Evaluating the accuracy of microRNA27b and microRNA137 as biomarkers of activity and potential malignant transformation in oral lichen planus patients.

Oral lichen planus (OLP) is a chronic inflammatory mucocutaneous disease with a potential malignant transformation, characterized by cytotoxic T cells against basal epithelial cells. MicroRNAs (MiRNAs) are short non-coding RNA that plays critical role in gene expression at post-transcriptional levels. Much evidence showed that miRNAs play an important role in regulating immune response and cancer development. The purpose of the present study was to compare the expression of miRNA 27b and miRNA 137 in tissues and saliva between OLP patients and controls by using RT-qPCR and to evaluate their use as biomarkers of disease activity and potential malignant transformation. Our results showed down expression of miRNA 27b and miRNA 137 in tissue and saliva of OLP patients compared to controls; among OLP subgroups, erosive-type miRNA 137 revealed the lowest level in tissue and saliva. In conclusion, alteration of miRNA 27b and miRNA 137 gene expression signify their use as biomarkers for diseases activity and tendency of malignant transformation, and down expression of miRNA 137 especially in erosive-type favors the use of saliva sample as a noninvasive method for monitoring a potential malignant transformation of OLP.

Correlation between tissue expression of microRNA-137 and CD8 in oral lichen planus.

OBJECTIVES: Oral lichen planus (OLP) is a chronic, inflammatory condition, classified by the World Health Organization as a premalignant lesion. We performed this study to evaluate the correlation between microRNA-137 (miR-137) and CD8 oral tissue expression in OLP patients. MATERIALS AND METHODS: Twenty OLP patients [classified into three groups: (a) papular, reticular, or plaque; (b) atrophic; and (c) erosive] and 20 healthy controls were subjected to biopsy of the oral mucosa. To evaluate CD8 tissue expression, we performed immunohistochemical examination, followed by immunostaining and computerized quantification. The expression of miR-137 was evaluated using real-time quantitative PCR. We used SPSS software (version 15 for windows) to perform the statistical analysis. RESULTS: Our analysis showed an increased tissue expression of CD8 (p < 0.01) and reduced expression of miR-137 (p < 0.001) in OLP patients, compared to the control group. Moreover, there was a statistically significant difference (p = 0.001) between OLP subgroups in terms of CD8 tissue expression [highest in erosive OLP and lowest in papular/reticular/plaque OLP]. However, these subgroups showed no significant difference (p = 0.168) in terms of miR-137 expression. A negative correlation (p < 0.05) between tissue expression of miR-137 and CD8 was noted with a varying correlation coefficient in different OLP subgroups (-0.250 in erosive OLP, -0.491 in atrophic OLP and -0.616 in papular/reticular/plaque OLP). CONCLUSIONS: Our findings indicate reduced expression of miR-137 and a reverse correlation between tissue expression of miR-137 and CD8 in the oral mucosa of OLP patients. CLINICAL RELEVANCE: Future studies should investigate the therapeutic potential of miR-137 overexpression in OLP patients.

Malignant transformation of oral lichen planus and oral lichenoid lesions: A meta-analysis of 20095 patient data.

OBJECTIVES: For over a century, a heated debate existed over the possibility of malignant transformation of oral lichen planus (OLP). We performed this meta-analysis to evaluate the malignant potential of OLP and oral lichenoid lesions (OLL) and investigate the possible risk factors for OLP malignant transformation into oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: We searched Medline, Scopus, and Web of Knowledge for relevant observational studies. Data on OLP malignant transformation were calculated as a pooled proportion (PP), using the Der-Simonian Liard method. We performed subgroup analyses by OLP diagnostic criteria, site, and clinical type, using Open Meta[Analyst] software. Data on possible risk factors for malignant transformation were pooled as odds ratios (ORs), using Comprehensive Meta-Analysis software. RESULTS: Pooling data for OLP malignant transformation from 57 studies (19,676 patients) resulted in an overall PP of 1.1% [95% CI: 0.9%, 1.4%], while pooling data from 14 recent studies that used the World Health Organization-2003 diagnostic criteria resulted in an overall-PP of 0.9% [95% CI: 0.5%, 1.3%]. The risk of malignant transformation was higher (PP=2.5%, 95% CI [1%, 4%]) in OLL patients (419 patients). A significant increase of malignant transformation risk was noted among smokers (OR=2, 95% CI [1.25, 3.22]), alcoholics (OR=3.52, 95% CI [1.54, 8.03]), and HCV-infected patients (OR=5, 95% CI [1.56, 16.07]), compared to patients without these risk factors. CONCLUSION: A small subset of OLP patients (1.1%) develop OSCC; therefore, regular follow-up for these patients is recommended. A higher incidence of malignant transformation was found among smokers, alcoholics, and HCV-infected patients; however, these associations should be further investigated.