Analysis of mRNA Expression in Epithelial Layers of Oral Lichen Planus by Laser Microdissection with RT-PCR

Abstract

Oral lichen planus (OLP) is a common chronic inflammatory disease of oral mucosa ; however, the precise mechanisms for the formation of OLP have not been elucidated. Laser microdissection is a useful tool for the isolation of target cells from tissue sections. In the present study, we adopted the laser capture microdissection system for analysis of various mRNA expressions in the epithelial cell layers from biopsy samples of OLP. Target epithelial cell layers were harvested by laser microdissection from specimens of OLP or normal gingival tissues. Total RNA was isolated from those epithelial cell layers and TNF-α-specific, IL-8-specific, and IFN-γ-specific mRNAs were amplified by a modified standard reverse transcription-polymerase chain reaction (RT-PCR). After 40 cycles of amplification, a housekeeping gene was detected in as little as 77,000 μm2 of epithelial cell layers of OLP. Analysis of expressions for TNF-α, IFN-γ, and IL-8 demonstrated that OLP, but not control samples, expressed messages specific for TNF-α and IFN-γ. In contrast, no IL-8-specific mRNA was detected in the epithelial region of either the OLP or the control sample. These results indicate that laser microdissection can be used for analysis of mRNA expressions in targeted epithelial cell layers of OLP and thus for elucidation of mechanisms for the development of OLP.