Oral lichen planus as a preneoplastic inflammatory model

Hydroxychloroquine is effective in oral lichen planus: A multicenter, randomized, controlled trial

OBJECTIVES

This study was aimed to evaluate the safety and benefit of short-term application of hydroxychloroquine in the management of atrophic/erosive/ulcerative oral lichen planus (OLP).

METHODS

This multicenter, randomized, controlled, evaluator-blinded, prospective clinical trial was performed from October 1, 2019, to September 1, 2022. A total of 99 patients were randomized to receive systemic use of hydroxychloroquine (n = 50), or topical use of 0.05% dexamethasone (n = 49) for 4 weeks. The response to both treatment modalities was evaluated according to reticulation, hyperemic, and ulceration (RHU) score and visual analog scale (VAS) score.

RESULTS

After 4 weeks of medication, both groups showed substantial reduction in RHU and VAS score (p < 0.05). In hydroxychloroquine group, the average of RHU score was reduced from 10.60 to 7.68 (dropped 27.49%), and the average of VAS score was reduced from 3.74 to 2.47 (dropped 34.09%). There were no differences between the two groups in reduction of RHU score and VAS score (p > 0.05). Single factor analysis found hyperemic area (p = 0.019) and erosive/ulcerative area (p = 0.024) had impacts on drug efficacy of hydroxychloroquine, and logistic regression revealed that no factors (p > 0.05) influenced its efficacy.

CONCLUSION

These findings indicate hydroxychloroquine is a safe and effective agent in treating atrophic/erosive/ulcerative OLP.

Expression of epithelial growth factor receptor as a protein marker in oral reticular and erosive lichen planus

BACKGROUND

Oral lichen planus (OLP) is a chronic inflammatory mucosal disease that is classified as a premalignant condition. Epithelial growth factor receptor (EGFR) is associated with tumorigenesis and tumor progression and is overexpressed in several oral malignant disorders. Despite the association of EGFR overexpression with oral potentially malignant lesions, few studies have analyzed its expression in OLP, showing controversial results. This study aimed to compare the expression of EGFR as a protein marker in Reticular and Erosive OLP.

METHODS

This descriptive-analytical cross-sectional was conducted on 15 paraffin blocks of reticular lichen planus lesions, 16 paraffin blocks of erosive OLP lesions, and 8 paraffin blocks of inflammatory fibrous hyperplasia lesions as the control group (39 in total). After immunohistochemical staining for EGFR, samples were simultaneously observed by two maxillofacial pathologist, and the percentage of stained cells, intensity of staining, pattern of staining, and the location of stained cells were obtained.

RESULTS

The Mann-Whitney-U test showed that there was no significant difference in the mean percentage of stained cells between erosive OLP and reticular OLP (P-value = 0.213) and between reticular OLP and control group (P-value = 0.137), but there was a significant difference between erosive OLP and control group (P-value = 0.035). Fisher's exact test showed that there was no significant difference between the frequency distribution of staining patterns in three types of lesions (P-value = 0.90). Kruskal-Wallis test showed that there was no significant difference between the intensity of staining in the three groups (P-value = 0.19) and also there was no significant difference between the location of stained cells in different layers of the epithelium in the three groups (P-value = 0.90).

CONCLUSIONS

The results of this study showed that in comparison of reticular OLP, erosive OLP, and the control group there was a significant difference just between erosive OLP and control group in the percentage of stained cells.

Controversies regarding oral lichen planus and lichenoid-dysplastic lesions

Objective

Oral lichen planus (OLP) is an immune-mediated condition featuring chronic inflammation. The World Health Organization classifies OLP as potentially malignant, but it is believed that the malignant transformation of OLP occurs in lesions with both lichenoid and dysplastic features (LD). This review discusses the issues surrounding OLP and LD, including their malignancy, classification, and categorization, and whether lichenoid inflammation causes dysplastic changes in LD or vice versa.

Methods

English full-text literature on OLP, LD and/or dysplasia was retrieved from PubMed, CINAHL, and Google Scholar.

Results

Thirty-six publications including original research articles, reviews, meta-analyses, books, reports, letters, and editorials were selected for review.

Discussion

Research suggests that OLP has malignant potential, although small, and that LD should not be disregarded, as dysplasia presenting with or without lichenoid features may develop into cancer. There is also disagreement over the classification and categorization of LD. Different terms have been used to classify these lesions, including lichenoid dysplasia, OLP with dysplasia, and dysplasia with lichenoid features. Moreover, in LD, it is not clear if dysplasia or lichenoid infiltration appears first, and if inflammation is a response to dysplasia or if dysplasia is a response to the persistent inflammation. The main limitation in the literature is the inconsistency and subjective nature of histological diagnoses, which can lead to interobserver and intraobserver variation, ultimately resulting in the inaccurate diagnosis of OLP and LD.

Conclusion

Although further research is required to understand OLP and LD, both lesions should be considered potentially malignant and should not be disregarded.

Bridging the gaps: management of lichen planus subtypes in a joint dermatology-oral surgery clinic

Lichen planus (LP) presents with a range of clinical subtypes. It can affect the outer skin, involve the nails and present with alopecia and mucosal symptoms to varying degrees. LP of the outer skin mostly shows a self-limiting course; however, this is not the case for lichen planopilaris and the mucosa-affecting subtypes. The pathogenesis of LP is still incompletely understood. As a result, an effective, targeted therapy is currently lacking and different immunomodulatory approaches are being used in clinical practice. The management of patients with severe oral LP mucosae can be particularly challenging. Although the true risk remains controversial, oral LP is considered a risk factor for the development of squamous cell carcinoma and there is a need for regular screening. The quality of life in patients with LP is significantly impaired because of frequent clinical visits, pain, soreness, inability to eat certain foods, side effects to medication, frustrating therapy attempts and worry regarding cancer risk. We highlight here the advantages of an interdisciplinary dermatology and oral surgery clinic, which can address the domains of tooth status, nutrition, pain and malignant transformation and optimized patient management.

An improved scoring system for monitoring oral lichen planus: A preliminary clinical study

OBJECTIVES

To design an improved oral lichen planus (OLP) scoring system, which can be widely applied.

SUBJECTS AND METHODS

A new scoring system that took reticulation, hyperemia and ulceration (RHU) into account, named as RHU scoring system, was designed for OLP patients' management. The patients were also scored for the reticulation/erythema/ulcer (REU) scoring system, physician global assessment (PGA), numerical rating scale (NRS) and Oral Health Impact Profile-14 (OHIP-14). The reliability and validity analyses were utilized to assess the RHU scoring system. We further applied the RHU scoring system to examine the treatment outcomes of topical dexamethasone sodium phosphate and general hydroxychloroquine hydrochloride among OLP patients.

RESULTS

Forty-eight OLP patients from two medical centers were recruited. This new scoring system has reliability with an internal consistency index Cronbach α 0.49. The Pearson correlation of RHU score with PGA and REU score were 0.891 and 0.675 (p < 0.05) respectively, reflecting satisfactory standard validity. A 10% change in RHU score was used as the disease condition evaluation standard, reflecting satisfactory discriminating validity (t = -5.821, p < 0.001). During follow-ups, scores of all scales decreased at each re-visit. The drop between each visit of OHIP-14 fluctuated compared with the RHU system and NRS.

CONCLUSIONS

As a semi-quantitative score system, the RHU scoring system can reflect the severity of OLP patients with hyperemia and ulceration lesions more accurately and sensitively compared with other score systems, which provides the potential to be widely used.

ALDH1 immunoexpression in epithelial and stromal cells of oral lichen planus and lesions with lichenoid inflammatory infiltrate

BACKGROUND

Oral Lichen Planus is a potential malignant disorder and shares clinical and histopathological features with other similar lesions. ALDH1 is a specific biomarker for stem cells identification, however its role in stromal cells of immune inflammatory infiltrate has not been explored. The aim of this study was to investigate the ALDH1 immunoexpression in epithelial and stromal cells of Oral Lichen Planus and other lesions with lichenoid inflammatory infiltrate.

MATERIAL AND METHODS

64 samples of Oral Lichen Planus, Oral Lichenoid Lesions, Oral Leukoplakia and Unspecific Chronic Inflammation were included. ALDH1 was evaluated in both epithelium and stromal cells. ALDH1+ cells ≥ 5% were considered positive in epithelium. Stromal cells were evaluated semi quantitatively. Fields were ranked in scores, according to criteria: 1 (0 to 10%); 2 (11 to 50%) and 3 (>50%). The mean value of the sum of the fields was the final score. Statistical differences among groups were investigated, considering p < 0.05.

RESULTS

ALDH1 expression in epithelium was low in all groups without difference among them. ALDH1+ cells in the lamina propria were higher for Lichen Planus [2.0], followed by Leukoplakia [1.3], Lichenoid lesions [1.2] and control [1.1] (p<0.05).

CONCLUSIONS

ALDH1 immunoexpression in epithelium of lichenoid potential malignant disorders did not show a contributory tool, however ALDH1 in stromal cells of lichen planus might be involved in the complex process of immune regulation associated with the pathogenesis of this disease.

Metastases of OSCC Based on Oral Lichen Ruber Planus

Oral lichen ruber planus (OLP) is a poorly understood chronically inflammatory disease of the oral mucosa. Malignant transformation into oral squamous cell carcinoma (OSCC) is reported in between 1-2% of cases in the literature. After malignant transformation, surgical treatment-meaning tumor resection combined with neck dissection-is recommended. The recommended extent of treatment is controversial in the literature because this kind of OSCC is often a highly differentiated tumor with a lower risk for lymph nodal spreading. This study aims to overview 103 patients treated in our department due to OLP. The primary outcome parameter was the development of metastases in OLP patients compared to a group of OSCC patients without OLP and the comparison of survival in between both groups. Statistical analysis showed a significantly lower risk for patients with OSCC and with OLP for lymph nodal spreading (p = 0.013). Patients with OSCC and without OLP had a 4.76-higher risk for lymph nodal spreading. On the other hand, second metachronous tumor occurred more often in patients with OSCC and OLP. Overall, OSCC based on OLP occurs more often in female patients, is more highly differentiated and comes with a lower risk for metastases but has a higher risk for second metachronous tumors. Therefore, special attention should be paid to patients with OSCC based on OLP when planning adjuvant therapy and clinical follow-up. The indication for postoperative radiation should be made cautiously in this case, and clinical controls should be performed more closely due to the risk of recurrent disease or tumors at different locations.

A digital score of peri-epithelial lymphocytic activity predicts malignant transformation in oral epithelial dysplasia

Oral squamous cell carcinoma (OSCC) is amongst the most common cancers, with more than 377,000 new cases worldwide each year. OSCC prognosis remains poor, related to cancer presentation at a late stage, indicating the need for early detection to improve patient prognosis. OSCC is often preceded by a premalignant state known as oral epithelial dysplasia (OED), which is diagnosed and graded using subjective histological criteria leading to variability and prognostic unreliability. In this work, we propose a deep learning approach for the development of prognostic models for malignant transformation and their association with clinical outcomes in histology whole slide images (WSIs) of OED tissue sections. We train a weakly supervised method on OED cases (n = 137) with malignant transformation (n = 50) and mean malignant transformation time of 6.51 years (±5.35 SD). Stratified five-fold cross-validation achieved an average area under the receiver-operator characteristic curve (AUROC) of 0.78 for predicting malignant transformation in OED. Hotspot analysis revealed various features of nuclei in the epithelium and peri-epithelial tissue to be significant prognostic factors for malignant transformation, including the count of peri-epithelial lymphocytes (PELs) (p < 0.05), epithelial layer nuclei count (NC) (p < 0.05), and basal layer NC (p < 0.05). Progression-free survival (PFS) using the epithelial layer NC (p < 0.05, C-index = 0.73), basal layer NC (p < 0.05, C-index = 0.70), and PELs count (p < 0.05, C-index = 0.73) all showed association of these features with a high risk of malignant transformation in our univariate analysis. Our work shows the application of deep learning for the prognostication and prediction of PFS of OED for the first time and offers potential to aid patient management. Further evaluation and testing on multi-centre data is required for validation and translation to clinical practice. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Cathepsins in oral diseases: mechanisms and therapeutic implications

Cathepsins are a type of lysosomal globulin hydrolase and are crucial for many physiological processes, including the resorption of bone matrix, innate immunity, apoptosis, proliferation, metastasis, autophagy, and angiogenesis. Findings regarding their functions in human physiological processes and disorders have drawn extensive attention. In this review, we will focus on the relationship between cathepsins and oral diseases. We highlight the structural and functional properties of cathepsins related to oral diseases, as well as the regulatory mechanisms in tissue and cells and their therapeutic uses. Elucidating the associated mechanism between cathepsins and oral diseases is thought to be a promising strategy for the treatment of oral diseases and may be a starting point for further studies at the molecular level.

The association between high-risk human papillomavirus and oral lichen planus

OBJECTIVES

Oral lichen planus (OLP) is a cell-mediated inflammatory mucosal disorder and is classified as an oral potentially malignant disorder. Some research has shown that apoptosis in OLP cells is similar to a viral infection such as human papillomavirus (HPV). So, the aim of this case-control study was to investigate the association of high-risk HPV with OLP.

MATERIAL AND METHODS

DNA was extracted from 25 formalin-fixed, paraffin-embedded (FFPE) OLP tissues and 25 FFPE normal oral tissues as case and control groups, respectively. The presence of high-risk HPV16 and HPV18 DNA was investigated by polymerase chain reaction (PCR). p-value<.05 was considered significant.

RESULTS

Twelve samples (48%) of OLPs were positive for HPV16, compared with six samples (24%) of controls; although the difference was not significant, it was borderline (p = .07). Three samples (12%) of OLPs were positive for HPV18 compared with one sample (4%) of controls; the difference was not significant (p = .3). The total frequency of both high-risk HPV were 14 samples (56%) of OLPs and 7 samples (28%) of controls; there was a significant association between the high-risk HPV and OLP (p = .04). High-risk HPVs was more prevalent in erosive-atrophic (EA) form of OLP as compared to non-EA form, although the difference was not significant (p = .13).

CONCLUSIONS

The results suggest a significant association between high-risk HPVs and OLP.

Oral Squamous Cell Carcinomas Developing from Oral Lichen Planus: A 5-21 year Retrospective Study

Background and Aims

There is insufficient data regarding clinical characteristics, relapse rates, as well as lymph node metastasis of squamous cell carcinomas of the oral cavity (OSCC) developing from oral lichen planus (OLP-OSCC). The aim of this retrospective study was to evaluate clinical characteristics, as well as relapse, recurrence and survival rates of OLP-OSCC.

Methods

In a retrospective monocenter analysis, all consecutive patients with an OSCC treated in the time period 1st January 2000-December 31 2016 were reviewed. All patients with OSCC developing from OLP/OLL (oral lichenoid lesions) were identified and analyzed for epidemiological data, risk profile, location of primary tumor, pTNM classification, lymph node metastasis, primary therapy, recurrence, and outcome.

Results

A total of 103 patients (45%♂/ 55%♀) with an average age of 62 ± 14 year were included in this study. At the time of initial diagnosis, 17% (n = 18) of patients had cervical metastases (CM) whereas only 11% (11 patients) displayed advanced tumor sizes (T > 2). T-status (p = 0.003) and histopathological grading (p = 0.001) had an impact on the incidence of CM. 39.6% of the patients developed a relapse after an average of 24 months with a mean of two recurrences per patient. Advanced tumor size had a significant impact on the 5 year overall survival and was associated with disease-free survival of the patients (p < 0.001, respectively p = 0.004).

Conclusion

Although initial lymph node metastases were not more frequent, more aggressive recurrence patterns compared to OSCC were seen for OLP-OSCC. Therefore, based on the study results, a modified recall for these patients is suggested.

Outcome and long-term treatment protocol for topical tacrolimus in oral lichen planus

BACKGROUND AND OBJECTIVE

Topical tacrolimus has been shown to be beneficial in the treatment of oral lichen planus (OLP). However, long-term effects and its optimal application protocol with gradual reduction have not been studied. Accordingly, we analysed the clinical response of OLP to tacrolimus in our daily clinical practice with a focus on the optimal long-term therapeutic scheme.

METHODS

Retrospective analysis of all consecutive patients diagnosed with OLP and treated with topical tacrolimus (0.03% oral rinse) in a clinical setting between 2015 and 2020. The objective clinical response was measured by a 4-point scale (complete remission, major remission, partial remission and no response), and subjective impairment by a 3-point scale (severe, moderate and none).

RESULTS

Fifty-seven patients (74% women; median age: 66 years) were included. Fifty-six (98%) patients had prior treatment with topical steroids. After introduction of tacrolimus, objective remission (major or complete) was reached by 28%, 62%, 87% and 97% of patients after 3, 6, 12 and 24 months respectively. Subjective remission was reported by 16%, 48%, 69% and 83% after 3, 6, 12 and 24 months of treatment respectively. The treatment frequency could be gradually reduced from initially twice daily to once daily or less in 28%, 61%, 78% and 87% after 3, 6, 12 and 24 months respectively; 41% of patients completely suspended the treatment at one point, but 67% of them experienced a relapse after a median time of 3.3 months. Four patients (7%) developed a squamous cell carcinoma (SCC) during the observation period. Otherwise, there were only few and minor side-effects.

CONCLUSION

Topical tacrolimus can be an effective second-line therapy for OLP refractory to potent topical corticosteroids. The therapy frequency can often be reduced during the maintenance period. Both signs of clinical activity and subjective impairment should guide therapy. Regular follow-up is necessary to recognize possible SCC.

The genomic and proteomic landscape in oral lichen planus versus oral squamous cell carcinoma: a scoping review

BACKGROUND

Oral lichen planus (OLP), a World Health Organization (WHO)-classified oral potentially malignant condition, confers a 1% risk of transformation to oral squamous cell carcinoma (OSCC). There does not appear to be a consensus understanding of the underlying molecular events. This scoping review aimed to identify critical molecular pathways and highlight gaps in existing knowledge on malignant transformation in OLP.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) guidelines, a comprehensive literature search and methodical screening identified 61 relevant studies detailing molecular differences between OLP and OSCC.

RESULTS

Molecular changes shared between OLP and OSCC included those affecting cellular proliferation (altered p53 expression, hypermethylation of p16/CDKN2A, MYC gains, increased ki-67), apoptosis (increased bcl-2 and survivin expression), extracellular matrix (ECM) remodeling (increased matrix metalloproteinase [MMP] expression), and transcriptional control (altered bmi1 and microRNA [miRNA] expression). In addition, some molecular alterations accumulated incrementally from control to OLP to OSCC or were present in higher-risk erosive variants of OLP or transformed OLP. Few studies included rigorous diagnostic inclusion criteria or unbiased discovery methods.

CONCLUSIONS

Results of this review support the potentially malignant nature of OLP and imply that molecular events associated with malignant transformation may be heterogeneous. In addition, findings in this review highlight the need for additional studies using rigorous diagnostic inclusion criteria and unbiased discovery methods to further understand this process.

Cathepsin-B and caveolin-1 gene expressions in oral lichen planus and oral squamous cell carcinoma

BACKGROUND

Given the importance of the role of cellular changes in the prognosis and diagnosis of malignancies of the head and neck, we examined in this study the gene expressions of cathepsin-B (Cat-B) and caveolin-1 (Cav-1) which are in cell membranes structures involved in carcinogenesis, in oral squamous cell carcinoma (OSCC) and oral lichen planus (OLP) and compared them to controls. We also investigated their relationship to clinicopathological indices.

METHODS AND RESULTS

In this case-control study, 29 paraffin blocks of OLP patients were compared to 29 paraffin blocks of OSCC samples as well as 28 paraffin blocks of normal oral tissue. Real-time quantitative PCR was performed to determine gene expressions and results were analyzed for their relationship to clinical data using chi-square, Kruskal-Wallis and Mann-Whitney tests.

RESULTS

The mean age of OSCC and OLP patients were 59.24 ± 15.04 and 48.79 ± 14.17 years, respectively. The Cat-B and Cav-1 expressions were significantly higher in OSCC and OLP samples compared to control (p < 0.001). The highest expression was found in OSCC samples. The difference between OLP and control samples for Cat-B and Cav-1 expression was significant. There was no association between the gene expression and age, gender, duration of disease, Thongprasom score, smoking and cutaneous lichen planus. However, the expressions were related to the grade and stage of OSCC samples (P = 0.01, P = 0.02).

CONCLUSION

The gene expressions of Cat-B and Cav-1 in OSCC were associated with the stage and grade of lesions. Therefore, they appear to be useful in predicting the biological behavior of OSCC and malignant transformation of OLP, although this process is multi factorial and more investigations are needed.

Immunohistochemical Evaluation of Transforming Growth Factor-β Expression in Oral Lichen Planus

Background: In oral lichen planus (OLP), which is a persistent inflammatory condition of the autoimmune system, cytotoxic T lymphocytes are triggered against epithelial cells. OLP resists treatment more than its cutaneous counterpart and potentially transforms into malignancy as oral squamous cell carcinoma (OSCC). Transforming growth factor β (TGF-β) is produced by various cells, such as leukocytes and epithelial cells, whereby epithelial-mesenchymal-epithelialn (EMT) forms the phenotype of invasive cancerous cells and promotes tumors. Objectives: We investigated the role of TGF-β in the pathogenesis and biological behavior of dysplastic and non-dysplastic OLP. Methods: Thirty samples of erosive/atrophic OLP (15 dysplastic and 15 non-dysplastic) and 10 samples of normal mucosa of the oral cavity were immunohistochemically examined for the expression of TGF-β. Statistical analysis was performed using the Kruskal-Wallis and chi-squared tests. Results: TGF-β expressed to varying degrees in the epithelium of the studied groups. The groups significantly differed in terms of the expression of TGF-β. In pairwise comparisons, the dysplastic OLP group showed significantly higher immunoreactivity than the normal and non-dysplastic groups, although there was no significant difference between the normal and non-dysplastic OLP groups. The expression of TGF-β in the sub-epithelial lymphocytes of the dysplastic and non-dysplastic OLP groups showed a statistically significant difference. Conclusions: According to the results, TGF-β, as a marker of the inflammatory process in chronic inflammatory conditions, was expressed in epithelial cells and sub-epithelial lymphocytes of all OLPs. This suggests a possible role of this marker in the pathogenesis of OLP. In addition, the increased expression of TGF-β, a marker also involved in carcinogenesis, in the epithelial keratinocytes indicates the role it might play in the development of carcinoma in OLP.

Influence of topical corticosteroids on malignant transformation of oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is considered an oral potentially malignant disorder. While OLP has been associated with the development of oral squamous cell carcinoma (OSCC), little is known about the role of topical corticosteroids therapy (TCT) in the promotion of carcinogenesis. The study aimed to determine if TCT influences the time of malignant transformation of OLP to OSCC. The study also investigates this correlation in the presence or absence of Candida overgrowth, and in the context of conventional OSCC risk factors such as smoking, alcohol use, and male gender.

METHODS

A retrospective analysis of electronic health records at a tertiary care academic medical center was performed. Patients with OLP and OSCC were considered for inclusion. The diagnosis of OLP required both clinical and histological documentation.

RESULTS

Eighty-two patients met inclusion criteria, consisting of 48 women (58.25%) and 34 men (41.5%) and the mean patient age was 65.9 years (SD = 13.25). Forty-five patients (54.9%) received TCT for OLP before they developed OSCC. The time between the OLP and OSCC diagnoses increased by four years in patients who received topical steroid therapy for OLP (p < 0.001) and decreased by three years (p = 0.010) in those with Candida overgrowth. Gender, smoking, and alcohol use did not have a statistically significant influence on the time between OLP and OSCC.

CONCLUSION

The management of OLP using TCT potentially delayed cancer development in our study. Conversely, it appears that Candida may play a role in the field cancerization of OLP patients.

Expression profile of DNA repair proteins and histone H3 lys-9 acetylation in cutaneous and oral lichen planus

OBJECTIVES

To analyze the expression profile of DNA repair proteins (XRCC1 and APE1) and histone acetylation (H3K9) in oral and cutaneous lichen planus, in order to investigate potential biological markers that can clarify pathogenesis of these lesions.

DESIGN AND RESULTS

The total sample consisted of 89 lichen planus cases (66 oral and 23 cutaneous). Analysis of APE1 and XRCC1 expression was performed by immunohistochemistry in 44 oral and 20 cutaneous lichen planus, whereas the analysis of H3K9 acetylation was performed by immunofluorescence in 42 oral and 11 cutaneous lichen planus.

RESULTS

Immunoreactivity for APE1 and XRCC1 was significantly higher in cutaneous lichen planus than in oral lichen planus (P = 0.003 and P = 0.034, respectively). There was a significant and moderate positive correlation between APE1 and XRCC1 in the oral group (Rho = 0.544; P < 0.0001). In oral cases, there were no statistically significant results comparing APE1 and XRCC1 expression between reticular and erosive cases (P > 0.05). Evaluation of H9K3 histone acetylation levels did not reveal significant results comparing oral to cutaneous lichen planus, neither comparing erosive to reticular (P > 0.05).

CONCLUSIONS

Changes in the expression profile of the DNA repair proteins exerted greater influence in pathogenesis of cutaneous lichen planus than oral lichen planus, in addition, H3K9 histone acetylation is an epigenetic event found in both lesions.

The expression of Cathepsin L in oral lichen planus

Background

Malignant transformation of oral lichen planus (OLP) was reported particularly in erosive type, however, it remains inconclusive. Cathepsin L was shown to promote tumor growth and invasion in many cancers. Therefore, cathepsin L expression in erosive and non-erosive OLP compared with oral epithelial dysplasia and oral squamous cell carcinoma (OSCC) were investigated.

Methods

Thirty specimens of OLP (15 cases each of erosive and non-erosive OLP), 10 cases of oral epithelial dysplasia and 10 cases of OSCC were included. Ten healthy gingiva specimens were served as controls. All specimens were stained with cathepsin L antibody using immunohistochemistry technique.

Results

Cathepsin L was expressed in all OLP and OSCC cases. In oral epithelial dysplasia and healthy gingiva, the expression was found at 90% and 50% respectively. The percentage of positive cells was the highest in erosive OLP (27.26 ± 12.09%), followed by non-erosive OLP (20.85 ± 7.43%), OSCC (20.15 ± 15.70%), oral epithelial dysplasia (9.24 ± 7.00%) and healthy gingiva (2.27 ± 5.65%). Most of non-erosive OLP cases showed mild staining intensity while erosive OLP and OSCC showed moderate staining intensity. Cathepsin L was mainly expressed at basement membrane zone and inflammatory cells of OLP. In OSCC, the expression was found in tumor islands and keratin pearls. In oral epithelial dysplasia and normal gingiva, cathepsin L expressions were low and presented in scattered pattern in both epithelium and connective tissue.

Conclusion

According to the patterns of expression in this study, cathepsin L could be implicated in pathogenesis and severity of OLP.

Urinary metabolomic signatures in reticular oral lichen planus

Oral lichen planus (OLP) is a chronic inflammatory disease. Among all the clinical forms in OLP, reticular type has the highest incidence rate. Previous studies have applied metabolomics to investigate the metabolic changes of oral mucosa and blood samples from reticular OLP patients. Urinary metabolomic signatures is also useful in analyzing the pathological changes of the patients, which was a complement to the previous studies. Through these researches, we may have a more comprehensive understanding of the disease. Metabolic profiles of urinary samples from OLP patients and control subjects were analyzed by liquid chromatography (LC)-mass spectrometry (MS) system. Differentially expressed metabolites were identified via OSI/SMMS software for the pathology analysis. Totally, 30 differentially expressed metabolites were identified. Pathological network showed that these metabolites participated in 8 pathological processes, that is, DNA damage and repair disorder, apoptosis process, inflammatory lesion, oxidative stress injury, carbohydrate metabolism disorder, mood dysfunction, abnormal energy expenditure, and other pathological process. These findings demonstrated that the analysis of human urine metabolome might be conducive to the achievement of the objectives of this study.

Single Nucleotide Polymorphisms in 25-Hydroxyvitamin D3 1-Alpha-Hydroxylase (CYP27B1) Gene: The Risk of Malignant Tumors and Other Chronic Diseases

: Vitamin D is widely known for its roles in the promotion of apoptosis and differentiation, with simultaneous inhibition of proliferation, inflammation, angiogenesis, invasion, and metastasis. Modern literature lacks complete information on polymorphisms in CYP27B1, the only enzyme capable of vitamin D activation. This review presents gathered data that relate to genetic variants in CYP27B1 gene in correlation to multiple diseases, mostly concerning colorectal, prostate, breast, lung, and pancreatic cancers, as well as on other pathologies, such as non-Hodgkin's lymphoma, oral lichen planus, or multiple sclerosis.

Vitamin D receptor genetic polymorphisms are associated with oral lichen planus susceptibility in a Chinese Han population

BACKGROUND

Vitamin D receptor (VDR) is involved in multiple immune-mediated disorders including oral lichen planus (OLP). This study investigated the association between VDR gene polymorphisms and the risk of OLP.

METHODS

In total, 177 OLP patients and 207 healthy participants were recruited from the Affiliated Hospital of Stomatology, Nanjing Medical University. Eight single nucleotide polymorphisms (SNPs: rs731236, rs739837, rs757343, rs2107301, rs2239185, rs7975232, rs11574129 and rs11568820) in the VDR gene were selected and genotyped.

RESULTS

The results showed that OLP risk was increased in subjects with the rs2239185 TT genotype (Recessive model: adjusted Odd ratio(OR) = 2.68, 95% Confidence interval(CI) = 1.28-5.62, P = 0.009) and rs7975232 CC genotype (Recessive model: adjusted OR = 2.25, 95% CI = 1.10-4.58, P = 0.026). Moreover, rs2239185 and rs7975232 (P < 0.01) showed significant cumulative effects on OLP risk.Haplotype analysis showed that the CC haplotype (rs2239185-rs7975232) was associated with an increased risk of OLP (OR = 3.11, 95% CI = 1.42-6.83, P = 0.005), compared with the AC haplotype.

CONCLUSION

The rs2239185 and rs7975232 variants of VDR may influence OLP susceptibility, and VDR gene polymorphisms may be candidate susceptibility regions for OLP in a Chinese Han population.

Intraoral Ultra-High Frequency Ultrasound study of oral lichen planus: A pictorial review

BACKGROUND

Ultra-High Frequency Ultrasound (UHFUS) is a recently introduced diagnostic technique involving the use of higher frequencies compared to conventional ultrasound. Among the several fields of application, intraoral usage of UHFUS appears still limited. We report the intraoral evaluation of Oral Lichen Planus (OLP) by means of UHFUS and describe typical UHFUS aspect of different forms of presentation of OLP.

MATERIALS AND METHODS

Patients with clinical and histological diagnosis of OLP were enrolled in the study. OLP lesions were evaluated by means of intraoral UHFUS performed at 70 MHz, using B-mode and C-mode, in order to characterize the echostructure of each form of presentation.

RESULTS

Fifty patients in total were enrolled, and UHFUS features were described for different OLP forms. All the lesions showed a thick, hypoechoic superficial layer in the mucosal stratum, suggesting that such UHFUS alteration can be pathognomonic of OLP.

CONCLUSION

Ultra-High Frequency Ultrasound was able to differentiate superficial alterations of the oral mucosa, giving insight on possible applications of UHFUS in the study of OLP beyond clinical and histological investigations. Due to a limited study sample, we cannot draw firm conclusions. However, it is reasonable to think that UHFUS evaluation of OLP may provide useful information to the clinician.

Role of mammary serine protease inhibitor on the inflammatory response in oral lichen planus

OBJECTIVES

Oral lichen planus (OLP) is a chronic inflammatory condition with an unclear pathological mechanism. IκB kinase α (IKKα)-regulated mammary serine protease inhibitor (MASPIN) has been shown to mediate inflammation, particularly in cancers. Here, we explored the expression of MASPIN in OLP and its role in the inflammatory response.

MATERIALS AND METHODS

Immunohistochemistry staining and reverse transcription-polymerase chain reaction assays were used to detect the subcellular localization and expression of MASPIN and IKKα in OLP and healthy control tissues. Levels of the inflammatory factors were compared with enzyme-linked immunosorbent assays. MASPIN and IKKα were overexpressed and silenced, respectively, in an inflammation model of human oral keratinocytes (HOKs) stimulated with lipopolysaccharide (LPS).

RESULTS

Mammary serine protease inhibitor expression was down-regulated, whereas IKKα expression was up-regulated in OLP tissues (p < 0.01). The levels of tumour necrosis factor-alpha and interleukin-6 in OLP tissues were increased compared to those of healthy controls (p < 0.01). MASPIN overexpression in LPS-stimulated HOK cells inhibited the levels of IKKα and the secretion of inflammatory cytokines. By contrast, IKKα silencing promoted the expression of MASPIN and inhibited the secretion of inflammatory cytokines.

CONCLUSION

Both MASPIN and IKKα are involved in the inflammatory process of OLP, suggesting potential therapeutic targets.

Serum-based metabolomics characterization of patients with reticular oral lichen planus

OBJECTIVE

Oral lichen planus (OLP) is a chronic inflammatory mucosal lesion and systemic disease. In OLP, reticular type is the most common presentation of the disease. However, little is known about it. The aim of this study was to analyze the pathogenesis of reticular OLP and its possible associations with the pathological changes in other organ systems through serum-based metabolomics.

METHODS

Blood samples were obtained from 16 reticular OLP patients and 24 control subjects. Liquid chromatography (LC)-mass spectrometry (MS) system was used to identify differentially expressed metabolites. The pathways analysis was performed by MetaboAnalyst. Pathological network was constructed by Cytoscape software.

RESULTS

Totally, 31 modulated metabolites were identified, whose dysregulations affected 25 metabolic pathways and 7 pathological processes in the disease. Through an impact-value screen (impact-value＞0.1), 6 pathways were selected as the significantly dysregulated pathways. Pathological network showed that these metabolites participated in 7 pathological processes, that is, apoptosis process, DNA damage and repair disorder, oxidative stress injury, carbohydrate metabolism disorder, mood dysfunction, inflammatory lesion, and other pathological process.

CONCLUSION

The study demonstrated that reticular OLP could cause the dysregulations of the metabolites in serum, which might be also further linked to other organ and systemic diseases through the blood system, such as diabetes, sleep disorders, and depression, etc.

Role of miR-155 in immune regulation and its relevance in oral lichen planus

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.

Oral lichenoid lesions of the upper lip and gingiva: What we know so far

The clinical presentation of oral lichen planus and oral lichenoid lesions is diverse. A special category of patients presents with lichenoid lesions affecting only the mucosa of their upper lip and the anterior upper gingiva. This is a concise review summarizing the specific characteristics of these patients.

Chicken or the Egg: Microbial Alterations in Biopsy Samples of Patients with Oral Potentially Malignant Disorders

Oral carcinogenesis often leads to the alteration of the microbiota at the site of the tumor, but data are scarce regarding the microbial communities of oral potentially malignant disorders (OPMDs). Punch biopsies were taken from healthy and non-healthy mucosa of OPMD patients to analyze the microbiome using metagenome sequencing. In healthy oral mucosa biopsies the bacterial phyla Firmicutes, Fusobacteria, Proteobacteria, Actinobacteria and Bacteroidetes were detected by Ion Torrent sequencing. The same phyla as well as the phyla Fibrobacteres and Spirochaetes were present in the OPMD biopsies. On the species level, there were 10 bacterial species unique to the healthy tissue and 35 species unique to the OPMD lesions whereas eight species were detected in both samples. We observed that the relative abundance of Streptococcus mitis decreased in the OPMD lesions compared to the uninvolved tissue. In contrast, the relative abundance of Fusobacterium nucleatum, implicated in carcinogenesis, was elevated in OPMD. We detected markedly increased bacterial diversity in the OPMD lesions compared to the healthy oral mucosa. The ratio of S. mitis and F. nucleatum are characteristically altered in the OPMD lesions compared to the healthy mucosa.

Rate of malignant transformation of oral lichen planus: A systematic review

OBJECTIVE

The aim of this study was to systematically review the literature to determine: (a) the malignant transformation rate (TR) of oral lichen planus (OLP) and its risk factors; (b) whether or not oral lichenoid lesions (OLL) have a different malignant TR.

MATERIALS AND METHODS

PubMed, Scopus, and Web of Science were used as search engines: only observational, full-length, English language studies were investigated. PRISMA protocol was used to evaluate and present results. PROSPERO registration code is CRD42016048529.

RESULTS

Among 7,429 records screened, only 21 were included in this review. Ninety-two of 6,559 patients developed oral squamous cell carcinoma, with an overall TR of 1.40% (1.37% for OLP and 2.43% for OLL), an annual TR of 0.20%. Female gender, red clinical forms, and tongue site seem to slightly increase the transformation risk.

CONCLUSIONS

This systematic review confirms that both OLP and OLL, the latter with a slightly higher TR, may be considered potentially malignant disorders and suggest that erosive type, female gender and tongue site should be considered as risk factors for OLP transformation. Major efforts should be done to establish strict clinical and histological criteria to diagnose OLP and to perform sounder methodological observational studies.

Immunohistochemical Study of p53 Expression in Patients with Erosive and Non-Erosive Oral Lichen Planus

STATEMENT OF THE PROBLEM

Oral lichen planus is a common mucocutaneous lesion with a chronic inflammatory process mediated by immune factors while a few cases of the disease become malignant.

PURPOSE

This study aimed to determine the frequency of p53 marker as a tumor suppressor in patients with erosive and non-erosive oral lichen planus (OLP) by using immunohistochemical methods.

MATERIALS AND METHOD

This descriptive cross-sectional study investigated the p53 expression in 16 erosive OLP, 16 non-erosive OLP samples, and 8 samples of normal oral mucosa through immunohistochemistry. The percentage of stained cells in basal and suprabasal layers, and inflammatory infiltrate were graded according to the degree of staining; if 0%, <10%, 10-25%, and >50% of the cells were stained, they were considered as (-), (+), (++), (+++) and (++++), respectively. The obtained data was statistically analyzed and compared by using Chi square and Fisher's exact test.

RESULTS

The mean percentage of p53 positive cells in erosive OLP (34.5±14.2) was considerably higher than that in non-erosive OLP (23.8±10.4) and normal mucosa (17.5±17). There was a significant difference among the three groups of erosive, non-erosive and control in terms of staining intensity. No significant difference existed between the patients' age and sex in the two OLP groups.

CONCLUSION

The increased incidence of p53 from normal mucosa to erosive OLP indicated the difference between biological behavior of erosive and non-erosive OLP. It can be claimed that the erosive OLP has great premalignant potential compared with the non-erosive one.

Risk factors and etiopathogenesis of potentially premalignant oral epithelial lesions

Potentially malignant oral mucosal disease has some ability to give rise to malignancy of the oral epithelium, that is, oral squamous cell carcinoma (OSCC). The present article provides a succinct review of the possible or probable causes of potentially premalignant oral epithelial lesions. There is a focus upon studies that examined the causes or etiologic associations with clinically likely or histopathologically detectable oral epithelial dysplasia.

Role of Cathepsin B as a Marker of Malignant Transformation in Oral Lichen Planus: An Immunohistochemical Study

INTRODUCTION

Malignant transformation of Oral Lichen Planus (OLP) remains a much discussed but very less understood realm. Various hypotheses and theories have been put forward to explain the same. Malignant transformation is a complex interplay of epithelial mesenchymal factors acting in tandem. This study tries to identify and asses the stromal changes that pave the way for epithelial migration using Cathepsin B (CB) a cysteine protease belonging to the Cathepsin family. Various studies have been done to study its role in human cancers which have proven that CB helps mark and identify tissue digestion.

AIM

The purpose of this study was to evaluate the expression of CB, in OLP and examine its possible role in malignant transformation.

MATERIALS AND METHODS

Immunohistochemical analysis of CB expression was done in 50 OLP tissues along with 10 normal mucosa tissue and 10 Oral Squamous Cell Carcinoma (OSCC) cases (control groups). Evaluation was done on the basis of intensity of staining. The intensity was graded in all the cases by assigning values of 0 to 4 in ascending order. Two other observers evaluated the staining and intensity independently and the average of the observations was taken.

RESULTS

A variable staining pattern in both the stroma and the cytoplasm of the epithelial cells was noticed. The staining intensity was clearly increased in OLP tissues when compared to normal control tissue and OSCC which served as our positive control. The staining patterns in tissues of OLP and OSCC to Cathepsin B were similar. The staining intensity of Cathepsin B was observed to be increased in both these groups of tissues.

CONCLUSION

This study demonstrated a significantly increased expression of CB in OLP. This may be correlated to a possible indicator for its eventual malignant transformation. This overexpression of CB amounts to an array of stromal changes that take place and different mechanisms that get activated underneath the epithelium leading to the formation of what is known as a tumour microenvironment, a well proven entity. We hypothesize that it is this which felicitates the invasion of the overlying epithelial cells.

The cellular character of liquefaction degeneration in oral lichen planus and the role of interferon gamma

BACKGROUND

Oral lichen planus (OLP) is a T-cell-mediated chronic inflammatory oral mucosal disease of unknown etiology, and liquefaction degeneration in the basal keratinocytes is one of the specific histological changes. However, the understanding of liquefaction degeneration is still very limited, and how does it affect the prognosis of LP is largely unknown. Therefore, the objective of this study was to clarify the intrinsic change behind the liquefaction degeneration in lichen planus and to evaluate the effect of the OLP-typical cytokine, IFN-γ, on these changes.

MATERIALS AND METHODS

Biopsies were collected from patients with OLP; immunochemistry staining was performed to analyze E-cadherin, vimentin, CK19, β1 integrin, nestin, STAT1, and STAT3 expression. Primary oral epithelial cells were cultured in vitro, and 20 ng/mL IFN-γ was applied to assay the effect on epithelial cells.

RESULTS

E-cadherin expression was decreased but vimentin expression was increased in the OLP epithelial cells that undergo liquefaction degeneration, showing the typical epithelial-mesenchymal transition (EMT) alteration. In vitro research showed that the OLP-typical cytokine, IFN-γ, possesses EMT-inducing ability, and the primary oral epithelial cells stimulated by IFN-γ acquired some properties of cancer stem cells, expressing more β1 integrin, α6 integrin, and nestin. In addition, the major downstream mediator of IFN-γ receptor, STAT1, was expressed more intensive and extensive with the malignant transition of OLP.

CONCLUSION

Liquefaction degeneration in oral lichen planus is an EMT phenomenon, the IFN-γ may be the main inducer, and IFN-γ signaling might be implicated in malignant transition of OLP.

Increased salivary aldehyde dehydrogenase 1 in non-reticular oral lichen planus

Background

Oral lichen planus is a potentially malignant disorder. One of the malignant transformation markers is cancer stem cells. One of the proposed marker for the detection of cancer stem cells's in head and neck cancer is aldehyde dehydrogenase. Recently it is shown that aldehyde dehydrogenase 1 expression in tissue samples is associated with oral lichen planus malignant transformation.

Objective

This study evaluates salivary aldehyde dehydrogenase 1 in oral lichen planus.

Method

Thirty patients and 30 age and sex-matched healthy volunteers were recruited. Oral lichen planus was diagnosed based on the modified World Health Organization criteria. Subjects in the case group were divided into reticular and non-reticular forms. Unstimulated salivary samples were collected at 10-12 AM. Saliva concentrations of aldehyde dehydrogenase 1 were measured by ELISA.

Results

The differences between aldehyde dehydrogenase levels in the oral lichen planus group compared with the control group were not significant but aldehyde dehydrogenase in non-reticular oral lichen planus was significantly higher than that of the reticular form.

Limitations of the study

This is a cross-sectional study, thus longitudinal studies in oral lichen planus may present similar or different results.

Conclusions

The mechanism of malignant transformation in oral lichen planus is not defined. Previous analyses revealed that the aldehyde dehydrogenase 1 expression is significantly correlated with increased risk of transformation. This finding is consistent with our results because in the erosive and ulcerative forms of oral lichen planus, which have an increased risk of transformation, salivary aldehyde dehydrogenase 1 was overexpressed. A higher salivary aldehyde dehydrogenase level in non-reticular oral lichen planus can be a defensive mechanism against higher oxidative stress in these groups. Aldehyde dehydrogenase may be one of the malignant transformation markers in oral lichen planus. Further studies are needed for introducing aldehyde dehydrogenase as a prognostic indicator in certain lesions.

Study of the TP53 codon 72 polymorphism in oral cancer and oral potentially malignant disorders in Argentine patients

The aim of this work was to evaluate the prevalence of TP53Arg72Pro mutations and their possible relationship with oral carcinoma and oral potentially malignant disorders in Argentine patients. A cross-sectional study was performed on 111 exfoliated cytologies from patients with oral cancer (OC), oral potentially malignant disorders (OPMD) and controls. The TP53Arg72Pro mutations were determined using conventional PCR. We evaluated univariate and multivariate study variables, setting p < 0.05. We found: (a) a low frequency of Pro72 variant in control group and a high frequency in OC and OPMD, as well in OC and oral leukoplakia (OL) diagnosis; (b) multivariate association among the TP53CC genotype and females over 45 years with no tobacco nor alcohol habits with oral lichen planus pathology; (c) multivariate association between the TP53GC genotype and males with alcohol and tobacco habits and OC and OL pathologies. Our results showed that the wild-type Arg72variant was related to control patients and Pro72variant was related to OC and OPMD, in Argentine patients.

Oral lichenoid lesions of the upper lip

BACKGROUND

Oral lichen planus is a chronic inflammatory disease of unknown etiology. It is characterized by notable heterogeneity in clinical presentation and behavior.

MAIN OBSERVATIONS

We describe 3 patients with lichenoid lesions of the upper lip and upper anterior gingiva. These cases probably represent a clinical subtype of lichenoid lesions associated with microbial antigenicity and are characterized by persistency. All three patients had a long history of previous ineffective treatments and all three showed an excellent response to a combination of clarithromycin (2 x 250 mg/day) and prednisolone (15 mg/day).

CONCLUSION

The combination of clarithromycin and prednisolone may be considered as an alternative intervention in patients with lichenoid lesions of the upper lip and upper anterior gingiva.

A Rare Case of Malignant Transformation of Oral Lichen Planus of the Mandible

Oral lichen planus (OLP) is an immune-mediated mucocutaneous disease associated with an increased risk in oral squamous cell carcinoma (OSCC). Nearly all cases of malignant transformation have been reported in patients >40 years old. We report the case of a 37-year-old woman with a 5-year history of erosive OLP who presented with malignant transformation to OSCC. Delineating the margins of the disease was impossible at presentation given her OLP, and she was initially treated with concurrent chemoradiation therapy. She then developed a recurrence of the mandibular alveolar ridge. The patient was successfully treated with a composite resection including a segmental mandibulectomy, buccal mucosa resection, partial glossectomy, and ipsilateral neck dissection. This was reconstructed with a free fibula osteo-septo-cutaneous flap. Mandibular OSCC is a rare complication of OLP with few reports on effective reconstructive interventions. The case represents the youngest reported patient with mandibular OSCC arising in the context of OLP and highlights the utility of the free vascularized fibula graft in the treatment of these patients.

Genomewide miRNA profiling of oral lichenoid disorders and oral squamous cell carcinoma

OBJECTIVE

To dissect the aberrant microRNA profile of oral lichenoid disorders (OLD) by analyzing the larger set of OLD samples tested so far.

MATERIALS AND METHODS

MicroRNA expression profiles were assessed using TLDA card in 32 samples (16 OLD, 8 OSCC, and 8 control). The findings were validated using RT-qPCR in an independent cohort of 91 samples.

RESULTS

We identified 20 differentially expressed microRNAs in OLD, of which several are functionally related to cell proliferation, response to organic substances, or immune processes. Further validation of the top-ranked microRNAs revealed that they were all aberrantly expressed in OLD.

CONCLUSION

We have identified a new microRNA signature associated with OLD that may provide a meaningful basis for better understanding the physiopathology of the disease. In addition, we validated seven microRNAs whose expression was shown to be higher in OLD tissue in comparison with the control and OSCC tissues.

Oral lichen planus

Lichen planus is an inflammatory mucocutaneous disease that can affect the skin, hair, nails, and mucosal surfaces. Mucosal sites of involvement include oral, genital, ocular, otic, esophageal, and, less commonly, bladder, nasal, laryngeal, and anal surfaces. Oral lichen planus is a mucosal variant of lichen planus, which tends to affect women more often than men, with a typically more chronic course and potential for significant morbidity. Treatment can be challenging, and there is potentially a low risk of malignant transformation; however, therapeutic benefits can be obtained with various topical and systemic medications. Clinical monitoring is recommended to ensure symptomatic control. Increasing awareness and recognition of this entity have continued to fuel advances in therapy and in our understanding of the disease.

A case-control study to detect the extent of DNA damage in oral lichen planus and oral lichenoid reactions using comet assay

Aim:

This study aims to quantify the extent of DNA damage in lymphocytes of patients with oral lichen planus (OLP) and oral lichenoid reactions (OLRs) using comet assay.

Methodology:

Lymphocytes from peripheral blood were subjected to alkaline comet assay. Comet length (CL), head diameter (HD), percentage of DNA in head, tail length (TL), percentage of DNA in tail, tail intensity, tail mean and tail moment were compared between study group (OLP and OLR) and control group using Student's t-test. Pearson's correlation coefficient was used to examine the linear association between the variables.

Results:

Significantly higher levels of DNA damage was present in study group as reflected by CL, HD and TL, tail intensity and tail moment with P = 0.0001; percentage of DNA in head and tail with P = 0.02 and tail mean with P = 0.012.

Conclusion:

This study brings out the fact that DNA damage measured by comet assay was greater in the study group when compared to the control group. As a reflection of uniqueness, this study crowns the scenario with respect to early detection and prevention of potentially malignant disorders and the process of malignant transformation.

Challenges in predicting which oral mucosal potentially malignant disease will progress to neoplasia

Probably the greatest challenge to those managing patients with oral diseases is the dilemma of attempting to predict which oral erythroplakias, leukoplakias, lichenoid and other potentially malignant mucosal disease (PMD) such as oral submucous fibrosis will progress to neoplasia--notably oral squamous cell carcinoma (OSCC). The paper reviews progress over the past decade and the application to the clinical situation.

Study of P21 Expression in Oral Lichen Planus and Oral Squamous Cell Carcinoma by Immunohistochemical Technique

STATEMENT OF THE PROBLEM

Lichen planus is a mucocutaneous disease that is relatively common in middle aged individuals. Some studies have shown that oral lichen planus has a potential to progress to squamous cell carcinoma.p21 is a cyclin-dependent kinase inhibitor that regulates the cell cycle, thus it acts as an inhibitor in cell proliferation.

PURPOSE

This study was aimed to evaluate and compare the immunostaining of p21 (as a proliferation inhibitory factor) in oral lichen planus (OLP) and oral squamous cell carcinoma (OSCC).

MATERIALS AND METHOD

In this descriptive cross-sectional study, p21expression was investigated in 24 samples of oral lichen planus (OLP), 24 samples of oral squamous cell carcinoma (OSCC) and 24 samples of oral epithelial hyperplasia (OEH) by employing immunohistochemical staining.

RESULTS

The mean percentage of p21-positive cells in OSCC (54.5±6.6) was significantly higher than that in OLP (32.8±6.08) and OEH (9.4±3.8). Moreover, OLP samples expressed p21 significantly higher than the OEH. Kruskal Wallis test revealed a statistically significant difference between the groups regarding the intensity of staining (p< 0.001).

CONCLUSION

According to the findings of this study, the expression of p21 might be related to the potential carcinogenic transformation of lichen planus to SCC. Therefore, continuous follow-up periods for OLP are recommended for diagnosis of the malignant transformations in early stages.

Association of vdr, cyp27b1, cyp24a1 and mthfr gene polymorphisms with oral lichen planus risk

OBJECTIVES

The current study investigated the association between VDR EcoRV (rs4516035), FokI (rs2228570), ApaI (rs7975232) and TaqI (rs731236), CYP27B1 (rs4646536), CYP24A1 (rs2296241), and MTHFR (rs1801133) gene polymorphisms and risk of oral lichen planus (OLP) occurrence.

MATERIALS AND METHODS

The study group consisted of 65 oral lichen planus patients and 100 healthy blood donors in the control group. Single nucleotide polymorphisms were genotyped by real time PCR or PCR-restriction fragment length polymorphism (RFLP) method.

RESULTS

Heterozygous as well as mutated genotype of vitamin D receptor (VDR) FokI (rs2228570) polymorphism was associated with increased oral lichen planus risk in comparison with wild type genotype (odds ratio (OR) = 3.877, p = 0.017, OR = 38.153, p = 0.001, respectively). A significantly decreased OLP risk was observed for heterozygous genotype of rs2296241 polymorphism in CYP24A1 gene compared with the wild type form (OR = 0.314, p = 0.012). VDR gene polymorphisms ApaI and TaqI were in linkage disequilibrium (D' = 0.71, r(2) = 0.22). Identified haplotype AT was associated with decreased OLP risk (OR = 0.592, p = 0.047).

CONCLUSION

Our results highlight the possible important role of VDR FokI (rs2228570) and CYP24A1 rs2296241 gene polymorphisms for oral lichen planus susceptibility.

CLINICAL RELEVANCE

Identification of new molecular biomarkers could potentially contribute to determination of individuals with OLP predisposition.

Active inflammatory biomarkers in oral lichen planus

Oral lichen planus (OLP) is a chronic disease, with a central role to cell-mediated autoimmunity. Osteopontin promotes migration and recruitment of immune cells, CD44 is its receptor, and Survivin seems to be important in skin/mucosa homeostasis. The aim of this study was to investigate their expression in biopsy specimens of patients with different OLP clinical types and healthy controls.Biopsy specimens from 30 patients with OLP (15 atrophic and 15 hyperplastic) and 15 healthy controls were subjected to immune-histochemical analysis, to detect the expression of osteopontin, CD44, and Survivin in oral epithelia. The distributions of positively stained cells were evaluated with a quantitative method, while the inflammation degree was evaluated with a semi-quantitative one.Expression of osteopontin and CD44 was higher in OLP than controls, while Survivin expression was lower in OLP patients. There was a greater reduction of Survivin expression in atrophic OLP than hyperplastic OLP. A correlation between osteopontin expression and a high degree of inflammation was found. Furthermore, Survivin expression was higher in cases with low intensity of inflammation.Osteopontin, CD44, and Survivin seem to be involved in OLP pathogenesis, and further investigations are needed for clarifying their role in this oral disease.