Progression Of Oral Submucous Fibrosis Research Articles

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

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. 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. 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). 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.

A Study to Assess the Role of Psychological Stress in the Severity of Oral Lichen Planus, OSMF, and Leukoplakia and its Correlation with Serum Cortisol Levels

ABSTRACT Introduction: The most prevalent oral mucosal conditions in humans are leukoplakia, oral lichen planus (OLP), and oral submucous fibrosis (OSMF). These conditions should be studied as psychosomatic conditions, but little research has been done on how these conditions relate to stress. Materials and Methods: A total of 280 patients of both genders with ages 35–60 years were divided into four groups: leukoplakia, OSMF, OLP, and control. Whole blood samples were collected from all the participants and analyzed for serum cortisol by using ELISA with a commercial kit. Detailed case history and DASS-21 questionnaire were recorded for psychological assessment. To assess the variables, the student t test and Chi-square test were used. P values of &lt;0.05 were regarded as significant. Results: In this study, it was found that higher levels of serum cortisol were found in OLP patients, with advanced erosive lesions showing the highest levels of serum cortisol, followed by OSMF and leukoplakia. Patients with Oral Lichen Planus showed higher levels of stress, anxiety and depression than patients of OSMF and leukoplakia. Conclusion: This study emphasized stress and anxiety as a predisposing factor in the occurrence and progression of OSMF apart from re-establishing the role of stress and anxiety in OLP with consideration to depression in triggering role for OLP. Furthermore, it demonstrated that serum cortisol levels play a significant role as an indicator of psychological stress.

Mechanism of adipose tissue-derived stromal cell-extracellular vesicles in treating oral submucous fibrosis by blocking the TGF-β1/Smad3 pathway via the miR-760-3p/IGF1R axis

Oral submucous fibrosis (OSF) is a prevalent chronic condition, and understanding its pathogenesis is crucial for developing effective therapeutic strategies. This study explores the potential of adipose tissue-derived stromal cell-extracellular vesicles (ADSC-EVs) in mitigating OSF and investigates the underlying molecular mechanisms. OSF was induced in mice by arecoline feeding. Adipose tissue-derived stromal cells (ADSCs), fibrotic buccal mucosal fibroblasts (fBMFs) isolated from OSF mice, and ADSC-EVs were comprehensively characterized. The treatment effects of extracellular vesicles (EVs) and pcDNA3.1-IGF1R on fBMF proliferation, migration, and invasion were assessed using Cell Counting Kit-8 (CCK-8) assay, transwell assay, and flow cytometry assay. The expression levels of alpha smooth muscle actin (α-SMA), collagen I, collagen III, and insulin-like growth factor 1 receptor (IGF1R) were evaluated by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot. The interaction between miR-760-3p and IGF1R was investigated. In fBMFs and OSF mice treated with a miR-760-3p inhibitor and/or EVs, the expression patterns of miR-760-3p, IGF1R, and proteins related to the TGF-β1/Smad3 pathway were determined. ADSC-EVs demonstrated the ability to upregulate miR-760-3p, impede cell proliferation, migration, and invasion, and reduce α-SMA, collagen I, and collagen III levels in fBMFs. The expression of miR-760-3p was diminished in ADSC-EVs treated with a miR-760-3p inhibitor. However, silencing miR-760-3p or overexpressing IGF1R partially counteracted the beneficial effects of ADSC-EVs on fBMF fibrosis. miR-760-3p directly targets IGF1R. Significantly, ADSC-EVs exert their suppressive effects on the TGF-β1/Smad3 pathway through the miR-760-3p/IGF1R axis. In summary, ADSC-EVs, by transferring miR-760-3p and inhibiting IGF1R expression, effectively block the TGF-β1/Smad3 pathway, thereby alleviating fibrosis in fBMFs and preventing the progression of OSF.

Biomarkers for assessing disease progression and treatment outcomes of oral submucous fibrosis

Biomarkers for assessing disease progression and treatment outcomes of oral submucous fibrosis (OSMF) have gained significant attention in recent years. This review provides an overview of the current research on biomarkers in OSMF and their potential implications in clinical practice. The review focuses on the different categories of biomarkers that have shown promise in assessing disease progression and treatment outcomes in OSMF. Epithelial dysplasia markers, including Ki-67, p53, and cyclin D1, are discussed in relation to dysplastic changes observed in OSMF. Inflammatory and immune markers, such as cytokines, chemokines, and inflammatory mediators, are explored for their role in OSMF progression. The dysregulation of extracellular matrix remodelling is highlighted, with a discussion on matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) as potential biomarkers. Furthermore, the review delves into biomarkers for treatment response and outcome prediction. Collagen turnover markers, including pro-collagen type I and MMPs, are examined as indicators of collagen synthesis and degradation. Oxidative stress markers, such as malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx), are evaluated for their ability to reflect oxidative stress and antioxidant status. The review also touches upon the potential of epigenetic markers, such as DNA methylation and histone modifications, in predicting treatment response and prognosis in OSMF. Additionally, the review explores the use of imaging techniques, including optical coherence tomography (OCT), autofluorescence imaging, and confocal microscopy, for assessing structural changes and biomarker expression in OSMF. It discusses the potential of molecular imaging modalities, such as positron emission tomography (PET) and molecular MRI, for visualizing specific biomarkers in OSMF. Moreover, the review highlights the importance of genomics approaches, including genomics, transcriptomics, proteomics, and metabolomics, in identifying novel biomarkers and unraveling molecular pathways in OSMF. We emphasize the potential of biomarkers in improving patient care and management in OSMF. It acknowledges the challenges in biomarker validation, standardization, and cost-effectiveness for widespread clinical use. The review calls for further research in emerging areas, such as non-coding RNAs, microRNA panels, and multi-modal biomarker approaches, to enhance our understanding of OSMF and facilitate personalized treatment strategies.

Senescent epithelial cells remodel the microenvironment for the progression of oral submucous fibrosis through secreting TGF-β1.

Cellular senescence is strongly associated with fibrosis and tumorigenesis. However, whether the epithelium of oral submucous fibrosis (OSF) undergoes premature senescence remains unclear. This study investigates the roles of senescent epithelial cells in OSF. The immunohistochemistry and Sudan black B staining were performed to identify epithelium senescence in OSF tissues. Arecoline was used to induce human oral keratinocytes (HOKs) senescence. The cell morphology, senescence-associated β galactosidase activity, cell counting Kit 8, immunofluorescence, quantitative real-time PCR, and western blot assay were used to identification of senescent HOKs. The enzyme-linked immunosorbent assay was exerted to evaluate the levels of transforming growth factor β1 (TGF-β1) in the supernatants of HOKs treated with or without arecoline. The senescence-associated markers, p16 and p21, were overexpressed in OSF epithelium. These expressions were correlated with alpha-smooth actin (α-SMA) positively and proliferating cell nuclear antigen (PCNA) negatively. Moreover, Sudan black staining showed that there was more lipofuscin in OSF epithelium. In vitro, HOKs treated with arecoline showed senescence-associated characteristics including enlarged and flattened morphology, senescence-associated β galactosidase staining, cell growth arrest, γH2A.X foci, upregulation of p53, p21, and TGF-β1 protein levels. Moreover, senescent HOKs secreted more TGF-β1. Senescent epithelial cells are involved in OSF progression and may become a promising target for OSF treatment.

Expression of transforming growth factor-β in oral submucous fibrosis: A systematic review.

Oral submucous fibrosis (OSF) is a potentially malignant disorder characterised by inflammation and progressive fibrosis. Transforming growth factor-β (TGF-β) has been established as a master regulator of fibrosis in various organs; however, lack of systematic review on expression of TGF-β and its isoforms in OSF restrict the understanding of their behaviour in its pathogenesis. Online electronic databases, such as PubMed Medline, Cochrane Library, Embase, and Scopus, were searched from their respective dates of inception till 31st March 2022. Human studies related to TGF-β expression in histopathologically diagnosed OSF cases, with or without malignant transformation, were included and assessed using a Cochrane risk of bias assessment tool: For non randomised studies of interventions (ACROBAT NRSI). The electronic literature search yielded 394 articles. Of those, ten articles met the inclusion criteria and involved total of 579 OSF patients. The risk of bias (RoB) was low to moderate. These studies demonstrated a significant positive expression of TGF-β and its isoforms in OSF compared to that in normal tissue samples. An increased pan TGF-β expression was observed in the early stages of OSF, and an increased expression of TGF-β1 and TGF-β2 were seen in advanced stages of OSF. Stage wise expression of TGF-β3 has not been discussed in the included studies. No significant relationship was observed between epithelial dysplasia and TGF-β expression in OSF. The distinct pattern in the expression of pan TGF-β, TGF-β1 and TGF-β2 in various stages of OSF indicates their different roles in OSF progression. We believe isoform targeted studies exploring stage wise expression of the marker will open new treatment avenues for OSF.

XIST/let-7i/HMGA1 axis maintains myofibroblasts activities in oral submucous fibrosis

Long non-coding RNA XIST promotes the development of various types of head and neck cancers, but its role in the progression of precancerous oral submucous fibrosis (OSF) has not been determined yet. As such, we aimed to examine whether XIST implicates in the regulation of myofibroblast activation. Our results showed that the expression of XIST was upregulated in OSF tissues and fibrotic buccal mucosal fibroblasts (fBMFs), and the silencing of XIST downregulated several myofibroblasts features. We demonstrated that elevation of let-7i after inhibition of XIST may lead to reduced myofibroblast activation. On the contrary, overexpression of high mobility group AT-Hook 1 (HMGA1) following the suppression of let-7i may result in enhanced myofibroblast activities. Moreover, we showed that the suppressive effect of silencing of XIST on myofibroblasts hallmarks was reversed by let-7i inhibition or HMGA1 overexpression, suggesting the pro-fibrotic property of XIST was mediated by downregulation of let-7i and upregulation of HMGA1. These findings revealed that myofibroblast activation of fBMFs may attribute to the alteration of the XIST/let-7i/HMGA1 axis. Therapeutic approaches to target this axis may serve as a promising direction to ameliorate the malignant progression of OSF.

Comparative Evaluation of Plasma Fibrinogen Degradation Product and Salivary Fibrin Precipitating Factor in Oral Submucous Fibrosis Patients and Betel Quid Chewers.

Estimation and correlation of plasma fibrinogen degradation product (FDP) and salivary fibrin precipitating factor (FPF) in oral sub mucous fibrosis (OSMF) patients, betel quid chewers without OSMF and healthy individuals. The study aims to evaluate whether FDP and FPF can be used as a marker for development and progression of OSMF and whether there is any correlation between the two. The study included 163 subjects grouped into three categories, Group 1, which included 54 control patients, Group 2, which included 55 betel quid chewers, and Group 3, which included 54 clinically confirmed OSMF patients. All of them were subjected to the estimation of plasma FDP and salivary FPF. FDP was present in 52 (96.3%) patients in Group 3, 2 (3.6%) patients in Group 2, and 1 patient in Group 1 (1.9%). FPF was positive in eight patients. The correlation of FDP and FPF was done by Fisher's exact test and was found to be statistically nonsignificant. In the present study, FDP was positive in 52 (96.3%) OSMF patients; hence, FDP may be used as an early indicator of OSMF. FDP was found to be positive in two patients with a habit of chewing betel quid without OSMF. It may be hypothesized that these patients are more likely to develop OSMF. Hence, the estimation of FDP may be used as a diagnostic test to predict an impending OSMF before it could manifest itself clinically. FPF was negative in some OSMF patients, may be because it is below the detectable range.

Potentiated action on the progression of OSMF by hypoxia mediated signaling pathway by the epithelial mesenchymal transition and angiogenic apparatus.

Epithelial-mesenchymal transition (EMT) is a complex process, in which epithelial cells acquire the characteristics of invasive mesenchymal cells. EMT has been implicated in cancer progression and metastasis as well as the formation of many tissues and organs during development. The aim of the study was to ascertain the role of hypoxia-mediated signaling pathways influencing EMT and angiogenesis in progression of oral submucous fibrosis (OSMF). Evaluation of the immunoexpression of alpha-smooth muscle actin (α-SMA), E-cadherin, vimentin, and factor VIII receptor antigen in OSMF and oral squamous cell carcinoma (OSCC) arising from OSMF was done. Differences between the different variables were analyzed using ANOVA test and Pearson's Chi-square test, and Mann-Whitney test was also calculated. The mean α-SMA positive myofibroblasts increased from Group 1 (OSMF) to Group 2 (OSCC), especially those in the deeper connective tissue stroma. The mean labeling index of vimentin and mean vessel density immunoexpression was more in Group 2 (OSCC) as compared to Group 1 (OSMF). Mean α-SMA correlated negatively with E-cadherin expression and positively with vimentin and factor VIII immunoexpression. E-cadherin expression correlated negatively with factor VIII and positively with Vimentin expression. The molecular mechanisms responsible for the development of OSCC in patients with OSMF require unification of multiple progressive pathogenetic mechanisms involved in the progression of the disease.

Mast cell expression in oral submucous fibrosis: A systematic review and metanalysis.

Oral submucous fibrosis (OSMF) is a chronic disorder associated with reduced mouth opening, burning sensation and listed as potentially malignant disorder. The role of mast cells in initiation and progression of this condition has been debated in last few years. It is imperative to understand the definitive role of mast cells and subsequently identify a possible cost-efficient treatment modality for OSMF. This review aimed to study the role of mast cells in OSMF by framing a research question that assessed the mast cell count (MCC), their degranulation and immunohistochemical analyses. We performed a comprehensive search of PubMed, EBSCOhost and general Google search that conceded 26 studies from which 15 articles were finalized for the review. The individual study syntheses revealed increased MCC in OSMF as compared to controls. Also, there was decreased MCC with the progression of OSMF. However, the metanalysis showed high level of heterogeneity as three studies out of eight studies found reduced MCC in disease when compared with controls. There is definite increase in mast cell in OSMF although the cell count falls with the advancement of OSMF. This increases the scope for further research to identify exact mechanism by which mast cells contribute to fibrosis and conduct the drug trials that can inhibit the mechanism. Key words:Oral submucous fibrosis, mast cell count, degranulated mast cells, stages of OSMF.Oral submucous fibrosis, mast cell count, degranulated mast cells, stages of OSMF.

Association of MICA gene Exon-5 polymorphism in oral submucous fibrosis

The present study was conducted to explore the allele frequencies of MICA gene Exon-5 transmembrane and to measure the circulatory MICA levels in various histologic grades of patients with oral submucous fibrosis (OSF) compared to healthy individuals. We enrolled a total of 595 patients for this cross-sectional study and divided them into 2 groups: healthy controls (n=320) and patients with OSF (n=275). Further, patients with OSF were subdivided based on their histologic gradings. The genomic DNA was extracted followed by a polymerase chain reaction and genotyping using the ABI Prism DNA Sequencer (ThermoFisher Scientific, Inc., Waltham, MA, USA). Our study showed that the A5 allele of the MICA gene in the Exon-5 region conferred significant risk for patients with OSF. With reference to the histologic gradings of OSF, we found that the MICA gene conferred statistically significant risk among patients with grade III OSF. On the other hand, the A8 allele of MICA gene in the Exon-5 region conferred significant protection among the overall OSF cohort and in the grade III of histologic grade. Finally, the circulatory human MICA levels were found to have a stepwise increase from grade I toward grade III in patients with OSF. Our results suggested that the A5 allele in MICA might confer risk for the progression of OSF among the South Indian ethnic population.

Low LINC02147 expression promotes the malignant progression of oral submucous fibrosis

BackgroundKey lncRNAs associated with the malignant progression of oral submucous fibrosis (OSF) to oral squamous cell carcinoma (OSCC) were identified.MethodsKey lncRNAs with sequential changes from normal oral mucosa (NOM) to OSF to OSCC were identified based on the GEO database. Kaplan–Meier analysis was used to screen lncRNAs related to OSCC prognosis. Cox regression analysis was used to validate the independent prognostic value. qPCR was used to confirm the expression of the candidate lncRNAs. Gene set enrichment analysis (GSEA), nucleocytoplasmic separation assay, fluorescence in situ hybridization, RNA knockdown, western blot, and cell viability assay were performed to investigate the biological functions of the candidate lncRNA. A nomogram was constructed to quantitatively predict OSCC prognosis based on TCGA.ResultsBioinformatics methods indicated that LINC02147 was sequentially downregulated from NOM to OSF to OSCC, as confirmed by clinical tissues and cells. Meanwhile, low LINC02147 expression, as an independent prognostic factor, predicted a poor prognosis for OSCC. GSEA and in vitro studies suggested that low LINC02147 expression promoted OSF malignant progression by promoting cell proliferation and differentiation. A LINC02147 signature-based nomogram successfully quantified each indicator’s contribution to the overall survival of OSCC.ConclusionsLow LINC02147 expression promoted OSF malignant progression and predicted poor OSCC prognosis.

Analysis of Expression of Myofibroblasts in Oral Submucous Fibrosis: An Immunohistochemistry Study

Background: Oral submucous fibrosis (OSMF) is a chronic disease that produces tissue fibrosis and is considered to be a potentially malignant disorder. The exact pathogenesis and malignant conversion mechanism of this disorder are still unknown. Myofibroblasts have been implicated as one of the possible pathological mechanisms responsible for the pathophysiology of OSMF. The present study was conducted to evaluate the expression of myofibroblasts (MF) in normal mucosa and different grades of OSMF. Materials &amp; Methods: The sample consisted of a total of 80 specimens. The study group included specimens from clinically and histopathologically confirmed OSMF patients. The specimens were divided into four groups. Group 1 consisted of 19 specimens of grade III OSMF. Group II had 20 specimens of grade II OSMF, Group 3 with 21 specimens of grade I OSMF, and Group 4 constituted a control group of 20 normal epithelium specimens. Two sections each from all the four groups were obtained. While one section was stained with H and E, the other section was stained immunohistochemically using α-smooth muscle antibody. For analysis, the expression of myofibroblasts was categorized as strong, moderate, weak, or absent. All the results were recorded and subjected to statistical analysis. Results: In OSMF patients, irrespective of the grade, the expression of myofibroblast was strong in 28.33 percent of the patients, while it was moderate and weak in 30.00 percent and 40.00 percent of the patients, respectively. Expression of myofibroblast was noted to be significantly increased in grade III OSMF patients as compared to controls as well as grade I OSMF patients (p-value &lt;0.05). Conclusion: Myofibroblasts expression is significantly raised in OSMF patients. The expression can also be correlated within different grades of OSMF where advanced stages show comparatively high expression of these smooth muscles like fibroblasts. Hence, we suggest that myofibroblasts could be assessed as markers for analyzing the progression of OSMF.

Down-regulation of miR-29c promotes the progression of oral submucous fibrosis through targeting tropomyosin-1

Various microRNAs (miRs) have been found to be associated with the development of the precancerous condition of the oral cavity, oral submucous fibrosis (OSF). The expression of miR-29c is dysregulated in oral cancer, but its role in OSF has not been investigated. The purpose of the study is to investigate the functional role of miR-29c and its target in OSF. The expression levels of miR-29c in OSF tissues and fibrotic buccal mucosal fibroblasts (fBMFs) were assessed using next-generation sequencing and real-time Polymerase Chain Reaction (PCR) analysis. MiR-29c mimic and inhibitors were employed to examine its functional role of myofibroblast transdifferentiation. In addition, several myofibroblast phenotypes, such as collagen gel contraction and migration were tested, and a luciferase reporter assay was conducted to confirm the relationship between miR-29c and its predicted target, tropomyosin-1 (TPM1). We observed that miR-29c expression was downregulated in fBMFs. fBMFs transfected with miR-29c mimics exhibited reduced migration ability and collagen gel contractility, whereas inhibition of miR-29c in normal BMFs induced the myofibroblast phenotypes. Results from the luciferase reporter assay showed that TPM1 was a direct target of miR-29c and the expression of TPM1 was suppressed in the fBMFs transfected with miR-29c mimics. Besides, we confirmed that the expression of miR-29c was indeed downregulated in OSF specimens. MiR-29c seems to exert an inhibitory effect on myofibroblast activation, such as collagen gel contractility and migration ability, via suppressing TPM1. These results suggested that approaches to upregulate miR-29c may be able to ameliorate the progression of OSF.

Adipose-Derived Stem Cell-Derived Extracellular Vesicles Inhibit the Fibrosis of Fibrotic Buccal Mucosal Fibroblasts via the MicroRNA-375/FOXF1 Axis.

Oral submucous fibrosis (OSF) is a precancerous lesion. Adipose-derived stem cell- (ADSC-) derived extracellular vesicles (EVs) (ADSC-EVs) regulate multiple oral diseases. Hence, this study explored the mechanism of ADSC-EVs in OSF. ADSCs were transduced with microRNA- (miR-) 375 mimic. ADSC-EVs and miR-375-overexpressed ADSC-EVs (EVs-miR-375) were extracted and identified. miR-375 expression in EVs and fibrotic buccal mucosal fibroblasts (fBMFs) was detected. EV uptake by fBMFs was observed. The targeted relationship between miR-375 and forkhead box protein F1 (FOXF1) was predicted and verified. After EVs-miR-375 treatment or FOXF1 overexpression, fBMF cell proliferation, migration, invasion, and apoptosis were evaluated, and levels of apoptosis-related proteins (cleaved-caspase-3, Bax, and Bcl-2) and fibrosis markers (α-SMA, collagen I, and collagen III) were detected. Functional rescue experiments were further performed to verify the role of the miR-375/FOXF1 axis in OSF. miR-375 was notably upregulated in EVs-miR-375 and EVs-miR-375-treated fBMFs (all P < 0.001). ADSC-EVs carried miR-375 into fBMFs. fBMFs can internalize ADSC-EVs. EVs-miR-375 treatment markedly inhibited fBMF cell proliferation, migration, invasion, and fibrosis and promoted apoptosis (all P < 0.01). Moreover, miR-375 targeted FOXF1 in fBMFs. FOXF1 overexpression promoted fBMF cell biological behaviors and fibrosis, which were reversed after EVs-miR-375 treatment (P < 0.01 or P < 0.001). We highlighted that ADSC-EVs inhibited fBMF fibrosis and then suppressed OSF progression via the miR-375/FOXF1 axis.

Silencing periostin inhibits myofibroblast transdifferentiation of fibrotic buccal mucosal fibroblasts

Oral submucous fibrosis (OSF) a well-recognized oral premalignant disorder. Several studies have demonstrated that periostin, a matricellular protein, is involved in the development and pathogenesis of fibrosis diseases. Nevertheless, the contribution of periostin in OSF remains to be uncovered. The purpose of the study was to illustrate the functional role of periostin involved in OSF pathogenesis. RNA-sequencing was employed to screen for differentially expressed genes in normal and OSF tissues. Validation of the upregulation of periostin in OSF specimens and fibrotic buccal mucosal fibroblasts (fBMFs) was conducted by qRT-PCR. The correlation of the gene expression of periostin and various fibrosis markers was analyzed. In addition, the functional role of periostin in myofibroblast features was tested using collagen gel contraction and transwell migration assays. We observed overexpression of periostin in OSF specimens using RNA-sequencing and confirmed its upregulation in OSF tissues and patient-derived fBMFs. Besides, there was a positive relationship between the expression of periostin and several fibrosis-associated markers, including ACTA2 (α-smooth muscle actin; α-SMA), COL1A1 (type 1 collagen α1 chain), TGFB1 (TGF-β1), and FN1 (fibronectin). Furthermore, we examined the effect of silencing periostin on the maintenance of myofibroblast characteristics and showed that knockdown of periostin suppressed the expression of α-SMA. Also, inhibition of periostin markedly downregulated the myofibroblast activities (collagen gel contraction and migration capacities). Our results indicate the aberrant expression of periostin in OSF tissues and myofibroblasts. Moreover, the expression of periostin is positively associated with fibrosis markers, and repression of periostin may be a promising direction to alleviate the progression of OSF.

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.

Malignant transformation of oral submucous fibrosis: A systematic review and meta-analysis.

This systematic review and meta-analysis aimed to determine the proportion of patients who develop oral carcinomas following a diagnosis of oral submucous fibrosis (OSF) in reported longitudinal studies. We also aimed to evaluate the demographic and clinicopathological factors contributing to the progression of OSF to cancer. Individual search strategies were applied for the following bibliographic databases: MEDLINE by PubMed, Scopus, Embase, Web of Science, and Grey literature databases until August 30, 2020. Methodological assessment of the risk of bias of the included studies was undertaken using the modified Newcastle-Ottawa scale. Meta-analyses were conducted using a random-effects (DerSimonian and Liard) method to calculate the pooled proportion of the malignant transformation (MT) in OSF patients. Out of 585 records screened, a total of 9 observational studies were included with a total number of 6,337 patients; of these, 292 OSF cases developed carcinomas. The pooled proportion of the MT was 4.2% (95% CI: 2.7%-5.6%) with an annual transformation rate of 0.73%. Subgroup analysis revealed that the pooled MT proportion was significantly higher among population-based studies in comparison with hospital-based ones (p<.005). Most of the studies showed a high risk of bias. In several studies, there was a lack of information about the demographic and clinicopathological characteristics of OSF patients and associated risk indicators; this insufficiency in details hindered the ability to conduct further subgroup analyses. Despite the poorly reported and the limited number of studies, our analysis confirms that close to 4% of patients diagnosed with OSF may develop oral cancer. Cases with oral epithelial dysplasia had a higher potential for malignant transformation.

Arecoline enhances miR-21 to promote buccal mucosal fibroblasts activation

Oral submucous fibrosis (OSF) is an irreversible fibrosis disease and a potentially malignant disorder in the oral cavity. Various studies have shown that miR-21 was implicated in the fibrogenesis and carcinogenesis, but its functional role in the development of OSF has not been investigated. The expression levels of miR-21 in arecoline-stimulated normal buccal mucosal fibroblasts (BMFs) and OSF specimens were determined by qRT-PCR. Exogenous administration of TGF-β and its inhibitor (SB431542) were utilized to examine the involvement of TGF-β signaling in miR-21 alteration. Collagen gel contraction, transwell migration, and invasion assays were used to assess the myofibroblast activities. The relationship between α-SMA and miR-21 was calculated using the Pearson correlation coefficient. MiR-21 expression was induced in BMFs by arecoline treatment in a dose-dependent manner. Our results showed that this upregulation was mediated by TGF-β signaling. Subsequently, we demonstrated that the administration of the miR-21 inhibitor suppressed the arecoline-induced myofibroblast characteristics, including a higher collagen gel contractility and cell motility, in normal BMFs. Furthermore, inhibition of miR-21 was sufficient to attenuate the myofibroblast features in fibrotic BMFs. Besides, we showed that the expression of miR-21 was aberrantly upregulated in the OSF tissues and there was a positive correlation between miR-21 and myofibroblast marker, α-SMA. MiR-21 overexpression in OSF may be due to the stimulation of areca nut, which was mediated by the TGF-β pathway. Our data suggested that the repression of miR-21 was a promising direction to palliate the development and progression of OSF.

Diminishing reactive adipogenesis leads to disease progression of oral submucous fibrosis

Oral fibroblasts, similar to dermal fibroblasts, have the potential to resist the local insults like trauma to the oral mucosa by differentiating into adipocytes and secreting antimicrobial peptide cathelicidin (Camp) and this physiologic process in known as reactive adipogenesis. We hypothesize that in oral submucous fibrosis (OSF), due to constant secretion and up-streaming of transforming growth factor-beta (TGF- β), oral fibroblast lose their adipogenic differentiation potential and Camp production, which leads to progressive fibrosis in OSF. The implication of this hypothesis could open some promising vistas on still unexplored innate immune systems harboured by oral mucosa. Restoring and maintaining the adipogenic and protective potential of oral fibroblasts by inhibiting TGF- β receptors could hinder the disease progression of OSF.