ABSTRACT Background Oral lichen planus (OLP) is a chronic T‐cell‐mediated immune disease of unknown aetiology. MicroRNA (miRNAs) are short non‐coding RNAs capable of regulating mRNA and may have roles in T‐cell‐related diseases. The aim of this study was to investigate the profile of miRNAs in OLP patients and its interaction with potential target genes. Methods Total RNA was extracted from fresh frozen biopsies from 24 patients with OLP and 8 control patients. The NanoString Counter Analysis System was used to analyse total RNA samples for differential miRNA expression. NanoString expression was confirmed by RT‐qPCR analysis. Genes potentially targeted by upregulated and downregulated miRNAs were identified, and RT‐qPCR was employed to investigate the expression of target genes in OLP and controls. Probability values < 0.05 were considered statistically significant. Results NanoString analysis showed that eight miRNAs, miR‐155, miR‐146a, miR‐3195, miR‐342, miR‐4516, miR‐21, miR‐29a and miR‐193 were upregulated in OLP tissues. Contrarily, the other eight miRNAs, miR‐221, miR‐200b, miR‐149, miR‐205, miR‐27b, miR‐95, miR‐127b, miR‐95, miR‐206 were downregulated in OLP tissues. NanoString findings have been confirmed by RT‐qPCR results for four upregulated miRNAs, miR‐155, miR‐146a, miR‐29a and miR‐342, and one downregulated miRNA, namely miR‐205. The expression of two target genes, namely MYC for miR‐29a and interleukin‐24 (IL‐24) for miR‐205, was found to negatively correlate with the respective miRNA. This suggests that MYC and IL‐24 could be regulated by the above miRNAs in OLP. Conclusions The work presented in this study suggests that miRNAs could be involved in both the immunopathogenesis and malignant transformation of OLP.
Heba et al. (2026) studied this question.