Role of miR‑155 in immune regulation and its relevance in oral lichen planus (Review)

Abstract

Oral lichen planus (OLP) is a chronic mucosal inflammatory disease. The World Health Organization has described it as a potentially malignant condition. The pathogenesis of OLP remains to be fully elucidated, but extensive evidence suggests that immunologic and inflammatory factors have important roles. MicroRNAs (miRs), which are small non-coding RNAs, have been reported to be involved in OLP. In particular, miR-155 is significantly upregulated in patients with OLP. miR-155 has numerous functions and is closely linked to inflammation and immune system regulation. However, in-depth studies of the mechanisms via which miR-155 is involved in OLP are currently insufficient. Considering the close association between miR-155 and immune regulation as well as the importance of immune factors in OLP, the role of miR-155 in the immune system was herein summarized with a focus on OLP. The present review provides a basis for further study of the molecular mechanisms underlying the development and progression of OLP.

Assessment of miR-155 in Saliva of Oral Lichen Planus Patients as a Potential Biomarker of Malignant Transformation Before and After Topical Corticosteroid Therapy

“…The significantly elevated miR155 levels encountered in our study in OLP patients before starting corticosteroid therapy in comparison with controls were in line with former studies recording an upregulated expression of miR-155 in OLP patients 1 . A different study reported an overexpression of miR-155 in peripheral blood monocytes in OLP lesions compared with controls and revealed a close association of its expression with the disease severity 3 . Another study surveyed the erosive type of OLP and identified a positive miR-155-IFN-γ interaction, further enhancing the Th1 mediated immune response in OLP 14 .…”

“…The association of miRNAs with OLP has been previously reviewed, and a close association was revealed between miR-155 and cytokines linked with OLP, making it a perfect research nominee in OLP 10 . A positive relation was recognized between IFN-γ and miR-155, resulting in a Th1-mediated immune response in OLP 3 . Moreover, it has been proposed that miR-155 is involved in T cells differentiation toward Th1 via IFN-γ signaling.…”

“…Oral lichen planus (OLP) is an immune mediated disorder that involves the oral mucosal tissue with a diversity of clinical appearances, such as reticular, atrophic, erosive and ulcerative forms 1 , affecting 1-2% of the population mainly females 2 . It has the potential for malignant transformation; where 1-2% of OLP lesions have been reported to turn into oral squamous cell carcinoma 3 . Though there is no precise understanding of the pathogenesis or etiology of OLP up till now, it has been hypothesized that OLP is a T cell-induced autoimmune disorder, characterized by an exacerbated Th1 and cytotoxic T-lymphocytes (CTLs) responses 1 .…”

“…Moreover, it has been proposed that miR-155 is involved in T cells differentiation toward Th1 via IFN-γ signaling. Nevertheless, the specific role of miR-155 in OLP pathogenesis is up till now largely obscure 3 .…”

Clinical Values of miR-23a-3p in Oral Lichen Planus and Its Role in Keratinocyte Proliferation and Inflammatory Response

“… 11 In addition, several miRNAs have been detected to be aberrantly expressed in OLP cases, such as miR-155, miR-27b, and so on. 12 , 13 MiR-23a-3p is a member of the miR-23a-27a-24-2 cluster, it has been suggested to exert its biological functions in different cancers through regulating cellular activation, cell motility and immune cell infiltration. 14 , 15 In a study reported by Chen et al, miR-23a-3p was identified to be downregulated in the tissues of oral squamous cell carcinomas (OSCCs) patients, and overexpression of miR-23a-3p was suggested to suppress tumor proliferation and invasion of OSCC.…”