol/dl) were observed in the subjects in comparison with control group (1.58 +/- 0.30 mmol/dl). Highly significant decreased levels of vitamin A (0.81 +/- 0.07 vs 2.37 +/- 0.15 mg/ml), vitamin E (15.42 +/- 1.26 vs 25.96 +/- 2.19 mg/ml), and vitamin C (47.67 +/- 7.69 vs 80.37 +/- 10.21 mg/ml) were observed in the patients in contrast to control group. The reversal of antioxidants in later stages of CRC may be due to compensatory mechanisms in cancerous cells. The levels of MDA (nmol/ml) were also assessed, which shows significantly increased level in CRC patients as compared with control groups (3.67 +/- 0.19 vs 1.31 +/- 0.27). The levels of protein oxidation products [AGEs (2.74 +/- 0.16 vs 0.84 +/- 0.05 IU) and AOPPs (1.32 +/- 0.02 vs 0.82 +/- 0.07 ng/ml)] were significantly increased in subjects as compared with control. The levels of MMP-7 (64.75 +/- 3.03 vs 50.61 +/- 4.09 ng/ml) and isoprostanes (0.71 +/- 0.03 vs 0.16 +/- 0.02 ng/ml) were also analyzed. This shows that the levels of isoprostanes increased due to high lipid peroxidation mediate higher levels of MMP-7, which promotes development of CRC.
Conclusion: Following study suggested that elevated oxidative and inflammatory status along with lipid peroxidation and matrix metalloproteinases are the chief contributors in the progression of CRC.