76 research outputs found
SINGLE-STEP INDUCTION OF RIGHT-SIDED COLON CANCER PHENOTYPE BY BRAFV600E THROUGH ACQUIRED WNT ACTIVATION
BRAF mutant colorectal cancers (CRC) mostly arise via an alternate pathway distinguished from the classical adenoma-carcinoma sequence involving APC and KRAS mutations. BRAF-driven tumors have an increased incidence of promoter CpG island methylator phenotype (CIMP)-high, microsatellite instable (MSI) phenotype, lack of concurrent mutations of APC, mucinous histology, and location on the right side of the colon. Although these characteristics are constantly observed in BRAF mutant CRCs, how this BRAF mutation induces this type of tumor is not clear.
To understand this, we modeled the early carcinogenesis of colorectal cancer by inducing BRAFV600E and KRASG12D individually in organoids prepared from mouse proximal colon and subsequently determined the genome-wide gene expression, DNA methylation, and genetic changes in combination with growth properties and induction of tumor formation.
The BRAFV600E, but not KRASG12D, mutations induced various features of progressive transformation consisting of increased spheroid formation of the organoids with internal dysplastic polypoid growth. BRAFV600E organoids acquired an ability to grow without stem cell niche factors such as Wnt3a, R-Spondin and Noggin. These above phenotypic changes are phenocopies of APC mutations in organoids wherein the Wnt pathway is activated. Indeed, BRAFV600E drives sustained up-regulation of Wnt targets and stem cell genes and suppression of differentiation genes regardless of whether niche factors are added. Furthermore, in some of the transformed organoids, sequencing revealed mutations in -catenin. Finally, and most excitingly, induction of BRAFV600E, but not KRASG12D, induced complete transformation forming xenograft tumors in immunodeficient mice. The tumors exhibit histological characteristics of mucinous adenocarcinoma, which is highly associated with the BRAFV600E mutation in human CRCs. In addition, analyses of genome-wide methylation revealed increased DNA methylation in CpG island promoters of many genes including Wnt negative regulators such as Sfrp1, Sfrp2, Wt1 and Sox17 and CIMP genes including p16 and Igfbp7 in the BRAFV600E mutant organoids.
In conclusion, mouse colon organoids expressing BRAFV600E recapitulate features of the human right-sided CRC phenotype with adoption of a stem cell niche factor independency, activation of the Wnt pathway, induction of CpG island methylation in Wnt negative regulators and CIMP panel genes, and activating Wnt-pathway mutations
Depression and suicide risk prediction models using blood-derived multi-omics data
More than 300 million people worldwide experience depression; annually, ~800,000 people die by suicide. Unfortunately, conventional interview-based diagnosis is insufficient to accurately predict a psychiatric status. We developed machine learning models to predict depression and suicide risk using blood methylome and transcriptome data from 56 suicide attempters (SAs), 39 patients with major depressive disorder (MDD), and 87 healthy controls. Our random forest classifiers showed accuracies of 92.6% in distinguishing SAs from MDD patients, 87.3% in distinguishing MDD patients from controls, and 86.7% in distinguishing SAs from controls. We also developed regression models for predicting psychiatric scales with R2 values of 0.961 and 0.943 for Hamilton Rating Scale for Depression???17 and Scale for Suicide Ideation, respectively. Multi-omics data were used to construct psychiatric status prediction models for improved mental health treatment
Echovirus 30 Induced Neuronal Cell Death through TRIO-RhoA Signaling Activation
BACKGROUND: Echovirus 30 (Echo30) is one of the most frequently identified human enteroviruses (EVs) causing aseptic meningitis and encephalitis. However the mechanism underlying the pathogenesis of Echo30 infection with significant clinical outcomes is not completely understood. The aim of this investigation is to illustrate molecular pathologic alteration in neuronal cells induced by Echo30 infection using clinical isolate from young patient with neurologic involvement. METHODOLOGY/PRINCIPAL FINDINGS: To characterize the neuronal cellular response to Echo30 infection, we performed a proteomic analysis based on two-dimensional gel electrophoresis (2-DE) and MALDI-TOF/TOF Mass Spectrophotometric (MS) analysis. We identified significant alteration of several protein expression levels in Echo30-infected SK-N-SH cells. Among these proteins, we focused on an outstanding up-regulation of Triple functional domain (TRIO) in Echo30-infected SK-N-SH cells. Generally, TRIO acts as a key component in the regulation of axon guidance and cell migration. In this study, we determined that TRIO plays a role in the novel pathways in Echo30 induced neuronal cell death. CONCLUSIONS/SIGNIFICANCE: Our finding shows that TRIO plays a critical role in neuronal cell death by Echo30 infection. Echo30 infection activates TRIO-guanine nucleotide exchange factor (GEF) domains (GEFD2) and RhoA signaling in turn. These results suggest that Echo30 infection induced neuronal cell death by activation of the TRIO-RhoA signaling. We expect the regulation of TRIO-RhoA signaling may represent a new therapeutic approach in treating aseptic meningitis and encephalitis induced by Echo30
Machine learning models of clinically relevant biomarkers for the prediction of stable obstructive coronary artery disease
BackgroundIn patients with suspected obstructive coronary artery disease (CAD), evaluation using a pre-test probability model is the key element for diagnosis; however, its accuracy is controversial. This study aimed to develop machine learning (ML) models using clinically relevant biomarkers to predict the presence of stable obstructive CAD and to compare ML models with an established pre-test probability of CAD models.MethodsEight machine learning models for prediction of obstructive CAD were trained on a cohort of 1,312 patients [randomly split into the training (80%) and internal validation sets (20%)]. Twelve clinical and blood biomarker features assessed on admission were used to inform the models. We compared the best-performing ML model and established the pre-test probability of CAD (updated Diamond-Forrester and CAD consortium) models.ResultsThe CatBoost algorithm model showed the best performance (area under the receiver operating characteristics, AUROC, 0.796, and 95% confidence interval, CI, 0.740–0.853; Matthews correlation coefficient, MCC, 0.448) compared to the seven other algorithms. The CatBoost algorithm model improved risk prediction compared with the CAD consortium clinical model (AUROC 0.727; 95% CI 0.664–0.789; MCC 0.313). The accuracy of the ML model was 74.6%. Age, sex, hypertension, high-sensitivity cardiac troponin T, hemoglobin A1c, triglyceride, and high-density lipoprotein cholesterol levels contributed most to obstructive CAD prediction.ConclusionThe ML models using clinically relevant biomarkers provided high accuracy for stable obstructive CAD prediction. In real-world practice, employing such an approach could improve discrimination of patients with suspected obstructive CAD and help select appropriate non-invasive testing for ischemia
Added Value of Coronal Reformations for Duty Radiologists and for Referring Physicians or Surgeons in the CT Diagnosis of Acute Appendicitis
Implantation of canine umbilical cord blood-derived mesenchymal stem cells mixed with beta-tricalcium phosphate enhances osteogenesis in bone defect model dogs
This study was performed to evaluate the osteogenic effect of allogenic canine umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) mixed with beta-tricalcium phosphate (β-TCP) in orthotopic implantation. Seven hundred milligrams of β-TCP mixed with 1 × 106 UCB-MSCs diluted with 0.5 ml of saline (group CM) and mixed with the same volume of saline as control (group C) were implanted into a 1.5 cm diaphyseal defect and wrapped with PLGC membrane in the radius of Beagle dogs. Radiographs of the antebrachium were made after surgery. The implants were harvested 12 weeks after implantation and specimens were stained with H&E, toluidine blue and Villanueva-Goldner stains for histological examination and histomorphometric analysis of new bone formation. Additionally, UCB-MSCs were applied to a dog with non-union fracture. Radiographically, continuity between implant and host bone was evident at only one of six interfaces in group C by 12 weeks, but in three of six interfaces in group CM. Radiolucency was found only near the bone end in group C at 12 weeks after implantation, but in the entire graft in group CM. Histologically, bone formation was observed around β-TCP in longitudinal sections of implant in both groups. Histomorphometric analysis revealed significantly increased new bone formation in group CM at 12 weeks after implantation (p < 0.05). When applied to the non-union fracture, fracture healing was identified by 6 weeks after injection of UCB-MSCs. The present study indicates that a mixture of UCB-MSCs and β-TCP is a promising osteogenic material for repairing bone defects
The Feasibility and Safety of the Endoscopic Submucosal Dissection of Superficial Gastric Neoplastic Lesions in Patients with Compensated Liver Cirrhosis: A Retrospective Study
Clinical and epidemiological characteristics of Korean patients with hepatitis C virus genotype 6
Background/AimsThe distribution of hepatitis C virus (HCV) genotypes varies geographically. In Korea, genotypes 1 and 2 comprise more than 90% of HCV infections, while genotype 6 is very rare. This study compared the clinical and epidemiological characteristics of patients with genotype 6 HCV infection with those infected with HCV genotypes 1 and 2.MethodsThis was a prospective, multicenter HCV cohort study that enrolled 1,173 adult patients, of which 930 underwent HCV genotype analysis, and only 9 (1.0%) were found to be infected with genotype 6 HCV. The clinical and epidemiological parameters of the genotypes were compared.ResultsThe patients with genotype 6 HCV had a mean age of 41.5 years, 77.8% were male, and they had no distinct laboratory features. A sustained virologic response (SVR) was observed in four (67%) of six patients who received antiviral therapy. Risk factors such as the presence of a tattoo (n=6, 66.7%), more than three sexual partners (n=3, 33.3%), and injection drug use (n=3, 33.3%) were more common among genotype 6 patients than among genotypes 1 or 2.ConclusionsThe epidemiology and treatment response of patients infected with genotype 6 HCV differed significantly from those with genotypes 1 or 2, warranting continuous monitoring
Enterovirus 71-associated hand, foot and mouth diseases with neurologic symptoms, a university hospital experience in Korea, 2009
PurposeHand-foot-mouth disease (HFMD) is a common viral illness in children, which is usually mild and self-limiting. However, in recent epidemics of HFMD in Asia, enterovirus 71 (EV71) has been recognized as a causative agent with severe neurological symptoms with or without cardiopulmonary involvement. HFMD was epidemic in Korea in the spring of 2009. Severe cases with complications including death have been reported. The clinical characteristics in children with neurologic manifestations of EV71 were studied in Ewha Womans University Mokdong Hospital.MethodsExaminations for EV71 were performed from the stools, respiratory secretion or CSF of children who presented neurologic symptoms associated with HFMD by realtime PCR. Clinical and radiologic data of the patients were collected and analyzed.ResultsEV71 was isolated from the stool of 16 patients but not from respiratory secretion or CSF. Among the 16 patients, meningitis (n=10) was the most common manifestation, followed by Guillain-Barré syndrome (n=3), meningoencephalitis (n=2), poliomyelitis-like paralytic disease (n=1), and myoclonus (n=1). Gene analysis showed that most of them were caused by EV71 subgenotype C4a, which was prevalent in China in 2008.ConclusionBecause EV71 causes severe complications and death in children, a surveillance system to predict upcoming outbreaks should be established and maintained and adequate public health measures are needed to control disease
Effect of a Dipeptidyl Peptidase-IV Inhibitor, Des-Fluoro-Sitagliptin, on Neointimal Formation after Balloon Injury in Rats
Background: Recently, it has been suggested that enhancement of incretin effect improves cardiac function. We investigated the effect of a DPP-IV inhibitor, des-fluoro-sitagliptin, in reducing occurrence of restenosis in carotid artery in response to balloon injury and the related mechanisms. Methods and Findings: Otsuka Long-Evans Tokushima Fatty rats were grouped into four: control (normal saline) and sitagliptin 100, 250 and 500 mg/kg per day (n = 10 per group). Sitagliptin or normal saline were given orally from 1 week before to 2 weeks after carotid injury. After 3 weeks of treatment, sitagliptin treatment caused a significant and dose-dependent reduction in intima-media ratio (IMR) in obese diabetic rats. This effect was accompanied by improved glucose homeostasis, decreased circulating levels of high-sensitivity C-reactive protein (hsCRP) and increased adiponectin level. Moreover, decreased IMR was correlated significantly with reduced hsCRP, tumor necrosis factor- and monocyte chemoattractant protein-1 levels and plasminogen activator inhibitor-1 activity. In vitro evidence with vascular smooth muscle cells (VSMCs) demonstrated that proliferation and migration were decreased significantly after sitagliptin treatment. In addition, sitagliptin increased caspase-3 activity and decreased monocyte adhesion and NFκB activation in VSMCs. Conclusions: Sitagliptin has protective properties against restenosis after carotid injury and therapeutic implications for treating macrovascular complications of diabetes
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