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- Ambroise, Gorbatchev, et al.
(författare)
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Systematic analysis reveals a functional role for STAMBPL1 in the epithelial-mesenchymal transition process across multiple carcinomas
- 2020
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Ingår i: British Journal of Cancer. - : SPRINGERNATURE. - 0007-0920 .- 1532-1827. ; 123:7, s. 1164-1177
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Tidskriftsartikel (refereegranskat)abstract
- Background Deubiquitinating enzymes (DUBs) are linked to cancer progression and dissemination, yet less is known about their regulation and impact on epithelial-mesenchymal transition (EMT). Methods An integrative translational approach combining systematic computational analyses of The Cancer Genome Atlas cancer cohorts with CRISPR genetics, biochemistry and immunohistochemistry methodologies to identify and assess the role of human DUBs in EMT. Results We identify a previously undiscovered biological function of STAM-binding protein like 1 (STAMBPL1) deubiquitinase in the EMT process in lung and breast carcinomas. We show that STAMBPL1 expression can be regulated by mutant p53 and that its catalytic activity is required to affect the transcription factor SNAI1. Accordingly, genetic depletion and CRISPR-mediated gene knockout of STAMBPL1 leads to marked recovery of epithelial markers, SNAI1 destabilisation and impaired migratory capacity of cancer cells. Reversely, STAMBPL1 expression reprogrammes cells towards a mesenchymal phenotype. A significant STAMBPL1-SNAI1 co-signature was observed across multiple tumour types. Importantly, STAMBPL1 is highly expressed in metastatic tissues compared to matched primary tumour of the same lung cancer patient and its expression predicts poor prognosis. Conclusions Our study provides a novel concept of oncogenic regulation of a DUB and presents a new role and predictive value of STAMBPL1 in the EMT process across multiple carcinomas.
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| 2. |
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| 3. |
- Crona, Filip, et al.
(författare)
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The Brakeless co-regulator can directly activate and repress transcription in early Drosophila embryos
- 2015
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Ingår i: Developmental Biology. - : Elsevier BV. - 0012-1606 .- 1095-564X. ; 407:1, s. 173-181
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Tidskriftsartikel (refereegranskat)abstract
- The Brakeless protein performs many important functions during Drosophila development, but how it controls gene expression is poorly understood. We previously showed that Brakeless can function as a transcriptional co-repressor. In this work, we perform transcriptional profiling of brakeless mutant embryos. Unexpectedly, the majority of affected genes are down-regulated in brakeless mutants. We demonstrate that genomic regions in close proximity to some of these genes are occupied by Brakeless, that over-expression of Brakeless causes a reciprocal effect on expression of these genes, and that Brakeless remains an activator of the genes upon fusion to an activation domain. Together, our results show that Brakeless can both repress and activate gene expression. A yeast two-hybrid screen identified the Mediator complex subunit Med19 as interacting with an evolutionarily conserved part of Brakeless. Both down- and up-regulated Brakeless target genes are also affected in Med19-depleted embryos, but only down-regulated targets are influenced in embryos depleted of both Brakeless and Med19. Our data provide support for a Brakeless activator function that regulates transcription by interacting with Med19. We conclude that the transcriptional co-regulator Brakeless can either activate or repress transcription depending on context.
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| 4. |
- Imreh, Gabriela, et al.
(författare)
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Chromosomal breaks during mitotic catastrophe trigger gamma H2AX-ATM-p53-mediated apoptosis
- 2011
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Ingår i: Journal of Cell Science. - : The Company of Biologists. - 0021-9533 .- 1477-9137. ; 124:17, s. 2951-2963
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Tidskriftsartikel (refereegranskat)abstract
- Although the cause and outcome of mitotic catastrophe (MC) has been thoroughly investigated, precisely how the ensuing lethality is regulated during or following this process and what signals are involved remain unknown. Moreover, the mechanism of the decision of cell death modalities following MC is still not well characterised. We demonstrate here a crucial role of the gamma H2AX-ATM-p53 pathway in the regulation of the apoptotic outcome of MC resulting from cells entering mitosis with damaged DNA. In addition to p53 deficiency, the depletion of ATM (ataxia telangiectasia mutated), but not ATR ( ataxia telangiectasia and Rad3-related protein), protected against apoptosis and shifted cell death towards necrosis. Activation of this pathway is triggered by the augmented chromosomal damage acquired during anaphase in doxorubicin-treated cells lacking 4-3-3 sigma (also known as epithelial cell marker protein-1 or stratifin). Moreover, cells that enter mitosis with damaged DNA encounter segregation problems because of their abnormal chromosomes, leading to defects in mitotic exit, and they therefore accumulate in G1 phase. These multi- or micronucleated cells are prevented from cycling again in a p53- and p21-dependent manner, and subsequently die. Because increased chromosomal damage resulting in extensive H2AX phosphorylation appears to be a direct cause of catastrophic mitosis, our results describe a mechanism that involves generation of additional DNA damage during MC to eliminate chromosomally unstable cells.
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