Deschaine, Maria

AbstractVulvar lichen planus (VLP) is a chronic inflammatory disease which adversely affects patients' quality of life. The pathogenesis of VLP is unknown although Th1 immune response has been implicated. We aimed to discover specific tissue‐based protein biomarkers in VLP compared to normal vulvar tissue (NVT), vulvar lichen sclerosus (VLS) and oral lichen planus (OLP). We used laser capture microdissection‐liquid chromatography‐ tandem mass spectrometry to assess protein expression in fixed lesional mucosal specimens from patients with VLP (n = 5). We then compared proteomic profiles against those of NVT (n = 4), VLS (n = 5), OLP (n = 6) and normal oral mucosa (n = 5), previously published by our group. IL16, PTPRC, PTPRCAP, TAP1 and ITGB2 and were significantly overexpressed in VLP compared to NVT. Ingenuity pathway analysis identified antigen presentation and integrin signalling pathways. Proteins overexpressed in both VLP versus NVT and OLP versus NOM included IL16, PTPRC, PTPRCAP, TAP1, HLA‐DPB1, HLA‐B and HLA‐DRA. This proteomic analysis revealed several overexpressed proteins in VLP that relate to Th1 autoimmunity, including IL16. Overlapping pathways, including those involving IFNγ and Th1 signalling, were observed between VLP, VLS, and OLP.

AbstractOral lichen planus (OLP) confers an approximately 1% risk of transformation to oral squamous cell carcinoma (OSCC). Early identification of high‐risk OLP would be very helpful for optimal patient management. We aimed to discover specific tissue‐based protein biomarkers in patients with OLP who developed OSCC compared to those who did not. We used laser capture microdissection– and nanoLC–tandem mass spectrometry to assess protein expression in fixed lesional mucosal specimens in patients with indolent OLP (no OSCC after at least 5‐year follow‐up, n = 6), transforming OLP (non‐dysplastic epithelium with lichenoid inflammation marginal to OSCC, n = 6) or normal oral mucosa (NOM, n = 5). Transforming OLP protein profile was enriched for actin cytoskeleton, mitochondrial dysfunction and oxidative phosphorylation pathways. CA1, TNNT3, SYNM and MB were overexpressed, and FBLN1 was underexpressed in transforming OLP compared with indolent OLP. Integrin signalling and antigen presentation pathways were enriched in both indolent and transforming OLP compared with NOM. This proteomic study provides potential biomarkers, such as CA1 overexpression, for higher‐risk OLP. While further validation studies are needed, we propose that epithelial–mesenchymal transition may be involved in OLP carcinogenesis.

AbstractVulvar lichen sclerosus (VLS) confers approximately 3% risk of malignant transformation to vulvar squamous cell carcinoma (VSCC). We used unbiased proteomic methods to identify differentially expressed proteins in tissue of patients with VLS who developed VSCC compared to those who did not. We used laser capture microdissection‐ and nanoLC‐tandem mass spectrometry to assess protein expression in individuals in normal vulvar tissue (NVT, n = 4), indolent VLS (no VSCC after at least 5 years follow‐up, n = 5) or transforming VSCC (preceding VSCC, n = 5). Interferon‐γ and antigen‐presenting pathways are overexpressed in indolent and transforming VLS compared to NVT. There was differential expression of malignancy‐related proteins in transforming VLS compared to indolent VLS (CAV1 overexpression, AKAP12 underexpression), particularly in the EIF2 translation pathway, which has been previously implicated in carcinogenesis. Results of this study provide additional molecular evidence supporting the concept that VLS is a risk factor for VSCC and highlights possible future biomarkers and/or therapeutic targets.

AbstractBackgroundOral lichen planus confers a 1% risk of transformation to oral squamous cell carcinoma. While prior exome sequencing studies have identified multiple genetic mutations in oral squamous cell carcinoma, mutational analyses of lichen planus‐derived OSCC are lacking. We sought to clarify genomic events associated with oral lichen planus transformation.MethodsUsing rigorous diagnostic criteria, we retrospectively identified patients with non‐transforming oral lichen planus (i.e., known to be non‐transforming with 5 years of clinical follow‐up; n = 17), transforming oral lichen planus (tissue marginal to oral squamous cell carcinoma, n = 9), or oral squamous cell carcinoma arising in lichen planus (n = 17). Gene mutational profiles derived from whole‐exome sequencing on fixed mucosal specimens were compared among the groups.ResultsThe four most frequently mutated genes in transforming oral lichen planus and oral squamous cell carcinoma (TP53, CELSR1, CASP8, and KMT2D) identified 12/17 (71%) of oral squamous cell carcinomas and 5/9 (56%) of transforming oral lichen planus but were absent in non‐transforming oral lichen planus. We identified other known oral squamous cell carcinoma mutations (TRRAP, OBSCN, and LRP2) but also previously unreported mutations (TENM3 and ASH1L) in lichen planus‐associated oral squamous cell carcinomas.ConclusionsThese findings suggest alterations in DNA damage response and apoptosis pathways underlie lichen planus‐related oral squamous cell carcinoma transformation and are supported by mutational signatures indicative of DNA damage. This study characterized patterns of mutational events present in oral lichen planus associated with squamous cell carcinoma and in squamous cell carcinoma associated with oral lichen planus but not in non‐transforming oral lichen planus.

AbstractBackgroundUnderstanding whether specific histopathologic features on skin biopsy are predictive of systemic associations in dermatomyositis (DM) would be useful to guide clinical screening.MethodsThrough retrospective medical record search, clinical and laboratory findings of patients with DM were documented. Existing skin biopsy slides were re‐reviewed blindly.ResultsOf all biopsy specimens (n = 42), the most frequent histopathological finding was vacuolar interface dermatitis (95%). Other features included perivascular lymphocytic infiltrate (71%), increased dermal mucin (40%), vessel wall thickening (12%), follicular plugging (9.5%), and dermal sclerosis (7%). Neutrophilic infiltrate was observed in three biopsies from a patient with adalimumab‐associated DM. Vasculitis was not observed. There was no statistically significant difference in the presence of any histopathological feature and that of various systemic manifestations (i.e., myopathy, interstitial lung disease [ILD] and malignancy). However, we observed that dense lichenoid infiltrate rather than pauci‐inflammatory changes correlated with severe itching (p < 0.001). Patients with MDA‐5 antibodies were significantly more likely to have vasculopathy than those without (p = 0.029*).ConclusionsNo dermatopathologic feature was reliably predictive of myopathy, ILD, or malignancy. This finding implies that, regardless of histopathologic findings, patients should be screened for associated conditions as clinically indicated.