The argonaute protein family provides central components for RNA interference (RNAi) and related phenomena in a wide variety of organisms. Here, we isolated, from a Bombyx mori cell, a cDNA clone named BmAGO2, which is homologous to Drosophila ARGONAUTE2, the gene encoding a repressive factor for the recombination repair of extrachromosomal double-strand breaks (DSBs). RNAi-mediated silencing of the BmAGO2 sequence markedly increased homologous recombination (HR) repair of DSBs in episomal DNA, but had no effect on that in chromosomes. Moreover, we found that RNAi for BmAGO2 enhanced the integration of linearized DNA into a silkworm chromosome via HR. These results suggested that BmAgo2 protein plays an indispensable role in the repression of extrachromosomal DSB repair.
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http://dx.doi.org/10.1093/nar/gkj507 | DOI Listing |
Nature
January 2025
Stanford Cancer Institute, School of Medicine, Stanford University, Stanford, CA, USA.
Breast cancer is a highly heterogeneous disease whose prognosis and treatment as defined by the expression of three receptors-oestrogen receptor (ER), progesterone receptor and human epidermal growth factor receptor 2 (HER2; encoded by ERBB2)-is insufficient to capture the full spectrum of clinical outcomes and therapeutic vulnerabilities. Previously, we demonstrated that transcriptional and genomic profiles define eleven integrative subtypes with distinct clinical outcomes, including four ER subtypes with increased risk of relapse decades after diagnosis. Here, to determine whether these subtypes reflect distinct evolutionary histories, interactions with the immune system and pathway dependencies, we established a meta-cohort of 1,828 breast tumours spanning pre-invasive, primary invasive and metastatic disease with whole-genome and transcriptome sequencing.
View Article and Find Full Text PDFSuccessful transgenesis in model organisms has dramatically helped us understand gene function, regulation, genetic networks, and potential applications. Here, we introduce the universal single-copy knock-in system (Universal SKI System or U-SKI), designed for inserting any transgene by CRISPR/Cas9 in the genome. The Universal SKI System takes advantage of a plasmid (pSKI), which can also be used for extrachromosomal arrays, to facilitate the insertion of a transgene at specific safe harbor loci on each autosomal chromosome.
View Article and Find Full Text PDFIntractable Rare Dis Res
November 2024
Department of Neurosurgery, Haikou Affiliated Hospital of Central South University Xiangya School of Medicine, Haikou, Hainan, China.
Extrachromosomal DNA (ecDNA) refers to a class of circular, non-chromosomal DNA that has recently gained widespread attention due to its potential role in aging and neurodegenerative diseases. The generation of ecDNA is closely associated with processes such as double-strand breaks, micronuclei formation, and the breakage-fusion-bridge (BFB) cycle, all of which are integral to regulation of gene expression, genetic stability, and clonal evolution. In neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease, the aberrant formation of ecDNA is closely linked to defects in DNA repair, alterations in synaptic plasticity, and neuronal dysfunction.
View Article and Find Full Text PDFBMC Cancer
November 2024
Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, P. R. China.
Nature
November 2024
Center for Personal Dynamic Regulomes, Stanford University, Stanford, CA, USA.
Extrachromosomal DNA (ecDNA) presents a major challenge for cancer patients. ecDNA renders tumours treatment resistant by facilitating massive oncogene transcription and rapid genome evolution, contributing to poor patient survival. At present, there are no ecDNA-specific treatments.
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