Lipid Peroxidation and Antioxidant System in the Tumor and in the Blood of Patients with Nasopharyngeal Carcinoma

Abstract

Reactive oxygen species play a key role in cancer development by inducing and maintaining the oncogenic phenotypes of cancer cells. In this study, we examined lipid peroxidation and antioxidant enzymes activities in the blood and in the tumor of nasopharyngeal carcinoma patients. Plasma malondialdehyde, conjugated dienes, erythrocytes catalase, and superoxide dismutase activities have been measured in 30 untreated nasopharyngeal carcinoma patients and 30 controls on one hand. On the other hand, tumor malondialdehyde level, catalase, and superoxide dismutase activities have been measured in five nasopharyngeal carcinoma patients and compared with four controls. The lipid peroxidation was confirmed in the plasma by the high levels of malondialdehyde and conjugated dienes (p<0.001, respectively). Additionally, significantly higher concentrations of malondialdehyde were found in biopsies compared to the control group (p<0.001). In erythrocytes, superoxide dismutase activity was higher in patients than in controls (p<0.05), while it was unchanged in the tumor (p>0.05). Both erythrocytes and tumor catalase activities were significantly lower in patients than in controls (p<0.001, respectively). Statistical studies have shown a positive correlation between malondialdehyde level and IgA antibodies level against Epstein–Barr virus capsid antigen (p<0.05). In conclusion, we reported the presence of an oxidative stress in the blood and in the biopsies of nasopharyngeal carcinoma patients where Epstein–Barr virus seems to play a role.

Biomarkers of oxidative stress and smoking in cancer patients

“…[29][30][31][32] Our study found a reduction of erythrocyte membranes micro viscosity in protein-lipid regions (τ CII ) in cancer patients, which is consistent with data of authors who have reported analogous structural changes in cell membranes in patients with other cancer diseases. [33,34] The correlation of AO enzymatic activity and MDA level in erythrocytes was obtained with the stage of lung cancer of patients.…”

“…[1] Extensive epidemiological [26] and statistical date [27] clearly establish role of cigarette smoking in the genesis of lung cancer and head and neck cancer. It is known that neoplastic transformation is accompanied by changes in AO status, [28] in the extent of lipid oxidation, [29][30][31][32] micro viscosity of membranes and lipid composition [33,34] and an increase of DNA breaks number in both tumor tissue and leukocytes of blood. [35][36][37][38][39] The changes in these parameters indicate the involvement of oxidative stress in the process of malignancy.…”

Apoptosis, Free Radicals and Antioxidant Defense in Antitumor Therapy

“…Burlakova et al noted that the absence of a response these enzymes indicate a weakening of antioxidant enzymes system [118]. They found no change in the malondialdehyde (MDA) level, which is consistent with the previous work in patients with oral cancer [117,145,146,147]. In initial period its level is increased, but later it decreased [118].…”

Antioxidant enzymes and cancer

“…These types of mutation are reported in genes whose dysfunction is involved in the genesis of cancer [6] . ROS may also play a key role in cancer development by inducing and maintaining the oncogenic phenotypes of cancers [7] . The highly significant correlation between consumption of fats and oils and death rates from leukemia and malignant neoplasia of the breast, ovaries and rectum among persons over 55 years may be a reflection of greater lipid peroxidation [8] .…”