Metabolic changes during malignant transformation in primary cells of oral lichen planus: Succinate accumulation and tumour suppression

Oral squamous cell carcinoma (OSCC) is usually diagnosed at late stages, which leads to high morbidity. There are evidence that chronic inflammation (eg oral lichen planus [OLP]) was a risk factor of OSCC, but often misdiagnosed or ignored until invasion and metastasis. By applying precision medicine, the molecular microenvironment variations and relevant biomarkers for the malignant transformation from OLP to OSCC can be fully investigated. Several studies pointed out that the metabolic pathway were suppressed in OSCC. However, it remains unclear how the systemic profile of the metabolites change during the malignant transformation. In this study, we examined and compared the mucosa samples from 11 healthy individuals, 10 OLP patients and 21 OSCC patients. Based on the results, succinate, a key metabolite of the tricarboxylic acid cycle pathway, was accumulated in the primary cultured precancerous OLP keratinocytes and OSCC cells. Then, we found that succinate activated the hypoxia‐inducible factor‐1 alpha (HIF‐1α) pathway and induced apoptosis, which could also be up‐regulated by the tumour suppressor lncRNA MEG3. These results suggested the critical roles of succinate and MEG3 in the metabolic changes during malignant transformation from OLP to OSCC, which indicated that succinate, HIF1α and downstream proteins might serve as new biomarkers of precancerous OLP for early diagnosis and therapeutic monitoring. In addition, succinate or its prodrugs might become a potential therapy for the prevention or treatment of OSCC.     

Association of HLA-te22 antigen with anti-nuclear antibodies in Chinese patients with erosive oral lichen planus

The purpose of this study was to determine the frequencies of the presence of serum anti-nuclear antibodies (ANA) and smooth muscle antibodies (SMA) in 76 patients with oral lichen planus (OLP), in 77 patients with other oral mucosal diseases, and in 41 healthy control subjects. HLA phenotypes in some of the patients with OLP and recurrent aphthous ulcers (RAU) were determined to show whether there was an association of HLA antigens with the presence of autoantibodies. Indirect immunofluorescence techniques with mouse liver or stomach as the substrate were used to detect the serum ANA or SMA, respectively. The B lymphocytes isolated from peripheral blood were used for HLA typing by means of a standard microcytotoxicity assay. We found that the positive rate of serum ANA in patients with OLP (29%, p < 0.01), especially in patients with erosive OLP (34%, p < 0.001), was significantly higher than that in the normal control subjects (5%). The frequency of serum SMA in patients with OLP (20%, p < 0.01), in patients with RAU (17%, p < 0.01), or in patients with oral squamous cell carcinomas (41%, p < 0.001) was also significantly higher than that in normal control individuals (0%). In the erosive OLP group, the HLA-Te22 antigen occurred more frequently in patients with positive ANA (75%, p < 0.05) than in those with negative ANA (25%). We conclude that there is an association of HLA-Te22 antigen with ANA in Chinese patients with erosive OLP.     

Update of the cancer-associated molecular mechanisms in oral lichen planus, a disease with possible premalignant nature

Oral lichen planus (OLP) is a relatively common inflammatory disease. Several reports of oral squamous cell carcinomas (OSCC) developing in the ground of previous OLP lesions exist in the current medical literature. Hence, there is a debate concerning the possible premalignant nature of OLP. The studies that examined the malignant potential of OLP for many years were mainly observational and were seeking to detect the percentage of OLP patients that developed OSCC. The results of these studies varied significantly with reported percents of malignant transformation of OLP ranging from 0 to 12.5%. In recent years the number of OLP studies that investigate molecular biomarkers identified in cancer is on the rise. This article is an update of the molecular pathways identified in OLP that could be suggestive of a malignant potential of this condition.     

Phenotypic variability and therapeutic implications of Candida species in patients with oral lichen planus

We investigated the prevalence and phenotypic variation of Candida species in oral lichen planus (OLP) and the therapeutic implications of our findings. Eighty patients with clinically and histopathologically confirmed cases of OLP (64 non-erosive, 16 erosive) and a control group of 80 healthy individuals with no predisposing factors for oral candidiasis were examined for evidence of Candida infection. Oral swabs and smears were obtained for cytology and culture. Identification, speciation and antifungal susceptibility tests of Candida isolates were performed using an automated microbial identification system. Fifty percent of erosive OLP cases, 28% of non-erosive cases and none of the controls showed evidence of Candida. Candida albicans was found predominantly in non-erosive OLP, while other Candida species were predominate in erosive OLP. Non-Candida albicans isolates (C. glabrata, C. krusei) were resistant to the commonly used antifungals, clotrimazole and fluconazole. Candida infection is common in cases of OLP. We recommend antifungal sensitivity testing prior to antifungal therapy for the erosive form of OLP.     

A randomized, placebo-controlled, double-blind clinical trial of curcuminoids in oral lichen planus.

We studied the efficacy of curcuminoids in the treatment of oral lichen planus (OLP), a chronic, mucocutaneous, immunological disease. Curcuminoids are components of turmeric (Curcuma longa) that have anti-inflammatory activity. Turmeric has been used in Ayurveda (Indian traditional medicine) for centuries. A randomized, double-blind, placebo-controlled trial was conducted. In all, 100 consecutive, eligible patients with OLP presenting to the oral medicine clinic at the University of California, San Francisco, were to be selected. Two interim analyses were to be conducted during the trial. The trial was conducted between February 2003 and September 2004. The first interim analysis was conducted in October 2004 using data from the first 33 subjects. Study subjects were randomized to receive either placebo or curcuminoids at 2000 mg/day for 7 weeks. In addition, all subjects received prednisone at 60 mg/day for the first 1 week. The primary outcome was a change in symptoms from baseline. Secondary outcomes were changes in clinical signs and occurrence of side effects. The first interim analysis did not show a significant difference between the placebo and curcuminoids groups. Conditional power calculations suggested a less than 2% chance that the curcuminoids group would have a significantly better outcome as compared with the placebo group if the trial were continued to completion. Therefore, the study was ended early for futility. Reaching a conclusion regarding the efficacy of curcuminoids based on the results of this study is not possible as it was ended early for futility. Curcuminoids at this dose were well tolerated and the results suggest that for future studies a larger sample size, a higher dose and/or longer duration of curcuminoids administration should be considered; however, for the next step, an RCT of a shorter duration, using a higher dose of curcuminoids, and without an initial course of prednisone, should be considered.     

LCK, survivin and PI-3K in the molecular biomarker profiling of oral lichen planus and oral squamous cell carcinoma

T cell signaling is critical in oral lichen planus (OLP) based on the pathogenesis of this chronic inflammatory autoimmune mucocutaneous lesion. Lck plays a key role in T cell signaling; ultimately this signaling affects other targets such as PI-3K. Excessive activity in PI-3K inhibits apoptosis and promotes uncontrolled cell growth. Molecular biomarker profiling in OLP, Chronic Interface Mucosities (CIM), Epithelial Dysplasia (EpD) and Oral Squamous Cell Carcinoma (SCCA) with application of the principle of biomarker voting may represent a new frontier in the diagnosis, assessment and the arguable debate of OLP transformation to cancer. The presence of Lck, PI-3K and Survivin, a cancer specific anti-apoptotic protein was assessed, using immunohistochemistry and tissue micro-array on patient samples, in OLP, SCCA, CIM and EpD. Lck expression was very high in 78.6 % of OLP patients compared to 3.7% in SCCA; PI-3K was high in 63% of SCCA, 100% of EpD, and 35.7% OLP cases. Survivin was high in 64.3% of OLP cases, 96.3% of SCCA, and 100% of EpD. CIM cases may be slightly different molecularly to OLP. Taken together, our data suggest that biomarker protein voting can be effectively used to isolate high-risk OLP cases. Specifically, we show data with four remarkable cases demonstrating that molecular factors are predictive of histopathology. We conclude that it is safer to treat OLP as premalignant lesions, to adopt aggressive treatment measure in histopathologic described well and moderately differentiated SCCA, and to monitor progress of these diseases molecularly using individualized auto-proteomic approach. The use of Lck inhibitors in OLP management needs to be investigated in the future.     

Analysis of oral microbial community and Th17‐associated cytokines in saliva of patients with oral lichen planus

Oral lichen planus (OLP) is a chronic inflammatory disorder of oral mucosa of unknown cause. Microbial infection and dysimmunity appear to play important roles in its pathogenesis. In this study, differences in genetic profiling of salivary microbial communities in two subtypes of OLP and healthy controls were evaluated by means of PCR‐denaturing gradient gel electrophoresis (DGGE). Additionally, ELISA was used to investigate the possible role of Th17 in lesion formation by detecting two related cytokines IL‐17 and IL‐23 in the saliva of OLP patients. When the DGGE profiles were analyzed, the bacterial populations were found to be significantly less rich in subjects with reticular and erosive OLP than in healthy controls. There was significantly less microbial diversity, as denoted by the Shannon index, in saliva samples from subjects with erosive OLP than in those from healthy controls. Cluster analysis and principal component analysis showed that the DGGE profiles formed distinctly group‐specific clusters. Salivary concentrations of IL‐17 in subjects with erosive OLP group were significantly higher than in those with reticular OLP and healthy controls. What's more, significantly positive correlations were observed between salivary IL‐17 concentrations and disease clinical scores. Microbial richness and diversity was negatively correlated with salivary IL‐17 concentrations. These results suggest there is significantly less salivary bacterial diversity and complexity in subjects with OLP han in healthy controls and that the shifted community composition is closely related to an immune cytokine, IL‐17.     

细胞免疫功能及辅助型T细胞因子在口腔扁平苔藓中的作用

目的 探讨细胞免疫功能及辅助型T细胞（Th）细胞因子在口腔扁平苔藓（OLP）中的作用。方法 以35例糜烂型（糜烂组）及29例网纹型OLP（网纹组）患者为对象,选取同期20例健康人为对照组,流式细胞术检测外周血中T细胞、B细胞、NK细胞和调节性T细胞亚群表达百分率。ELISA法检测外周血中TNF-α和INF-γ（Th1型细胞因子）,IL-4和IL-10（Th2型细胞因子）,IL-17、IL-23（Th17型细胞因子）含量;分离外周血单个核细胞,qRT-PCR检测上述因子mRNA的表达。结果 与健康组相比,OLP患者CD3+、CD4+ T细胞亚群比例（F=3.211和3.565,P<0.05）及CD4+/CD8+降低（F=3.430,P<0.05）,CD4+Foxp3+调节性T细胞亚群比例（F=3.370,P<0.05）及外周血中TNF-α、INF-γ、IL-4、IL-10、IL-17、IL-23含量增高（F=0.923、0.820、1.043、1.132、0.745和0.802,P<0.05）。与网纹组相比,糜烂组CD8+ T细胞亚群比例较低（t=2.450,P<0.05）;IL-4、IL-10蛋白（t=22.780和25.112,P<0.05）及mRNA较低（t=3.781和6.710,P<0.05）,IL-17、IL-23蛋白（t=15.765和19.307,P<0.05）及mRNA较高（t=4.022和8.569,P<0.05）。结论 口腔扁平苔藓患者存在细胞免疫紊乱及Th细胞因子异常,其中CD8+及Th17型细胞与糜烂型OLP发病有关,Th2型细胞与网纹型OLP发病有关。     

Image cytometric evaluation of nuclear texture features and DNA content of the reticular form of oral lichen planus

OBJECTIVE: To analyze image cytometric chromatin changes reflected in nuclear texture features and DNA ploidy of oral lichen planus in relation to the normal buccal mucosa and buccal mucosa expressing malignancy-associated changes in cancer patients. STUDY DESIGN: Twenty-eight patients with the reticular form of oral lichen planus, with a follow-up period of 25 years, 50 healthy controls and 50 lung cancer patients were included in the study. Scrapings of buccal mucosa were suspended in transport medium. Monolayer filter preparations were Feulgen-thionin stained. Image cytometric analysis was performed by Cyto-Savant. RESULTS: All oral lichen planus specimens in our study were diploid. In univariate analysis, differences between the normal buccal mucosa and oral lichen planus were found in several nuclear texture features, which gave an 80% correct classification rate in multivariate analysis. In the second part of the study, the classifier that recognizes malignancy-associated changes on the buccal mucosa of patients with lung cancer correctly recognized > 80% of oral lichen planus samples as normal buccal mucosa. CONCLUSION: Our results indicate that chromatin changes in oral lichen planus exist compared to normal cells; however, the chromatin structure of the reticular form of oral lichen planus does not express malignancy-associated changes and is more similar to normal squamous cells.     

Thorough clinical evaluation of skin, as well as oral, genital and anal mucosa is beneficial in lichen planus patients

Lichen planus (LP) is a common mucocutaneous disease of unknown aetiology with various geographical prevalence, may be related to some serious disorders such as squamous cell carcinoma and often remains underdiagnosed. The aim of this retrospective study was to thoroughly determine localization and clinical characteristics of LP lesions in a cohort of 173 Slovenian patients in association to the presence of accompanying symptoms and history of potential stressful events. Isolated cutaneous lesions of LP were found in 56.6% and isolated oral LP in 3.5% of patients. Thirty-four percent presented orocutaneous LP, whereas genitocutaneous LP was noted in 1.2%, orogenito-cutaneous LP in 4% and orogenital LP in 0.5% of patients. Underlying stressful events were noted in 36 out of 137 (26.3%) patients. Despite obviously visible localization of the lesions various medical specialists should be familiar with LP and thoroughly examine the complete skin, as well as oral, genital and anal mucosa in each LP patient to avoid a delay in diagnosing this disease and possibly disclose a much serious underlying condition. Psychological support should be offered, if needed.     

Compartmentalization of the Mitogen-Activated Protein Kinase (MAPK) in Hepatic Endosomes: Association with the Internalized Epidermal Growth Factor (EGF) Receptor

A pool of MAPK was found in hepatic plasma membrane (PM) and endosomes (ENs). After injection of a single dose of EGF (10 μg/100 g body weight), MAPK was detected in EGF receptor (EGFR) immunoprecipitates prepared from ENs. MAPK was detected in a time-dependent manner in EGFR immunoprecipitates that was coincident with the progressive concentration of the EGFR. The EGFR-associated MAPK was also detected by using an anti-phospho-MAPK suggesting that it was active. MAPK was present in wheat-germ agglutinin (WGA) eluates prepared from ENs and was maximally tyrosine-phosphorylated at the time peak of EGFR internalization. MAPK therefore is compartmentalized in PM and ENs of rat liver. A fraction of the endosomal MAPK was found to be associated with the internalized EGFR complexes, suggesting that it plays a role in the control of the EGFR activity at this locus.     

GPC1 exosome and its regulatory miRNAs are specific markers for the detection and target therapy of colorectal cancer

Colorectal cancer (CRC) is the second leading cause of cancer‐related deaths worldwide. However, a biomarker for a sensitive and simple diagnostic test and highly effective target therapy of CRC is still clinically unavailable. This study is to investigate the evidence and significance of plasma GPC1 positive exosomes as a biomarker of CRC. Results showed that GPC1⁺ exosomes were successfully isolated from tissues and plasma. The percentage of GPC1⁺ exosomes and the GPC1 protein expression in exosomes from tumour tissues and plasma of CRC patients before surgical treatment was significantly elevated compared to that in the peritumoural tissues and the plasma of healthy controls. miR‐96‐5p and miR‐149 expression in tumour tissues and plasma of CRC patients as well as in the GPC1⁺ exosomes from CRC patients were significantly decreased compared to that in the peritumoural tissues and the plasma of healthy controls. Two months after surgical treatment, levels of all tested markers significantly normalized. Overexpression of miR‐96‐5p and miR‐149 significantly decreased GPC1 expression in HT‐29 and HCT‐116 cells, xenograft tumours, plasma in mice bearing HT‐29 and HCT‐116 tumours, and the secretion of GPC1⁺ exosomes from the HT‐29 and HCT‐116 cells and xenograft tumours. Overexpression of miR‐96‐5p and miR‐149 significantly decreased cell viability and increased cell apoptosis in HT‐29 and HCT‐116 cells, and inhibited the growth of xenograft HT‐29 and HCT‐116 tumours. In conclusion, the increased plasma GPC1⁺ exosomes and reduced plasma miR‐96‐5p and miR‐149 expression are specific markers for the diagnosis of CRC and targets for the therapy of CRC.