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Jiang Q. Different Roles of Tocopherols and Tocotrienols in Chemoprevention and Treatment of Prostate Cancer. Adv Nutr 2024; 15:100240. [PMID: 38734077 PMCID: PMC11215218 DOI: 10.1016/j.advnut.2024.100240] [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: 12/08/2023] [Revised: 03/29/2024] [Accepted: 04/30/2024] [Indexed: 05/13/2024] Open
Abstract
The vitamin E family contains α-tocopherol (αT), βT, γT, and δT and α-tocotrienol (TE), βTE, γTE, and δTE. Research has revealed distinct roles of these vitamin E forms in prostate cancer (PCa). The ATBC trial showed that αT at a modest dose significantly decreased PCa mortality among heavy smokers. However, other randomized controlled trials including the Selenium and Vitamin E Cancer Prevention Trial (SELECT) indicate that supplementation of high-dose αT (≥400 IU) does not prevent PCa among nonsmokers. Preclinical cell and animal studies also do not support chemopreventive roles of high-dose αT and offer explanations for increased incidence of early-stage PCa reported in the SELECT. In contrast, accumulating animal studies have demonstrated that γT, δT, γTE, and δTE appear to be effective for preventing early-stage PCa from progression to adenocarcinoma in various PCa models. Existing evidence also support therapeutic roles of γTE and its related combinations against advanced PCa. Mechanistic and cell-based studies show that different forms of vitamin E display varied efficacy, that is, δTE ≥ γTE > δT ≥ γT >> αT, in inhibiting cancer hallmarks and enabling characteristics, including uncontrolled cell proliferation, angiogenesis, and inflammation possibly via blocking 5-lipoxygenase, nuclear factor κB, hypoxia-inducible factor-1α, modulating sphingolipids, and targeting PCa stem cells. Overall, existing evidence suggests that modest αT supplement may be beneficial to smokers and γT, δT, γTE, and δTE are promising agents for PCa prevention for modest-risk to relatively high-risk population. Despite encouraging preclinical evidence, clinical research testing γT, δT, γTE, and δTE for PCa prevention is sparse and should be considered.
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Affiliation(s)
- Qing Jiang
- Department of Nutrition Science, Purdue University, West Lafayette, IN, United States.
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2
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Schlörmann W, Liao S, Dinc T, Lorkowski S, Wallert M, Glei M. Chemopreventive effects of α-tocopherol and its long-chain metabolites α-13'-hydroxy- and α-13'-carboxychromanol in LT97 colon adenoma cells. Food Funct 2024; 15:183-195. [PMID: 38019686 DOI: 10.1039/d3fo02826g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2023]
Abstract
Anticancer effects of vitamin E (tocopherols) have been studied extensively. While in vitro and animal studies showed promising results regarding anticancer effects of tocopherols, human intervention studies failed to reproduce these results. In vivo, α-tocopherol (α-TOH) is metabolized to the long-chain metabolites (LCM) 13'-hydroxychromanol (α-13'-OH) and 13'-carboxychromanol (α-13'-COOH), which likely reach the large intestine. The LCM showed antiproliferative effects in different colon cancer cell lines, but the exact mechanism of action remains unclear. To further clarify the chemopreventive action of the LCM, premalignant LT97 colon adenoma cells were treated with α-TOH, α-13'-OH and α-13'-COOH to study their impact on growth, apoptosis, antigenotoxicity, and ROS-scavenging capacity as well as expression of selected genes involved in detoxification and the cell cycle. Growth inhibitory potential was observed for α-13'-OH (IC50: 37.4 μM) and α-13'-COOH (IC50: 5.8 μM) but not for α-TOH in the tested concentrations. Levels of caspase-3 activity and expression of genes regulating the cell cycle and detoxification remained unchanged. However, α-TOH, α-13'-OH and α-13'-COOH exhibited antigenotoxic and partly ROS-scavenging capacity. The results indicate that the LCM exert chemopreventive effects via ROS-scavenging capacity, the protection against DNA damage and the induction of cell death via caspase-independent mechanisms in premalignant colon cells.
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Affiliation(s)
- Wiebke Schlörmann
- Friedrich Schiller University Jena, Institute of Nutritional Sciences, Department of Applied Nutritional Toxicology, Dornburger Str. 24, 07743 Jena, Germany.
| | - Sijia Liao
- Friedrich Schiller University Jena, Institute of Nutritional Sciences, Department of Nutritional Biochemistry and Physiology, Dornburger Str. 25, 07743 Jena, Germany
| | - Tülin Dinc
- Friedrich Schiller University Jena, Institute of Nutritional Sciences, Department of Applied Nutritional Toxicology, Dornburger Str. 24, 07743 Jena, Germany.
| | - Stefan Lorkowski
- Friedrich Schiller University Jena, Institute of Nutritional Sciences, Department of Nutritional Biochemistry and Physiology, Dornburger Str. 25, 07743 Jena, Germany
- Competence Cluster for Nutrition and Cardiovascular Health (nutriCARD), Halle-Jena-Leipzig, 07743 Jena, Germany
| | - Maria Wallert
- Friedrich Schiller University Jena, Institute of Nutritional Sciences, Department of Nutritional Biochemistry and Physiology, Dornburger Str. 25, 07743 Jena, Germany
| | - Michael Glei
- Friedrich Schiller University Jena, Institute of Nutritional Sciences, Department of Applied Nutritional Toxicology, Dornburger Str. 24, 07743 Jena, Germany.
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3
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Pang KL, Mai CW, Chin KY. Molecular Mechanism of Tocotrienol-Mediated Anticancer Properties: A Systematic Review of the Involvement of Endoplasmic Reticulum Stress and Unfolded Protein Response. Nutrients 2023; 15:nu15081854. [PMID: 37111076 PMCID: PMC10145773 DOI: 10.3390/nu15081854] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/08/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
BACKGROUND Tocotrienol, a type of vitamin E, is well known for its anti-cancer and other biological activities. This systematic review aims to summarize the involvement of endoplasmic reticulum stress (ERS) and subsequent unfolded protein response (UPR) as the underlying molecular mechanisms for the anticancer properties of tocotrienol. METHOD A comprehensive literature search was performed in March 2023 using the PubMed, Scopus, Web of Science, and EMBASE databases. In vitro, in vivo, and human studies were considered. RESULT A total of 840 articles were retrieved during the initial search, and 11 articles that fit the selection criteria were included for qualitative analysis. The current mechanistic findings are based solely on in vitro studies. Tocotrienol induces cancer cell growth arrest, autophagy, and cell death primarily through apoptosis but also through paraptosis-like cell death. Tocotrienol-rich fractions, including α-, γ- and δ-tocotrienols, induce ERS, as evidenced by upregulation of UPR markers and/or ERS-related apoptosis markers. Early endoplasmic reticulum calcium ion release, increased ceramide level, proteasomal inhibition, and upregulation of microRNA-190b were suggested to be essential in modulating tocotrienol-mediated ERS/UPR transduction. Nevertheless, the upstream molecular mechanism of tocotrienol-induced ERS is largely unknown. CONCLUSION ERS and UPR are essential in modulating tocotrienol-mediated anti-cancer effects. Further investigation is needed to elucidate the upstream molecular mechanism of tocotrienol-mediated ERS.
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Affiliation(s)
- Kok-Lun Pang
- Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia
- Newcastle University Medicine Malaysia, Iskandar Puteri 79200, Malaysia
| | - Chun-Wai Mai
- Department of Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, UCSI University, Kuala Lumpur 56000, Malaysia
| | - Kok-Yong Chin
- Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia
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4
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How vitamin E and its derivatives regulate tumour cells via the MAPK signalling pathway?'. Gene 2022; 808:145998. [PMID: 34626718 DOI: 10.1016/j.gene.2021.145998] [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: 06/29/2021] [Revised: 09/29/2021] [Accepted: 10/04/2021] [Indexed: 11/22/2022]
Abstract
In tumour cells, vitamin E and its derivatives play a critical role in the regulation of multiple signalling pathways through their oxidative and nonoxidative functions. To date, there are 8 known natural vitamin E forms and many kinds of derivatives, among which VES and α-TEA have excellent anticancer activities. The MAPK pathway consists of a complex cascade of proteins that control the proliferation, differentiation and apoptosis of tumour cells. The MAPK pathway includes four subfamilies, ERK1/2, JNK1/2, p38 MAPK, and ERK5. Most of the proteins in these subfamilies interact with each other in a complex manner. The anticancer function of vitamin E and its derivatives is closely related to the MAPK cascade. Studies have shown that in tumour cells, α-T/γ-T/γ-T3/δ-T3/VES/α-TEA regulated ERK1/2, prevent tumorigenesis, inhibit tumour cell growth and metastasis and induce cell differentiation, apoptosis, and cell cycle arrest; γ-T3/δ-T3/VES/α-TEA regulates JNK1/2, induce apoptosis, reduce ceramide synthesis and inhibit proliferation; and γ-T3/δ-T3/VES regulate p38 MAPK and induce apoptosis. This paper reviews the role of vitamin E and its derivatives in the MAPK cascade, and tumour cells are used as a model in an attempt to explore the mechanism of their interactions.
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Jiang Q, Im S, Wagner JG, Hernandez ML, Peden DB. Gamma-tocopherol, a major form of vitamin E in diets: Insights into antioxidant and anti-inflammatory effects, mechanisms, and roles in disease management. Free Radic Biol Med 2022; 178:347-359. [PMID: 34896589 PMCID: PMC8826491 DOI: 10.1016/j.freeradbiomed.2021.12.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 11/14/2021] [Accepted: 12/07/2021] [Indexed: 01/03/2023]
Abstract
γ-Tocopherol (γT) is a major form of vitamin E in the US diet and the second most abundant vitamin E in the blood and tissues, while α-tocopherol (αT) is the predominant vitamin E in tissues. During the last >25 years, research has revealed that γT has unique antioxidant and anti-inflammatory activities relevant to disease prevention compared to αT. While both compounds are potent lipophilic antioxidants, γT but not αT can trap reactive nitrogen species by forming 5-nitro-γT, and appears to show superior protection of mitochondrial function. γT inhibits ionophore-stimulated leukotrienes by blocking 5-lipoxygenase (5-LOX) translocation in leukocytes, decreases cyclooxygenase-2 (COX-2)-catalyzed prostaglandins in macrophages and blocks the growth of cancer cells but not healthy cells. For these activities, γT is stronger than αT. Moreover, γT is more extensively metabolized than αT via cytochrome P-450 (CYP4F2)-initiated side-chain oxidation, which leads to formation of metabolites including 13'-carboxychromanol (13'-COOH) and carboxyethyl-hydroxychroman (γ-CEHC). 13'-COOH and γ-CEHC are shown to be the predominant metabolites found in feces and urine, respectively. Interestingly, γ-CEHC has natriuretic activity and 13'-COOH inhibits both COX-1/-2 and 5-LOX activity. Consistent with these mechanistic findings of γT and metabolites, studies show that supplementation of γT mitigates inflammation and disease symptoms in animal models with induced inflammation, asthma and cancer. In addition, supplementation of γT decreased inflammation markers in patients with kidney diseases and mild asthma. These observations support that γT may be useful against inflammation-associated diseases.
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Affiliation(s)
- Qing Jiang
- Department of Nutrition Science, Purdue University, IN, 47907, West Lafayette, USA.
| | - Suji Im
- Department of Nutrition Science, Purdue University, IN, 47907, West Lafayette, USA
| | - James G Wagner
- Department of Pathobiology and Diagnostic Investigation, Michigan State University, USA
| | - Michelle L Hernandez
- Division of Allergy & Immunology, University of North Carolina School of Medicine, USA
| | - David B Peden
- Division of Allergy & Immunology, University of North Carolina School of Medicine, USA
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Kitazume T, Gan N, Yusa S, Ooya T. Role of Hydrophilic Monomers in
α
‐Tocopherol‐Based Copolymers in Causing Cell Death by ROS Production. MACROMOL CHEM PHYS 2021. [DOI: 10.1002/macp.202100099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Takuya Kitazume
- Department of Chemical Science and Engineering Graduate School of Engineering Kobe University 1‐1 Rokkoudaicho Nada‐ku Kobe Hyogo 657‐8501 Japan
| | - Ning Gan
- Department of Chemical Science and Engineering Graduate School of Engineering Kobe University 1‐1 Rokkoudaicho Nada‐ku Kobe Hyogo 657‐8501 Japan
| | - Shin‐Ichi Yusa
- Graduate School of Engineering University of Hyogo 2167 Shosha Himeji Hyogo 671‐2280 Japan
| | - Tooru Ooya
- Department of Chemical Science and Engineering Graduate School of Engineering Kobe University 1‐1 Rokkoudaicho Nada‐ku Kobe Hyogo 657‐8501 Japan
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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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Figueroa Gonzalez D, Young F. Gamma Tocopherol Reduced Chemotherapeutic-Induced ROS in an Ovarian Granulosa Cell Line, But Not in Breast Cancer Cell Lines In Vitro. Antioxidants (Basel) 2020; 9:antiox9010051. [PMID: 31936058 PMCID: PMC7023168 DOI: 10.3390/antiox9010051] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/30/2019] [Accepted: 12/31/2019] [Indexed: 01/13/2023] Open
Abstract
Doxorubicin and cyclophosphamide are used to treat breast cancer, but they also cause infertility through off-target cytotoxicity towards proliferating granulosa cells that surround eggs. Each chemotherapeutic generates reactive oxygen species (ROS) but the effects of the combination, or the antioxidants alpha (αToc) and gamma tocopherol (γToc) on ROS in breast cancer or ovarian cells are unknown. Human breast cancer (MCF7, T47D) and ovarian cancer (OVCAR, COV434) cells were loaded with DCDFA and exposed (1, 2, 3, 24 h) to the MCF7-derived EC25 values of individual agents, or to combinations of these. ROS were quantified and viable cells enumerated using crystal violet or DAPI. Each chemotherapeutic killed ~25% of MCF7, T47D and OVCAR cells, but 57 ± 2% (doxorubicin) and 66 ± 2% (cyclophosphamide) of the COV434 granulosa cells. The combined chemotherapeutics decreased COV434 cell viability to 34 ± 5% of control whereas doxorubicin + cyclophosphamide + γToc reduced ROS within 3 h (p < 0.01) and reduced cytotoxicity to 54 ± 4% (p < 0.05). αToc was not cytotoxic, whereas γToc killed ~25% of the breast cancer but none of the ovarian cells. Adding γToc to the combined chemotherapeutics did not change ROS or cytotoxicity in MCF7, T47D or OVCAR cells. The protection γToc afforded COV434 granulosa cells against chemotherapy-induced ROS and cytotoxicity suggests potential for fertility preservation.
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9
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Jiang Q. Natural forms of vitamin E and metabolites-regulation of cancer cell death and underlying mechanisms. IUBMB Life 2018; 71:495-506. [PMID: 30548200 DOI: 10.1002/iub.1978] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/17/2018] [Accepted: 11/02/2018] [Indexed: 12/25/2022]
Abstract
The disappointing results from large clinical studies of α-tocopherol (αT), the major form of vitamin E in tissues, for prevention of chronic diseases including cancer have cast doubt on not only αT but also other forms of vitamin E regarding their role in preventing carcinogenesis. However, basic research has shown that specific forms of vitamin E such as γ-tocopherol (γT), δ-tocopherol (δT), γ-tocotrienol (γTE) and δ-tocotrienol (δTE) can inhibit the growth and induce death of many types of cancer cells, and are capable of suppressing cancer development in preclinical cancer models. For these activities, these vitamin E forms are much stronger than αT. Further, recent research revealed novel anti-inflammatory and anticancer effects of vitamin E metabolites including 13'-carboxychromanols. This review focuses on anti-proliferation and induction of death in cancer cells by vitamin E forms and metabolites, and discuss mechanisms underlying these anticancer activities. The existing in vitro and in vivo evidence indicates that γT, δT, tocotrienols and 13'-carboxychromanols have anti-cancer activities via modulating key signaling or mediators that regulate cell death and tumor progression, such as eicosanoids, NF-κB, STAT3, PI3K, and sphingolipid metabolism. These results provide useful scientific rationales and mechanistic understanding for further translation of basic discoveries to the clinic with respect to potential use of these vitamin E forms and metabolites for cancer prevention and therapy. © 2018 IUBMB Life, 71(4):495-506, 2019.
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Affiliation(s)
- Qing Jiang
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana, 47907, USA
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10
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Vitamin E δ-tocotrienol inhibits TNF-α-stimulated NF-κB activation by up-regulation of anti-inflammatory A20 via modulation of sphingolipid including elevation of intracellular dihydroceramides. J Nutr Biochem 2018; 64:101-109. [PMID: 30471562 DOI: 10.1016/j.jnutbio.2018.10.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 09/30/2018] [Accepted: 10/29/2018] [Indexed: 12/24/2022]
Abstract
Nuclear factor-κB (NF-κB) regulates inflammation and cell survival, and is considered a potential target for anti-inflammatory and anti-cancer therapy. δ-Tocotrienol (δTE), a vitamin E form, has been shown to inhibit NF-κB, but the mechanism underlying this action is not clear. In the present study, we show that δTE inhibited TNF-α-induced activation of NF-κB and LPS-stimulated IL-6 in a dose- and time-dependent manner in Raw 264.7 macrophages. δTE potently inhibited TNF-α-induced phosphorylation of transforming growth factor β-activated kinase 1 (TAK1), an upstream kinase essential for the activation of NF-κB. Interestingly, δTE significantly increased the expression of A20 and to a less extent, cylindromatosis (CYLD), both of which are inhibitors of NF-κB. The importance of induction of A20 in δTE's anti-NF-κB effect is validated in A20 knockout cells where δTE's inhibition of NF-κB was largely diminished. In pursuit of the cause for A20 induction, we found that δTE treatment caused rapid and persistent elevation of dihydroceramides, while decreased ceramides initially but increased ceramides during prolonged treatment. These changes of sphingolipids were accompanied by increased cellular stress markers. Importantly, δTE's induction of A20 and inhibition of NF-κB activation were partially counteracted by myriocin, a potent inhibitor of de novo synthesis of sphingolipids, indicating a critical role of sphingolipid modulation in δTE-mediated effects. Since dihydroceramide has been shown to induce A20 and inhibit NF-κB in RAW cells, we conclude that that δTE inhibits NF-κB activation by enhancing its negative regulator A20 as a result of modulating sphingolipids especially elevation of dihydroceramides.
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11
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Tocotrienols: The promising analogues of vitamin E for cancer therapeutics. Pharmacol Res 2018; 130:259-272. [DOI: 10.1016/j.phrs.2018.02.017] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 02/06/2018] [Accepted: 02/12/2018] [Indexed: 12/16/2022]
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Abstract
Initial research on vitamin E and cancer has focused on α-tocopherol (αT), but recent clinical studies on cancer-preventive effects of αT supplementation have shown disappointing results, which has led to doubts about the role of vitamin E, including different vitamin E forms, in cancer prevention. However, accumulating mechanistic and preclinical animal studies show that other forms of vitamin E, such as γ-tocopherol (γT), δ-tocopherol (δT), γ-tocotrienol (γTE), and δ-tocotrienol (δTE), have far superior cancer-preventive activities than does αT. These vitamin E forms are much stronger than αT in inhibiting multiple cancer-promoting pathways, including cyclo-oxygenase (COX)- and 5-lipoxygenase (5-LOX)-catalyzed eicosanoids, and transcription factors such as nuclear transcription factor κB (NF-κB) and signal transducer and activator of transcription factor 3 (STAT3). These vitamin E forms, but not αT, cause pro-death or antiproliferation effects in cancer cells via modulating various signaling pathways, including sphingolipid metabolism. Unlike αT, these vitamin E forms are quickly metabolized to various carboxychromanols including 13'-carboxychromanols, which have even stronger anti-inflammatory and anticancer effects than some vitamin precursors. Consistent with mechanistic findings, γT, δT, γTE, and δTE, but not αT, have been shown to be effective for preventing the progression of various types of cancer in preclinical animal models. This review focuses on cancer-preventive effects and mechanisms of γT, δT, γTE, and δTE in cells and preclinical models and discusses current progress in clinical trials. The existing evidence strongly indicates that these lesser-known vitamin E forms are effective agents for cancer prevention or as adjuvants for improving prevention, therapy, and control of cancer.
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Affiliation(s)
- Qing Jiang
- Department of Nutrition Science, Purdue University, West Lafayette, IN
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13
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Abstract
Four tocopherols are available in nature and are absorbed with the diet, but only one RRR-α-tocopherol satisfies the criteria of being a vitamin. The biological activity of the different tocopherols studied in the rat by the resorption-gestation test has been inconsistently extrapolated to human beings where the tocopherols have no influence on a successful pregnancy. Diminution of RRR-α-tocopherol intake results in diseases characterized by ataxia, whose pathogenetic mechanism, despite vigorous claims, has not been clarified. The calculation of the Daily Reference Intake (DRI), necessary to prevent disease, is based on an obsolete test, the peroxide-induced erythrocyte hemolysis, called the gold standard, but of highly questioned validity. If many epidemiological studies have given positive results, showing prevention by high vitamin E containing diets of cardiovascular events, neurodegenerative disease, macular degeneration and cancer, the clinical confirmatory intervention studies were mostly negative. On the positive side, besides preventing vitamin E deficiency diseases, vitamin E has shown efficacy as anti-inflammatory and immune boosting compound. It has also shown some efficacy in protecting against nonalcoholic hepato-steatosis. At a molecular level, vitamin E and some of its metabolites have shown capacity of regulating cell signaling and modulating gene transcription.
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Affiliation(s)
- Angelo Azzi
- Vascular Biology Laboratory, JM USDA-HNRCA at Tufts University, Boston, MA 02111, USA.
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14
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Jang Y, Rao X, Jiang Q. Gamma-tocotrienol profoundly alters sphingolipids in cancer cells by inhibition of dihydroceramide desaturase and possibly activation of sphingolipid hydrolysis during prolonged treatment. J Nutr Biochem 2017; 46:49-56. [PMID: 28456081 DOI: 10.1016/j.jnutbio.2017.04.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 03/11/2017] [Accepted: 04/06/2017] [Indexed: 01/10/2023]
Abstract
Vitamin E gamma-tocotrienol (γTE) is known to have anticancer effects, but mechanisms underlying these actions are not clear. Here using liquid chromatography tandem mass spectrometry, we show that γTE induced marked changes of sphingolipids including rapid elevation of dihydrosphingosine and dihydroceramides (dhCers) in various types of cancer cells. The elevation of dihydrosphingolipids coincided with increased cellular stress, as indicated by JNK phosphorylation, and was prior to any sign of induction of apoptosis. Chemically blocking de novo synthesis of sphingolipids partially counteracted γTE-induced apoptosis and autophagy. Experiments using 13C3, 15N-labeled l-serine together with enzyme assays indicate that γTE inhibited cellular dihydroceramide desaturase (DEGS) activity without affecting its protein expression or de novo synthesis of sphingolipids. Unlike the effect on dhCers, γTE decreased ceramides (Cers) after 8-h treatment but increased C18:0-Cer and C16:0-Cer after 16 and 24 h, respectively. The increase of Cers coincides with γTE-induced apoptosis and autophagy. Since γTE inhibits DEGS and decreases de novo Cer synthesis, elevation of Cers during prolonged γTE treatment is likely caused by sphingomeylinase-mediated hydrolysis of sphingomyelin. This idea is supported by the observation that an acid sphingomeylinase inhibitor partially reversed γTE-induced cell death. Our study demonstrates that γTE altered sphingolipid metabolism by inhibiting DEGS activity and possibly by activating SM hydrolysis during prolonged treatment in cancer cells.
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Affiliation(s)
- Yumi Jang
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907
| | - Xiayu Rao
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907
| | - Qing Jiang
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907.
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15
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Galadari S, Rahman A, Pallichankandy S, Thayyullathil F. Reactive oxygen species and cancer paradox: To promote or to suppress? Free Radic Biol Med 2017; 104:144-164. [PMID: 28088622 DOI: 10.1016/j.freeradbiomed.2017.01.004] [Citation(s) in RCA: 606] [Impact Index Per Article: 86.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 12/16/2016] [Accepted: 01/03/2017] [Indexed: 02/07/2023]
Abstract
Reactive oxygen species (ROS), a group of highly reactive ions and molecules, are increasingly being appreciated as powerful signaling molecules involved in the regulation of a variety of biological processes. Indeed, their role is continuously being delineated in a variety of pathophysiological conditions. For instance, cancer cells are shown to have increased ROS levels in comparison to their normal counterparts. This is partly due to an enhanced metabolism and mitochondrial dysfunction in cancer cells. The escalated ROS generation in cancer cells contributes to the biochemical and molecular changes necessary for the tumor initiation, promotion and progression, as well as, tumor resistance to chemotherapy. Therefore, increased ROS in cancer cells may provide a unique opportunity to eliminate cancer cells via elevating ROS to highly toxic levels intracellularly, thereby, activating various ROS-induced cell death pathways, or inhibiting cancer cell resistance to chemotherapy. Such results can be achieved by using agents that either increase ROS generation, or inhibit antioxidant defense, or even a combination of both. In fact, a large variety of anticancer drugs, and some of those currently under clinical trials, effectively kill cancer cells and overcome drug resistance via enhancing ROS generation and/or impeding the antioxidant defense mechanism. This review focuses on our current understanding of the tumor promoting (tumorigenesis, angiogenesis, invasion and metastasis, and chemoresistance) and the tumor suppressive (apoptosis, autophagy, and necroptosis) functions of ROS, and highlights the potential mechanism(s) involved. It also sheds light on a very novel and an actively growing field of ROS-dependent cell death mechanism referred to as ferroptosis.
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Affiliation(s)
- Sehamuddin Galadari
- Cell Signaling Laboratory, Department of Biochemistry, College of Medicine and Health Sciences, UAE University, P.O. Box 17666, Al Ain, Abu Dhabi, UAE; Al Jalila Foundation Research Centre, P.O. Box 300100, Dubai, UAE.
| | - Anees Rahman
- Cell Signaling Laboratory, Department of Biochemistry, College of Medicine and Health Sciences, UAE University, P.O. Box 17666, Al Ain, Abu Dhabi, UAE.
| | - Siraj Pallichankandy
- Cell Signaling Laboratory, Department of Biochemistry, College of Medicine and Health Sciences, UAE University, P.O. Box 17666, Al Ain, Abu Dhabi, UAE.
| | - Faisal Thayyullathil
- Cell Signaling Laboratory, Department of Biochemistry, College of Medicine and Health Sciences, UAE University, P.O. Box 17666, Al Ain, Abu Dhabi, UAE.
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Casasampere M, Ordóñez YF, Casas J, Fabrias G. Dihydroceramide desaturase inhibitors induce autophagy via dihydroceramide-dependent and independent mechanisms. Biochim Biophys Acta Gen Subj 2016; 1861:264-275. [PMID: 27894925 DOI: 10.1016/j.bbagen.2016.11.033] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 11/10/2016] [Accepted: 11/23/2016] [Indexed: 12/25/2022]
Abstract
BACKGROUND Autophagy consists on the delivery of cytoplasmic material and organelles to lysosomes for degradation. Research on autophagy is a growing field because deciphering the basic mechanisms of autophagy is key to understanding its role in health and disease, and to paving the way to discovering novel therapeutic strategies. Studies with chemotherapeutic drugs and pharmacological tools support a role for dihydroceramides as mediators of autophagy. However, their effect on the autophagy outcome (cell survival or death) is more controversial. METHODS We have examined the capacity of structurally varied Des1 inhibitors to stimulate autophagy (LC3-II analysis), to increase dihydroceramides (mass spectrometry) and to reduce cell viability (SRB) in T98G and U87MG glioblastoma cells under different experimental conditions. RESULTS The compounds activity on autophagy induction took place concomitantly with accumulation of dihydroceramides, which occurred by both stimulation of ceramide synthesis de novo and reduction of Des1 activity. However, autophagy was also induced by the test compounds after preincubation with myriocin and in cells with a reduced capacity to produce dihydroceramides (U87DND). Autophagy inhibition with 3-methyladenine in the de novo dihydroceramide synthesis competent U87MG cells increased cytotoxicity, while genetic inhibition of autophagy in U87DND cells, poorly efficient at synthesizing dihydroceramides, augmented resistance to the test compounds. CONCLUSION Dihydroceramide desaturase 1 inhibitors activate autophagy via both dihydroceramide-dependent and independent pathways and the balance between the two pathways influences the final cell fate. GENERAL SIGNIFICANCE The cells capacity to biosynthesize dihydroceramides must be taken into account in proautophagic Des1 inhibitors-including therapies.
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Affiliation(s)
- Mireia Casasampere
- Consejo Superior de Investigaciones Científicas (CSIC), Institut de Química Avançada de Catalunya (IQAC-CSIC), Departament de Química Biomèdica, Research Unit on Bioactive Molecules (RUBAM), Jordi Girona 18-26, 08034 Barcelona, Spain
| | - Yadira F Ordóñez
- Consejo Superior de Investigaciones Científicas (CSIC), Institut de Química Avançada de Catalunya (IQAC-CSIC), Departament de Química Biomèdica, Research Unit on Bioactive Molecules (RUBAM), Jordi Girona 18-26, 08034 Barcelona, Spain
| | - Josefina Casas
- Consejo Superior de Investigaciones Científicas (CSIC), Institut de Química Avançada de Catalunya (IQAC-CSIC), Departament de Química Biomèdica, Research Unit on Bioactive Molecules (RUBAM), Jordi Girona 18-26, 08034 Barcelona, Spain
| | - Gemma Fabrias
- Consejo Superior de Investigaciones Científicas (CSIC), Institut de Química Avançada de Catalunya (IQAC-CSIC), Departament de Química Biomèdica, Research Unit on Bioactive Molecules (RUBAM), Jordi Girona 18-26, 08034 Barcelona, Spain..
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Jang Y, Park NY, Rostgaard-Hansen AL, Huang J, Jiang Q. Vitamin E metabolite 13'-carboxychromanols inhibit pro-inflammatory enzymes, induce apoptosis and autophagy in human cancer cells by modulating sphingolipids and suppress colon tumor development in mice. Free Radic Biol Med 2016; 95:190-9. [PMID: 27016075 PMCID: PMC4867259 DOI: 10.1016/j.freeradbiomed.2016.03.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 02/29/2016] [Accepted: 03/21/2016] [Indexed: 01/01/2023]
Abstract
Vitamin E forms are substantially metabolized to various carboxychromanols including 13'-carboxychromanols (13'-COOHs) that are found at high levels in feces. However, there is limited knowledge about functions of these metabolites. Here we studied δT-13'-COOH and δTE-13'-COOH, which are metabolites of δ-tocopherol and δ-tocotrienol, respectively. δTE-13'-COOH is also a natural constituent of a traditional medicine Garcinia Kola. Both 13'-COOHs are much stronger than tocopherols in inhibition of pro-inflammatory and cancer promoting cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX), and in induction of apoptosis and autophagy in colon cancer cells. The anticancer effects by 13'-COOHs appeared to be partially independent of inhibition of COX-2/5-LOX. Using liquid chromatography tandem mass spectrometry, we found that 13'-COOHs increased intracellular dihydrosphingosine and dihydroceramides after short-time incubation in HCT-116 cells, and enhanced ceramides while decreased sphingomyelins during prolonged treatment. Modulation of sphingolipids by 13'-COOHs was observed prior to or coinciding with biochemical manifestation of cell death. Pharmaceutically blocking the increase of these sphingolipids partially counteracted 13'-COOH-induced cell death. Further, 13'-COOH inhibited dihydroceramide desaturase without affecting the protein expression. In agreement with these mechanistic findings, δTE-13'-COOH significantly suppressed the growth and multiplicity of colon tumor in mice. Our study demonstrates that 13'-COOHs have anti-inflammatory and anticancer activities, may contribute to in vivo anticancer effect of vitamin E forms and are promising novel cancer prevention agents.
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Affiliation(s)
- Yumi Jang
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Na-Young Park
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | | | - Jianjie Huang
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Qing Jiang
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA.
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18
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Abstract
Studies over the past two decades have identified ceramide as a multifunctional central molecule in the sphingolipid biosynthetic pathway. Given its diverse tumor suppressive activities, molecular understanding of ceramide action will produce fundamental insights into processes that limit tumorigenesis and may identify key molecular targets for therapeutic intervention. Ceramide can be activated by a diverse array of stresses such as heat shock, genotoxic damage, oxidative stress and anticancer drugs. Ceramide triggers a variety of tumor suppressive and anti-proliferative cellular programs such as apoptosis, autophagy, senescence, and necroptosis by activating or repressing key effector molecules. Defects in ceramide generation and metabolism in cancer contribute to tumor cell survival and resistance to chemotherapy. The potent and versatile anticancer activity profile of ceramide has motivated drug development efforts to (re-)activate ceramide in established tumors. This review focuses on our current understanding of the tumor suppressive functions of ceramide and highlights the potential downstream targets of ceramide which are involved in its tumor suppressive action.
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Drotleff AM, Büsing A, Willenberg I, Empl MT, Steinberg P, Ternes W. HPLC Separation of Vitamin E and Its Oxidation Products and Effects of Oxidized Tocotrienols on the Viability of MCF-7 Breast Cancer Cells in Vitro. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:8930-8939. [PMID: 26405759 DOI: 10.1021/acs.jafc.5b04388] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Tocotrienols, a vitamin E subgroup, exert potent anticancer effects, but easily degrade due to oxidation. Eight vitamin E reference compounds, α-, β-, γ-, or δ-tocopherols or -tocotrienols, were thermally oxidized in n-hexane. The corresponding predominantly dimeric oxidation products were separated from the parent compounds by diol-modified normal-phase HPLC-UV and characterized by mass spectroscopy. The composition of test compounds, that is, α-tocotrienol, γ-tocotrienol, or palm tocotrienol-rich fraction (TRF), before and after thermal oxidation was determined by HPLC-DAD, and MCF-7 cells were treated with both nonoxidized and oxidized test compounds for 72 h. Whereas all nonoxidized test compounds (0-100 μM) led to dose-dependent decreases in cell viability, equimolar oxidized α-tocotrienol had a weaker effect, and oxidized TRF had no such effect. However, the IC50 value of oxidized γ-tocotrienol was lower (85 μM) than that of nonoxidized γ-tocotrienol (134 μM), thereby suggesting that γ-tocotrienol oxidation products are able to reduce tumor cell viability in vitro.
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Affiliation(s)
- Astrid M Drotleff
- Department of Analytical Chemistry and ‡Department of Food Toxicology, Center for Food Sciences, Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover Foundation , Bischofsholer Damm 15, D-30173 Hannover, Germany
| | - Anne Büsing
- Department of Analytical Chemistry and ‡Department of Food Toxicology, Center for Food Sciences, Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover Foundation , Bischofsholer Damm 15, D-30173 Hannover, Germany
| | - Ina Willenberg
- Department of Analytical Chemistry and ‡Department of Food Toxicology, Center for Food Sciences, Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover Foundation , Bischofsholer Damm 15, D-30173 Hannover, Germany
| | - Michael T Empl
- Department of Analytical Chemistry and ‡Department of Food Toxicology, Center for Food Sciences, Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover Foundation , Bischofsholer Damm 15, D-30173 Hannover, Germany
| | - Pablo Steinberg
- Department of Analytical Chemistry and ‡Department of Food Toxicology, Center for Food Sciences, Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover Foundation , Bischofsholer Damm 15, D-30173 Hannover, Germany
| | - Waldemar Ternes
- Department of Analytical Chemistry and ‡Department of Food Toxicology, Center for Food Sciences, Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover Foundation , Bischofsholer Damm 15, D-30173 Hannover, Germany
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20
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Ordoñez R, Fernández A, Prieto-Domínguez N, Martínez L, García-Ruiz C, Fernández-Checa JC, Mauriz JL, González-Gallego J. Ceramide metabolism regulates autophagy and apoptotic cell death induced by melatonin in liver cancer cells. J Pineal Res 2015; 59:178-89. [PMID: 25975536 PMCID: PMC4523438 DOI: 10.1111/jpi.12249] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 05/08/2015] [Indexed: 12/22/2022]
Abstract
Autophagy is a process that maintains homeostasis during stress, although it also contributes to cell death under specific contexts. Ceramides have emerged as important effectors in the regulation of autophagy, mediating the crosstalk with apoptosis. Melatonin induces apoptosis of cancer cells; however, its role in autophagy and ceramide metabolism has yet to be clearly elucidated. This study was aimed to evaluate the effect of melatonin administration on autophagy and ceramide metabolism and its possible link with melatonin-induced apoptotic cell death in hepatocarcinoma (HCC) cells. Melatonin (2 mm) transiently induced autophagy in HepG2 cells through JNK phosphorylation, characterized by increased Beclin-1 expression, p62 degradation, and LC3II and LAMP-2 colocalization, which translated in decreased cell viability. Moreover, ATG5 silencing sensitized HepG2 cells to melatonin-induced apoptosis, suggesting a dual role of autophagy in cell death. Melatonin enhanced ceramide levels through both de novo synthesis and acid sphingomyelinase (ASMase) stimulation. Serine palmitoyltransferase (SPT) inhibition with myriocin prevented melatonin-induced autophagy and ASMase inhibition with imipramine-impaired autophagy flux. However, ASMase inhibition partially protected HepG2 cells against melatonin, while SPT inhibition significantly enhanced cell death. Findings suggest a crosstalk between SPT-mediated ceramide generation and autophagy in protecting against melatonin, while specific ASMase-induced ceramide production participates in melatonin-mediated cell death. Thus, dual blocking of SPT and autophagy emerges as a potential strategy to potentiate the apoptotic effects of melatonin in liver cancer cells.
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Affiliation(s)
- Raquel Ordoñez
- Institute of Biomedicine (IBIOMED), University of León, León, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Spain
| | - Ana Fernández
- Institute of Biomedicine (IBIOMED), University of León, León, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Spain
| | - Néstor Prieto-Domínguez
- Institute of Biomedicine (IBIOMED), University of León, León, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Spain
| | - Laura Martínez
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB), Consejo Superior Investigaciones Cientificas (CSIC) and Liver Unit-Hospital Clinic, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Spain
| | - Carmen García-Ruiz
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB), Consejo Superior Investigaciones Cientificas (CSIC) and Liver Unit-Hospital Clinic, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Spain
- University of Southern California Research Center for Alcohol Liver and Pancreatic Diseases and Cirrhosis, Keck School of Medicine, USC, Los Angeles, CA, USA
| | - José C. Fernández-Checa
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB), Consejo Superior Investigaciones Cientificas (CSIC) and Liver Unit-Hospital Clinic, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Spain
- University of Southern California Research Center for Alcohol Liver and Pancreatic Diseases and Cirrhosis, Keck School of Medicine, USC, Los Angeles, CA, USA
| | - José L. Mauriz
- Institute of Biomedicine (IBIOMED), University of León, León, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Spain
| | - Javier González-Gallego
- Institute of Biomedicine (IBIOMED), University of León, León, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Spain
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Casasampere M, Ordoñez YF, Pou A, Casas J. Inhibitors of dihydroceramide desaturase 1: Therapeutic agents and pharmacological tools to decipher the role of dihydroceramides in cell biology. Chem Phys Lipids 2015; 197:33-44. [PMID: 26248324 DOI: 10.1016/j.chemphyslip.2015.07.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 07/29/2015] [Accepted: 07/31/2015] [Indexed: 02/07/2023]
Abstract
Dihydroceramide desaturase (Des1) is the last enzyme in the de novo synthesis of ceramides (Cer). It catalyzes the insertion of a double bond into dihydroceramides (dhCer) to convert them to Cer, both of which are further metabolized to more complex (dihydro) sphingolipids. For many years dhCer have received poor attention, mainly due to their supposed lack of biological activity. It was not until about ten years ago that the concept that dhCer might have regulatory roles in biology emerged for the first time. Since then, multiple publications have established that dhCer are implicated in a wide spectrum of biological processes. Physiological and pathophysiological functions of dhCer have been recently reviewed. In this review we will focus on the biochemical features of Des1 and on its inhibition by different compounds with presumably different modes of action.
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Affiliation(s)
- Mireia Casasampere
- Research Unit on BioActive Molecules, Department of Biomedicinal Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, E-08034 Barcelona, Spain
| | - Yadira F Ordoñez
- Research Unit on BioActive Molecules, Department of Biomedicinal Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, E-08034 Barcelona, Spain
| | - Ana Pou
- Research Unit on BioActive Molecules, Department of Biomedicinal Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, E-08034 Barcelona, Spain
| | - Josefina Casas
- Research Unit on BioActive Molecules, Department of Biomedicinal Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, E-08034 Barcelona, Spain.
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22
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Wang Y, Park NY, Jang Y, Ma A, Jiang Q. Vitamin E γ-Tocotrienol Inhibits Cytokine-Stimulated NF-κB Activation by Induction of Anti-Inflammatory A20 via Stress Adaptive Response Due to Modulation of Sphingolipids. THE JOURNAL OF IMMUNOLOGY 2015; 195:126-33. [PMID: 26002975 DOI: 10.4049/jimmunol.1403149] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 04/27/2015] [Indexed: 12/16/2022]
Abstract
NF-κB plays a central role in pathogenesis of inflammation and cancer. Many phytochemicals, including γ-tocotrienol (γTE), a natural form of vitamin E, have been shown to inhibit NF-κB activation, but the underlying mechanism has not been identified. In this study, we show that γTE inhibited cytokine-triggered activation of NF-κB and its upstream regulator TGF-β-activated kinase-1 in murine RAW 264.7 macrophages and primary bone marrow-derived macrophages. In these cells, γTE induced upregulation of A20, an inhibitor of NF-κB. Knockout of A20 partially diminished γTE's anti-NF-κB effect, but γTE increased another NF-κB inhibitor, Cezanne, in A20(-/-) cells. In search of the reason for A20 upregulation, we found that γTE treatment increased phosphorylation of translation initiation factor 2, IκBα, and JNK, indicating induction of endoplasmic reticulum stress. Liquid chromatography-tandem mass spectrometry analyses revealed that γTE modulated sphingolipids, including enhancement of intracellular dihydroceramides, sphingoid bases in de novo synthesis of the sphingolipid pathway. Chemical inhibition of de novo sphingolipid synthesis partially reversed γTE's induction of A20 and the anti-NF-κB effect. The importance of dihydroceramide increase is further supported by the observation that C8-dihydroceramide mimicked γTE in upregulating A20, enhancing endoplasmic reticulum stress, and attenuating TNF-triggered NF-κB activation. Our study identifies a novel anti-NF-κB mechanism where A20 is induced by stress-induced adaptive response as a result of modulation of sphingolipids, and it demonstrates an immunomodulatory role of dihydrocermides.
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Affiliation(s)
- Yun Wang
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907; and
| | - Na-Young Park
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907; and
| | - Yumi Jang
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907; and
| | - Averil Ma
- Department of Medicine, University of California at San Francisco, San Francisco, CA 94143
| | - Qing Jiang
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907; and
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Alqahtani S, Alayoubi A, Nazzal S, Sylvester PW, Kaddoumi A. Enhanced solubility and oral bioavailability of γ-tocotrienol using a self-emulsifying drug delivery system (SEDDS). Lipids 2014; 49:819-29. [PMID: 24934591 DOI: 10.1007/s11745-014-3923-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 05/31/2014] [Indexed: 12/30/2022]
Abstract
The aim of this study was to evaluate the in vitro and in vivo performance of γ-tocotrienol (γ-T3) incorporated in a self-emulsifying drug delivery system (SEDDS) and to compare its enhanced performance to a commercially available product, namely Tocovid Suprabio™ (hereafter Tocovid), containing tocotrienols. The solubilization of γ-T3 was tested in a dynamic in vitro lipolysis model followed by in vitro cellular uptake study for the lipolysis products. In addition, in vitro uptake studies using Caco2 cells were conducted at different concentrations of γ-T3 prepared as SEDDS, Tocovid, or mixed micelles. γ-T3 incorporated in SEDDS or Tocovid was orally administered to rats at different doses and absolute oral bioavailability from both formulations were determined. The dynamic in vitro lipolysis experiment showed about two fold increase in the solubilization of γ-T3 prepared as SEDDS compared to Tocovid, which correlated with higher cellular uptake in the subsequent uptake studies. In vitro cellular uptake and in vivo oral bioavailability studies have shown a twofold increase in the cellular uptake and oral bioavailability of γ-T3 incorporated in SEDDS compared to Tocovid as a result of improvement in its solubility and passive uptake as confirmed by in vitro studies. In conclusion, incorporation of γ-T3 in SEDDS formulation enhanced γ-T3 solubilization and passive permeability, thus its cellular uptake and oral bioavailability when compared to Tocovid.
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Affiliation(s)
- Saeed Alqahtani
- Department of Basic Pharmaceutical Sciences, College of Pharmacy, University of Louisiana at Monroe, 1800 Bienville Dr., Monroe, LA, 71201, USA
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Autophagy inhibitor 3-methyladenine potentiates apoptosis induced by dietary tocotrienols in breast cancer cells. Eur J Nutr 2014; 54:265-72. [PMID: 24830781 DOI: 10.1007/s00394-014-0707-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 04/24/2014] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Tocomin® represents commercially available mixture of naturally occurring tocotrienols (T3s) and tocopherols extracted from palm oil/palm fruits that possess powerful antioxidant, anticancer, neuro/cardioprotective and cholesterol-lowering properties. Cellular autophagy represents a defense mechanism against oxidative stress and several anticancer compounds. Recently, we reported that T3s induce apoptosis and endoplasmic reticulum stress in breast cancer cells. METHODOLOGY We studied the effects of Tocomin® on MCF-7 and MDA-MB 231 breast cancer cells and non-tumor MCF-10A cells. RESULTS Tocomin® inhibited cell proliferation and induced apoptosis in both MCF-7 and MDA-MB 231 breast cancer cell lines without affecting the viability of MCF-10A cells. We also showed that Tocomin® negatively modulates phosphoinositide 3-kinase and mTOR pathways and induces cytoprotective autophagic response in triple negative MDA-MB 231 cells. Lastly, we demonstrate that autophagy inhibitor 3-methyladenine (3-MA) potentiated the apoptosis induced by Tocomin® in MDA-MB 231 cells. CONCLUSION Together, our data indicate anticancer effects of Tocomin® in breast cancer cells, which is potentiated by the autophagy inhibitor 3-MA.
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Sylvester PW, Akl MR, Malaviya A, Parajuli P, Ananthula S, Tiwari RV, Ayoub NM. Potential role of tocotrienols in the treatment and prevention of breast cancer. Biofactors 2014; 40:49-58. [PMID: 23804535 DOI: 10.1002/biof.1116] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 04/29/2013] [Accepted: 05/07/2013] [Indexed: 12/22/2022]
Abstract
Vitamin E is a generic term that refers to a family of compounds that is further divided into two subgroups called tocopherols and tocotrienols. Although all natural forms of vitamin E display potent antioxidant activity, tocotrienols are significantly more potent than tocopherols in inhibiting tumor cell growth and viability, and anticancer activity of tocotrienols is mediated independently of their antioxidant activity. In addition, the anticancer effects of tocotrienols are observed using treatment doses that have little or no effect on normal cell function or viability. This review will summarize experimental studies that have identified the intracellular mechanism mediating the anticancer effects of tocotrienols. Evidence is also provided showing that combined treatment of tocotrienol with other cancer chemotherapies can result in a synergistic inhibition in cancer cell growth and viability. Taken together, these findings strongly indicate that tocotrienols may provide significant health benefits in the prevention and/or treatment of cancer when used either alone as monotherapy or in combination with other anticancer agents.
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Affiliation(s)
- Paul W Sylvester
- Department of Basic Pharmaceutical Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA, USA
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