1.Molecular and Phenotypic Characterization of Fluid-Derived Patient-Derived Cell and Organoid Models in Advanced Gastric Cancer
Ye Jin MOON ; Woo Sun KWON ; Chan Hee PARK ; Jinsoo JANG ; Juin PARK ; Byeong Gyu YOON ; Han Byeol MUN ; Namju KIM ; Choong-kun LEE ; Hei Cheul JEUNG ; Su-Jin SHIN ; Tae Soo KIM ; Sun Young RHA
Journal of Gastric Cancer 2026;26(2):260-278
Purpose:
Patient-derived cells (PDCs) and patient-derived organoids (PDOs) are complementary preclinical models widely used in translational cancer research. However, their molecular and functional differences have not been systematically characterized. This study established and analyzed paired PDC and PDO models derived from the same gastric cancer ascites to delineate platform-dependent molecular and functional profiles.
Materials and Methods:
Malignant ascites or pleural fluid obtained from 6 patients with advanced gastric cancer were used to establish paired PDC and PDO models. All pairs underwent comprehensive multi-omics profiling, integrating genomic, transcriptomic, and proteomic data. Phenotypic characterization included morphological, histological, proliferative, and cell cycle analyses. Drug sensitivity assays were performed using 4 chemotherapeutic agents commonly used to treat gastric cancer.
Results:
The 6 paired PDC and PDO models exhibited distinct morphological characteristics.Whole-genome analyses demonstrated high concordance among primary tumors, PDCs, and PDOs, confirming tumor representation across platforms. Multi-omics profiling identified platform-dependent molecular signatures; PDOs were enriched for extracellular matrix remodeling and stemness, whereas PDCs displayed proliferation- and immune-related signatures. Clinically relevant biomarkers, including HER2 and MET alterations, were concordant with primary tumors. Notably, drug responses differed between platforms and patients, indicating platform-dependent and patient-specific chemosensitivity.
Conclusions
Paired PDC and PDO models derived from the same patients preserved core patient-specific tumor characteristics while exhibiting distinct molecular and functional profiles. These findings underscore the culture platform as a critical determinant of experimental outcomes and therapeutic responses. Therefore, careful selection of an appropriate preclinical model is essential to accurately address biological questions and optimize precision oncology strategies.
2.Exploring LEPR-Linked Metabolic Diversity through Gut Microbiome-Metabolome Network Analysis in Non-Obese Adults
Kyeong-Seog KIM ; Joo-Youn CHO ; Ye Chan PARK ; Jang Hee HONG ; Jin-Gyu JUNG ; Jung SUNWOO
Biomolecules & Therapeutics 2026;34(2):448-460
Genetic variation in the leptin receptor (LEPR) gene has been implicated in metabolic regulation, while the gut microbiome and circulating metabolites are increasingly recognized as mediators of host metabolic phenotype. However, the systems-level interactions among LEPR genotypes, gut microbial composition, and serum metabolomic profiles remain poorly understood, particularly in healthy individuals. We conducted a cross-sectional study involving 37 healthy Korean adults. Three LEPR single nucleotide polymorphisms (rs1137101, rs1173100, rs790419) were genotyped. Untargeted metabolomics of fasting serum was performed using gas chromatography–time-of-flight mass spectrometry, and gut microbiome composition was profiled by 16S rRNA gene sequencing. Statistical analysis included principal component analysis, Mann–Whitney U tests, and Spearman correlations. Network analysis integrating microbiome, metabolomic, and clinical phenotype data was conducted using Cytoscape. A total of 54 serum metabolites were identified. LEPR genotypes, particularly rs1137101 and rs1173100, were associated with differences in metabolites such as pimelic acid, malonic acid, and 2,4-dihydroxybutyric acid. Firmicutes negatively correlated with saturated fatty acids and organic acids, whereas Actinobacteria positively correlated with cholesterol and amino acids. Network analysis revealed indole-3-acetate and cholesterol as central nodes linking microbial taxa with body mass index and leptin levels. However, no direct molecular pathways connecting leptin or its receptor were identified. LEPR genetic variation is associated with distinct serum metabolomic patterns and microbiome–host networks in healthy adults. Although no direct leptin signaling links were found, network-level associations suggest indirect genetic influences on metabolic states through microbiome–metabolome interactions.These findings advance understanding of personalized metabolic regulation and gene–microbiome interplay.
3.Impact of Low-Density Lipoprotein Cholesterol Levels on Atherosclerotic Vascular Changes: Analysis of Korean Treat Stroke to Target Trial
Sang Hee HA ; Jae-Chan RYU ; Sung Hee AHN ; Jae-Kwan CHA ; Sang Min SUNG ; Tae-Jin SONG ; Kyung Bok LEE ; Eung-Gyu KIM ; Yong-Won KIM ; Ji Hoe HEO ; Man Seok PARK ; Kyusik KANG ; Byung-Chul LEE ; Keun-Sik HONG ; Oh Young BANG ; Jei KIM ; Jong S. KIM
Journal of Stroke 2026;28(2):330-333
4.Heart Failure Statistics 2025 Update:A Report From the Korean Society of Heart Failure
Chan Joo LEE ; Hokyou LEE ; Kyu-Yong KO ; Min Gyu KONG ; Min Sun KIM ; SungA BAE ; Yuran AHN ; Kyeong-Hyeon CHUN ; Kang-Un CHOI ; Jah Yeon CHOI ; Jungkuk LEE ; Geun U PARK ; Byung Su YOO
International Journal of Heart Failure 2026;8(1):58-73
Background and Objectives:
We evaluated 20-year trends in heart failure (HF) epidemiology in Korea to quantify changes in its burden from 2002 to 2023.
Methods:
A nationwide analysis was conducted using a random 50% sample from the Korean National Health Information Database linked to mortality records (2002–2023). HF was defined using diagnostic codes recorded as a primary or secondary condition. We calculated crude and age-standardized rates of prevalence, incidence, hospitalization, and mortality. Survival was assessed using the Kaplan–Meier method, stratified by inpatient versus outpatient diagnosis.Trends in heart transplantation and left ventricular assist device implantations were also examined.
Results:
By 2023, approximately 1,750,228 individuals had HF (3.41% prevalence). The age-standardized prevalence has more than doubled from 2002 to 2023. The crude incidence increased over time; the age-standardized incidence remained stable in men and declined in women.Hospitalization rates for any cause or secondary HF diagnoses have increased substantially, whereas primary HF hospitalization rates have remained relatively stable. The annual mortality rate in patients with HF was approximately 6.0% in 2023, being markedly higher in older adults.Although short-term survival has improved, particularly in hospitalized patients, long-term survival remains limited. Use of advanced therapies significantly increased.
Conclusions
The burden of HF in Korea has increased substantially over the past two decades, driven primarily by population aging and improved survival rather than increasing age-adjusted incidence. Despite therapeutic advances, hospitalization and long-term mortality rates remain high, highlighting the need for comprehensive HF strategies in aging societies.
5.Randomized Multicenter Study to Evaluate the Efficacy and Safety of Fexuprazan According to the Timing of Dosing in Patients With Erosive Esophagitis
Sang Pyo LEE ; In-Kyung SUNG ; Oh Young LEE ; Myung-Gyu CHOI ; Kyu Chan HUH ; Jae-Young JANG ; Hoon Jai CHUN ; Joong-Goo KWON ; Gwang Ha KIM ; Nayoung KIM ; Poong-Lyul RHEE ; Sang Gyun KIM ; Hwoon-Yong JUNG ; Joon Seong LEE ; Yong Chan LEE ; Hye-Kyung JUNG ; Jae Gyu KIM ; Sung Kook KIM ; Chong-il SOHN
Journal of Neurogastroenterology and Motility 2025;31(1):86-94
Background/Aims:
Fexuprazan, a novel potassium-competitive acid blocker, was developed for treating acid-related disorders. Pharmacokinetic and pharmacodynamic properties of fexuprazan, unlike those of proton pump inhibitors, are independent of food effect. This study aims to evaluate differences in efficacy and safety of fexuprazan in patients with erosive esophagitis (EE) according to the timing of dosing.
Methods:
In this multicenter, open-label noninferiority study, patients who had typical reflux symptoms with endoscopically confirmed EE were randomized 1:1 to receive fexuprazan 40 mg daily 30 minutes before or after meal. Treatment was completed after 2 weeks or 4 weeks when healing was endoscopically confirmed. The primary endpoint was the proportion of patients with healed EE confirmed by endoscopy up to week 4. Safety endpoints included treatment-emergent adverse events (TEAEs).
Results:
In the prior-to-meal group (n = 89) and after-meal group (n = 86), 4-week EE healing rates were 98.77% and 100.00% (difference, 0.01%; 95% CI, –0.01% to 0.04%) and 2-week EE healing rates were 95.77% and 97.14% (difference, 0.01%; 95% CI, –0.05% to 0.07%), respectively. TEAEs were 9.78% and 8.70% in the prior-to-meal group and the after-meal group, respectively.
Conclusions
Non-inferiority analysis revealed that taking fexuprazan after meal was non-inferior to taking fexuprazan before meals in patients with EE. The frequency of adverse events was similar between the 2 study groups. The drug is safe and effective for healing EE regardless of the timing of dosing.
6.Low-Density Lipoprotein Cholesterol Level, the Lower the Better? Analysis of Korean Patients in the Treat Stroke to Target Trial
Hanim KWON ; Jae-Chan RYU ; Jae-Kwan CHA ; Sang Min SUNG ; Tae-Jin SONG ; Kyung Bok LEE ; Eung-Gyu KIM ; Yong-Won KIM ; Ji Hoe HEO ; Man Seok PARK ; Kyusik KANG ; Byung-Chul LEE ; Keun-Sik HONG ; Oh Young BANG ; Jei KIM ; Jong S. KIM
Journal of Stroke 2025;27(2):228-236
Background:
and Purpose The Treat Stroke to Target (TST) was a randomized clinical trial involving French and Korean patients demonstrating that a lower low-density lipoprotein cholesterol (LDL-C, <70 mg/dL) target group (LT) experienced fewer cerebro-cardiovascular events than a higher target (90–110 mg/dL) group (HT). However, whether these results can be applied to Asian patients with different ischemic stroke subtypes remains unclear.
Methods:
Patients from 14 South Korean centers were analyzed separately. Patients with ischemic stroke or transient ischemic attack with evidence of atherosclerosis were randomized into LT and HT groups. The primary endpoint was a composite of ischemic stroke, myocardial infarction, coronary or cerebral revascularization, and cardiovascular death.
Results:
Among 712 enrolled patients, the mean LDL-C level was 71.0 mg/dL in 357 LT patients and 86.1 mg/dL in 355 HT patients. The primary endpoint occurred in 24 (6.7%) of LT and in 31 (8.7%) of HT group patients (adjusted hazard ratio [HR]=0.78; 95% confidence interval [CI]=0.45–1.33, P=0.353). Cardiovascular events alone occurred significantly less frequently in the LT than in the HT group (HR 0.26, 95% CI 0.09–0.80, P=0.019), whereas there were no significant differences in ischemic stroke events (HR 1.12, 95% CI 0.60–2.10, P=0.712). The benefit of LT was less apparent in patients with small vessel disease and intracranial atherosclerosis than in those with extracranial atherosclerosis.
Conclusion
In contrast to the French TST, the outcomes in Korean patients were neutral. Although LT was more effective in preventing cardiovascular diseases, it was not so in stroke prevention, probably attributed to the differences in stroke subtypes. Further studies are needed to elucidate the efficacy of statins and appropriate LDL-C targets in Asian patients with stroke.
7.Digital Phenotyping of Rare Endocrine Diseases Across International Data Networks and the Effect of Granularity of Original Vocabulary
Seunghyun LEE ; Namki HONG ; Gyu Seop KIM ; Jing LI ; Xiaoyu LIN ; Sarah SEAGER ; Sungjae SHIN ; Kyoung Jin KIM ; Jae Hyun BAE ; Seng Chan YOU ; Yumie RHEE ; Sin Gon KIM
Yonsei Medical Journal 2025;66(3):187-194
Purpose:
Rare diseases occur in <50 per 100000 people and require lifelong management. However, essential epidemiological data on such diseases are lacking, and a consecutive monitoring system across time and regions remains to be established. Standardized digital phenotypes are required to leverage an international data network for research on rare endocrine diseases. We developed digital phenotypes for rare endocrine diseases using the observational medical outcome partnership common data model.
Materials and Methods:
Digital phenotypes of three rare endocrine diseases (medullary thyroid cancer, hypoparathyroidism, pheochromocytoma/paraganglioma) were validated across three databases that use different vocabularies: Severance Hospital’s electronic health record from South Korea; IQVIA’s United Kingdom (UK) database for general practitioners; and IQVIA’s United States (US) hospital database for general hospitals. We estimated the performance of different digital phenotyping methods based on International Classification of Diseases (ICD)-10 in the UK and the US or systematized nomenclature of medicine clinical terms (SNOMED CT) in Korea.
Results:
The positive predictive value of digital phenotyping was higher using SNOMED CT-based phenotyping than ICD-10-based phenotyping for all three diseases in Korea (e.g., pheochromocytoma/paraganglioma: ICD-10, 58%–62%; SNOMED CT, 89%). Estimated incidence rates by digital phenotyping were as follows: medullary thyroid cancer, 0.34–2.07 (Korea), 0.13–0.30 (US); hypoparathyroidism, 0.40–1.20 (Korea), 0.59–1.01 (US), 0.00–1.78 (UK); and pheochromocytoma/paraganglioma, 0.95–1.67 (Korea), 0.35–0.77 (US), 0.00–0.49 (UK).
Conclusion
Our findings demonstrate the feasibility of developing digital phenotyping of rare endocrine diseases and highlight the importance of implementing SNOMED CT in routine clinical practice to provide granularity for research.
8.Randomized Multicenter Study to Evaluate the Efficacy and Safety of Fexuprazan According to the Timing of Dosing in Patients With Erosive Esophagitis
Sang Pyo LEE ; In-Kyung SUNG ; Oh Young LEE ; Myung-Gyu CHOI ; Kyu Chan HUH ; Jae-Young JANG ; Hoon Jai CHUN ; Joong-Goo KWON ; Gwang Ha KIM ; Nayoung KIM ; Poong-Lyul RHEE ; Sang Gyun KIM ; Hwoon-Yong JUNG ; Joon Seong LEE ; Yong Chan LEE ; Hye-Kyung JUNG ; Jae Gyu KIM ; Sung Kook KIM ; Chong-il SOHN
Journal of Neurogastroenterology and Motility 2025;31(1):86-94
Background/Aims:
Fexuprazan, a novel potassium-competitive acid blocker, was developed for treating acid-related disorders. Pharmacokinetic and pharmacodynamic properties of fexuprazan, unlike those of proton pump inhibitors, are independent of food effect. This study aims to evaluate differences in efficacy and safety of fexuprazan in patients with erosive esophagitis (EE) according to the timing of dosing.
Methods:
In this multicenter, open-label noninferiority study, patients who had typical reflux symptoms with endoscopically confirmed EE were randomized 1:1 to receive fexuprazan 40 mg daily 30 minutes before or after meal. Treatment was completed after 2 weeks or 4 weeks when healing was endoscopically confirmed. The primary endpoint was the proportion of patients with healed EE confirmed by endoscopy up to week 4. Safety endpoints included treatment-emergent adverse events (TEAEs).
Results:
In the prior-to-meal group (n = 89) and after-meal group (n = 86), 4-week EE healing rates were 98.77% and 100.00% (difference, 0.01%; 95% CI, –0.01% to 0.04%) and 2-week EE healing rates were 95.77% and 97.14% (difference, 0.01%; 95% CI, –0.05% to 0.07%), respectively. TEAEs were 9.78% and 8.70% in the prior-to-meal group and the after-meal group, respectively.
Conclusions
Non-inferiority analysis revealed that taking fexuprazan after meal was non-inferior to taking fexuprazan before meals in patients with EE. The frequency of adverse events was similar between the 2 study groups. The drug is safe and effective for healing EE regardless of the timing of dosing.
9.Low-Density Lipoprotein Cholesterol Level, the Lower the Better? Analysis of Korean Patients in the Treat Stroke to Target Trial
Hanim KWON ; Jae-Chan RYU ; Jae-Kwan CHA ; Sang Min SUNG ; Tae-Jin SONG ; Kyung Bok LEE ; Eung-Gyu KIM ; Yong-Won KIM ; Ji Hoe HEO ; Man Seok PARK ; Kyusik KANG ; Byung-Chul LEE ; Keun-Sik HONG ; Oh Young BANG ; Jei KIM ; Jong S. KIM
Journal of Stroke 2025;27(2):228-236
Background:
and Purpose The Treat Stroke to Target (TST) was a randomized clinical trial involving French and Korean patients demonstrating that a lower low-density lipoprotein cholesterol (LDL-C, <70 mg/dL) target group (LT) experienced fewer cerebro-cardiovascular events than a higher target (90–110 mg/dL) group (HT). However, whether these results can be applied to Asian patients with different ischemic stroke subtypes remains unclear.
Methods:
Patients from 14 South Korean centers were analyzed separately. Patients with ischemic stroke or transient ischemic attack with evidence of atherosclerosis were randomized into LT and HT groups. The primary endpoint was a composite of ischemic stroke, myocardial infarction, coronary or cerebral revascularization, and cardiovascular death.
Results:
Among 712 enrolled patients, the mean LDL-C level was 71.0 mg/dL in 357 LT patients and 86.1 mg/dL in 355 HT patients. The primary endpoint occurred in 24 (6.7%) of LT and in 31 (8.7%) of HT group patients (adjusted hazard ratio [HR]=0.78; 95% confidence interval [CI]=0.45–1.33, P=0.353). Cardiovascular events alone occurred significantly less frequently in the LT than in the HT group (HR 0.26, 95% CI 0.09–0.80, P=0.019), whereas there were no significant differences in ischemic stroke events (HR 1.12, 95% CI 0.60–2.10, P=0.712). The benefit of LT was less apparent in patients with small vessel disease and intracranial atherosclerosis than in those with extracranial atherosclerosis.
Conclusion
In contrast to the French TST, the outcomes in Korean patients were neutral. Although LT was more effective in preventing cardiovascular diseases, it was not so in stroke prevention, probably attributed to the differences in stroke subtypes. Further studies are needed to elucidate the efficacy of statins and appropriate LDL-C targets in Asian patients with stroke.
10.Digital Phenotyping of Rare Endocrine Diseases Across International Data Networks and the Effect of Granularity of Original Vocabulary
Seunghyun LEE ; Namki HONG ; Gyu Seop KIM ; Jing LI ; Xiaoyu LIN ; Sarah SEAGER ; Sungjae SHIN ; Kyoung Jin KIM ; Jae Hyun BAE ; Seng Chan YOU ; Yumie RHEE ; Sin Gon KIM
Yonsei Medical Journal 2025;66(3):187-194
Purpose:
Rare diseases occur in <50 per 100000 people and require lifelong management. However, essential epidemiological data on such diseases are lacking, and a consecutive monitoring system across time and regions remains to be established. Standardized digital phenotypes are required to leverage an international data network for research on rare endocrine diseases. We developed digital phenotypes for rare endocrine diseases using the observational medical outcome partnership common data model.
Materials and Methods:
Digital phenotypes of three rare endocrine diseases (medullary thyroid cancer, hypoparathyroidism, pheochromocytoma/paraganglioma) were validated across three databases that use different vocabularies: Severance Hospital’s electronic health record from South Korea; IQVIA’s United Kingdom (UK) database for general practitioners; and IQVIA’s United States (US) hospital database for general hospitals. We estimated the performance of different digital phenotyping methods based on International Classification of Diseases (ICD)-10 in the UK and the US or systematized nomenclature of medicine clinical terms (SNOMED CT) in Korea.
Results:
The positive predictive value of digital phenotyping was higher using SNOMED CT-based phenotyping than ICD-10-based phenotyping for all three diseases in Korea (e.g., pheochromocytoma/paraganglioma: ICD-10, 58%–62%; SNOMED CT, 89%). Estimated incidence rates by digital phenotyping were as follows: medullary thyroid cancer, 0.34–2.07 (Korea), 0.13–0.30 (US); hypoparathyroidism, 0.40–1.20 (Korea), 0.59–1.01 (US), 0.00–1.78 (UK); and pheochromocytoma/paraganglioma, 0.95–1.67 (Korea), 0.35–0.77 (US), 0.00–0.49 (UK).
Conclusion
Our findings demonstrate the feasibility of developing digital phenotyping of rare endocrine diseases and highlight the importance of implementing SNOMED CT in routine clinical practice to provide granularity for research.

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