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Shrum SA, Nukala U, Shrimali S, Pineda EN, Krager KJ, Thakkar S, Jones DE, Pathak R, Breen PJ, Aykin-Burns N, Compadre CM. Tocotrienols Provide Radioprotection to Multiple Organ Systems through Complementary Mechanisms of Antioxidant and Signaling Effects. Antioxidants (Basel) 2023; 12:1987. [PMID: 38001840 PMCID: PMC10668991 DOI: 10.3390/antiox12111987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 10/31/2023] [Accepted: 11/07/2023] [Indexed: 11/26/2023] Open
Abstract
Tocotrienols have powerful radioprotective properties in multiple organ systems and are promising candidates for development as clinically effective radiation countermeasures. To facilitate their development as clinical radiation countermeasures, it is crucial to understand the mechanisms behind their powerful multi-organ radioprotective properties. In this context, their antioxidant effects are recognized for directly preventing oxidative damage to cellular biomolecules from ionizing radiation. However, there is a growing body of evidence indicating that the radioprotective mechanism of action for tocotrienols extends beyond their antioxidant properties. This raises a new pharmacological paradigm that tocotrienols are uniquely efficacious radioprotectors due to a synergistic combination of antioxidant and other signaling effects. In this review, we have covered the wide range of multi-organ radioprotective effects observed for tocotrienols and the mechanisms underlying it. These radioprotective effects for tocotrienols can be characterized as (1) direct cytoprotective effects, characteristic of the classic antioxidant properties, and (2) other effects that modulate a wide array of critical signaling factors involved in radiation injury.
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Affiliation(s)
- Stephen A. Shrum
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
- Tocol Pharmaceuticals, LLC, Little Rock, AR 77205, USA
| | - Ujwani Nukala
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
- Joint Bioinformatics Graduate Program, University of Arkansas at Little Rock, Little Rock, AR 72204, USA
| | - Shivangi Shrimali
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
- Joint Bioinformatics Graduate Program, University of Arkansas at Little Rock, Little Rock, AR 72204, USA
| | - Edith Nathalie Pineda
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
- Joint Bioinformatics Graduate Program, University of Arkansas at Little Rock, Little Rock, AR 72204, USA
| | - Kimberly J. Krager
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Shraddha Thakkar
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Darin E. Jones
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Rupak Pathak
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Philip J. Breen
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Nukhet Aykin-Burns
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Cesar M. Compadre
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
- Tocol Pharmaceuticals, LLC, Little Rock, AR 77205, USA
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Evaluation and Management of Radiation-Induced Plexopathies. CURRENT PHYSICAL MEDICINE AND REHABILITATION REPORTS 2022. [DOI: 10.1007/s40141-022-00374-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Nuclear and Radiological Emergencies: Biological Effects, Countermeasures and Biodosimetry. Antioxidants (Basel) 2022; 11:antiox11061098. [PMID: 35739995 PMCID: PMC9219873 DOI: 10.3390/antiox11061098] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 11/17/2022] Open
Abstract
Atomic and radiological crises can be caused by accidents, military activities, terrorist assaults involving atomic installations, the explosion of nuclear devices, or the utilization of concealed radiation exposure devices. Direct damage is caused when radiation interacts directly with cellular components. Indirect effects are mainly caused by the generation of reactive oxygen species due to radiolysis of water molecules. Acute and persistent oxidative stress associates to radiation-induced biological damages. Biological impacts of atomic radiation exposure can be deterministic (in a period range a posteriori of the event and because of destructive tissue/organ harm) or stochastic (irregular, for example cell mutation related pathologies and heritable infections). Potential countermeasures according to a specific scenario require considering basic issues, e.g., the type of radiation, people directly affected and first responders, range of doses received and whether the exposure or contamination has affected the total body or is partial. This review focuses on available medical countermeasures (radioprotectors, radiomitigators, radionuclide scavengers), biodosimetry (biological and biophysical techniques that can be quantitatively correlated with the magnitude of the radiation dose received), and strategies to implement the response to an accidental radiation exposure. In the case of large-scale atomic or radiological events, the most ideal choice for triage, dose assessment and victim classification, is the utilization of global biodosimetry networks, in combination with the automation of strategies based on modular platforms.
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Watase D, Setoguchi S, Nagata-Akaho N, Goto S, Yamakawa H, Yamada A, Koga M, Karube Y, Matsunaga K, Takata J. Cationic N, N-Dimethylglycine Ester Prodrug of 2 R-α-Tocotrienol Promotes Intestinal Absorption via Efficient Self-Micellization with Intrinsic Bile Acid Anion. Molecules 2022; 27:2727. [PMID: 35566078 PMCID: PMC9102404 DOI: 10.3390/molecules27092727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 04/19/2022] [Accepted: 04/21/2022] [Indexed: 11/16/2022] Open
Abstract
The intestinal absorption of hydrophobic compounds is severely influenced by their transportation rate through the unstirred water layer in the intestinal lumen. A member of the vitamin E family, α-Tocotrienol (α-T3) has remarkable pharmacological effects, but its intestinal absorption is hampered due to its hydrophobicity. Here, we prepared three ester derivatives of 2R-α-T3, and we selected a suitable prodrug compound using rat plasma and liver microsomes. The micellization profile of the selected compound in the presence of taurocholic acid (TCA) was evaluated. After gastrostomy administration of the prodrug candidate or α-T3 solution containing TCA, AUC values were determined for α-T3 in plasma obtained from bile duct-ligated rats. Among the three types in the efficiency of the reconversion to the parent drug, α-T3 N,N-dimethylglycinate (α-T3DMG) was the best prodrug; α-T3DMG formed mixed micelles via ion pairs with anionic TCA. The solubility of α-T3DMG in n-octanol/water depended on its ratio to TCA. The AUC after α-T3DMG administration to ligated rats was 2-fold higher than that after α-T3 administration, suggesting a smooth interaction with intrinsic bile acids. In conclusion, utilization of the prodrug synthesized using N,N-dimethylglycine ester may be a beneficial approach to promote intestinal absorption of α-T3 via self-micellization with intrinsic bile acid.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Kazuhisa Matsunaga
- Faculty of Pharmaceutical Sciences, Fukuoka University, Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan; (D.W.); (S.S.); (N.N.-A.); (S.G.); (H.Y.); (A.Y.); (M.K.); (Y.K.); (J.T.)
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Badraoui R, Saeed M, Bouali N, Hamadou WS, Elkahoui S, Alam MJ, Siddiqui AJ, Adnan M, Saoudi M, Rebai T. Expression Profiling of Selected Immune Genes and Trabecular Microarchitecture in Breast Cancer Skeletal Metastases Model: Effect of α-Tocopherol Acetate Supplementation. Calcif Tissue Int 2022; 110:475-488. [PMID: 34988595 DOI: 10.1007/s00223-021-00931-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 11/18/2021] [Indexed: 01/26/2023]
Abstract
Breast cancer bone metastases (BCBM) result in serious skeletal morbidity. Although there have been important advances in cancer treatment methods such as surgery and chemotherapy, the complementary treatments, such as α-tocopherol acetate (ATA), still remain of key role via complementary and/or synergistic effects. The aim of this work was to study immune response in a rat model of BCBM due to Walker 256/B cells inoculation and the effect of ATA alone. Compared to the control group (CTRL), rat injected with Walker 256/B cells (5 × 104) in the medullar cavity (W256 group) showed osteolytic damages with marked tumor osteolysis of both cancellous and trabecular bone as assessed by X-ray radiology, micro-computed tomography, and histology. Rats inoculated with Walker 256/B cells and treated with ATA (45 mg/kg BW, W256ATA group) presented marked less tumor osteolysis, less disturbance of Tb.Th and Tb.Sp associated with conversion of rods into plates, and increased structure model index and trabecular pattern factor (Tb.Pf). Elsewhere, 3D frequency distributions of Tb.Th and Tb.Sp were highly disturbed in metastatic W256 rats. Overexpression of some genes commonly associated with cancer and metastatic proliferation: COX-2, TNF-α, and pro-inflammatory interleukins 1 and 6 was outlined. ATA alleviated most of the Walker 256/B cells-induced microarchitectural changes in the target parameters without turning back to normal levels. Likewise, it alleviates the BCSM-induced overexpression of COX-2, TNF-α, IL-1, and IL-6. In silico approach showed that ATA bound these proteins with high affinities, which satisfactory explain its beneficial effects. In conclusion, BCBM is associated with bone microarchitectural disorders and an immune response characterized by an overexpression of some key role genes in cancer proliferation and invasion. ATA exerted favorable effects on trabecular bone distribution and morphology, which may involve the COX-2, TNF-α, and ILs pathways.
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Affiliation(s)
- Riadh Badraoui
- Laboratory of General Biology, Department of Biology, University of Ha'il, Ha'il, 81451, Saudi Arabia.
- Section of Histology-Cytology, Medicine Faculty of Tunis, University of Tunis El Manar, La Rabta, 1007, Tunis, Tunisia.
- Laboratory of Histo-Embryology and Cytogenetics, Medicine Faculty of Sfax, University of Sfax, 3029, Sfax, Tunisia.
| | - Mohd Saeed
- Laboratory of General Biology, Department of Biology, University of Ha'il, Ha'il, 81451, Saudi Arabia
| | - Nouha Bouali
- Laboratory of General Biology, Department of Biology, University of Ha'il, Ha'il, 81451, Saudi Arabia
- Research Unit "Biologie Moléculaire Des Leucémies Et Lymphomes", Laboratory of Biochemistry, Medicine Faculty of Sousse University, 4002, Sousse, Tunisia
| | - Walid S Hamadou
- Laboratory of General Biology, Department of Biology, University of Ha'il, Ha'il, 81451, Saudi Arabia
- Research Unit "Biologie Moléculaire Des Leucémies Et Lymphomes", Laboratory of Biochemistry, Medicine Faculty of Sousse University, 4002, Sousse, Tunisia
| | - Salem Elkahoui
- Laboratory of General Biology, Department of Biology, University of Ha'il, Ha'il, 81451, Saudi Arabia
- Laboratory of Bioactive Substances, Center of Biotechnology of Borj Cedria (CBBC), 2050, Hammam-Lif, Tunisia
| | - Mohammad J Alam
- Laboratory of General Biology, Department of Biology, University of Ha'il, Ha'il, 81451, Saudi Arabia
| | - Arif J Siddiqui
- Laboratory of General Biology, Department of Biology, University of Ha'il, Ha'il, 81451, Saudi Arabia
| | - Mohd Adnan
- Laboratory of General Biology, Department of Biology, University of Ha'il, Ha'il, 81451, Saudi Arabia
| | - Mongi Saoudi
- Laboratory Animal Physiology, Department of Biology, College of Science, University of Sfax, 3045, Sfax, Tunisia
| | - Tarek Rebai
- Laboratory of Histo-Embryology and Cytogenetics, Medicine Faculty of Sfax, University of Sfax, 3029, Sfax, Tunisia
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Petronek MS, Stolwijk JM, Murray SD, Steinbach EJ, Zakharia Y, Buettner GR, Spitz DR, Allen BG. Utilization of redox modulating small molecules that selectively act as pro-oxidants in cancer cells to open a therapeutic window for improving cancer therapy. Redox Biol 2021; 42:101864. [PMID: 33485837 PMCID: PMC8113052 DOI: 10.1016/j.redox.2021.101864] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 01/08/2021] [Accepted: 01/10/2021] [Indexed: 02/07/2023] Open
Abstract
There is a rapidly growing body of literature supporting the notion that differential oxidative metabolism in cancer versus normal cells represents a metabolic frailty that can be exploited to open a therapeutic window into cancer therapy. These cancer cell-specific metabolic frailties may be amenable to manipulation with non-toxic small molecule redox active compounds traditionally thought to be antioxidants. In this review we describe the potential mechanisms and clinical applicability in cancer therapy of four small molecule redox active agents: melatonin, vitamin E, selenium, and vitamin C. Each has shown the potential to have pro-oxidant effects in cancer cells while retaining antioxidant activity in normal cells. This dichotomy can be exploited to improve responses to radiation and chemotherapy by opening a therapeutic window based on a testable biochemical rationale amenable to confirmation with biomarker studies during clinical trials. Thus, the unique pro-oxidant/antioxidant properties of melatonin, vitamin E, selenium, and vitamin C have the potential to act as effective adjuvants to traditional cancer therapies, thereby improving cancer patient outcomes.
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Affiliation(s)
- M S Petronek
- Department of Radiation Oncology, University of Iowa, Iowa City, IA, USA
| | - J M Stolwijk
- Department of Radiation Oncology, University of Iowa, Iowa City, IA, USA
| | - S D Murray
- Department of Cancer Biology, University of Iowa, Iowa City, IA, USA
| | - E J Steinbach
- Department of Radiation Oncology, University of Iowa, Iowa City, IA, USA
| | - Y Zakharia
- Division of Hematology and Oncology, Department of Internal Medicine, University of Iowa, Iowa City, IA, USA
| | - G R Buettner
- Department of Radiation Oncology, University of Iowa, Iowa City, IA, USA
| | - D R Spitz
- Department of Radiation Oncology, University of Iowa, Iowa City, IA, USA
| | - B G Allen
- Department of Radiation Oncology, University of Iowa, Iowa City, IA, USA.
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Nickoloff JA, Taylor L, Sharma N, Kato TA. Exploiting DNA repair pathways for tumor sensitization, mitigation of resistance, and normal tissue protection in radiotherapy. CANCER DRUG RESISTANCE (ALHAMBRA, CALIF.) 2021; 4:244-263. [PMID: 34337349 PMCID: PMC8323830 DOI: 10.20517/cdr.2020.89] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
More than half of cancer patients are treated with radiotherapy, which kills tumor cells by directly and indirectly inducing DNA damage, including cytotoxic DNA double-strand breaks (DSBs). Tumor cells respond to these threats by activating a complex signaling network termed the DNA damage response (DDR). The DDR arrests the cell cycle, upregulates DNA repair, and triggers apoptosis when damage is excessive. The DDR signaling and DNA repair pathways are fertile terrain for therapeutic intervention. This review highlights strategies to improve therapeutic gain by targeting DDR and DNA repair pathways to radiosensitize tumor cells, overcome intrinsic and acquired tumor radioresistance, and protect normal tissue. Many biological and environmental factors determine tumor and normal cell responses to ionizing radiation and genotoxic chemotherapeutics. These include cell type and cell cycle phase distribution; tissue/tumor microenvironment and oxygen levels; DNA damage load and quality; DNA repair capacity; and susceptibility to apoptosis or other active or passive cell death pathways. We provide an overview of radiobiological parameters associated with X-ray, proton, and carbon ion radiotherapy; DNA repair and DNA damage signaling pathways; and other factors that regulate tumor and normal cell responses to radiation. We then focus on recent studies exploiting DSB repair pathways to enhance radiotherapy therapeutic gain.
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Affiliation(s)
- Jac A. Nickoloff
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
- Correspondence Address: Dr. Jac A. Nickoloff, Department of Environmental and Radiological Health Sciences, Colorado State University, 1681 Campus Delivery, Ft. Collins, CO 80523-1681, USA. E-mail:
| | - Lynn Taylor
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
| | - Neelam Sharma
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
| | - Takamitsu A. Kato
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
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Neoadjuvant Radiotherapy-Related Wound Morbidity in Soft Tissue Sarcoma: Perspectives for Radioprotective Agents. Cancers (Basel) 2020; 12:cancers12082258. [PMID: 32806601 PMCID: PMC7465163 DOI: 10.3390/cancers12082258] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/10/2020] [Accepted: 08/10/2020] [Indexed: 12/18/2022] Open
Abstract
Historically, patients with localized soft tissue sarcomas (STS) of the extremities would undergo limb amputation. It was subsequently determined that the addition of radiation therapy (RT) delivered prior to (neoadjuvant) or after (adjuvant) a limb-sparing surgical resection yielded equivalent survival outcomes to amputation in appropriate patients. Generally, neoadjuvant radiation offers decreased volume and dose of high-intensity radiation to normal tissue and increased chance of achieving negative surgical margins-but also increases wound healing complications when compared to adjuvant radiotherapy. This review elaborates on the current neoadjuvant/adjuvant RT approaches, wound healing complications in STS, and the potential application of novel radioprotective agents to minimize radiation-induced normal tissue toxicity.
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Muschel RJ, Hammond EM, Dewhirst MW. A New Assay to Measure Intestinal Crypt Survival after Irradiation: Challenges and Opportunities. Cancer Res 2020; 80:927-928. [PMID: 32122905 DOI: 10.1158/0008-5472.can-19-4045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 01/02/2020] [Indexed: 11/16/2022]
Abstract
Radiotherapy is a critical component of many current, curative cancer treatments, yet it is accompanied by unavoidable irradiation of normal tissues. Abdominal and pelvic radiation almost always results in some dose delivered to the bowel with deleterious effects to the small and large intestines. While the likelihood of enteritis is dose dependent, there is also considerable variation between patients in both the extent of symptoms of enteritis as well as their duration. In this article, Martin and colleagues hypothesized that the radiation sensitivity of intestinal organoids could predict the sensitivity of individual patients to enteritis and have taken the first steps to develop such an assay.See related article by Martin et al., p. 1219.
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Affiliation(s)
- Ruth J Muschel
- Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom.
| | - Ester M Hammond
- Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Mark W Dewhirst
- Department of Radiation Oncology, Duke University, Durham, North Carolina
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Vitamin E and cancer: an update on the emerging role of γ and δ tocotrienols. Eur J Nutr 2019; 59:845-857. [PMID: 31016386 DOI: 10.1007/s00394-019-01962-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 04/01/2019] [Indexed: 02/07/2023]
Abstract
Despite significant advances in the diagnosis and treatment of cancer, the latter still remains a fatal disease due to the lack of prevention, early diagnosis, and effective drugs. Radiotherapy, chemotherapy, and surgery are not only expensive but produce a number of side effects that are detrimental to the patients' quality of life. Therefore, there is a great need to discover anti-cancer therapies that are specific to cancer cells and affordable, safe, and well tolerated by the patients. Vitamin E is a potential candidate due to its safety. Accumulating evidence on the anti-cancer potency of vitamin E has shifted the focus from tocopherols (TOCs) to tocotrienols (TTs). γ-TT and δ-TT have the highest anti-cancer activities and target common molecular pathways involved in the inhibition of the cell cycle, the induction of apoptosis and autophagy, and the inhibition of invasion, metastasis, and angiogenesis. Future directions should focus on further investigating how γ-TT and δ-TT (solely or in combination) induce anti-cancer molecular pathways when used in the presence of conventional chemotherapeutic drugs. These studies should be carried out in vitro, and promising results and combinations should then be assessed in in vivo experiments and finally in clinical trials. Finally, future research should focus on further evaluating the roles of γ-TT and δ-TT in the chemoprevention of cancer.
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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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