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Riego ML, Meher PK, Brzozowska B, Akuwudike P, Bucher M, Oestreicher U, Lundholm L, Wojcik A. Chromosomal damage, gene expression and alternative transcription in human lymphocytes exposed to mixed ionizing radiation as encountered in space. Sci Rep 2024; 14:11502. [PMID: 38769353 PMCID: PMC11106305 DOI: 10.1038/s41598-024-62313-7] [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: 08/05/2023] [Accepted: 05/15/2024] [Indexed: 05/22/2024] Open
Abstract
Astronauts travelling in space will be exposed to mixed beams of particle radiation and photons. Exposure limits that correspond to defined cancer risk are calculated by multiplying absorbed doses by a radiation-type specific quality factor that reflects the biological effectiveness of the particle without considering possible interaction with photons. We have shown previously that alpha radiation and X-rays may interact resulting in synergistic DNA damage responses in human peripheral blood lymphocytes but the level of intra-individual variability was high. In order to assess the variability and validate the synergism, blood from two male donors was drawn at 9 time points during 3 seasons of the year and exposed to 0-2 Gy of X-rays, alpha particles or 1:1 mixture of both (half the dose each). DNA damage response was quantified by chromosomal aberrations and by mRNA levels of 3 radiation-responsive genes FDXR, CDKN1A and MDM2 measured 24 h post exposure. The quality of response in terms of differential expression of alternative transcripts was assessed by using two primer pairs per gene. A consistently higher than expected effect of mixed beams was found in both donors for chromosomal aberrations and gene expression with some seasonal variability for the latter. No synergy was detected for alternative transcription.
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Affiliation(s)
- Milagrosa López Riego
- Centre for Radiation Protection Research, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius Väg 20C, 106 91, Stockholm, Sweden
| | - Prabodha Kumar Meher
- Centre for Radiation Protection Research, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius Väg 20C, 106 91, Stockholm, Sweden
| | - Beata Brzozowska
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland
| | - Pamela Akuwudike
- Centre for Radiation Protection Research, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius Väg 20C, 106 91, Stockholm, Sweden
| | - Martin Bucher
- Federal Office for Radiation Protection, Oberschleissheim, Germany
| | | | - Lovisa Lundholm
- Centre for Radiation Protection Research, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius Väg 20C, 106 91, Stockholm, Sweden
| | - Andrzej Wojcik
- Centre for Radiation Protection Research, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius Väg 20C, 106 91, Stockholm, Sweden.
- Institute of Biology, Jan Kochanowski University, Kielce, Poland.
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Akuwudike P, López-Riego M, Ginter J, Cheng L, Wieczorek A, Życieńska K, Łysek-Gładysińska M, Wojcik A, Brzozowska B, Lundholm L. Mechanistic insights from high resolution DNA damage analysis to understand mixed radiation exposure. DNA Repair (Amst) 2023; 130:103554. [PMID: 37595330 DOI: 10.1016/j.dnarep.2023.103554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 07/31/2023] [Accepted: 08/07/2023] [Indexed: 08/20/2023]
Abstract
Cells exposed to densely ionising high and scattered low linear energy transfer (LET) radiation (50 % dose of each) react more strongly than to the same dose of each separately. The relationship between DNA double strand break location inside the nucleus and chromatin structure was evaluated, using high-resolution transmission electron microscopy (TEM) in breast cancer MDA-MB-231 cells at 30 min post 5 Gy. Additionally, response to high and/or low LET radiation was assessed using single (1 ×1.5 Gy) versus fractionated dose delivery (5 ×0.3 Gy). By TEM analysis, the highest total number of γH2AX nanobeads were found in cells irradiated with alpha radiation just prior to gamma radiation (called mixed beam), followed by alpha, then gamma radiation. γH2AX foci induced by mixed beam radiation tended to be surrounded by open chromatin (lighter TEM regions), yet foci containing the highest number of beads, i.e. larger foci representing complex damage, remained in the heterochromatic areas. The γH2AX large focus area was also greater in mixed beam-treated cells when analysed by immunofluorescence. Fractionated mixed beams given daily induced the strongest reduction in cell viability and colony formation in MDA-MB-231 and osteosarcoma U2OS cells compared to the other radiation qualities, as well as versus acute exposure. This may partially be explained by recurring low LET oxidative DNA damage by every fraction together with a delay in recompaction of chromatin after high LET, demonstrated by low levels of heterochromatin marker H3K9me3 at 2 h after the last mixed beam fraction in MDA-MB-231. In conclusion, early differences in response to complex DNA damage may lead to a stronger cell kill induced by fractionated exposure, which suggest a therapeutic potential of combined high and low LET irradiation.
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Affiliation(s)
- Pamela Akuwudike
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
| | - Milagrosa López-Riego
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
| | - Józef Ginter
- Biomedical Physics Division, Faculty of Physics, University of Warsaw, 02-093 Warsaw, Poland
| | - Lei Cheng
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
| | - Anna Wieczorek
- Division of Medical Biology, Institute of Biology, Jan Kochanowski University, 25-406 Kielce, Poland
| | - Katarzyna Życieńska
- Biomedical Physics Division, Faculty of Physics, University of Warsaw, 02-093 Warsaw, Poland
| | | | - Andrzej Wojcik
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
| | - Beata Brzozowska
- Biomedical Physics Division, Faculty of Physics, University of Warsaw, 02-093 Warsaw, Poland
| | - Lovisa Lundholm
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden.
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López-Riego M, Płódowska M, Lis-Zajęcka M, Jeziorska K, Tetela S, Węgierek-Ciuk A, Sobota D, Braziewicz J, Lundholm L, Lisowska H, Wojcik A. The DNA damage response to radiological imaging: from ROS and γH2AX foci induction to gene expression responses in vivo. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2023:10.1007/s00411-023-01033-4. [PMID: 37335333 DOI: 10.1007/s00411-023-01033-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 06/03/2023] [Indexed: 06/21/2023]
Abstract
Candidate ionising radiation exposure biomarkers must be validated in humans exposed in vivo. Blood from patients undergoing positron emission tomography-computed tomography scan (PET-CT) and skeletal scintigraphy (scintigraphy) was drawn before (0 h) and after (2 h) the procedure for correlation analyses of the response of selected biomarkers with radiation dose and other available patient information. FDXR, CDKN1A, BBC3, GADD45A, XPC, and MDM2 expression was determined by qRT-PCR, DNA damage (γH2AX) by flow cytometry, and reactive oxygen species (ROS) levels by flow cytometry using the 2', 7'-dichlorofluorescein diacetate test in peripheral blood mononuclear cells (PBMC). For ROS experiments, 0- and 2-h samples were additionally exposed to UVA to determine whether diagnostic irradiation conditioned the response to further oxidative insult. With some exceptions, radiological imaging induced weak γH2AX foci, ROS and gene expression fold changes, the latter with good coherence across genes within a patient. Diagnostic imaging did not influence oxidative stress in PBMC successively exposed to UVA. Correlation analyses with patient characteristics led to low correlation coefficient values. γH2AX fold change, which correlated positively with gene expression, presented a weak positive correlation with injected activity, indicating a radiation-induced subtle increase in DNA damage and subsequent activation of the DNA damage response pathway. The exposure discrimination potential of these biomarkers in the absence of control samples as frequently demanded in radiological emergencies, was assessed using raw data. These results suggest that the variability of the response in heterogeneous populations might complicate identifying individuals exposed to low radiation doses.
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Affiliation(s)
- Milagrosa López-Riego
- Centre for Radiation Protection Research, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
| | - Magdalena Płódowska
- Department of Medical Biology, Institute of Biology, Jan Kochanowski University, Kielce, Poland
| | - Milena Lis-Zajęcka
- Department of Medical Biology, Institute of Biology, Jan Kochanowski University, Kielce, Poland
| | - Kamila Jeziorska
- Department of Medical Biology, Institute of Biology, Jan Kochanowski University, Kielce, Poland
| | - Sylwia Tetela
- Department of Medical Biology, Institute of Biology, Jan Kochanowski University, Kielce, Poland
| | - Aneta Węgierek-Ciuk
- Department of Medical Biology, Institute of Biology, Jan Kochanowski University, Kielce, Poland
| | - Daniel Sobota
- Department of Medical Physics, Institute of Biology, Jan Kochanowski University, Kielce, Poland
| | - Janusz Braziewicz
- Department of Medical Physics, Institute of Biology, Jan Kochanowski University, Kielce, Poland
- Department of Nuclear Medicine With Positron Emission Tomography (PET) Unit, Holy Cross Cancer Centre, Kielce, Poland
| | - Lovisa Lundholm
- Centre for Radiation Protection Research, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Halina Lisowska
- Department of Medical Biology, Institute of Biology, Jan Kochanowski University, Kielce, Poland
| | - Andrzej Wojcik
- Centre for Radiation Protection Research, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- Department of Medical Biology, Institute of Biology, Jan Kochanowski University, Kielce, Poland
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Tartas A, Lundholm L, Scherthan H, Wojcik A, Brzozowska B. The order of sequential exposure of U2OS cells to gamma and alpha radiation influences the formation and decay dynamics of NBS1 foci. PLoS One 2023; 18:e0286902. [PMID: 37307266 DOI: 10.1371/journal.pone.0286902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 05/25/2023] [Indexed: 06/14/2023] Open
Abstract
DNA double strand breaks (DSBs) are a deleterious form of DNA damage. Densely ionising alpha radiation predominantly induces complex DSBs and sparsely ionising gamma radiation-simple DSBs. We have shown that alphas and gammas, when applied simultaneously, interact in producing a higher DNA damage response (DDR) than predicted by additivity. The mechanisms of the interaction remain obscure. The present study aimed at testing whether the sequence of exposure to alphas and gammas has an impact on the DDR, visualised by live NBS1-GFP (green fluorescent protein) focus dynamics in U2OS cells. Focus formation, decay, intensity and mobility were analysed up to 5 h post exposure. Focus frequencies directly after sequential alpha → gamma and gamma → alpha exposure were similar to gamma alone, but gamma → alpha foci quickly declined below the expected values. Focus intensities and areas following alpha alone and alpha → gamma were larger than after gamma alone and gamma → alpha. Focus movement was most strongly attenuated by alpha → gamma. Overall, sequential alpha → gamma exposure induced the strongest change in characteristics and dynamics of NBS1-GFP foci. Possible explanation is that activation of the DDR is stronger when alpha-induced DNA damage precedes gamma-induced DNA damage.
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Affiliation(s)
- Adrianna Tartas
- Biomedical Physics Division, Faculty of Physics, University of Warsaw, Warsaw, Poland
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Lovisa Lundholm
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Harry Scherthan
- Bundeswehr Institute of Radiobiology Affiliated to the Univ. of Ulm, Munich, Germany
| | - Andrzej Wojcik
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- Institute of Biology, Jan Kochanowski University, Kielce, Poland
| | - Beata Brzozowska
- Biomedical Physics Division, Faculty of Physics, University of Warsaw, Warsaw, Poland
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Ding D, Zhang Y, Zhang X, Shi K, Shang W, Ying J, Wang L, Chen Z, Hong H. MiR-30a-3p Suppresses the Growth and Development of Lung Adenocarcinoma Cells Through Modulating GOLM1/JAK-STAT Signaling. Mol Biotechnol 2022; 64:1143-1151. [PMID: 35438415 DOI: 10.1007/s12033-022-00497-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 04/11/2022] [Indexed: 11/27/2022]
Abstract
A considerable amount of people succumbs to lung adenocarcinoma (LUAD) due to its high incidence and mortality. This study attempted to reveal the impacts of GOLM1 on LUAD. This work analyzed GOLM1 expression in LUAD and normal tissue and studied its prognostic value utilizing data from The Cancer Genome Atlas. RNA and protein levels were, respectively, determined utilizing qRT-PCR and western blot. Cell-aggressive behaviors were assessed employing Cell Counting Kit-8, scratch healing, and Transwell assays. The targetting relationship between GOLM1 and miR-30a-3p was assayed by dual-luciferase method. GOLM1 up-regulation in LUAD was found in TCGA and it was also a negative factor for survival in patients. GOLM1 overexpression promoted cell progression in LUAD. Down-regulated miR-30a-3p in LUAD was an upstream regulatory miRNA of GOLM1 in terms of molecular mechanism. Further, rescue assays illustrated that miR-30a-3p overexpression attenuated the GOLM1 facilitating impacts on LUAD progression. Finally, we proved that miR-30a-3p/GOLM1 regulated progression of LUAD cells via JAK-STAT pathway. Collectively, the inhibitory impacts of miR-30a-3p on LUAD growth may be mediated by GOLM1/JAK-STAT, which may contribute to the diagnosis of LUAD therapy and the development of therapeutic tools.
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Affiliation(s)
- Dongxiao Ding
- Department of Thoracic Surgery, The People's Hospital of Beilun District (Beilun Branch of the First Affiliated Hospital of Medical College of Zhejiang University), No.1288, East Lushan Road, Xinqi Sub-District, Beilun District, Zhejiang Province, Ningbo City, 315800, China
| | - Yunqiang Zhang
- Department of Thoracic Surgery, The People's Hospital of Beilun District (Beilun Branch of the First Affiliated Hospital of Medical College of Zhejiang University), No.1288, East Lushan Road, Xinqi Sub-District, Beilun District, Zhejiang Province, Ningbo City, 315800, China
| | - Xuede Zhang
- Department of Thoracic Surgery, The People's Hospital of Beilun District (Beilun Branch of the First Affiliated Hospital of Medical College of Zhejiang University), No.1288, East Lushan Road, Xinqi Sub-District, Beilun District, Zhejiang Province, Ningbo City, 315800, China
| | - Ke Shi
- Department of Thoracic Surgery, The People's Hospital of Beilun District (Beilun Branch of the First Affiliated Hospital of Medical College of Zhejiang University), No.1288, East Lushan Road, Xinqi Sub-District, Beilun District, Zhejiang Province, Ningbo City, 315800, China
| | - Wenjun Shang
- Department of Thoracic Surgery, The People's Hospital of Beilun District (Beilun Branch of the First Affiliated Hospital of Medical College of Zhejiang University), No.1288, East Lushan Road, Xinqi Sub-District, Beilun District, Zhejiang Province, Ningbo City, 315800, China
| | - Junjie Ying
- Department of Thoracic Surgery, The People's Hospital of Beilun District (Beilun Branch of the First Affiliated Hospital of Medical College of Zhejiang University), No.1288, East Lushan Road, Xinqi Sub-District, Beilun District, Zhejiang Province, Ningbo City, 315800, China
| | - Li Wang
- Department of Thoracic Surgery, The People's Hospital of Beilun District (Beilun Branch of the First Affiliated Hospital of Medical College of Zhejiang University), No.1288, East Lushan Road, Xinqi Sub-District, Beilun District, Zhejiang Province, Ningbo City, 315800, China
| | - Zhongjie Chen
- Department of Thoracic Surgery, The People's Hospital of Beilun District (Beilun Branch of the First Affiliated Hospital of Medical College of Zhejiang University), No.1288, East Lushan Road, Xinqi Sub-District, Beilun District, Zhejiang Province, Ningbo City, 315800, China
| | - Haihua Hong
- Department of Thoracic Surgery, The People's Hospital of Beilun District (Beilun Branch of the First Affiliated Hospital of Medical College of Zhejiang University), No.1288, East Lushan Road, Xinqi Sub-District, Beilun District, Zhejiang Province, Ningbo City, 315800, China.
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6
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Bannik K, Madas B, Jarke S, Sutter A, Siemeister G, Schatz C, Mumberg D, Zitzmann-Kolbe S. DNA repair inhibitors sensitize cells differently to high and low LET radiation. Sci Rep 2021; 11:23257. [PMID: 34853427 PMCID: PMC8636489 DOI: 10.1038/s41598-021-02719-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 11/15/2021] [Indexed: 11/09/2022] Open
Abstract
The aim of this study was to investigate effects of high LET α-radiation in combination with inhibitors of DDR (DNA-PK and ATM) and to compare the effect with the radiosensitizing effect of low LET X-ray radiation. The various cell lines were irradiated with α-radiation and with X-ray. Clonogenic survival, the formation of micronuclei and cell cycle distribution were studied after combining of radiation with DDR inhibitors. The inhibitors sensitized different cancer cell lines to radiation. DNA-PKi affected survival rates in combination with α-radiation in selected cell lines. The sensitization enhancement ratios were in the range of 1.6–1.85 in cancer cells. ATMi sensitized H460 cells and significantly increased the micronucleus frequency for both radiation qualities. ATMi in combination with α-radiation reduced survival of HEK293. A significantly elicited cell cycle arrest in G2/M phase after co-treatment of ATMi with α-radiation and X-ray. The most prominent treatment effect was observed in the HEK293 by combining α-radiation and inhibitions. ATMi preferentially sensitized cancer cells and normal HEK293 cells to α-radiation. DNA-PKi and ATMi can sensitize cancer cells to X-ray, but the effectiveness was dependent on cancer cells itself. α-radiation reduced proliferation in primary fibroblast without G2/M arrest.
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Affiliation(s)
- Kristina Bannik
- Pharmaceuticals Division, Bayer AG, Berlin, Germany.,, Berlin, Germany
| | | | - Sabrina Jarke
- Pharmaceuticals Division, Bayer AG, Berlin, Germany.,Nuvisan-ICB GmbH, Berlin, Germany
| | | | - Gerhard Siemeister
- Pharmaceuticals Division, Bayer AG, Berlin, Germany.,Nuvisan-ICB GmbH, Berlin, Germany
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Pouget JP, Constanzo J. Revisiting the Radiobiology of Targeted Alpha Therapy. Front Med (Lausanne) 2021; 8:692436. [PMID: 34386508 PMCID: PMC8353448 DOI: 10.3389/fmed.2021.692436] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 06/24/2021] [Indexed: 12/12/2022] Open
Abstract
Targeted alpha therapy (TAT) using alpha particle-emitting radionuclides is in the spotlight after the approval of 223RaCl2 for patients with metastatic castration-resistant prostate cancer and the development of several alpha emitter-based radiopharmaceuticals. It is acknowledged that alpha particles are highly cytotoxic because they produce complex DNA lesions. Hence, the nucleus is considered their critical target, and many studies did not report any effect in other subcellular compartments. Moreover, their physical features, including their range in tissues (<100 μm) and their linear energy transfer (50–230 keV/μm), are well-characterized. Theoretically, TAT is indicated for very small-volume, disseminated tumors (e.g., micrometastases, circulating tumor cells). Moreover, due to their high cytotoxicity, alpha particles should be preferred to beta particles and X-rays to overcome radiation resistance. However, clinical studies showed that TAT might be efficient also in quite large tumors, and biological effects have been observed also away from irradiated cells. These distant effects are called bystander effects when occurring at short distance (<1 mm), and systemic effects when occurring at much longer distance. Systemic effects implicate the immune system. These findings showed that cells can die without receiving any radiation dose, and that a more complex and integrated view of radiobiology is required. This includes the notion that the direct, bystander and systemic responses cannot be dissociated because DNA damage is intimately linked to bystander effects and immune response. Here, we provide a brief overview of the paradigms that need to be revisited.
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Affiliation(s)
- Jean-Pierre Pouget
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier (ICM), Montpellier, France
| | - Julie Constanzo
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier (ICM), Montpellier, France
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8
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Beyond DNA Repair: DNA-PKcs in Tumor Metastasis, Metabolism and Immunity. Cancers (Basel) 2020; 12:cancers12113389. [PMID: 33207636 PMCID: PMC7698146 DOI: 10.3390/cancers12113389] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/10/2020] [Accepted: 11/12/2020] [Indexed: 01/07/2023] Open
Abstract
The DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a key component of the DNA-PK complex that has a well-characterized function in the non-homologous end-joining repair of DNA double-strand breaks. Since its identification, a large body of evidence has demonstrated that DNA-PKcs is frequently overexpressed in cancer, plays a critical role in tumor development and progression, and is associated with poor prognosis of cancer patients. Intriguingly, recent studies have suggested novel functions beyond the canonical role of DNA-PKcs, which has transformed the paradigm of DNA-PKcs in tumorigenesis and has reinvigorated the interest to target DNA-PKcs for cancer treatment. In this review, we update recent advances in DNA-PKcs, in particular the emerging roles in tumor metastasis, metabolic dysregulation, and immune escape. We further discuss the possible molecular basis that underpins the pleiotropism of DNA-PKcs in cancer. Finally, we outline the biomarkers that may predict the therapeutic response to DNA-PKcs inhibitor therapy. Understanding the functional repertoire of DNA-PKcs will provide mechanistic insights of DNA-PKcs in malignancy and, more importantly, may revolutionize the design and utility of DNA-PKcs-based precision cancer therapy.
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Olofsson D, Cheng L, Fernández RB, Płódowska M, Riego ML, Akuwudike P, Lisowska H, Lundholm L, Wojcik A. Biological effectiveness of very high gamma dose rate and its implication for radiological protection. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2020; 59:451-460. [PMID: 32488310 PMCID: PMC7368856 DOI: 10.1007/s00411-020-00852-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 05/25/2020] [Indexed: 05/06/2023]
Abstract
Many experimental studies are carried out to compare biological effectiveness of high dose rate (HDR) with that of low dose rate (LDR). The rational for this is the uncertainty regarding the value of the dose rate effectiveness factor (DREF) used in radiological protection. While a LDR is defined as 0.1 mGy/min or lower, anything above that is seen as HDR. In cell and animal experiments, a dose rate around 1 Gy/min is usually used as representative for HDR. However, atomic bomb survivors, the reference cohort for radiological protection, were exposed to tens of Gy/min. The important question is whether gamma radiation delivered at very high dose rate (VHDR-several Gy/min) is more effective in inducing DNA damage than that delivered at HDR. The aim of this investigation was to compare the biological effectiveness of gamma radiation delivered at VHDR (8.25 Gy/min) with that of HDR (0.38 Gy/min or 0.79 Gy/min). Experiments were carried out with human peripheral mononuclear cells (PBMC) and the human osteosarcoma cell line U2OS. Endpoints related to DNA damage response were analysed. The results show that in PBMC, VHDR is more effective than HDR in inducing gene expression and micronuclei. In U2OS cells, the repair of 53BP1 foci was delayed after VHDR indicating a higher level of damage complexity, but no VHDR effect was observed at the level of micronuclei and clonogenic cell survival. We suggest that the DREF value may be underestimated when the biological effectiveness of HDR and LDR is compared.
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Affiliation(s)
- Dante Olofsson
- Department of Molecular Biosciences, Centre for Radiation Protection Research, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 106 91, Stockholm, Sweden
| | - Lei Cheng
- Department of Molecular Biosciences, Centre for Radiation Protection Research, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 106 91, Stockholm, Sweden
| | - Rubén Barrios Fernández
- Department of Molecular Biosciences, Centre for Radiation Protection Research, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 106 91, Stockholm, Sweden
| | - Magdalena Płódowska
- Department of Radiobiology and Immunology, Institute of Biology, Jan Kochanowski University, Kielce, Poland
| | - Milagrosa López Riego
- Department of Molecular Biosciences, Centre for Radiation Protection Research, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 106 91, Stockholm, Sweden
| | - Pamela Akuwudike
- Department of Molecular Biosciences, Centre for Radiation Protection Research, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 106 91, Stockholm, Sweden
| | - Halina Lisowska
- Department of Radiobiology and Immunology, Institute of Biology, Jan Kochanowski University, Kielce, Poland
| | - Lovisa Lundholm
- Department of Molecular Biosciences, Centre for Radiation Protection Research, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 106 91, Stockholm, Sweden
| | - Andrzej Wojcik
- Department of Molecular Biosciences, Centre for Radiation Protection Research, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 106 91, Stockholm, Sweden.
- Department of Radiobiology and Immunology, Institute of Biology, Jan Kochanowski University, Kielce, Poland.
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