👤 Da-Eun Sung

Aging disrupts the neurovascular unit (NVU) and blood-brain barrier (BBB), elevates glial inflammatory tone, and compromises hippocampal memory. Environmental enrichment (EE)-a multimodal, lifestyle-based intervention-improves cognition, but its association with BBB/NVU and FNDC5/irisin-related signaling in aging remains incompletely understood. Aged male C57BL/6J mice (21 months old) were housed under EE or standard conditions for 11 weeks. Hippocampal-dependent spatial working memory was assessed using the radial eight-arm maze, and neuronal (NeuN), glial (Iba1, GFAP), and BBB/NVU markers (AQP4 endfoot polarity, occludin, ZO-1, PECAM-1, microvessel length/density) were quantified. FNDC5/irisin-related signaling was evaluated by measuring PGC-1α, FNDC5/irisin, IGF-1, BDNF, Show less

The brain-derived neurotrophic factor (BDNF) plays a crucial role in neuroprotection, and we have previously demonstrated BDNF-mediated neuroprotective effects in mesenchymal stromal cells (MSCs). The present study aimed to investigate whether BDNF-overexpressing MSCs enhance the therapeutic efficacy of naïve MSCs in a preclinical model of severe neonatal intraventricular hemorrhage (IVH). We exposed primary rat neuronal cells to 40 U of thrombin overnight Show less

Angiopoietin-like 4 (Angptl4) is a secreted glycoprotein involved in the regulation of various homeostatic and disease processes. In the intestine, prior studies have suggested protective roles for Angptl4 in inflammation using Angptl4 knockout mouse models; however, phenotypic variability-such as perinatal lethality and intestinal inflammation accompanied by lymphatic defects in only a subset of animals-has complicated the interpretation of its role in intestinal pathogenesis. In this study, the impact of Angptl4 deficiency was examined using a subset of Angptl4 knockout mice that survive postnatally without overt abnormalities. It was found that loss of Angptl4 confers protection against colitis and colitis-associated colorectal tumorigenesis. These protective effects were associated with the alternative activation of anti-inflammatory M2-like macrophages. Similarly, in a genetic model of intestinal tumorigenesis, Angptl4 deficiency resulted in reduced tumor burden and attenuated inflammation, accompanied by increased M2-like macrophages. Analysis of human colorectal cancer data sets further revealed that low ANGPTL4 expression is associated with improved survival outcomes as well as reduced expression of inflammation-related marker genes. Collectively, the findings uncover a previously unrecognized protective effect of Angptl4 deficiency against intestinal pathogenesis via anti-inflammatory mechanisms, suggesting Angptl4 as a potential therapeutic target and prognostic biomarker for colorectal cancer and inflammatory bowel disease. Show less

Lipoprotein(a) [Lp(a)] is a genetically determined cardiovascular risk factor. Although generally considered stable, data on intra-individual reclassification of Lp(a) categories over time compared with conventional lipid markers remain limited, particularly in East Asian populations. We conducted a retrospective cohort study including 230,018 Korean adults (mean age, 38·5 years; 51·4 % male) who underwent routine health examinations with at least two Lp(a) measurements between July 1, 2015, and December 30, 2022. Individuals with a history of coronary artery disease or those receiving lipid-lowering therapy were excluded. The primary outcomes were intraclass correlation coefficients (ICCs), reclassification rates across predefined Lp(a) categories (<30, 30-50, 50-100, and ≥100 mg/dL), and comparisons with traditional lipid parameters. Lp(a) demonstrated excellent reproducibility (ICC ≥0·99) and greater long-term stability than LDL-C, ApoB, and triglycerides. Among participants with baseline Lp(a) levels <30 mg/dL or ≥100 mg/dL, 93 % and 91 % remained in the same category at follow-up, respectively. However, among those with baseline Lp(a) levels of 30-50 mg/dL, 35 % transitioned to higher-risk categories, as did 19 % of those with levels of 50-100 mg/dL. By comparison, 28 % of individuals with LDL-C ≥160 mg/dL and 22 % with triglycerides ≥200 mg/dL moved to lower categories during follow-up. Lp(a) demonstrates greater stability than conventional lipid markers. While a single measurement may suffice for clearly low (<30 mg/dL) or high (≥100 mg/dL) Lp(a) levels, periodic reassessment may be clinically warranted for individuals in intermediate Lp(a) levels (30-100 mg/dL). Show less

Lipoprotein(a) [Lp(a)] is a genetically determined, independent risk factor for atherosclerotic cardiovascular disease. However, its role in coronary artery calcification (CAC) remains unclear. We aimed to determine whether Lp(a) levels are associated with the incidence and progression of CAC. We conducted a longitudinal cohort study (2015-22) of 41 929 adults (aged ≥30 years) who underwent baseline Lp(a) measurement and CAC assessment via multi-detector computed tomography. Participants were stratified into those with baseline CAC = 0 (n = 32 338) and CAC > 0 (n = 9591). Outcomes were analysed according to Lp(a) quintiles and clinically relevant categories (<30, 30-50, 50-100, ≥ 100 mg/dL). Cox proportional hazards models estimated hazard ratios (HRs) for incident CAC (CAC > 0) among those with CAC = 0 (median follow-up, 4.04 years). Linear mixed-effects models evaluated CAC progression among those with CAC > 0 (median follow-up, 3.78 years). All models were adjusted for cardiovascular risk factors. Among participants with CAC = 0 (mean age, 40.94 ± 5.81 years; 85.69% men), neither Lp(a) quintiles nor clinical categories were significantly associated with incident CAC [HR for highest vs. second quintile: 0.998 (95% confidence interval, CI, 0.90-1.10); HR for ≥100 vs. <30 mg/dL: 0.83 (95% CI, 0.57-1.23)]. Among those with CAC > 0 (mean age, 45.99 ± 7.20 years; 94.90% men), CAC progression did not differ materially across Lp(a) quintiles or clinical thresholds. Elevated Lp(a) levels were not associated with new-onset CAC or progression of existing CAC in this large longitudinal cohort. Show less

Multidomain lifestyle interventions have shown effectiveness in preventing dementia, but identifying high-risk groups most likely to benefit remains unclear. We re-evaluated the SUPERBRAIN-MEET multidomain intervention study in mild cognitive impairment (MCI) patients, incorporating polygenic risk scores (PRS) for Alzheimer's disease and APOE ε4 status using Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) total index as the primary outcome. Both intervention and control groups showed cognitive improvement over 24 weeks, with greater gains in the intervention arm. Relative intervention efficacy (RIE) increased with higher genetic risk, being most pronounced among APOE ε4 carriers and individuals with high PRS. When both factors were considered jointly, APOE ε4 carriers with high PRS exhibited the largest RIE (β = 7.54, SE = 2.59, p = 0.005), driven by markedly greater improvement in the intervention group. The secondary outcomes did not show as consistent results as RBANS total index. These findings suggest that MCI individuals who are APOE ε4 carriers with high PRS may benefit most from multidomain interventions. These results support the complementary use of PRS and APOE status for identifying high-risk subgroups most likely to benefit from multidomain interventions. ClinicalTrials.gov identifier: NCT05023057. Registered on 26 August 2021. Show less

Glucose can activate the carbohydrate response element binding protein (ChREBP) transcription factor to control gene expressions in the metabolic pathways. The way of ChREBP involvement in human prostate cancer development remains undetermined. This study examined the interactions between prostate fibroblasts and cancer cells under the influences of ChREBP. Results showed that high glucose (30 mM) increased the phosphorylation of AKT at S473 and AMP-activated protein kinase (AMPK) at S485 in human prostate fibroblast (HPrF) cells and prostate cancer PC-3 cells. High glucose enhanced the expression of ChREBP, which increased the expressions of fibronectin, alpha-smooth muscle actin (α-SMA), and WNT1 inducible signaling pathway protein 1 (WISP1), magnifying the cell growth and contraction in HPrF cells in vitro. The cell proliferation, invasion, and tumor growth in prostate cancer PC-3 cells were enhanced by inducing the expressions of ChREBP, mucosa-associated lymphoid tissue 1 (MALT1), and epithelial-mesenchymal transition markers with high glucose treatment. Moreover, ectopic ChREBP overexpression induced NF-κB signaling activities via upregulating MALT1 expression in PC-3 cells. Our findings illustrated that ChREBP is an oncogene in the human prostate. High glucose condition induces a glucose/ChREBP/MALT1/NF-κB axis which links the glucose metabolism to the NF-κB activation in prostate cancer cells, and a glucose/ChREBP/WISP1 axis mediating autocrine and paracrine signaling between fibroblasts and cancer cells to promote cell migration, contraction, growth, and invasion of the human prostate. Show less

The tumor microenvironment (TME) plays a pivotal role in cancer progression, with cancer-associated fibroblasts (CAFs) significantly influencing tumor behavior. Especially, elevated COX2 expressing fibroblasts within the TME, notably in collagen-dense tumors like breast cancer, has been recently emphasized in the literature. However, the specific effect of COX2-expressing CAFs (COX2 We induced COX2 Our in vitro findings demonstrate that COX2 This study advances our understanding of the potential mechanisms by which COX2 Show less

Phytosphingosine (PHS) is a major component of the skin barrier and a multifunctional physiologically active substance. This study  aimed to investigate the types of cytokines regulated by PHS, their anti-skin inflammatory effects, and their anti-inflammatory mechanisms. RAW264.7 cells stimulated with Lipopolysaccharides (LPS) were treated with PHS to measure inflammatory factors such as nitric oxide (NO) and prostaglandin E2 (PGE2), and gene expressions of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX2) were confirmed by q-PCR. Cytokines regulated by PHS against LPS-induced inflammation were found through cytokine array, and each factor was reconfirmed through ELISA. Western blot was performed to confirm anti-inflammatory mechanism of Iκbα and MAPK. To confirm anti-skin inflammatory efficacy, HaCaT cells stimulated with TNF-α/IFN-γ were treated with PHS, and TARC, IL-6, and IL-8 were detected by ELISA. PHS suppressed the gene expression of iNOS and COX2, which were increased by LPS, and suppressed NO and PGE2 production. Through cytokine array, it was confirmed that IL-6, IL-10, IL-27 p28/IL-30, IP-10, I-TAC, MCP-5, and TIMP-1 increased by LPS were decreased by PHS. PHS inhibited NF-κB signaling by inhibiting LPS-induced NF-κB nuclear migration and p-Iκbα-mediated Iκbα degradation, and inhibited p38, ERK, and JNK signaling pathways. PHS reduced the production of TARC, IL-6, and IL-8 increased by TNF-α/IFN-γ. These results indicate PHS has anti-inflammatory effects via the suppression of inflammatory factors and pro-inflammatory cytokines through the NF-κB and MAPK pathways. Moreover, these results may explain beneficial effects of PHS in the treatment of skin inflammatory conditions induced by TNF-α/IFN-γ. Show less

Although stem cells are a promising avenue for harnessing the potential of adipose tissue, conventional two-dimensional (2D) culture methods have limitations. This study explored the use of three-dimensional (3D) cultures to preserve the regenerative potential of adipose-derived stem cells (ADSCs) and investigated their cellular properties. Flow cytometric analysis revealed significant variations in surface marker expressions between the two culture conditions. While 2D cultures showed robust surface marker expressions, 3D cultures exhibited reduced levels of CD44, CD90.2, and CD105. Adipogenic differentiation in 3D organotypic ADSCs faced challenges, with decreased organoid size and limited activation of adipogenesis-related genes. Key adipocyte markers, such as lipoprotein lipase (LPL) and adipoQ, were undetectable in 3D-cultured ADSCs, unlike positive controls in 2D-cultured mesenchymal stem cells (MSCs). Surprisingly, 3D-cultured ADSCs underwent mesenchymal-epithelial transition (MET), evidenced by increased E-cadherin and EpCAM expression and decreased mesenchymal markers. This study highlights successful ADSC organoid formation, notable MSC phenotype changes in 3D culture, adipogenic differentiation challenges, and a distinctive shift toward an epithelial-like state. These findings offer insights into the potential applications of 3D-cultured ADSCs in regenerative medicine, emphasizing the need for further exploration of underlying molecular mechanisms. Show less

GPR40 is found primarily in pancreatic β cells, and is well known to regulate insulin secretion. Despite numerous studies on GPR40, the role and functions of GPR40 related to hair growth are not yet known. The current study investigated hair growth promoting effect of the GPR40 agonists and its mechanism of action using various bio-informatics tools, in vitro and animal experiments. GPR40 may affect the hair cycle, according to clustering and Gene Set Enrichment Analysis (GSEA). Hair growth effect of GPR40 was validated by telogen-to-anagen transition and vibrissae organ culture in the mouse. GPR40 was predominantly expressed in the outer root sheath (ORS) in anagen stage, suggesting that ORS cell is the target of GPR40 agonists. To investigate the mechanism of action for GPR40 agonists' hair growth effect, Gene Ontology (GO) enrichment analysis was performed and it revealed that GPR40 agonists were associated with angiogenesis. ANGPTL4, known for promoting angiogenesis, was highly up-regulated after GPR40 agonists treatment in the hORS cells, and also increased the proliferation and migration. Furthermore, GPR40 agonists promoted hair growth by inducing angiogenesis via ANGPTL4 in the animal experiment. GPR40 agonists activated MAPK and peroxisome proliferator-activated receptors (PPARγ) pathway in hORS cells, while the inhibition of MAPK pathway attenuated ANGPTL4 expression. Finally, GPR40 agonists increased hair growth via autocrine effects in the ORS cells, and induced angiogenesis through paracrine effects by upregulating ANGPTL4 via p38 and PPARγ pathways. As a result, GPR40 agonists have potential as a therapeutic drug for hair loss treatment. Show less

Mutations or triplication of the alpha synuclein (ASYN) gene contribute to synucleinopathies including Parkinson's disease (PD), Dementia with Lewy bodies (DLB) and multiple system atrophy (MSA). Recent evidence suggests that ASYN also plays an important role in amyloid-induced neurotoxicity, although the mechanism(s) remains unknown. One hypothesis is that accumulation of ASYN alters endolysosomal pathways to impact axonal trafficking and processing of the amyloid precursor protein (APP). To define an axonal function for ASYN, we used a transgenic mouse model of synucleinopathy that expresses a GFP-human ASYN (GFP-hASYN) transgene and an ASYN knockout (ASYN Show less

Lung adenocarcinoma is the most common type of lung cancer. Known risk variants explain only a small fraction of lung adenocarcinoma heritability. Here, we conducted a two-stage genome-wide association study of lung adenocarcinoma of East Asian ancestry (21,658 cases and 150,676 controls; 54.5% never-smokers) and identified 12 novel susceptibility variants, bringing the total number to 28 at 25 independent loci. Transcriptome-wide association analyses together with colocalization studies using a Taiwanese lung expression quantitative trait loci dataset (n = 115) identified novel candidate genes, including FADS1 at 11q12 and ELF5 at 11p13. In a multi-ancestry meta-analysis of East Asian and European studies, four loci were identified at 2p11, 4q32, 16q23, and 18q12. At the same time, most of our findings in East Asian populations showed no evidence of association in European populations. In our studies drawn from East Asian populations, a polygenic risk score based on the 25 loci had a stronger association in never-smokers vs. individuals with a history of smoking (P Show less

Acute myeloid leukemia (AML) with megakaryocytic differentiation (AMkL) is a rare subtype of AML more common in children. Recent literature has identified multiple fusions associated with this type of leukemia. Morphology, cytogenetics, and genomic sequencing were assessed in patients from Children's Oncology Group trials AAML0531 and AAML1031 with central-pathology review confirmed non-Down syndrome AMkL. The 5-year event-free survival (EFS), overall survival (OS), and RR were evaluated in these AMkL subcategories. A total of 107 cases of AMkL (5.5%) were included. Distinct fusions were identified in the majority: RBM15::MRTFA (20%), CBFA2T3::GLIS2 (16%), NUP98 (10%), KMT2A (7%), TEC::MLLT10 (2%), MECOM (1%), and FUS::ERG (1%); many of the remaining cases were classified as AMkL with (other) myelodysplasia-related changes (MRC). Very few cases had AML-associated somatic mutations. Cases with CBFA2T3::GLIS2 were enriched in trisomy 3 (p = .015) and the RAM phenotype, with associated high CD56 expression (p < .001). Cases with NUP98 fusions were enriched in trisomy 6 (p < .001), monosomy 13/del(13q) (p < .001), trisomy 21 (p = .026), and/or complex karyotypes (p = .026). While different 5-year EFS and OS were observed in AMkL in each trial, in general, those with CBFA2T3::GLIS2 or KMT2A rearrangements had worse outcomes compared to other AMkL, while those with RBM15::MRTFA or classified as AMkl-MRC fared better. AMkL with NUP98 fusions also had poor outcomes in the AAML1031 trial. Given the differences in outcomes, AMkL classification by fusions, cytogenetics, and morphology may be warranted to help in risk stratification and therapeutic options. Show less

Toluene diisocyanate (TDI), a major intermediate agent used in the manufacturing industry, causes respiratory symptoms when exposed to the human body. In this study, we aimed to determine the molecular mechanism of TDI toxicity. To investigate the impact of TDI exposure on global gene expression, we performed transcriptomic analysis of human bronchial epithelial cells (BEAS-2B) after TDI treatment. Differentially expressed genes (DEGs) were sorted and used for clustering and network analysis. Among DEGs, dual-specificity phosphatase 6 (DUSP6) was one of the genes significantly changed by TDI exposure. To verify the expression level of DUSP6 and its effect on lung cells, the mRNA and protein levels of DUSP6 were analyzed. Our results showed that DUSP6 was dose-dependently upregulated by TDI treatment. Thereby, the phosphorylation of ERK1/2, one of the direct inhibitory targets of DUSP6, was decreased. TDI exposure also increased the mRNA level of p53 along with its protein and activity which trans-activates DUSP6. Since TRPA1 is known as a signal integrator activated by TDI, we analyzed the relevance of TRPA1 receptor in DUSP6 regulation. Our data revealed that up-regulation of DUSP6 mediated by TDI was blocked by a specific antagonist against TRPA1. TDI exposure attenuated the apoptotic response, which suggests that it promotes the survival of cancerous cells. In conclusion, our results suggest that TDI induces DUSP6 and p53, but attenuates ERK1/2 activity through TRPA1 receptor activation, leading to cytotoxicity. Show less

Glycosaminoglycans are ubiquitously expressed polysaccharides that are attached to proteoglycans. Here, we showed that ablation of the heparan sulfate (HS) polymerase Ext1 in retinal progenitor cells did not affect initial progression of retinal angiogenesis, but it disrupted the pruning of blood vessels and establishment of arterioles and venules. In the absence of retinal HS, blood vessels were also vulnerable to high oxygen tension in early postnatal stages, which could be rescued by exogenous vascular endothelial growth factor (VEGF), consistent with the role of retinal HS in the fine-tuning of VEGF signaling. Furthermore, we observed that the retinal inner limiting membrane (ILM) was disrupted by deletion of Ext1 in a timing-specific manner, suggesting that retinal HS is required for the assembly but not the maintenance of the basement membrane. Lastly, we showed that further deletion of C4st1, a chondroitin sulfate (CS) sulfation enzyme, did not affect the assembly of the ILM but, when combined with Ext1 deletion, it aggravated the retinal permeability by disrupting the retinal glycocalyx. These results demonstrate an important role of CS and HS in establishing the barrier function of the extracellular matrix. Show less

Patients with liver cirrhosis (LC) have low levels of branched-chain amino acids (BCAAs). There is accumulating evidence that BCAAs have anti- fibrotic effects in cirrhosis. This study is aimed to evaluate the effect of BCAAs on the function and phenotype of activated hepatic stellate cells (HSCs). LX-2, an immortalized human stellate cell line, was used in in vitro experiments. LX-2 cells were exposed to transforming growth factor β1 (TGF-β1) and BCAAs or to valine, leucine, and isoleucine, which are components of BCAAs. Activation of the TGF-β signaling pathway in LX-2 cells was observed using real-time quantitative polymerase chain reaction and Western blotting. The increased expression of snail family transcriptional repressor 1 (SNAI1) was observed in LX-2 cells activated by TGF-β1. After BCAA treatment, its expression was significantly decreased at the mRNA level. The increased expression of Col1α1 and TIMP2 at the mRNA level and alpha smooth muscle actin at the protein level in activated LX-2 cells decreased after BCAA treatment. Among the BCAA components, leucine and valine significantly abrogated TGF-β-induced activation of LX-2 cells. BCAA treatment led to the decreased phosphorylation of Smad2 and p38 proteins, which are markers for Smad and Smad-independent p38 mitogen-activated protein kinase signaling pathways, respectively. BCAA treatment can improve hepatic fibrosis by directly affecting the activated state of hepatic stellate cells through inhibition of the TGF-β signaling pathway. Among BCAA components, leucine and valine mainly abrogated TGF-β-induced activation of HSCs. Our results suggest that BCAA may be used to attenuate the progression of liver fibrosis. Show less

Biomarkers in exposure assessment are defined as the quantifiable targets that indicate the exposure to hazardous chemicals and their resulting health effect. In this study, we aimed to identify, validate, and characterize the mRNA biomarker that can detect the exposure of sodium cyanide. To identify reliable biomarkers for sodium cyanide exposure, critical criteria were defined for candidate selection: (1) the expression level of mRNA significantly changes in response to sodium thiocyanate treatment in transcriptomics results (fold change > 2.0 or <0.50, adjusted Show less

Little is known about the mutational landscape of advanced hepatocellular carcinoma (HCC), and predictive biomarkers of response to systemic therapies are lacking. We aimed to describe the mutational landscape of advanced HCC and to identify predictors of primary resistance to systemic therapies using circulating tumor DNA (ctDNA). We prospectively enrolled 121 patients between October 2015 and January 2019. We performed targeted ultra-deep sequencing of 25 genes and Digital Droplet PCR of TERT promoter, including sequential samples throughout treatment. Primary endpoint was progression-free survival (PFS) stratified by mutation profiles in ctDNA. Secondary endpoints were overall survival and objective response rate. The most frequent mutations in ctDNA of advanced HCC were TERT promoter (51%), TP53 (32%), CTNNB1 (17%), PTEN (8%), AXIN1, ARID2, KMT2D, and TSC2 (each 6%). TP53 and CTNNB1 mutations were mutually exclusive. Patients with mutations in the PI3K/MTOR pathway had significantly shorter PFS than those without these mutations after tyrosine kinase inhibitors (2.1 vs 3.7 months, p < 0.001), but not after immune checkpoint inhibition (CPI). WNT pathway mutations were not associated with PFS, overall survival, or objective response after CPI. Serial profiling of ctDNA in a subset correlated with treatment response. Mutation profiling of ctDNA in advanced HCC shows similar mutation frequencies for known HCC drivers compared to early stages and identifies predictive biomarkers of response to systemic therapies. Show less

Dyslipidemia is a well-established risk factor for CVD. Studies suggest that similar fat accumulation in a given population might result in different levels of dyslipidemia risk among individuals; for example, despite similar or leaner body composition compared with Caucasians, Asians of Korean descent experience a higher prevalence of dyslipidemia. These variations imply a possible role of gene-obesity interactions on lipid profiles. Genome-wide association studies have identified more than 500 loci regulating plasma lipids, but the interaction structure between genes and obesity traits remains unclear. We hypothesized that some loci modify the effects of obesity on dyslipidemia risk and analyzed extensive gene-environment interactions (G×Es) at genome-wide levels to search for replicated gene-obesity interactive SNPs. In four Korean cohorts (n = 18,025), we identified and replicated 20 gene-obesity interactions, including novel variants ( Show less

Metabolic syndrome (MetS) arises from complex interactions between host genetic and environmental factors. Although it is now widely accepted that the gut microbiota plays a crucial role in host metabolism, current knowledge on the effect of host genetics on specific gut microbes related to MetS status remains limited. Here, we investigated the links among host genetic factors, gut microbiota and MetS in humans. We characterised the gut microbial community composition of 655 monozygotic (n=306) and dizygotic (n=74) twins and their families (n=275), of which approximately 18% (121 individuals) had MetS. We evaluated the association of MetS status with the gut microbiota and estimated the heritability of each taxon. For the MetS-related and heritable taxa, we further investigated their associations with the apolipoprotein A-V gene ( Individuals with MetS had a lower gut microbiota diversity than healthy individuals. The abundances of several taxa were associated with MetS status; Our results suggest that an altered microbiota composition mediated by a specific host genotype can contribute to the development of MetS. Show less

Gastric cancer is not a single disease, and its subtype classification is still evolving. Next-generation sequencing studies have identified novel genetic drivers of gastric cancer, but their use as molecular classifiers or prognostic markers of disease outcome has yet to be established. In this study, we integrated somatic mutational profiles and clinicopathologic information from 544 gastric cancer patients from previous genomic studies to identify significantly mutated genes (SMG) with prognostic relevance. Gastric cancer patients were classified into regular (86.8%) and hypermutated (13.2%) subtypes based on mutation burden. Notably, TpCpW mutations occurred significantly more frequently in regular, but not hypermutated, gastric cancers, where they were associated with APOBEC expression. In the former group, six previously unreported (XIRP2, NBEA, COL14A1, CNBD1, ITGAV, and AKAP6) and 12 recurrent mutated genes exhibited high mutation prevalence (≥3.0%) and an unexpectedly higher incidence of nonsynonymous mutations. We also identified two molecular subtypes of regular-mutated gastric cancer that were associated with distinct prognostic outcomes, independently of disease staging, as confirmed in a distinct patient cohort by targeted capture sequencing. Finally, in diffuse-type gastric cancer, CDH1 mutation was found to be associated with shortened patient survival, independently of disease staging. Overall, our work identified previously unreported SMGs and a mutation signature predictive of patient survival in newly classified subtypes of gastric cancer, offering opportunities to stratify patients into optimal treatment plans based on molecular subtyping. Cancer Res; 76(7); 1724-32. ©2016 AACR. Show less

Obesity is known to increase the risk of colorectal cancer. However, mechanisms underlying the pathogenesis of obesity-induced colorectal cancer are not completely understood. The purposes of this study were to identify differentially expressed genes in the colon of mice with diet-induced obesity and to select candidate genes as early markers of obesity-associated abnormal cell growth in the colon. C57BL/6N mice were fed normal diet (11% fat energy) or high-fat diet (40% fat energy) and were euthanized at different time points. Genome-wide expression profiles of the colon were determined at 2, 4, 8, and 12 weeks. Cluster analysis was performed using expression data of genes showing log High-fat diet-fed mice showed significant increase in body weight and total visceral fat weight over 12 weeks. Time-course microarray analysis showed that 50, 47, 36, and 411 genes were differentially expressed at 2, 4, 8, and 12 weeks, respectively. Ten cluster profiles representing distinguishable patterns of genes differentially expressed over time were determined. Cluster 4, which consisted of genes showing the most significant alterations in expression in response to high-fat diet over 12 weeks, included Our data indicate that Show less

Genetic studies of plasma TG levels have identified associations with multiple candidate loci on chromosome11q23.3, which harbors a number of genes, including BUD13, ZNF259, and APOA5-A4-C3-A1. This study aimed to examine whether these multiple candidate genes on the 11q23.3 regions exert independent effects on TG levels or whether their effects are confounded by linkage disequilibrium (LD). We performed a genome-wide association study and consequent fine-mapping analyses on TG levels in two Korean population-based cohorts: the Korea Association Resource study (n = 8,223) and the Healthy Twin study (n = 1,735). A total of 301 loci reached genome-wide significance level in pooled analysis, including 10 SNPs with weak LD (r(2) < 0.06) clustered on 11q23.3: ApoA5 (rs651821, rs2075291); ZNF259 (rs964184, rs603446); BUD13 (rs11216126); Apoa4 (rs7396851); SIK3 (rs12292858); PCSK7 (rs199890178); PAFAH1B2 (rs12420127), and SIDT2 (rs2269399). When the inter-dependence between alleles was examined using conditional models, five loci on BUD13, ZNF259, and ApoA5 showed possible independent associations. A haplotype analysis using five SNPs revealed both hyper- and hypotriglyceridemic haplotypes, which are relatively common in Koreans (haplotype frequency 0.08-0.22). Our findings suggest the presence of multiple functional loci on 11q23.3, which might exert their effects on plasma TG level independently or through complex interactions between functional loci. Show less

Metabolic syndrome has closely linked to the development of human hepatocellular carcinoma (HCC). By using the hepatitis B virus (HBV) X (HBx) transgenic mouse model, we studied the dynamic evolution of serum and liver profiles of lipids and global cDNA expression at different stages of HBx tumorigenesis. We observed that the lipid (triglycerides, cholesterol, and fatty acids) profiles revealed a biphasic response pattern during the progression of HBx tumorigenesis: a small peak at early phase and a large peak or terminal switch at the tumor phase. By analyzing cDNA microarray data, the early peak correlated to the oxidative stress and pro-inflammatory response, which then resolved at the middle phase and were followed by the terminal metabolic switch in the tumor tissues. Five lipid metabolism-related genes, the arachidonate 5-lipoxygenase, lipoprotein lipase, fatty acid binding protein 4, 1-acylglycerol-3-phosphate O-acyltransferase 9, and apolipoprotein A-IV were identified to be significantly activated in HBx transgenic HCCs and further validated in human HBV-related HCCs. Inhibition of these lipid genes could reverse the effect of HBx on lipid biosynthesis and suppress HBx-induced cell proliferation in vitro. Our results support the concept that metabolic syndrome plays an important role in HBV tumorigenesis. The dysregulation of lipid metabolic genes may predict the disease progression to HCC in chronic hepatitis B patients. Show less

To identify loci associated with abdominal fat and replicate prior findings, we performed genome-wide association (GWA) studies of abdominal fat traits: subcutaneous adipose tissue (SAT); visceral adipose tissue (VAT); total adipose tissue (TAT) and visceral to subcutaneous adipose tissue ratio (VSR). Sex-combined and sex-stratified analyses were performed on each trait with (TRAIT-BMI) or without (TRAIT) adjustment for body mass index (BMI), and cohort-specific results were combined via a fixed effects meta-analysis. A total of 2513 subjects of European descent were available for the discovery phase. For replication, 2171 European Americans and 772 African Americans were available. A total of 52 single-nucleotide polymorphisms (SNPs) encompassing 7 loci showed suggestive evidence of association (P<1.0 × 10(-6)) with abdominal fat in the sex-combined analyses. The strongest evidence was found on chromosome 7p14.3 between a SNP near BBS9 gene and VAT (rs12374818; P=1.10 × 10(-7)), an association that was replicated (P=0.02). For the BMI-adjusted trait, the strongest evidence of association was found between a SNP near CYCSP30 and VAT-BMI (rs10506943; P=2.42 × 10(-7)). Our sex-specific analyses identified one genome-wide significant (P<5.0 × 10(-8)) locus for SAT in women with 11 SNPs encompassing the MLLT10, DNAJC1 and EBLN1 genes on chromosome 10p12.31 (P=3.97 × 10(-8) to 1.13 × 10(-8)). The THNSL2 gene previously associated with VAT in women was also replicated (P=0.006). The six gene/loci showing the strongest evidence of association with VAT or VAT-BMI were interrogated for their functional links with obesity and inflammation using the Biograph knowledge-mining software. Genes showing the closest functional links with obesity and inflammation were ADCY8 and KCNK9, respectively. Our results provide evidence for new loci influencing abdominal visceral (BBS9, ADCY8, KCNK9) and subcutaneous (MLLT10/DNAJC1/EBLN1) fat, and confirmed a locus (THNSL2) previously reported to be associated with abdominal fat in women. Show less

Cardiovascular diseases are among the most significant health problems in the United States. Blood pressure (BP) variability has a genetic component, and most of the genetic variance remains to be identified. One promising strategy for gene discovery is genome-wide analysis of interactions between single nucleotide polymorphisms (SNPs) and environmental factors related to cardiovascular diseases. We investigated SNP-smoking interaction effects on BP in genome-wide data in 6,889 participants from the Framingham Heart Study. We performed the standard 1 degree of freedom (df) test of the interaction effect and the joint 2 df test of main and interaction effects. Three smoking measures were used: cigarettes per day (CPD), pack years of smoking, and smoking status. We identified 7 significant and 21 suggestive BP loci. Identified through the joint 2 df test, significant SBP loci include: rs12149862 (P = 3.65×10(-9)) in CYB5B, rs2268365 (P = 4.85×10(-8)) in LRP2, rs133980 (P = 1.71×10(-8) with CPD and P = 1.07×10(-8) with pack-years) near MN1, and rs12634933 (P = 4.05×10(-8)) in MECOM. Through 1 df interaction analysis, 1 suggestive SBP locus at SNP rs8010717 near NRXN3 was identified using all 3 smoking measures (P = 3.27×10(-7) with CPD, P = 1.03×10(-7) with pack-years, and P = 1.19×10(-7) with smoking status). Several of these BP loci are biologically plausible, providing physiological connection to BP regulation. Our study demonstrates that SNP-smoking interactions can enhance gene discovery and provide insight into novel pathways and mechanisms regulating BP. Show less

Hepatic resection is the most curative treatment option for early-stage hepatocellular carcinoma, but is associated with a high recurrence rate, which exceeds 50% at 5 years after surgery. Understanding the genetic basis of hepatocellular carcinoma at surgically curable stages may enable the identification of new molecular biomarkers that accurately identify patients in need of additional early therapeutic interventions. Whole exome sequencing and copy number analysis was performed on 231 hepatocellular carcinomas (72% with hepatitis B viral infection) that were classified as early-stage hepatocellular carcinomas, candidates for surgical resection. Recurrent mutations were validated by Sanger sequencing. Unsupervised genomic analyses identified an association between specific genetic aberrations and postoperative clinical outcomes. Recurrent somatic mutations were identified in nine genes, including TP53, CTNNB1, AXIN1, RPS6KA3, and RB1. Recurrent homozygous deletions in FAM123A, RB1, and CDKN2A, and high-copy amplifications in MYC, RSPO2, CCND1, and FGF19 were detected. Pathway analyses of these genes revealed aberrations in the p53, Wnt, PIK3/Ras, cell cycle, and chromatin remodeling pathways. RB1 mutations were significantly associated with cancer-specific and recurrence-free survival after resection (multivariate P = 0.038 and P = 0.012, respectively). FGF19 amplifications, known to activate Wnt signaling, were mutually exclusive with CTNNB1 and AXIN1 mutations, and significantly associated with cirrhosis (P = 0.017). RB1 mutations can be used as a prognostic molecular biomarker for resectable hepatocellular carcinoma. Further study is required to investigate the potential role of FGF19 amplification in driving hepatocarcinogenesis in patients with liver cirrhosis and to investigate the potential of anti-FGF19 treatment in these patients. Show less

Forced vital capacity (FVC), a spirometric measure of pulmonary function, reflects lung volume and is used to diagnose and monitor lung diseases. We performed genome-wide association study meta-analysis of FVC in 52,253 individuals from 26 studies and followed up the top associations in 32,917 additional individuals of European ancestry. We found six new regions associated at genome-wide significance (P < 5 × 10(-8)) with FVC in or near EFEMP1, BMP6, MIR129-2-HSD17B12, PRDM11, WWOX and KCNJ2. Two loci previously associated with spirometric measures (GSTCD and PTCH1) were related to FVC. Newly implicated regions were followed up in samples from African-American, Korean, Chinese and Hispanic individuals. We detected transcripts for all six newly implicated genes in human lung tissue. The new loci may inform mechanisms involved in lung development and the pathogenesis of restrictive lung disease. Show less

Collaborative regulation of liver X receptor (LXR) and sterol regulatory element binding protein (SREBP)-1 are main determinants in hepatic steatosis, as shown in both animal models and human patients. Recent studies indicate that selective intervention of overly functional LXRα in the liver shows promise in treatment of fatty liver disease. In the present study, we evaluated the effects of meso-dihydroguaiaretic acid (MDGA) on LXRα activation and its ability to attenuate fatty liver in mice. MDGA inhibited activation of the LXRα ligand-binding domain by competitively binding to the pocket for agonist T0901317 and decreased the luciferase activity in LXRE-tk-Luc-transfected cells. MDGA significantly attenuated hepatic neutral lipid accumulation in T0901317- and high fat diet (HFD)-induced fatty liver. The effect of MDGA was so potent that treatment with 1mg/kg for 2 weeks completely reversed the lipid accumulation induced by HFD feeding. MDGA reduced the expression of LXRα co-activator protein RIP140 and LXRα target gene products associated with lipogenesis in HFD-fed mice. These results demonstrate that MDGA has the potential to attenuate nonalcoholic steatosis mediated by selective inhibition of LXRα in the liver in mice. Show less