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  1. Article ; Online: CtIP-dependent nascent RNA expression flanking DNA breaks guides the choice of DNA repair pathway.

    Gómez-Cabello, Daniel / Pappas, George / Aguilar-Morante, Diana / Dinant, Christoffel / Bartek, Jiri

    Nature communications

    2022  Volume 13, Issue 1, Page(s) 5303

    Abstract: The RNA world is changing our views about sensing and resolution of DNA damage. Here, we develop single-molecule DNA/RNA analysis approaches to visualize how nascent RNA facilitates the repair of DNA double-strand breaks (DSBs). RNA polymerase II (RNAPII) ...

    Abstract The RNA world is changing our views about sensing and resolution of DNA damage. Here, we develop single-molecule DNA/RNA analysis approaches to visualize how nascent RNA facilitates the repair of DNA double-strand breaks (DSBs). RNA polymerase II (RNAPII) is crucial for DSB resolution in human cells. DSB-flanking, RNAPII-generated nascent RNA forms RNA:DNA hybrids, guiding the upstream DNA repair steps towards favouring the error-free Homologous Recombination (HR) pathway over Non-Homologous End Joining. Specific RNAPII inhibitor, THZ1, impairs recruitment of essential HR proteins to DSBs, implicating nascent RNA in DNA end resection, initiation and execution of HR repair. We further propose that resection factor CtIP interacts with and helps re-activate RNAPII when paused by the RNA:DNA hybrids, collectively promoting faithful repair of chromosome breaks to maintain genomic integrity.
    MeSH term(s) DNA Breaks, Double-Stranded ; DNA End-Joining Repair ; DNA Repair ; Humans ; RNA/genetics ; RNA Polymerase II ; Recombinational DNA Repair
    Chemical Substances RNA (63231-63-0) ; RNA Polymerase II (EC 2.7.7.-)
    Language English
    Publishing date 2022-09-09
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2553671-0
    ISSN 2041-1723 ; 2041-1723
    ISSN (online) 2041-1723
    ISSN 2041-1723
    DOI 10.1038/s41467-022-33027-z
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Ursolic Acid Impairs Cellular Lipid Homeostasis and Lysosomal Membrane Integrity in Breast Carcinoma Cells.

    Fogde, Ditte L / Xavier, Cristina P R / Balnytė, Kristina / Holland, Lya K K / Stahl-Meyer, Kamilla / Dinant, Christoffel / Corcelle-Termeau, Elisabeth / Pereira-Wilson, Cristina / Maeda, Kenji / Jäättelä, Marja

    Cells

    2022  Volume 11, Issue 24

    Abstract: Cancer is one of the leading causes of death worldwide, thus the search for new cancer therapies is of utmost importance. Ursolic acid is a naturally occurring pentacyclic triterpene with a wide range of pharmacological activities including anti- ... ...

    Abstract Cancer is one of the leading causes of death worldwide, thus the search for new cancer therapies is of utmost importance. Ursolic acid is a naturally occurring pentacyclic triterpene with a wide range of pharmacological activities including anti-inflammatory and anti-neoplastic effects. The latter has been assigned to its ability to promote apoptosis and inhibit cancer cell proliferation by poorly defined mechanisms. In this report, we identify lysosomes as the essential targets of the anti-cancer activity of ursolic acid. The treatment of MCF7 breast cancer cells with ursolic acid elevates lysosomal pH, alters the cellular lipid profile, and causes lysosomal membrane permeabilization and leakage of lysosomal enzymes into the cytosol. Lysosomal membrane permeabilization precedes the essential hallmarks of apoptosis placing it as an initial event in the cascade of effects induced by ursolic acid. The disruption of the lysosomal function impairs the autophagic pathway and likely partakes in the mechanism by which ursolic acid kills cancer cells. Furthermore, we find that combining treatment with ursolic acid and cationic amphiphilic drugs can significantly enhance the degree of lysosomal membrane permeabilization and cell death in breast cancer cells.
    MeSH term(s) Humans ; Female ; Lysosomes/metabolism ; Homeostasis ; Breast Neoplasms/drug therapy ; Breast Neoplasms/metabolism ; Lipids/pharmacology ; Ursolic Acid
    Chemical Substances Lipids
    Language English
    Publishing date 2022-12-16
    Publishing country Switzerland
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2661518-6
    ISSN 2073-4409 ; 2073-4409
    ISSN (online) 2073-4409
    ISSN 2073-4409
    DOI 10.3390/cells11244079
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Identification of lysosome-targeting drugs with anti-inflammatory activity as potential invasion inhibitors of treatment resistant HER2 positive cancers.

    Hansen, Malene Bredahl / Postol, Maria / Tvingsholm, Siri / Nielsen, Inger Ødum / Dietrich, Tiina Naumanen / Puustinen, Pietri / Maeda, Kenji / Dinant, Christoffel / Strauss, Robert / Egan, David / Jäättelä, Marja / Kallunki, Tuula

    Cellular oncology (Dordrecht)

    2021  Volume 44, Issue 4, Page(s) 805–820

    Abstract: Purpose: Most HER2 positive invasive cancers are either intrinsic non-responsive or develop resistance when treated with 1st line HER2 targeting drugs. Both 1st and 2nd line treatments of HER2 positive cancers are aimed at targeting the HER2 receptor ... ...

    Abstract Purpose: Most HER2 positive invasive cancers are either intrinsic non-responsive or develop resistance when treated with 1st line HER2 targeting drugs. Both 1st and 2nd line treatments of HER2 positive cancers are aimed at targeting the HER2 receptor directly, thereby strongly limiting the treatment options of HER2/ErbB2 inhibition resistant invasive cancers.
    Methods: We used phenotypic high throughput microscopy screening to identify efficient inhibitors of ErbB2-induced invasion using 1st line HER2 inhibitor trastuzumab- and pertuzumab-resistant, p95-ErbB2 expressing breast cancer cells in conjunction with the Prestwick Chemical Library®. The screening entailed a drug's ability to inhibit ErbB2-induced, invasion-promoting positioning of lysosomes at the cellular periphery, a phenotype that defines their invasiveness. In addition, we used high throughput microscopy and biochemical assays to assess the effects of the drugs on lysosomal membrane permeabilization (LMP) and autophagy, two features connected to cancer treatment. Using 2nd line HER2 inhibitor lapatinib resistant 3-dimensional model systems, we assessed the effects of the drugs on ErbB2 positive breast cancer spheroids and developed a high-throughput invasion assay for HER2 positive ovarian cancer organoids for further evaluation.
    Results: We identified Auranofin, Colchicine, Monensin, Niclosamide, Podophyllotoxin, Quinacrine and Thiostrepton as efficient inhibitors of invasive growth of 2nd line HER2 inhibitor lapatinib resistant breast cancer spheroids and ovarian cancer organoids. We classified these drugs into four groups based on their ability to target lysosomes by inducing autophagy and/or LMP, i.e., drugs inducing early LMP, early autophagy with late LMP, late LMP, or neither.
    Conclusions: Our results indicate that targetable lysosome-engaging cellular pathways downstream of ErbB2 contribute to invasion. They support lysosomal trafficking as an attractive target for therapy aiming at preventing the spreading of cancer cells. Since these drugs additionally possess anti-inflammatory activities, they could serve as multipurpose drugs simultaneously targeting infection/inflammation and cancer spreading.
    MeSH term(s) Animals ; Anti-Inflammatory Agents/therapeutic use ; Antineoplastic Agents/therapeutic use ; Autophagy/drug effects ; Breast Neoplasms/drug therapy ; Breast Neoplasms/metabolism ; Cell Line, Tumor ; Drug Resistance, Neoplasm/drug effects ; Female ; Humans ; Lapatinib/therapeutic use ; Lysosomes/drug effects ; Lysosomes/metabolism ; MCF-7 Cells ; Mice, Inbred NOD ; Mice, Knockout ; Mice, SCID ; Neoplasm Invasiveness ; Receptor, ErbB-2/metabolism ; Xenograft Model Antitumor Assays/methods ; Mice
    Chemical Substances Anti-Inflammatory Agents ; Antineoplastic Agents ; Lapatinib (0VUA21238F) ; ERBB2 protein, human (EC 2.7.10.1) ; Receptor, ErbB-2 (EC 2.7.10.1)
    Language English
    Publishing date 2021-05-03
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 2595109-9
    ISSN 2211-3436 ; 1875-8606 ; 2211-3428
    ISSN (online) 2211-3436
    ISSN 1875-8606 ; 2211-3428
    DOI 10.1007/s13402-021-00603-2
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: The emerging role of HP1 in the DNA damage response.

    Dinant, Christoffel / Luijsterburg, Martijn S

    Molecular and cellular biology

    2009  Volume 29, Issue 24, Page(s) 6335–6340

    Abstract: Heterochromatin protein 1 (HP1) family members are versatile proteins involved in transcription, chromatin organization, and replication. Recent findings now have implicated HP1 proteins in the DNA damage response as well. Cell-biological approaches ... ...

    Abstract Heterochromatin protein 1 (HP1) family members are versatile proteins involved in transcription, chromatin organization, and replication. Recent findings now have implicated HP1 proteins in the DNA damage response as well. Cell-biological approaches showed that reducing the levels of all three HP1 isoforms enhances DNA repair, possibly due to heterochromatin relaxation. Additionally, HP1 is phosphorylated in response to DNA damage, which was suggested to initiate the DNA damage response. These findings have led to the conclusion that heterochromatic proteins are inhibitory to repair and that their dissociation from heterochromatin may facilitate repair. In contrast with an inhibitory role, a more active role for HP1 in DNA repair also was proposed based on the finding that all HP1 isoforms are recruited to UV-induced lesions, oxidative lesions, and DNA breaks. The loss of HP1 renders nematodes highly sensitive to DNA damage, and mice lacking HP1beta suffer from genomic instability, suggesting that the loss of HP1 is not necessarily beneficial for repair. These findings raise the possibility that HP1 facilitates DNA repair by reorganizing chromatin, which may involve interactions between phosphorylated HP1 and other DNA damage response proteins. Taken together, these studies illustrate an emerging role of HP1 proteins in the response to genotoxic stress.
    MeSH term(s) Animals ; Cell Line ; Chromosomal Proteins, Non-Histone/genetics ; Chromosomal Proteins, Non-Histone/metabolism ; DNA/genetics ; DNA/metabolism ; DNA/radiation effects ; DNA Damage ; DNA Repair ; Heterochromatin/genetics ; Heterochromatin/metabolism ; Histones/metabolism ; Humans ; Models, Genetic ; Oxidative Stress ; Protein Isoforms/genetics ; Protein Isoforms/metabolism ; Ultraviolet Rays
    Chemical Substances Chromosomal Proteins, Non-Histone ; Heterochromatin ; Histones ; Protein Isoforms ; heterochromatin-specific nonhistone chromosomal protein HP-1 (107283-02-3) ; DNA (9007-49-2)
    Language English
    Publishing date 2009-10-05
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 779397-2
    ISSN 1098-5549 ; 0270-7306
    ISSN (online) 1098-5549
    ISSN 0270-7306
    DOI 10.1128/MCB.01048-09
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Histone displacement during nucleotide excision repair.

    Dinant, Christoffel / Bartek, Jiri / Bekker-Jensen, Simon

    International journal of molecular sciences

    2012  Volume 13, Issue 10, Page(s) 13322–13337

    Abstract: Nucleotide excision repair (NER) is an important DNA repair mechanism required for cellular resistance against UV light and toxic chemicals such as those found in tobacco smoke. In living cells, NER efficiently detects and removes DNA lesions within the ... ...

    Abstract Nucleotide excision repair (NER) is an important DNA repair mechanism required for cellular resistance against UV light and toxic chemicals such as those found in tobacco smoke. In living cells, NER efficiently detects and removes DNA lesions within the large nuclear macromolecular complex called chromatin. The condensed nature of chromatin inhibits many DNA metabolizing activities, including NER. In order to promote efficient repair, detection of a lesion not only has to activate the NER pathway but also chromatin remodeling. In general, such remodeling is thought on the one hand to precede NER, thus allowing repair proteins to efficiently access DNA. On the other hand, after completion of the repair, the chromatin must be returned to its previous undamaged state. Chromatin remodeling can refer to three separate but interconnected processes, histone post-translational modifications, insertion of histone variants and histone displacement (including nucleosome sliding). Here we review current knowledge, and speculate about current unknowns, regarding those chromatin remodeling activities that physically displace histones before, during and after NER.
    MeSH term(s) Adenosine Triphosphate/metabolism ; Animals ; Chromatin/metabolism ; Chromatin Assembly and Disassembly ; DNA Damage ; DNA Repair ; Histone Chaperones/metabolism ; Histones/metabolism ; Humans
    Chemical Substances Chromatin ; Histone Chaperones ; Histones ; Adenosine Triphosphate (8L70Q75FXE)
    Language English
    Publishing date 2012-10-17
    Publishing country Switzerland
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 2019364-6
    ISSN 1422-0067 ; 1422-0067 ; 1661-6596
    ISSN (online) 1422-0067
    ISSN 1422-0067 ; 1661-6596
    DOI 10.3390/ijms131013322
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  6. Article ; Online: Histone Displacement during Nucleotide Excision Repair

    Jiri Bartek / Simon Bekker-Jensen / Christoffel Dinant

    International Journal of Molecular Sciences, Vol 13, Iss 10, Pp 13322-

    2012  Volume 13337

    Abstract: Nucleotide excision repair (NER) is an important DNA repair mechanism required for cellular resistance against UV light and toxic chemicals such as those found in tobacco smoke. In living cells, NER efficiently detects and removes DNA lesions within the ... ...

    Abstract Nucleotide excision repair (NER) is an important DNA repair mechanism required for cellular resistance against UV light and toxic chemicals such as those found in tobacco smoke. In living cells, NER efficiently detects and removes DNA lesions within the large nuclear macromolecular complex called chromatin. The condensed nature of chromatin inhibits many DNA metabolizing activities, including NER. In order to promote efficient repair, detection of a lesion not only has to activate the NER pathway but also chromatin remodeling. In general, such remodeling is thought on the one hand to precede NER, thus allowing repair proteins to efficiently access DNA. On the other hand, after completion of the repair, the chromatin must be returned to its previous undamaged state. Chromatin remodeling can refer to three separate but interconnected processes, histone post-translational modifications, insertion of histone variants and histone displacement (including nucleosome sliding). Here we review current knowledge, and speculate about current unknowns, regarding those chromatin remodeling activities that physically displace histones before, during and after NER.
    Keywords nucleotide excision repair ; histone chaperone ; ATP-dependent chromatin remodeling ; histone variants ; Biology (General) ; QH301-705.5 ; Chemistry ; QD1-999
    Subject code 572 ; 500
    Language English
    Publishing date 2012-10-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: SPT6-driven error-free DNA repair safeguards genomic stability of glioblastoma cancer stem-like cells.

    Obara, Elisabeth Anne Adanma / Aguilar-Morante, Diana / Rasmussen, Rikke Darling / Frias, Alex / Vitting-Serup, Kristoffer / Lim, Yi Chieh / Elbæk, Kirstine Juul / Pedersen, Henriette / Vardouli, Lina / Jensen, Kamilla Ellermann / Skjoth-Rasmussen, Jane / Brennum, Jannick / Tuckova, Lucie / Strauss, Robert / Dinant, Christoffel / Bartek, Jiri / Hamerlik, Petra

    Nature communications

    2020  Volume 11, Issue 1, Page(s) 4709

    Abstract: Glioblastoma cancer-stem like cells (GSCs) display marked resistance to ionizing radiation (IR), a standard of care for glioblastoma patients. Mechanisms underpinning radio-resistance of GSCs remain largely unknown. Chromatin state and the accessibility ... ...

    Abstract Glioblastoma cancer-stem like cells (GSCs) display marked resistance to ionizing radiation (IR), a standard of care for glioblastoma patients. Mechanisms underpinning radio-resistance of GSCs remain largely unknown. Chromatin state and the accessibility of DNA lesions to DNA repair machineries are crucial for the maintenance of genomic stability. Understanding the functional impact of chromatin remodeling on DNA repair in GSCs may lay the foundation for advancing the efficacy of radio-sensitizing therapies. Here, we present the results of a high-content siRNA microscopy screen, revealing the transcriptional elongation factor SPT6 to be critical for the genomic stability and self-renewal of GSCs. Mechanistically, SPT6 transcriptionally up-regulates BRCA1 and thereby drives an error-free DNA repair in GSCs. SPT6 loss impairs the self-renewal, genomic stability and tumor initiating capacity of GSCs. Collectively, our results provide mechanistic insights into how SPT6 regulates DNA repair and identify SPT6 as a putative therapeutic target in glioblastoma.
    MeSH term(s) Animals ; Apoptosis ; BRCA1 Protein ; Brain Neoplasms/genetics ; Cell Cycle Checkpoints ; Cell Line, Tumor ; DNA Repair ; Female ; Gene Expression Regulation, Neoplastic ; Gene Knockdown Techniques ; Gene Silencing ; Genomic Instability ; Glioblastoma/genetics ; Glioblastoma/pathology ; HEK293 Cells ; Heterografts ; Humans ; Mice ; Mice, Inbred BALB C ; Neoplastic Stem Cells/pathology ; RNA, Small Interfering/genetics ; Radiation Tolerance ; Radiation, Ionizing ; Transcription Factors/genetics ; Transcription Factors/metabolism ; Transcriptome
    Chemical Substances BRCA1 Protein ; BRCA1 protein, human ; RNA, Small Interfering ; SUPT6H protein, human ; Transcription Factors
    Language English
    Publishing date 2020-09-18
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2553671-0
    ISSN 2041-1723 ; 2041-1723
    ISSN (online) 2041-1723
    ISSN 2041-1723
    DOI 10.1038/s41467-020-18549-8
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: SPT6-driven error-free DNA repair safeguards genomic stability of glioblastoma cancer stem-like cells

    Elisabeth Anne Adanma Obara / Diana Aguilar-Morante / Rikke Darling Rasmussen / Alex Frias / Kristoffer Vitting-Serup / Yi Chieh Lim / Kirstine Juul Elbæk / Henriette Pedersen / Lina Vardouli / Kamilla Ellermann Jensen / Jane Skjoth-Rasmussen / Jannick Brennum / Lucie Tuckova / Robert Strauss / Christoffel Dinant / Jiri Bartek / Petra Hamerlik

    Nature Communications, Vol 11, Iss 1, Pp 1-

    2020  Volume 14

    Abstract: Cancer stem cells can evade treatment. Here, the authors perform an in vitro screen to identify proteins that are involved in protecting glioma cancer stem cells from therapy and find that SPT6 increases BRCA1 expression and drives error-free DNA repair, ...

    Abstract Cancer stem cells can evade treatment. Here, the authors perform an in vitro screen to identify proteins that are involved in protecting glioma cancer stem cells from therapy and find that SPT6 increases BRCA1 expression and drives error-free DNA repair, thereby ensuring the survival of the cells.
    Keywords Science ; Q
    Language English
    Publishing date 2020-09-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article ; Online: Chromatin structure and DNA damage repair.

    Dinant, Christoffel / Houtsmuller, Adriaan B / Vermeulen, Wim

    Epigenetics & chromatin

    2008  Volume 1, Issue 1, Page(s) 9

    Abstract: The integrity of the genome is continuously challenged by both endogenous and exogenous DNA damaging agents. These damaging agents can induce a wide variety of lesions in the DNA, such as double strand breaks, single strand breaks, oxidative lesions and ... ...

    Abstract The integrity of the genome is continuously challenged by both endogenous and exogenous DNA damaging agents. These damaging agents can induce a wide variety of lesions in the DNA, such as double strand breaks, single strand breaks, oxidative lesions and pyrimidine dimers. The cell has evolved intricate DNA damage response mechanisms to counteract the genotoxic effects of these lesions. The two main features of the DNA damage response mechanisms are cell-cycle checkpoint activation and, at the heart of the response, DNA repair. For both damage signalling and repair, chromatin remodelling is most likely a prerequisite. Here, we discuss current knowledge on chromatin remodelling with respect to the cellular response to DNA damage, with emphasis on the response to lesions resolved by nucleotide excision repair. We will discuss the role of histone modifications as well as their displacement or exchange in nucleotide excision repair and make a comparison with their requirement in transcription and double strand break repair.
    Language English
    Publishing date 2008-11-12
    Publishing country England
    Document type Journal Article
    ZDB-ID 2462129-8
    ISSN 1756-8935 ; 1756-8935
    ISSN (online) 1756-8935
    ISSN 1756-8935
    DOI 10.1186/1756-8935-1-9
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  10. Article ; Online: Chromatin structure and DNA damage repair

    Dinant Christoffel / Houtsmuller Adriaan B / Vermeulen Wim

    Epigenetics & Chromatin, Vol 1, Iss 1, p

    2008  Volume 9

    Abstract: Abstract The integrity of the genome is continuously challenged by both endogenous and exogenous DNA damaging agents. These damaging agents can induce a wide variety of lesions in the DNA, such as double strand breaks, single strand breaks, oxidative ... ...

    Abstract Abstract The integrity of the genome is continuously challenged by both endogenous and exogenous DNA damaging agents. These damaging agents can induce a wide variety of lesions in the DNA, such as double strand breaks, single strand breaks, oxidative lesions and pyrimidine dimers. The cell has evolved intricate DNA damage response mechanisms to counteract the genotoxic effects of these lesions. The two main features of the DNA damage response mechanisms are cell-cycle checkpoint activation and, at the heart of the response, DNA repair. For both damage signalling and repair, chromatin remodelling is most likely a prerequisite. Here, we discuss current knowledge on chromatin remodelling with respect to the cellular response to DNA damage, with emphasis on the response to lesions resolved by nucleotide excision repair. We will discuss the role of histone modifications as well as their displacement or exchange in nucleotide excision repair and make a comparison with their requirement in transcription and double strand break repair.
    Keywords Genetics ; QH426-470 ; Biology (General) ; QH301-705.5 ; Science ; Q ; DOAJ:Genetics ; DOAJ:Biology ; DOAJ:Biology and Life Sciences
    Subject code 612
    Language English
    Publishing date 2008-11-01T00:00:00Z
    Publisher BioMed Central
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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