Glioblastoma multiforme is the most common type of primary malignant brain tumor and may arise from a cell with neural stem-like properties. Deregulation of the retinoblastoma, phosphoinositide-3 kinase (PI3K), and p53 pathways are molecular hallmarks of this disease. Recent work has shown that p53(-/-)Pten(-/-) mice form gliomas in a c-Myc-dependent manner. To explore the role of the INK4A/ARF locus and Pten deletions in gliomagenesis, we generated Pten(-/-)Ink4a/Arf(-/-) mouse neural stem cells (mNSC) and such cells were highly proliferative, self-renewing, relatively refractory to differentiation, and induced both low- and high-grade glioma formation in vivo. In contrast to p53(-/-) Pten(-/-) mNSCs, however, Pten(-/-)Ink4a/Arf(-/-) mNSCs do not express appreciable levels of c-Myc in vitro, although glioma stem cells derived from thesecells did. Sequencing of Pten(-/-)Ink4a/Arf(-/-) mNSC-derived tumors revealed spontaneous mutations in Tp53 in vivo with subsequent downregulation of Fbxw7. Expression of p53 mutants in Pten(-/-)Ink4a/Arf(-/-) mNSC or knockdown of Fbxw7 resulted in reexpression of c-Myc with enhanced Pten(-/-)Ink4a/Arf(-/-) mNSC tumorigenecity. We propose that p53 mutations contribute to gliomagenesis by both allowing the overexpression of c-Myc through downregulation of Fbxw7 and by protecting against c-Myc-induced apoptosis.
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http://dx.doi.org/10.1158/0008-5472.CAN-12-2594 | DOI Listing |
Tissue Eng Part C Methods
January 2025
Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland.
Scaffold-free tissue engineering strategies using cellular aggregates, microtissues, or organoids as "biological building blocks" could potentially be used for the engineering of scaled-up articular cartilage or endochondral bone-forming grafts. Such approaches require large numbers of cells; however, little is known about how different chondrogenic growth factor stimulation regimes during cellular expansion and differentiation influence the capacity of cellular aggregates or microtissues to fuse and generate hyaline cartilage. In this study, human bone marrow mesenchymal stem/stromal cells (MSCs) were additionally stimulated with bone morphogenetic protein 2 (BMP-2) and/or transforming growth factor (TGF)-β1 during both monolayer expansion and subsequent chondrogenic differentiation in a microtissue format.
View Article and Find Full Text PDFSci Adv
January 2025
Istituto per l'Endocrinologia e l'Oncologia Sperimentale "G. Salvatore", IEOS-CNR, Napoli, Italy.
CD4FOXP3 regulatory T cells (T) suppress immune responses to tumors, and their accumulation in the tumor microenvironment (TME) correlates with poor clinical outcome in several cancers, including breast cancer (BC). However, the properties of intratumoral T remain largely unknown. Here, we found that a functionally distinct subpopulation of T, expressing the FOXP3 Exon2 splicing variants, is prominent in patients with hormone receptor-positive BC with poor prognosis.
View Article and Find Full Text PDFElife
January 2025
Center for Spatial and Functional Genomics, The Children's Hospital of Philadelphia, Philadelphia, United States.
The prevalence of childhood obesity is increasing worldwide, along with the associated common comorbidities of type 2 diabetes and cardiovascular disease in later life. Motivated by evidence for a strong genetic component, our prior genome-wide association study (GWAS) efforts for childhood obesity revealed 19 independent signals for the trait; however, the mechanism of action of these loci remains to be elucidated. To molecularly characterize these childhood obesity loci, we sought to determine the underlying causal variants and the corresponding effector genes within diverse cellular contexts.
View Article and Find Full Text PDFStem Cells
January 2025
Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX13QX, UK.
The large majority of Alzheimer's disease (AD) cases are sporadic with unknown genetic causes. In contrast, only a small percentage of AD cases are familial, with known genetic causes. Paradoxically, there are only few validated mouse models of sporadic AD but many of familial AD.
View Article and Find Full Text PDFSTAR Protoc
January 2025
Laboratory of Molecular Physiology of Bone, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic. Electronic address:
Bone marrow stromal cells (BMSCs) serve as a valuable reservoir of multipotent stem cells important in the regulation of bone homeostasis and energy metabolism. Here, we present a protocol for isolating human BMSCs (hBMSCs) and characterizing their cellular metabolism related to hBMSC functional properties. We describe steps for bioenergetics, cell senescence, and production of reactive oxygen species (ROS), together with description of the data analysis.
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