Content of 8-Hydroxy-2-Deoxyguanosine in Steroid Receptor-Positive and Receptor-Negative Breast Cancer Cells

The content of DNA damage marker 8-hydroxy-2-deoxyguanosine in 16 receptor-negative and 18 receptor-positive human breast neoplasms was measured by immunohistochemical methods. Positive staining was revealed in 81.3±9.8 and 50.0±11.7% samples of groups 1 and 2, respectively. The effect of arylhydrocarbon receptor agonist β-naphthoflavone on the content of 8-hydroxy-2-deoxyguanosine and number of estrogen and progesterone receptors was evaluated in MCF-7 breast cancer cells. The degree of genotoxic damage significantly increased 1 h after combined treatment with estradiol and β-naphthoflavone (in contrast to individual treatment) and remained practically unchanged in the follow-up period. According to the estrogen effect-switching phenomenon, genotoxic damage can contribute to the development of R− breast cancer. Key Wordsbreast cancer-MCF-7 cell line-estrogen and progesterone receptors-8-hydroxy-2-deoxyguanosine __________ Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 140, No. 7, pp. 100–103, July, 2005