Correlation between oxidative stress and trace elements in blood of patients with cancer

Jiafu FENG; Shaolin LI

ABSTRACT

BACKGROUND:

The occurrence and development of tumor may result from the reaction of a series of factors. Up to now, earlier detection, monitoring treatment, and prognosis assessment for tumor are very difficult. It can provide the theoretical foundation of rehabilitation and survival for cancer patients to study the mechanisms of occurrence and development of tumors, or investigate the changes of blood level and tissue distribution.

OBJECTIVE:

To investigate the changes of levels of some trace elements and serous prooxidant-antioxidant system of cancer patients.

DESIGN:

A controlled observation trial

SETTING:

Department of Laboratory Medicine, Mianyang CentralHospital.

PARTICIPANTS:

From September 1999 to December 2000,111 cancer patients were selected from the Third People's Hospital of Zigong, Yibin First People's Hospital of Sichuan Province, and Longchang County people's Hospital of Neijiang City, Sichuan Province.Of them, 21 cases were of liver cancer, 16 of gastric carcinoma, 15 of colorectal cancer, 11 of breast cancer, 13 of lung cancer, 13 of esophageal cancer, 7 of brain cancer and 15 of other cancers. At the same time; 36 control subjects were recruited from those who came to the hospital for health examination.

METHODS:

Blood samples of subjects after overnight fasting were pre pared by collecting venous blood in 5-mL Vacutainer tubes (Becton Dickinson, American). After 2-3 hours, the blood samples were centrifuged at 3 000 r/min for 15 minutes. 2.0 to 3.0 mL of serum was separated. The sera were stored in the refrigerator until analysis. Serum glutathione(GSH)level was determined by dithiobis-2-nitrobenzoic acid colorimetry. Xanthine oxidase (XOD) concentration was determined with xanthine-nitrotetrazole colorimetry. Glutahione oxidase (GSHPx) activity was determined with dinitrobenzoic acid colorimetry. Malondialdehyde(MDA) concentration in serum was measured with thiobarbituric acid reaction. Vitamin C (Vit C),vitamin E(Vit E) and total antioxidant power(TAOP) levels were measured with phenanthroline colorimetry. Albumin concentration was determined with bromcresol purple. Serum transferrin (Trf) and ceruloplasmin (CER)concentrations were determined with immunonephelometry. The concentrations of Cu, Zn, Fe, and Se were measured with flame atomic absorption spectroscopy.MAIN OUTCOME

MEASURES:

MDA (as lipid peroxidation marker),trace elements copper, zinc, iron, and selenium and their transport proteins (albumin, transferrin and ceruloplasmin); antioxidation status markers the concentrations of XOD, GSH, GSHPx, vitamin C, and vitamin E, and total antioxidant power levels.

RESULTS:

It was shown that lipid peroxidation ( measured as MDA)was significantly higher in cancer patients than in healthy controls [(5.21±1.05) nmol/L vs (4.04±0.68) nmol/L,P ＜ 0.001], and the TAOP level was significantly decreased in cancer patients than in the health controls[(4.34±0.980) U/L vs (5.87±0.93) U/L,P ＜ 0.001]. There were not obvious changes of antioxidation components (XOD, GSH, GSHPx, vitamin C,and vitamin E). Serum albumin concentration was found to be significantly lower in the cancer patients than in the health controls [(34.19±6.94)g/L vs (42.34±4.89) g/L ,P ＜ 0.001], and serum ceruloplasmin concentration was found to be significantly higher in the cancer patients than in the health controls [(0.371 ±0.031) g/L vs (0.346±0.026) g/L,P ＜ 0.05] butserum transferrin concentration remained unaltered (P ＞ 0.05). As com pared with the healthy controls, serum copper level was significantly increased[(19.27±4.74) μmol/L vs (14.29±2.71) μmol/L, P ＜ 0.001], serum selenium levels was significantly decreased[(1.175±0.333 0 μmol/L vs (1.413±0.446) μmol/L,P ＜ 0.001)]. However, the concentrations of zinc and iron remained unchanged. Correlation was observed between copper and MDA levels (r=0.281, P=0.003) in the cancer patients but not in the healthy controls. Moreover, a correlation was also observed between serum iron and MDA levels in the patients with liver cancer (r=0.680,P=0.001).

CONCLUSION:

The presence of an association between oxidative stress and some trace elements was found in cancer patients; however, the results are possibly inconsisteut because of different cancer types, cancer grades,or other characteristics of the patients engaged in the test.