Analysis of Oxidative DNA Damage / Oxidative Stress Markers in Patients with Ovarian Cancer

Abstract

Although the role of oxidative stress in the process of carcinogenesis seems well known, the quantitative correlation between oxidative DNA damage and the degree of histological malignancy of a neoplasm has not yet been determined. In the present study we attempted to show the possible correlations by looking at the amounts of the basic oxidative stress markers 8-oxoGua (8-oxo-7.8-dihydroguanine) and 8-oxodG (8-oxo-7.8-dihydro-2’-deoxyguanosine) excreted in the urine of patients. All the previously mentioned modifications were analyzed using techniques involving high performance liquid chromatography/electrochemical detection (HPLC/EC) or HPLC/gas chromatography and mass spectroscopy (GC-MS). All patients (n=46) suffered from ovarian cancer and were divided into three groups: G1, G2, and G3, according to the degree of histological malignancy of the neoplasm. In the female patients whose neoplasms showed higher degrees of histological malignancy significantly higher median values of 8-oxoGua and 8-oxodG were found to be excreted in their urine. In the subgroup of patients with G3 feature, both these markers of oxidative stress were almost twice as high as in the subgroup with G1 feature. The results suggest that the oxidative stress in ovarian cancer patients as demonstrated by increased amounts of these modifications in urine may be typical not only for the affected tissue, but also for other tissues and even the whole organism. It is also possible that the accumulation of oxidative stress is proportional to the degree of histological malignancy and depends on histological diagnosis.