Proliferative ability and accumulation of cancer stem cells in oral submucous fibrosis epithelium

Role of Stem Cells in the Pathogenesis and Malignant Transformation of Oral Submucous Fibrosis

BACKGROUND

Pathogenesis and malignant potential of Oral submucous fibrosis(OSMF) have always been a topic of interest among the researchers. Despite OSMF being a collagen metabolic disorder, the alterations occurring in the connective tissue stroma affects the atrophic surface epithelium in later stages and progresses to malignant phenotypes. The present review aims to summarize the role of stem cells in the pathogenesis and malignant transformation of oral submucous fibrosis.

MATERIALS AND METHODS

A literature search was carried out using data banks like Medline and Embase, google scholar and manual method with no time frame, pertinent to the role of mucosal stem cells in OSMF and its malignisation. The relevant literature was reviewed, critically appraised by all the authors and compiled in this narrative review.

RESULTS

Critical appraisal and evaluation of the data extracted from the selected articles were compiled in this review. The collated results highlighted the upregulation and downregulation of various stem cell markers during the progression and malignisation of OSMF were depicted in a descriptive and detail manner in the present review.

CONCLUSION

We highlight the potential of mucosal stem cells in the regulation and malignisation of OSMF. However, future large-scale clinical studies will be needed to support whether manipulation of this stem cells at molecular level will be sufficient for the treatment and preventing the malignant transformation of OSMF.

A Case of Advanced Oral Submucous Fibrosis Management: Beyond Conventional Approach

A chronic, persistent, possibly cancerous condition that mostly affects the oral cavity is called oral submucous fibrosis (OSMF) and causes severe functional impairment. Due to its complex nature, OSMF requires a comprehensive strategy that includes both surgical and medication therapies. Multidisciplinary treatment was started, which included a complete stoppage of habit, dental hygiene precautions, dietary counselling, surgical intervention, supportive medicinal therapy, and physiotherapy. Following surgery and adjunct therapy, the patient's mouth opening and functional results were improved. The patient is kept for regular follow-up to assess the recurrence of fibrosis or any incidence of malignant transformation. This case emphasizes the difficulties in treating advanced OSMF and emphasizes how crucial it is to improve patient outcomes by early detection, stopping betel nut chewing, and thorough multidisciplinary care.

Mechanisms and markers of malignant transformation of oral submucous fibrosis

Oral submucous fibrosis (OSF) is a chronic premalignant disease associated with betel quid chewing. Epidemiological studies indicate that there are approximately 5 million individuals suffering from OSF worldwide, with a concerning malignancy transformation rate of up to 4.2 %. When OSF progresses to oral squamous cell carcinoma (OSCC), the 5-year survival rate for OSCC drops to below 60 %. Therefore, early screening and diagnosis are essential for both preventing and effectively treating OSF and its potential malignant transformation. Numerous studies have shown that the malignant transformation of OSF is associated with various factors, including epigenetic reprogramming, epithelial-mesenchymal transition, hypoxia, cell cycle changes, immune regulation disturbances, and oxidative damage. This review article focuses on the unraveling the potential mechanisms underlying the malignant transformation of OSF, as well as the abnormal expression of biomarkers throughout this transformative process, with the aim of aiding early screening for carcinogenic changes in OSF. Furthermore, we discuss the significance of utilizing blood and saliva components from patients with OSF, along with optical diagnostic techniques, in the early screening of OSF malignant transformation.

A Critical Interpretive Synthesis of the Role of Arecoline in Oral Carcinogenesis: Is the Local Cholinergic Axis a Missing Link in Disease Pathophysiology?

Arecoline is the primary active carcinogen found in areca nut and has been implicated in the pathogenesis of oral squamous cell carcinoma (OSCC) and oral submucous fibrosis (OSF). For this study, we conducted a stepwise review process by combining iterative scoping reviews with a post hoc search, with the aim of identifying the specific mechanisms by which arecoline initiates and promotes oral carcinogenesis. Our initial search allowed us to define the current trends and patterns in the pathophysiology of arecoline-induced OSF and OSCC, which include the induction of cell proliferation, facilitation of invasion, adhesion, and migration, increased collagen deposition and fibrosis, imbalance in immune and inflammatory mechanisms, and genotoxicity. Key molecular pathways comprise the activation of NOTCH1, MYC, PRDX2, WNT, CYR61, EGFR/Pl3K, DDR1 signaling, and cytokine upregulation. Despite providing a comprehensive overview of potential pathogenic mechanisms of OSF, the involvement of molecules functioning as areca alkaloid receptors, namely, the muscarinic and nicotinic acetylcholine receptors (AChRs), was not elucidated with this approach. Accordingly, our search strategy was refined to reflect these evidence gaps. The results of the second round of reviews with the post hoc search highlighted that arecoline binds preferentially to muscarinic AChRs, which have been implicated in cancer. Consistently, AChRs activate the signaling pathways that partially overlap with those described in the context of arecoline-induced carcinogenesis. In summary, we used a theory-driven interpretive review methodology to inform, extend, and supplement the conventional systematic literature assessment workflow. On the one hand, the results of this critical interpretive synthesis highlighted the prevailing trends and enabled the consolidation of data pertaining to the molecular mechanisms involved in arecoline-induced carcinogenesis, and, on the other, brought up knowledge gaps related to the role of the local cholinergic axis in oral carcinogenesis, thus suggesting areas for further investigation.

Controversies in verruco papillary lesions of the oral cavity-A systematic review

INTRODUCTION

Verruco papillary lesions (VPL) in the oral cavity encompass a spectrum of lesions starting from benign, potentially malignant to entirely malignant tumors. Much of the controversies in these entities occur due to lack of consensus on the disease characteristics and the management. This systematic review was conducted to identify and describe different lesions categorized as VPL in the oral cavity and their association with malignancy.

METHODS

An electronic literature search was conducted in MEDLINE (via PubMed), Scopus, LILAC, IMSEAR, and CENTRAL databases, which retrieved a total of 1020 abstracts. These abstracts were managed through Rayyan and Mendeley software, and only 28 studies with high quality were included in the systematic review.

RESULTS

Studies were published from 1992 to 2021. From the extracted data, nine different entities under the umbrella term VPL were identified associated with malignancy. We describe the clinical and histopathological characteristics of these and propose a uniform framework for nomenclature.

CONCLUSIONS

Lack of well-planned research with adequate follow-up duration and inadequate quality standards are major barriers for the lack of evidence. The use of uniform nomenclature, as proposed in this study, and research at the molecular level will greatly reduce the controversies in understanding oral VPL associated with malignancy.

Immunohistochemical expression of SOX2 in OKC and ameloblastoma: A comparative study

Introduction

Odontogenic, non-inflammatory maxillofacial cysts and tumours vary greatly in their ability to grow and cause local tissue destruction. Despite their common embryologic origin, the biologic mechanisms responsible for this diverse array of clinical behaviour are largely unknown. Unfortunately, even with accurate tissue diagnosis and appropriate surgical management, these tumours have relatively high recurrence rates. While this may be related to surgical technique, it may also be due to intrinsic tumour biology. SOX2 is differentially expressed in odontogenic cysts and tumours, which has an impact over patient prognosis. This could be related to their diverse cells of origin or stages of histogenesis. SOX2 is expressed in OKC and ameloblastoma, and in this study, we look forward to find altered levels and intensity of SOX2 in the above-mentioned lesions.

Aim and Objectives

To profile the expression of SOX2 in odontogenic keratocyst (OKC) and ameloblastomaTo compare the intensity of these lesions, analyse their intrinsic feature and predict their recurrence.

Material and Methods

Histopathologically diagnosed cases of OKC and ameloblastoma will be selected (n = 40). Paraffin-embedded, formalin-fixed sections of these lesions will be stained for SOX2 marker using a standard immunohistochemical technique. Positive control will be taken as oral squamous cell carcinoma and negative control will be taken as normal oral mucosa.

Results

A comparison between the stained cell types in odontogenic keratocyst and ameloblastoma revealed statistically significant differences. The immunoreactivity scores of SOX2 were analysed in both groups. The results indicated that 45% of OKC cases exhibited strongly positive reactivity, while 65% of ameloblastoma cases were negative. Statistical analysis demonstrated highly significant differences in the frequency of SOX2 expression between the two groups, with a higher frequency of negative expression in ameloblastoma.

Conclusion

Stem cell markers have been observed in these lesions, suggesting the acquisition of stem-like properties by tumour cells, which can affect patient prognosis. Specifically, the marker SOX2 shows differential expression in odontogenic cysts and tumours. High expression of SOX2 in OKC indicates the presence of stem cells with significant self-renewal and proliferative properties, potentially signifying neoplastic behaviour. In contrast, weak or absent expression of SOX2 in ameloblastoma suggests different molecular pathways involved in its neoplastic behaviour.

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.

Effect of smoking on MUC1 expression in oral epithelial dysplasia, oral cancer, and irradiated oral epithelium

OBJECTIVES

The aim of this study was to assess the MUC1 expression in the oral epithelium of normal, oral epithelial dysplasia (OED), oral squamous cell carcinoma (OSCC), and irradiated oral epithelium (IROE) and its association with smoking habits in non-smokers and smokers.

DESIGN

Oral mucosal biopsies from controls, OED, OSCC, and IROE groups were obtained and categorized based on the smoking history as non-smokers, smoker I (25 pack-years), and smoker II (>25 pack-years). Immunohistochemical staining of MUC1 using human milk fat globule 1 (HMFG 1) antibody was performed, and the MUC1 score was calculated. The relation between MUC1 expression and clinicopathological findings was examined.

RESULTS

MUC1 staining of superficial oral epithelial cells with mild MUC1 score was detected in all control samples. The MUC1 staining extended from superficial to basal cell layer of oral epithelium with the increase in MUC1 score from moderate to strong in OED, OSCC, and IROE, and the difference was significant (p < 0.004, p < 0.002 and p < 0.004, respectively) compared to controls. A positive association between smoking and MUC1 score was observed within groups (p < 0.05).

CONCLUSION

The depolarization of MUC1 protein expression is associated with smoking habits in OED and OSCC. In the IROE, the radiation causes subcellular and molecular changes, observed as altered MUC1 expression and accelerated by smoking, furthermore, complicating the oral mucosal adaptation and progress to radiation-induced lesions as a delayed effect.

Immunohistochemical Biomarkers in Oral Submucous Fibrosis - A Scoping Review

INTRODUCTION

This scoping review was done to study the immunohistochemical biomarkers involved in pathogenesis and malignant transformation (MT) of oral submucous fibrosis (OSF), in literature published from 2010 to 2021.

METHOD

The protocol was adapted from the Joanna Briggs Institute Reviewer's Manual (2017, and reported according to the PRISMA guidelines for Scoping Reviews (PRISMA-ScR).

RESULTS

Eighty-six studies included in this review reported 84 immunohistochemical (IHC) biomarkers in OSF: 9 epithelial markers, 29 connective tissue markers, 22 proliferative markers, and 24 other biomarkers that are transcription factors, cancer stem cell markers, cell signaling markers, proteins, and enzymes. The commonly reported IHC biomarkers were alpha-smooth muscle actin (α-SMA) and E-cadherin (7 articles each) followed by vascular endothelial growth factor (VEGF) and CD34 (6 articles each), p53, p63 and Ki67 (5 articles each). α-SMA, Ki67, CD105, and hTERT were significantly increased in oral squamous cell carcinoma arising in a background of OSF (OSCC-OSF) compared to OSF and normal subjects.

CONCLUSION

The identified surrogate IHC biomarkers reported in OSF in this scoping review require validation with long-term prospective studies to facilitate early diagnosis, for use in risk assessment, and plan appropriate treatment for OSF in clinical practice.

Pathological investigations and correlation research of microfibrillar-associated protein 4 and tropoelastin in oral submucous fibrosis

Background

Oral submucous fibrosis (OSF), distinguished by abnormal collagen deposition, is a potentially malignant disorder with 4.2% (95% CI 2.7–5.6%) of malignant transformation and rising global prevalence. However, the precise pathogenesis and effective treatment remain elusive and controversial despite the abundance of literature on this topic. Therefore, it is crucial to explore the clinicopathological characteristics and potential markers for the diagnosis and prognosis of OSF. The objective of this study was to evaluate the influence and correlation of Microfibrillar-associated protein 4 (MFAP4) and tropoelastin (TE) in the development of OSF patients.

Material and methods

Clinicopathological factors, hematoxylin–eosin (HE) and Masson trichome staining, immunohistochemical characteristics and the correlation between MFAP4 and TE were recorded and compared among different stages of OSF progression among cases (n = 60) and controls (n = 10). Student's t test, ANOVA analysis, and the chi-square test were performed to compare the categorical variables for clinicopathological characteristics and the expression level of MFAP4 and TE between the fibrotic and normal tissues. Correlation analysis of MFAP4 and TE was performed using Pearson's correlation test and linear regression.

Results

MFAP4 and TE proteins are upregulated and increased gradually in patients with varying stages of OSF, relative to the control group. Furthermore, statistical analyses revealed that the expression level of MFAP4 was positively associated with TE, with a Pearson correlation coefficient of 0.3781 (p = 0.0048). Clinically, we found that OSF affected more males than females, with a ratio of 29:1. The age range was 16–60 years, and the mean age was 36.25 ± 10.25 years. In patients younger than 40 years, the positive expression rate of MFAP4 and TE was higher than in those over 40 years. All OSF cases had chewed areca nut, with 51.67% smoking tobacco.

Conclusions

Our study elucidates that the accumulation of MFAP4 and TE proteins may play a vital role in the occurrence and development of OSF and may be promising candidate moleculars for prevention, diagnosis, and treatment strategies for OSF in the future.