Evaluation of DNA Damage in the Buccal Cells of patients with Oral Submucous Fibrosis using Comet Assay

BACKGROUND: Oral submucous fibrosis (OSF) is one of the potentially malignant disorders with a high chance of developing into oral squamous cell carcinoma. Several factors like as chili consumption, genetic susceptibility, autoimmunity, nutritional deficiency states and collagen disorders have also been suggested to be involved in the pathogenesis of this condition. However areca nut quid has been accepted today as a chief etiological factor for oral submucous fibrosis. The various components of areca nut have shown to have carcinogenic potential. Since the buccal epithelial cells are continuously exposed to the genotoxic agents in areca nut, tobacco, reactive oxygen species and nitrosamines, they are prone to undergo DNA damage which can lead to the development of oral squamous cell carcinoma. Hence detection of these subclinical DNA damages are of paramount importance to prevent the malignant transformation of oral submucous fibrosis. Comet assay is a non-invasive technique that can serve as a powerful tool in the detection of these genetic level DNA damages. AIM OF THE STUDY: To evaluate the DNA damage in the buccal cells of patients with oral submucous fibrosis using comet assay. MATERIALS AND METHODS: The study subjects were recruited from the patients attending Vivekanandha Dental College for Women. Patients who were clinically diagnosed with oral submucous fibrosis under standard diagnostic criteria were selected. The control group included age matched subjects without habits, other oral lesions and systemic illness. The study sample size included 60 subjects out of which 30 belonged to the OSF group and 30 to the control group. After obtaining their informed consent the cytological smears were collected from the individuals and subjected to the comet assay procedure to assess the DNA damage by measuring the tail length of the comets. RESULTS: The high average tail length of 2.25 μm was found in patients with OSF when compared to the control group who had an average tail length of 1.35 μm. There was a statistically significant increase in tail length with the duration of habit in the OSF patients. On comparing the tail length between males and females, a statistically significant increase in tail length was seen in males in the control group. CONCLUSION: Comet assay can be used as powerful screening tools to create awareness among the public about the deleterious effects of harmful habits on the oral mucosa and thereby aid in the prevention of oral cancer