miR-200c inhibits the arecoline-associated myofibroblastic transdifferentiation in buccal mucosal fibroblasts

MicroRNA-503 Suppresses Oral Mucosal Fibroblast Differentiation by Regulating RAS/RAF/MEK/ERK Signaling Pathway

The abnormal proliferation and differentiation of oral mucosal fibroblasts (FBs) is the key to the progression of oral submucosal fibrosis. To clarify the mechanism of platelet-derived growth factor (PDGF-BB)-induced FBs fibrosis in oral mucosa, real-time quantitative polymerase chain reaction and Western blot were used in this study to detect the expression of miR-503 and the expression of p-MEK, p-ERK, miR-503, RAF, smooth actin and type I collagen under different time and concentration stimulation of PDGF-BB. The effects of overexpression of miR-503 or RAF on the proliferation and migration of FBs were detected by cell counting kit 8 and cell scratch assay, respectively. A dual luciferase reporter gene assay was used to verify the targeting effect of miR-503 on RAF. The results showed that miR-503 was downregulated in a dose- and time-dependent manner in PDGF-BB-induced FBs. In addition, RAF is a direct target of miR-503 and can be negatively regulated. Overexpression of RAF can promote FB proliferation, migration, differentiation, collagen synthesis, and activation of downstream molecules (MEK/ERK), while overexpression of miR-503 can partially reverse the effects of RAF. Therefore, miR-503 regulates the biological behavior of PDGF-BB-induced oral mucosal FBs by influencing the activation of the RAS/RAF/MEK/ERK signaling pathway.

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.

Exploring Possible Diagnostic Precancerous Biomarkers for Oral Submucous Fibrosis: A Narrative Review

Oral submucous fibrosis (OSF) stands as a progressive oral ailment, designated as a potentially malignant disorder. OSF has gained widespread recognition as a significant precursor to malignant transformation. In the pursuit of dependable, straightforward, and non-invasive diagnostic measures for the early detection of oral malignant progression, research has delved into potential diagnostic biomarkers of OSF. This comprehensive review delves into current investigations that explore the correlation between various biomarkers and OSF. The molecular biomarkers of OSF are categorized based on cytology and sampling methods. Moreover, this review encompasses pertinent studies detailing how these biomarkers are acquired and processed. Within this scope, we scrutinize four potential biomarkers that hold the promise of facilitating the development of diagnostic tools for detecting early-stage OSF.

Salivaomics to decode non-coding RNAs in oral cancer. A narrative review

Oral cancer is the most debilitating disease which affects the orderly life of a human. With so much advancement in research and technology, the average life expectancy of an individual with oral cancer appears to be about 5 years. The changing trend in incidence of oral cancer among young individuals and women without tobacco habits are ascending. Non habit related oral cancer are taking centre stage and multiple factors which induce complex biology are associated in such scenarios. To decipher the aetiology and to understand the process, these cancerous conditions are to be studied at molecular level. Saliva, the most non-invasively obtained body fluid are assessed for biomarkers exclusively in liquid biopsy. This fluid gives a huge platform to study number of molecules associated with oral cancer. Non coding RNAs are transcripts with no protein coding function. They are gaining more importance in recent times. Long noncoding RNA, microRNA are major types of noncoding transcriptome that influences in progression of oral cancer. They seem to play an important role in health and disease. Apart from these, circulating tumour cells, exosomes, extracellular vesicles, antigens and other proteins can be studied from saliva. This review is aimed to update the knowledge on current biomarkers in saliva associated with oral cancer and their epigenetic role in disease progression as well recent advances in detecting these markers to identify the stage of the disease, which will help in deciding the treatment protocol.

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.

MicroRNA-200c-5p Regulates Migration and Differentiation of Myoblasts via Targeting Adamts5 in Skeletal Muscle Regeneration and Myogenesis

Skeletal muscle, as a regenerative organization, plays a vital role in physiological characteristics and homeostasis. However, the regulation mechanism of skeletal muscle regeneration is not entirely clear. miRNAs, as one of the regulatory factors, exert profound effects on regulating skeletal muscle regeneration and myogenesis. This study aimed to discover the regulatory function of important miRNA miR-200c-5p in skeletal muscle regeneration. In our study, miR-200c-5p increased at the early stage and peaked at first day during mouse skeletal muscle regeneration, which was also highly expressed in skeletal muscle of mouse tissue profile. Further, overexpression of miR-200c-5p promoted migration and inhibited differentiation of C2C12 myoblast, whereas inhibition of miR-200c-5p had the opposite effect. Bioinformatic analysis predicted that Adamts5 has potential binding sites for miR-200c-5p at 3'UTR region. Dual-luciferase and RIP assays further proved that Adamts5 is a target gene of miR-200c-5p. The expression patterns of miR-200c-5p and Adamts5 were opposite during the skeletal muscle regeneration. Moreover, miR-200c-5p can rescue the effects of Adamts5 in the C2C12 myoblast. In conclusion, miR-200c-5p might play a considerable function during skeletal muscle regeneration and myogenesis. These findings will provide a promising gene for promoting muscle health and candidate therapeutic target for skeletal muscle repair.

Oral Submucous Fibrosis: Etiological Mechanism, Malignant Transformation, Therapeutic Approaches and Targets

Oral submucosal fibrosis (OSF) is a chronic, progressive and potentially malignant oral disorder with a high regional incidence and malignant rate. With the development of the disease, the normal oral function and social life of patients are seriously affected. This review mainly introduces the various pathogenic factors and mechanisms of OSF, the mechanism of malignant transformation into oral squamous cell carcinoma (OSCC), and the existing treatment methods and new therapeutic targets and drugs. This paper summarizes the key molecules in the pathogenic and malignant mechanism of OSF, the miRNAs and lncRNAs with abnormal changes, and the natural compounds with therapeutic effects, which provides new molecular targets and further research directions for the prevention and treatment of OSF.

The paradigm of miRNA and siRNA influence in Oral-biome

Short nucleotide sequences like miRNA and siRNA have attracted a lot of interest in Oral-biome investigations. miRNA is a small class of non-coding RNA that regulates gene expression to provide effective regulation of post-transcription. On contrary, siRNA is 21-25 nucleotide dsRNA impairing gene function post-transcriptionally through inhibition of mRNA for homologous dependent gene silencing. This review highlights the application of miRNA in oral biome including oral cancer, dental implants, periodontal diseases, gingival fibroblasts, oral submucous fibrosis, radiation-induced oral mucositis, dental Pulp, and oral lichenoid disease. Moreover, we have also discussed the application of siRNA against the aforementioned disease along with the impact of miRNA and siRNA to the various pathways and molecular effectors pertaining to the dental diseases. The influence of upregulation and downregulation of molecular effector post-treatment with miRNA and siRNA and their impact on the clinical setting has been elucidated. Thus, the mentioned details on application of miRNA and siRNA will provide a novel gateway to the scholars to not only mitigate the long-lasting issue in dentistry but also develop new theragnostic approaches.

Noncoding RNAs: Master Regulator of Fibroblast to Myofibroblast Transition in Fibrosis

Myofibroblasts escape apoptosis and proliferate abnormally under pathological conditions, especially fibrosis; they synthesize and secrete a large amount of extracellular matrix (ECM), such as α-SMA and collagen, which leads to the distortion of organ parenchyma structure, an imbalance in collagen deposition and degradation, and the replacement of parenchymal cells by fibrous connective tissues. Fibroblast to myofibroblast transition (FMT) is considered to be the main source of myofibroblasts. Therefore, it is crucial to explore the influencing factors regulating the process of FMT for the prevention, treatment, and diagnosis of FMT-related diseases. In recent years, non-coding RNAs, including microRNA, long non-coding RNAs, and circular RNAs, have attracted extensive attention from scientists due to their powerful regulatory functions, and they have been found to play a vital role in regulating FMT. In this review, we summarized ncRNAs which regulate FMT during fibrosis and found that they mainly regulated signaling pathways, including TGF-β/Smad, MAPK/P38/ERK/JNK, PI3K/AKT, and WNT/β-catenin. Furthermore, the expression of downstream transcription factors can be promoted or inhibited, indicating that ncRNAs have the potential to be a new therapeutic target for FMT-related diseases.

Nanoparticulate strategies for the delivery of miRNA mimics and inhibitors in anticancer therapy and its potential utility in oral submucous fibrosis

MicroRNAs (miRNAs) are naturally occurring noncoding RNAs with multiple functionalities. They are dysregulated in several conditions and can serve as disease biomarkers, therapeutic targets and therapeutic agents. Translation of miRNA therapeutics to the clinic poses several challenges related to the safe and effective delivery of these agents to the site of action. Nanoparticulate carriers hold promise in this area by enhancing targeting efficiency and reducing off-target effects. This paper reviews recent advances in the delivery strategies of miRNAs in anticancer therapy, with a focus on lipid-based, polymeric, inorganic platforms, cell membrane-derived vesicles and bacterial minicells. Additionally, this review explores the potentiality of miRNAs in the treatment of oral submucous fibrosis, a potentially premalignant condition of the oral cavity with no definitive treatment to date.

Long Non-Coding RNAs in Oral Submucous Fibrosis: Their Functional Mechanisms and Recent Research Progress

Many studies have shown that most genomes are transcribed into non-coding RNAs (ncRNAs), including microRNAs (miRs) and long non-coding RNAs (lncRNAs), which can affect different cell characteristics. LncRNAs are long heterologous RNAs that regulate gene expression and various signaling pathways during homeostasis and development. Studies have shown that a lncRNA is an important regulatory molecule that can be targeted to change the physiology and function of cells. Expression or dysfunction of lncRNAs is closely related to various genetic, autoimmune, and metabolic diseases. The importance of ncRNAs in oral submucosal fibrosis (OSF) has garnered much attention in recent years. However, most research has focused on miRs. The role of these molecules in OSF is incompletely understood. This review focuses on the emerging role and function of lncRNAs in OSF as novel regulators. Finally, the potential functional role of lncRNAs as biomarkers for OSF diagnosis is also described. LncRNAs are expected to become a new therapeutic target, but more research is needed to understand their biological functions more deeply.

The functional roles of microRNAs in the pathogenesis of oral submucous fibrosis

Oral potentially malignant disorders (OPMD) are lesions that may precede the onset of cancers in the oral cavity, and oral submucosal fibrosis (OSF) is one of the OPMD that is usually found in the buccal mucosa. Considerable effort has been made to elucidate the pathogenesis of OSF, and emerging evidence has suggested that microRNAs may play significant roles in the development of OSF. Several studies demonstrated that aberrant expression of miRNAs is also observed in the fibrotic BMFs (fBMFs) derived from OSF tissues. For instance, it has been shown that miR-10b, miR-21, and miR-1246 are significantly elevated, and miR-29b, miR-200b, and miR-200c are reduced in fBMFs. This review systematically summarizes the current knowledge regarding the aberrant expression of microRNAs, molecular mechanisms underlying oral fibrogenesis by the dysregulated microRNAs, and how the interaction between microRNAs and long non-coding RNAs contributes to the progression of OSF. An overview of the modes of action by these microRNAs will provide a fundamental basis for clinical application.

Depletion of miR-155 hinders the myofibroblast activities and reactive oxygen species generation in oral submucous fibrosis

BACKGROUND/PURPOSE

Emerging evidence suggests the significance of microRNA-155 (miR-155) in fibrogenesis and oxidative stress accumulation, but its function in oral submucous fibrosis (OSF) has not been investigated. In this study, we assessed the expression of miR-155 and its effects on the maintenance of myofibroblast activation.

METHODS

qRT-PCR was conducted to assess the expression of miR-155 in OSF tissues and fibrotic buccal mucosal fibroblasts (fBMFs) derived from OSF samples. Collagen gel contraction, migration, and invasion capabilities were examined in fBMFs. DCFDA ROS assay was used to examine ROS generation. A luciferase reporter assay was carried out to verify the relationship between miR-155 and its potential target RPTOR.

RESULTS

We showed that the expression of miR-155 was aberrantly upregulated in OSF specimens and fBMFs. Inhibition of miR-155 ameliorated various myofibroblast activities, including collagen gel contraction, migration, and invasion abilities as well as ROS production. Results from the luciferase reporter assay demonstrated that miR-155 directly interacted with its target RPTOR.

CONCLUSION

Taken together, these findings indicate that miR-155 is implicated in the pathogenesis of oxidative stress-associated OSF, possibly through the regulation of RPTOR.

Emerging Role of MicroRNA-200 Family in Dentistry

MicroRNAs (miRNAs) are endogenous non-coding RNAs ~22 nucleotides in length, which have been shown to participate in various biological processes. As one of the most researched miRNAs, the miR-200 family has been found to regulate several factors that are associated with the epithelial to mesenchymal transition (EMT) and cancer stem cells (CSCs) behavior. In this review, we briefly summarize the background of the miR-200 family and their implication in various dental diseases. We focus on the expression changes, biological functions, and clinical significance of the miR-200 family in oral cancer; periodontitis; oral potentially malignant disorder; gingival overgrowth; and other periodontal diseases. Additionally, we discuss the use of the miR-200 family as molecular biomarkers for diagnosis, prognostic, and therapeutic application.

Inhibition of lncRNA HOTTIP ameliorated myofibroblast activities and inflammatory cytokines in oral submucous fibrosis

BACKGROUND/PURPOSE

Long non-coding RNA HOXA transcript at the distal tip (HOTTIP) has been reported to contribute to multiple carcinomas, but whether it involves in the progression of precancerous conditions remains to be determined. Oral submucous fibrosis (OSF) has been known as an oral potentially malignant disorder and attributed to the persistent activation of the myofibroblast.

METHODS

The relative expression of HOTTIP in OSF tissues has been employed by RNA-sequencing and RT-PCR analysis. HOTTIP associated myofibroblasts activities and markers in fibrotic buccal mucosal fibroblast (fBMFs) through loss of function approaches have been evaluated.

RESULTS

In the present study, we found that the expression of HOTTIP was overexpressed in the OSF tissues and positively correlated with several fibrosis markers. To investigate its significance of myofibroblast activation, we first verified the expression level of HOTTIP in the patient-derived fibrotic buccal mucosal fibroblast (fBMFs) was upregulated and conducted the shRNA-mediated knockdown experiment to inhibit its expression followed by numerous examinations. We demonstrated that suppression of HOTTIP downregulated the expression of myofibroblast marker, α-SMA, and type I collagen along with the diminished myofibroblast activities (collagen gel contraction and migration capacities). Furthermore, we showed that silencing HOTTIP lessened the production of various pro-inflammatory cytokines (IL-6 and TNF-α).

CONCLUSION

Collectively, our results suggest that HOTTIP plays a crucial role in the persistent activation of myofibroblasts as well as the chronic inflammation and collagen deposition.

Oral Submucous Fibrosis: A Review on Biomarkers, Pathogenic Mechanisms, and Treatments

Oral submucous fibrosis (OSF) is a collagen deposition disorder that affects a patient’s oral function and quality of life. It may also potentially transform into malignancy. This review summarizes the risk factors, pathogenic mechanisms, and treatments of OSF based on clinical and bio-molecular evidence. Betel nut chewing is a major risk factor that causes OSF in Asia. However, no direct evidence of arecoline-induced carcinogenesis has been found in animal models. Despite identification of numerous biomarkers of OSF lesions and conducting trials with different drug combinations, clinicians still adopt conservative treatments that primarily focus on relieving the symptoms of OSF. Treatments focus on reducing inflammation and improving mouth opening to improve a patient’s quality of life. In conclusion, high-quality clinical studies are needed to aid clinicians in developing and applying molecular biomarkers as well as standard treatment guidelines.

Down-regulation of exosomal miR-200c derived from keratinocytes in vitiligo lesions suppresses melanogenesis

Vitiligo is a refractory disfiguring skin disease. However, the aetiology and pathogenesis of vitiligo have not been fully defined. Previous studies have shown that exosomes from normal human keratinocytes improve melanogenesis by up‐regulating the expression of melanogenesis‐related proteins. Several microRNAs (miRNAs) have been demonstrated to be effective in modulating melanogenesis via exosomes. In the present study, it was found that the effect of exosomes derived from keratinocytes in vitiligo lesions in regulating melanin synthesis is weakened. Furthermore, miR‐200c was detected to be significantly down‐regulated in exosomes from keratinocytes in vitiligo lesions. In addition, miR‐200c enhanced the expression of melanogenesis‐related genes via suppressing SOX1 to activate β‐catenin. In conclusion, our study revealed that the effect of exosomes secreted by keratinocytes in vitiligo lesions exhibited a weaker capacity in promoting melanogenesis of melanocytes. Moreover, the expression of miR‐200c, which mediates melanogenesis in exosomes secreted by keratinocytes in vitiligo lesions, is down‐regulated, which may be one of the pathogenesis in vitiligo. Therefore, keratinocyte‐derived exosomal miR‐200c may be a potential target for the treatment of vitiligo.

miR-10b regulated by Twist maintains myofibroblasts activities in oral submucous fibrosis

BACKGROUND/PURPOSE

Oral submucous fibrosis (OSF) is an oral precancerous disorder associated with the habit of areca nut chewing. MiR-10b has been shown to be upregulated in the oral cancer cells and induced by Twist. Our previous work has revealed that Twist participated in the pathogenesis of OSF and therefore we aimed to investigate whether Twist/miR-10b axis was involved in the activation of myofibroblast in the oral cavity.

METHODS

The expression levels of miR-10b in OSF tissues and fibrotic buccal mucosal fibroblasts (fBMFs) were examined. Besides, the expression of miR-10b was determined in fBMFs following knockdown of Twist or in BMFs after arecoline stimulation. Myofibroblast activities, including collagen gel contraction, migration and wound healing abilities, as well as the expression of α-SMA were measured in fBMFs treated with miR-10b inhibitor. Last, we investigated whether the effect of Twist overexpression could be reversed by suppression of miR-10b.

RESULTS

MiR-10b expression was overexpressed in both OSF tissues and fBMFs. The silence of Twist resulted in the downregulation of miR-10b in fBMFs and arecoline treatment led to an increase of miR-10b in a dose-dependent manner. Inhibition of miR-10b ameliorated the activation of myofibroblasts and the expression of α-SMA. Moreover, we demonstrated that suppression of miR-10b hindered the increased collagen gel contraction caused by Twist overexpression.

CONCLUSION

MiR-10b upregulation in OSF may be due to the stimulation of areca nut, leading to elevated myofibroblast activation. Our findings showed that the areca nut-induced expression of miR-10b was under the regulation of Twist and inhibition of miR-10b may provide a direction for treatment of OSF.

Inhibition of HIF1A-AS1 impedes the arecoline-induced migration activity of human oral mucosal fibroblasts

Long non-coding RNA hypoxia-inducible factor 1α-antisense RNA 1 (HIF1A-AS1) has been known to participate in various types of malignancies, but its role in the development of precancerous oral submucous fibrosis (OSF) has not been investigated. In the current study, we first observed the aberrant upregulation of HIF1A-AS1 in OSF tissues and fibrotic buccal mucosal fibroblasts (fBMFs) isolated from OSF specimens. Next, we demonstrated that administration of arecoline, a natural alkaloid that is found in areca nut, induced the elevation of HIF1A-AS1 in BMFs. This finding showed that the habit of areca nut chewing may lead to an increase of HIF1A-AS1 in oral mucosa. Moreover, we found that knockdown of HIF1A-AS1 hindered the arecoline-stimulated migration capacity in BMFs, suggesting HIF1A-AS1 was critical to the transdifferentiation of BMFs into myofibroblasts. Altogether, our results demonstrated that overexpression of HIF1A-AS1 in OSF tissues may result from the use of areca nut and lead to activation of BMFs, which contribute to the progression of OSF.

Prospective applications of microRNAs in oral cancer

MicroRNAs (miRNAs) are non-coding RNA molecules that are generally encoded by endogenous genes and exert suppressive effects on post-transcriptional regulation of their target genes by translation repression or degradation of mRNA. This subsequently mediates activation or blocking of downstream signaling pathways associated with oral malignancies. Aberrant levels of certain miRNAs have been identified in cell experiments, clinical carcinomatous specimens, saliva, serum or plasma samples of patients with oral malignancies. miRNAs are associated with multiple aspects of oral cancer, including tumor growth, cellular proliferation, apoptosis, migration, invasion, metastasis, glycometabolism, radiosensitivity and chemosensitivity. miRNAs have the potential to be used in clinical applications as minimally invasive or non-invasive tools for early diagnosis and prognosis by the detection of serum, plasma and saliva levels, and may provide a new ancillary or additional reference index of traditional pathological grading and clinical staging. Furthermore, miRNAs may be used as prognostic biomarkers or targets for novel therapies for oral cancer.

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

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

miR-1246 as a therapeutic target in oral submucosa fibrosis pathogenesis

BACKGROUND/PURPOSE

Oral submucous fibrosis (OSF) is a precancerous condition of oral cancer with a complex etiology. Our previous work has demonstrated that non-coding RNA miR-1246 contributes to the cancer stemness of oral cancer. In the current study, we sought to investigate the effect of the inhibition of miR-1246 on the oral fibrogenesis.

METHODS

The expression levels of miR-1246 in OSF tissues and fibrotic buccal mucosal fibroblasts (fBMFs) were examined by qRT-PCR. Collagen gel contraction and migration assays were conducted to evaluate the myofibroblast activities. The relationship between miR-1246 and type I collagen was assessed and the protein expression of type I collagen was determined by Western blot.

RESULTS

MiR-1246 expression was upregulated in both OSF specimen and fBMFs compared to the normal counterparts. Inhibition of miR-1246 successfully suppressed the myofibroblast activities, including collagen gel contractility and migration capacity. Moreover, the expression of miR-1246 was positively correlated with type I collagen and the expression of type I collagen was abrogated by repression of miR-1246.

CONCLUSION

MiR-1246 is not only critical to the maintenance of oral stemness but also important to the activation of myofibroblasts. Our results showed that miR-1246 is positively associated with the type I collagen, which may be a downstream effector of miR-1246 and responsible for the fibrosis effect on fBMFs.

Arctigenin Reduces Myofibroblast Activities in Oral Submucous Fibrosis by LINC00974 Inhibition

Oral submucous fibrosis (OSF) is an oral precancerous condition associated with the habit of areca nut chewing and the TGF-β pathway. Currently, there is no curative treatment to completely heal OSF, and it is imperative to alleviate patients’ symptoms and prevent it from undergoing malignant transformation. Arctigenin, a lignan extracted from Arctium lappa, has been reported to have a variety of pharmacological activities, including anti-fibrosis. In the present study, we examined the effect of arctigenin on the cell proliferation of buccal mucosal fibroblasts (BMFs) and fibrotic BMFs (fBMFs), followed by assessment of myofibroblast activities. We found that arctigenin was able to abolish the arecoline-induced collagen gel contractility, migration, invasion, and wound healing capacities of BMFs and downregulate the myofibroblast characteristics of fBMFs in a dose-dependent manner. Most importantly, the production of TGF-β in fBMFs was reduced after exposure to arctigenin, along with the suppression of p-Smad2, α-smooth muscle actin, and type I collagen A1. In addition, arctigenin was shown to diminish the expression of LINC00974, which has been proven to activate TGF-β/Smad signaling for oral fibrogenesis. Taken together, we demonstrated that arctigenin may act as a suitable adjunct therapy for OSF.