Abstract
Background: Establishment of early prediction of oral cancer is important. We evaluated both lymphocyte DNA damage by Single cell gel electrophoresis (SCGE) and non-invasive urinary 8-hydroxy-2-deoxyguanosine (8-OHdG) biomarker of oxidative stress (OS). OS and poorly maintained antioxidant defense system may leads to increased intracellular reactive oxygen species (ROS) that can control basic cellular functions, such as proliferation and apoptosis which leads to the development of cancer.
Objectives: To evaluate total antioxidant status (TAS) and the extent of oxidative stress (OS) by measuring DNA damage in oral leukoplakia and oral squamous cell carcinoma (OSCC) in comparison to normal healthy individuals.
Methods: A total of 95 subjects aged 30 – 70 were included for the study. Of these 30 were healthy controls, 30 patients with oral leukoplakia and 35 clinically and histologically diagnosed patients with OSCC. Blood samples were evaluated for malondialdehyde (MDA), comet assay and antioxidants. Random urine specimens were collected for 8-OHdG estimation.
Results: Significant increase in DNA damage with decreased antioxidants status was observed in oral leukoplakia compared to OSCC patients and controls. TAS and lymphocyte DNA damage showed a strong negative correlation and comet assay and urinary 8-OHdG showed a strong positive correlation among three groups.
Conclusion: Oral cancer associated with OS causes genotoxic susceptibility in cancer. Lack of DNA repair mechanisms causes extensive DNA damage in oral leukoplakia patients, suggesting that OS is important in the pathogenesis of oral cancer.
Keywords: Antioxidants, comet assay, DNA damage, lymphocyte, oral cancer and oxidative stress.
References
- Parkin DM, Laara E, Muir CS., Estimates of the worldwide frequency of sixteen major cancers in 1980. Int J Cancer, 1988; 41(2):184-97.
- Batsakis JG. Tumors of the head and neck-clinical and Pathological considerations; 2nd, Baltimore: Williams and Wilkins company, 1979.
- Liu RH, Hotchriss JH., Potential genotoxicity of chronically elevated nitric oxide: a review. Mutat Res, 1995; 339: 73-89.
- Proia NK, Paszkiewicz GM, Nasca MA, Franke GE, Pauly JL., Smoking and smokeless tobacco-associated human buccal cell mutations and their association with oral cancer: A review. Cancer Epidemiol Biomarkers Prev, 2006; 15: 1061-77.
- Ohkawa H, Ohishi N, Yagi K., Assay of lipid peroxide in animal tissue by thiobarbituric acid reaction. Anal Biochem, 1979; 95: 351.
- Singh PN, McCoy MT, Tice RR, Schneider EL., A simple technique for quantitation of low levels of DNA damage in individual cells. Exp Cell Res, 1988; 175(1): 184–91.
- Burlinson B, Tice RR, Speit G, Agurell E, Brendler-Schwaab SY, Collins AR. et al., Fourth International Workshop on Genotoxicity testing: resulting of the in vivo Comet assay workgroup. Mutat Res, 2007; 627: 31-5.
- Bonde P, Gao D, Chen L., Selective decrease in the DNA base excision repair pathway in squamous cell cancer of the esophagus. J Thorac Cardiovasc Surg, 2007; 133: 74-81.
- Warnakulasuriya S., Significant oral cancer risk associated with low socioeconomic status. Evid Based Dent, 2009; 10(1): 4-5.
- Mukherjee S, Ray JG, chaudhuri K., Evaluation of DNA damage in oral precancerous and squamous cell carcinoma patients by single cell gel electrophoresis. Indian J Dent Res, 2011; 22(5): 735-6.
- Ribeiro DA., The single cell gel (comet) assay as a promising tool for the detection of DNA damage induced by compounds used in dental practice: the oral cancer risk assessment. Crit Rev Oncog, 2008; 14(2):165.
- Anuradha U, Malini J, Rajeswari N, Neena Desai, Jain S, Balakrishna N, et al., Risk assessment in cervical dysplasia patients by single cell gel electrophoresis assay: a study of DNA damage and repair. Mutation Research, 1998; 412:195-205.
- Patricia A. Escobar, Martyn T. Smith, Ananth Vasishta, Alan E. Hubbard and Luoping Zhang., Leukemia-specific chromosome damage detected by comet with fluorescence in situ hybridization (comet-FISH). Mutagenesis, 2007; 22(5): 321-7.
- Kristin L.Lockett, M.Craig Hall, Peter E.Clark, Shu-Chun Chuang, Brittany Robinson, Hui-Yi Lin, et al., DNA damage levels in prostate cancer cases and control. Carcinogenesis, 2006; 27(6): 1187-93.
- Chiou CC, Chang PY, Chan EC, Wu TL, Tsao KC, Wu JT., Urinary 8-hydroxy deoxy guanosine and its analogs as DNA marker of oxidative stress: development of an ELISA and measurement in both bladder & prostate cancers. Clin Chim Acta, 2003; 334: 87-94.
- Brown RK, McBurney A, Lunec J, Kelly FJ., Oxidative damage to DNA in patients with cystic fibrosis. Free Radic Biol Med, 1995; 18: 801-6.
- Tsuboi H, Kouda K, Takeuchi H, Takigawa M, Masamoto Y, Takeuchi M, Ochi H., 8-hydroxy guanosine in urine as an index of oxidative damage to DNA in the evaluation of atopic dermatitis. Br J Dermatol, 1998; 138: 1033-5.
- Rall LC, Roubenoff R, Meydani SN, Han SN, Meyani MJ., Urinary 8-hydroxy-2’-deoxy guanosine (8-OHdG) as a marker of oxidative stress in rheumatoid arthritis and aging: effect of progressive resistance training. Nutr Biochem, 2000; 11: 581-4.
Corresponding Author
Dr. Subash. P
Associate Professor, Department of Biochemistry, KMCT Medical College, Kerala University of Health Sciences, Manassery 673602, Kozhikode, Kerala-India
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.