4075 results for "*geneti*"

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• Identification of responsible genes and development of standardized medicine for familial breast cancer by genetic analysis with NGS technology

  Aims: To clarify risk of germline variants of known causal genes for Hereditary Breast Ovarian Cancer Syndrome in Japan by combinatorial analysis of somatic and germline variants in the breast cancer tissue. Methods: Target caputure analysis by using Illumina HiSeq 2000; the panel genes are 119 genes including 30 HBOC known causal genes. Participants/Materials: 108 whole blood and 124 primary tumor samples from familial breast cancer patients.

  Study JGAS000224

• Chromatin remodeler CHD7 regulates the stem cell identity of human neural progenitors

  Multiple congenital disorders often present complex phenotypes, but how the mutation of individual genetic factors can lead to multiple defects remains poorly understood. In the present study, we used human neuroepithelial (NE) cells and CHARGE patient-derived cells as an in vitro model system to identify the function of chromodomain helicase DNA-binding 7 (CHD7) in NE?neural crest bifurcation, thus revealing an etiological link between the central nervous system (CNS) and craniofacial anomalies observed in CHARGE syndrome. We found that CHD7 is required for epigenetic activation of superenhancers and CNS-specific enhancers, which support the maintenance of the NE and CNS lineage identities. Furthermore, we found that BRN2 and SOX21 are downstream effectors of CHD7, which shapes cellular identities by enhancing a CNS-specific cellular program and indirectly repressing non- CNS-specific cellular programs. Based on our results, CHD7, through its interactions with superenhancer elements, acts as a regulatory hub in the orchestration of the spatiotemporal dynamics of transcription factors to regulate NE and CNS lineage identities.

  Study JGAS000131

• Target resequencing of LQTS-related 100 genes in Japanese patients

  Some of the fatal familial arrhythmias cause sudden death in seemingly healthy individuals. It is not easy to make a pre-symptomatic diagnosis of these diseases using only clinical examinations such as an electrocardiogram. The purpose of this study is to elucidate the cause of lethal arrhythmia and/or the genetic factors that influence its susceptibility, thereby enabling early diagnosis and selection of effective treatment methods, and preventing sudden death. The most important purpose of this study is to identify the sites of genetic abnormalities and disease-related genes in pre-symptomatic cases. If a genetic abnormality is found, it is expected that the functional abnormality can be evaluated and appropriate measures to prevent sudden death can be taken.

  Study JGAS000579

• In vitro reconstitution of epigenetic reprogramming in the human germ line

  Epigenetic reprogramming resets parental epigenetic memories and differentiates primordial germ cells (PGCs) into mitotic pro-spermatogonia or oogonia, ensuring sexually dimorphic germ-cell development for totipotency. In vitro reconstitution of epigenetic reprogramming in humans remains a fundamental challenge. Here, we establish a robust strategy for inducing epigenetic reprogramming and differentiation of pluripotent stem cell (PSC)-derived human PGC-like cells (hPGCLCs) into mitotic pro-spermatogonia or oogonia, coupled with their extensive amplification (~>1010-fold). Strikingly, bone morphogenetic protein (BMP) signalling is a key driver of these processes: BMP-driven hPGCLC differentiation involves an attenuation of the mitogen-activated protein kinase/extracellular-regulated kinase (MAPK/ERK) pathway and both de novo and maintenance DNA methyltransferase (DNMT) activities, likely promoting replication-coupled, passive DNA demethylation. On the other hand, hPGCLCs deficient in tens-eleven translocation (TET) 1, an active DNA demethylase abundant in human germ cells, differentiate into extraembryonic cells, including amnion, with de-repression of key genes bearing bivalent promoters; these cells fail to fully activate genes vital for spermatogenesis and oogenesis, with their promoters remaining methylated. Our study elucidates the framework of epigenetic reprogramming in humans, making a fundamental advance in human biology, and through the generation of abundant mitotic pro-spermatogonia and oogonia-like cells, represents a milestone for human in vitro gametogenesis (IVG) research and its potential translation into reproductive medicine.

  Study JGAS000690

• Discovery of genetic factors associated with thiopurine-induced severe adverse events

  Despite NUDT15 variants showing significant association with thiopurine-induced adverse events (AEs) in Asians, it remains unclear whether additional genetic variants should be tested to predict AEs. To clarify it, we performed a genome-wide association study to discover additional variants associated with thiopurine-induced severe AEs, alopecia and leukopenia. GWASs of these AEs were performed with 1221 Japanese patients with inflammatory bowel disease using population-optimized genotyping array and imputation.

  Study JGAS000661

• Na?ve Treg-specific genomic DNA hypomethylation for autoimmune disease susceptibility

  Naturally occurring regulatory T (Treg) cells, which are specifically expressing the transcription factor FOXP3, CD25 and CTLA-4, are indispensable for the maintenance of immunological self-tolerance and homeostasis. Mutations of the FOXP3, CD25 and CTLA4 genes compromise the function of natural FOXP3+CD25+CD4+ Treg cells and cause severe autoimmune diseases showing Mendelian inheritance. Also, altered Treg-specific epigenetic changes, such as DNA hypomethylation and enhancer activation, impair the expression of these molecules in developing Treg cells, causing autoimmune diseases. It is obscure, however, whether Treg cells significantly contribute to the development of polygenic common autoimmune diseases (such as type 1 diabetes and rheumatoid arthritis), which afflict ~10% of the population. Recent genome-wide association study (GWAS) of common autoimmune diseases has revealed many autoimmune disease-associated single nucleotide polymorphisms (SNPs) in enhancer regions of immune cells, for example, in non-coding regions of T cell activation-associated genes such as CD25 and CTLA4. These findings, especially the involvement of common T-cell genes in the functions of both Treg cells and effector T cells, prompt one to ask whether autoimmune disease-associated causative SNPs impact on the functions of either disease-causing effector T cells or disease-suppressing Treg cells. Here, we have explored epigenetic profiles of human Treg and conventional T (Tconv) cells in na?ve or activated states, and found that autoimmune disease-associated SNPs are predominantly enriched in Treg-specific CpG demethylated regions (Treg-DRs), which were mostly included in Treg-specific super-enhancers. Treg-DRs are developmentally established in na?ve Treg cells before antigenic stimulation, distinct from activation-induced CpG hypomethylation in Treg or Tconv cells, and highly associated with Treg cell-specific transcriptional and epigenetic changes. Taken together, genetic variants affecting endogenous development of natural Treg cells and their Treg-intrinsic functions are causative of common autoimmune diseases, indicating natural Treg cells as a key target for their treatment and prevention.

  Study JGAS000145

• Development of Novel Synovial Sarcoma Organoids Models for Drug Discovery

  Although synovial sarcoma has been studied using established cell lines and mouse models, effective treatments remain limited. We treated five patients with synovial sarcoma between 2022 and 2023 and established organoid cultures from resected tumor specimens using a modified air-liquid interface method. After serial passaging, organoids were successfully xenografted into NOD-scid IL2Rgnull (NSG) mice in three cases. The established organoids retained SS18-SSX fusion transcripts and demonstrated histological and genetic similarities to the original tumors. These organoid models provide a reliable platform for studying synovial sarcoma biology and hold promise for the development of novel therapeutic strategies.

  Study JGAS000806

• C-MACH reduced-representation bisulfite sequencing (RRBS)

  Umbilical cord blood (CB) has been commonly used as an epigenetic surrogate of fetuses. Here, we propose umbilical cord tissue (UC) as an alternative surrogate for epigenetic studies on fetuses. To explore the feasibility to examine UC epigenome by deep sequencing, we determined CpG methylation profiles of human postnatal UC by reduced representation bisulfite sequencing. We compared DNA methylomes between UC and CB. To investigate the effect of folate during pregnancy on fetal DNA methylation, we compared fetal UC DNA methylation between low and high levels of maternal plasma folate. Our study suggests that UC is useful as an alternative surrogate for studying environmental effects on DNA methylation in human fetuses, compensating CB by providing additional information about epigenetic regulation of genes.

  Study JGAS000171

• Effective screening strategy for deafness using a new-genetation sequencing platform: a consecutive analysis

  The diagnosis of the genetic etiology of deafness contributes to the clinical management of patients. We performed the following four genetic tests in three stages for 52 consecutive deafness subjects in one facility. We used the Invade assay and Sanger sequencing for the GJB2 gene or SLC26A4 gene in the first stage test, TaqMan genotyping assay in second stage test, and targeted exon sequencing using the massively parallel DNA sequencing in third stage test. Overall, we identified the genetic cause in 40% (21/52) of patients. The diagnostic rates of the first-, second- and third-stage genetic testing were 17%(9/52), 9%(4/43) and 21% (8/39), respectively. The combination approach using these genetic tests appears to be useful as a diagnostic tool for deafness patients. We recommended that genetic testing for the screening of common mutations in deafness genes using the Invader assay or TaqMan genotyping assay be performed as the initial evaluation. For the remaining undiagnosed cases, targeted exon sequencing using MPS is clinically and economically beneficial. This data set was MPS reads data (fastq) for 39 sensorineural hearing loss patients.

  Study JGAS000032

• CRISPR-screening identifies mechanisms of resistance to KRASG12C and SHP2 inhibitor combinations in non-small cell lung cancer

  Although KRASG12C inhibitors show clinical activity in patients with KRAS G12C mutated NSCLC and other solid tumor malignancies, response is limited by multiple mechanisms of resistance. The KRASG12C inhibitor JDQ443 shows enhanced preclinical antitumor activity combined with the SHP2 inhibitor TNO155, and the combination is currently under clinical evaluation. To identify rational combination strategies that could help overcome or prevent some types of resistance, we evaluated the duration of tumor responses to JDQ443 �� TNO155, alone or combined with the PI3K�� inhibitor alpelisib and/or the CDK4/6 inhibitor ribociclib, in xenograft models derived from a KRASG12C-mutant NSCLC line and investigated the genetic mechanisms associated with loss of response to combined KRASG12C/SHP2 inhibition.

  Study JGAS000643