Oxidative damage and transforming growth factor β1 expression in pretumoral and tumoral lesions of human intestine

The aim of this study was to evaluate a possible relationship between oxidative stress and transforming growth factor β1 (TGFβ1) expression in human colon adenocarcinoma. Crohn's disease, an inflammatory pathology of the intestine often regarded to as precancerous, was also examined. Indices of impaired redox balance were monitored in blood and in bioptic samples from 10 adult patients with adenocarcinoma of the colon and from five patients with Crohn's disease. On tissue samples TGFβ1 mRNA expression was also determined. Ten healthy adults provided normal reference values for plasma indices of oxidative stress, and normal tissue distant from the lesions was used for comparative analysis. Fluorescent adducts with plasma proteins of malonaldehyde (MDA) and 4-hydroxynonenal (HNE) were significantly lower than controls in the plasma from cancer patients and significantly higher in the plasma from Crohn's patients. In adenocarcinoma biopsies, susceptibility to lipid peroxidation processes and TGFβ1 expression were below the relative control; in Crohn's disease, lipid peroxidation and cytokine expression were both above the relative control. The findings obtained suggest the existence of an association between oxidative damage and fibrogenic cytokine expression in the human intestine. Further studies are needed to conclusively prove the correlation between the two events.