Department of Genetics, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Bloco G. Av. Bandeirantes, Ribeirão Preto, SP 3900, Brazil.
Clin Exp Med. 2010 Jun;10(2):87-92. doi: 10.1007/s10238-009-0079-4. Epub 2009 Nov 10.
Breast cancer is the second most frequent type of cancer worldwide and is the most common malignant disease among women. Risk factors for breast cancer include early menarche, late menopause, hormonal therapies, exposure to environmental pollutants, smoking and alcohol use. However, increased or prolonged exposure to estrogen is the most important risk factor. It has been suggested that accumulation of DNA damage may contribute to breast carcinogenesis. Epidemiological studies suggest that cytogenetic biomarkers such as micronuclei in peripheral blood lymphocytes may predict cancer risk because they indicate genomic instability in target tissues. The objective of the present study was to evaluate the frequencies of micronuclei and the extent of DNA damage detected by comet assay in peripheral blood lymphocytes of untreated breast cancer patients and healthy women. The study was conducted using peripheral blood lymphocytes from 45 women diagnosed for Ductal "in situ" or invasive breast carcinoma and 85 healthy control women. Micronuclei and comet assays were performed to detect spontaneous DNA damage. The results showed that micronuclei frequencies and tail intensity, detected by comet assay, were significantly higher in the breast cancer group than in controls. The levels of DNA damage were similar in smokers and non-smokers, and aging did not influence the frequencies of micronuclei or tail intensity values observed in either group. In conclusion, the present work demonstrates higher levels of DNA damage in untreated breast cancer patients than in healthy women.
乳腺癌是全球第二常见的癌症类型，也是女性中最常见的恶性疾病。乳腺癌的危险因素包括初潮早、绝经晚、激素治疗、暴露于环境污染物、吸烟和饮酒。然而，雌激素的增加或延长暴露是最重要的危险因素。有人认为，DNA 损伤的积累可能导致乳腺癌的发生。流行病学研究表明，外周血淋巴细胞中的微核等细胞遗传学生物标志物可能预测癌症风险，因为它们表明靶组织中的基因组不稳定性。本研究旨在评估未治疗的乳腺癌患者和健康女性外周血淋巴细胞中微核的频率和彗星试验检测到的 DNA 损伤程度。该研究使用了 45 名诊断为导管原位或浸润性乳腺癌的女性和 85 名健康对照女性的外周血淋巴细胞。进行了微核和彗星试验以检测自发 DNA 损伤。结果表明，乳腺癌组的微核频率和彗星试验检测到的尾部强度明显高于对照组。吸烟和不吸烟组的 DNA 损伤水平相似，年龄增长对两组观察到的微核频率或尾部强度值均无影响。总之，本研究表明，未经治疗的乳腺癌患者的 DNA 损伤水平高于健康女性。
