Changes in miRNA expression in sera and correlation to duration of disease in patients with multifocal mucosal lichen planus

BACKGROUND: Mucosal lichen planus is a severe variant of lichen planus, Lichen planus (LP), which in many ways affect patients' lives. The aetiology is not fully understood, and there is no treatment clearing the disease once and for all. Oral LP has by the WHO been classified as a precancerous lesion. Micro-RNAs, miRNAs, are non-coding, small single-stranded RNAs involved in biological processes like apoptosis, proliferation, differentiation, metastasis, angiogenesis and immune response. METHODS AND RESULTS: In sera from 30 patients with multifocal mucosal LP, 15 miRNAs were identified as significantly differentially expressed compared with controls. The three most up-regulated miRNAs are all connected to oral squamous cell carcinoma or epithelial carcinoma in general. DISCUSSION: Even if no specific LP-associated miRNA profile was found, data clearly indicate that miRNAs could play a role in the earlier phases of lichen planus. J Oral Pathol Med (2012) 41: 8689