Loss of oral mucosal stem cell markers in oral submucous fibrosis and their reactivation in malignant transformation

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.

Exosomal miR-17-5p derived from epithelial cells is involved in aberrant epithelium-fibroblast crosstalk and induces the development of oral submucosal fibrosis

Oral submucous fibrosis (OSF) is a chronic and inflammatory mucosal disease caused by betel quid chewing, which belongs to oral potentially malignant disorders. Abnormal fibroblast differentiation leading to disordered collagen metabolism is the core process underlying OSF development. The epithelium, which is the first line of defense against the external environment, can convert external signals into pathological signals and participate in the remodeling of the fibrotic microenvironment. However, the specific mechanisms by which the epithelium drives fibroblast differentiation remain unclear. In this study, we found that Arecoline-exposed epithelium communicated with the fibrotic microenvironment by secreting exosomes. MiR-17-5p was encapsulated in epithelial cell-derived exosomes and absorbed by fibroblasts, where it promoted cell secretion, contraction, migration and fibrogenic marker (α-SMA and collagen type I) expression. The underlying molecular mechanism involved miR-17-5p targeting Smad7 and suppressing the degradation of TGF-β receptor 1 (TGFBR1) through the E3 ubiquitination ligase WWP1, thus facilitating downstream TGF-β pathway signaling. Treatment of fibroblasts with an inhibitor of miR-17-5p reversed the contraction and migration phenotypes induced by epithelial-derived exosomes. Exosomal miR-17-5p was confirmed to function as a key regulator of the phenotypic transformation of fibroblasts. In conclusion, we demonstrated that Arecoline triggers aberrant epithelium-fibroblast crosstalk and identified that epithelial cell-derived miR-17-5p mediates fibroblast differentiation through the classical TGF-β fibrotic pathway, which provided a new perspective and strategy for the diagnosis and treatment of OSF.

DPSCs regulate epithelial-T cell interactions in oral submucous fibrosis

BACKGROUND

Oral submucous fibrosis (OSF) is a precancerous lesion characterized by fibrous tissue deposition, the incidence of which correlates positively with the frequency of betel nut chewing. Prolonged betel nut chewing can damage the integrity of the oral mucosal epithelium, leading to chronic inflammation and local immunological derangement. However, currently, the underlying cellular events driving fibrogenesis and dysfunction are incompletely understood, such that OSF has few treatment options with limited therapeutic effectiveness. Dental pulp stem cells (DPSCs) have been recognized for their anti-inflammatory and anti-fibrosis capabilities, making them promising candidates to treat a range of immune, inflammatory, and fibrotic diseases. However, the application of DPSCs in OSF is inconclusive. Therefore, this study aimed to explore the pathogenic mechanism of OSF and, based on this, to explore new treatment options.

METHODS

A human cell atlas of oral mucosal tissues was compiled using single-cell RNA sequencing to delve into the underlying mechanisms. Epithelial cells were reclustered to observe the heterogeneity of OSF epithelial cells and their communication with immune cells. The results were validated in vitro, in clinicopathological sections, and in animal models. In vivo, the therapeutic effect and mechanism of DPSCs were characterized by histological staining, immunohistochemical staining, scanning electron microscopy, and atomic force microscopy.

RESULTS

A unique epithelial cell population, Epi1.2, with proinflammatory and profibrotic functions, was predominantly found in OSF. Epi1.2 cells also induced the fibrotic process in fibroblasts by interacting with T cells through receptor-ligand crosstalk between macrophage migration inhibitory factor (MIF)-CD74 and C-X-C motif chemokine receptor 4 (CXCR4). Furthermore, we developed OSF animal models and simulated the clinical local injection process in the rat buccal mucosa using DPSCs to assess their therapeutic impact and mechanism. In the OSF rat model, DPSCs demonstrated superior therapeutic effects compared with the positive control (glucocorticoids), including reducing collagen deposition and promoting blood vessel regeneration. DPSCs mediated immune homeostasis primarily by regulating the numbers of KRT19 + MIF + epithelial cells and via epithelial-stromal crosstalk.

CONCLUSIONS

Given the current ambiguity surrounding the cause of OSF and the limited treatment options available, our study reveals that epithelial cells and their crosstalk with T cells play an important role in the mechanism of OSF and suggests the therapeutic promise of DPSCs.

The role of epithelial cells in fibrosis: Mechanisms and treatment

Fibrosis is a pathological process that affects multiple organs and is considered one of the major causes of morbidity and mortality in multiple diseases, resulting in an enormous disease burden. Current studies have focused on fibroblasts and myofibroblasts, which directly lead to imbalance in generation and degradation of extracellular matrix (ECM). In recent years, an increasing number of studies have focused on the role of epithelial cells in fibrosis. In some cases, epithelial cells are first exposed to external physicochemical stimuli that may directly drive collagen accumulation in the mesenchyme. In other cases, the source of stimulation is mainly immune cells and some cytokines, and epithelial cells are similarly altered in the process. In this review, we will focus on the multiple dynamic alterations involved in epithelial cells after injury and during fibrogenesis, discuss the association among them, and summarize some therapies targeting changed epithelial cells. Especially, epithelial mesenchymal transition (EMT) is the key central step, which is closely linked to other biological behaviors. Meanwhile, we think studies on disruption of epithelial barrier, epithelial cell death and altered basal stem cell populations and stemness in fibrosis are not appreciated. We believe that therapies targeted epithelial cells can prevent the progress of fibrosis, but not reverse it. The epithelial cell targeting therapies will provide a wonderful preventive and delaying action.

Spatial Transcriptomic and Metabolomic Landscapes of Oral Submucous Fibrosis-Derived Oral Squamous Cell Carcinoma and its Tumor Microenvironment

In South and Southeast Asia, the habit of chewing betel nuts is prevalent, which leads to oral submucous fibrosis (OSF). OSF is a well-established precancerous lesion, and a portion of OSF cases eventually progress to oral squamous cell carcinoma (OSCC). However, the specific molecular mechanisms underlying the malignant transformation of OSCC from OSF are poorly understood. In this study, the leading-edge techniques of Spatial Transcriptomics (ST) and Spatial Metabolomics (SM) are integrated to obtain spatial location information of cancer cells, fibroblasts, and immune cells, as well as the transcriptomic and metabolomic landscapes in OSF-derived OSCC tissues. This work reveals for the first time that some OSF-derived OSCC cells undergo partial epithelial-mesenchymal transition (pEMT) within the in situ carcinoma (ISC) region, eventually acquiring fibroblast-like phenotypes and participating in collagen deposition. Complex interactions among epithelial cells, fibroblasts, and immune cells in the tumor microenvironment are demonstrated. Most importantly, significant metabolic reprogramming in OSF-derived OSCC, including abnormal polyamine metabolism, potentially playing a pivotal role in promoting tumorigenesis and immune evasion is discovered. The ST and SM data in this study shed new light on deciphering the mechanisms of OSF-derived OSCC. The work also offers invaluable clues for the prevention and treatment of OSCC.

Role and new insights of microfibrillar-associated protein 4 in fibrotic diseases

Fibrosis is one of the most worrisome complications of chronic inflammatory diseases, leading to tissue damage, organ failure, and ultimately, death. The most notable pathological characteristic of fibrosis is the excessive accumulation of extracellular matrix (ECM) components such as collagen and fibronectin adjacent to foci of inflammation or damage. The human microfibrillar-associated protein 4 (MFAP4), an important member of the superfamily of fibrinogen-related proteins, is considered to have an extremely important role in ECM transformation of fibrogenesis. This review summarizes the structure, characteristics, and physiological functions of MFAP4 and the importance of MFAP4 in various fibrotic diseases. Meanwhile, we elaborated the underlying actions and mechanisms of MFAP4 in the development of fibrosis, suggesting that a better understand of MFAP4 broadens novel perspective for early screening, diagnosis, prognostic risk assessment, and treatment of fibrotic diseases.

The interplay of EMT and stemness driving malignant transformation of Oral Submucous Fibrosis

Background

Oral submucous fibrosis (OSF) is a persistent oral mucosal condition that carries an elevated risk of undergoing malignant transformation. Our objective was to elucidate the involvement of epithelial-to-mesenchymal transition (EMT) in OSF and its progression to malignancy by studying a panel of EMT markers, thereby understanding the molecular mechanisms.

Methods

An immunohistochemical analysis was done to detect the presence of E-cadherin, N-cadherin, pan-cytokeratin (PanCK), vimentin, α-SMA (alpha-smooth muscle actin), and CD44 in a total of 100 tissue samples. These samples comprised 40 cases of OSF, 20 cases of oral squamous cell carcinoma associated with OSF (OSFSCC), and 40 cases of oral squamous cell carcinoma (OSCC). A whole transcriptomic analysis was performed on a group of seven matched samples encompassing NOM, OSF, OSFSCC, and OSCC.

Results

We observed significantly decreased expression of E-cadherin and PanCK, while N-cadherin, vimentin, α-SMA, and CD44 showed significantly higher expression in OSFSCC and OSCC as compared to OSF, both at protein and RNA levels. CD44 expression was noticeably higher in OSFSCC (p < 0.001) than in OSCC.

Conclusion

Downregulation of epithelial markers with concomitant upregulation of mesenchymal and stem cell markers suggests the potential role of EMT and stemness in accelerating the pathogenesis and malignant transformation of OSF. The high levels of CD44 expression seen in OSFSCC indicate a high propensity for aggressiveness and acquisition of stem-like characteristics by the cells undergoing EMT.

Senescence-associated secretory phenotypes in mesenchymal cells contribute to cytotoxic immune response in oral lichen planus

Oral lichen planus is a chronic inflammatory condition that adversely affects the oral mucosa; however, its etiology remains elusive. Consequently, therapeutic interventions for oral lichen planus are limited to symptomatic management. This study provides evidence of the accumulation of senescent mesenchymal cells, CD8 + T cells, and natural killer cells in patients with oral lichen planus. We profiled the patients' tissues using the National Center for Biotechnology Information Gene Expression Omnibus database and found that senescence-related genes were upregulated in these tissues by gene set enrichment analysis. Immunohistochemical analysis showed increased senescent mesenchymal cells in the subepithelial layer of patients with oral lichen planus. Single-cell RNA-seq data retrieved from the Gene Expression Omnibus database of patients with oral lichen planus revealed that mesenchymal cells were marked by the upregulation of senescence-related genes. Cell-cell communication analysis using CellChat showed that senescent mesenchymal cells significantly influenced CD8 + T cells and natural killer cells via CXCL12-CXCR4 signaling, which is known to activate and recruit CD8 + T cells and NK cells. Finally, in vitro assays demonstrated that the secretion of senescence-associated factors from mesenchymal cells stimulated the activation of T cells and natural killer cells and promoted epithelial cell senescence and cytotoxicity. These findings suggest that the accumulation of mesenchymal cells with senescence-associated secretory phenotype may be a key driver of oral lichen planus pathogenesis.

Conceptual model for progression of oral cancer - our perspective

Oral cancer was and still is an underestimated disease in terms of incidence and mortality rates. As a result, requires early detection and urgent prevention. This article describes a framework that covers the significant stages of conceptual development of oral cancer. Conceptual model is useful in understanding the pathogenesis and understand the disease processes. This article signifies information on various aspects of perspective risk and the role played by it. Article covers the following aspects: what are the perspective risks, what changes it causes to normal cell, what are the direct and indirect effects on normal cell, cellular changes seen with normal cell when affected with perspective risk, transformation of normal cell to oral potentially malignant disorders (OPMD) and changes seen during transformation into cancer. Understanding the conceptual model of oral cancer transformation will be a paradigm shift in future research in the field and early management of oral cancer, which will reduce the disease burden on the nation.

Comparison of the IHC Markers CD138 and CD43 in Oral Leukoplakia: An Original Research

Background

In the clinical practice, one of the most common suspicious lesions that may be potentially malignant is oral leukoplakia. Globally, the rate at which it turns malignant varies. This study examines the levels of markers CD138 and 43 in oral leukoplakia.

Materials and Methods

Twenty archival blocks of confirmed epithelial dysplasia were taken from the Department of Oral Pathology. These were processed for the identification of markers CD138 and 43 through Immuno Histo Chemistry (IHC). The blocks were divided equally for both the markers.

Results

There was a noticeable difference in staining intensity between dysplastic tissue and nondysplastic epithelium. However, CD138 expression was low or weak in dysplastic epithelium. CD43 expression was negative in all nonhematopoietic tissues.

Conclusion

Genes that are cancer associated have been found to have incredibly different impacts in numerous tissues during the multistep process of oral carcinogenesis. In tissues undergoing dysplastic changes, CD138 expression was shown to be decreased, which could point out the malignant changes initiated in the epithelium of the oral tissues.

Can precancerous stem cells be risk markers for malignant transformation in the oral mucosa?

Accurate assessment of the carcinogenic potential of oral mucosal diseases can significantly reduce the prevalence of oral cancer. We speculate that precancerous stem cells (pCSCs) arise during the evolution of carcinomas based on long-term experimental findings, published literature, and the cancer stem cell (CSC) theory, wherein pCSCs exist in precancerous lesions and have characteristics of both CSCs and normal stem cells. This apparently contradictory feature may be the foundation of the reversible transformation of precancerous lesions. Predicting malignant transformation in potentially malignant oral illnesses would allow for focused treatment, prognosis, and secondary prevention. Currently available clinical assays for chromosomal instability and DNA aneuploidy have several deficiencies. We hope that our study will increase attention to pCSC research and lead to the development of novel strategies for the prevention and treatment of oral cancer by identifying pCSC markers.

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.

IRF4 as a novel target involved in malignant transformation of oral submucous fibrosis into oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) in the context of oral submucous fibrosis (OSF) has a high incidence owing to undefined pathogenesis. Identifying key genes and exploring the underlying molecular mechanisms involved in the conversion of OSF into OSCC are in urgent need. Differentially expressed genes (DEGs) between OSCC and OSF were dug from GEO databases and a total of 170 DEGs were acquired. Functional association of DEGs were analyzed by GO and KEGG. Protein-protein interactions (PPIs) analysis was carried out and candidate biomarkers were identified by Gene co-expression analysis and Cox analyses. Hub genes were confirmed by qRT-PCR in tissues and cell lines, of which we found that IRF4 mRNA was successively up-regulated from Normal to OSF and then to OSCC and associated with immune infiltrating levels. In addition, Immunohistochemical (IHC) and Immunofluorescence (IF) assays were conducted to validate the consistent upregulation of IRF4 and the oncogene role of IRF4 in OSF and OSCC at translation level. IRF4 may be indicative biomarker in transformation of OSF into OSCC. High IRF4 expression contribute to increased immune infiltration of OSCC and may provide a novel diagnostic marker for OSCC patients translated from OSF.

Study of MicroRNA (miR-221-3p, miR-133a-3p, and miR-9-5p) Expressions in Oral Submucous Fibrosis and Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is one of the common types of cancer. Its progression follows a transition from oral potentially malignant disorders (OPMDs) such as oral submucous fibrosis (OSMF). Epigenetic modifiers, especially microRNAs (miRNAs), have an appreciable role in the regulation of various carcinogenic pathways which are being used as biomarkers. miRNAs may also be helpful in the differentiation of oral submucous fibrosis from oral squamous cell carcinoma. Three miRNAs, miR-221-3p, miR133a-3p, and miR-9-5p, were found differentially expressed in many cancers in the literature search supported by our preliminary database search-based screening. The literature and our functional enrichment analysis in an earlier study have reported these miRNAs to regulate carcinogenesis at various steps. In the present study, the expression of these miRNAs was examined in 34 histopathologically confirmed OSCC, 30 OSMF, and 29 control (healthy volunteers) human samples. There was a significant downregulation of miRNA-133a-3p in OSCC compared to OSMF and controls, whereas there was up-regulation in oral submucous fibrosis compared to controls. There was no significant difference in the expression of miR-221-3p between OSCC and OSMF, but an upregulation in OSCC compared to controls. miR-9-5p was also found upregulated in both OSCC and OSMF. Further, miR-133a-3p expression was negatively correlated with age, smoking, drinking status, and AJCC staging, whereas miR-9-5p expression was only positively associated with tobacco/ areca nut chewing. The ROC plots, logistic regression model generated, and the correlation between the expression of miR-9-5p and miR-133a-3p in blood and tissue suggests that these could be used as risk stratification biomarkers.

Identification of a BRAF/PA28γ/MEK1 signaling axis and its role in epithelial-mesenchymal transition in oral submucous fibrosis

Oral submucous fibrosis (OSF) is a chronic and insidious oral potentially malignant disorder associated with a 4-17% risk of oral squamous cell carcinoma (OSCC). Our previous study found that proteasomal activator 28 gamma (PA28γ) is frequently overexpressed in oral squamous cell carcinoma and negatively correlated with poor patient prognosis. However, the role of PA28γ in the occurrence and development of OSF remains unclear. Here, we screened PA28γ-related genes and investigated their function in OSF. We demonstrated that the expression of PA28γ was positively associated with MEK1 and gradually elevated from normal to progressive stages of OSF tissue. Arecoline, a pathogenic component of OSF, could upregulate the protein levels of PA28γ and phosphorylated MEK1 and contribute to epithelial to mesenchymal transition (EMT) in epithelial cells. Notably, PA28γ could interact with MEK1 and upregulate its phosphorylation level. Furthermore, arecoline upregulated BRAF, which can interact with PA28γ and upregulate its protein level. Additionally, BRAF, PA28γ, and MEK1 could form protein complexes and then enhance the MEK1/ERK signaling pathways. The concrete mechanism of the protein stability of PA28γ is that BRAF mediates its degradation by inhibiting its ubiquitination. These findings underscore the instrumental role of PA28γ in the BRAF/MEK1 pathway and enhanced EMT through MEK1/ERK activation in OSF.

A biochemical research focused on the association of the levels of oxidative stress and nitric oxide with premalignant disorders and oral squamous cell carcinoma

CONTEXT

The reactive oxygen species such as superoxide radicals (O2 •), hydroxyl radicals (OH•), and hydrogen peroxide play a vital role in the pathogenesis of human cancer development and have become one of the areas of key interest in the field of biochemical analysis.

AIMS

The present study was designed to determine the significance of oxidative stress and levels of nitric oxide (NO) in patients with premalignant disorders and oral squamous cell carcinoma (OSCC), by evaluating the levels of lipid peroxidation products, antioxidants, and NO products.

SETTINGS AND DESIGN

The present study was conducted on 280 patients for 2 years. These patients were divided into 4 groups, Group I (n = 70, control), Group II (n = 70, oral submucous fibrosis), Group III (n = 70, OSCC), and Group IV (n = 70, OL).

SUBJECTS AND METHODS

The levels of lipid peroxidation products, antioxidants, and NO products were determined by colorimetric methods.

STATISTICAL ANALYSIS USED

Paired t-test was used to compare the mean.

RESULTS

Lipid peroxidation products such as lipid hydroperoxide and malondialdehyde and NO products such as nitrite (NO2-), nitrate (NO3-), and total nitrite (TNO2-) were significantly elevated, whereas enzymatic and nonenzymatic antioxidants were significantly lowered in OSCC, oral submucous fibrosis, and oral leukoplakia when compared to normal healthy participants. The P values were calculated and came as statistically significant (<0.05).

CONCLUSIONS

Antioxidant enzyme impairment and NO status may be considered as one of the factors responsible for oral cancer pathogenesis and may serve as a promising biomarker and therapeutic target for minimizing malignant transformation in oral premalignant disorders.

Oral Senescence: From Molecular Biology to Clinical Research

Cellular senescence is an irreversible cell cycle arrest occurring following multiple rounds of cell division (replicative senescence) or in response to cellular stresses such as ionizing radiation, signaling imbalances and oxidative damage (stress-induced premature senescence). Even very small numbers of senescent cells can be deleterious and there is evidence that senescent cells are instrumental in a number of oral pathologies including cancer, oral sub mucous fibrosis and the side effects of cancer therapy. In addition, senescent cells are present and possibly important in periodontal disease and other chronic inflammatory conditions of the oral cavity. However, senescence is a double-edged sword because although it operates as a suppressor of malignancy in pre-malignant epithelia, senescent cells in the neoplastic environment promote tumor growth and progression. Many of the effects of senescent cells are dependent on the secretion of an array of diverse therapeutically targetable proteins known as the senescence-associated secretory phenotype. However, as senescence may have beneficial roles in wound repair, preventing fibrosis and stem cell activation the clinical exploitation of senescent cells is not straightforward. Here, we discuss biological mechanisms of senescence and we review the current approaches to target senescent cells therapeutically, including senostatics and senolytics which are entering clinical trials.

Functional and Therapeutic Significance of Tumor-Associated Macrophages in Colorectal Cancer

The role of the tumor microenvironment (TME) in the progression of colorectal cancer (CRC) and its acquisition of resistance to treatment become the research hotspots. As an important component of TME, the tumor-associated macrophages (TAMs) regulate multiple critical oncogenic processes, namely, occurrence, proliferation, metastasis, and drug resistance in CRC. In this review, we have discussed the functional and therapeutic significance of TAMs in CRC. M1 macrophages act as the tumor suppressor while M2 macrophages promote CRC. The polarization of TAMs is mainly regulated by the pathways such as NFKB1 pathways, STAT3 pathways, WNT5A pathways, and PI3K pathways in CRC. Furthermore, the M2 polarization of TAMs is not only controllable but also reversible. Finally, we provide insights into the TAMs-targeted therapeutic strategies.

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.

Molecular Mechanisms of Malignant Transformation of Oral Submucous Fibrosis by Different Betel Quid Constituents-Does Fibroblast Senescence Play a Role?

Betel quid (BQ) is a package of mixed constituents that is chewed by more than 600 million people worldwide, particularly in Asia. The formulation of BQ depends on a variety of factors but typically includes areca nut, betel leaf, and slaked lime and may or may not contain tobacco. BQ chewing is strongly associated with the development of potentially malignant and malignant diseases of the mouth such as oral submucous fibrosis (OSMF) and oral squamous cell carcinoma (OSCC), respectively. We have shown recently that the constituents of BQ vary geographically and that the capacity to induce disease reflects the distinct chemical composition of the BQ. In this review, we examined the diverse chemical constituents of BQ and their putative role in oral carcinogenesis. Four major areca alkaloids—arecoline, arecaidine, guvacoline and guvacine—together with the polyphenols, were identified as being potentially involved in oral carcinogenesis. Further, we propose that fibroblast senescence, which is induced by certain BQ components, may be a key driver of tumour progression in OSMF and OSCC. Our study emphasizes that the characterization of the detrimental or protective effects of specific BQ ingredients may facilitate the development of targeted BQ formulations to prevent and/or treat potentially malignant oral disorders and oral cancer in BQ users.

Dissolvable and layered microneedles composed of hyaluronate/rbFGF/CPC effectively improve the treatment effect on recurrent aphthous ulcers

Conventional topical medications for recurrent aphthous ulcers (RAU) are limited due to the washing effects of saliva and activities of masticatory muscle decreasing the local effective drug concentration. To overcome...

Interferon-inducible protein, IFIX, has tumor-suppressive effects in oral squamous cell carcinoma

IFIX, a newly discovered member of the interferon-inducible HIN-200 family, has been identified as a tumor suppressor in breast cancer; however, the involvement of IFIX in oral cancer are poorly understood. Here, we demonstrate a relationship between the level of IFIX expression and the invasive or migratory abilities of oral squamous cell carcinoma. Higher IFIX expression significantly correlated with clinicopathological parameters such as the histopathological grade of clinical samples. In vitro, IFIX overexpression suppressed the invasiveness of human tongue squamous cell carcinoma CAL-27 cells, and this inhibitory effect was mediated by stabilization of the cytoskeleton through various cytokeratins along with downregulation of paxillin, an intracellular adaptor protein that promotes tumor invasion. This inhibitory effect does not appear to affect the transformation of cancer stem-like cells in this cell culture model. Altogether, these data provide novel insights into the tumor-suppressive function of IFIX, namely, stabilization of the cancer cell cytoskeleton.

Collagen deposition correlates with loss of E-cadherin and increased p63 expression in dysplastic conditions of oral submucous fibrosis

This paper focuses on the status of epithelial markers, E-cadherin, and p63 in the backdrop of an abnormal amount of collagen in the sub-mucosa of dysplastic and non-dysplastic grades of OSF. Histologically confirmed OSF and normal oral mucosa samples were procured. Samples were stained by Van Gieson's stain (VG) and immunohistochemistry. The captured images were analyzed by ImageJ software to quantify their grayscale intensities. There was a gradual increase in the intensity of VG stain from normal to non-dysplastic and dysplastic OSF and the differences in their mean grayscale values were found to be significant (p < 0.00001). The intensity of E-cadherin was found to be the highest in non-dysplastic conditions and lowest in dysplastic conditions. The intensity difference of E-cadherin between normal and non-dysplastic OSF was found to be significant (p < 0.00001). The grayscale scale intensity values for p63 in whole epithelium depicted significant differences between normal and diseased conditions but for its intensity, in basal cells, significant differences were found between non-dysplastic and other classes of tissues. There was a positive correlation observed between VG and p63 staining intensity. The diseased oral epithelium demonstrated greater deposition of sub-epithelial collagen fibers along with subsequent loss of E-cadherin and an increased p63 expression.

A contemporary narrative review to guide molecular epidemiology of oral submucous fibrosis

Oral submucous Fibrosis (OSMF) is a chronic disease that mainly affects the upper part of the aerodigestive tract. Areca nut and betel quid chewing has been established as the most significant causative factor for this condition. While OSMF is a predominantly Asian disease, the migrant populations from the region have taken the disease across the globe. Additionally, areca nut is now easily accessible in flavors and aggressively marketed. Many research activities have been undertaken for decades to understand the etiopathogenesis and risk factors of OSMF. Although OSMF is a slowly progressing disease, it has the potential to transform to an oral malignancy. This article is an attempt to review the literature and provide an update on its prevalence, etiopthogenesis and its diagnosis. We also highlight certain clinical, histopathological and molecular features that aid in the diagnosis and prognostication of OSMF, highlighting the importance of identifying the possibly high risk OSMF that is prone to malignant transformation. Using this information, future directions can be developed to include treatmentof OSMF through a dynamic gene-specific approach.

Emerging role of cellular senescence in the pathogenesis of oral submucous fibrosis and its malignant transformation

Senescence is a common denominator in wound healing, fibrosis, and cancer. Although, senescence is transiently antifibrotic, when prolonged, promotes fibrosis and malignant transformation. Eligible studies indexed in MEDLINE, Embase and Web of Science were searched to understand the role of cellular senescence in the pathogenesis of oral submucous fibrosis (OSF) and its malignant transformation. The senescence-associated secretory phenotype (SASP) components like IL-1, IL-6, and GRO-α induce double-strand DNA breaks in keratinocytes and drive genetic instability. SASP derived from myofibroblasts induces epithelial-mesenchymal transition in OSF and facilitates cancer progression. The use of senolytics has been shown to eliminate senescent cells from the areas of fibrosis, thereby preventing malignancy. Naturally occurring agents such as apigenin and kaempferol inhibit SASP. Mechanistic insight into the emerging role of senescence in the pathogenesis of OSF and modalities to inhibit senescence-associated antiapoptotic pathways as a supplementary therapy to prevent malignant transformation of OSF is underlined.

Role of Yes-associated protein and transcriptional coactivator with PDZ-binding motif in the malignant transformation of oral submucous fibrosis

OBJECTIVE(S)

The objective of the present manuscript is to elucidate the role of matrix stiffness in the malignant transformation of oral submucous fibrosis.

DESIGN

The role of matrix stiffness in several cancers including oral cancer was reviewed with a tailored search strategy using relevant keywords as per the Medline format. The role of molecular mediators, Yes-associated protein 1 (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) was weighed in the context of OSF along two distinct pathways.

RESULTS

Increased matrix stiffness activates the transcriptional coactivators, YAP and TAZ shuttling between the nucleus and cytoplasm. YAP and TAZ, serve as mechanical transducers in promoting cell migration, invasion and epithelial-mesenchymal transition (EMT). The hypoxic microenvironment in the advanced stage of OSF promotes the migratory phenotype through mechanical memory.

CONCLUSIONS

Reprogramming of a stiff matrix has the potential to restore the Hippo-YAP/TAZ tumor suppressor pathway and reverse fibrosis-associated tumor development.