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Stamatiou K, Huguet F, Serapinas LV, Spanos C, Rappsilber J, Vagnarelli P. Ki-67 is necessary during DNA replication for fork protection and genome stability. Genome Biol 2024; 25:105. [PMID: 38649976 PMCID: PMC11034166 DOI: 10.1186/s13059-024-03243-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 04/09/2024] [Indexed: 04/25/2024] Open
Abstract
BACKGROUND The proliferation antigen Ki-67 has been widely used in clinical settings for cancer staging for many years, but investigations on its biological functions have lagged. Recently, Ki-67 has been shown to regulate both the composition of the chromosome periphery and chromosome behaviour in mitosis as well as to play a role in heterochromatin organisation and gene transcription. However, how the different roles for Ki-67 across the cell cycle are regulated and coordinated remain poorly understood. The progress towards understanding Ki-67 function have been limited by the tools available to deplete the protein, coupled to its abundance and fluctuation during the cell cycle. RESULTS Here, we use a doxycycline-inducible E3 ligase together with an auxin-inducible degron tag to achieve a rapid, acute and homogeneous degradation of Ki-67 in HCT116 cells. This system, coupled with APEX2 proteomics and phospho-proteomics approaches, allows us to show that Ki-67 plays a role during DNA replication. In its absence, DNA replication is severely delayed, the replication machinery is unloaded, causing DNA damage that is not sensed by the canonical pathways and dependent on HUWE1 ligase. This leads to defects in replication and sister chromatids cohesion, but it also triggers an interferon response mediated by the cGAS/STING pathway in all the cell lines tested. CONCLUSIONS We unveil a new function of Ki-67 in DNA replication and genome maintenance that is independent of its previously known role in mitosis and gene regulation.
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Affiliation(s)
- Konstantinos Stamatiou
- College of Health, Medicine and Life Science, Brunel University London, London, UB8 3PH, UK
| | - Florentin Huguet
- College of Health, Medicine and Life Science, Brunel University London, London, UB8 3PH, UK
| | - Lukas V Serapinas
- College of Health, Medicine and Life Science, Brunel University London, London, UB8 3PH, UK
| | - Christos Spanos
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Juri Rappsilber
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, EH16 4SB, UK
- Technische Universitat Berlin, Berlin, 13355, Germany
| | - Paola Vagnarelli
- College of Health, Medicine and Life Science, Brunel University London, London, UB8 3PH, UK.
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Kasprzak A. Prognostic Biomarkers of Cell Proliferation in Colorectal Cancer (CRC): From Immunohistochemistry to Molecular Biology Techniques. Cancers (Basel) 2023; 15:4570. [PMID: 37760539 PMCID: PMC10526446 DOI: 10.3390/cancers15184570] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/04/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023] Open
Abstract
Colorectal cancer (CRC) is one of the most common and severe malignancies worldwide. Recent advances in diagnostic methods allow for more accurate identification and detection of several molecular biomarkers associated with this cancer. Nonetheless, non-invasive and effective prognostic and predictive testing in CRC patients remains challenging. Classical prognostic genetic markers comprise mutations in several genes (e.g., APC, KRAS/BRAF, TGF-β, and TP53). Furthermore, CIN and MSI serve as chromosomal markers, while epigenetic markers include CIMP and many other candidates such as SERP, p14, p16, LINE-1, and RASSF1A. The number of proliferation-related long non-coding RNAs (e.g., SNHG1, SNHG6, MALAT-1, CRNDE) and microRNAs (e.g., miR-20a, miR-21, miR-143, miR-145, miR-181a/b) that could serve as potential CRC markers has also steadily increased in recent years. Among the immunohistochemical (IHC) proliferative markers, the prognostic value regarding the patients' overall survival (OS) or disease-free survival (DFS) has been confirmed for thymidylate synthase (TS), cyclin B1, cyclin D1, proliferating cell nuclear antigen (PCNA), and Ki-67. In most cases, the overexpression of these markers in tissues was related to worse OS and DFS. However, slowly proliferating cells should also be considered in CRC therapy (especially radiotherapy) as they could represent a reservoir from which cells are recruited to replenish the rapidly proliferating population in response to cell-damaging factors. Considering the above, the aim of this article is to review the most common proliferative markers assessed using various methods including IHC and selected molecular biology techniques (e.g., qRT-PCR, in situ hybridization, RNA/DNA sequencing, next-generation sequencing) as prognostic and predictive markers in CRC.
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Affiliation(s)
- Aldona Kasprzak
- Department of Histology and Embryology, University of Medical Sciences, Swiecicki Street 6, 60-781 Poznan, Poland
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Stamatiou K, Chmielewska A, Ohta S, Earnshaw WC, Vagnarelli P. CCDC86 is a novel Ki-67-interacting protein important for cell division. J Cell Sci 2023; 136:286751. [PMID: 36695333 PMCID: PMC10022746 DOI: 10.1242/jcs.260391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 12/08/2022] [Indexed: 01/26/2023] Open
Abstract
The chromosome periphery is a network of proteins and RNAs that coats the outer surface of mitotic chromosomes. Despite the identification of new components, the functions of this complex compartment are poorly characterised. In this study, we identified a novel chromosome periphery-associated protein, CCDC86 (also known as cyclon). Using a combination of RNA interference, microscopy and biochemistry, we studied the functions of CCDC86 in mitosis. CCDC86 depletion resulted in partial disorganisation of the chromosome periphery with alterations in the localisation of Ki-67 (also known as MKI67) and nucleolin (NCL), and the formation of abnormal cytoplasmic aggregates. Furthermore, CCDC86-depleted cells displayed errors in chromosome alignment, altered spindle length and increased apoptosis. These results suggest that, within the chromosome periphery, different subcomplexes that include CCDC86, nucleolin and B23 (nucleophosmin or NPM1) are required for mitotic spindle regulation and correct kinetochore-microtubule attachments, thus contributing to chromosome segregation in mitosis. Moreover, we identified CCDC86 as a MYCN-regulated gene, the expression levels of which represent a powerful marker for prognostic outcomes in neuroblastoma.
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Affiliation(s)
- Konstantinos Stamatiou
- College of Health, Medicine and Life Sciences, Department of Life Sciences, Brunel University London, London UB8 3PH, UK
| | - Aldona Chmielewska
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Shinya Ohta
- Institute for Genetic Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-Ku, Sapporo 060-0815, Japan
| | - William C Earnshaw
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Paola Vagnarelli
- College of Health, Medicine and Life Sciences, Department of Life Sciences, Brunel University London, London UB8 3PH, UK
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Archambault V, Li J, Emond-Fraser V, Larouche M. Dephosphorylation in nuclear reassembly after mitosis. Front Cell Dev Biol 2022; 10:1012768. [PMID: 36268509 PMCID: PMC9576876 DOI: 10.3389/fcell.2022.1012768] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 08/31/2022] [Indexed: 11/13/2022] Open
Abstract
In most animal cell types, the interphase nucleus is largely disassembled during mitotic entry. The nuclear envelope breaks down and chromosomes are compacted into separated masses. Chromatin organization is also mostly lost and kinetochores assemble on centromeres. Mitotic protein kinases play several roles in inducing these transformations by phosphorylating multiple effector proteins. In many of these events, the mechanistic consequences of phosphorylation have been characterized. In comparison, how the nucleus reassembles at the end of mitosis is less well understood in mechanistic terms. In recent years, much progress has been made in deciphering how dephosphorylation of several effector proteins promotes nuclear envelope reassembly, chromosome decondensation, kinetochore disassembly and interphase chromatin organization. The precise roles of protein phosphatases in this process, in particular of the PP1 and PP2A groups, are emerging. Moreover, how these enzymes are temporally and spatially regulated to ensure that nuclear reassembly progresses in a coordinated manner has been partly uncovered. This review provides a global view of nuclear reassembly with a focus on the roles of dephosphorylation events. It also identifies important open questions and proposes hypotheses.
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Affiliation(s)
- Vincent Archambault
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC, Canada
- *Correspondence: Vincent Archambault,
| | - Jingjing Li
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC, Canada
| | - Virginie Emond-Fraser
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC, Canada
| | - Myreille Larouche
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
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Abedin-Do A, Zhang Z, Douville Y, Méthot M, Bernatchez J, Rouabhia M. Electrical stimulation promotes the wound-healing properties of diabetic human skin fibroblasts. J Tissue Eng Regen Med 2022; 16:643-652. [PMID: 35442544 DOI: 10.1002/term.3305] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 04/09/2022] [Accepted: 04/11/2022] [Indexed: 01/09/2023]
Abstract
This study evaluated the effect of low (20 and 40 mV/mm) intensities of electrical stimulation on the proliferation and migration of skin fibroblasts from diabetic donors. We also examined the effect of electrical stimulation on modulating the capacity of fibroblasts to contract collagen gel, express alpha-smooth muscle actin, and secrete proteolytic enzymes involved in regulating extracellular matrix synthesis and degradation. Our study shows that 20 and 40 mV/mm of stimulation increased the growth of fibroblasts extracted from diabetic patients but not from non-diabetic donors. Electrical stimulation increased the migration of diabetic fibroblasts, their capacity to contract collagen gel, and the expression of alpha-smooth muscle actin and promoted different proteolytic enzymes involved in accelerating wound healing. Overall results confirm the effectiveness of electrical stimulation in modulating the wound healing activities of fibroblasts extracted from diabetic skin donors. This study, therefore, suggests the possible use of electrical stimulation to promote diabetic foot ulcer healing by stimulating the wound healing properties of skin fibroblasts.
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Affiliation(s)
- Atieh Abedin-Do
- Groupe de Recherche en Écologie Buccale, Faculté de Médecine Dentaire, Université Laval, Quebec, QC, Canada.,Axe Médecine Régénératrice, Centre de Recherche du CHU de Québec, Département de Chirurgie, Faculté de Médecine, Université Laval, Quebec, QC, Canada
| | - Ze Zhang
- Axe Médecine Régénératrice, Centre de Recherche du CHU de Québec, Département de Chirurgie, Faculté de Médecine, Université Laval, Quebec, QC, Canada
| | - Yvan Douville
- Axe Médecine Régénératrice, Centre de Recherche du CHU de Québec, Département de Chirurgie, Faculté de Médecine, Université Laval, Quebec, QC, Canada
| | - Mireille Méthot
- Axe Médecine Régénératrice, Centre de Recherche du CHU de Québec, Département de Chirurgie, Faculté de Médecine, Université Laval, Quebec, QC, Canada
| | - Julien Bernatchez
- Axe Médecine Régénératrice, Centre de Recherche du CHU de Québec, Département de Chirurgie, Faculté de Médecine, Université Laval, Quebec, QC, Canada
| | - Mahmoud Rouabhia
- Groupe de Recherche en Écologie Buccale, Faculté de Médecine Dentaire, Université Laval, Quebec, QC, Canada
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