Oral submucous fibrosis: review on mechanisms of malignant transformation

OXIDATIVE STRESS AND ANTIOXIDANT MARKERS IN ORAL SUBMUCOUS FIBROSIS: A SYSTEMATIC REVIEW AND META-ANALYSIS OF CASE-CONTROL STUDIES

OBJECTIVE

This meta-analysis systematically investigates the markers of oxidative stress (OS) and antioxidant systems in the saliva and serum of patients with oral submucous fibrosis (OSF) and healthy controls.

METHODS

Using a comprehensive search of databases from their inception period to December 31, 2023, articles related to OS or antioxidant markers in patients with OSF and healthy controls were retrieved. Literature screening and data extraction were performed by two reviewers according to the set criteria, and a third evaluator was involved in case of disagreements. The included studies were assessed with the Newcastle-Ottawa Scale, and the results were analyzed using Review Manager 5.4 software.

RESULTS

A total of 14 studies were included. Patients with OSF exhibited significantly higher levels of malondialdehyde (serum: SMD: 7.65, 95% confidence interval [CI]: 5.14-10.17, P < .00001, saliva: SMD: 3.07, 95% CI: 0.6-5.54, P < .00001) and 8-hydroxy-deoxyguanosine (saliva: SMD: 4.84, 95% CI: 3.49-6.18, P < .00001) than healthy controls. Levels of vitamin C (serum: SMD: -3.54, 95% CI: -4.10 to -2.99, P < .00001, saliva: SMD: -1.10, 95% CI: -1.39 to -0.80, P < .00001), vitamin E (saliva: SMD: -1.78, 95% CI: -2.1 to -1.45, P < .00001), and superoxide dismutase (serum: SMD: -9.77, 95% CI: -13.79 to -5.74, P < .00001) were significantly lower in patients with OSF than in healthy controls.

CONCLUSIONS

The results showed increased levels of OS markers and decreased levels of antioxidant markers in patients with OSF, providing valuable indicators that may aid in clinical diagnosis and management.

Unveiling Lipid Metabolic Shifts in Different Stages of Oral Submucous Fibrosis: A New Horizon in Predicting Malignant Transformation

Background

Oral Submucous Fibrosis (OSMF) is a chronic, progressive condition linked to areca nut consumption, with a high potential for malignant transformation into oral squamous cell carcinoma (OSCC). Changes in lipid metabolism have been implicated in cancer biology, yet the relationship between lipid profiles and OSMF progression remains underexplored. This study investigates the alterations in serum lipid parameters across different clinical stages of OSMF and their association with malignant transformation.

Materials and methods

A cross-sectional study was conducted over 69 OSMF patients, divided into five groups (Stage 1 to 3 and Stage 4a, 4b) based on clinical staging. Serum lipid profiles, including total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), and triglycerides (TG), were analyzed. Statistical analysis was performed using ANOVA and Tukey's post hoc test.

Results

Lipid levels (TC, HDL, LDL, VLDL, TG) showed a significant decline from Stage 1 to Stage 4a (p-0.00), followed by a sharp increase in Stage 4b (p-0.00), coinciding with malignant transformation. Particularly, HDL, VLDL, and TG were significantly elevated in Stage 4b compared to earlier stages.

Conclusion

Alterations in lipid metabolism (hypolipidemia) were observed from Stage 1 to 4a, with a marked shift (hyperlipidemia) during malignant transformation (Stage 4b). Increased levels of HDL, VLDL, and TG in advanced OSMF stages suggest their potential as predictive biomarkers for malignancy. Further research is required to elucidate the mechanisms linking lipid metabolism with OSMF progression and malignancy, paving the way for targeted therapeutic strategies.

Novel role of CD34+ stromal cells/telocytes in oral submucous fibrosis development and its malignant transformation

BACKGROUND

Telocytes are interstitial cells widely distributed in the extracellular matrix of numerous tissues distinguished by their long, thin, and moniliform projections. Telocytes have a role in the stimulation of angiogenesis and contribute to the development and progression of fibrosis.

AIM

The current study aimed to assess and compare the telocyte distribution in normal mucosa, oral submucous fibrosis (OSF), and OSCC associated with OSF (OSCCOSF).

MATERIALS AND METHODS

Formalin-fixed and paraffin-embedded tissue blocks of 30 OSF cases, 15 OSCCOSF cases, and 15 normal oral mucosae were obtained. Immunohistochemical staining was done with antibodies to CD34 to assess the vasculature and telocytes. The mean vascular density (MVD) and mean telocyte density were compared between the groups using the Kruskal-Walli test.

RESULTS

A statistically significant high MVD (3.4 ± 1.22) and mean telocyte density (3.8 ± 1.35) was observed in OSCCOSF cases while it was lowest in advanced OSF cases. MVD was higher in early OSF cases than in normal mucosa.

CONCLUSION

This study showed a decrease in CD34-positive telocytes in OSF, indicating that telocyte loss promotes the development of fibrosis.Increased angiogenesis coexisted with an increase in telocytes in OSCCOSF.

Comprehensive analysis of clinicopathological characteristics in oral squamous cell carcinoma arising from oral submucous fibrosis: a retrospective study

BACKGROUND

Oral squamous cell carcinoma arising from oral submucous fibrosis is recognized as a clinicopathologically distinct disease. This study aims to summarize and compare the population and clinicopathologic characteristics of OSCC-OSF with other OSCC in Hunan Province, China. The objective is to formulate treatment strategies more in line with regional characteristics.

METHODS

A retrospective review of OSCC cases recruited from the Second Xiangya Hospital from 2010 to 2020 was conducted. A total of 1,413 OSCC patients were selected, including 481 patients with OSCC-OSF and 932 were other OSCC. Population characteristics, risk factors and clinicopathological manifestations were explored in OSCC-OSF and other OSCC, as well as thinprep cytologic test and DNA quantification.

RESULTS

We found that OSCC-OSF patients were younger than those with other OSCC. Both types of disease were predominantly observed in males compared to females. Tumor biopsy analysis indicated that tumor cells within OSCC-OSF patients were more likely to be well differentiated and showed a higher frequency of lymph node metastases. Clinicopathological factors, such as the chewing betel nuts habit and smoking, were more prevalent in OSCC-OSF patients in contrast to other OSCC. DNA quantification revealed that the number of DNA aneuploid cells was higher in OSCC-OSF compared to other OSCCs.

CONCLUSION

In this study, OSCC-OSF is considered a clinicopathologically distinct disease. Compared with other OSCC, OSCC-OSF patients have a higher incidence of nodal metastases, an early clinical TNM stage, and a lower three-year survival rate. Therefore, early diagnosis and treatment are crucial to improving the prognosis of OSCC-OSF.

Expression profile of diagnostic genes in oral submucous fibrosis

Oral Submucous Fibrosis (OSMF) is a chronic precancerous disorder of the oral mucosa caused by chewing of areca nut and its other variants. Chewing of areca nuts leads to dysregulated expression of specific genes, leading to various premalignant or malignant disorders. This study aimed to determine the differential expression of the diagnostic genes (MYH6, TNNT3, MYL1, and TPM2) in healthy controls and OSMF patients using saliva and tissue samples, determining the histopathological grade of the clinical samples. A total of 20 patients were included in the study and were divided into two groups: Group I consisted of 10 healthy patients (control group) and Group II consisted of 10 OSMF patients. Unstimulated whole saliva samples were collected from both groups, and the tissue samples were divided into two parts: one for RT-qPCR analysis and the other for histopathological assay. The expression profile of genes concerning OSMF saliva and tissue samples was significantly upregulated compared to the healthy control, and all the clinical samples of the study were categorized into histopathological grade 1. The findings of this study concluded that these genes can be referred to as diagnostic genes for OSMF in early and very early clinical samples, and saliva can be used as a promising diagnostic tool for early OSMF studies.

Malignant transformation in oral submucous fibrosis: Tertiary level evidence: An umbrella review

OBJECTIVES

An umbrella review is a systematic review of systematic reviews, which provides a tertiary level of evidence. This umbrella review of systematic reviews and meta-analysis (SR-MA) aimed to determine the proportion of oral cancer (OC) development in oral submucous fibrosis (OSF) patients.

MATERIALS AND METHODS

We searched electronic databases including PubMed, Scopus, Web of Science, Cochrane and grey literature. Two reviewers independently screened abstracts and assessed for eligible papers. The methodological quality of SR-MA was evaluated using AMSTAR2, and we also checked the quality of evidence of the included papers.

RESULTS

Out of 454 papers identified in the primary search, 105 underwent eligibility screening. Inclusion criteria were met by four SR-MA. OC ratios ranged between 4.2% and 6% for OSF. Substantial heterogeneity was observed for this outcome in all four MA (I2 = 71.31% to 86.37%). None of the SRs assessed the quality of evidence, and half of them were judged to be of critically low methodological quality.

CONCLUSION

There is lack of quality of evidences and critically low methodological quality among SRs and MA leading to substantial heterogeneity. However, due to potentially malignant nature, OSF patients should be monitored carefully for early detection of OC.

Curcumin relieves arecoline-induced oral submucous fibrosis via inhibiting the LTBP2/NF-κB axis

BACKGROUND

Submucosal fibrosis (OSF) of the oral cavity is a chronic scarring disease. Arecoline (Are) is the driving factor for the occurrence and deterioration of OSF. Curcumin plays a vital anti-inflammatory role in Are-induced OSF development. However, its potential pharmacological mechanism needs to be elucidated.

METHODS

The relative molecular level was measured via qRT-PCR or Western blot. MTT assay, transwell assay and flow cytometry detected cell proliferation, migration, and apoptosis. The correlation between hypoxia-inducible factor-1α (HIF-1α) and LTBP2 promoter was confirmed through dual-luciferase reporter assay. ELISA was performed to detect inflammatory cytokines levels.

RESULTS

Curcumin alleviated Are-induced oral mucosal fibroblast cells fibrosis by reducing oral mucosa fibroblasts viability, promoting cell apoptosis, suppressing cell migration, and down-regulating the levels of fibrosis markers and inflammatory factors. Curcumin relieved Are-induced OSF via inhibiting HIF-1α. Mechanically, HIF-1α bound to the promoter of LTBP2 to transcriptionally activated LTBP2. LTBP2 knockdown relieved Are-induced OSF, and curcumin down-regulated LTBP2 via inhibiting HIF-1α to relieve Are-induced OSF. Moreover, curcumin decreased NF-κB signal associated proteins via inhibiting LTBP2 to relieve Are-induced OSF.

CONCLUSION

Curcumin reduced the transcription level of LTBP2 by inhibiting HIF-1α, thereby inactivating NF-κB pathway to alleviate Are-induced OSF.

Evaluation of stromal myofibroblasts in oral submucous fibrosis and its malignant transformation: An immunohistochemical study

BACKGROUND

Oral submucous fibrosis (OSF) is a precancerous lesion, with oral squamous cell carcinoma (OSCC) being the most prevalent malignancy affecting the oral mucosa. The malignant transformation of OSF into OSCC is estimated to occur in 7-13% of cases. Myofibroblasts (MFs) play pivotal roles in both physiological and pathological processes, such as wound healing and tumorigenesis, respectively. This study aimed to explore the involvement of MFs in the progression of OSF and its malignant transformation.

MATERIALS AND METHODS

In total, 94 formalin-fixed paraffin-embedded tissue blocks were collected, including normal oral mucosa (NOM; n = 10), early-moderate OSF (EMOSF; n = 29), advanced OSF (AOSF; n = 29), paracancerous OSF (POSF; n = 21), and OSCC (n = 5) samples. Alpha-smooth muscle actin was used for the immunohistochemical identification of MFs.

RESULTS

NOM exhibited infrequent expression of MFs. A higher staining index of MFs was found in AOSF, followed by EMOSF and NOM. Additionally, a significant increase in the staining index of MFs was found from EMOSF to POSF and OSCC. The staining index of MFs in NOM, EMOSF, AOSF, POSF, and OSCC was 0.14 ± 0.2, 1.69 ± 1.4, 2.47 ± 1.2, 3.57 ± 2.6, and 8.86 ± 1.4, respectively. All results were statistically significant (P < 0.05).

CONCLUSIONS

The expression of MFs exhibited a gradual increase as the disease progressed from mild to malignant transformation, indicating the contributory role of MFs in the fibrogenesis and potential tumorigenesis associated with OSF.

Plant leads for mitigation of oral submucous fibrosis: Current scenario and future prospect

The aim of this review is to enumerate medicinal plants and their bioactive compounds that may become potential leads in the mitigation of oral submucous fibrosis (OSMF) in the forthcoming future. It is focused on pathophysiology, risk factors, current treatment regimen, potential plant leads, and future therapies for OSMF. Data were extracted from a vast literature survey by using SciFinder, Web of Science, Google Scholar, and PubMed search engines with relevant keywords. Upon literature survey, we found that the phytochemical 'arecoline' present in the areca nut is the main causative agent of OSMF condition. Currently, OSMF is treated by immunomodulatory and anti-inflammatory agents such as corticosteroids, enzymes (hyaluronidase, chymotrypsin, and collagenase), anti-inflammatory mediators (isoxsuprine and pentoxifylline), dietary supplements (vitamins, antioxidants, and micronutrients), and anti-fibrotic cytokines like interferon-gamma that provides short-term symptomatic relief to OSMF patients. However, some plant leads have been proven effective in alleviating symptoms and mitigating OSMF, which ultimately improves the quality of OSMF patients' life. We concluded that plant drugs like lycopene, curcumin, Aloe vera, colchicine, and Glycyrrhiza glabra are effective against OSMF in various in vitro and/or clinical studies and are being used by modern and traditional practitioners.

Enhanced ZEB 1 stromal expression is a marker for epithelial mesenchymal transition in oral submucous fibrosis

Introduction

Oral submucous fibrosis is a progressive oral mucosal condition that is characterized by inflammation and persistent fibrosis. Epithelial Mesenchymal Transition is a crucial molecular event that contributes to tumor progression and fibrosis, with ZEB 1 and its effect on E-cadherin expression being key molecules in the process. Thera are no tissue level studies of these molecules in oral submucous fibrosis.

Objective

To evaluate the immunohistochemical expression of epithelial mesenchymal transition markers E-cadherin and ZEB1 in oral submucous fibrosis.

Methodology

A total of 30 cases of Oral submucous fibrosis (15 Early OSMF and 15 Advanced OSMF) classified based on the histopathological features were included in the study. Immunohistochemistry was done using two markers i.e. E-cadherin and ZEB1. The difference in the expression of E-Cadherin and ZEB1 among histo-pathological grades of OSMF was done by Mann-Whitney U test.

Results

A slight reduction in the E-cadherin expression was noted in Oral submucous fibrosis but marked enhanced expression of ZEB1 was seen in the connective tissue of OSMF.

Conclusion

An increase in intensity and percentage of positivity of ZEB 1 expression in connective tissue was observed in advanced cases as compared to early OSMF. This can be attributed to role of ZEB1 in mediating EMT via transdifferentiation of fibroblast into myofibroblast and thus predispose to fibrosis in OSMF.

Oral Submucous Fibrosis: A Review of the Current Concepts in Management

Oral submucous fibrosis (OSMF) is a precancerous disorder of the submucosa that causes inflammation and progressive fibrosis, leading to pronounced stiffness and trismus. Chewing betel nuts is a significant risk factor for OSMF in India. Arecoline from betel nuts and copper, which causes fibroblast dysfunction and the development of fibrotic bands, are the main components of betel quid. OSMF is distinguished by fibrosis in the submucosal region, which affects the majority of the oral cavity and results in advanced lockjaw due to rigidity in the lips, pharynx, cheeks, and upper third of the oesophageal canal, which progresses to dysphagia. The prevalence of OSMF is rising, particularly among younger generations, as more commercially available areca nut products like gutka (chewing tobacco) and others are being introduced. The severity of OSMF develops as the practice continues and is permanent. It also persists even after chewing has been stopped. The hallmark of oral submucous fibrosis (OSF) is abnormal collagen deposition. It is a precancerous condition and progresses to malignant tumours. Symptoms include ulcers, xerostomia, submucous fibrosis, burning sensation, and a reduction in mouth opening. Each of these drastically reduces the patient's quality of life. In the past, many treatment modalities have been tried but none of them has resulted in a cure for the disease. The primary focus of the treatment is to reduce the signs and symptoms so that the patient can have a better quality of life. Along with principles, conservative, medical, and surgical management issues have also been covered.

A Novel Herbal Paste Formulation of Turmeric, Tulsi, and Honey for the Treatment of Oral Submucous Fibrosis

Background and objectives Oral submucous fibrosis (OSMF) is a condition that affects the oral cavity and is characterized by the development of fibrous bands in the submucosal layers, leading to progressive difficulty in mouth opening and other symptoms. Inflammation and advancing fibrosis of the submucosal tissues are the hallmarks of this chronic, disabling illness of the oral cavity. The disorder is well known for having a propensity for cancer and is particularly linked to the habit of chewing tobacco and areca nuts. The study mentioned aims to compare the effectiveness of a novel herbal paste formulation containing turmeric, tulsi (holy basil), and honey in managing OSMF. The use of herbal remedies is common in traditional medicine, and turmeric and tulsi are known for their potential anti-inflammatory and antioxidant properties. Honey, too, is believed to have some therapeutic benefits. Methodology A study was conducted at MNR Dental College and Hospital, Sangareddy, Telangana, India, in the Department of Oral Medicine and Radiology (OMR) on 80 oral submucous fibrosis patients to evaluate the efficacy of a novel herbal paste formulation of turmeric, tulsi, and honey, comprising 77 males and three females. Patients were given a novel herbal paste formulation consisting of 10 g of turmeric powder and 10 g of tulsi powder, mixed in 10 ml of honey, to study subjects, and a placebo consisting of anti-oxidants was administered to control subjects for three months. The subjective and objective symptoms were recorded and statistically analyzed. Results The majority of the subjects were in the age group of 18-22 years, with an average age of 28.09+/-8.38 years with the most predominant habit of gutka chewing. A statistically significant change in the mouth opening, tongue protrusion, burning sensation, blanching of the mucous membrane, and reduction in palpable fibrous bands was found in the study subjects when compared to control subjects. Conclusion The present study evaluated the efficacy of a novel herbal paste formulation of turmeric, tulsi, and honey in the management of OSMF.

Comparison of triamcinolone with pentoxifylline and vitamin E efficacy in the treatment of stage 2 and 3 oral submucous fibrosis: A randomized clinical trial

Objective

The objective of this study was to assess the effectiveness of triamcinolone in combination with pentoxifylline and vitamin E in the treatment of patients with level two and three oral submucous fibrosis.

Methods

The study aimed to compare the efficacy of corticosteroid injections (triamcinolone) versus pentoxifylline and vitamin E in the therapy of patients with stage two and three oral submucous fibrosis. A total of 42 participants with indications and features of oral submucous fibrosis were enrolled between January 2020 and September 2021. The patients' age and mouth opening were evaluated, and descriptive statistics and paired t-test were used for analytical investigation.

Results

The study showed a statistically significant improvement in both treatment groups (p = 0.001) concerning pre- and post-treatment deviations. However, when comparing the standard differences in treatment outcomes between the two study groups, only mouth opening exhibited a statistically significant difference (p = 0.001).

Conclusions

The findings indicate that a treatment regimen combining pentoxifylline and triamcinolone can significantly alleviate oral submucous fibrosis symptoms, including mouth opening, pain, and flaring agitation, thereby enhancing the affected individual's quality of life.

Comparison of Immunohistochemical Markers in Oral Submucous Fibrosis and Oral Submucous Fibrosis Transformed to Oral Squamous Cell Carcinoma-A Systematic Review and Meta-Analysis

The objective of the study was to compare the expression of immunohistochemical (IHC) markers of oral submucous fibrosis (OSMF) (non-transformed group) to those of oral squamous cell carcinoma (OSCC) transformed from OSMF (transformed group). The search for comparative cross-sectional studies was carried out in PubMed and Scopus abiding to the PICO criteria, where expression of IHC markers in OSMF were compared with that of OSCC transformed from OSMF. The cellular distribution, number of positive cases, staining intensity, and mean immunoreactive score (IRS) of each IHC marker were evaluated in both groups. A total of 14 studies were included in the systematic review, in which immunoexpression of 15 epithelial and 4 connective tissue biomarkers were evaluated. Expression of β1-integrin, OCT-3, CD1a, CD207, survivin, Dickkopf-1, COX-2, hTERT, CTGF, MDM2, Ki-67, and α-SMA were increased during transformation of OSMF to OSCC. Conversely, expression of PTEN and lysyl oxidase decreased during transformation of OSMF to OSCC. Expression of a group of epithelial markers, such as COX2, hTERT, CTGF, survivin, MDM2, and p53, was 38 times lower in the non-transformed group cases compared to transformed group cases (95% CI: 58% to 10%; p = 0.01; and I² = 90%). Meta-analysis of all markers involved in cell metabolism/apoptosis, which included β1-integrin along with the above markers also suggested 42 times lower expression in the non-transformed group as compared to the transformed group (95% CI: 58% to 10%; p = 0.01; and I² = 90%). Sub-group analyses on cytoplasmic and nuclear epithelial markers were inconclusive. Meta-analysis of connective tissue markers was also inconclusive. No publication bias was found. Instead of delving into numerous markers without a strong basis for their use, it is advisable to further study the markers identified in this study to explore their clinical utility.

Clinicopathological Significance of Cancer Stem Cell Markers (OCT-3/4 and SOX-2) in Oral Submucous Fibrosis and Oral Squamous Cell Carcinoma

Oral submucous fibrosis (OSMF) is highly prevalent in South East Asia with higher rates of malignant transformation in Indian subcontinent. Numerous biomarkers are now being studied to predict disease prognosis and detect malignant alterations at an early stage. Patients with clinically and biopsy-proven oral submucous fibrosis and oral squamous cell carcinoma were included in the study as the experimental group, while patients without a tobacco or betel nut habit who had their third molars surgically removed were included as the healthy control group. For the immunohistochemistry (IHC) investigation, 5-μm slices from formalin-fixed, paraffin-embedded tissue blocks (FFPE) were obtained. Fresh tissues (n = 45) from all three groups were collected and gene expression was studied using relative quantitation-based qPCR. The protein expression of octamer-binding transcription factor 3/4 (OCT 3/4) and sex-determining region Y-box 2 (SOX 2) was evaluated in the experimental group and compared with healthy controls. The IHC results showed a significant correlation with the expression of OCT 3/4 (p value = 0.000; χ2 = 20.244) and SOX 2 (p value = 0.006; χ2 = 10.101) among OSCC and OSMF patients in comparison to healthy controls. Both OCT 3/4 and SOX 2 showed overexpression of four-fold and three-fold in OSMF when compared to OSCC and healthy controls, respectively. This study shows the significant importance of cancer stem cell markers OCT 3/4 and SOX 2 to assess the disease prognosis in OSMF.

Implications of altered sirtuins in metabolic regulation and oral cancer

Sirtuins (SIRTs 1-7) are a group of histone deacetylase enzymes with a wide range of enzyme activities that target a range of cellular proteins in the nucleus, cytoplasm, and mitochondria for posttranslational modifications by acetylation (SIRT1, 2, 3, and 5) or ADP ribosylation (SIRT4, 6, and 7). A variety of cellular functions, including mitochondrial functions and functions in energy homeostasis, metabolism, cancer, longevity and ageing, are regulated by sirtuins. Compromised sirtuin functions and/or alterations in the expression levels of sirtuins may lead to several pathological conditions and contribute significantly to alterations in metabolic phenotypes as well as oral carcinogenesis. Here, we describe the basic characteristics of seven mammalian sirtuins. This review also emphasizes the key molecular mechanisms of sirtuins in metabolic regulation and discusses the possible relationships of sirtuins with oral cancers. This review will provide novel insight into new therapeutic approaches targeting sirtuins that may potentially lead to effective strategies for combating oral malignancies.

Is Epithelial-Mesenchymal Transition a New Roadway in the Pathogenesis of Oral Submucous Fibrosis: A Comprehensive Review

Epithelial-mesenchymal transition (EMT) collectively refers to a series of episodes that reshape polarized, intact epithelial cells into discrete motile cells that can conquer the extracellular matrix (ECM). It performs a pivotal role in embryonic development, wound healing, and tissue repair. Surprisingly, the exact mechanism can also lead to the onset of malignancy and organ fibrosis contributing to scar formation and loss of function. transforming growth factor signaling, WNT signaling, Notch signaling, Hedgehog signaling, and receptor tyrosine kinase signaling, as well as non-transcriptional changes in response to extracellular cues, such as growth factors and cytokines, hypoxia, and contact with the surrounding ECM, are responsible for the initiation of EMT.

Although the pathogenesis of oral submucous fibrosis (OSMF) is multifactorial, compelling evidence suggests that it results from collagen deregulation. EMT is one of the spotlight events in the pathogenesis of OSMF, with myofibroblasts and keratinocytes being the victim cells. EMT is an essential step in both physiological and pathological events. The importance of EMT in the malignant development of OSMF and the inflammatory reaction preceding fibrosis implies a new upcoming area of research.

This review aims to focus on the EMT events that function as a double-edged sword between wound healing and fibrosis and further discuss the mechanisms along with the molecular pathways that direct changes in gene expression essential for the same in the oral cavity. As OSMF involves a risk of malignant transformation, understanding the cellular and molecular events will open more avenues for therapeutic breakthroughs targeting EMT.

Overexpression of DEC1 in the epithelium of OSF promotes mesenchymal transition via activating FAK/Akt signal axis

BACKGROUND

Previous studies on oral submucous fibrosis (OSF) mostly focused on the activation of fibroblasts and collagen metabolism, while little involved in the epithelium. As we have reported the role of differentiated embryo chondrocyte expressed gene 1 (DEC1) in oral cancer and other precancerous lesions, this research aimed to explore its role in the OSF epithelium.

METHODS

Expression of DEC1 and other proteins were investigated in tissue array constructed with 33 OSF and 14 normal oral mucosa (NOM) tissues. Human oral keratinocytes treated with arecoline and/or hypoxia were used to simulate OSF epithelium and detected for morphological and protein alterations. Inhibition of DEC1 was used to explore its mediating role. Finally, animal models of OSF constructed by locally arecoline injecting in buccal mucosa were used to verify our findings.

RESULTS

DEC1 overexpression could be detected in the epithelium of OSF compared with that in NOM followed by phosphorylated FAK and Akt, and DEC1 showed a significant positive correlation with them. Cytology experiment revealed that OSF-like treatment could upregulate DEC1 expression followed by phosphorylated FAK, Akt, but inhibit E-cadherin, while knockdown of DEC1 could suppress the effects. Additionally, OSF mice revealed higher expression of DEC1 in the epithelium of buccal mucosa, along with synchronized alterations of phosphorylated FAK and Akt.

CONCLUSION

In the epithelium of OSF, overexpression of DEC1 induced activation of FAK/Akt signal axis, caused mesenchymal transition in epithelial cells, and may promote malignant transformation of OSF. Targeting DEC1 in OSF could be promising a new target for the diagnosis and treatment of this process.

Update from the 5th Edition of the World Health Organization Classification of Head and Neck Tumors: Tumours of the Oral Cavity and Mobile Tongue

The fifth chapter of the upcoming fifth edition of the 2022 World Health Organization Classification of Tumours of the Head and Neck titled Tumours of the oral cavity and mobile tongue, has had some modifications from the 2017 fourth edition. A new section "Non-neoplastic Lesions", introduces two new entries: necrotizing sialometaplasia and melanoacanthoma. The combined Oral potentially malignant disorders and Oral epithelial dysplasia section in the 2015 WHO has now been separated and submucous fibrosis and HPV-associated dysplasia are also discussed in separate sections. Carcinoma cuniculatum and verrucous carcinoma are described in dedicated sections, reflecting that the oral cavity is the most common location in the head and neck for both these entities which have distinct clinical and histologic features from conventional squamous cell carcinoma. This review summarizes the changes in Chapter 5 with special reference to new additions, deletions, and sections that reflect current clinical, histological, and molecular advances.

Arecoline Enhances Phosphodiesterase 4A Activity to Promote Transforming Growth Factor-β-Induced Buccal Mucosal Fibroblast Activation via cAMP-Epac1 Signaling Pathway

Chewing areca nut (betel quid) is strongly associated with oral submucous fibrosis (OSF), a pre-cancerous lesion. Among the areca alkaloids, arecoline is the main agent responsible for fibroblast proliferation; however, the specific molecular mechanism of arecoline affecting the OSF remains unclear. The present study revealed that arecoline treatment significantly enhanced Transforming growth factor-β (TGF-β)-induced buccal mucosal fibroblast (BMF) activation and fibrotic changes. Arecoline interacts with phosphodiesterase 4A (PDE4A) to exert its effects through modulating PDE4A activity but not PDE4A expression. PDE4A silence reversed the effects of arecoline on TGF-β-induced BMFs activation and fibrotic changes. Moreover, the exchange protein directly activated by cAMP 1 (Epac1)-selective Cyclic adenosine 3′,5′-monophosphate (cAMP) analog (8-Me-cAMP) but not the protein kinase A (PKA)-selective cAMP analog (N6-cAMP) remarkably suppressed α-smooth muscle actin(α-SMA) and Collagen Type I Alpha 1 Chain (Col1A1) protein levels in response to TGF-β1 and arecoline co-treatment, indicating that cAMP-Epac1 but not cAMP-PKA signaling is involved in arecoline functions on TGF-β1-induced BMFs activation. In conclusion, arecoline promotes TGF-β1-induced BMFs activation through enhancing PDE4A activity and the cAMP-Epac1 signaling pathway during OSF. This novel mechanism might provide more powerful strategies for OSF treatment, requiring further in vivo and clinical investigation.

Understanding the molecular mechanism associated with reversal of oral submucous fibrosis targeting hydroxylysine aldehyde-derived collagen cross-links

Fibrosis is a pathological state characterized by excessive deposition of the extracellular matrix components leading to impaired tissue function in the affected organ. It results in scarring of the affected tissue akin to an over-healing wound as a consequence of chronic inflammation and repair in response to injury. Persistent trauma of susceptible oral mucosa due to habitual chewing of betel quid resulting in zealous healing of the mucosal tissue is one plausible explanation for the onset of oral submucous fibrosis (OSF). The irreversibility and resistance of collagen to degradation and its high potential to undergo malignant change are a major reason for morbidity in OSF. Hence, early diagnosis and timely treatment are crucial to prevent the progression of OSF to malignancy. This review focuses on the mechanistic insight into the role of collagen cross-links in advancing fibrosis and possible therapeutic targets that bring about a reversal of fibrosis. These options may be beneficial if attempted as a specific therapeutic modality in OSF as is in organ fibrosis. The upregulation of lysyl oxidase and lysyl hydroxylase has been shown to exhibit the higher levels of the hydroxylysine aldehyde-derived cross-links in fibrosis and tumor stroma promoting the tumor cell survival, resistance, and invasion. The in silico analysis highlights the potential drugs that may target the genes regulating collagen crosslinking.

Optical Microscopy and the Extracellular Matrix Structure: A Review

Biological tissues are not uniquely composed of cells. A substantial part of their volume is extracellular space, which is primarily filled by an intricate network of macromolecules constituting the extracellular matrix (ECM). The ECM serves as the scaffolding for tissues and organs throughout the body, playing an essential role in their structural and functional integrity. Understanding the intimate interaction between the cells and their structural microenvironment is central to our understanding of the factors driving the formation of normal versus remodelled tissue, including the processes involved in chronic fibrotic diseases. The visualization of the ECM is a key factor to track such changes successfully. This review is focused on presenting several optical imaging microscopy modalities used to characterize different ECM components. In this review, we describe and provide examples of applications of a vast gamut of microscopy techniques, such as widefield fluorescence, total internal reflection fluorescence, laser scanning confocal microscopy, multipoint/slit confocal microscopy, two-photon excited fluorescence (TPEF), second and third harmonic generation (SHG, THG), coherent anti-Stokes Raman scattering (CARS), fluorescence lifetime imaging microscopy (FLIM), structured illumination microscopy (SIM), stimulated emission depletion microscopy (STED), ground-state depletion microscopy (GSD), and photoactivated localization microscopy (PALM/fPALM), as well as their main advantages, limitations.

Oral submucous fibrosis presenting with histopathological lichenoid changes as predominant feature: Report of five cases and review of the literature

Oral submucous fibrosis (OSF) is a precancerous condition of the oral cavity associated with habitual chewing of quid, with a high incidence among populations of the Indian subcontinent and Southeast Asia. Clinically, its initial manifestation may mimic oral lichen planus or lichen sclerosus. If the habit is not halted, the mucosa gets leathery and thickened, and fibrous bands form causing significant morbidity. Microscopically, it is characterized by atrophic epithelium, loss of rete ridges, and hyalinization of lamina propria. Of note, these hallmark histopathological features may be overlooked in the unusual presence of lichenoid interface changes, which may lead to the wrong diagnosis. We present herein five cases in which the rare joint appearance of OSF and lichenoid reaction features posed a diagnostic challenge. Due to its progressive nature and malignant potential, the presence of oral lichenoid changes overlying submucous hyalinization, in the right clinical and demographic setting, should raise suspicion of OSF and prompt actions directed at quid-chewing discontinuation.

Curcumin relieves the arecoline-induced fibrosis of oral mucosal fibroblasts via inhibiting HIF-1α/TGF-β/CTGF signaling pathway: an in vitro study

Oral submacosal fibrosis (OSF) has been recognized as one of the oral potentially malignant disorders. Areca nut chewing is implicated in this pathological fibrosis. The current treatments for OSF have failed to achieve the desired curative effect. Here, we propose that curcumin has excellent therapeutic effect on OSF and explore its specific mechanism. Transwell assay was performed to detected cell migration. Flow cytometry was used to measured apoptosis. And MTT assay was performed to test cell viability. Gene and protein levels were detected by quantitative real-time polymerase chain reaction (qPCR) and western blotting. Our results displayed that curcumin treatment reduced fibrosis-related molecules (collagen type I alpha 1, collagen type III alpha 1, tissue inhibitor of metalloprotease 2) in arecoline-treated oral mucosal fibroblasts and elevated matrix metalloproteinase 2 expression. Additionally, curcumin could suppress cell proliferation and migration, and enhance the apoptosis of arecoline-treated normal oral mucosal fibroblasts. Most importantly, the hypoxia-inducible factor-1α (HIF-1α), transforming growth factor-β (TGF-β) and connective tissue growth factor (CTGF) expressions in arecoline-treated normal oral mucosal fibroblasts were reduced after exposure to curcumin, whereas the activation of HIF-1α/TGF-β/CTGF axis reversed curcumin's effect on improving fibrosis of arecoline-treated normal oral mucosal fibroblasts. Therefore, curcumin alleviated oral submucosal fibrosis via inhibiting HIF-1α/TGF-β/CTGF axis. In summary, curcumin effectively inhibited the migration and proliferation and promoted apoptosis in arecoline-induced normal oral mucosal fibroblasts by inactivating HIF-1α/TGF-β/CTGF pathway. And curcumin might be a potential therapeutic drug for OSF treatment.

Estimation of salivary matrix metalloproteinases- 12 (MMP- 12) levels among patients presenting with oral submucous fibrosis and oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma is a global threat and accounts for approximately 90% of malignant oral lesions. The emergence of oral carcinoma is linked to precancerous lesions, which act as precursors of the disease. Matrix metalloproteinases appear to play a significant role in the pathogenesis of both precancerous conditions and oral malignancies due to their participation in remodeling of the extracellular matrix.

METHODOLOGY

This is an analytical study conducted at Dow University of Health Sciences, Pakistan. Unstimulated saliva samples were collected from healthy, oral submucous fibrosis and oral squamous cell carcinoma patients. The level of MMP-12 was estimated using enzyme-linked immunosorbent assay. One-way Analysis of variance was run to determine if MMP-12 levels differ between the three groups, which was preceded by post hoc Tuckey test. MMP-12 cut off values were determined using Receiver operating characteristic curve.

RESULTS

A significant difference in salivary MMP-12 expression was observed in OSF and OSCC (p < 0.001). The expression of salivary MMP-12 was higher in OSF and OSCC patients as compared to the healthy group (p < 0.001). The mean MMP-12 expression in OSCC appeared higher than in OSF cases (p < 0.05). MMP-12 value of [Formula: see text] 4.05 ng/ml and [Formula: see text] 4.20 ng/ml is predictive of OSF and OSCC respectively, with 100% sensitivity and specificity (p < 0.001).

CONCLUSION

Increased expression of MMP-12 appears as the healthy patient advances to OSF and OSCC. The study results also demonstrate higher MMP-12 expression in OSCC patients as compared to OSF. Therefore, the estimation of salivary MMP-12 serves as a valuable non-invasive early diagnostic tool in diagnosing oral submucous fibrosis and oral squamous cell carcinoma.

Quality of Life in Oral Submucous Fibrosis- A Case Report with a Literature Review

Introduction:

Oral Submucous Fibrosis (OSMF) is a potentially malignant disorder commonly found in the Southeast Asian region, classically characterized through restricted mouth opening and burning sensation in the mouth on consuming spicy food. The etiopathogenesis and treatment aspects of OSMF have been extensively researched and reviewed. However, the effect of this condition on the Quality of Life (QoL) of patients has not gained much consideration. The aim of our case report is to highlight the importance of evaluating the QoL in an OSMF patient by using discipline-specific questionnaire and also to present to the readers a review of the recently published research articles on the application of QoL questionnaires in OSMF patients.

Results:

It was observed that most of the researchers used generic and discipline-specific questionnaire for evaluating the quality of life in OSMF patients.

Conclusion:

Evaluation of QoL is recommended during the treatment of OSMF patients. There is a need to develop and employ more of disease-specific QoL instruments for OSMF patients.

The Role of Increased Connective Tissue Growth Factor in the Pathogenesis of Oral Submucous Fibrosis and its Malignant Transformation-An Immunohistochemical Study

Connective tissue growth factor (CTGF), a matricellular protein of the CCN family of extracellular matrix-associated heparin-binding proteins, is highly expressed in various organ fibrosis and several malignant tumors. Although a few studies have been conducted using CTGF in oral submucous fibrosis (OSF) and oral squamous cell carcinoma, no study has demonstrated its relation with various stages of OSF and its malignant transformation. The present study investigated the possible role of CTGF in the pathogenesis of OSF and its malignant transformation by using immunohistochemistry. Ten formalin-fixed paraffin-embedded tissue blocks, each of Stage 1 OSF, Stage 2 OSF, Stage 3 OSF, Stage 4 OSF, well- differentiated squamous cell carcinoma (WDSCC) with OSF and WDSCC without OSF were stained for CTGF by immunohistochemistry. Ten cases of healthy buccal mucosa (NOM) were included as controls. The present study demonstrated a statistically significant expression of CTGF in the epithelium and connective tissue of OSF and WDSCC with and without OSF cases against its complete absence in NOM. We observed an upregulation of CTGF expression from NOM to various stages of OSF to WDSCC with or without OSF. A gradual upregulation of the CTGF expression in various stages of OSF to WDSCC (with and without OSF) against its complete absence in NOM suggests that CTGF plays an important role in the pathogenesis of OSF and its malignant transformation.

Signaling pathways promoting epithelial mesenchymal transition in oral submucous fibrosis and oral squamous cell carcinoma

Epithelial-mesenchymal transition (EMT) is a critical process that occurs during the embryonic development, wound healing, organ fibrosis and the onset of malignancy. Emerging evidence suggests that the EMT is involved in the invasion and metastasis of cancers. The inflammatory reaction antecedent to fibrosis in the onset of oral submucous fibrosis (OSF) and the role of EMT in its malignant transformation indicates a hitherto unexplored involvement of EMT. This review focuses on the role of EMT markers which are regulators of the EMT mediated complex network of molecular mechanisms involved in the pathogenesis of OSF and OSCC. Further the gene enrichment analysis and pathway analysis supports the association of the upregulated and downregulated genes in various EMT regulating pathways.

A systematic review on the mechanisms of malignant transformation of oral submucous fibrosis

Oral submucous fibrosis (OSMF), the most commonly encountered potentially premalignant oral epithelial lesion, is a chronic disorder associated with areca nut chewing. It has a relatively high potential for malignant transformation resulting into oral squamous cell carcinoma (OSCC), the most common oral malignancy with high mortality rate. Paymaster first described the malignant potential of OSMF in 1956, the rate of which had been estimated to be 7-13%. The pathogenesis of OSMF in itself is quite varied, and hence, its transformation to malignancy is also open to many varied mechanisms. The early diagnosis and sequentially, early treatment of OSMF is desirable so that the progression towards malignancy can be controlled. There are various theories that have been put forward explaining the probable pathway of malignant transformation of OSMF such as hypoxia, areca nut as a carcinogen or epithelial-mesenchymal transitions. Many recent molecular advances have also highlighted few biomarkers and genes that play a pivotal role in transformation of OSMF to OSCC. The purpose of this systematic review is to discuss all the possible mechanisms of malignant transformation of OSMF. Further research is still needed to establish the exact mechanism responsible for transformation of OSMF to OSCC and to reduce the mortality by newer interventions.

Expression of Survivin in Oral Potentially Malignant Disorders: An Immunohistochemical Study

AIM

The aim of this study was to compare the immunohistochemical expression of survivin in oral potentially malignant disorders (OPMDs) and evaluate its prognostic significance among oral leukoplakia (OL), oral submucous fibrosis (OSMF), and oral lichen planus (OLP).

MATERIALS AND METHODS

The study material consisted of 60 formalin-fixed paraffin-embedded tissue samples: 15 cases each of OL, OSMF, OLP, and normal oral mucosal epithelium as control. Survivin expression was analyzed immunohistochemically, and data analysis was accomplished using Statistical Package for Social Sciences, version 22.0 (SPSS Inc., Chicago, IL). Fisher's chi-square test was opted to compare the study groups.

RESULTS

Survivin was expressed in all the OPMDs including OL, OSMF, and OLP, but was absent in normal oral tissue samples. Higher immunoreactivity and survivin staining was observed in OLP compared to OL and OSMF whereas OL showed a significant difference in the distribution of survivin immunoexpression against OLP. An increased nuclear expression of survivin along with distribution in the basal and parabasal layers was evident in all OPMDs.

CONCLUSION

Survivin was expressed more in OLP in comparison to OSMF and OLP, indicating unfavorable prognosis. OL showed increased expression in comparison to OSMF, showing unfavorable prognosis. On the basis of this study, it was concluded that survivin may be used as an important diagnostic and prognostic marker for OPMDs.

Ki67, CD105, and α-SMA Expression Supports Biological Distinctness of Oral Squamous Cell Carcinoma Arising in the Background of Oral Submucous Fibrosis

BACKGROUND

The clinicopathological distinctness of oral squamous cell carcinoma arising in the background of oral submucous fibrosis (OSCC-OSF) is well known; however, the molecular distinctness of this unique OSCC-OSF has not been investigated to date. With this in mind, we compared the expression of Ki67, CD105, and α-SMA between OSCC-OSF and oral squamous cell carcinoma (OSCC).

METHODS

Formalin-fixed paraffin-embedded tissues of 105 OSCC-OSF and 112 OSCC cases were subjected to immunohistochemistry for evaluation of Ki67, CD105, and α-SMA expression.

RESULTS

Ki67 (labeling index) LI, MVD and α-SMA expression were significantly higher in OSCC compared to OSCC-OSF. Ki67 LI and MVD was significantly higher in OSCC compared to OSCC-OSF in parameters such as well-differentiated, early TNM stage, non-metastatic, and more than 3-year survival. α-SMA expression was significantly higher in OSCC compared to OSCC-OSF in parameters such as moderate differentiation, metastatic lesions, and survival less than 3 years. Ki67 LI, MVD and α-SMA showed significant positive correlation with each other in OSCC and OSCC-OSF.

CONCLUSION

Proliferation, neoangiogenesis and myofibroblast differentiation were significantly higher in the OSCC group compared to the OSCC-OSF group. This suggests the biological distinctness of OSCC-OSF, which could help the future development of targeted therapies.

Qualitative expression of hypoxia-inducible factor-1α in malignant transformation of oral submucous fibrosis: An immunohistochemical study

Background

Oral submucous fibrosis (OSF) is a precancerous condition predominantly seen in people of Asian descent. About 7%-12% of OSF patients develop oral squamous cell carcinoma. Morphological features of OSF, especially fibrosis, suggest a possibility of hypoxic environment in diseased tissues. Neovascularization and increased glycolysis, represent adaptations to a hypoxic microenvironment that are correlated with tumor invasion and metastasis. The adaptation of cells to hypoxia appears to be mediated through hypoxia-inducible factor-1α (HIF-1α). HIF-1α is said to be associated with malignant transformation of epithelium in other sites.

Aim

The aim of this study was to investigate the relationship between the expression of HIF-1α in OSMF and its role in malignant transformation.

Materials and Methods

A retrospective study which included 20 histopathologically diagnosed cases of OSF was conducted. A qualitative evaluation of HIF-1α was performed. Statistical analysis was carried out using the IBM Statistical Package for Social Sciences 20.0 version (IBM Corporation, Armonk, NY, USA).

Results

Results showed an increased expression of HIF-1α in OSF.

Conclusion

HIF-1α appears to play a role in malignant transformation of OSF.

In vitro Quantification of Collagen and Snail1 Gene Expression in Experimentally Induced Fibrosis by Arecoline and Commercial Smokeless Tobacco Products

INTRODUCTION

Extracellular matrix component derangement is the major event in pathogenesis of Oral submucous fibrosis. Many studies have elaborated the alteration of the matrix components at a cellular and genetic level. However elaborate quantification of the components with varying concentrations of Areca nut extract  and commercial tobacco products have not been done so far.

MATERIALS AND METHODS

Primary culture of tissues sourced during crown lengthening procedures were used for establishment of fibroblast monoculture and fibroblast / keratinocyte co-culture. Extracts of areca nut, commercial smokeless tobacco products (gutkha and haans) and control CCl4 were tested at concentrations  ranging from 20 μL, 40 μL, 80 μL, 160 μL, 320 μL and time intervals of 12, 24, 48, 72 hours. Collagen quantification by spectrophotometry and SNAI1 gene expression study were done.

RESULTS

Extract of areca nut was found to show increased collagen production than commercial tobacco products and closely similar values to CCL4. Kruskal Wallis test was used to analyse the difference in collagen obtained. The mean values of collagen obtained in co-culture were lesser than those obtained in the fibroblast monoculture. SNAI1 gene expression was negative in both the culture experiments.

CONCLUSION

Areca nut extract was found to be more potent as an individual agent. Commercial smokeless tobacco products Gutka and Hans exhibited increased collagen production at higher concentration. These findings further steps up the persuasive ill effects of  tobacco products. Negative SNAI1 gene expression was corroborated to  lack of extracellular environment in the co coculture experiment.

Comparative Evaluation of SMAD-2 Expression in Oral Submucous Fibrosis and Reactive Oral Lesions

BACKGROUND

The event of fibrosis encompasses involvement of definite immunological and molecular mechanisms. As quite a lot of pro-fibrotic pathways are concerned, a multipronged approach is obligatory to cognize the fibrotic events. SMAD signaling pathway hasn't been studied oral fibrotic events.In the progression of cramming the SMAD signaling pathway in OSMF, the first initiator protein of the pathway was considered for evaluation in the present study.

MATERIALS AND METHODS

A total of 100 subjects consisting of 20 controls, 40 patients with reactive lesions such as Traumatic Fibroma, Epulis Fissuratum and Gingival Hyperplasia and 40 patients with Oral Submucous Fibrosis were recruited for the study. Tissue homogenates were assayed by quantitative sandwich enzyme immunoassay technique using Human Mothers Against Decapentaplegic Homolog 2 (Smad2).

RESULTS

SMAD 2 expression values showed significant difference between control and OSMF group. However, the difference between reactive lesions with control and OSMF were not statistically significant.

CONCLUSION

Graded increase of SMAD 2 expression from control,reactive lesions and OSMF were observed accentuating the role of SMAD signalling pathway in fibro genesis. Further this can be validated to generate effective antifibrotic targets.

Evaluation of Ki-67 Expression in Oral Submucous Fibrosis and Its Correlation with Clinical and Histopathological Features

Objectives:

Oral submucous fibrosis (OSMF) is a potentially malignant disorder. Although it shows atrophic epithelium, it has a high proliferative capacity. Therefore, this study correlates the Ki-67. (The name “ki” is derived from the city of origin [Kiel, Germany] expression with functional grading and epithelial thickness in OSMF).

Methods:

The study group comprised of thirty patients of OSMF, divided randomly into Group A, Group B, Group C, and Group D as per mouth opening (functional staging). Five participants without OSMF formed the negative control group. The positive control group comprised of five patients of diagnosed cases of squamous cell carcinoma. All the sections of biopsy were subjected for hematoxylin and eosin and immunohistochemistry staining and observed for expression of Ki-67. Epithelial thickness was evaluated using image analysis software of Leica research microscope. Images were analyzed by three independent observers who were blindfolded. All the findings were tabulated and statistically analyzed.

Results:

In the present study, as the functional staging increased, the Ki-67 expression also increased. Ki-67 expression was highest in severe functional staging/severely decreased mouth opening (100.78) and is least in mild functional staging/mild decreased mouth opening (10.39). However, there was no significant correlation between epithelial thickness and functional staging/mouth opening (P > 0.05).

Conclusion:

A decrease in functional staging (mouth opening) showed a greater expression of Ki-67, and there was no significant correlation between functional staging and epithelial thickness.

Elucidation of Differential Nano-Textural Attributes for Normal Oral Mucosa and Pre-Cancer

Computational analysis on altered micro-nano-textural attributes of the oral mucosa may provide precise diagnostic information about oral potentially malignant disorders (OPMDs) instead of an existing handful of qualitative reports. This study evaluated micro-nano-textural features of oral epithelium from scanning electron microscopic (SEM) images and the sub-epithelial connective tissue from light microscopic (LM) and atomic force microscopic (AFM) images for normal and OPMD (namely oral sub-mucous fibrosis, i.e., OSF). Objective textural descriptors, namely discrete wavelet transform, gray-level co-occurrence matrix (GLCM), and local binary pattern (LBP), were extracted and fed to standard classifiers. Best classification accuracy of 87.28 and 93.21%; sensitivity of 93 and 96%; specificity of 80 and 91% were achieved, respectively, for SEM and AFM. In the study groups, SEM analysis showed a significant (p < 0.01) variation for all the considered textural descriptors, while for AFM, a remarkable alteration (p < 0.01) was only found in GLCM and LBP. Interestingly, sub-epithelial collagen nanoscale and microscale textural information from AFM and LM images, respectively, were complementary, namely microlevel contrast was more in normal (0.251) than OSF (0.193), while nanolevel contrast was more in OSF (0.283) than normal (0.204). This work, thus, illustrated differential micro-nano-textural attributes for oral epithelium and sub-epithelium to distinguish OPMD precisely and may be contributory in early cancer diagnostics.

Multifaceted Mechanisms of Areca Nuts in Oral Carcinogenesis: the Molecular Pathology from Precancerous Condition to Malignant Transformation

Oral cancer is one of the most frequent malignant diseases worldwide, and areca nut is a primary carcinogen causing this cancer in Southeast Asia. It has been widely reported that areca nut induced several cytotoxic effects in oral cells, including ROS generation, inflammation, tissue hypoxia, DNA damage, and cell invasion. Recently, through chronic exposure model, more extensive pathological effects due to areca nut have been found. These include the induction of autophagy, promotion of epithelial- mesenchymal transition, and facilitation of cancer stemness conversion. Clinical findings support these adverse effects. Oral submucosal fibrosis, a premalignant condition, is prevalent in the area with habitual chewing of areca nuts. Consistently, oral cancer patients with habitual chewing areca nut exhibit more aggressive phenotypes, including resistance to chemo-radiotherapy. In this review, we comprehensively discuss and concisely summarize the up-to-date molecular and cellular mechanisms by which areca nuts contribute to malignant transformation. This review may provide critical information regarding clinical applications in risk assessment, disease prevention, diagnosis, and personalized therapeutics for areca nut-induced oral malignancy.

Oral Submucous Fibrosis: A Review on Etiopathogenesis, Diagnosis, and Therapy

Oral submucous fibrosis (OSF) is characterized by abnormal collagen deposition. It is a precancerous disorder and transforms into a malignant tumor in 1.5–15% of all cases. Symptoms include submucous fibrosis, ulceration, xerostomia, a burning sensation, and restricted mouth opening. All of these greatly interfere with patient quality of life. The present review introduces OSF from a molecular perspective and summarizes what is known about its underlying mechanisms, diagnostic biomarkers, and therapeutic interventions. In addition to the aggressive treatment of OSF, its prevention is also important. Future research should, therefore, focus on improving the oral health literacy of the patients susceptible to OSF.

Assessment of epithelial-mesenchymal transition signatures in oral submucous fibrosis

Background:

Recently, the concept of field cancerization has questioned the accuracy of biopsy site selection clinically. Oral submucous fibrosis (OSMF) has a global malignant transformation rate of 7.6% despite having less dysplastic changes clinically or histologically. Hence, this study was undertaken to evaluate the expression of vimentin, epithelial-cadherin (E-Cad) and collagen IV in OSMF, using immunohistochemistry and polymerase chain reaction (PCR).

Materials and Methods:

One hundred and eighty- five patients with OSMF (61), with habits and no OSMF (61) and patients without habit and OSMF (63) were subjected to biopsy for sample collection. The samples were analyzed immunohistochemically for vimentin, E-Cad and collagen IV. The PCR values for vimentin and E-Cad were also done.

Results:

Vimentin expression was increased in OSMF patients, whereas E-Cad expression was decreased in OSMF patients.

Conclusion:

Epithelial–mesenchymal transition signatures are definitely positive in OSMF cases.

Sirtuin 1 and oral cancer

The sirtuins (SIRTs) are a family of highly conserved histone deacetylases (HDACs) consisting of seven members (SIRT1-SIRT7). Over the past few decades, SIRT1 has been the most extensively studied and garnered tremendous attention in the scientific community due to its emerging role in cancer biology. However, its biological role in the regulation of oral cancer is not yet fully understood. Owing to contradictory findings regarding the role of SIRT1 in oral cancer, debate about it continues. The present study discusses the biological roles and potential therapeutic implications of SIRT1 in precancerous oral lesions and oral cancer.

An Evaluation of Clinical and Histopathological Aspects of Patients with Oral Submucous Fibrosis in the Background of Oral Squamous Cell Carcinoma

Background

The behavior and prognosis of oral squamous cell carcinoma (OSCC) is presumably different in patients with oral submucous fibrosis (OSF). The objective of this study was to assess the effects of demographic features, habits, and histopathological features in the transformation of OSF to OSCC.

Methods

Data were extracted from the archives and histopathological evaluation and presence of nodal metastasis were recorded.

Results

OSF was detected in 130 (48%) out of 273 OSCC patients. The mean age of presentation among OSF-positive patients was 57.7 years, while patients diagnosed only with OSCC had a comparatively higher age, 59.5 years. In the below 50 years of age group, presence of OSF with OSCC was less (40%). In the OSF-positive group, male to female ratio was 3.2:1. The common primary sites were buccal mucosa and tongue in both groups. Betel quid chewing was present in more than 95% of the sample. Betel chewing, smoking, and alcohol consumption were present in 26.15% of OSF-positive patients. Degree of fibrosis was neither associated with the level of histological differentiation of the tumor (p= 0.195) nor associated with the malignant transformation (p =0.373). Lymph node metastasis was not seen in 76.63% and 68.54% of the patients with and without OSF, respectively.

Conclusions

High degree of prevalence of OSF was observed among the OSCC patients. There were also a male predilection and younger age at presentation in these patients. However, a significant association was not observed in the degree of fibrosis with malignant transformation or the level of histopathological differentiation of the tumor. Lymph node metastasis also failed to express a significant relationship with the presence of OSF.

Ki67, CD105, and α-SMA expression supports the transformation relevant dysplastic features in the atrophic epithelium of oral submucous fibrosis

Background

The grading of oral epithelial dysplasia is not possible in the atrophic epithelium of oral submucous fibrosis (OSMF). Recently, we found that features such as increased basal cell layer hyperplasia, abnormal superficial mitosis, increased nuclear-cytoplasmic ratio, increased nuclear size, and hyperchromasia represent transformation-relevant dysplastic features in the atrophic epithelium of OSMF. The presence of these features can be considered a high-risk feature for patients. However, these findings have not been tested and authenticated using markers relevant to oral carcinogenesis.

Method

Paraffin-embedded tissues from 30 normal oral mucosa (NOM) and 50 OSMF were retrieved from 2008 to 2016 and subjected to immunohistochemical expression using Ki67, CD105 and α-SMA antibodies.

Results

Ki67 LI showed significant increases from NOM (12.47±2.34) to LRED (23.47±3.75) to HRED (34.31±7.31) (<0.0001). Similarly, MVD was increased significantly from NOM (3.53±5.17) to LRED (27.57±12.25) to HRED (46.18±12.55) (p<0.0001). The expression of α-SMA was significantly increased from LRED (0.21±0.41) to HRED (1.13±0.56) (<0.0001). The Ki67 LI and α-SMA; MVD and α-SMA; and Ki67Ki67 LI and MVD in NOM, LRED and HRED showed a statistically significant positive correlation (P<0.0001). The increase in Ki67 LI was directly proportional to MVD and α-SMA expression from NOM to LRED to HRED (P<0.0001). The connective tissue stroma of NOM lacks α-SMA expression. Mild myofibroblast expression was noted in 4 cases of LRED (14.28%) and in 18 cases of HRED (81.81%). Moderate expression was noted only in 4 cases of HRED (22.22%).

Conclusion

Ki67 LI, CD105, and α-SMA expression showed significant differences between normal, LRED and HRED. These findings further support that features such as increased basal cell layer hyperplasia, abnormal superficial mitosis, increased nuclear-cytoplasmic ratio, and hyperchromasia could be transformation-relevant dysplastic features.

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.