Search

Background/purpose: Oral submucous fibrosis (OSF), characterized by excessive collagen deposition by myofibroblasts, is often linked to Areca nuts consumption. Probiotics consumption has shown protective effects against fibrotic diseases, and recently, their metabolic byproducts, known as postbiotics, have demonstrated superior advantages over probiotics. However, studies on the therapeutic impact of postbiotics on OSF have been scarce. Therefore, this study aims to examine the effect of PostBio GK4, a postbiotic derived from Lactobacillus pentosus GK4, on OSF and explore its underlying mechanisms. Materials and methods: The cytotoxicity of GK4 in normal buccal mucosal fibroblasts (BMFs) and fibrotic BMFs (fBMFs) were assessed. Following this, we evaluated the effects of GK4 on collagen contraction, migratory, and wound healing capacities in arecoline-induced fibrotic BMFs. Next, Western blotting and ELISA were employed to assess GK4's impact on fibrosis-related proteins such as COL1A1, and α-SMA, as well as on TGF-β and Smad2/3 signaling pathway. Results: Arecoline was shown to stimulate cell migratory, contractile and wound healing abilities as well as the expression of α-SMA and COL1A1 in BMFs. Treatment with GK4 reduced all arecoline-induced phenomena in BMFs. Moreover, GK4 diminished the increased expression of TGF-β and Smad2/3. Conclusion: Our findings proposed that GK4 may exert a suppressive effect on arecoline-induced myofibroblast activities via the inhibition of TGF-β and Smad2/3 signaling pathway. Therefore, GK4 holds promise as an adjunct therapeutic approach for intervening in OSF. Further in-vivo and clinical studies are warranted to validate these observations.

Background/purpose: Oral submucous fibrosis (OSF) is a condition characterized by inflammation and excessive collagen deposition, which has been identified as a potentially malignant disorder. Recently, several microRNAs (miRNAs) have been shown to be implicated in various disorders associated with fibrosis. However, how these miRNAs modulate OSF development is poorly understood. Therefore, the study aimed to identify the specific miRNAs that contribute to the progression of OSF and to investigate their molecular mechanisms in promoting fibrosis. Materials and methods: The expression and clinical significance of potential pro-fibrosis miRNA in the OSF cohort and primary buccal mucosal fibroblasts were confirmed through RNA sequencing and qRT–PCR. Luciferase reporter activity assay, miRNA mimic or inhibitor, and short-hairpin RNA silencing were used to elucidate the molecular mechanism of miRNA. Transwell migration, collagen contraction, and reactive oxygen species (ROS) generation detection were used to investigate the effects of this mechanism on the myofibroblast phenotype and cellular pro-fibrosis capacity. Results: This study demonstrated that miR-190a was overexpressed in fibrotic buccal mucosal fibroblasts (fBMFs). Transfecting fBMFs with miR-190a inhibitor resulted in reduced cell migration, collagen gel contraction, ROS generation, and expression of fibrotic markers. Furthermore, miR-190a exerted this pro-fibrosis property by direct binding to its target, Krüppel-like factor 15 (KLF15). The results also indicated that the aberrant upregulation of miR-190a, in turn, downregulated the expression of KLF15, which resulted in the activation of myofibroblast. Conclusion: Our findings demonstrated that miR-190a was involved in myofibroblast activation, suggesting that targeting the miR-190a/KLF15 axis may be a feasible approach in the therapy of OSF.

Background/purpose: Persistent activation of myofibroblasts is attributed to various dysregulated biological events conferring multiple types of fibrosis diseases, including oral submucous fibrosis (OSF). Although the significance of non-coding RNAs (ncRNAs) in the occurrence of fibrosis has been appreciated, the detailed mechanisms still have not been fully elucidated. The aim of this study was to identify key dysregulated ncRNAs and elucidate their pro-fibrotic mechanisms in promoting myofibroblast activation and the pathological development of OSF. Materials and methods: Expression of non-coding RNAs and mRNAs in OSF cohort was determined using RNA sequencing and qRT-PCR. The molecular axis of pro-fibrotic ncRNAs were exploited via luciferase reporter activity assay and RNA expression rescue experiments. Functional assays, including collagen gel contraction, wound healing ability, cell migration, and reactive oxygen species (ROS) production, were conducted to assess the changes in the myofibroblastic phenotypes of primary human buccal mucosal fibroblasts. Results: Herein, we found that long non-coding RNA MetaLnc9 was upregulated in OSF specimens and positively associated with several fibrosis markers. Silencing of MetaLnc9 diminished the features of activated myofibroblasts and the production of ROS. We not only showed that MetaLnc9 functioned as a competitive endogenous RNA of microRNA (miR)-143, but also demonstrated that the pro-fibrosis effect of MetaLnc9 on myofibroblast activities was mediated by suppression of miR-143. Moreover, our data showed that fascin actin-bundling protein 1 (FSCN1) was a direct target of miR-143 and positively related to MetaLnc9. Conclusion: Upregulation of MetaLnc9 may enhance the activation of myofibroblasts by sponging miR-143 and titrating its inhibitory property on FSCN1.

Background/purpose: Accumulating evidence has suggested that treatment failure of cancer therapy can be attributed to cancer stem cells (CSCs). Among numerous regulators of cancer stemness, non-coding RNAs (ncRNAs) have gained significant attention recently. In this study, we examined the role of gastric adenocarcinoma predictive long intergenic noncoding RNA (GAPLINC) in oral CSCs (OCSCs). Materials and methods: RNA Sequencing and quantitative real-time polymerase chain reaction (qRT-PCR) were used to determine the expression of GAPLINC. Flow cytometry and sphere-forming assay were exploited to isolate OCSCs. Measurement of aldehyde dehydrogenase 1 (ALDH1) activity, CD44 expressing cells, and various phenotypic assays, such as self-renewal, migration, invasion, and colony-forming abilities, were conducted in CSCs of two types of oral cancer cells (SAS and GNM) following the knockdown of GAPLINC. A luciferase reporter was also carried out to validate the direct interaction between GAPLINC and microRNA (miR)-331-3p. Results: Our results showed that GAPLINC was overexpressed in OCSCs from patient-derived and oral cancer cell lines. We demonstrated that silencing of GAPLINC in OCSCs downregulated various CSC hallmarks, such as ALDH1 activity, percentage of CD44-expressing cells, self-renewal capacity, and colony-forming ability. Moreover, our results revealed that the effect of GAPLINC on cancer stemness was mediated by direct repression of miR-331-3p. Conclusion: These data have potential clinical implications in that we unraveled the aberrant upregulation of GAPLINC and demonstrated that suppression of GAPLINC may reduce cancer stemness via sequestering miR-331-3p.

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.

Background/purpose: Periodontitis is an inflammatory condition of the tooth-supporting structures triggered by the host's immune response towards the bacterial deposits around the teeth. It is well acknowledged that pro-inflammatory interleukin (IL)-6, IL-8, MCP-1 as well as the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, are the key modulators in the activation of this response. Erbium-doped yttrium-aluminium-garnet (Er:YAG) laser, a solid-state crystal laser have been commonly used in the treatment of periodontal diseases. However, little is understood about the molecular mechanism of the Er:YAG laser, especially in targeting the host immune response brought on by periodontal pathogens. Hence, the current study focused on the protective effects of Er:YAG laser on periodontitis in-vitro in terms of pro-inflammatory cytokines, chemokines and NLRP3 inflammasome expressions. Materials and methods: Human periodontal ligament fibroblast (PDLFs) were first stimulated with lipopolysaccharides (LPS) from P. gingivalis (Pg-LPS) to simulate periodontitis. Cells were then irradiated with Er:YAG laser of ascending energy densities (3.6–6.3 J/cm2), followed by cell proliferation and wound healing assay. Next, the effects of Er:YAG laser on the expressions of IL-6, IL-8, MCP-1, NLRP3, and cleaved GSDMD were examined. Results: Pg-LPS was found to reduce cell's proliferation rate and wound healing ability in PDLFs and these were rescued by Er:YAG laser irradiation. In addition, LPS stimuli resulted in a marked upregulation in the secretion of IL-6, IL-8 and MCP-1 as well as the mRNA and protein expression of NLRP3 and cleaved-GSDMD protein whereas Er:YAG laser suppressed the elicited phenomena. Conclusion: To our knowledge, this is the first study to look into the laser's implication on the NLRP3 inflammasome in periodontitis models. Our study reveals a crucial role of Er:YAG laser in ameliorating periodontitis in-vitro through the modulation of IL-6, IL-8, MCP-1 and the NLRP3 inflammasome and highlights that the control of the NLRP3 inflammasome may become a potential approach for periodontitis.

Periodontitis, characterized by inflammation and loss of periodontal tissue, is a significant health complication for individuals with diabetes mellitus (DM). Buildup of advanced glycation end-products (AGEs) in DM poses an increased risk of periodontitis via inflammaging. Ganoderma immunomodulatory protein (GMI) shows promise in suppressing inflammaging by mitigating oxidative stress and inflammation via Nrf2 modulation. However, its specific protective effects are not fully understood. Thus, this study aimed to investigate GMI’s anti-inflammaging properties and its underlying mechanism in diabetic-associated periodontitis (DP). We first simulated DP by culturing human gingival fibroblasts (HGFs) with AGEs and lipopolysaccharides from P. gingivalis (LPS). We then evaluated the impact of GMI on cell proliferation, migration and wound healing. Additionally, we assessed GMI’s effects on the components of inflammaging such as reactive oxygen species (ROS) formation, cellular senescence expression, IL-6 and IL-8 secretions, and NF-κB phosphorylation. Next, we explored whether GMI’s anti-inflammaging effects are mediated through the Nrf2 pathway by evaluating Nrf2 and HO-1, followed by the assessment of IL-6 and IL-8 post-Nrf2 knockdown. Our findings revealed that GMI treatment suppressed ROS production, cell senescence, IL-6 and IL-8 and NF-κB phosphorylation. Furthermore, GMI upregulated Nrf2/HO-1 expression and its protective effects were reversed when Nrf2 was knocked down. In conclusion, GMI exerts its anti-inflammaging effect via the modulation of the Nrf2/NF-κB signaling axis in DP in vitro, highlighting its potential as an effective adjunct treatment for diabetes-related periodontitis.

Background/purpose: Increasing evidence regarded the existence of cancer stem cells (CSCs) as a leading cause of therapy failure and tumor relapse due to their self-renewal and differentiation abilities. Although ectopic overexpression of micro-RNAs (miRNAs) can modulate the cancer stemness and tumor development in oral cancer, their molecular mechanism is still unclear. Therefore, in the present study, we attempt to uncover the role of miR-146a in the maintenance of oral CSCs. Materials and methods: The expression of miR-146a was determined using qRT-PCR analysis. Aldehyde dehydrogenase (ALDH) enzymic activity and sphere formation assays were used to evaluate the cancer stemness and self-renewal, respectively. Functional assays, including migration/invasion Transwell and colony formation assay, were used to evaluate the aggressive abilities. Luciferase reporter assay was performed to validate the relationship between miR-146a and Numb. Results: In the present study, we reported an increased expression of miR-146a in the oral squamous cell carcinoma (OSCC) specimen, primary OSCC cells sphere, and high ALDH1 activity population within OSCC cells. Inhibition of miR-146a significantly suppressed the ALDH1 activity, self-renewal capacity, and aggressive abilities, including migration, invasion, and colony formation. Moreover, we demonstrated that Numb is a functional target of miR-146a in OSCC-CSCs. Notably, silencing of Numb could retrieve the self-renewal and migration impaired by knockdown of miR-146a. Conclusion: Our results indicate that miR-146a can regulate the cancer stemness in OSCC by modulating Numb, and hence miR-146a/Numb axis can serve as a potential target for oral cancer therapy.

Background/purpose: Diabetes mellitus (DM) is a chronic metabolic disorder that affects millions of people worldwide. A growing evidence suggests that hyperglycemia in DM causes a pre-aging and pro-inflammatory condition known as inflammaging, which increases periodontitis susceptibility. Bromelain has been demonstrated to have anti-inflammatory and anti-aging properties in variety of tissues, but its effects on diabetic periodontitis remain unclear. Thus, the aim of this study is to investigate the its Bromelain's impact in diabetic periodontitis in terms of inflammation and senescence activity. Materials and methods: We assessed the wound healing capacity, production of pro-inflammatory cytokines Interleukin (IL)-6 and IL-8 and senescence marker p16 in human gingival fibroblasts (HGFs) in response to Advanced glycation end-products (AGEs) stimulant, with or without Bromelain treatment. The expression of p65, p-ERK, and p-p38 were also examined to elucidate whether Bromelain's anti-inflammaging activity is mediated through NF-κB and MAPK/ERK signaling pathway. Results: Bromelain concentrations ranging from 2.5 to 20 g/mL had no adverse effect on HGF cell proliferation. Bromelain improved wound healing in HGFs with AGEs stimulation. In addition, Bromelain suppressed the production of pro-inflammatory cytokines IL-6 and IL-8 in HGFs elicited by AGEs. Meanwhile, Bromelain treatment also inhibited the senescence activity and expression of p16 in AGEs-stimulated HGFs. Western blot analysis indicated that the upregulation of p-ERK, p-p38 and p65 induced by AGEs were inhibited by Bromelain in HGFs. Conclusion: These data suggest that excessive AGEs in the gingiva may lead to the accumulation of pro-inflammatory cytokines and marked senescence activity. Bromelain application may be helpful in enhancing wound healing by suppressing inflammaging via downregulation of NF-κB and MAPK/ERK signaling pathways in DM individuals with periodontal disease.

Background/purpose: Oral submucous fibrosis (OSF) is a premalignant disorder that is associated with betel nut chewing. The purpose of the study was to establish the role of histone deacetylase (HDAC) 8, one of histone deacetylases, in the regulation of fibrotic conditions to provide a therapeutic potential for OSF. Materials and methods: First, we examined the expression of HDAC8 in fibrotic buccal mucosal fibroblasts (fBMFs) and OSF tissues. Markers of myofibroblasts and TGF-β signaling were conducted in fBMFs with HDAC8 knockdown were examined. Furthermore, epithelial–mesenchymal transition (EMT) markers, collagen gel contraction and migration ability were also examined in fBMFs transfected with sh-HDAC8. HDAC8 inhibitor was used to analyze the collagen gel contraction and wound healing ability in fBMFs. Results: We observed the mRNA expression of HDAC8 was significantly increased in fBMFs. Compared to normal tissues, the protein level of HDAC8 was upregulated in OSF. Next, mRNA and protein expression of HDAC8 was significantly decreased, accompanying downregulation of α-SMA and COL1A1 in fBMFs infected with sh-HDAC8. To determine the critical role of HDAC8 in OSF fibrogenesis, results revealed that TGF-β secretion and the expression of EMT transcription factor SNAIL and p-Smad were significantly decreased in HDAC8-knockdown fBMFs. We further demonstrated that collagen gel contraction and migration ability were significantly decreased in fBMFs transfected with sh-HDAC8. Last, results revealed that significantly reduced collagen gel contraction and wound healing ability in fBMFs with HDAC8 inhibitor treatment. Conclusion: We concluded that downregulation of HDAC8 alleviated the activities of myofibroblasts and TGF-β/Smad signaling pathway in OSF.

Background/purpose: :Both periodontal disease and diabetes mellitus (DM) are long-term inflammatory disorders that are highly prevalent and have a significant health impact. Inflammaging, a state of pre-aging and hyperinflammatory state has been acknowledged for its role in DM patients to have heightened risk of periodontitis. Numerous evidences revealed that inflammaging contributed by cell senescence, acceleration of inflammation and oxidative stress participates in the destruction of periodontium in DM. Abilities of vitamin D in suppressing inflammation and oxidative stress have been revealed in a range of tissues, however in DM’s gingival cells, the effect remain undefined. Materials and methods: : Under the stimulation of advanced glycation end-products (AGEs), we assessed the cell proliferation in human gingival fibroblast (HGF), IL-6 and IL-8 secretions, cellular senescence expression and generation of reactive oxygen species (ROS) with or without vitamin D intervention. Following that, we examined the expression of Nrf2 and HO-1 to see if vitamin D was able to modulate the anti-oxidant signaling. A knockdown experiment was then conducted to proof the participation of Nrf2 on the secretion of pro-inflammatory IL-6 and IL-8. Results: : Following the treatment of vitamin D, AGEs-elicited IL-6 and IL-8 production and cell senescence were dose-dependently repressed. Moreover, vitamin D attenuated AGEs-induced ROS in a dose-dependent pattern. Results from qRT-PCR demonstrated vitamin D reversed the suppression of Nrf2 and HO-1 induced by AGEs. Our findings revealed that the anti-inflammatory and anti-oxidant effect in vitamin D was mediated via the upregulation of Nrf2 expression. Conclusion: : These data showed that high levels of AGEs in the gingiva lead to inflammaging reflected by increased pro-inflammatory cytokines, cell senescence expression and oxidative stress. Vitamin D supplementation can reduce oxidative stress and inflammation via the upregulation of Nrf2 signaling and hence, may be a potential approach for treatment of diabetes-associated periodontitis.

Biomedical information retrieval for diagnosis, treatment and prognosis has been studied for a long time. In particular, image recognition using deep learning has been shown to be very effective for cancers and diseases. In these fields, scaphoid fracture recognition is a hot topic because the appearance of scaphoid fractures is not easy to detect. Although there have been a number of recent studies on this topic, no studies focused their attention on surgical treatment recommendations and nonsurgical prognosis status classification. Indeed, a successful treatment recommendation will assist the doctor in selecting an effective treatment, and the prognosis status classification will help a radiologist recognize the image more efficiently. For these purposes, in this paper, we propose potential solutions through a comprehensive empirical study assessing the effectiveness of recent deep learning techniques on surgical treatment recommendation and nonsurgical prognosis status classification. In the proposed system, the scaphoid is firstly segmented from an unknown X-ray image. Next, for surgical treatment recommendation, the fractures are further filtered and recognized. According to the recognition result, the surgical treatment recommendation is generated. Finally, even without sufficient fracture information, the doctor can still make an effective decision to opt for surgery or not. Moreover, for nonsurgical patients, the current prognosis status of avascular necrosis, non-union and union can be classified. The related experimental results made using a real dataset reveal that the surgical treatment recommendation reached 80% and 86% in accuracy and AUC (Area Under the Curve), respectively, while the nonsurgical prognosis status classification reached 91% and 96%, respectively. Further, the methods using transfer learning and data augmentation can bring out obvious improvements, which, on average, reached 21.9%, 28.9% and 5.6%, 7.8% for surgical treatment recommendations and nonsurgical prognosis image classification, respectively. Based on the experimental results, the recommended methods in this paper are DenseNet169 and ResNet50 for surgical treatment recommendation and nonsurgical prognosis status classification, respectively. We believe that this paper can provide an important reference for future research on surgical treatment recommendation and nonsurgical prognosis classification for scaphoid fractures.

Background/Purpose: NF-κB family of transcription factors are the major contributors to malignant tumor progression, maintenance of cancer stemness, and enhancement of chemoresistance. Fenofibrate, a lipid-lowering drug, has been considered as a candidate for repurposing in the treatment of cancer through various pathways involved in apoptosis, cell cycle, migration, and invasion, including NF-κB. Nevertheless, whether fenofibrate possesses the potential to inhibit cancer stemness remained to be examined. Methods: Cytotoxicity of fenofibrate was estimated by MTT assay. The cells expressing stemness marker were detected by flow cytometry using ALDEFLUOR™ Kit. The secondary sphere formation assay was used to assess the self-renewal ability. Transwell system was used to evaluate migration and invasion capacities. NF-κB expression was measured by the immunoblotting system. Results: In the present study, we demonstrated that fenofibrate inhibited cell viability, expression of stemness marker, self-renewal, migration, and invasion capacities in a dose-dependent manner. Of note, fenofibrate targeted cancer stem cells of oral squamous cell carcinoma (OSCC-CSCs) and had minimal effects on normal cells. Moreover, administration of fenofibrate at a lower concentration was sufficient to diminish the expression of NF-κB p50 and p65. Conclusion: This study demonstrated that the inhibitory effects of fenofibrate on OSCC-CSCs properties may be associated with downregulation of NF-κB. These results indicated that administration of fenofibrate may serve as an alternative strategy for OSCC therapy.

Right ventricular outflow tract ventricular tachycardia (RVOT VT) is a well-recognised subtype of idiopathic ventricular tachyarrhythmia and often described in young healthy individuals. This arrhythmia typically occurs in patients with a structurally normal heart, and in this context is generally considered benign. In this case we present a rare association between RVOT VT and a ruptured sinus of Valsalva aneurysm in a patient known to have a restrictive ventricular septal defect. Prompt surgical intervention was necessary to prevent potentially life threatening consequences.The diagnostic and surgical evaluation learnt from this case would be useful to remind clinicians to explore rarer causes of RVOT VT especially when patients have underlying congenital heart disease. This case also highlights the importance of utilizing multi-modality imaging for the anatomical assessment of this pathology, which aids definitive management.

Background/Purpose: 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. Methods: 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). Results: 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. Conclusion: 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.

Periodontitis is a progressive inflammation condition and a primary cause of tooth loss in adults. As one of the abundant cell types in the periodontium, periodontal ligament fibroblasts (PDLFs) play an integral role in the maintenance and regeneration of periodontal tissue. Our previous work has shown that the application of Er:YAG laser increased the cell proliferation and migratory capacity of PDLFs via induction of galectin-7. In the present study, we aimed to evaluate if the forced expression of galectin-7 directly affected the cellular phenotypes of PDLFs. Our results showed that the cell proliferation, transwell migration, invasion, and wound healing capacities were all upregulated in PDLFs with the ectopic expression of galectin-7. These results suggest that therapeutic approaches to enhance the expression of galectin-7 in periodontium may accelerate tissue regeneration by recruiting more PDLFs to the injured site.

Background/purpose: Betel nut chewing is the major risk factor of oral submucous fibrosis (OSF). Various studies have sought to discover alternative strategies to alleviate oral fibrogenesis. In the present study, we aimed to evaluate the anti-fibrosis effect of paeonol, a phenolic component derived from Paeonia Suffruticosa. Methods: The cytotoxicity of paeonol was tested using normal and fibrotic buccal mucosal fibroblasts (fBMFs) derived from OSF tissues. Collagen gel contraction, Transwell migration, invasion, and wound healing capacities were examined. Besides, the activation of TGF-β/Smad2 signaling and expression levels of type I collagen, α-SMA, and long non-coding RNA HOTAIR were measured as well. Results: Paeonol exerted a higher cytotoxic effect on fBMFs compared to normal BMFs. The arecoline-induced myofibroblast activities, including collagen gel contractility, cell motility, and wound healing ability were all suppressed by paeonol treatment. In addition, the activation of the TGF-β/Smad2 pathway was inhibited along with a lower expression of α-SMA and type I collagen in paeonol-treated cells. Also, the administration of paeonol decreased the mRNA expression of HOTAIR in fBMFs. Conclusion: Our results indicate that paeonol may be a promising compound to attenuate the progression of oral fibrogenesis in OSF patients.

Background/purpose: Oral cancer is one of the common cancers worldwide. Emerging evidence has indicated that microRNAs (non-coding RNA molecules of approximately 22 nucleotides in length) are implicated in the regulation of cancer stemness. However, the functional role of microRNA-509 (miR-509) in the characteristics of oral cancer stem cells (CSCs) has not been unraveled. Materials and methods: The expression level of miR-509 in ALDH1+ and sphere oral CSCs was examined by qRT-PCR. The aldehyde dehydrogenase 1 (ALDH1) activity and CD44 expression were assessed using flow cytometry. Self-renewal, transwell migration, and colony formation assays were conducted to measure the CSC phenotypes. Besides, a luciferase reporter assay was used to confirm the direct interaction between miR-509 and its target polo-like kinase 1 (plk1). Results: We showed the expression of miR-509 was downregulated in the CSCs derived from oral cancer cells (SAS), and upregulation of miR-509 diminished the several CSCs features, including ALDH1 activity, self-renewal capacity, CD44 expression, migration, and colony-forming abilities. Moreover, the result from the luciferase reporter assay validated the direct binding of miR-509 to plk1. Conclusion: Our results suggest that the miR-509/plk1 axis may mediate the cancer stemness in oral cancer, and targeting this axis may attenuate the progression of oral cancer.

Background/purpose: Oral submucous fibrosis (OSF) has been regarded as a premalignant disorder of oral cancer, and myofibroblasts are the main cells that are responsible for pathological fibrosis. Hence, elucidation of the molecular mechanism underlying myofibroblast activation is important to treat OSF. MicroRNA-21 (miR-21) is a well-known fibrosis non-coding RNA, and its role in the development of OSF remains largely unclear. Materials and methods: Luciferase reporter assay was used to confirm the direct interaction between miR-21 and its target programmed cell death 4 (PDCD4). The expression level of PDCD4 in OSF was examined by qRT-PCR. Myofibroblast activities were assessed by collagen gel contraction and transwell migration assays. Results: Our result validated the direct binding of miR-21 to PDCD4. We showed the expression of PDCD4 was downregulated in OSF specimens and negatively correlated with miR-21. Our results suggested that overexpression of PDCD4 in fibrotic buccal mucosal fibroblasts (fBMFs) mitigated the myofibroblast activities, including collagen gel contractility and migration capacity. Moreover, we showed miR-21 contributed to myofibroblast activation of BMFs through repression of PDCD4. Conclusion: Our results suggest that the miR-21/PDCD4 axis mediates the myofibroblast activation of BMFs, and targeting this axis may exert an anti-fibrosis effect.

Background/purpose: Oral cancer has been recognized as one of the most common malignancies worldwide and ranks the fifth leading cause of cancer death in Taiwan. A variety of studies have demonstrated that microRNAs are involved in the regulation of the hallmarks of oral carcinogenesis. Nevertheless, the effect of miR-1266-5p on the tumorigenesis of oral cancer has not been investigated, and not to mention, its functional role in oral cancer. Materials and methods: The upregulation of miR-1266-5p in SASVO3 and SASM5 cells was identified by RNA-Seq and examined by qRT-PCR analysis. The phenotypic assays including proliferation activity, migration capacity, invasion, wound healing, and colony-forming abilities were conducted in oral cancer cells after knockdown of miR-1266-5p. Luciferase reporter and western blotting were used to validate DAB2IP was a direct target of miR-1266-5p in oral cancer. Results: We identified that miR-1266-5p was significantly overexpressed in highly tumorigenic SASVO3 cells and metastatic SASM5 cells. qRT-PCR revealed that miR-1266 significantly increased upregulated in oral cancer and lymph node metastatic tissues compared to normal counterparts We found that downregulation of miR-1266-5p inhibited the proliferation and clonogenicity capacities of SASVO3 cells. Knockdown of miR-1266-5p also inhibited migration/invasion and self-renewal abilities in SASM5 cells. Moreover, we validated miR-1266-5p directly bound to the 3′UTR of DAB2IP in oral cancer cells. We found that DAB2IP knockdown reversed the inhibitory effects of self-renewal and migration mediated by silencing of miR-1266-5p. Conclusion: miR-1266 functions as a biomarker in oral cancer patients, and downregulation of miR-1266 may ameliorate the oncogenic and metastasis potential of oral cancer by targeting DAB2IP.

Over the past few decades, recognition of early lung cancers was researched for effective treatments. In early lung cancers, the invasiveness is an important factor for expected survival rates. Hence, how to effectively identify the invasiveness by computed tomography (CT) images became a hot topic in the field of biomedical science. Although a number of previous works were shown to be effective on this topic, there remain some problems unsettled still. First, it needs a large amount of marked data for a better prediction, but the manual cost is high. Second, the accuracy is always limited in imbalance data. To alleviate these problems, in this paper, we propose an effective CT invasiveness recognizer by semi-automated segmentation. In terms of semi-automated segmentation, it is easy for doctors to mark the nodules. Just based on one clicked pixel, a nodule object in a CT image can be marked by fusing two proposed segmentation methods, including thresholding-based morphology and deep learning-based mask region-based convolutional neural network (Mask-RCNN). For thresholding-based morphology, an initial segmentation is derived by adaptive pixel connections. Then, a mathematical morphology is performed to achieve a better segmentation. For deep learning-based mask-RCNN, the anchor is fixed by the clicked pixel to reduce the computational complexity. To incorporate advantages of both, the segmentation is switched between these two sub-methods. After segmenting the nodules, a boosting ensemble classification model with feature selection is executed to identify the invasiveness by equalized down-sampling. The extensive experimental results on a real dataset reveal that the proposed segmentation method performs better than the traditional segmentation ones, which can reach an average dice improvement of 392.3%. Additionally, the proposed ensemble classification model infers better performances than the compared method, which can reach an area under curve (AUC) improvement of 5.3% and a specificity improvement of 14.3%. Moreover, in comparison with the models with imbalance data, the improvements of AUC and specificity can reach 10.4% and 33.3%, respectively.

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.

Background/purpose: Cancer stem cells (CSCs) have been known to be implicated in tumorigenesis, metastasis, and drug resistance in oral squamous cell carcinomas (OSCC). In this study, we aimed to investigate whether magnolol, a polyphenolic component derived from Magnolia officinalis, exhibited the anti-CSCs properties. Methods: The cytotoxicity of magnolol was tested using normal gingival epithelioid SG cells and sphere-forming OSCC-CSCs isolated from SAS, OECM1, and GNM cells. Secondary sphere-forming ability, the proportion of ALDH1 positive cells, Transwell migration, and invasion capacities were examined as well. The chemosensitive effects of magnolol were investigated using MTT, secondary sphere-forming, and invasion assays. Results: Magnolol exerted a higher cytotoxicity of OSCC-CSCs and cancer stemness features, including self-renewal ability, the expression CSC marker, migration, and invasion capacities were all downregulated in magnolol-treated OSCC-CSCs. Moreover, administration of magnolol potentiated the effect of cisplatin, including a decrease in cell viability, self-renewal, and invasion activities. In addition, we observed that the secretion of IL-6 and phosphorylation of Stat3 were decreased in OSCC-CSCs treated with magnolol. Conclusion: Our data suggest that magnolol is able to target CSCs and suppress the cancer stemness properties, at least in part, via IL-6/Stat3 signaling. Besides, a dietary supplement of magnolol may function as an adjunct to cisplatin treatment.

Background/purpose: The habit of areca nut chewing has been regarded as an etiological factor of precancerous oral submucous fibrosis (OSF). In the present study, we aimed to evaluate the anti-fibrosis effect of honokiol, a polyphenolic component derived from Magnolia officinalis. Methods: The cytotoxicity of honokiol was tested using normal and fibrotic buccal mucosal fibroblasts (fBMFs) derived from OSF tissues. Collagen gel contraction, Transwell migration, invasion, and wound healing capacities were examined. Besides, the expression of TGF-β/Smad2 signaling as well as α–SMA and type I collagen were measured as well. Results: Honokiol exerted higher cytotoxicity of fBMFs compared to normal cells. The arecoline-induced myofibroblast activities, including collagen gel contractility, cell motility and wound healing capacities were all suppressed by honokiol treatment. In addition, the expression of the TGF-β/Smad2 pathway was downregulated along with a lower expression of α–SMA and type I collagen in honokiol-receiving cells. Conclusion: Our data suggest that honokiol may be a promising compound to alleviate the progression of oral fibrogenesis and prevent the transformation of OSF oral epithelium into cancer.

Background/Purpose: 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. Methods: 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. Results: 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). Conclusion: 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.

Background/Purpose: Periodontal disease and diabetes mellitus (DM) are both chronic inflammatory and highly prevalent diseases. A large amount of evidence suggested that the accumulation of oxidative stress plays a significant role in the deterioration of both diseases. Magnolol has been known to possess anti-inflammatory and anti-oxidant activities in various tissues, but its effects on gingival cells under diabetic conditions have not been fully understood. Methods: We assessed the generation of reactive oxygen species (ROS), Transwell migration, and wound healing ability in response to the advanced glycation end products (AGEs) stimulation with or without Magnolol treatment. Subsequently, we examined the expression of Nrf2 and HO-1 to ascertain whether Magnolol was able to activate the anti-oxidant signaling. We also measured the secretion of IL-6 and IL-8, and conducted a knockdown experiment to elucidate the effect of Mrf2 on their secretion. Results: The AGEs-induced ROS was dose-dependently downregulated following the Magnolol treatment. Likewise, the reduced Transwell migration and wound healing ability were improved by various concentrations of Magnolol. Results from qRT-PCR indicated that the suppression of Nrf2 and HO-1 following AGEs stimulation was reversed by Magnolol. Also, the AGEs-elicited production of IL-6 and IL-8 was inhibited by Magnolol. Moreover, our results demonstrated that this anti-inflammatory effect was mediated by the upregulation of Nrf2. Conclusion: These findings showed that excessive AGEs in the gingiva may lead to the accumulation of ROS and pro-inflammatory cytokines. Supplement of Magnolol may be beneficial to improve the impaired wound healing and inflammation by upregulation of Nrf2 signaling for DM patients with periodontal disease.

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.

Background/Purpose: Oral cancer stem cells (CSCs) have been considered as the key cells that are implicated in tumor recurrence and metastasis. In recent years, great attention has been paid to the significance of various non-coding RNAs due to their regulatory roles in oral CSCs. Although the function of long non-coding RNA MEG3 in various cancers has been investigated, its effects on the features of oral CSCs remained to be determined. Methods: The expression levels of MEG3 in tongue squamous cell carcinomas and prognostic effect have been evaluated. We assessed the expression of MEG3 in sphere cells (oral CSCs) using qRT-PCR. Secondary sphere formation and invasion assays were conducted to evaluate the self-renewal and metastatic abilities, respectively. Bioinformatics software and luciferase reporter assay were used to predict and verify the relationship between MEG3 and miR-421. Results: MEG3 was downregulated in the tissues of oral cancer and associated with a poor prognosis. In oral CSCs, the expression of MEG3 was repressed and overexpression of MEG3 resulted in suppression of self-renewal and invasion abilities. Luciferase reporter assay showed that miR-421 directly interacted with MEG3, and our subsequent experiment demonstrated that elevation of miR-421 reversed the MEG3-inhibited characteristics of oral CSCs. Conclusion: Our findings suggest that MEG3 can serve as a tumor suppressor in oral CSCs by impeding the action of miR-421. Moreover, targeting MEG3-miR-421 axis has the potential to mitigate the tumor recurrence and metastasis.

Background/purpose: 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. Methods: 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. Results: 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. Conclusion: 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.

Background/purpose: Among various dental lasers, the erbium-doped yttrium-aluminum-garnet (Er:YAG) laser has great potential for periodontal treatment including soft and hard tissue ablation with minimal thermal side effects under suitable energy densities and it has multiple effects on tissues for wound-healing benefits. In the present study, we sought to reveal the molecular mechanism underlying the impact of Er:YAG laser on PDL fibroblasts. Methods: Cells were irradiated by a Er:YAG laser with various energy densities (3.6–6.3 J/cm2). MTT assay was used for cell proliferation, and the transwell system was employed for migration and invasion abilities. The wound healing capacity was evaluated by a scratch assay. After confirming these effects, qRT-PCR and western blotting analysis was applied to identify the differentially galectin-7 expression in the irradiated cells. Knockdown experiments were conducted to reveal the functional role of galectin-7 in the modulation of Er:YAG laser-mediated effects. Results: 4.2 J/cm2 was the lowest energy density to induce the optimal cell proliferation, migration and invasion abilities. In the group of upregulated genes, galectin-7 was selected for further examination and its elevation after Er:YAG laser treatment was validated by RT-PCR and Western blot. We demonstrated that silence of galectin-7 abrogated the effects of Er:YAG laser on cell proliferation, migration ad invasion, suggesting the Er:YAG laser promoted these effects through induction of galectin-7. Conclusion: These findings indicated that Er:YAG laser may accelerate the regeneration process in periodontal tissues through enhancement of their proliferative and mobile activities. Additionally, the significance of galectin-7 in the Er:YAG laser-elicited benefits was demonstrated.

Background/Purpose: Oral cancer is amongst the most prevalent cancers worldwide with rising incidence. Various attempts have been made to elucidate its pathogenesis, and we sought to examine the function of a ubiquitin E3 ligase that was encoded by STUB1. Methods: The mRNA expression of STUB1 in oral cancer samples and normal counterparts was determined by qRT-PCR. Numerous assays to assess the features of cancer cells, including self-renewal capacity, invasion and migration abilities were conducted following knockdown or overexpression of STUB1. Results: The expression level of STUB1 was reduced in oral cancer, which was associated with a reduced relapse-free survival. Two oral cancer cell lines with low expression of STUB1 (SAS and HSC3) were chosen for the overexpression of STUB1. We showed that ectopic expression of STUB1 led to the downregulation of TGM2, a multifunctional protein that contributed to cancer progression in several cancers. Our results demonstrated that overexpression of STUB1 suppressed the cancer aggressiveness, while restoration of TGM2 reverted the effects. Last, we showed that STUB1 silencing resulted in enhanced cancer features. Conclusion: The abnormal downregulation of STUB1 may lessen its suppressive effect on TGM2, which induced the onset or exacerbated the progression of oral cancer. The therapeutic approach to enhance the expression of STUB1 could be a promising direction for cancer therapy.

Background/Purpose: Gingival overgrowth can occur as a result of poor oral hygiene or a side effect of taking certain medications, such as cyclosporine A (CsA). It has been shown that this immunosuppressant drug induces epithelial-to-mesenchymal transition (EMT) in the gingival epithelium but the associated molecular mechanism remains to be elucidated. Methods: We first assessed the relative expression of microRNA-200a (miR-200a) in response to the CsA treatment using qRT-PCR. Next, luciferase reporter assay was applied to examine whether miR-200a was able to regulate ZEB2 and Western blot was utilized to measure the expression of ZEB2 in normal human gingival fibroblasts (HGFs). To confirm the significance of miR-200a and ZEB2 in the CsA-induced gingival overgrowth, miR-200a inhibitor and shRNA mediated knockdown of ZEB2 were used and cell proliferation in HGFs was assessed by MTT assay. Results: The expression of miR-200a was dose-dependently downregulated following the CsA treatment. Luciferase reporter assay confirmed that ZEB2 was a direct downstream target regulated by miR-200a and ZEB2 was indeed increased after the administration of CsA. We demonstrated that knockdown of ZEB2 hampered the CsA-induced HGFs proliferation and the elevated cell proliferation due to inhibition of miR-200a was reversed by repression of ZEB2. Conclusion: Our results showed that insufficient miR-200a in HGFs caused by CsA administration may lead to gingival enlargement mediated by the upregulation of ZEB2. This finding supported that CsA-induced EMT contributed to the adverse effect of using CsA and miR-200a may serve as an upstream target to prevent the overgrowth of the gingiva.

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.

Background/purpose: Oral submucous fibrosis (OSF) represents a precancerous lesion of oral mucosa that may progress into oral cancer and its major etiological factor is areca nut chewing. Carboxyl-terminus of Hsp70-interacting protein (CHIP) functions as an ubiquitin E3 ligase and is associated with fibrosis diseases. In the current study, we sought to investigate whether CHIP participated in the areca nut-mediated OSF development. Methods: The mRNA expression of CHIP in arecoline-stimulated buccal mucosal fibroblasts (BMFs) and OSF tissues was determined by qRT-PCR. Collagen gel contraction, migration and invasion assays were carried out to evaluate the myofibroblast activation. The protein expression levels of α-SMA and transglutaminase 2 (TGM2) were assessed by Western blot. Results: The expression level of CHIP was reduced in BMFs following arecoline treatment in a dose-dependent manner, which was consistent with the observation of lower CHIP expression in OSF specimen compared to the normal counterparts. Ectopic expression of CHIP mitigated the myofibroblast activities, including elevated collagen gel contractility and cell motility. In addition, we showed that overexpression of CHIP downregulated the α-SMA and TGM-2 expression, which may lead to less fibrosis alteration. Conclusion: CHIP may not only function as a key regulator of protein quality control but also a critical deciding factor to oral fibrogenesis. Our findings suggested that CHIP possesses the anti-fibrotic effect, which may be mediated by TGM2 regulation. Restoration of CHIP could be a therapeutic direction to help OSF patients. Keywords: Oral submucous fibrosis, CHIP, Myofibroblasts

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. Keywords: Oral submucous fibrosis, MicroRNA-1246, Type I collagen, Buccal mucosal fibroblasts

Oral submucous fibrosis (OSF) is a chronic fibrotic remodeling disease that can progress to oral cancer. However, efficient clinical diagnosis and treatment methods for OSF are still lacking. This study investigated the anti-fibrotic effect of fucoidan on oral fibrosis. To evaluate the fibrotic ability (myofibroblast activities), we performed wound-healing, Transwell migration, and collagen contraction assays by using patient-derived normal and fibrotic buccal submucous fibroblasts (BMFs and fBMFs, respectively). RNA-sequencing and dual-luciferase reporter and RNA immunoprecipitation chip assays were performed to identify the clinical significance and molecular mechanism of non-coding RNAs. Fucoidan suppressed the myofibroblast activities and inhibited the MEG3 in fBMFs. MEG3 was overexpressed in the OSF tissue and was positively associated with myofibroblast markers. Knockdown of MEG3 markedly inhibited myofibroblast activities, which were restored by inhibiting miR-181a and overexpressing Egr1. The results from luciferase reporter and RIP assays confirmed that MEG3 functioned as a competing endogenous RNA (ceRNA) and could directly target miR-181a, thereby preventing the miR-181a-mediated translational repression of Egr1. This study demonstrated that MEG3 exerts a profibrotic effect on OSF by targeting miR-181a/Egr1. Therefore, the administration of fucoidan may serve as a potential therapeutic strategy for OSF by targeting the overexpression of MEG3.