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Oba M, Taguchi M, Kudo Y, Yamashita K, Yasui H, Matsumoto S, Kirilyuk IA, Inanami O, Hirata H. Partial Acquisition of Spectral Projections Accelerates Four-dimensional Spectral-spatial EPR Imaging for Mouse Tumor Models: A Feasibility Study. Mol Imaging Biol 2024:10.1007/s11307-024-01924-y. [PMID: 38811467 DOI: 10.1007/s11307-024-01924-y] [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: 03/26/2024] [Revised: 05/16/2024] [Accepted: 05/20/2024] [Indexed: 05/31/2024]
Abstract
PURPOSE Our study aimed to accelerate the acquisition of four-dimensional (4D) spectral-spatial electron paramagnetic resonance (EPR) imaging for mouse tumor models. This advancement in EPR imaging should reduce the acquisition time of spectroscopic mapping while reducing quality degradation for mouse tumor models. PROCEDURES EPR spectra under magnetic field gradients, called spectral projections, were partially measured. Additional spectral projections were later computationally synthesized from the measured spectral projections. Four-dimensional spectral-spatial images were reconstructed from the post-processed spectral projections using the algebraic reconstruction technique (ART) and assessed in terms of their image qualities. We applied this approach to a sample solution and a mouse Hs766T xenograft model of human-derived pancreatic ductal adenocarcinoma cells to demonstrate the feasibility of our concept. The nitroxyl radical imaging agent 2H,15N-DCP was exogenously infused into the mouse xenograft model. RESULTS The computation code of 4D spectral-spatial imaging was tested with numerically generated spectral projections. In the linewidth mapping of the sample solution, we achieved a relative standard uncertainty (standard deviation/| mean |) of 0.76 μT/45.38 μT = 0.017 on the peak-to-peak first-derivative EPR linewidth. The qualities of the linewidth maps and the effect of computational synthesis of spectral projections were examined. Finally, we obtained the three-dimensional linewidth map of 2H,15N-DCP in a Hs766T tumor-bearing leg in vivo. CONCLUSION We achieved a 46.7% reduction in the acquisition time of 4D spectral-spatial EPR imaging without significantly degrading the image quality. A combination of ART and partial acquisition in three-dimensional raster magnetic field gradient settings in orthogonal coordinates is a novel approach. Our approach to 4D spectral-spatial EPR imaging can be applied to any subject, especially for samples with less variation in one direction.
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Affiliation(s)
- Misa Oba
- Division of Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University, North 14, West 9, Kita-ku, Sapporo, 060-0814, Japan
| | - Mai Taguchi
- Division of Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University, North 14, West 9, Kita-ku, Sapporo, 060-0814, Japan
| | - Yohei Kudo
- Division of Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University, North 14, West 9, Kita-ku, Sapporo, 060-0814, Japan
| | - Koya Yamashita
- Laboratory of Radiation Biology, Graduate School of Veterinary Medicine, Hokkaido University, North 18, West 9, Kita-ku, Sapporo, 060-0818, Japan
| | - Hironobu Yasui
- Laboratory of Radiation Biology, Faculty of Veterinary Medicine, Hokkaido University, North 18, West 9, Kita-ku, Sapporo, 060-0818, Japan
| | - Shingo Matsumoto
- Division of Bioengineering and Bioinformatics, Faculty of Information Science and Technology, Hokkaido University, North 14, West 9, Kita-ku, Sapporo, 060-0814, Japan
| | - Igor A Kirilyuk
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, 9, Ac. Lavrentieva Ave, Novosibirsk, 630090, Russia
| | - Osamu Inanami
- Laboratory of Radiation Biology, Faculty of Veterinary Medicine, Hokkaido University, North 18, West 9, Kita-ku, Sapporo, 060-0818, Japan
| | - Hiroshi Hirata
- Division of Bioengineering and Bioinformatics, Faculty of Information Science and Technology, Hokkaido University, North 14, West 9, Kita-ku, Sapporo, 060-0814, Japan.
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Buyse C, Mignion L, Joudiou N, Melloul S, Driesschaert B, Gallez B. Sensitive simultaneous measurements of oxygenation and extracellular pH by EPR using a stable monophosphonated trityl radical and lithium phthalocyanine. Free Radic Biol Med 2024; 213:11-18. [PMID: 38218552 PMCID: PMC10923140 DOI: 10.1016/j.freeradbiomed.2024.01.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/09/2024] [Accepted: 01/10/2024] [Indexed: 01/15/2024]
Abstract
The monitoring of acidosis and hypoxia is crucial because both factors promote cancer progression and impact the efficacy of anti-cancer treatments. A phosphonated tetrathiatriarylmethyl (pTAM) has been previously described to monitor both parameters simultaneously, but the sensitivity to tackle subtle changes in oxygenation was limited. Here, we describe an innovative approach combining the pTAM radical and lithium phthalocyanine (LiPc) crystals to provide sensitive simultaneous measurements of extracellular pH (pHe) and pO2. Both parameters can be measured simultaneously as both EPR spectra do not overlap, with a gain in sensitivity to pO2 variations by a factor of 10. This procedure was applied to characterize the impact of carbogen breathing in a breast cancer 4T1 model as a proof-of-concept. No significant change in pHe and pO2 was observed using pTAM alone, while LiPc detected a significant increase in tumor oxygenation. Interestingly, we observed that pTAM systematically overestimated the pO2 compared to LiPc. In addition, we analyzed the impact of an inhibitor (UK-5099) of the mitochondrial pyruvate carrier (MPC) on the tumor microenvironment. In vitro, the exposure of 4T1 cells to UK-5099 for 24 h induced a decrease in pHe and oxygen consumption rate (OCR). In vivo, a significant decrease in tumor pHe was observed in UK-5099-treated mice, while there was no change for mice treated with the vehicle. Despite the change observed in OCR, no significant change in tumor oxygenation was observed after the UK-5099 treatment. This approach is promising for assessing in vivo the effect of treatments targeting tumor metabolism.
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Affiliation(s)
- Chloe Buyse
- Biomedical Magnetic Resonance Research Group (REMA), Louvain Drug Research Institute (LDRI), UCLouvain, Brussels, Belgium
| | - Lionel Mignion
- Nuclear and Electron Spin Technologies Platform (NEST), Louvain Drug Research Institute (LDRI), UCLouvain, Brussels, Belgium
| | - Nicolas Joudiou
- Nuclear and Electron Spin Technologies Platform (NEST), Louvain Drug Research Institute (LDRI), UCLouvain, Brussels, Belgium
| | - Samia Melloul
- Biomedical Magnetic Resonance Research Group (REMA), Louvain Drug Research Institute (LDRI), UCLouvain, Brussels, Belgium
| | - Benoit Driesschaert
- Department of Pharmaceutical Sciences, School of Pharmacy & In Vivo Multifunctional Magnetic Resonance Center, West Virginia University, Morgantown, WV, USA
| | - Bernard Gallez
- Biomedical Magnetic Resonance Research Group (REMA), Louvain Drug Research Institute (LDRI), UCLouvain, Brussels, Belgium.
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Spitz DR. Manipulations of Redox Metabolism for Enhancing Radiation Therapy Responses: A Historical Perspective and Novel Hypothesis. Semin Radiat Oncol 2019; 29:1-5. [PMID: 30573179 PMCID: PMC6709524 DOI: 10.1016/j.semradonc.2018.10.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Since the recognition during the 20th century that cancer cells demonstrated fundamental alterations in the regulation of oxidative and glycolytic metabolism, many basic as well as translational scientists have proposed that targeting metabolic differences in cancer versus normal cells could be exploited to improve cancer therapy outcomes. With the recognition that dysregulation of mitochondrial redox metabolism leads to the increased steady-state levels of superoxide and hydrogen peroxide which could contribute to both aging and cancer; radiation biologists have pursued many avenues of targeting oxidative metabolic pathways to both selectively radiosensitive cancer cells as well as protect normal tissues during cancer therapy. Recent advances in exploiting redox metabolism for improving radiochemotherapy both from a basic and translational science point of view are the focus of the papers in this current issue of Seminars in Radiation Oncology . The historical perspective underlying these areas of research as well as a unifying hypothesis for further advancing this research into clinical trials will be presented in this overview.
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Affiliation(s)
- Douglas R Spitz
- Free Radical and Radiation Biology Program, Department of Radiation Oncology, Free Radical Metabolism and Imaging Program, Holden Comprehensive Cancer Center, B180 Medical Laboratories, Carver College of Medicine, The University of Iowa, Iowa City, IA 52242..
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