Dokuz comet parametresine göre kadın ve erkek gruplarda sigara içiminin DNA hasarına etkisi

Ankara Üniversitesi Tıp Fakültesi Mecmuası 2012, 65 (1) DAHİLİ BİLİMLER/MEDICAL SCIENCES DOI: 10.1501/Tıpfak_000000805 Araştırma Makalesi / Research Article Effect of cigarette smoking on DNA damage according to nine comet assay parameters in female and male groups* Dokuz comet parametresine göre kadın ve erkek gruplarda sigara içiminin DNA hasarına etkisi Esma Söylemez, Zeliha Kayaaltı, Vugar Aliyev, Tülin Söylemezoğlu Ankara Üniversitesi Adli Bilimler Enstitüsü *This study is presented as poster in 47th Congress of the European Societies of Toxicology, 2011, Paris, France. Aim: Smoking poses a serious threat to public health. The aim of this study was to investigate the relationship between smoking and DNA damage in lymphocytes. A potential genotoxic effect of cigarette smoking was analyzed with the nine comet assay parameters including comet length (CL), comet intensity (CI), head length (HL), head intensity (HI), tail length (TL), tail intensity (TI), DNA tail (DNAt), tail moment (TM) and olive tail moment (OTM). For the first time in this study, smokers were grouped as female and male, and nine comet parameters were used. Material and Method: 120 volunteers (60 non-smokers, 60 smokers) were monitored in the way of DNA damage in blood lymphocytes. The levels of DNA damage was measured by BAB Bs Comet Assay system. Results: Highly significant associations were found between the non-smoker and smoker groups for CI, TL and OTM comet parameters (p<0.01). Smoker female group had higher CL, CI, HL, HI, TL, TI (p<0.01) and TM (p<0.05) with regard to DNA damages than the non-smoker female group. In contrast, only DNAt, and OTM comet parameters were statistically significantdifferences between the smoker male and non-smoker male groups (p<0.05). When the smoking index (SI) of all the blood samples from females were compared based on all studied comet parameters, statistically significant association was found except for TM. On the other hand, the blood samples taken from males were statistically significant in terms of CL, HL, HI, TI and OTM parameters (p<0.05). Conclusion: Consequently, it can be said that, smoking cause DNA damages and females are more sensitive to the effect of the smoking than males. Keywords: Comet assay, DNA damage, cigarette smoking. Amaç: Sigara kullanımı, halk sağlığı için ciddi bir tehdit olușturmaktadır. Çalıșmamızın amacı, sigara içimi ile lenfosit hücrelerinde DNA hasarı arasındaki ilișkiyi araștırmaktır. Sigaranın potansiyel genotoksik etkisi, “comet length” (CL), “comet intensity” (CI), “head length” (HL), “head intensity” (HI), “tail length” (TL), “tail intensity” (TI), “DNA tail” (DNAt), “tail moment” (TM) ve olive tail moment (OTM) gibi dokuz “comet assay” parametresi ile analiz edilmiștir. İlk kez bu çalıșmada sigara içenler kadın ve erkek olarak gruplara ayrılmıș ve dokuz comet parametresine göre değerlendirme yapılmıștır. Materyal ve Metod: 120 gönüllü birey (60 sigara içmeyen, 60 sigara içen) kan lenfosit hücrelerindeki DNA hasarları açısından izlenmiștir. DNA hasar dereceleri BAB Bs Comet Assay sistemi ile ölçülmüștür. Received: 06.10.2011 • Accepted: 23.02.2012 Corresponding Author Zeliha Kayaaltı Institute of Forensic Sciences, Ankara University, Ankara, Turkey Phone : 0 312 319 27 34 GSM : 0 505 366 38 48 Fax : 0 312 319 20 77 E-mail : Bulgular: Sigara içen ve içmeyen gruplar arasında CI, TL ve OTM comet parametreleri açısından yüksek derecede anlamlı ilișki bulundu (p<0.01). Sigara içen kadın grubunun DNA hasarı açısından CL, CI, HL, HI, TL, TI (p<0.01) ve TM (p<0.05) parametreleri sigara içmeyen kadın grubuna kıyasla daha yüksektir. Buna karșın, sigara içen ve içmeyen erkek grupları arasında sadece DNAt ve OTM parametreleri açısından istatistiksel anlamlı fark gözlenmiștir (p<0.05). Kadınlardan alınan tüm kan örneklerinin sigara indeksi (SI), tüm çalıșılan comet parametrelerine dayanarak karșılaștırıldığında, TM dıșındaki bütün parametreler ile istatistiksel olarak anlamlı ilișki bulunmuștur. Diğer taraftan, erkek grubundaki kan örneklerinde CL, HL, HI, TI ve OTM parametrelerinde istatistiksel anlamlılık gözlenmiștir (p<0.05). Sonuç: Netice olarak, sigaranın DNA hasarlarına sebep olduğu ve kadınların, sigaranın zararlı etkilerine karșı daha duyarlı olduğu söylenilebilir. Anahtar Sözcükler: Comet Assay, DNA hasarı, Sigara içimi. Ankara Üniversitesi Tıp Fakültesi Mecmuası 2012, 65 (1) Cigarette is a complex mixture of over 4800 chemical compounds, including a high concentration of oxidants, heavy metals, and carcinogens (1, 2). Smoking poses a serious threat to public health (3). Smoke inducedlung tumor has become one of the malignancies with the highest incidence and mortality worldwide (4). Extrapolating from the mortality due to smoking rates in 1985, and taking into account population growth, approximately 3-4 million deaths in developed countries from cigarette is anticipated in 2025 (5). The mechanism by which smoking induces damage is not known for all diseases. One mechanism believed to play a role is oxidative stress. Oxidative stress leads to cellular damage including DNA damage. The term oxidative stress is widely used in the literature, but not very well defined. Oxidative stress occurs when the amount of reactive oxygen species (ROS) generated in cells exceeds the capacity of normal detoxification systems (6,7). The importance of DNA oxidations is emphasized by their mutagenic potential, although there are multiple additional roles in aging and cancer, including, e.g., mitochondrial function, microsatellite instability and telomere shortening (8). Cigarette smoking has been investigated as a major risk factor for renal cell carcinoma (RCC) and squamous cell carcinoma of the head and neck (9). According to a meta-analysis conducted by Hunt and coworkers(10), ever smokers had an increased risk of RCC compared with lifetime never smokers (10). The alkaline single cell gel electrophoresis (SCGE) technique is highly effective in revealing the association between DNA damage and environmental, genetic, and acquired factors, providing further data on the possible applicability of this assay in genotoxic human surveillance in addition to established tests (11). SCGE, also known as 40 “comet assay”, is now a wellestablished genotoxicity test (12). The comet assay is based on the ability of negatively charged fragments of DNA to be drawn through an agarose gel in response to an electric field. The extent of DNA migration depends directly on the DNA damage present in the cells (13). In order to measure DNA single-strand breaks (14), alkaline-labile sites and DNA cross-linking in individual cells, this assay is used. It is applied to both in vivo and in vitro studies for many cells (15). The assay works on the principle that free radicals such as ROS cause breaks in the DNA (16,17). Using this assay we could potentially identify individuals with high levels of residual damage (18). To better characterize the suita (...truncated)