Comparison of hydrogen peroxide generation and the content of lipid peroxidation products in lung cancer tissue and pulmonary parenchyma

Abstract

Lipid peroxidation, as a well-known index of reactive oxygen species activity, not only in lung biochemistry, is an oxidative process associated with membrane lipid destruction. Also, the oxidative modification of nucleic acids by reactive oxygen species is of remarkable biological importance as it may contribute to malignant conversion, but its exact role in lung cancer biology is still not clear. Our study aimed to investigate the level of lipid peroxidation ex vivo in tumour tissue and lung parenchyma obtained from patients with lung cancer. Forty-two patients with lung cancer were enrolled into the study. During a surgical resection, tumour tissue and lung parenchyma were obtained and concentration of lipid peroxidation products, thiobarbituric acid-reactive substances and Schiff bases, and spontaneous generation of hydrogen peroxide, were measured. The concentration of thiobarbituric acid-reactive substances (P<0.001) in the tumour tissue was higher than that in lung parenchyma. In small cell lung cancer as well as in squamous cell carcinoma patients, a positive correlation between spontaneous generation of hydrogen peroxide in tumour tissue and clinical stage (r = 0.43; r = 0.46; respectively) was found. Our results prove enhanced lipid peroxidation in cancer tissue as compared with matched-lung parenchyma. In small cell lung cancer and squamous cell carcinoma patients, the high level of oxidative stress, expressed as a spontaneous generation of hydrogen peroxide in tumour tissue, was associated with clinical progression of tumour's stage.

Serum Malondialdehyde Levels and Superoxide Dismutase Activities in Pulmonary Tuberculosis and Lung Cancers

“…Enzyme has two forms, cytoplasmic (Cu,Zn-SOD) and mitochondrial (Mn-SOD) superoxide dismutase (23). Several investigators have reported that in lung cancerous tissue the activities of antioxidant enzymes were generally lower than in normal lung tissue (24). In our study, we observed that significant decrease in SOD activities in lung cancer patients leads to a net increase in the level of the superoxide free radical.…”

A New View of Carcinogenesis and an Alternative Approach to Cancer Therapy

“…•-and H 2 O 2 found in these cells (49)(50)(51)(52)(53), supports the idea that cancer cells have this alteration in the metabolism of O 2 . This alteration may play a crucial role in carcinogenesis by allowing the activation of glycolysis in the presence of O 2 and, therefore, the uncontrolled cell proliferation that characterizes cancer ( Figure 1B).…”

“…They showed, for instance, that a concentration of 50 μmol/L H 2 O 2 induced a higher percentage of cell death in Burkitt lymphoma cells than 250 μmol/L in normal lymphocytes and normal monocytes (108). In vitro and in vivo data indicate that tumor cells produce higher concentrations of H 2 O 2 than their normal counterparts (49)(50)(51)(52)(53). These data, and the fact that there is a threshold of H 2 O 2 above which cells cannot survive, may explain why specific concentrations of H 2 O 2 induce selective killing of cancer cells (36).…”

The role of Snail in prostate cancer

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