OBJECTIVES:Masticatory function may influence the gut microbial metabolism via mechanical and neurohumoral mechanisms. However, the relationship between microbial metabolites and systemic indicators in healthy adults remains unclear. METHODS:This cross-sectional study included 20 healthy young adults (mean age: 27.6 ± 2.5 years). Masticatory performance was assessed using a validated chewing examination with gummy jelly as the test food. Fecal short-chain fatty acids were quantified by gas chromatography. Microbial metabolic functions were inferred using PICRUSt2 based on 16S rRNA gene sequences. Defecation frequency and body mass index were assessed using questionnaires and anthropometry, respectively. Correlation, regression, and mediation analyses were performed using 2,000 bootstrap samples. RESULTS:Masticatory performance showed nominal positive associations with several microbial metabolic pathways (p < 0.05), but none remained significant after false discovery rate correction (q ≥ 0.05). Propionate concentration and masticatory performance showed trends toward associations with defecation frequency, although these associations did not reach statistical significance. The mediation pathway involving propionate and defecation frequency was suggested but not significant. CONCLUSION:Overall, masticatory performance was associated with fecal propionate levels in healthy young adults. Associations among defecation frequency, BMI, and predicted microbial metabolic pathways are exploratory and require confirmation in larger studies.
OBJECTIVES:Hypophosphatasia (HPP) is a congenital disease caused by mutations in the tissue non-specific alkaline phosphatase gene. HPP is characterized by impaired hard tissue mineralization and premature tooth loss. Mild-type HPP includes childhood-, adult, and odonto-HPP. Mild-type HPP is difficult to diagnose because individuals with mild-type HPP do not have characteristic symptoms. The effects of applying mechanical stress, such as that caused by orthodontic force, on the teeth and jawbones of patients with mild-type HPP are unknown; therefore, in this study these effects were examined in mild-type HPP model mice. METHODS:A 10 gf nickel-titanium closed-coil spring was placed on the maxillary incisors and left first molar (M1) of mild-type HPP model mice (Akp2+/-). The M1 moved mesially to the maxillary incisors 14 days before sampling. RESULTS:Tooth movement distance, serum alkaline phosphatase (ALP) and serum C-terminal telopeptide of Type I collagen (CTX-1) levels did not differ between Akp2+/- and normal (Akp2+/+) mice. However, alveolar bone resorption on the compressed side was higher in Akp2+/- mice than that in normal mice. The cancellous bone quality on the compressed was side was lower in Akp2+/- than in Akp2+/+ mice. Fibrous structures infiltrated the bone resorption sites, and the number of osteoclasts was markedly higher in Akp2+/- mice. CONCLUSIONS:The application of orthodontic force to mice with mild-type HPP did not affect the serum ALP and bone resorption marker CTX-1 levels, or tooth movement. However, compression induced alveolar bone resorption due to an increase in osteoclasts. These findings support the importance of differentially diagnosing mild-type HPP before initiating treatment.
BACKGROUND:Leptin receptor (LepR)+ stromal cells are widely recognized as skeletal stem/progenitor cells (SSPCs) in the bone marrow that generate osteolineage cells, and contribute to skeletal homeostasis under steady-state conditions and tissue repair. By expressing representative niche factors, including stem cell factor and C-X-C motif chemokine ligand 12, LepR+ SSPCs function as key microenvironmental components of the hematopoietic stem cell (HSC) niche. Over the past decade, genetic cell-labeling studies have identified LepR+ SSPCs in craniofacial tissues, including in the periodontal ligament and alveolar bone marrow, where they differentiate into osteoblasts and cementoblasts. HIGHLIGHT:Emerging evidence indicates that periodontal LepR + cells contribute to orthodontic remodeling, periodontal repair, and extraction socket healing. Independent SSPC populations may coexist with LepR+ SSPCs in oral tissues and contribute in parallel to tissue homeostasis. Periodontal LepR+ cells also express HSC niche-associated factors, suggesting their possible role in the regulation of local immune and hematopoietic environments. Because oral tissues are continuously exposed to mechanical forces and the oral microbiome, LepR+ SSPCs in the oral environment may function through unique regulatory mechanisms that influence skeletal homeostasis and hematopoiesis. CONCLUSION:In this review, current knowledge regarding LepR+ SSPCs in periodontal tissues is summarized, and their emerging roles in skeletal maintenance, tissue repair, and hematopoietic regulation is discussed. Further elucidation of the regulatory mechanisms governing these cells will advance understanding of oral skeletal and hematopoietic biology, and may provide new insights into oral health and regenerative strategies.
Objectives Sodium chloride (NaCl), an important mineral for human homeostasis, is perceived by taste receptors. The objective of this study was to investigate how perceived intensity and preference for NaCl by taste receptors were affected after mixing with thickeners in electrophysiological and behavioral experiments in Wistar/ST rats. Methods Chorda tympani nerve responses to 0.1 M NaCl, 0.1 M sucrose, 3 mM hydrochloride, and 1 mM quinine hydrochloride, with and without thickeners, were measured by electrophysiology. Commercially available grades of 3% xanthan gum-based (X), 2% guar gum-based (G), and 4.7% starch-based (S) thickeners were used. To investigate the effect of thickener concentration, responses to 0.1 M NaCl mixed with 1%, 2%, and 3% X were measured. A two-bottle preference test and a brief-access test were performed using the following stimuli: 0.1 M NaCl, distilled water, and their mixture with one of the three thickeners. Results The degree of suppression varied depending on taste stimuli and thickeners; however, in most instances, chorda tympani nerve responses to the tested taste stimuli were suppressed by mixing with thickeners. The response and preference for 0.1 M NaCl were suppressed by mixing with X and G. The brief-access test demonstrated that the suppression was caused by the taste effect. Conclusion Mixing thickeners, such as X and G, but not S, with NaCl, suppressed perceived intensity and preference for NaCl.
Objectives Circadian rhythms in peripheral organs undergo dynamic reorganization during postnatal development. However, the mechanisms underlying the maturation of circadian clocks in the salivary glands, particularly in relation to feeding behavior, remain poorly understood. In this study, we aimed to characterize the developmental maturation of circadian rhythms in the mouse submandibular gland (SMG). Methods PERIOD2::LUCIFERASE bioluminescence rhythms were recorded from cultured suprachiasmatic nucleus (SCN) and SMG tissues isolated from mice at postnatal days 0, 1, 7, 14, 21, and 28, and 8 weeks. Maternal behavior and pup feeding activity were continuously monitored using infrared video recording. Peak phases and circadian periods were analyzed to evaluate developmental changes. Results Robust circadian oscillations were observed in the SCN tissue at all developmental stages, with stable periods and peak phases. In contrast, rhythms in the SMG were rapidly damped in culture, and exhibited a progressive phase shift from the light phase to the middle of the dark phase during postnatal development. Circadian periods in both tissues remained close to 24 h throughout development. Behavioral analyses revealed that developmental changes in maternal care and feeding activity were closely associated with the phase realignment of SMG rhythms. After weaning, SMG peak phases resembled those in adult mice. Conclusions Postnatal maturation of circadian rhythms in the SMG is characterized by progressive phase realignment that parallels the transition from suckling to independent feeding. These findings suggest that developmental coordination between feeding behavior and peripheral clock machinery contributes to the establishment of circadian regulation of salivary function.
BACKGROUND:Porphyromonas gingivalis is a periodontal pathogen that primarily mediates its interactions with host tissues and other bacteria through fimbrial structures. The diversity and assembly mechanisms of its fimbriae are fundamental to understanding its pathogenicity, and its roles in periodontal and systemic diseases. This bacterium mainly expresses two types of fimbriae, FimA and Mfa1. Recent structural and genetic studies have demonstrated that these fimbriae conform to the conserved assembly principles of Type V fimbriae shared by Bacteroidia-class bacteria. HIGHLIGHTS:This review focuses on Mfa1 fimbriae, and it summarizes the current knowledge on their assembly mechanisms, genetic diversity, components, and strain-dependent structural variations. In particular, the balance between conserved structural features and strain-specific variations is discussed, focusing on the molecular basis of fimbrial formation and incorporation of accessory proteins. The discussion centers on the major fimbrillin Mfa1 anchor protein, Mfa2, accessory proteins, Mfa3 and Mfa4, and the variable Type IX secretion system-dependent accessory protein, Mfa5. CONCLUSION:By integrating recent findings, this review emphasizes how a conserved Type V assembly framework, combined with variations in accessory components, enables Mfa1 fimbriae to maintain structural stability, while accommodating strain-dependent diversity. This synthesis provides an updated perspective on the balance between stability and strain-dependent structural adaptability in Mfa1 fimbrial systems, and their potential implications for fimbrial assembly, bacterial adhesion, and host-microbe interactions.
Objectives Oral squamous cell carcinoma (OSCC) is characterized by aggressive biological behavior and limited therapeutic responsiveness. In this study, the objectives were to investigate the effects of cinobufagin (CBG) on the progression of OSCC, and to elucidate the underlying molecular mechanisms. Methods The effects of CBG on OSCC cells were evaluated using in vitro assays to assess cell proliferation, clonogenic growth, apoptosis, migration, and invasion. Nuclear factor-kappa B (NF-κB) signaling activity was determined by immunoblotting, luciferase reporter assay, and p65 subcellular localization. The antitumor activity of CBG was further assessed in a xenograft mouse model, and its potential toxicity was evaluated by histological examination of the major organs. Results CBG treatment suppressed proliferation and clonogenic capacity of OSCC cells, while promoting apoptotic cell death. In addition, CBG significantly reduced the migratory and invasive abilities of OSCC cells. Mechanistically, CBG attenuated NF-κB signaling by decreasing p65 phosphorylation and inhibiting its nuclear translocation, resulting in reduced NF-κB transcriptional activity. Pharmacological activation of NF-κB partially reversed the antitumor effects of CBG. Moreover, CBG markedly inhibited in vivo tumor growth, and no histological toxicity was observed. Conclusions CBG suppressed the malignant progression of OSCC, in vitro and in vivo. Its antitumor effects are associated with inhibition of p65 nuclear translocation and attenuation of NF-κB signaling, suggesting that CBG may represent a potential therapeutic candidate for OSCC.
Background Oral squamous cell carcinoma (OSCC) arises from the mucosal epithelium and is the most common cancer of the oral cavity. There are few major oncogenic events that could be therapeutically targeted in OSCC; therefore, the identification of novel target factors based on the molecular mechanisms of the tumorigenesis of OSCC is required. Highlight The extracellular matrix (ECM), a component of the tumor microenvironment, surrounds tumor cells, and it provides a scaffold for tumors. The ECM promotes tumor progression, and mechanical cues from increased ECM stiffness are involved in tumorigenesis. Recently, mechanosensitive ion channels have been identified as receptors for the ECM. Mechanosensitive ion channels respond to mechanical cues, alter intracellular signaling and affect tumor cell behavior such as cell proliferation. This review explores the role of the ECM and its receptors, mechanosensitive ion channels, and particularly Ca2+ channels. Conclusion Mechanosensitive Ca2+ channels, Piezo-type mechanosensitive ion channel component 1 and transient receptor potential vanilloid 4, promote tumorigenesis of OSCC. We demonstrated that Ca2+ channels may represent novel molecular targets in OSCC.
Objectives Temporomandibular joint osteoarthritis (TMJ-OA) involves cartilage degeneration and bone changes; however, the mechanisms of onset and progression are unclear. Recently, it has been shown that asporin, an extracellular matrix protein, increases as knee osteoarthritis progresses and suppresses the TGF-β pathway. However, the asporin levels in later stages of TMJ-OA, when cartilage destruction occurs, are not known. In this study, we examined the relationship between asporin and the pathological progression of TMJ-OA. Methods We constructed TMJ-OA models in 12-week-old male C57BL/6J mice by partial discectomy and evaluated these at 3 days and 2, 4, 8, 12, and 16 weeks postoperatively. Cartilage degeneration was evaluated using a modified Mankin scoring system after safranin O staining. The mRNA and protein expression of asporin, Tgfb1, and Smad2/3 were compared between experimental and sham-operated control mice using reverse-transcription polymerase chain reaction and immunohistochemical staining, respectively. Results Safranin O staining intensity increased at 8 weeks postoperatively, and partial cartilage loss was observed at 16 weeks postoperatively. The modified Mankin score was higher in the experimental group than in the control group, and peaked at 16 weeks postoperatively. Asporin mRNA and protein expression was higher in the experimental group at all time points. Smad2/3 mRNA expression was higher, whereas p-SMAD2/3 levels were lower in the experimental group.TGF-β levels were higher in the experimental group. Conclusion Asporin mRNA and protein levels are high in the early and late stages of TMJ-OA. Asporin may be a potential biomarker of TMJ-OA and a potential therapeutic target.
BACKGROUND:Dental implant osseointegration remains a significant clinical challenge in patients with compromised bone health, particularly in those affected by osteoporosis. Parathyroid hormone (PTH; teriparatide, PTH 1-34) is an established osteoanabolic agent with recognized impacts on bone remodelling. Its use has been proposed as an adjunctive strategy to enhance peri-implant bone regeneration under osteoporotic conditions. This updated systematic review provides evidence from preclinical evaluations of the effects of PTH supplementation on dental implant osseointegration in osteoporotic animal models. We conducted an indexed database search for studies published between January 2015 and August 2025. Outcomes were assessed using histomorphometry, microcomputed tomography, and biomechanical parameters. Methodological quality was assessed using SYRCLE's risk-of-bias tool. HIGHLIGHTS:• Intermittent PTH administration consistently enhanced peri-implant outcomes in osteoporotic animal models. • Combination regimens outperform PTH monotherapy in osteoporotic models. • Methodological heterogeneity limits clinical translation of preclinical findings. CONCLUSION:Preclinical evidence supports PTH supplementation as a promising adjunct to enhance peri-implant bone quality and mechanical stability in osteoporotic settings. To date, substantial heterogeneity in experimental design, outcome assessment, and study quality limits meta-analysis and translational interpretation. Standardized outcome measures and robust human trials are required before clinical applications can be considered.
Background Formalin-fixed paraffin-embedded (FFPE) samples are widely used for pathological diagnosis because they enable histological evaluation, special staining, and immunohistochemistry. The advent of next-generation sequencing (NGS) technologies has expanded their applications to comprehensive molecular analyses including genomic mutation profiling and spatial transcriptomics. FFPE samples present challenges hampering full realization of their extensive utility including nucleic acid degradation and interlaboratory variability, which necessitate standardized workflows to ensure reproducible and reliable molecular analysis results. Although FFPE-based molecular analytical methods are maturing, a unified workflow for multilayered and comprehensive pathological investigations, from FFPE sample preparation to NGS-based molecular analyses, has not been established. Highlight NGS-based genomic mutation profiling identifies key gene mutations underlying disease-driving mechanisms, using FFPE-derived DNA for large-scale gene panel analyses. This approach facilitates tailored therapeutic selection and offers considerable diagnostic and prognostic insights. Spatial transcriptomics complements these genomic analyses by providing spatially resolved gene expression data, coupling molecular findings with tissue architecture. FFPE samples expand access to spatial transcriptomics, informing hypothesis generation and detailed analyses of cellular dynamics. Conclusions This review emphasizes the integration of NGS-based genomic mutation profiling and spatial transcriptomics using FFPE samples. Combining these complementary methodologies facilitates elucidation of multilayered disease mechanisms, driving innovations in diagnostic accuracy, personalized treatment strategies, and unraveling intricate biological processes. Overcoming current challenges, including nucleic acid degradation and workflow inconsistencies, will allow researchers and clinicians to achieve comprehensive pathological insights with unprecedented precision.
Objectives Gingival epithelial cells (GECs), the first line of defense in the oral mucosa, are constantly exposed to microbial and inflammatory stimuli. Tumor necrosis factor-alpha (TNF-α) is a major cytokine involved in periodontal inflammation; however, the mechanisms by which GECs respond to sustained TNF-α exposure remain unclear. This study investigated the cellular and transcriptional responses of human GECs to sustained TNF-α stimulation and explored the associated mechanisms. Methods Human gingival epithelial Ca9-22 cells were stimulated with TNF-α (2 ng/mL) every 24 h for 4 days. Interleukin-8 (IL-8) secretion was measured using an enzyme-linked immunosorbent assay. Global transcriptomic changes were analyzed by RNA sequencing, followed by differential gene expression and functional enrichment analyses using the DESeq2 and g:Profiler software. Results A single TNF-α stimulation significantly increased IL-8 production, whereas repeated stimulations progressively attenuated IL-8 secretion, indicating an adaptive (tolerance-like) response. RNA sequencing identified 2674 differentially expressed genes among the control, TNF-α∗1, and TNF-α∗4 groups. Early stimulation (TNF-α∗1) predominantly upregulated genes associated with immune and antiviral responses, whereas sustained stimulation (TNF-α∗4) induced gene expression patterns related to DNA replication and epithelial structural organization. Conclusions These findings indicate that under sustained TNF-α stimulation, human GECs initially induce gene expression related to inflammatory responses but subsequently exhibit transcriptional adaptation, which may contribute to regulating mucosal homeostasis during chronic inflammation.
Objectives: Multiple genes are responsible for the absence of teeth at birth, known as congenital tooth agenesis. The humanized anti-USAG-1 antibody, TRG035, was developed for use in molecular-targeted therapy for the regeneration of congenitally absent teeth in patients with congenital tooth agenesis. Detecting congenital tooth agenesis in children aged 2-5 years using X-ray examination alone is challenging. Therefore, developing imaging biomarkers that identify early tooth buds and ridges during the bud and early cap stages is essential. In this study, the aim was to develop imaging biomarkers by combining MRI and CT/X-rays to identify each developmental stage from the dental lamina to the tooth germ. Methods: Ferret pups aged 0-25 days were photographed and micro-CT was performed. Results: An imaging biomarker using MRI and CT/X-rays were developed that could visualize the dental lamina and pre-calcified tooth germ, both of which were previously difficult to accurately identify. Conclusions: This system is expected to enable the accurate diagnosis of congenital tooth agenesis and contribute to the clinical development of treatments for this condition.
Immunoglobulin A (IgA)-producing cells in the three major murine salivary glands (SGs) were analyzed using flow cytometry. Sublingual glands (SLGs) had significantly higher frequencies of IgA+ cells than other SGs. IgA+ cells expressed CC chemokine receptor 10 (CCR10). The messenger RNA expression level of CC chemokine ligand 28 (CCL28), a CCR10 ligand, was also significantly higher in SLGs. The IgA level in SLGs was highest among major SGs. However, surgical resection of SLGs did not affect the IgA level in the saliva. These data clearly show that the distribution of IgA-producing cells is significantly different between major SGs.
Imidapril, an angiotensin-converting enzyme inhibitor, enhances the swallowing reflex and reduces the incidence of aspiration pneumonia. The aim was to identify the primary afferent fibers involved in imidapril-mediated enhancement of the swallowing reflex in an arterially perfused rat model. Enhancement of swallowing burst amplitude was abolished following bilateral glossopharyngeal nerve transection, whereas enhancement persisted after bilateral superior laryngeal nerve transection. These findings suggest that the glossopharyngeal nerve is essential for imidapril-enhanced swallowing. The results provide insights into the neural mechanisms underlying modulation of the swallowing reflex by pharmacological agents.
Objectives Sodium hypochlorite (NaClO) is widely used as a root canal irrigant because it is an effective antimicrobial agent; however, cytotoxicity to periapical tissues remains a clinical concern. Peracetic acid (PAA) is a well-established disinfectant, but its oral biocompatibility, particularly at low concentrations, and commercially formulated preparations have not been fully evaluated. Methods The antimicrobial efficacy and biocompatibility of a low-concentration PAA-based commercial disinfectant (Actril) were tested against representative oral pathogenic bacteria. Minimum inhibitory, bactericidal, and biofilm inhibitory concentrations were determined, and cytotoxicity toward gingival epithelial cells and periodontal ligament fibroblasts was assessed. Bactericidal activity against Enterococcus faecalis biofilms were evaluated using live/dead staining. Irrigation efficacy was further examined in E. faecalis-infected extracted human teeth using scanning electron microscopy and quantitative polymerase chain reaction. Results Actril exhibited antimicrobial activity at PAA-equivalent concentrations markedly lower than those required for NaClO, with reduced cytotoxicity toward periodontal tissue-related cells. Live/dead staining demonstrated bactericidal effects within E. faecalis biofilms, although variability was observed at threshold concentrations. In extracted tooth models, Actril facilitated biofilm disruption and exposure of dentinal tubules within a clinically relevant irrigation time. Quantitative analyses confirmed significant reduction of bacteria compared with non-irrigated controls, comparable to the effects of NaClO. Conclusions Although PAA itself is not a novel antimicrobial agent, a low-concentration, commercially formulated PAA-based disinfectant demonstrated a favorable balance between antimicrobial efficacy and biocompatibility in oral biofilm models. These findings support the potential application of PAA as a low-toxicity antimicrobial strategy in endodontic environments.
BACKGROUND:Dental plaque is a highly organized polymicrobial biofilm, in which extracellular DNA serves as a vital structural and functional component of the extracellular matrix. The human antimicrobial peptide LL-37 plays an important role in oral innate defense, exhibiting both antimicrobial and immunomodulatory activities. Our recent study indicated that LL-37 forms stable complexes with bacterial DNA in dental plaque. This review summarizes current knowledge of the molecular mechanisms and immunological consequences of LL-37-bacterial DNA interactions in dental plaque, highlighting their potential implications in biofilm structure, innate immunity, and periodontal pathogenesis. HIGHLIGHT:LL-37 binds to oral bacterial DNA forming stable, nuclease-resistant, high-molecular-weight complexes with an aggregated morphology. These complexes abrogate the intrinsic antimicrobial activity of LL-37 while enhancing the stability and cohesiveness of the biofilm matrix. Moreover, LL-37-bacterial DNA complexes act as immunostimulatory molecules by activating TLR9 and the NLRP3 inflammasome, thereby triggering proinflammatory cytokine production in host immune cells. Notably, this immunostimulatory capacity varies with the bacterial source of the DNA, suggesting species-specific modulation of host responses. CONCLUSION:LL-37-bacterial DNA complex formation represents a key event at the interface of innate defense and dysbiosis in dental plaque. This dual nature of LL-37, whereby it acts as an antimicrobial peptide when alone, yet promotes biofilm formation and inflammation when complexed with bacterial DNA, sheds new light on the mechanisms underlying biofilm persistence and chronic inflammation. Understanding this interaction may open new avenues for therapeutic strategies targeting biofilm-associated periodontal diseases.
OBJECTIVES:Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the viral agent responsible for the COVID-19 pandemic and primarily invades the body through the oral cavity. Cetylpyridinium chloride (CPC), a widely used component of oral care products, has demonstrated antiviral effects against SARS-CoV-2; however, the clinical evidence remains limited. This study investigated the virucidal effects of oral CPC in patients with COVID-19 and its impact on reverse transcription polymerase chain reaction (RT-PCR) positivity. METHODS:Thirty-four patients with COVID-19 were initially recruited after obtaining positive PCR test result. This study was conducted during a nationwide Delta-variant-driven epidemic characterized by high viral loads and enhanced transmissibility. Saliva was collected at seven predefined time points to assess the effects of CPC-containing tablets and mouthwash. Viral RNA levels and infectious viral titers were quantified using qRT-PCR and plaque assays. Sixteen patients with detectable SARS-CoV-2 RNA in baseline saliva samples who completed all scheduled samplings constituted the final analytical cohort. RESULTS:During the Delta-variant-predominant period, CPC-containing tablets reduced both SARS-CoV-2 RNA levels and viral infectivity in saliva. In contrast, CPC-containing mouthwashes did not significantly reduce viral RNA levels compared to baseline samples. The RT-PCR positivity rates after CPC use varied according to the applied cycle threshold (Ct) cutoff values. CONCLUSIONS:CPC-containing tablets transiently decrease the SARS-CoV-2 salivary viral load and infectivity and may help reduce the risk of transmission in public settings. When CPC formulations are used prior to saliva-based PCR testing, the Ct cut-off values may require adjustment. CLINICAL SIGNIFICANCE:Despite challenges in conducting saliva-based clinical research in COVID-19 patients, this study provides clinical evidence supporting the antiviral efficacy of CPC formulations on salivary SARS-CoV-2 during the Delta-variant pandemic.
Background Head and neck squamous cell carcinoma (HNSCC) arises from the squamous epithelium of the head and neck region, comprising heterogeneous lesions with distinct risk factors and diverse genetic and epigenetic alteration patterns. HNSCC is often difficult to control when lymph node metastasis has occurred, and treatment outcomes remain unsatisfactory. Elucidating the genetic and epigenetic profiles of cancer-associated genes is essential for improving clinical outcomes, yet to date the key molecules driving HNSCC progression remain unclear. Highlight We identified dickkopf Wnt signaling pathway inhibitor 3 (DKK3) as a candidate HNSCC-specific molecule that predicts prognosis. Our findings demonstrate that DKK3 expression is significantly elevated in cancer tissues relative to normal tissues and is associated with poor prognosis. Functional analyses have revealed that DKK3 exerts oncogenic effects by activating Akt signaling, driving increased cellular proliferation, migration, and invasion. We validated DKK3 as a potential therapeutic target, and developed complementary peptides to suppress its oncogenic activity. These DKK3 complementary peptides significantly inhibit HNSCC cell proliferation, invasion, and migration at low doses without detectable side effects and, in certain aspects, displayed superior performance over conventional HNSCC treatments including cisplatin and cetuximab. Conclusions Peptide-based drug discovery, also referred to as medium-molecular-weight drug discovery, has attracted increasing attention, although few agents have reached clinical application. Our DKK3 complementary peptides are promising novel candidate therapeutics for HNSCC, raising expectations for future translational and clinical developments.
BACKGROUND:Necrotizing sialometaplasia (NSM) is a benign, self-limiting salivary gland lesion that closely mimics malignancy. Beyond its diagnostic relevance, NSM provides a valuable model for investigating how salivary epithelial cells and stromal fibroblasts respond to acute microenvironmental stress. HIGHLIGHT:Advances in histopathology, together with the development of salivary gland-derived organoids and formalin-fixed paraffin-embedded (FFPE) organoid protocols, provide a robust platform for studying epithelial-stromal interactions in the oral cavity. Salivary gland organoids recapitulate the key architectural and functional features of native tissue, enabling controlled exposure to inflammatory cytokines and hypoxia. The subsequent development of an FFPE-compatible organoid protocols permits routine hematoxylin and eosin and immunohistochemical staining of three-dimensional cultures, facilitating direct comparison with human specimens. Using these approaches, recent studies have demonstrated that fibroblast-derived transforming growth factor-β3 (TGF-β3) suppresses salivary epithelial proliferation and induces squamous metaplasia. Meanwhile, hypoxic stress preferentially injures acinar cells while sparing myoepithelial and basal cells, which subsequently become sources of TGF-β3 in early NSM-like lesions. Collectively, these findings connect established etiological concepts, such as ischemia and trauma, to defined molecular and cellular mechanisms. CONCLUSION:This review summarizes salivary gland organoid technology and FFPE-based analytical methods and integrates organoid-derived evidence with histopathological observations to propose a stepwise model of NSM pathogenesis driven by hypoxia-induced acinar injury and TGF-β3-mediated epithelial metaplasia.
