A case-control study to detect the extent of DNA damage in oral lichen planus and oral lichenoid reactions using comet assay

Abstract

Aim:This study aims to quantify the extent of DNA damage in lymphocytes of patients with oral lichen planus (OLP) and oral lichenoid reactions (OLRs) using comet assay.Methodology:Lymphocytes from peripheral blood were subjected to alkaline comet assay. Comet length (CL), head diameter (HD), percentage of DNA in head, tail length (TL), percentage of DNA in tail, tail intensity, tail mean and tail moment were compared between study group (OLP and OLR) and control group using Student's t-test. Pearson's correlation coefficient was used to examine the linear association between the variables.Results:Significantly higher levels of DNA damage was present in study group as reflected by CL, HD and TL, tail intensity and tail moment with P = 0.0001; percentage of DNA in head and tail with P = 0.02 and tail mean with P = 0.012.Conclusion:This study brings out the fact that DNA damage measured by comet assay was greater in the study group when compared to the control group. As a reflection of uniqueness, this study crowns the scenario with respect to early detection and prevention of potentially malignant disorders and the process of malignant transformation.

Optimization of Alkaline Single Cell Gel Electropohoresis (Comet Assay) Protocol for Cells from Oral Cavity

“…In order to determine the Index of DNA damage (ID) for each treatment 10 slides, 50 comets scored in each slide, (500 comets) were selected from the assays 3 and 4 in each protocol. X 2 test was utilized and the Pearson correlation coefficient was applied when Damage Index in buccal and Vero cells, processed according to protocol 4 was compared [16]. Data obtained for nucleoids per field (x400), baseline DNA damage index, H 2 O 2 treated DNA damage index were analyzed by comparing the mean ± 0.95 confidence interval in each of the four protocols.…”

“…It is also the place where several diseases such as lichen or alterations like periodontal disease and leukoplakia are developed and may contribute to increased DNA damage. That DNA damage isn´t associated with exposure to environmental genotoxicity, but linked to local inflammation [16,21]. It is worth noting that in recent years oral mucosal cells have been utilized in assessing DNA damage in human populations due to the easiness in obtaining the sample [6]; but there are certain technical aspects that need to be addressed in order to increase the application of this variant of the assay [4,12,13,22,23].…”