Antioxidant defences and oxidative stress are related to development, progression and malignancy of colorectal cancer. However, their role in early stages of cancer remains unknown. More and more recent studies have revealed that non-tumour adjacent tissue is not a normal tissue. Thus, our aim was to analyse protein levels of MnSOD (Manganese Superoxide Dismutase), acMnSOD (Acetylated Manganese superoxide Dismutase), SIRT3 (Sirtuin 3), CuZnSOD (Cupper Zinc Superoxide Dismutase), CAT (Catalase), GPx (Glutathione Peroxidase), and GRd (Glutathione Reductase) both in tumour and non-tumour adjacent tissue from colorectal cancer patients by western blot. Non-tumour adjacent tissue seemed to have higher levels of antioxidant enzymes that detoxify hydrogen peroxide compared to tumour tissue. In contrast, tumour tissue had higher levels of MnSOD and acMnSOD. Furthermore, most of the proteins analysed showed significant differences between stage I and II in both non-tumour adjacent and tumour tissue. This could indicate that antioxidant enzymes, especially MnSOD, play a crucial role in early stages of colorectal cancer in both tissues, so they could be analysed as novel biomarkers to improve colorectal cancer diagnosis.

抗氧化防御和氧化应激与大肠癌的发生，发展和恶性相关。然而，它们在癌症早期阶段的作用仍然未知。越来越多的研究表明，非肿瘤邻近组织不是正常组织。因此，我们的目标是分析MnSOD（锰超氧化物歧化酶），acMnSOD（乙酰化锰超氧化物歧化酶），SIRT3（Sirtuin 3），CuZnSOD（铜锌超氧化物歧化酶），CAT（过氧化氢酶），GPx（谷胱甘肽过氧化物酶）， Western blot检测大肠癌患者肿瘤和非肿瘤邻近组织中的GrD和谷胱甘肽还原酶（Glutathione Reductionase）。与肿瘤组织相比，非肿瘤邻近组织似乎具有较高水平的抗氧化剂，可以使过氧化氢解毒。相反，肿瘤组织中的MnSOD和acMnSOD含量较高。此外，所分析的大多数蛋白质在非肿瘤邻近组织和肿瘤组织中均显示出I期和II期之间的显着差异。这可能表明抗氧化酶，特别是MnSOD，在两个组织的大肠癌早期阶段都起着至关重要的作用，因此它们可以作为新型生物标记物进行分析，以改善大肠癌的诊断。