Ontology highlight
ABSTRACT:
PROVIDER: PRJNA356424 | ENA |
REPOSITORIES: ENA
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Project description:Aneuploidy results in decreased cellular fitness in many different species and model systems. However, aneuploidy is commonly found in cancer cells and often correlates with aggressive growth and poor prognosis, suggesting that the impact of aneuploidy on cellular fitness is context dependent. The BRG1 (SMARCA4) subunit of the SWI/SNF chromatin remodelling complex is a tumour suppressor that is frequently lost in cancer cells. Here, we used a chromosomally stable cell line to test the effect of BRG1 loss on the evolution of aneuploidy. We find that BRG1 deletion leads to an initial loss of fitness in this cell line that improves over time. The improved fitness correlates with a gain of extra copies of chromosome 18. Notably, changes in pathways that are known to promote tolerance to aneuploidy are evident immediately upon loss of BRG1, providing an environment where karyotype changes associated with a fitness advantage can be explored. At least in some genetic backgrounds, therefore, loss of the SWI/SNF complex can contribute to tumourigenesis through tolerance of aneuploidy.
2022-03-23 | PXD014954 | Pride
Project description:We investigated how yeast cells deficient in performing homologous recombination-mediated DNA repair due to a deletion of the critical RAD52 gene respond to irreparable DNA damage inflicted by genotoxic treatment commonly applied in cancer therapy (camptothecin and irradiation). We found that upon persistence of irreparable DNA damage, yeast rad52 mutants readily undergo checkpoint adaptation accompanied by the acquisition of resistance to further genotoxic insults as well as the development of aneuploidy. Together, our findings can be used to elucidate how repair-defective cancer cells can become treatment-resistant thereby providing a way to target these resistant cell clones by tackling their aneuploidy-associated phenotypes. To investigate these characteristics commonly present in aneuploid cells in our experimental set-up, we treated yeast cells with genotoxic agents and performed whole genome sequencing. We could identify frequent whole chromosome loss events manifesting in a sensitivity of cells to aneuploidy-targeting agents.
2019-10-22 | E-MTAB-7380 | biostudies-arrayexpress
Project description:Aneuploidy is a frequent feature of human tumors. Germline mutations leading to aneuploidy are very rare in humans, and their tumor-promoting properties are mostly unknown at the molecular level. We report here novel germline biallelic mutations in MAD1L1, the gene encoding the Spindle Assembly Checkpoint (SAC) protein MAD1, in a 36-year-old female with a dozen of neoplasias, including five malignant tumors. Functional studies in peripheral blood cells demonstrated lack of full-length protein and deficient SAC response, resulting in ~30-40% of aneuploid cells as detected by cytogenetic and single-cell (sc) DNA analysis. scRNA-seq analysis of proband blood cells identified mitochondrial stress accompanied by systemic inflammation with enhanced interferon and NFkB signaling. The inference of chromosomal aberrations from scRNA-seq analysis detected inflammatory signals both in aneuploid and euploid cells, suggesting a non-cell autonomous response to aneuploidy. In addition to random aneuploidies, MAD1L1 mutations resulted in specific clonal expansions of T-cells with chromosome 18 gains and enhanced cytotoxic profile, as well as intermediate B-cells with chromosome 12 gains and transcriptomic signatures characteristic of chronic lymphocytic leukemia cells. These data point to MAD1L1 mutations as the cause of a new variant of mosaic variegated aneuploidy syndrome (MVA) with systemic inflammation and unprecedented tumor susceptibility.
2023-03-11 | PXD035765 | Pride
Project description:STAG2 is a novel UBC tumor suppressor acting through mechanisms that are different from its role to prevent aneuploidy
2013-10-24 | GSE51640 | GEO
Project description:STAG2 is a novel UBC tumor suppressor acting through mechanisms that are different from its role to prevent aneuploidy
2013-10-24 | GSE51589 | GEO
Project description:Two major genetic pathways leading to colorectal carcinoma can well be distinguished; the ‘suppressor pathway’, which is characterized by inactivation of tumor-suppressor genes and the ‘mutator pathway’, which is characterized by microsatellite instability. The purpose of this study is to explore a third putative pathway; microsatellite and chromosome stable colorectal cancer where an alternative cancer-causative mechanism might play a role.
| 2021019 | ecrin-mdr-crc
Project description:STAG2 is a novel UBC tumor suppressor acting through mechanisms that are different from its role to prevent aneuploidy Gene copy number analyses of STAG2 in urinary bladder tumors. R values were extracted from beadstudio and normalised using the pounds method. Log R Ratios were calculated using an average value of R from 200 cases and controls from the Epicuro study. WaviCGH was used to generate copy number calls and log R ratios in the region of STAG2 on the X chromosome were also visualised manually to determine STAG2 loss.
2013-10-24 | E-GEOD-51589 | biostudies-arrayexpress
Project description:STAG2 is a novel UBC tumor suppressor acting through mechanisms that are different from its role to prevent aneuploidy Gene copy number analyses of STAG2 in urinary bladder tumors. R values were extracted from beadstudio and normalised using the pounds method. Log R Ratios were calculated using an average value of R from 200 cases and controls from the Epicuro study. WaviCGH was used to generate copy number calls and log R ratios in the region of STAG2 on the X chromosome were also visualised manually to determine STAG2 loss.
2013-10-24 | E-GEOD-51640 | biostudies-arrayexpress
Project description:Here, in order to investigate the regulation mechanism of the MSL complex in unbalanced genomes and its further functions involved in sexual dimorphism, we over-expressed MSL2 in autosomal aneuploidy (XX, AAA) and sex chromosome aneuploidy (XXX, AA), and analyzed the different transcriptomes.
2021-10-13 | GSE162951 | GEO
Project description:Chromosomal instability (CIN), defined as an increased occurrence of chromosome segregation errors during cell division, is a prominent form of genomic instability (Bakhoum and Avi Landau, 2017). It is the major cause of aneuploidy, an imbalanced complement of whole chromosomes or chromosome arms, which is the most prevalent genetic alteration in human cancers (Vasudevan et al., 2021; Santaguida and Amon, 2015). Importantly, aneuploidy is commonly associated with ongoing CIN through consecutive cell divisions (Shelzer et al. 2011; Passerini et al., 2016), resulting in intratumor genetic heterogeneity, a central driver of cancer evolution and therapeutic resistance (Sansregret et al., 2018; Ben-David and Amon, 2019). Indeed, aneuploidy has been shown to act both as a tumor suppressor and as a tumor initiator (Weaver et al., 2007; Silk et al., 2013; Vasudevan et al., 2020), most likely depending on the specific chromosomes that are gained or lost (Ben-David et al., 2011; Sack et al., 2018; Adell et al., 2023). Despite the ubiquitous presence of CIN in several aneuploid cancer types and its clinical relevance, its presence in B-cell acute lymphoblastic leukemia (B-ALL) remains largely unexplored owing to the impaired proliferation of leukemic cells in vitro and the lack of reliable experimental models to comprehensively assess chromosome segregation in vivo. B-ALL is the most frequent childhood cancer, with 75% of cases occurring in children under 6 years of age, and it is characterized by the accumulation of highly proliferative immature B-cell precursors in the bone marrow (BM) (Hunger and Mullighan, 2015). The presence of CIN and its contribution to aneuploid cB-ALL progression is largely unknown due to the lack of preclinical models to study actively dividing cells. Accordingly, studies of CIN in cB-ALL are limited to the characterization of chromosomal copy-number heterogeneity (chr-CNH) in primary cB-ALL samples, but there is controversy over its presence due to the different techniques used to assess karyotype variability (Raimondi et al., 1996; Talamo et al., 2010; Alpar et al., 2014; Heerema et al.; 2007; Ramos-Muntada et al., 2022). Here, we explored the presence and the levels of CIN in different clinically-relevant aneuploid subtypes of cB-ALL using single-cell whole-genome sequencing (WGS) of primary samples to reliably assess chr-CNH, and by generating a large cohort of PDX models from primary cB-ALL samples (cB-ALL-PDX). Our results in cB-ALL-PDX models revealed variable levels of CIN in aneuploid cB-ALL subtypes, which significantly correlate with intraclonal karyotype heterogeneity and with disease progression. Additionally, mass-spectrometry analyses of cB-ALL-PDX samples revealed a CIN “signature” enriched in mitosis and chromosome segregation regulatory pathways. We speculate that this signature identifies adaptive mechanisms to ongoing CIN in aneuploid cB-ALL cells, which displayed a transcriptional signature characterized by an impaired mitotic spindle as observed by RNA-sequencing (RNA-Seq) analyses of a large cohort of primary cB-ALL patient samples. Our work might help to improve stratification of patients with cB-ALL with different levels of CIN who could benefit in the future from new therapeutic approaches aiming to target ongoing CIN.
2023-09-15 | PXD042785 | Pride