Circadian rhythms regulate crucial physiological processes in plants, making the analysis of rhythmic gene expression vital for understanding how plants adapt to and anticipate daily environmental changes, and for improving agricultural traits. Foundational databases for plant circadian rhythms have been invaluable, but face challenges in keeping pace with the rapid accumulation of modern transcriptomic data, particularly for the most widely used model organism, Arabidopsis thaliana. To address this critical gap, we developed GEAR (Gene Expression Archives for Rhythm), a new database resource dedicated to A. thaliana that serves as an integrated atlas of gene expression dynamics. GEAR builds a comprehensive data archive by integrating both legacy microarray and modern RNA-seq datasets, covering 83 diverse experimental conditions. Its intuitive web interface functions as an interactive atlas, allowing users to compare expression profiles not only across different experimental treatments but also across independent studies conducted under nominally identical settings. This unique feature enables researchers to move beyond single-experiment findings and distinguish robust biological signals from interlaboratory variability. For the first time, this allows for a meta-analysis to define a high-confidence set of core clock-regulated genes, providing foundational insights into the most conserved outputs of the plant circadian network.

ABSTRACT Background Small mothers against decapentaplegic homologue 4 (SMAD4) plays an important role in transforming growth factor (TGF)‐β signaling and is associated with various cancers. However, little is known about SMAD4 expression in oral squamous cell carcinoma (OSCC). Aim To investigate the clinical and biological significance of SMAD4 expression in OSCC. Methods and Results Immunohistochemical analysis was performed to detect SMAD4 expression in 90 OSCC specimens obtained from patients who underwent preoperative chemoradiotherapy and surgery (phase II study). We also investigated the correlation between SMAD4 expression and various clinicopathological features. In vitro experiments were performed to assess the effects of SMAD4 expression on chemosensitivity and changes in apoptosis‐related molecules. Notably, low SMAD4 expression was significantly correlated with an increased risk of lymph node metastasis, poor response to chemoradiotherapy, and adverse prognosis in patients with OSCC who underwent preoperative 5‐FU‐based chemoradiotherapy. Additionally, SMAD4 downregulation in OSCC cells decreased sensitivity to cisplatin and 5‐fluorouracil and was associated with an increase in cIAP2 expression. Conclusion The reduced expression of SMAD4 has been linked to both chemotherapy resistance and prognosis in OSCC. However, it may not function as an independent prognostic biomarker. Further research is necessary to determine whether these findings can be generalized to the broader OSCC population.

Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DIHS/DRESS) is a severe form of drug-related rash with distinct features. This condition is characterized by late onset from specific causative drugs, and symptoms worsen despite discontinuation of the causative agent, followed by organ dysfunction. Notably, DIHS/DRESS results from the reactivation of human herpesvirus 6 (HHV-6). Herein, we report a case of DIHS/DRESS in which rash, fever and liver dysfunction were observed during hospitalization for stomatitis, and HHV-6 reactivation was confirmed. A 67-year-old man who had been taking carbamazepine for the sequelae of cerebral hemorrhage was referred to our hospital because of pain in the oral mucosa. Initially, he was diagnosed with a herpes virus infection and treated with acyclovir. Afterward, despite improvement in stomatitis, papules appeared on the trunk of the body and worsened. The symptoms were accompanied by fever and liver dysfunction. Eventually, the patient developed decreased systolic blood pressure, tachypnea, and atrial fibrillation. After pulse steroid therapy was initiated, the patient’s clinical condition improved. Real-time polymerase chain reaction was performed suspecting with DIHS/DRESS, and HHV-6 DNA was detected. Based on this process, we diagnosed the patient with DIHS/DRESS induced by carbamazepine.

The plant circadian clock aligns developmental processes with environmental cycles, a function traditionally attributed to a unified, systemic oscillator. However, this view is challenged by observations that mutations in specific clock genes can cause major developmental phenotypes without a proportional disruption to systemic rhythms. This Hypothesis proposes that clock genes perform dual roles: they act not only as components of the systemic oscillator that generates rhythmicity, but also as specific, contextdependent regulators that control the timing of key developmental events. We argue that this gene-centric perspective extends and refines the classical oscillator model, positing that the pleiotropic nature of clock genes reflects their evolutionary history, whereby transcription factors with pre-existing developmental roles were co-opted for timekeeping. Understanding this functional duality - how individual clock components are deployed in specific tissues and conditions - offers a new perspective for dissecting the complex interplay between timekeeping and development.

Objective This study aimed to identify and evaluate the diagnostic potential of exosome-derived microRNAs (miRNAs) for the early detection of occult neck metastasis (ONM) in tongue squamous cell carcinoma (TSCC), a significant postoperative challenge. Methods Serum samples collected from 12 patients pre-treatment were divided into two groups: Cohort A: patients with cT1-2N0 TSCC who underwent transoral partial glossectomy alone and occurred (n=3) or did not occur ONM (n=3); Cohort B: patients with cN0 TSCC who underwent elective neck dissection (END) and diagnosed (n=3) or did not diagnose pathological lymph node metastasis (n=3). Exosomal miRNA was extracted for miRNA microarray analysis to identify candidate miRNAs, and the diagnostic potential was assessed using preoperative serum samples in 45 patients with cT1-2N0 TSCC who underwent transoral partial glossectomy. Real-time quantitative RT-PCR validated the expression of candidate miRNAs. Univariate analysis was used to evaluate the association between miR-1290 expression and clinicopathological factors. The log-rank test and multivariate Cox proportional hazards regression analysis was used to investigate clinicopathological risk factors, including miRNAs. Results Microarray and ROC analyses identified miR-1290 as a potential ONM biomarker. Univariate analysis indicated a significant correlation between miR-1290 expression and the clinical depth of invasion. Although miR-1290 was significantly associated with ONM occurrence in the log-rank test, the multivariate analysis with established ONM predictors did not reach statistical significance. Conclusions Exosome-derived miR-1290 may serve as a potential biomarker for ONM in patients with early stage TSCC, aiding END. However, larger prospective observational studies are needed to confirm this hypothesis.

Squamous cell carcinoma of the buccal mucosa (SCCBM) is a prevalent malignancy of the oral cavity with high morbidity and mortality rates. The pterygomandibular raphe (PMR) connects the oral cavity, pharynx, and masticator space, serving as a key anatomical landmark during surgical resection. However, PMR invasion into SCCBM remains poorly understood. This study assessed the prognostic significance of PMR invasion in patients with resectable SCCBM. The study included 82 patients with SCCBM, excluding those with T4b, who underwent radical resection at Kumamoto University Hospital between 2000 and 2017. Patients were categorized into three groups based on PMR invasion patterns: non-contact, contact, and invasion. The relationship between PMR invasion and clinicopathological characteristics was analyzed using the Fisher’s exact test. The Kaplan–Meier method, log-rank test, and propensity score-matched analyses were used for survival analysis. Contact or invasion into the PMR was significantly associated with advanced clinical T and N stages, clinical stage, endophytic growth pattern, high-grade invasion pattern, and poor tumor differentiation. Patients with PMR invasion had a higher proportion of recurrences in the buccal subcutaneous, mandibular, and masticator spaces. Univariate analysis indicated that contact- or invasion-type PMR invasion predicted worse overall survival (OS). The impact of PMR invasion on OS was confirmed using a propensity score-matched analysis. This study revealed that PMR invasion is a potential novel grading and prognostic factor for resectable SCCBM, with significance in planning the extent of SCCBM resection.

Introduction: Immune checkpoint inhibitors (ICIs) have been clinically used to treat various cancers. This has resulted in a paradigm shift in the treatment of cancers, including recurrent/metastatic oral squamous cell carcinoma (R/M OSCC); however, response rate to treatment with ICIs is limited to 20-30%, and the treatment efficacy varies among patients. Therefore, developing a stratification method to accurately select patients expected to respond to the treatment would be beneficial. Extracellular vesicles (EVs) are important mediators of intercellular communication. Notably, programmed death-ligand 1 (PD-L1) is expressed on the surface of EVs in several malignancies. Herein, we focused on the clinical significance of PD-L1-expressing EVs (PD-L1 EVs) circulating in the serum of patients with R/M OSCC treated with ICIs. Methods: Overall, 37 patients with R/M OSCC who were treated with ICIs at our institution were evaluated, and the optimum cutoff level of PD-L1 EVs was determined using a receiver operating characteristic analysis. Furthermore, we evaluated the association between PD-L1 EV levels and various clinicopathological features as well as the effects of PD-L1 EVs status on prognosis. Results: The optimum cutoff level of PD-L1 EVs was 2.90 ng/mL. Further, Kaplan-Meier curve analysis revealed that high PD-L1 EV level was significantly associated with poor overall survival. Moreover, multivariate analysis indicated that high PD-L1 EV level was independently correlated with poor 5-year overall survival. Conclusion: These findings indicate that assessing levels of PD-L1 EVs in serum before treatment may be a valuable prognostic indicator for patients with R/M OSCC following ICIs treatment.

This retrospective study assessed the prognostic significance of pterygomandibular raphe (PMR) invasion in resectable squamous cell carcinoma of the buccal mucosa (SCCBM). We included 82 patients with SCCBM who underwent radical resection at Kumamoto University Hospital between 2000 and 2017. Patients were categorized into three groups based on PMR invasion patterns: noncontact, contact, and invasion. The relationship between PMR invasion and clinicopathological characteristics was analyzed using Fisher’s exact test. The Kaplan–Meier method, log-rank test, and Cox regression model were employed for survival analysis. Results indicated that contact or invasion into the PMR was significantly associated with advanced clinical T and N stages, clinical stage, endophytic growth pattern, high-grade invasion pattern, poor tumor differentiation, extranodal extension, and distant metastasis. Patients with PMR invasion experienced a significantly higher proportion of recurrences in the buccal, subcutaneous, mandibular, and masticatory spaces. Univariate analysis indicated that PMR invasion by contact or invasion type SCCBM was a predictor for worse local control rate, disease-free survival, and overall survival, while multivariate analysis revealed that it was an independent worse prognostic factor for overall survival. Thus, PMR invasion is a key prognostic factor in resectable SCCBM.

The circadian clock allows plants to anticipate and adapt to periodic environmental changes. Organ- and tissue-specific properties of the circadian clock and shoot-to-root circadian signaling have been reported. While this long-distance signaling is thought to coordinate physiological functions across tissues, little is known about the feedback regulation of the root clock on the shoot clock in the hierarchical circadian network. Here, we show that the plant circadian clock conveys circadian information between shoots and roots through sucrose and K+. We also demonstrate that K+ transport from roots suppresses the variance of period length in shoots and then improves the accuracy of the shoot circadian clock. Sucrose measurements and qPCR showed that root sucrose accumulation was regulated by the circadian clock. Furthermore, root circadian clock genes, including PSEUDO-RESPONSE REGULATOR7 (PRR7), were regulated by sucrose, suggesting the involvement of sucrose from the shoot in the regulation of root clock gene expression. Therefore, we performed time-series measurements of xylem sap and micrografting experiments using prr7 mutants and showed that root PRR7 regulates K+ transport and suppresses variance of period length in the shoot. Our modeling analysis supports the idea that root-to-shoot signaling contributes to the precision of the shoot circadian clock. We performed micrografting experiments that illustrated how root PRR7 plays key roles in maintaining the accuracy of shoot circadian rhythms. We thus present a novel directional signaling pathway for circadian information from roots to shoots and propose that plants modulate physiological events in a timely manner through various timekeeping mechanisms.

Plants adapt to periodic environmental changes, such as day and night, by using circadian clocks. Cell division and elongation are primary steps to adjust plant development according to their environments. In Arabidopsis, hypocotyl elongation has been studied as a representative model to understand how the circadian clock regulates cell elongation. However, it remains unknown whether similar phenomena exist in other organs, such as roots, where circadian clocks regulate physiological responses. Here, we show that root hair elongation is controlled by both light and the circadian clock. By developing machine-learning models to automatically analyze the images of root hairs, we found that genes encoding major components of the central oscillator, such as TIMING OF CAB EXPRESSION1 (TOC1) or CIRCADIAN CLOCK ASSOCIATED1 (CCA1), regulate the rhythmicity of root hair length. The partial illumination of light to either shoots or roots suggested that light received in shoots is mainly responsible for the generation of root hair rhythmicity. Furthermore, grafting experiments between wild-type (WT) and toc1 plants demonstrated that TOC1 in shoots is responsible for the generation of root hair rhythmicity. Our results illustrate the combinational effects of long-distance signaling and the circadian clock on the regulation of root hair length.

Radioresistance is a major obstacle to the successful treatment of oral squamous cell carcinoma (OSCC). To help overcome this issue, we have developed clinically relevant radioresistant (CRR) cell lines generated by irradiating parental cells over time, which are useful for OSCC research. In the present study, we conducted gene expression analysis using CRR cells and their parental lines to investigate the regulation of radioresistance in OSCC cells. Based on gene expression changes over time in CRR cells and parental lines subjected to irradiation, forkhead box M1 (FOXM1) was selected for further analysis in terms of its expression in OSCC cell lines, including CRR cell lines and clinical specimens. We suppressed or upregulated the expression of FOXM1 in OSCC cell lines, including CRR cell lines, and examined radiosensitivity, DNA damage, and cell viability under various conditions. The molecular network regulating radiotolerance was also investigated, especially the redox pathway, and the radiosensitizing effect of FOXM1 inhibitors was examined as a potential therapeutic application. We found that FOXM1 was not expressed in normal human keratinocytes but was expressed in several OSCC cell lines. The expression of FOXM1 was upregulated in CRR cells compared with that detected in the parental cell lines. In a xenograft model and clinical specimens, FOXM1 expression was upregulated in cells that survived irradiation. FOXM1-specific small interfering RNA (siRNA) treatment increased radiosensitivity, whereas FOXM1 overexpression decreased radiosensitivity, and DNA damage was altered significantly under both conditions, as well as the levels of redox-related molecules and reactive oxygen species production. Treatment with the FOXM1 inhibitor thiostrepton had a radiosensitizing effect and overcame radiotolerance in CRR cells. According to these results, the FOXM1-mediated regulation of reactive oxygen species could be a novel therapeutic target for the treatment of radioresistant OSCC; thus, treatment strategies targeting this axis might overcome radioresistance in this disease.

Objective: Oral and maxillofacial surgeons commonly encounter dentigerous cysts (DCs) in clinical practice. If the DC is large and involves vital structures, such as the inferior alveolar nerve, marsupialization can be a useful treatment option to reduce the cyst size, ensuring safer enucleation later. However, the process of postoperative cyst shrinkage remains largely unknown. We used three-dimensional (3D) computed tomography (CT) to ana-lyze volumetric changes occurring in DCs after marsupialization. In addition, we evaluated several parameters that might influence the efficiency of volume reduction.Methods: This retrospective cohort study included 21 patients with mandibular DCs in the third molar region. Using 3D CT data obtained before and after marsupialization, we measured cyst volumes at approximately 6 and 12 months after marsupialization.Results: All lesions gradually shrank after marsupialization. The relative velocity of volume reduction differed significantly between 6 and 12 months after marsupialization. Age was significantly related to the efficiency of cyst shrinkage at 12 months after marsupialization. The efficiency of cyst shrinkage was not correlated with sex, smoking status, tooth extraction, or CT values around the lesion.Conclusions: Marsupialization was effective in reducing cyst size in all patients. The efficiency of volume re-duction caused by marsupialization was associated with marsupialization duration and patient age. These factors should be considered during marsupialization and subsequent follow-ups.

Flowering time is an agriculturally important trait that can be manipulated by various approaches such as breeding, growth control and genetic modifications. Despite its potential advantages, including fine-tuning the regulation of flowering time, few reports have explored the use of chemical compounds to manipulate flowering. Here, we report that sulfanilamide, an inhibitor of folate biosynthesis, delays flowering by repressing the expression of florigen FLOWERING LOCUS T (FT) in Arabidopsis thaliana. Transcriptome deep sequencing and quantitative polymerase chain reaction analyses showed that the expression of the circadian clock gene LUX ARRYTHMO/PHYTOCLOCK1 (LUX/PCL1) is altered by sulfanilamide treatment. Furthermore, in the lux nox mutant harboring loss of function in both LUX and its homolog BROTHER OF LUX ARRHYTHMO (BOA, also named NOX), the inhibitory effect of sulfanilamide treatment on FT expression was weak and the flowering time was similar to that of the wild type, suggesting that the circadian clock may contribute to the FT-mediated regulation of flowering by sulfanilamide. Sulfanilamide also delayed flowering time in arugula (Eruca sativa), suggesting that it is involved in the regulation of flowering across Brassicaceae. We propose that sulfanilamide is a novel modulator of flowering.

Nuclear factor erythroid 2-related factor 2 (Nrf2), which regulates the expression of critical antioxidant proteins, was recently demonstrated to play a key role in cancer progression. Resistance to radiotherapy is a major obstacle in treating oral squamous cell carcinoma (OSCC). However, little is known about the association between Nrf2 and radioresistance in OSCC. Two OSCC cell lines (SAS and HSC-2) and their clinically relevant radioresistant (CRR) clones (SAS-R, HSC-2-R) were used. The effects of Nrf2 downregulation on radiosensitivity and the involvement of glycolysis in Nrf2-mediated radioresistance were evaluated. Immunohistochemistry of phosphorylated Nrf2 (p-Nrf2) was performed in 110 patients with OSCC who underwent preoperative chemoradiotherapy and surgery. Nrf2 was stably upregulated in CRR cells in vitro and in a mouse xenograft model. Moreover, elevated Nrf2 expression was associated with radioresistance. The enhancement of Nrf2-dependent glycolysis and glutathione synthesis was involved in the development of radioresistance. Additionally, p-Nrf2 expression was closely related to the pathological response to chemoradiotherapy, and its expression was predictive of prognosis in patients with advanced OSCC. Our results suggest that Nrf2 plays an important role in the radioresistance of OSCC accompanied by metabolic reprogramming. Targeting Nrf2 antioxidant pathway may represent a promising treatment strategy for highly malignant OSCC.

N 6 -isopentenyladenosine (i 6 A), a modified adenosine monomer, is known to induce cell death upon its addition to the culture medium. However, the molecular fate of extracellularly added i 6 A has yet to be identified. Here we show that i 6 A addition to cell culture medium results in i 6 A incorporation into cellular RNA in several cell lines, including the 5-fluorouracil (5-FU)-resistant human oral squamous cell carcinoma cell line FR2-SAS and its parental 5-FU-sensitive cell line SAS. i 6 A was predominantly incorporated into 18S and 28S rRNAs, and i 6 A incorporation into total RNA was mostly suppressed by treating these cell lines with an RNA polymerase I (Pol I) inhibitor. i 6 A was incorporated into RNA even upon inactivation of TRIT1, the only cellular i 6 A-modifying enzyme. These results indicate that upon cellular uptake of i 6 A, it is anabolized to be used for Pol I transcription. Interestingly, at lower i 6 A concentrations, the cytotoxic effect of i 6 A was substantially more pronounced in FR2-SAS cells than in SAS cells. Moreover, in FR2-SAS cells, i 6 A treatment decreased the rate of cellular protein synthesis and increased intracellular protein aggregation, and these effects were more pronounced than in SAS cells. Our work provides insights into the molecular fate of extracellularly applied i 6 A in the context of intracellular nucleic acid anabolism and suggests investigation of i 6 A as a candidate for a chemotherapy agent against 5-FU-resistant cancer cells.

Many attempts have been made to identify the risk factors for postoperative delirium, but this has proved difficult due to its complex morbidity. Furthermore, there is little information on postoperative delirium in patients undergoing tumor resection and reconstructive surgery for oral cancer. The aim of the current study was to investigate the incidence of and risk factors for postoperative delirium in patients undergoing resection and reconstructive surgery for oral cancer. The present study included 104 patients with pedicle or free flap reconstruction. Postoperative delirium developed in 22 (21.2%) of these patients. The mean time to onset of postoperative delirium was 2.5±1.0 days and the duration of delirium was 1.9±1.2 days. Univariate analysis demonstrated that the occurrence of postoperative delirium was significantly correlated with operating time (P=0.033), duration of anesthesia (P=0.039), amount of blood loss (P=0.027), method of reconstruction (P=0.008), type of flap used (P=0.009) and time until postoperative ambulation (P=0.0008). Low postoperative red blood cell count (P=0.004), hemoglobin (P=0.004) and hematocrit (P=0.004) were significantly associated with delirium, but preoperative blood test results were not. The multiple logistic regression analysis of these risk factors revealed that the only significant correlation that remained was between postoperative delirium and the time to ambulation after surgery (P=0.005). Since 2009, the Department of Oral and Maxillofacial Surgery, Kumamoto University Hospital has promoted ambulation after the first two postoperative days for patients with oral cancer undergoing tumor resection with reconstruction, and the occurrence of postoperative delirium has decreased from 29.2 to 14.0%. The results of the current study suggest that early postoperative ambulation in patients who undergo reconstructive surgery for oral cancer is effective for preventing postoperative delirium.