Cancer cachexia is associated with poor clinical outcomes in lung cancer patients; however, its economic impact in Japan remains largely uncharacterized. This study quantified the incremental healthcare costs associated with cachexia in Japanese lung cancer patients using nationwide claims data. We conducted a retrospective cohort study using the Japan Medical Data Center Claims Database. Deceased lung cancer patients were classified into cachexia (n = 447) and control (n = 10464) groups based on International Classification of Diseases, 10th Revision diagnosis codes. Between-group cost differences were assessed using generalized linear models with a gamma distribution, adjusting for survival time, demographics, histology, metastasis, and comorbidities. Within-patient cost changes were analyzed using fixed-effects regression, comparing 6-month periods before and after cachexia diagnosis. Cachexia was independently associated with 13.5% higher total medical costs (rate ratio: 1.14, 95% confidence interval [CI]: 1.06–1.21, p < 0.001). Within-patient analysis demonstrated a 57.9% cost increase in the month of diagnosis (from ¥371360 to ¥586405), with costs remaining 21.7% elevated post-diagnosis. Cost composition shifted from procedures (1.3 vs. 5.4%) toward home care (8.6 vs. 5.7%) in cachexia patients. Median survival following cachexia diagnosis was only 1.0 month, with 71% of patients dying within 3 months. Anamorelin use increased from 2.4 to 29.8% post-diagnosis, although 70.2% of patients did not receive this therapy. Cachexia diagnosis in lung cancer patients is associated with substantial cost increases in Japan. The extremely short survival after diagnosis and the shift toward supportive care highlight the need for earlier recognition and intervention. These findings provide essential data for the economic evaluation of cachexia therapies.

Muscle atrophy induced by prolonged inactivity (disuse), including denervation-induced atrophy, is accompanied by oxidative stress, inflammation, and dysregulated protein turnover, yet no effective pharmacological therapy is currently available. Cannabidiol (CBD), a non-psychoactive phytocannabinoid derived from Cannabis sativa, has been reported to exhibit anti-inflammatory and antioxidant properties; however, its potential involvement in disuse-related muscle atrophy has not been fully characterized. In this study, to evaluate the potential effects of CBD on disuse-related muscle atrophy, we employed both in vivo and in vitro models. A mouse model of sciatic nerve resection–induced muscle atrophy was used for the in vivo experiments, while C2C12 myotubes were utilized for the in vitro analyses. In the denervated mouse model, CBD attenuated the decrease in muscle mass in the tibialis anterior and gastrocnemius muscles, as well as the decline in treadmill running performance. CBD also reduced oxidative stress and suppressed the denervation-induced upregulation of Atrogin-1 and muscle RING-finger 1 (MuRF1) proteins, as well as tumor necrosis factor-α (TNF-α) mRNA. Furthermore, CBD partially restored the decreased mitochondrial markers observed following denervation. In vitro, CBD similarly suppressed MuRF1 and Atrogin-1 protein levels and TNF-α mRNA expression in C2C12 myotubes. These findings suggest that CBD is associated with protective effects against disuse-related muscle atrophy, accompanied by reductions in oxidative stress markers, alterations in proteolytic pathways, and changes in mitochondrial-related markers. This study highlights a previously underexplored biological effect of a natural phytocannabinoid and supports further investigation of CBD as a potential supportive strategy for disuse-related muscle wasting.

Magnesium deficiency (MgD) disrupts numerous physiological processes, yet its specific impact on in vivo glucose homeostasis remains unclear. This study investigated the longitudinal effects of MgD on blood glucose dynamics in freely moving rats using continuous glucose monitoring. Animals were maintained on a 2–3-week MgD or Control diet under two conditions: access to standard drinking water or a 10% glucose solution. Under standard drinking water conditions, MgD rats exhibited significantly lower mean blood glucose levels specifically during the quiescent day phase, although nonlinear fluctuation patterns remained comparable to those of controls. Conversely, when provided with the glucose solution, MgD rats increased fluid intake, exhibiting a behavioral compensation that normalized mean glucose levels despite the hypoglycemic tendency. However, detailed time-series analysis utilizing recurrence plots revealed that this compensation coincided with altered dynamics; MgD rats exhibited significant impairment in the periodicity of glucose fluctuations during the day phase under the glucose-challenge condition, indicating disrupted blood glucose homeostasis. These findings suggest that chronic MgD lowers baseline glucose levels, potentially via enhanced insulin secretion, thereby further compromising glucose stability under metabolic challenge. This study highlights the important role of magnesium (Mg) in maintaining circadian glucose rhythmicity and pancreatic functional integrity. Consequently, we propose the synergistic application of Mg assays and continuous glucose monitoring as biomarkers for metabolic disorders.

We recently demonstrated that aromatic (ar)-turmerone analogs ((E)-5-methyl-1-(p-tolyl)hexa-1,4-dien-3-one [A2] and (E)-1-(4-methoxyphenyl)-5-methylhexa-1,4-dien-3-one [A4]) activate chaperone-mediated autophagy (CMA), a pathway in the autophagy-lysosome protein degradation system, in SH-SY5Y cells. Our previous studies revealed that the impairment of CMA and microautophagy (mA), another autophagy-related pathway, and dendritic shrinkage were observed in primary cultured Purkinje cells (PCs) expressing causal proteins of spinocerebellar ataxia (SCA), an autosomal dominant neurodegenerative disease. In the present study, we first investigated the effects of A2 and A4 on lysosomal protein degradation and dendritic morphology in cerebellar primary cultured PCs. Both compounds enhanced dendritic development and activated CMA in cultured PCs. These effects were significantly suppressed by the inhibitors of nuclear factor erythroid 2-related factor 2 and p38. We next examined the effects of A2 and A4 on PCs expressing several types of SCA-causing proteins (SCA model PCs). Both chemicals ameliorated the dendritic shrinkage and restored the decreased CMA/mA activity in several SCA model PCs. These findings suggest that the ar-turmerone analogs A2 and A4 improve the in vitro phenotype of SCA model PCs through CMA activation, highlighting the therapeutic potential of these analogs for various types of SCAs.

Mitochondrial L-2-hydroxyglutarate dehydrogenase (L2HGDH) is a FAD-containing membrane protein that oxidizes L-2-hydroxyglutarate (L-2-HG) to 2-oxoglutarate (2-OG). L2HGDH dysfunction is associated with human diseases, such as neurometabolic disorders and cancer. Recently, the first crystal structure of Drosophila melanogaster L2HGDH (DmL2HGDH) bound with FAD and 2-OG was reported. Structural analysis, together with mutagenesis and activity measurements, revealed the oxidation mechanism of L-2-HG. However, the physiologically relevant electron acceptor has not yet been elucidated. While bacterial L2HGDH has been proposed to reduce ubiquinone, this remains controversial. To understand the full reaction mechanism of L2HGDH, identification of the electron acceptor and characterization of its interaction with the enzyme are necessary. In this study, we demonstrate that DmL2HGDH transfers electrons from L-2-HG to decylubiquinone, a ubiquinone analog that is sparingly soluble in aqueous buffers and used for in vitro studies. The reaction was moderately inhibited by ferulenol, which inhibits some quinone reductases, including the homologous enzyme malate–quinone oxidoreductase (MQO). Interestingly, the observed kinetic behavior differs from that of MQO. Using AlphaFold3 and molecular dynamics, we provide insights into the interaction between DmL2HGDH and ubiquinone and propose a mechanism for ubiquinone reduction.

Teicoplanin is an important antibiotic for methicillin-resistant Staphylococcus aureus infections. To enhance its clinical effectiveness while preventing adverse effects, therapeutic drug monitoring (TDM) of teicoplanin trough concentration is recommended. Given the importance of the early attainment of therapeutic concentrations for treatment success, initial dosing regimens, including loading and maintenance doses, are deliberately designed based on patient information. However, initial dose planning for teicoplanin strongly relies on clinician expertise. This study aimed to use a machine learning (ML) approach to integrate clinicians’ knowledge into a predictive model for initial teicoplanin dose planning. First, we confirmed that dose planning by pharmacists specialized in TDM (TDM pharmacists) significantly improved early therapeutic target attainment for patients who were not admitted to intensive or high care units. Subsequently, we used a dataset of initial teicoplanin dose plans created by TDM pharmacists to train the model that emulates their dosing decision-making process. Although the prediction accuracies of the ML model were modest (45.8 and 66.7% for the loading and maintenance doses, respectively), the model successfully learned the basic policy of dose planning, suggesting that ML approaches have potential utility in supporting appropriate initial teicoplanin treatment.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease marked by inflammation of the colon. Although various dextran sulfate sodium (DSS)-induced UC models are available, the traditional free-drinking model involves oral administration, which complicates the assessment of extracolonic organs because of widespread intestinal exposure. This study aimed to create a localized UC model through rectal administration of DSS and evaluate whether this approach minimized direct DSS exposure to the small intestine and liver. Rats received 40% DSS rectally for 13 d. Changes in body weight, Disease Activity Index, and histological scores were monitored. The effects of 5-aminosalicylic acid treatment were examined, and small intestinal morphology, inflammatory markers, bile flow, and mRNA levels of hepatic bile salt export pump were analyzed. Rectal DSS induced localized inflammation in the distal colon and rectum, mimicking key features of UC such as weight loss, mucosal injury, and elevated disease activity. Some of these effects were partially alleviated by 5-aminosalicylic acid treatment. The small intestine shortened without infiltration of inflammatory cells or cytokine increase, indicating a non-inflammatory structural change. Bile flow and hepatic bile salt export pump expression significantly decreased in DSS-treated rats, suggesting hepatobiliary excretory dysfunction. Overall, the rectal DSS model offers a controlled and reproducible way to induce colon-specific inflammation, overcoming the limitations of the free-drinking model, which hinders extracolonic evaluation due to oral DSS exposure. This model may provide a research basis for further study of inter-organ interactions, particularly gut–liver axis dysfunction and intestinal barrier-related drug absorption in UC.

Sotorasib is a molecularly targeted drug that exerts antitumor effects by selectively binding to KRAS G12C through a Michael addition reaction, irreversibly inhibiting KRAS. However, the frequent occurrence of adverse events, such as gastrointestinal and hepatic disorders, has raised major concerns. These toxicities are thought to arise from interactions between sotorasib and proteins other than KRAS in normal cells. In this study, we generated a specific antibody against sotorasib and established an immunohistochemical method capable of detecting sotorasib–protein conjugates. Using this technique, we clarified the localization of sotorasib–protein conjugates in the digestive tract of rats, including the duodenum, jejunum, ileum, and colon. Sotorasib–protein conjugates were strongly localized to the villous epithelial cells of the small intestine but were scarcely detected in the colon, highlighting regional differences. This study elucidates the localization of sotorasib–protein conjugates in the gastrointestinal tract of rats and provides important insights into the mechanisms underlying sotorasib-induced gastrointestinal disorders.

Abortion remains a significant public health concern and often results from unintended pregnancies. Although abortion rates have declined, approximately 40% are still due to unplanned pregnancies. We conducted a subanalysis of the FIKA study, a survey on sexuality among Japanese women aged 18–45 years, to examine factors correlated with abortion. We analyzed responses obtained from 3228 sexually experienced women, who were categorized based on abortion history. Sources of knowledge about intercourse and contraceptives were assessed using a standardized questionnaire. A decision tree analysis was performed to identify associated risk factors. Among the participants, 410 women (12.7%) had undergone an abortion. Women who had undergone an abortion were significantly more likely to rely on friends as a source of contraceptive information than women who had not had an abortion (p = 0.0024). Participants with abortion experience showed greater variation in knowledge about contraceptive scores, with most of them being in the lowest knowledge group. Decision tree analysis revealed two key factors: sexual debut before the age of 17 years and only compulsory education. The abortion rate was 39.5% among women with both factors, compared to 7.9% among those with none. Early sexual initiation and limited education were strongly associated with abortion experience. Reliance on informal sources may also contribute to a poor understanding of reproductive health. These findings underscore the need for early, comprehensive, and formal sex education to improve sexual literacy and reduce unintended pregnancies.

Subjective adverse events (AEs), such as pain, are often under-recognized when relying solely on structured data. Although natural language processing (NLP) enables the extraction of AEs from narrative electronic health records (EHRs), interpretation of their temporal dynamics is difficult. Visualization methods can bridge this gap by transforming text-derived symptom data into clinically interpretable data. This study aimed to demonstrate the clinical value of a framework integrating NLP-based AE extraction with time-series visualization for otherwise invisible symptoms. Narrative texts, including progress notes, nursing records, and discharge summaries, were processed using MedNERN-CR-JA, a pretrained Japanese BERT-based model for entity recognition. AEs were visualized using Kaplan–Meier curves to represent the time to first onset and heatmaps, displaying all subsequent symptom documentation alongside supportive medication use. Among the 35042 eligible patients, 3094 received paclitaxel (PTX) and were matched to 3094 controls. PTX was associated with a higher risk of musculoskeletal symptoms (hazard ratio, 1.77; 95% confidence interval: 1.57–1.99). Kaplan–Meier curves showed earlier onset in PTX recipients, while heatmaps depicted recurrent documentation and the corresponding analgesic use. Restricting the analyses to the triweekly PTX regimen reduced the heterogeneity between inpatient and outpatient documentation and revealed a clearer alignment between the treatment cycles and acute symptom onset. This framework demonstrates the clinical value of visualizing NLP-extracted AEs from narrative EHRs, improving the resolution of subjective AE data, enhancing monitoring, and supporting patient-centered care and clinical decision making through complementary time-to-event and heatmap visualizations.

To clarify the roles of Ca_v3.2 T-type Ca²⁺ channels and endogenous estrogen in pruritus, we conducted a fundamental study employing mice and clinical cross-sectional analyses of pharmacy claims data. In mice, intradermal injection of sulfide (Na₂S), a Ca_v3.2 enhancer, caused itch responses, an effect blocked by KTtp38, a T-type Ca²⁺ channel inhibitor, and deletion of Ca_v3.2 gene. KTtp38 also suppressed itch responses following intradermal histamine or chloroquine. The sulfide-induced itch responses in female mice decreased by ovariectomy and/or repeated treatment with letrozole, an aromatase inhibitor. Cross-sectional analyses of pharmacy claims data of 357972 female patients aged 18 years and older, obtained from nationwide branches of a chain pharmacy group, showed significantly lower prescription rates of topical steroids used for treatment of pruritus and/or dermatitis in women 55 years and older than in women under 55 years, and in the users than non-users of estrogen suppressants. Multivariate logistic regression analysis in the users and non-users of estrogen suppressants after propensity score matching indicated significant negative association of topical steroid prescription with the use of estrogen suppressants. Together, the present fundamental and clinical studies suggest the involvement of Ca_v3.2 and the promotive role of estrogen in pruritus in mice and/or humans.

Chemotherapy-induced oral mucositis is a frequent and debilitating adverse effect that impairs nutritional status and interrupts cancer therapy. Although 5-fluorouracil-induced animal models of oral mucositis are well established, irinotecan, widely used for colorectal, lung, and pancreatic cancers, has also been associated with oral mucosal injury; however, no standardized preclinical model exists. This study aimed to establish a reproducible hamster model of irinotecan-induced oral mucositis and evaluate the prophylactic and therapeutic efficacy of topical hangeshashinto (HST) compared with dexamethasone. Male Syrian hamsters received intraperitoneal irinotecan (100, 150, or 200 mg/kg) on Day 0, followed by localized mucosal injury induced by 50% acetic acid. Ulcer area, body weight, histopathology, peripheral blood count, and myeloperoxidase (MPO) activity were evaluated. HST (10% aqueous solution) or dexamethasone (0.01% elixir) was administered topically once daily either prophylactically (Days −3 to 0) or therapeutically (from Day 0 onward). Ulcer area increased in a dose-dependent manner, peaking on Day 4. The 200 mg/kg dose yielded consistent lesion formation with transient weight loss. Histopathological examination revealed dense neutrophilic infiltration and epithelial disruption. MPO activity was significantly elevated on Days 4 and 7. Prophylactic HST significantly reduced the peak and cumulative ulcer areas, whereas dexamethasone delayed healing. The 200 mg/kg irinotecan plus acetic acid hamster model thus provides a reliable platform for investigating oral mucositis. HST, particularly when administered prophylactically, exhibited better efficacy than dexamethasone, potentially through modulation of inflammatory responses and attenuation of oxidative stress. This model may facilitate further mechanistic studies and the development of preventive strategies for chemotherapy-induced oral mucositis.

In the development of pharmaceuticals and other chemical substances, it is important to evaluate their efficacy and safety. There is a growing trend toward reducing reliance on traditional in vivo testing using animals for safety assessments and utilizing new evaluation methods, such as in vitro and in silico testing, to refine human safety assessments. Furthermore, in medical and environmental fields, there is a growing demand for the utilization of vast amounts of information. This has led to the development of data-driven approaches that utilize large-scale medical information and artificial intelligence (AI). Machine learning enables computers to learn from known data, discover new patterns, and predict unknown data. This technology is also useful for in silico prediction of chemical toxicity and adverse reactions in humans. Recently, explainable AI, which presents the basis for forecasts obtained from machine learning models in a user-understandable manner, has attracted attention and is a useful technology for decision-making support. We have developed machine learning models focusing on a quantitative structure–activity relationship approach to predict toxicity and adverse reactions based on the structural information of chemical substances. Furthermore, we have begun to develop a model to predict package insert revisions based on post-marketing adverse reaction information. These efforts will contribute to solving regulatory science issues regarding the appropriate use of chemical substances such as pharmaceuticals.

Disruption of osteoblast differentiation can lead to severe bone diseases, such as osteoporosis and osteosclerosis. Our previous study showed that a reduced 4S/6S ratio promotes osteoblast differentiation, linking this specific chondroitin sulfate (CS) modification to bone pathology. This study investigated the effect of forced elevation of the 4S/6S ratio on differentiation. C4ST-1 was found to exhibit overexpression, increasing the 4S/6S ratio, significantly suppressing osteoblast differentiation, as evidenced by reduced Akp2 gene expression and ALP activity. This inhibition was far more potent than that caused by the enzymatic removal of CS. Notably, treating C4ST-1-overexpressing cells with chondroitinase reduced differentiation inhibition to a level similar to that in mock cells treated with chondroitinase. These results suggest that the strong inhibition was due to the excessive 4-sulfated CS produced by C4ST-1, implying a mechanism distinct from the inhibition caused by a lack of CS. To elucidate this mechanism, we investigated the potential feedback loop. The increase in 4-sulfated CS from C4ST-1 overexpression enhanced Wnt3a expression, which upregulated p53 expression. Pharmacological inhibition of β-catenin and p53 partially restored Akp2 expression, confirming their roles as key mediators. We propose that a high 4S/6S ratio activates a Wnt/β-catenin-p53 axis, where p53 acts as a brake on differentiation. Our findings highlight the critical role of CS sulfation patterns in fine-tuning the osteoblast fate.

Triple-negative breast cancer (TNBC) is characterized by the absence of hormone receptors and human epidermal growth factor receptor 2 (HER2) expression, rendering hormone therapy and HER2-targeted treatments ineffective. Consequently, conventional chemotherapy remains the primary therapeutic option, despite its severe side effects and poor prognosis. Hybrid liposomes (HL) composed of phospholipids and polyethylene glycol (PEG)-based surfactants have been reported to have therapeutic effects on various cancers without containing anticancer drugs. In this study, we investigated whether photodynamic therapy (PDT) with HL containing indocyanine green (HL/ICG) enhanced the therapeutic effect of HL alone in a mouse model of subcutaneous implantation of triple-negative breast cancer (TNBC) cells in vivo. HL/ICG selectively accumulated in tumors in mice implanted with 4T1-Luc cells, a TNBC cell line. Histological analysis of resected tumor tissues following HL/ICG-mediated PDT revealed a significant increase in cells positive for oxidative stress markers, indicating elevated intracellular oxidative damage. Additionally, a marked presence of apoptotic cells was observed, suggesting that PDT effectively induced programmed cell death in tumor tissues. These results indicate that PDT with HL/ICG induces oxidative stress-mediated apoptosis in tumors derived from 4T1-Luc cells and significantly enhances the therapeutic efficacy of HL alone in vivo, highlighting its potential as a promising strategy for the treatment of TNBC.

Recently, “readthrough compounds” have attracted attention as a promising approach to treat human hereditary diseases caused by nonsense mutations. These compounds enable ribosomes to bypass a premature termination codon (PTC) introduced into mRNA by a nonsense mutation, thereby restoring the expression of full-length functional proteins. We performed a structure–activity relationship study focusing on (+)-negamycin, a known readthrough compound, and identified potent derivatives, TCP-304 and TCP-306, featuring a cyclopropane moiety. In this study, we investigated how the nature of PTCs and their surrounding nucleotide sequences influence the readthrough activity of these negamycin derivatives, using nonsense mutation sequences derived from Duchenne muscular dystrophy and congenital muscular dystrophy genes. In cell-based reporter assay systems, TCP-306 exhibited potent readthrough efficiency against several nonsense mutation sequences containing the TGA-A. Moreover, its sequence preference differed from that of the aminoglycoside G418, a representative readthrough compound that preferentially induces readthrough at TGA-C sequences, suggesting that TCP-306 may serve as an alternative therapeutic option for muscular dystrophies associated with TGA-A nonsense mutations. Overall, this study provides valuable insights for the development of readthrough drugs for hereditary diseases such as muscular dystrophy caused by nonsense mutations.

Adjuvants are co-administered with antigens to enhance vaccine-induced protection. Saponins are plant-derived compounds with adjuvant properties, some of which are used in licensed vaccines. Macrophages and dendritic cells (DCs) exposed to saponin-based adjuvants have been reported to exhibit NLRP3-dependent interleukin-1 beta (IL-1β) release, and NLRP3 signaling has been shown to limit their adjuvant activity. Saponin-based adjuvants also induce plasma membrane rupture (PMR) and the release of high-molecular-weight intracellular molecules; however, the molecular mechanisms that mediate PMR and its impact on adjuvant-induced immune responses remain unclear. Here, we investigated the involvement of Ninjurin-1 (NINJ1), a key executor of PMR, in Quil-A-induced PMR and its immunological consequences. Upon stimulation with the saponin mixture Quil-A, peritoneal macrophages and bone marrow-derived dendritic cells (BMDCs) showed NLRP3-independent PMR but NLRP3-dependent IL-1β release. Quil-A-induced PMR was almost completely suppressed in Ninj1^−/− peritoneal macrophages and BMDCs compared with wild-type cells, whereas IL-1β release remained unaffected by NINJ1 deficiency. Immunization with Quil-A and ovalbumin (OVA) increased OVA-specific serum immunoglobulin G (IgG), IgG2b, and IgG2c levels in Ninj1^−/− mice compared with wild-type mice. Splenocytes from Ninj1^−/− mice produced higher levels of interferon-gamma upon stimulation with class I- and class II-restricted OVA peptides than those from wild-type mice. Ninj1^−/− mice also showed a higher frequency of OVA-bearing cells, particularly monocyte-derived DCs, in the draining lymph nodes. These results demonstrate that NINJ1 is critical for Quil-A-induced PMR and that NINJ1-mediated PMR negatively regulates Quil-A-induced humoral and cellular immune activation by restricting antigen delivery via antigen-presenting cells.

Diabetic nephropathy (DN) is among the most serious diabetes-related microvascular complications, a disease with risks leading to end-stage kidney disease (ESKD). However, only limited DN treatment options are currently available. DN development and progression involve different pathological mechanisms, including inflammation and oxidative stress. Stachybotrys microspora is a fungus producing the triphenyl phenol SMTP-44D, which exhibits anti-inflammatory and antioxidant properties in several disease models. In this study, we aimed to evaluate the effects of SMTP-44D in a DN mouse model, which was created by removing the right kidney of 6-week-old db/db mice. We administered SMTP-44D for 10 weeks between weeks 6 and 16 of age to observe blood glucose levels, renal function parameters, inflammatory factors, oxidative stress markers, and histopathological characteristics. SMTP-44D treatment did not reduce blood glucose level but significantly decreased serum creatinine and urinary albumin as renal function parameters, monocyte chemoattractant protein-1, intercellular adhesion molecule-1, and nicotinamide adenine dinucleotide phosphate oxidase-1 as inflammation and oxidative stress in the kidney. In addition, histopathological assessment revealed its preventive effect against glomerulosclerosis and local regenerative tubule. Therefore, we discovered that SMTP-44D might protect renal function without affecting blood glucose level in DN possibly via suppression of inflammation and oxidative stress. In conclusion, SMTP-44D could be a potential DN treatment agent, even in patients with poor glycemic control.

Immune checkpoint inhibitors (ICIs), essential in cancer therapy, can cause severe immune-related adverse events (irAEs), including myocarditis with a high fatality rate. Currently, the pathogenesis, biomarkers, and risk factors of ICI-induced myocarditis (ICIM) are not fully understood. This exploratory study aimed to develop machine learning-based models to predict the onset of ICIM within 3 months of starting ICI therapy, using a large health insurance database. The models were constructed using the Light Gradient Boosting Machine (LightGBM) and Random Forest algorithms, incorporating clinical variables such as comorbidities and prior medication classifications. In this study, a strategy combining undersampling and bagging was used to minimize the impact of highly imbalanced datasets. The Random Forest model demonstrated superior performance compared with the LightGBM model, and the SHapley Additive exPlanations (SHAP) analysis for the Random Forest model revealed that the concurrent use of ICIs was the most important variable for predictions. Although predictive performance remains limited (AUROC ≈ 0.63), this exploratory framework demonstrates the feasibility of developing data-driven risk prediction models for ICIM. Future studies with expanded datasets and integration of laboratory parameters are warranted to improve predictive accuracy and potential clinical applicability.

Three-dimensional (3D) hepatocyte spheroid cultures offer an advanced in vitro model for investigating liver function and drug metabolism; however, oxygen diffusion limitations restrict spheroid size and functionality. In the present study, we developed a 3D spheroid culture system using HepaRG, a human hepatoma-derived cell line that retains drug-metabolizing enzymes, and oxygen-permeable plates composed of 4-polymethyl-1-pentene (PMP) to improve oxygen availability and metabolic performance. Morphological analysis showed enhanced spheroid circularity and compactness in the PMP culture, implying enhanced cell–cell adhesion. Hypoxic imaging revealed that PMP plate-based cultures markedly reduced central hypoxia, enabling the formation of spheroids with up to 20000 cells. Using clozapine, a low-clearance antipsychotic drug with limited metabolic elimination that is metabolized by monooxygenases, including CYP3A4 and flavin-containing monooxygenase (FMO), we observed an enhanced decline in clozapine levels in PMP plates compared with the clozapine levels seen in the conventional polystyrene plates. Furthermore, the mRNA and protein-expression levels of CYP3A4 and FMO3 were upregulated in the spheroids cultured on PMP plates. These results suggest that improved oxygenation enhances hepatic functionality in 3D cultures by maintaining cell viability and promoting the expression of drug-metabolizing enzymes. Therefore, the PMP plate-based spheroid model offers a practical and physiologically relevant platform for investigating drug metabolism and hepatotoxicity.