The level of oxidative stress and the expression of genes involved in DNA-damage signaling pathways in depressive patients with colorectal carcinoma.

OBJECTIVES: This study investigated the connection among the oxidative stress, depression and expression of specific genes involved in DNA-damage signaling pathways in patients with colorectal carcinoma (CRC).

METHODS: A unique Dukes'C subset of patients with newly diagnosed colorectal adenocarcinoma were assessed using the Hamilton Depression Rating Scale (HAMD), Zung Self-rating Depression Scale (SDS), Zung Self-rating Anxiety Scale (SAS), Symptom Checklist 90 (SCL-90) and other multiple-item questionnaires. Oxidative-stress-related parameters in sera and the expression of genes were monitored during a pretreatment period.

RESULTS: Eighty-two eligibility cases were divided into 2 groups based on an HAMD score cutoff of 20: the mean score was 28.29 in Group A (depression, n=52) and 16.50 in Group B (nondepression, n=30). The serum total antioxidant capacity, catalase, and superoxide dismutase concentrations were lower in Group A, whereas those of nitric oxide and malondialdehyde were higher in Group A. Importantly, the 8-hydroxy-deoxyguanosine level was higher in Group A than in Group B (P<.05). Microarray analysis revealed that the expressions of p34, PA26, and ABL were higher in Group A, whereas those of HRAD51, CR6, and XRCC3 were higher in Group B.

CONCLUSION: Oxidative stress is capable of causing neuronal toxicity via lipid peroxidation, DNA damage, and abnormalities of gene expression, and therefore is a possible pathogenic mechanism underlying depression in patients with CRC.