The role of myofibroblasts in the progression of oral submucous fibrosis: A systematic review

Computational analysis of phytocompounds in Centella asiatica for its antifibrotic and drug-likeness properties - Herb to drug study

Oral submucous fibrosis (OSMF) is a potentially malignant disorder with no permanent cure that affects the quality of life due to trismus. Computational pharmacology has accelerated the discovery of drug candidates for the treatment of incurable diseases. The present study aimed to screen the compounds of the miracle herb Centella asiatica with drug-likeness properties based on the absorption, distribution, metabolism, and excretion (ADME) properties. The pharmacological actions of these screened compounds against OSMF were identified by network pharmacology, gene ontology, pathway enrichment analysis, molecular docking, and simulation. Fifteen drug-like ligands were identified after virtual screening viz; asiatic acid, kaempferol, quercetin, luteolin, apigenin, bayogenin, gallic acid, isothankunic acid, madecassic acid, madasiatic acid, arjunolic acid, terminolic acid, catechin, epicatechin, and nobiletin. 850 potential targets were predicted for the ligands, which were analyzed against 354 proteins associated with OSMF. Compound pathway analysis and disease pathway analysis identified 53 common proteins. The GO enrichment analysis identified 472 biological process terms, 76 molecular function terms, and 44 cellular component terms. Pathway enrichment analysis predicted 142 KEGG pathways, 35 Biocarta pathways, and 236 Reactome pathways for the target proteins. The analysis revealed that the herb targets crucial events of fibrosis such as inflammation, oxidative stress, apoptosis, collagen deposition, and epithelial-mesenchymal transition. The common 53 proteins were used for protein-protein interaction (PPI) network analysis, which revealed 4 key proteins interacting with the phytocompounds viz; transforming growth factor-β1 (TGF-β1), mothers against decapentaplegic-3 (SMAD-3), mitogen-activated protein kinase-1 (MAPK-1) and proto-oncogene tyrosine-protein kinase (SRC). Molecular docking revealed that all ligands had a good binding affinity to the target proteins. Bayogenin had the highest binding affinity towards MAPK-1 (-9.7 kcal/mol), followed by isothankunic acid towards SRC protein (-9.3 kcal/mol). Madasiatic acid had the highest binding affinity to SMAD-3 (-7.6 kcal/mol) and TGF-β1 (-7.1 kcal/mol). Molecular dynamics simulation demonstrated stable ligand protein interactions of bayogenin and MAPK complex, isothankunic acid and SRC complex. This in silico study is the first to identify potential phytochemicals present in Centella asiatica and their target molecules, which might be responsible for reversing OSMF.

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.

Resveratrol inhibits arecoline-induced fibrotic properties of buccal mucosal fibroblasts via miR-200a activation

Background/purpose

Oral submucous fibrosis (OSF) is a precancerous lesion in the oral cavity, commonly results from the Areca nut chewing habit. Arecoline, the main component of Areca nut, is known to stimulate the activation of myofibroblasts, which can lead to abnormal collagen I deposition. Meanwhile, Resveratrol is a non-flavonoid phenolic substance that can be naturally obtained from various berries and foods. Given that resveratrol has significant anti-fibrosis traits in other organs, but little is known about its effect on OSF, this study aimed to investigate the therapeutic impact of resveratrol on OSF and its underlying mechanism.

Materials and methods

The cytotoxicity of resveratrol was tested using normal buccal mucosal fibroblasts (BMFs). Myofibroblast phenotypes such as collagen contractile, enhanced migration, and wound healing capacities in dose-dependently resveratrol-treated fBMFs were examined.

Results

Current results showed that arecoline induced cell migration and contractile activity in BMFs as well as upregulated the expressions of α-SMA, type I collagen, and ZEB1 markers. Resveratrol intervention, on the other hand, was shown to inhibit arecoline-induced myofibroblast activation and reduce myofibroblast hallmarks and EMT markers. Additionally, resveratrol was also demonstrated to restore the downregulated miR-200a in the arecoline-stimulated cells.

Conclusion

In a nutshell, these findings implicate that resveratrol may have an inhibitory influence on arecoline-induced fibrosis via the regulation of miR-200a. Hence, resveratrol may be used as a therapeutic strategy for OSF intervention.

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.

Molecular pathways of oral submucous fibrosis and its progression to malignancy

OBJECTIVE

The review aims to comprehend various factors engaged in the alteration of molecular events resulting in Oral submucous fibrosis (OSMF) and its malignant transformation.

DESIGN

Literature pertinent to pathways involved in OSMF were explored in databases such as PubMed, Scopus and Google Scholar. The relevant literature was reviewed and critically appraised in this narrative review.

RESULTS

Areca nut components influence myriad of cellular molecules such as cytokines, growth factors, myofibroblasts, non-coding RNAs and alter their expression. These aberrantly expressed molecules drive the progression of OSMF from localized inflammation to fibrosis of buccal mucosa. The oral tissue suffers from oxidative stress, hypoxia, autophagy, aberration of cell cycle and DNA damage. Apoptosis of epithelial layer results in its atrophy facilitating deeper penetration of areca nut elements. With the advance of disease, epithelial-mesenchymal transition eventuates and promotes dysplasia. The jeopardized expression of various cellular molecules, suppressed apoptosis, along with increased genetic alterations and neovascularization favors the malignant transformation.

CONCLUSION

OSMF is a progressive disorder with complex mechanism of pathogenesis initiated by inflammation of oral mucosa. Continuous habit of areca nut chewing and the resulting insult to the tissues prevents healing process and is destined to debilitating disease which affects the quality of life with a higher probability of progression to malignancy.

Low LINC02147 expression promotes the malignant progression of oral submucous fibrosis

BACKGROUND

Key lncRNAs associated with the malignant progression of oral submucous fibrosis (OSF) to oral squamous cell carcinoma (OSCC) were identified.

METHODS

Key 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.

RESULTS

Bioinformatics 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.

CONCLUSIONS

Low 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 & 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 <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.

Research Achievements of Oral Submucous Fibrosis: Progress and Prospect

Oral submucous fibrosis (OSMF) is a kind of chronic, insidious disease, and it is categorized into potentially malignant disorders (PMD), which poses a global and regional problem to public health. It is considered to be a multifactorial disease, such as due to areca nut chewing, trace element disorders, and genetic susceptibility. However, there is still no unanimous conclusion on its pathogenesis, diagnosis, and treatment strategies. Hence, this article provides a comprehensive review and prospect of OSMF research, providing scholars and clinicians with a better perspective and new ideas for the research and treatment of OSMF.