ABSTRACT
OBJECTIVE: The objective of this study was to investigate the expression of Toll-like receptors (TLR) and TLR-associated signalling pathway genes in oral lichen planus (OLP). METHODS: Initially, immunohistochemistry was used to determine TLR expression in 12 formalin-fixed archival OLP tissues with 12 non-specifically inflamed oral tissues as controls. RNA was isolated from further fresh samples of OLP and non-specifically inflamed oral tissue controls (n = 6 for both groups) and used in qRT(2)-PCR focused arrays to determine the expression of TLRs and associated signalling pathway genes. Genes with a statistical significance of ±two-fold regulation (FR) and a P-value < 0.05 were considered as significantly regulated. RESULTS: Significantly more TLR4(+) cells were present in the inflammatory infiltrate in OLP compared with the control tissues (P < 0.05). There was no statistically significant difference in the numbers of TLR2(+) and TLR8(+) cells between the groups. TLR3 was significantly downregulated in OLP (P < 0.01). TLR8 was upregulated in OLP, but the difference between the groups was not statistically significant. The TLR-mediated signalling-associated protein genes MyD88 and TIRAP were significantly downregulated (P < 0.01 and P < 0.05), as were IRAK1 (P < 0.05), MAPK8 (P < 0.01), MAP3K1 (P < 0.05), MAP4K4 (P < 0.05), REL (P < 0.01) and RELA (P < 0.01). Stress proteins HMGB1 and the heat shock protein D1 were significantly downregulated in OLP (P < 0.01). CONCLUSION: These findings suggest a downregulation of TLR-mediated signalling pathways in OLP lesions.
Subject(s)
Lichen Planus, Oral/metabolism , Toll-Like Receptors/metabolism , Down-Regulation , Female , HMGB1 Protein/metabolism , HSP70 Heat-Shock Proteins/metabolism , Humans , Immunohistochemistry , Lichen Planus, Oral/genetics , Lichen Planus, Oral/pathology , Male , Membrane Glycoproteins/genetics , Membrane Glycoproteins/metabolism , Middle Aged , Mouth Mucosa/metabolism , Myeloid Differentiation Factor 88/genetics , Myeloid Differentiation Factor 88/metabolism , Receptors, Interleukin-1/genetics , Receptors, Interleukin-1/metabolism , Signal Transduction , Toll-Like Receptors/biosynthesis , Toll-Like Receptors/genetics , Up-RegulationABSTRACT
BACKGROUND: Malignant mesothelioma is a rare neoplasm that usually develops after exposure to asbestos and particularly involves the pleural cavity. It has a poor prognosis with aggressive local invasion and metastatic spread. METHODS: The literature relating to malignant mesothelioma metastatic to the oral region was reviewed. RESULTS: In all, 14 cases of malignant mesothelioma metastatic to the oral cavity were found. All were from pleural mesotheliomas, the tongue was the most common site of metastasis (8/14), and most metastases (9/13) were of the epithelioid type. The newly reported case is only the second report of a mesothelioma metastasizing to the buccal mucosa. It showed strong immunopositivity for keratin markers, vimentin, calretinin, and Wilms tumor product-1. CONCLUSIONS: The incidence of mesothelioma is predicted to continue to increase for at least another decade. Clinicians and pathologists should be aware of this lesion and its propensity to metastasize to the oral cavity.
