The E2F1 transcription factor can promote proliferation or apoptosis when activated, and is a key downstream target of the retinoblastoma tumour suppressor protein (pRB). Here we show that E2F1 is a potent and specific inhibitor of beta-catenin/T-cell factor (TCF)-dependent transcription, and that this function contributes to E2F1-induced apoptosis. E2F1 deregulation suppresses beta-catenin activity in an adenomatous polyposis coli (APC)/glycogen synthase kinase-3 (GSK3)-independent manner, reducing the expression of key beta-catenin targets including c-MYC. This interaction explains why colorectal tumours, which depend on beta-catenin transcription for their abnormal proliferation, keep RB1 intact. Remarkably, E2F1 activity is also repressed by cyclin-dependent kinase-8 (CDK8), a colorectal oncoprotein. Elevated levels of CDK8 protect beta-catenin/TCF-dependent transcription from inhibition by E2F1. Thus, by retaining RB1 and amplifying CDK8, colorectal tumour cells select conditions that collectively suppress E2F1 and enhance the activity of beta-catenin.
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http://dx.doi.org/10.1038/nature07310 | DOI Listing |
Cell Mol Biol Lett
January 2025
Department of Orthopaedics, Peking University Third Hospital, Peking University, No.49 NorthGarden Road, Haidian District, Beijing, 100191, Beijing, China.
Background: Epigenetic modifications have been proved to play important roles in the spinal degenerative diseases. As a type of noncoding RNA, the microRNA (miRNA) is a vital class of regulatory factor in the epigenetic modifications, while the role of miRNAs in the regulation of epigenetic modifications in ligamentum flavum hypertrophy (LFH) has not been fully investigated.
Methods: The miRNA sequencing analysis was used to explore the change of miRNA expression during the fibrosis of ligamentum flavum (LF) cells caused by the TGF-β1 (10 ng/ml).
J Stroke Cerebrovasc Dis
January 2025
Department of Gerontology, The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, 646000, China. Electronic address:
Objective: Hirudin has shown potential in promoting angiogenesis and providing neuroprotection in ischemic stroke; however, its therapeutic role in promoting cerebrovascular angiogenesis remains unclear. In this study, we aimed to investigate whether hirudin exerts neuroprotective effects by promoting angiogenesis through the regulation of the Wnt/β-catenin signaling pathway.
Methods: An in vitro model of glucose and oxygen deprivation/reperfusion (OGD/R) was established using rat brain microvascular endothelial cells (BMECs).
Elife
January 2025
Departments of Molecular & Cellular Physiology and Structural Biology, Stanford University School of Medicine, Stanford, United States.
Wnt/β-catenin signaling directs animal development and tissue renewal in a tightly controlled, cell- and tissue-specific manner. In the mammalian central nervous system, the atypical ligand Norrin controls angiogenesis and maintenance of the blood-brain barrier and blood-retina barrier through the Wnt/β-catenin pathway. Like Wnt, Norrin activates signaling by binding and heterodimerizing the receptors Frizzled (Fzd) and low-density lipoprotein receptor-related protein 5 or 6 (LRP5/6), leading to membrane recruitment of the intracellular transducer Dishevelled (Dvl) and ultimately stabilizing the transcriptional coactivator β-catenin.
View Article and Find Full Text PDFInt J Med Sci
January 2025
Department of Emergency Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
Marburg virus (MARV) disease (MVD) is an uncommon yet serious viral hemorrhagic fever that impacts humans and non-human primates. In humans, infection by the MARV is marked by rapid onset, high transmissibility, and elevated mortality rates, presenting considerable obstacles to the development of vaccines and treatments. Bats, particularly , are suspected to be natural hosts of MARV.
View Article and Find Full Text PDFNeoplasia
December 2024
Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, Liaoning 110016, PR China. Electronic address:
Pancreatic ductal adenocarcinoma (PDAC) is characterized by its aggressive nature and dismal prognosis, largely attributed to its unique tumor microenvironment. However, the molecular mechanisms by which tumor-associated macrophages (TAMs) promote PDAC progression, particularly the role of β-catenin signaling in regulating TAM phenotype and function, remain incompletely understood. Initially, we performed comprehensive analyses of RNA-seq and single-cell RNA-seq (scRNA-seq) datasets to investigate OSM and LOXL2 expression patterns in PDAC.
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