👤 SeokMin Yun

Exercise enhances learning and memory, not only through improved cardiometabolic but also through body-brain interactions mediated by secreted factors. Given the prominent role of skeletal muscle during exercise, muscle-derived factors, myokines, are believed to mediate the exercise-induced cognitive enhancements. Here, we demonstrate that intramuscular Serpina1e is upregulated following exercise in male mice. Systemic delivery of recombinant Serpina1e or intramuscular overexpression of Serpina1e reproduces exercise-induced memory enhancements in sedentary male mice. Conversely, muscle-specific depletion of Serpina1e abolishes hippocampal memory enhancement, indicating a requirement of muscle-derived Serpina1e for these cognitive benefits. Mechanistically, elevated plasma Serpina1e stimulates neurogenesis, brain-derived neurotrophic factor (BDNF) expression, and neurite growth in the hippocampus by crossing the blood-cerebrospinal fluid (CSF) and blood-brain barrier. Our findings identify Serpina1e as a key mediator of skeletal muscle-brain interaction that enables the beneficial effects of exercise on cognitive function. Show less

The proteasome is a major intracellular protease complex, but the significance of circulating proteasome activity in Alzheimer’s disease (AD) is not well established. Because APOE ε4 is the strongest genetic risk factor for AD, we examined whether plasma proteasome activity is associated with AD-related pathology, neurodegeneration, and cognitive decline, focusing on APOE ε4 carriers. In this observational study, participants were classified as cognitively normal (CN), mild cognitive impairment (MCI), and dementia. All underwent 3.0-T MRI, [ A total of 148 individuals were included (58 CN, 39 MCI, 38 AD dementia, and 13 other dementia). Significant associations appeared only in APOE ε4 carriers ( Downregulated proteasome activity is strongly associated with amyloid burden, early tau accumulation, hippocampal atrophy, and cognitive impairment only in APOE ε4 carriers. These findings suggest that plasma proteasome activity may serve as a noninvasive marker of AD-related vulnerability in genetically at-risk individuals. Further studies are needed to clarify whether proteasome activity contributes to or results from amyloid and tau aggregation. KCT0005428. Registered September 24, 2020. Study subjects included in this analysis were those recruited from November 2018 onwards (retrospectively registered). The online version contains supplementary material available at 10.1186/s13195-026-01994-w. Show less

Vascular inflammation contributes to the development of many chronic human diseases. Inflammatory stimuli such as interleukin (IL)-1β or disturbed blood flow trigger endothelial activation, thereby promoting leukocyte recruitment and transmigration through inflammatory signaling pathways. This study aimed to identify novel compounds capable of blocking vascular inflammation, with potential therapeutic applications in vascular inflammatory diseases such as atherosclerosis. A natural compound library was screened to identify drug candidates that inhibit IL-1β-induced endothelial inflammation. The anti-inflammatory effects of tigloylgomisin P, one of the hit compounds, were examined in bovine aortic endothelial cells stimulated with IL-1β or oscillatory (disturbed) flow. Endothelial inflammation was assessed by measuring nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) phosphorylation and nuclear translocation, monocyte adhesion to endothelial monolayers, and Smad1/5/9 phosphorylation Tigloylgomisin P suppressed IL-1β-induced NF-κB activation and reduced monocyte adhesion. In addition, it inhibited oscillatory shear stress-induced endothelial inflammation mediated by NF-κB activation and Smad1/5/9 phosphorylation. In ApoE knockout mice, administration of tigloylgomisin P decreased inflammatory marker expression in the atheroprone inner curvature of aortic arches. These findings suggest that tigloylgomisin P may represent a potential therapeutic agent for vascular inflammatory diseases such as atherosclerosis. Show less

Vascular damage, including cerebral amyloid angiopathy (CAA) and non-amyloid cerebral small vessel disease (CSVD), has been linked to glymphatic dysfunction, which may contribute to Alzheimer's disease (AD) pathology and cognitive decline. We investigated the associations among vascular damage, glymphatic function measured by the DTI-ALPS (Diffusion Tensor Imaging-Analysis Along the Perivascular Space) index, AD plasma biomarkers, and cognitive decline. This study includes 1,249 participants recruited from Samsung Medical Center. We performed linear regression analysis to identify factors associated with the DTI-ALPS index. Further, linear regression analysis with vascular imaging markers, including CAA and CSVD summary scores, as predictors and DTI-ALPS index as an outcome was performed to investigate the effect of vascular pathology on glymphatic function. We conducted mediation analyses to investigate whether the DTI-ALPS index mediates the effect of vascular imaging markers on plasma biomarkers (phosphorylated tau 217 [p-tau 217], glial fibrillary acidic protein [GFAP], and neurofilament light chain [NFL]). Additionally, mediation analyses with the DTI-ALPS index as a predictor, each plasma biomarker as a mediator, and annual MMSE or CDR-SOB change as an outcome to investigate whether plasma biomarkers mediate the effect of the DTI-ALPS index on longitudinal cognitive decline. First, the DTI-ALPS index was negatively associated with both CAA (β [95% CI] = -0.163 [-0.214, -0.112], p < 0.0001) and CSVD (β [95% CI] = -0.195 [-0.247, -0.143], p < 0.0001) summary scores after controlling for age, sex, BMI status, and APOE genotype. Second, the DTI-ALPS index fully mediated the relationship between these vascular markers and p-tau 217 (CSVD summary score, indirect effect β [95% CI] = 0.016 [0.010, 0.023], p < 0.001; CAA summary score, indirect effect β [95% CI] = 0.013 [0.008, 0.020], p < 0.001) and GFAP (CSVD summary score, indirect effect β [95% CI] = 0.015 [0.008, 0.022], p < 0.001; CAA summary score, indirect effect β [95% CI] = 0.012 [0.007, 0.019], p < 0.001), while partially mediating the relationship for NFL, regardless of Aβ uptake on PET. Finally, the DTI-ALPS index was significantly associated with cognitive decline and this association was partially mediated by plasma biomarkers. These findings highlight glymphatic dysfunction as a key mechanism linking vascular pathology with tau, inflammation and neurodegeneration, independent of Aβ uptakes. Show less

Purinergic receptor P2X7 has been considered as a potential new target for detecting and treating high-risk plaque. Nanobodies are the smallest antibody fragments with high antigen binding ability and specificity, which are well-suited for radionuclide imaging. The present study aimed to develop a novel P2X7-targeted nanobody SPECT tracer and to investigate its potential for identification of atherosclerotic plaque (AP). The anti-P2X7 nanobody 1c81 was site-specifically conjugated with [ Show less

Aberrant deposition of β-amyloid (Aβ) and hyperphosphorylated tau, along with neuroinflammation, are key drivers of Alzheimer's disease (AD) pathology. Here, we identify ramalin, a natural antioxidant, as a promising therapeutic agent that alleviates AD pathology by modulating β-site APP cleaving enzyme 1 (BACE1), histone deacetylase 6 (HDAC6), and the mitogen-activated protein kinases (MAPK) pathway. Ramalin reduced BACE1 protein levels, independently of its transcription, translation, or enzymatic activity, an effect mediated by inhibition of HDAC6. Consistently, HDAC6 knockout similarly decreased BACE1 levels, highlighting HDAC6 as a key regulator of BACE1. Ramalin further suppressed neuroinflammatory responses by downregulating inducible nitric oxide synthase (iNOS) and the NLR family pyrin domain containing 3 (NLRP3) inflammasome. In AD mouse models, ramalin treatment significantly attenuated neuroinflammation, Aβ plaque burden, and tau hyperphosphorylation, while improving cognitive performance. Notably, ramalin reversed Aβ oligomer-induced synaptic transmission impairment and restored synaptic vesicle recycling in hippocampal neurons. Transcriptomic analysis identified modulation of the MAPK pathway, with reduced phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) implicated in tau pathology. These findings establish ramalin as a disease-modifying intervention that provides neuroprotection through concurrent regulation of BACE1, HDAC6, and MAPK signaling pathway. Collectively, our findings highlight ramalin as a compelling disease-modifying candidate with the potential to drive a breakthrough approach targeting AD pathology. Show less

Lipoprotein(a) [Lp(a)] is a causal, genetically determined risk factor for atherosclerotic cardiovascular disease (ASCVD) and calcific aortic valve stenosis (CAVS). Although elevated Lp(a) affects approximately 20% of the global population, specific pharmacological options have long been unavailable, leaving a major gap in residual risk management. This review synthesizes current understanding of Lp(a) molecular architecture, genetics, and metabolism, and integrates mechanistic evidence linking Lp(a) to pro-atherogenic, pro-inflammatory, and pro-thrombotic pathways. We summarize epidemiological and genetic data associating Lp(a) with a broad spectrum of cardiovascular outcomes and discuss current clinical guidelines on screening and risk stratification. Furthermore, we provide an up-to-date overview of the emerging therapeutic landscape, including RNA-targeted therapies and novel oral small molecules. With pivotal phase 3 outcome trials nearing completion, the field is transitioning from viewing Lp(a) as an untreatable biomarker to an actionable therapeutic target, with important implications for precision cardiovascular prevention. Show less

SORT1 (sortilin 1), a member of the the Vps10 (vacuolar protein sorting 10) family, is involved in hepatic lipid metabolism by regulating very low-density lipoprotein (VLDL) secretion and facilitating the lysosomal degradation of CES1 (carboxylesterase 1), crucial for triglyceride (TG) breakdown in the liver. This study explores whether SORT1 is targeted for degradation by chaperone-mediated autophagy (CMA), a selective protein degradation pathway that directs proteins containing KFERQ-like motifs to lysosomes via LAMP2A (lysosomal-associated membrane protein 2A). Silencing LAMP2A or HSPA8/Hsc70 with siRNA increased cytosolic SORT1 protein levels. Leupeptin treatment induced lysosomal accumulation of SORT1, unaffected by si Show less

β-secretase (BACE1) is instrumental in amyloid-β (Aβ) production, with overexpression noted in Alzheimer's disease (AD) neuropathology. The interaction of Aβ with the receptor for advanced glycation endproducts (RAGE) facilitates cerebral uptake of Aβ and exacerbates its neurotoxicity and neuroinflammation, further augmenting BACE1 expression. Given the limitations of previous BACE1 inhibition efforts, the study explores reducing BACE1 expression to mitigate AD pathology. The research reveals that the anticancer agent 6-thioguanosine (6-TG) markedly diminishes BACE1 expression without eliciting cytotoxicity while enhancing microglial phagocytic activity, and ameliorate cognitive impairments with reducing Aβ accumulation in AD mice. Leveraging advanced deep learning-based tool for target identification, and corroborating with surface plasmon resonance assays, it is elucidated that 6-TG directly interacts with RAGE, modulating BACE1 expression through the JAK2-STAT1 pathway and elevating soluble RAGE (sRAGE) levels in the brain. The findings illuminate the therapeutic potential of 6-TG in ameliorating AD manifestations and advocate for small molecule strategies to increase brain sRAGE levels, offering a strategic alternative to the challenges posed by the complexity of AD. Show less

This study elucidated the regulatory mechanisms of age-related meat flavor precursors in naturally grazed Sunit sheep of different ages (6, 18, and 30 months) by analyzing their metabolite and mRNA profiles. The longissimus dorsi muscle was sampled from each group and subjected to metabolomics and transcriptomics analyses. A total of 395 differential metabolites (DMs) and 1482 differentially expressed genes (DEGs) were detected across the age groups. As the age increased, the expression levels of Show less

Glycoprotein non-metastatic melanoma protein B (GPNMB) is a transmembrane glycoprotein that differentially regulates tissue homeostasis and disease pathogenesis. In physiological contexts, it maintains melanosome biogenesis, osteogenesis, and neuroprotection through domain-specific interactions. Pathologically, tumors exploit GPNMB's dual mechanisms: membrane-bound isoforms mediate T cell exclusion via DC-HIL/Syndecan-4, while soluble GPNMB(sGPNMB) promote metabolic reprogramming through CD44/NF-κB. Clinically, GPNMB overexpression correlates with poor outcomes, notably demonstrating 40% versus 8% ADC response in high- versus low-expressing TNBC (p < 0.001). Emerging data reveal its crosstalk with HER2/FGFR1 pathways and identify K48-ubiquitination as a therapeutic resistance mechanism. These findings position domain-selective GPNMB targeting as a promising precision oncology strategy. Show less

Adipose tissue metabolism plays a crucial role in sheep meat quality and the optimization of adipose tissue utilization. To reveal the molecular mechanisms of adipose tissue metabolism during growth in naturally grazing sheep, we investigated the mRNA and miRNA profiles in subcutaneous adipose tissue (SAT) from naturally grazing Sunit sheep at 6, 18, and 30 months of age (Mth-6, Mth-18, and Mth-30). We identified 927 differentially expressed (DE) genes and 134 DE miRNAs in the SAT of sheep at different growth stages. Specifically, the expressions of Show less

Accelerated population aging and rising incidence of bone defects have intensified the need for advanced bone regeneration strategies. While tissue-engineered scaffolds fabricated via 3D printing offer promising alternatives to conventional grafts, most techniques fail to replicate the multi-scale fibrous architecture of native bone extracellular matrix, limiting their biofunctionality. To address this, we developed a hybrid manufacturing strategy integrating low-temperature thermally induced phase separation with extrusion-based 3D printing of polylactic acid (PLA) scaffolds. By optimizing solvent ratios (THF: DMF = 3:1) and freezing temperatures (-196 °C-4 °C), we produced scaffolds with tunable micro-nano fibrous surfaces and macroporous structures. Key findings revealed that scaffolds processed at -196 °C (PLA-196) exhibited the highest porosity (pore size: 6.01 ± 2.06 μm), superior hydrophilicity, and enhanced compressive modulus. These scaffolds significantly promoted BMSC adhesion, proliferation, and osteogenic differentiation via activation of Show less

Raddeanin A is a triterpenoid isolated from Anemone raddeana Regel. It exhibits a broad spectrum of biological activities such as anti-tumor and anti-inflammatory, however, its neuroprotective effect in targeting Alzheimer's disease (AD) remains uninvestigated. To provide scientific base for the development of novel AD drug by clarifying the neuroprotective effect and molecular mechanisms of raddeanin A in both in vitro and in vivo AD model. To confirm the neuroprotective role of raddeanin A in the treatment of AD, its mechanisms and effects on β-amyloidosis and Aβ fibrillation was studied in U87 cells. Besides, the improvement on cognitive deficit, pathological defects, reactive astrocyte clusters, inhibition on neuronal inflammation and apoptosis were further studied in 3 x Tg-AD mice model of AD. Real-time PCR, western blot, dot blot, biolayer interferometry and bioinformatics analysis were used to confirm the in vitro effect and targets of raddeanin A on β-amyloidosis and its associated protein network. A series of experiments including Morris water maze, H&E staining, nissl staining and immunofluorescence analysis were conducted to confirm the protective behavioral effect of raddeanin A in the in vivo AD mice model. Raddeanin A was identified to reduce β-amyloidosis in U87 cells and 3 x Tg-AD mice model of AD by decreasing level of BACE1, APP, APP-β and Aβ. Raddeanin A improved behavioral, spatial memory and learning ability in the AD mice. In the cortex and hippocampus, raddeanin A improved the morphology and arrangement of neurons, lower the level of reactive astrocyte marker GFAP and apoptotic marker proteins Bax/Bcl2 ratio. Moreover, raddeanin A upregulated the mRNA and protein level of Prkcα in the hippocampus of AD mice whose neuroprotective effect was exerted possibly via the activation of protein kinase C. As a novel natural agent targeting β-amyloidosis, our results provide the first evidence of the multiple in vitro and in vivo neuroprotective effect of raddeanin A, suggesting its potential therapeutic application in preventing or alleviating the symptoms of AD. Show less

Kawasaki disease (KD) is an acute vasculitis that primarily affects children under age 5 years. Approximately 20-25% of untreated children with KD and 3-5% of those treated with intravenous immunoglobulin therapy develop coronary artery aneurysms (CAAs). The prevalence of CAAs is much higher in male than in female patients with KD, but the underlying factors contributing to susceptibility to CAAs in patients with KD remain unclear. This study aimed to identify sex-specific susceptibility loci associated with CAAs in KD patients. A sex-stratified genome-wide association study (GWAS) was performed using previously obtained GWAS data from 296 KD patients and a new replication study in an independent set of 976 KD patients by comparing KD patients without CAA (controls) and KD patients with aneurysms (internal diameter ≥5 mm) (cases). Six male-specific susceptibility loci, A sex-stratified GWAS identified 6 male-specific ( Show less

Depressive mood is a major psychiatric symptom that causes serious disturbances in daily life. Unlike physical symptoms, psychiatric symptoms are more difficult to evaluate objectively. Therefore, we aimed to discover biomarkers that reflect changes in serum protein metabolism during a clinical depressive mood. Serum protein profiling was conducted in participants who were not experiencing a current depressive episode (healthy individuals and patients in remission). Serum proteins were identified and quantified using liquid chromatography-tandem mass spectrometry. Differentially expressed proteins with a Apolipoprotein A-IV levels were lower in the group with a current episode of depression than in the remission and healthy control groups. Further, fibronectin levels were also lower in the group with a current episode of depression than in the healthy control group but not in the remission group. We found that apolipoprotein A-IV-mediated inflammation is involved in clinical depressive moods, possibly by inducing neurological changes in the brain. Therefore, apolipoprotein A-IV and fibronectin levels may be explored as potentially novel biomarkers for detecting a current episode of depression. Show less

Protein Phosphatase 4 Catalytic Subunit (PPP4C) is an evolutionarily conserved protein involved in multiple biological and pathological events, including embryogenesis, organogenesis, cellular homeostasis, and oncogenesis. However, the detailed mechanisms underlying these processes remain largely unknown. Thus, we investigated the potential correlation between PPP4C and biological processes (BPs) and canonical Wnt signaling using pan-cancer analysis and Xenopus laevis (X. laevis) embryo model. Our results indicate that PPP4C is a potential biomarker for specific cancer types due to its high diagnostic accuracy and significant prognostic correlation. Furthermore, in multiple cancer types, PPP4C-related differentially expressed genes (DEGs) were significantly enriched in pattern specification, morphogenesis, and canonical Wnt activation. Consistently, perturbation of Ppp4c in X. laevis embryos interfered with normal embryogenesis and canonical Wnt responses. Moreover, biochemical analysis of X. laevis embryos demonstrated that both endogenous and exogenous Ppp4c negatively regulated AXIN1 (Wnt inhibitor) abundance. This study provides novel insights into PPP4C roles in pattern specification and Wnt activation. The similarities in BPs and Wnt signaling regulation regarding PPP4C support the intrinsic link between tumorigenesis and early embryogenesis. Show less

KMT2A (11q23.3) gene rearrangements are found in acute leukemia and are associated with a poor or intermediate prognosis. MLLT10 is the fourth most common gene fusion partner for KMT2A. A reciprocal translocation t(10;11) is insufficient to produce an in-frame KMT2A/MLLT10 fusion, because the genes involved in the rearrangement have opposite transcriptional orientations. In order to bring KMT2A and MLLT10 into juxtaposition, complex rearrangements are required. Until now, conventional chromosome, fluorescence in situ hybridization (FISH), and reverse transcriptase-polymerase chain reaction (RT-PCR) studies have been used to detect KMT2A/MLLT10 fusions. However, conventional studies have limitations, such as poor and inconsistent resolution, when compared to next-generation sequencing (NGS). In this study, we report a pediatric patient with acute megakaryoblastic leukemia, in whom the cryptic KMT2A/MLLT10 fusion was not detected by KMT2A break-apart probe FISH and chromosome analysis, but detected by NGS. In this patient, NGS showed cryptic insertion of MLLT10 exons 9-24 into intron 9 of KMT2A, resulting in a KMT2A/MLLT10 fusion. Therefore, NGS is a valuable complementary option for the evaluation of structural aberrations, especially those with a cryptic size. Show less

Melanocortin-4 receptors (MC4Rs) expressed by the central nervous system are essential regulators of energy homeostasis, and Mc4r mutation is the most common cause of human monogenic obesity. Notably, patients with obesity carrying Mc4r mutations are protected against obesity-induced hypertension, and MC4R agonists elevate blood pressure (BP). Although increased sympathetic tone by MC4Rs is suggested to underlie this phenotype, the detailed mechanisms remain unclear. Here, we investigate how MC4Rs regulate the sympathetic preganglionic neurons and find that MC4Rs activate these neurons via the protein kinase A-dependent activation of the transient receptor potential vanilloid 1 (TRPV1) channel. Importantly, we demonstrate that the inhibition of TRPV1 prevents MC4R-induced elevation of BP but does not affect MC4R-induced anorexia. We further show that TRPV1 is responsible for MC4R-dependent activation of the sympathetic preganglionic neurons by high-fat diet. Together, our results provide insight into how MC4Rs regulate sympathetic function. Show less

Alcohol consumption is associated with a high increased lipid profile and this association may depend on genetic risk factors. In this study, we aimed to assess the effects of genetic variation associated with alcohol consumption on lipid profiles using data from two Korean population studies. We performed a genotype association study using the HEXA (n = 51,349) and KNHANES (n = 9158) data. Genotype analyses of the two sets of Korean population data showed associations of increased total cholesterol and high-density lipoprotein (HDL)-cholesterol with CETP rs708272. The HEXA and KNHANES populations revealed differences in HDL cholesterol according to the presence of CETP rs708272, independent of ALDH2 rs671 and alcohol consumption. In contrast, total cholesterol levels were associated with alcohol consumption and ALDH2 rs671 in men with CETP rs708272 (CT and TT genotypes). Furthermore, in drinkers with ALDH2 rs671 (GA and AA genotypes), higher total cholesterol was associated with the CETP rs708272 TT minor homozygous genotype based on both HEXA and KNHANES data. Our findings demonstrated that alcohol consumption and genetic variation in either CETP or ALDH2 may be associated with cholesterol levels. We hope these findings will provide a better understanding of the relationship between alcohol consumption and cholesterol according to each individual's genetic background. Show less

Repetitive low-level blast exposure is one of the major occupational health concerns among US military service members and law enforcement. This study seeks to identify gene expression using microRNA and RNA sequencing in whole-blood samples from experienced breachers and unexposed controls. We performed experimental RNA sequencing using Illumina’s HiSeq 2500 Sequencing System, and microRNA analysis using NanoString Technology nCounter miRNA expression panel in whole-blood total RNA samples from 15 experienced breachers and 14 age-, sex-, and race-matched unexposed controls. We identified 10 significantly dysregulated genes between experienced breachers and unexposed controls, with FDR corrected <0.05: One upregulated gene, LINC00996 (long intergenic non-protein coding RNA 996); and nine downregulated genes, IGLV3-16 (immunoglobulin lambda variable 3-16), CD200 (CD200 molecule), LILRB5 (leukocyte immunoglobulin-like receptor B5), ZNF667-AS1 (ZNF667 antisense RNA 1), LMOD1 (leiomodin 1), CNTNAP2 (contactin-associated protein 2), EVPL (envoplakin), DPF3 (double PHD fingers 3), and IGHV4-34 (immunoglobulin heavy variable 4-34). The dysregulated gene expressions reported here have been associated with chronic inflammation and immune response, suggesting that these pathways may relate to the risk of lasting neurological symptoms following high exposures to blast over a career. Show less

The epithelial-mesenchymal transition (EMT) comprises an important biological mechanism not only for cancer progression but also in the therapeutic resistance of cancer cells. While the importance of the protein abundance of EMT-inducers, such as Snail (SNAI1) and Zeb1 (ZEB1), during EMT progression is clear, the reciprocal interactions between the untranslated regions (UTRs) of EMT-inducers via a competing endogenous RNA (ceRNA) network have received little attention. In this study, we found a synchronized transcript abundance of Snail and Zeb1 mediated by a non-coding RNA network in colorectal cancer (CRC). Importantly, the Show less

Efficient catabolic metabolism of adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide phosphate (NADPH) is essentially required for cancer cell survival, especially in metastatic cancer progression. Epithelial-mesenchymal transition (EMT) plays an important role in metabolic rewiring of cancer cells as well as in phenotypic conversion and therapeutic resistance. Snail (SNAI1), a well-known inducer of cancer EMT, is critical in providing ATP and NADPH via suppression of several gatekeeper genes involving catabolic metabolism, such as phosphofructokinase 1 (PFK1), fructose-1,6-bisphosphatase 1 (FBP1), and acetyl-CoA carboxylase 2 (ACC2). Paradoxically, PFK1 and FBP1 are counter-opposing and rate-limiting reaction enzymes of glycolysis and gluconeogenesis, respectively. In this study, we report a distinct metabolic circuit of catabolic metabolism in breast cancer subtypes. Interestingly, PFKP and FBP1 are inversely correlated in clinical samples, indicating different metabolic subsets of breast cancer. The luminal types of breast cancer consist of the pentose phosphate pathway (PPP) subset by suppression of PFKP while the basal-like subtype (also known as triple negative breast cancer, TNBC) mainly utilizes glycolysis and mitochondrial fatty acid oxidation (FAO) by loss of FBP1 and ACC2. Notably, PPP remains active via upregulation of TIGAR in the FBP1-loss basal-like subset, indicating the importance of PPP in catabolic cancer metabolism. These results indicate different catabolic metabolic circuits and thus therapeutic strategies in breast cancer subsets. Show less

Despite the importance of mitochondrial fatty acid oxidation (FAO) in cancer metabolism, the biological mechanisms responsible for the FAO in cancer and therapeutic intervention based on catabolic metabolism are not well defined. In this study, we observe that Snail (SNAI1), a key transcriptional repressor of epithelial-mesenchymal transition, enhances catabolic FAO, allowing pro-survival of breast cancer cells in a starved environment. Mechanistically, Snail suppresses mitochondrial ACC2 (ACACB) by binding to a series of E-boxes located in its proximal promoter, resulting in decreased malonyl-CoA level. Malonyl-CoA being a well-known endogenous inhibitor of fatty acid transporter carnitine palmitoyltransferase 1 (CPT1), the suppression of ACC2 by Snail activates CPT1-dependent FAO, generating ATP and decreasing NADPH consumption. Importantly, combinatorial pharmacologic inhibition of pentose phosphate pathway and FAO with clinically available drugs efficiently reverts Snail-mediated metabolic reprogramming and suppresses in vivo metastatic progression of breast cancer cells. Our observations provide not only a mechanistic link between epithelial-mesenchymal transition and catabolic rewiring but also a novel catabolism-based therapeutic approach for inhibition of cancer progression. Show less

Various molecular targeted therapies and diagnostic modalities have been developed for the treatment of hepatocellular carcinoma (HCC); however, HCC still remains a difficult malignancy to cure. Recently, the focus has shifted to cancer metabolism for the diagnosis and treatment of various cancers, including HCC. In addition to conventional diagnostics, the measurement of enhanced tumor cell metabolism using F-18 fluorodeoxyglucose (18F-FDG) for increased glycolysis or C-11 acetate for fatty acid synthesis by positron emission tomography/computed tomography (PET/CT) is well established for clinical management of HCC. Unlike tumors displaying the Warburg effect, HCCs vary substantially in terms of 18F-FDG uptake, which considerably reduces the sensitivity for tumor detection. Accordingly, C-11 acetate has been proposed as a complementary radiotracer for detecting tumors that are not identified by 18F-FDG. In addition to HCC diagnosis, since the degree of 18F-FDG uptake converted to standardized uptake value (SUV) correlates well with tumor aggressiveness, 18F-FDG PET/CT scans can predict patient outcomes such as treatment response and survival with an inverse relationship between SUV and survival. The loss of tumor suppressor genes or activation of oncogenes plays an important role in promoting HCC development, and might be involved in the "metabolic reprogramming" of cancer cells. Mutations in various genes such as Show less

Gastric cancer (GC) is the second cause of cancer-related death. Cisplatin (CDDP) is widely used as the standard GC treatment, but relapse and metastasis are common because of intrinsic or acquired drug resistance. The mitogen-activated protein kinase phosphatases (MAPK)-extracellular signal regulated kinases (ERK) pathway contributes to GC progression and drug resistance, but targeting the MAPK-ERK pathway is challenging in GC therapy. Here, we demonstrated that dual-specificity phosphatases 6 (DUSP6) was overexpressed in GC and predicted poor overall survival and progression-free survival. Knockdown DUSP6 inhibited GC proliferation, migration, invasion and induced apoptosis. (E/Z)-BCI hydrochloride (BCI), a DUSP6 small molecule inhibitor, increased the activity of ERK but interestingly decreased the expression of ERK response genes in BGC823, SGC7901 and CDDP-resistant SGC7901/DDP cells. BCI also caused cell death through the DNA damage response (DDR) pathway. Moreover, BCI inhibited cell proliferation, migration and invasion in a receptor-independent manner and enhanced CDDP cytotoxicity at pharmacological concentrations in the GC cells. In vivo experiments further showed that BCI enhances the antitumor effects of CDDP in cell-based xenografts and PDX models. In summary, our findings indicated that disruption of DUSP6 by BCI enhanced CDDP-induced cell death and apoptosis in GC may partly through ERK and DDR pathways. Thus, this study suggests that DUSP6 is a potential prognostic biomarker and a promising target for GC therapy. Show less