Enhanced lipid peroxidation in cancer tissue homogenates in non-small cell lung cancer

The oxidative modification of nucleic acids by reactive oxygen species may lead to malignant conversion, but its exact role in lung cancer biology is still not clear. Lipid peroxidation, a well-known index of free radicals activity, is a process of oxidative polyunsaturated acids destruction. Our study was aimed to investigate the level of lipid peroxidation ex vivo in tumor tissue and lung parenchyma obtained from patients with non-small cell lung cancer. Thirty-two patients with lung cancer (including 19 with squamous cell lung cancer) were enrolled in the study. During a surgical resection, tumor tissue and lung parenchyma were obtained and the concentration of lipid peroxidation products, i.e. conjugated dienes and lipid hydroperoxides, measured. In the whole group of patients the concentrations of conjugated dienes and lipid hydroperoxides in the tumor tissue were higher than those in lung parenchyma (1.008 +/- 0.503 A233 nm vs. 0.717 +/- 0.283 A233 nm; p < 0.05 and 0.109 +/- 0.062 A532 nm vs. 0.102 +/- 0.087 A532 nm; p < 0.05, respectively). Similar results were obtained in squamous cell carcinoma patients (0.975 +/- 0.348 A233 nm vs. 0.708 +/- 0.300 A233 nm; p > 0.02 and 0.094 +/- 0.029 A532 nm vs. 0.080 +/- 0.071 A532 nm; p < 0.05, respectively). In both groups of patients, a positive correlation between concentration of conjugated dienes in tumor tissue and clinical stage (R = 0.45; R = 0.52; p < 0.05, respectively) was found. Our results confirm the enhanced lipid peroxidation in cancer tissue as compared with matched lung parenchyma. Additionally, a higher level of oxidative stress, expressed as the concentration of conjugated dienes in tumor tissue, was associated with clinical progression of the tumor.