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Krishnan V. The RUNX Family of Proteins, DNA Repair, and Cancer. Cells 2023; 12:cells12081106. [PMID: 37190015 DOI: 10.3390/cells12081106] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/04/2023] [Accepted: 04/05/2023] [Indexed: 05/17/2023] Open
Abstract
The RUNX family of transcription factors, including RUNX1, RUNX2, and RUNX3, are key regulators of development and can function as either tumor suppressors or oncogenes in cancer. Emerging evidence suggests that the dysregulation of RUNX genes can promote genomic instability in both leukemia and solid cancers by impairing DNA repair mechanisms. RUNX proteins control the cellular response to DNA damage by regulating the p53, Fanconi anemia, and oxidative stress repair pathways through transcriptional or non-transcriptional mechanisms. This review highlights the importance of RUNX-dependent DNA repair regulation in human cancers.
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Affiliation(s)
- Vaidehi Krishnan
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
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Dutta B, Osato M. The RUNX Family, a Novel Multifaceted Guardian of the Genome. Cells 2023; 12:255. [PMID: 36672189 PMCID: PMC9856552 DOI: 10.3390/cells12020255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 12/24/2022] [Accepted: 12/30/2022] [Indexed: 01/11/2023] Open
Abstract
The DNA repair machinery exists to protect cells from daily genetic insults by orchestrating multiple intrinsic and extrinsic factors. One such factor recently identified is the Runt-related transcription factor (RUNX) family, a group of proteins that act as a master transcriptional regulator for multiple biological functions such as embryonic development, stem cell behaviors, and oncogenesis. A significant number of studies in the past decades have delineated the involvement of RUNX proteins in DNA repair. Alterations in RUNX genes cause organ failure and predisposition to cancers, as seen in patients carrying mutations in the other well-established DNA repair genes. Herein, we review the currently existing findings and provide new insights into transcriptional and non-transcriptional multifaceted regulation of DNA repair by RUNX family proteins.
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Affiliation(s)
- Bibek Dutta
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
| | - Motomi Osato
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
- International Research Center for Medical Sciences, Kumamoto University, Kumamoto 860-0811, Japan
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Vasilyev SA, Savchenko RR, Belenko AA, Skryabin NA, Sleptsov AA, Fishman VS, Murashkina AA, Gribova OV, Startseva ZA, Sukhikh ES, Vertinskiy AV, Sukhikh LG, Serov OL, Lebedev IN. ADAMTS1 Is Differentially Expressed in Human Lymphocytes with Various Frequencies of Endogenous γH2AX Foci and Radiation-Induced Micronuclei. RUSS J GENET+ 2022. [DOI: 10.1134/s102279542210012x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Shao L, Ning K, Wang J, Cheng F, Wang S, Qiu J. The Large Nonstructural Protein (NS1) of Human Bocavirus 1 Directly Interacts with Ku70, Which Plays an Important Role in Virus Replication in Human Airway Epithelia. J Virol 2022; 96:e0184021. [PMID: 34878919 PMCID: PMC8865542 DOI: 10.1128/jvi.01840-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 11/22/2021] [Indexed: 12/16/2022] Open
Abstract
Human bocavirus 1 (HBoV1), an autonomous human parvovirus, causes acute respiratory tract infections in young children. HBoV1 infects well-differentiated (polarized) human airway epithelium cultured at an air-liquid interface (HAE-ALI). HBoV1 expresses a large nonstructural protein, NS1, that is essential for viral DNA replication. HBoV1 infection of polarized human airway epithelial cells induces a DNA damage response (DDR) that is critical to viral DNA replication involving DNA repair with error-free Y-family DNA polymerases. HBoV1 NS1 or the isoform NS1-70 per se induces a DDR. In this study, using the second-generation proximity-dependent biotin identification (BioID2) approach, we identified that Ku70 is associated with the NS1-BioID2 pulldown complex through a direct interaction with NS1. Biolayer interferometry (BLI) assay determined a high binding affinity of NS1 with Ku70, which has an equilibrium dissociation constant (KD) value of 0.16 μM and processes the strongest interaction at the C-terminal domain. The association of Ku70 with NS1 was also revealed during HBoV1 infection of HAE-ALI. Knockdown of Ku70 and overexpression of the C-terminal domain of Ku70 significantly decreased HBoV1 replication in HAE-ALI. Thus, our study provides, for the first time, a direct interaction of parvovirus large nonstructural protein NS1 with Ku70. IMPORTANCE Parvovirus infection induces a DNA damage response (DDR) that plays a pivotal role in viral DNA replication. The DDR includes activation of ATM (ataxia telangiectasia mutated), ATR (ATM- and RAD3-related), and DNA-PKcs (DNA-dependent protein kinase catalytic subunit). The large nonstructural protein (NS1) often plays a role in the induction of DDR; however, how the DDR is induced during parvovirus infection or simply by the NS1 is not well studied. Activation of DNA-PKcs has been shown as one of the key DDR pathways in DNA replication of HBoV1. We identified that HBoV1 NS1 directly interacts with Ku70, but not Ku80, of the Ku70/Ku80 heterodimer at high affinity. This interaction is also important for HBoV1 replication in HAE-ALI. We propose that the interaction of NS1 with Ku70 recruits the Ku70/Ku80 complex to the viral DNA replication center, which activates DNA-PKcs and facilitates viral DNA replication.
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Affiliation(s)
- Liting Shao
- Beijing Institute of Radiation Medicine, Beijing, China
| | - Kang Ning
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Jianke Wang
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Fang Cheng
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Shengqi Wang
- Beijing Institute of Radiation Medicine, Beijing, China
| | - Jianming Qiu
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
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RUNX3 Transcript Variants Have Distinct Roles in Ovarian Carcinoma and Differently Influence Platinum Sensitivity and Angiogenesis. Cancers (Basel) 2021; 13:cancers13030476. [PMID: 33530588 PMCID: PMC7866085 DOI: 10.3390/cancers13030476] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 01/15/2021] [Accepted: 01/21/2021] [Indexed: 12/14/2022] Open
Abstract
Simple Summary Epithelial ovarian cancer treatment is limited by missing predictive markers, frequent chemotherapy resistance and an incomplete understanding of the biology of tumors. Earlier work proved that hypermethylation of the gene RUNX3 coding for a transcription factor has prognostic value, and RUNX3 transcript variant overexpression, regulated by this epigenetic mechanism, influences cisplatin sensitivity and malignant properties of cells contrary. The present data validate RUNX3 transcript variant-specific effects for high-grade serous ovarian cancer and identify RUNX3-regulated genes and processes. Specifically, DNA damage repair and angiogenesis are influenced by RUNX3, and transcript variant 1 mediates stronger carcinogenic properties. Abstract The prognosis of late-stage epithelial ovarian cancer (EOC) patients is affected by chemotherapy response and the malignant potential of the tumor cells. In earlier work, we identified hypermethylation of the runt-related transcription factor 3 gene (RUNX3) as a prognostic biomarker and contrary functions of transcript variants (TV1 and TV2) in A2780 and SKOV3 cells. The aim of the study was to further validate these results and to increase the knowledge about RUNX3 function in EOC. New RUNX3 overexpression models of high-grade serous ovarian cancer (HGSOC) were established and analyzed for phenotypic (IC50 determination, migration, proliferation and angiogenesis assay, DNA damage analysis) and transcriptomic consequences (NGS) of RUNX3 TV1 and TV2 overexpression. Platinum sensitivity was affected by a specific transcript variant depending on BRCA background. RUNX3 TV2 induced an increased sensitivity in BRCA1wt cells (OVCAR3), whereas TV1 increased the sensitivity and induced a G2/M arrest under treatment in BRCA1mut cells (A13-2-12). These different phenotypes relate to differences in DNA repair: homologous recombination deficient A13-2-12 cells show less γH2AX foci despite higher levels of Pt-DNA adducts. RNA-Seq analyses prove transcript variant and cell-line-specific RUNX3 effects. Pathway analyses revealed another clinically important function of RUNX3—regulation of angiogenesis. This was confirmed by thrombospondin1 analyses, HUVEC spheroid sprouting assays and proteomic profiling. Importantly, conditioned media (CM) from RUNX3 TV1 overexpressing A13-2-12 cells induced an increased HUVEC sprouting. Altogether, the presented data support the hypothesis of different functions of RUNX3 transcript variants related to the clinically relevant processes—platinum resistance and angiogenesis.
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A Regulatory Role for RUNX1, RUNX3 in the Maintenance of Genomic Integrity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 962:491-510. [PMID: 28299675 DOI: 10.1007/978-981-10-3233-2_29] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
All human cells are constantly attacked by endogenous and exogenous agents that damage the integrity of their genomes. Yet, the ensuing damage is mostly fixed and very rarely gives rise to genomic defects that promote cancer formation. This is due to the co-ordinated functioning of DNA repair proteins and checkpoint mechanisms that accurately detect and repair DNA damage to ensure genomic fitness. According to accumulating evidence, the RUNX family of transcription factors participate in the maintenance of genomic stability through transcriptional and non-transcriptional mechanisms. RUNX1 and RUNX3 maintain genomic integrity in a transcriptional manner by regulating the transactivation of apoptotic genes following DNA damage via complex formation with p53. RUNX1 and RUNX3 also maintain genomic integrity in a non-transcriptional manner during interstand crosslink repair by promoting the recruitment of FANCD2 to sites of DNA damage. Since RUNX genes are frequently aberrant in human cancer, here, we argue that one of the major modes by which RUNX inactivation promotes neoplastic transformation is through the loss of genomic integrity. In particular, there exists strong evidence that leukemic RUNX1-fusions such as RUNX1-ETO disrupt genomic integrity and induce a "mutator" phenotype during the early stages of leukemogenesis. Consistent with increased DNA damage accumulation induced by RUNX1-ETO, PARP inhibition has been shown to be an effective synthetic-lethal therapeutic approach against RUNX1-ETO expressing leukemias. Here, in this chapter we will examine current evidence suggesting that the tumor suppressor potential of RUNX proteins can be at least partly attributed to their ability to ensure high-fidelity DNA repair and thus prevent mutational accumulation during cancer progression.
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Haider A, Steininger A, Ullmann R, Hummel M, Dimitrova L, Beyer M, Vandersee S, Lenze D, Sterry W, Assaf C, Möbs M. Inactivation of RUNX3/p46 Promotes Cutaneous T-Cell Lymphoma. J Invest Dermatol 2016; 136:2287-2296. [PMID: 27377697 DOI: 10.1016/j.jid.2016.05.126] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 05/30/2016] [Accepted: 05/31/2016] [Indexed: 12/31/2022]
Abstract
The key role of RUNX3 in physiological T-cell differentiation has been extensively documented. However, information on its relevance for the development of human T-cell lymphomas or leukemias is scarce. Here, we show that alterations of RUNX3 by either heterozygous deletion or methylation of its distal promoter can be observed in the tumor cells of 15 of 21 (71%) patients suffering from Sézary syndrome, an aggressive variant of cutaneous T-cell lymphoma. As a consequence, mRNA levels of RUNX3/p46, the isoform controlled by the distal promoter, are significantly lower in Sézary syndrome tumor cells. Re-expression of RUNX3/p46 reduces cell viability and promotes apoptosis in a RUNX3/p46low cell line of cutaneous T-cell lymphoma. Based on this, we present evidence that RUNX3 can act as a tumor suppressor in a human T-cell malignancy and suggest that this effect is predominantly mediated through transcripts from its distal promoter, in particular RUNX3/p46.
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Affiliation(s)
- Ahmed Haider
- Department of Dermatology, Charité - Universitaetsmedizin Berlin, Berlin, Germany
| | - Anne Steininger
- Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Reinhard Ullmann
- Max Planck Institute for Molecular Genetics, Berlin, Germany; Institut für Radiobiologie der Bundeswehr in Verbindung mit der Universität Ulm, Munich, Germany
| | - Michael Hummel
- Institute of Pathology, Charité - Universitaetsmedizin Berlin, Berlin, Germany
| | - Lora Dimitrova
- Institute of Pathology, Charité - Universitaetsmedizin Berlin, Berlin, Germany
| | - Marc Beyer
- Department of Dermatology, Charité - Universitaetsmedizin Berlin, Berlin, Germany
| | - Staffan Vandersee
- Department of Dermatology, Charité - Universitaetsmedizin Berlin, Berlin, Germany; Central German Armed Forces hospital, Department of Dermatology and Allergy, Koblenz, Germany
| | - Dido Lenze
- Institute of Pathology, Charité - Universitaetsmedizin Berlin, Berlin, Germany
| | - Wolfram Sterry
- Department of Dermatology, Charité - Universitaetsmedizin Berlin, Berlin, Germany
| | - Chalid Assaf
- Department of Dermatology, Charité - Universitaetsmedizin Berlin, Berlin, Germany; Department of Dermatology, HELIOS Klinikum Krefeld, Krefeld, Germany.
| | - Markus Möbs
- Department of Dermatology, Charité - Universitaetsmedizin Berlin, Berlin, Germany; Institute of Pathology, Charité - Universitaetsmedizin Berlin, Berlin, Germany.
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Abstract
RUNX proteins belong to a family of metazoan transcription factors that serve as master regulators of development. They are frequently deregulated in human cancers, indicating a prominent and, at times, paradoxical role in cancer pathogenesis. The contextual cues that direct RUNX function represent a fast-growing field in cancer research and could provide insights that are applicable to early cancer detection and treatment. This Review describes how RUNX proteins communicate with key signalling pathways during the multistep progression to malignancy; in particular, we highlight the emerging partnership of RUNX with p53 in cancer suppression.
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Affiliation(s)
- Yoshiaki Ito
- 1] Cancer Science Institute of Singapore, National University of Singapore, Center for Translational Medicine, 14 Medical Drive #12-01, 117599, Singapore. [2]
| | - Suk-Chul Bae
- 1] Department of Biochemistry, School of Medicine, and Institute for Tumour Research, Chungbuk National University, Cheongju, 361763, South Korea. [2]
| | - Linda Shyue Huey Chuang
- 1] Cancer Science Institute of Singapore, National University of Singapore, Center for Translational Medicine, 14 Medical Drive #12-01, 117599, Singapore. [2]
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Maccani JZJ, Koestler DC, Houseman EA, Marsit CJ, Kelsey KT. Placental DNA methylation alterations associated with maternal tobacco smoking at the RUNX3 gene are also associated with gestational age. Epigenomics 2013; 5:619-30. [PMID: 24283877 PMCID: PMC3982305 DOI: 10.2217/epi.13.63] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
AIMS The developmental origins of health and disease hypothesis states that later-life disease may be influenced by the quality of the in utero environment. Environmental toxicants can have detrimental effects on fetal development, potentially through effects on placental development and function. Maternal smoking during pregnancy is associated with low birth weight, preterm birth and other complications, and exposure to cigarette smoke in utero has been linked to gross pathologic and molecular changes to the placenta, including differential DNA methylation in placental tissue. The aim of this study was to investigate the relationship between maternal smoking during pregnancy, methylation changes in the placenta and gestational age. MATERIALS & METHODS We used Illumina(®)'s (CA, USA) Human Methylation27 BeadChip technology platform to investigate the methylation status of 21,551 autosomal, non-SNP-associated CpG loci in DNA extracted from 206 human placentas and examined loci whose variation in methylation was associated with maternal smoking during pregnancy. RESULTS We found that methylation patterns of a number of loci within the RUNX3 gene were significantly associated with smoking during pregnancy, and one of these loci was associated with decreased gestational age (p = 0.04). CONCLUSION Our findings, demonstrating maternal smoking-induced changes in DNA methylation at specific loci, suggest a mechanism by which in utero tobacco smoke exposure could exert its detrimental effects upon the health of the fetus.
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Affiliation(s)
- Jennifer ZJ Maccani
- Department of Pathology & Laboratory Medicine, Brown University, Providence, RI, USA
| | - Devin C Koestler
- Section of Biostatistics & Epidemiology, Department of Community & Family Medicine, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | | | - Carmen J Marsit
- Section of Biostatistics & Epidemiology, Department of Community & Family Medicine, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
- Department of Pharmacology & Toxicology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Karl T Kelsey
- Department of Pathology & Laboratory Medicine, Brown University, Providence, RI, USA
- Department of Epidemiology, Brown University, Providence, RI, USA
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Chuang LSH, Ito K, Ito Y. RUNX family: Regulation and diversification of roles through interacting proteins. Int J Cancer 2012. [PMID: 23180629 DOI: 10.1002/ijc.27964] [Citation(s) in RCA: 151] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Runt-related transcription factors (RUNX) belong to an ancient family of metazoan genes involved in developmental processes. Through multiple protein-interacting partners, RUNX proteins have been implicated in diverse signaling pathways and cellular processes. The frequent inactivation of RUNX genes in cancer indicates crucial roles for RUNX in tumor suppression. This review discusses the abilities of RUNX proteins, in particular RUNX3, to integrate oncogenic signals or environmental cues and to initiate appropriate tumor suppressive responses.
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Chuang LSH, Lai SK, Murata-Hori M, Yamada A, Li HY, Gunaratne J, Ito Y. RUNX3 interactome reveals novel centrosomal targeting of RUNX family of transcription factors. Cell Cycle 2012; 11:1938-47. [PMID: 22544322 DOI: 10.4161/cc.20278] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
RUNX family proteins are critical regulators of lineage differentiation during development. The high prevalence of RUNX mutation/epigenetic inactivation in human cancer indicates a causative role for dysfunctional RUNX in carcinogenesis. This is supported by well-documented evidence of functional interaction of RUNX with components of major oncogenic or tumor suppressive signaling pathways such as TGFβ and Wnt. Here, we explore the binding partners of RUNX3 proteins to further define the scope of RUNX3 function. Using a mass spectrometry-based approach, we found that RUNX3 binds to centrosomal protein rootletin. This led us to uncover the presence of RUNX proteins at the centrosome. Our findings suggest a potential function for RUNX3 during mitosis.
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KARP-1 works as a heterodimer with Ku70, but the function of KARP-1 cannot perfectly replace that of Ku80 in DSB repair. Exp Cell Res 2011; 317:2267-75. [PMID: 21756904 DOI: 10.1016/j.yexcr.2011.06.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 06/22/2011] [Accepted: 06/25/2011] [Indexed: 11/20/2022]
Abstract
Ku, the heterodimer of Ku70 and Ku80, plays an essential role in the DNA double-strand break (DSB) repair pathway, i.e., non-homologous end-joining (NHEJ). Two isoforms of Ku80 encoded by the same genes, namely, Ku80 and KARP-1 are expressed and function in primate cells, but not in rodent cells. Ku80 works as a heterodimer with Ku70. However, it is not yet clear whether KARP-1 forms a heterodimer with Ku70 and works as a heterodimer. Although KARP-1 appears to work in NHEJ, its physiological role remains unclear. In this study, we established and characterized EGFP-KARP-1-expressing xrs-6 cell lines, EGFP-KARP-1/xrs-6. We found that nuclear localization signal (NLS) of KARP-1 is localized in the C-terminal region. Our data showed that KARP-1 localizes within the nucleus in NLS-dependent and NLS-independent manner and forms a heterodimer with Ku70, and stabilizes Ku70. On the other hand, EGFP-KARP-1 could not perfectly complement the radiosensitivity and DSB repair activity of Ku80-deficient xrs-6 cells. Furthermore, KARP-1 could not accumulate at DSBs faster than Ku80, although EGFP-KARP-1 accumulates at DSBs. Our data demonstrate that the function of KARP-1 could not perfectly replace that of Ku80 in DSB repair, although KARP-1 has some biochemical properties, which resemble those of Ku80, and works as a heterodimer with Ku70. On the other hand, the number of EGFP-KARP-1-expressing xrs-6 cells showing pan-nuclear γ-H2AX staining significantly increases following X-irradiation, suggesting that KARP-1 may have a novel role in DSB response.
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Shahi A, Lee JH, Kang Y, Lee SH, Hyun JW, Chang IY, Jun JY, You HJ. Mismatch-repair protein MSH6 is associated with Ku70 and regulates DNA double-strand break repair. Nucleic Acids Res 2010; 39:2130-43. [PMID: 21075794 PMCID: PMC3064773 DOI: 10.1093/nar/gkq1095] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
MSH6, a key component of the MSH2–MSH6 complex, plays a fundamental role in the repair of mismatched DNA bases. Herein, we report that MSH6 is a novel Ku70-interacting protein identified by yeast two-hybrid screening. Ku70 and Ku86 are two key regulatory subunits of the DNA-dependent protein kinase, which plays an essential role in repair of DNA double-strand breaks (DSBs) through the non-homologous end-joining (NEHJ) pathway. We found that association of Ku70 with MSH6 is enhanced in response to treatment with the radiomimetic drug neocarzinostatin (NCS) or ionizing radiation (IR), a potent inducer of DSBs. Furthermore, MSH6 exhibited diffuse nuclear staining in the majority of untreated cells and forms discrete nuclear foci after NCS or IR treatment. MSH6 colocalizes with γ-H2AX at sites of DNA damage after NCS or IR treatment. Cells depleted of MSH6 accumulate high levels of persistent DSBs, as detected by formation of γ-H2AX foci and by the comet assay. Moreover, MSH6-deficient cells were also shown to exhibit impaired NHEJ, which could be rescued by MSH6 overexpression. MSH6-deficient cells were hypersensitive to NCS- or IR-induced cell death, as revealed by a clonogenic cell-survival assay. These results suggest a potential role for MSH6 in DSB repair through upregulation of NHEJ by association with Ku70.
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Affiliation(s)
- Ankita Shahi
- DNA Repair Research Center, Department of Pharmacology, Chosun University School of Medicine, 375 Seosuk-dong, Gwangju, 501-759, South Korea
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Chuang LSH, Ito Y. RUNX3 is multifunctional in carcinogenesis of multiple solid tumors. Oncogene 2010; 29:2605-15. [DOI: 10.1038/onc.2010.88] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Molecular pathology of RUNX3 in human carcinogenesis. Biochim Biophys Acta Rev Cancer 2009; 1796:315-31. [PMID: 19682550 DOI: 10.1016/j.bbcan.2009.07.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Accepted: 07/31/2009] [Indexed: 12/12/2022]
Abstract
A major goal of molecular biology is to elucidate the mechanisms underlying cancer development and progression in order to achieve early detection, better diagnosis and staging and novel preventive and therapeutic strategies. We feel that an understanding of Runt-related transcription factor 3 (RUNX3)-regulated biological pathways will directly impact our knowledge of these areas of human carcinogenesis. The RUNX3 transcription factor is a downstream effector of the transforming growth factor-beta (TGF-beta) signaling pathway, and has a critical role in the regulation of cell proliferation and cell death by apoptosis, and in angiogenesis, cell adhesion and invasion. We previously identified RUNX3 as a major gastric tumor suppressor by establishing a causal relationship between loss of function and gastric carcinogenesis. More recently, we showed that RUNX3 functions as a bona fide initiator of colonic carcinogenesis by linking the Wnt oncogenic and TGF-beta tumor suppressive pathways. Apart from gastric and colorectal cancers, a multitude of epithelial cancers exhibit inactivation of RUNX3, thereby making it a putative tumor suppressor in human neoplasia. This review highlights our current understanding of the molecular mechanisms of RUNX3 inactivation in the context of cancer development and progression.
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Kim HR, Oh BC, Choi JK, Bae SC. Pim-1 kinase phosphorylates and stabilizes RUNX3 and alters its subcellular localization. J Cell Biochem 2008; 105:1048-58. [DOI: 10.1002/jcb.21906] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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