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Lee ZY, Lee WH, Lim JS, Ali AAA, Loo JSE, Wibowo A, Mohammat MF, Foo JB. Golgi apparatus targeted therapy in cancer: Are we there yet? Life Sci 2024; 352:122868. [PMID: 38936604 DOI: 10.1016/j.lfs.2024.122868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 06/14/2024] [Accepted: 06/20/2024] [Indexed: 06/29/2024]
Abstract
Membrane trafficking within the Golgi apparatus plays a pivotal role in the intracellular transportation of lipids and proteins. Dysregulation of this process can give rise to various pathological manifestations, including cancer. Exploiting Golgi defects, cancer cells capitalise on aberrant membrane trafficking to facilitate signal transduction, proliferation, invasion, immune modulation, angiogenesis, and metastasis. Despite the identification of several molecular signalling pathways associated with Golgi abnormalities, there remains a lack of approved drugs specifically targeting cancer cells through the manipulation of the Golgi apparatus. In the initial section of this comprehensive review, the focus is directed towards delineating the abnormal Golgi genes and proteins implicated in carcinogenesis. Subsequently, a thorough examination is conducted on the impact of these variations on Golgi function, encompassing aspects such as vesicular trafficking, glycosylation, autophagy, oxidative mechanisms, and pH alterations. Lastly, the review provides a current update on promising Golgi apparatus-targeted inhibitors undergoing preclinical and/or clinical trials, offering insights into their potential as therapeutic interventions. Significantly more effort is required to advance these potential inhibitors to benefit patients in clinical settings.
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Affiliation(s)
- Zheng Yang Lee
- School of Pharmacy, Faculty of Health and Medical Sciences, Taylor's University, 47500 Subang Jaya, Selangor, Malaysia
| | - Wen Hwei Lee
- School of Pharmacy, Faculty of Health and Medical Sciences, Taylor's University, 47500 Subang Jaya, Selangor, Malaysia
| | - Jing Sheng Lim
- School of Pharmacy, Faculty of Health and Medical Sciences, Taylor's University, 47500 Subang Jaya, Selangor, Malaysia
| | - Afiqah Ali Ajmel Ali
- School of Pharmacy, Faculty of Health and Medical Sciences, Taylor's University, 47500 Subang Jaya, Selangor, Malaysia
| | - Jason Siau Ee Loo
- School of Pharmacy, Faculty of Health and Medical Sciences, Taylor's University, 47500 Subang Jaya, Selangor, Malaysia; Digital Health and Medical Advancements Impact Lab, Taylor's University, Subang Jaya 47500, Selangor, Malaysia
| | - Agustono Wibowo
- Faculty of Applied Science, Universiti Teknologi MARA (UiTM) Pahang, Jengka Campus, 26400 Bandar Tun Abdul Razak Jengka, Pahang, Malaysia
| | - Mohd Fazli Mohammat
- Organic Synthesis Laboratory, Institute of Science, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor, Malaysia
| | - Jhi Biau Foo
- School of Pharmacy, Faculty of Health and Medical Sciences, Taylor's University, 47500 Subang Jaya, Selangor, Malaysia; Digital Health and Medical Advancements Impact Lab, Taylor's University, Subang Jaya 47500, Selangor, Malaysia
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Lee ZY, Loo JSE, Wibowo A, Mohammat MF, Foo JB. Targeting cancer via Golgi α-mannosidase II inhibition: How far have we come in developing effective inhibitors? Carbohydr Res 2021; 508:108395. [PMID: 34280804 DOI: 10.1016/j.carres.2021.108395] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/01/2021] [Accepted: 07/01/2021] [Indexed: 11/22/2022]
Abstract
Dysregulation of glycosylation pathways has been well documented in several types of cancer, where it often participates in cancer development and progression, especially cancer metastasis. Hence, inhibition of glycosidases such as mannosidases can disrupt the biosynthesis of glycans on cell surface glycoproteins and modify their role in carcinogenesis and metastasis. Several reviews have delineated the role of N-glycosylation in cancer, but the data regarding effective inhibitors remains sparse. Golgi α-mannosidase has been an attractive therapeutic target for preventing the formation of ß1,6-branched complex type N-glycans. However, due to its high structural similarity to the broadly specific lysosomal α-mannosidase, undesired co-inhibition occurs and this leads to serious side effects that complicates its potential role as a therapeutic agent. Even though extensive efforts have been geared towards the discovery of effective inhibitors, no breakthrough has been achieved thus far which could allow for their use in clinical settings. Improving the specificity of current inhibitors towards Golgi α-mannosidase is requisite in progressing this class of compounds in cancer chemotherapy. In this review, we highlight a few potent and selective inhibitors discovered up to the present to guide researchers for rational design of further effective inhibitors to overcome the issue of specificity.
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Affiliation(s)
- Zheng Yang Lee
- School of Pharmacy, Faculty of Health & Medical Sciences, Taylor's University, 1, Jalan Taylors, 47500, Subang Jaya, Selangor, Malaysia
| | - Jason Siau Ee Loo
- School of Pharmacy, Faculty of Health & Medical Sciences, Taylor's University, 1, Jalan Taylors, 47500, Subang Jaya, Selangor, Malaysia; Centre for Drug Discovery and Molecular Pharmacology, Faculty of Health & Medical Sciences, Taylor's University, 1, Jalan Taylors, 47500, Subang Jaya, Selangor, Malaysia
| | - Agustono Wibowo
- Faculty of Applied Science, Universiti Teknologi MARA (UiTM) Pahang, Jengka Campus, 26400, Bandar Tun Abdul Razak Jengka, Pahang, Malaysia
| | - Mohd Fazli Mohammat
- Organic Synthesis Laboratory, Institute of Science, Universiti Teknologi MARA (UiTM), 40450, Shah Alam, Selangor, Malaysia
| | - Jhi Biau Foo
- School of Pharmacy, Faculty of Health & Medical Sciences, Taylor's University, 1, Jalan Taylors, 47500, Subang Jaya, Selangor, Malaysia; Centre for Drug Discovery and Molecular Pharmacology, Faculty of Health & Medical Sciences, Taylor's University, 1, Jalan Taylors, 47500, Subang Jaya, Selangor, Malaysia.
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Chenchen W, Wenlong W, Xiaoxue L, Feng M, Dandan C, Xiaowen Y, Shanshan W, Pengshuai G, Hao L, Baoyu Z. Pathogenesis and preventive treatment for animal disease due to locoweed poisoning. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2014; 37:336-347. [PMID: 24388907 DOI: 10.1016/j.etap.2013.11.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 11/05/2013] [Accepted: 11/10/2013] [Indexed: 06/03/2023]
Abstract
Locoweeds are perennial herbaceous plants included in Astragalus spp. and Oxytropis spp. that contain the toxic indolizidine alkaloid swainsonine. The livestock that consume locoweed feeding can suffer from a type of toxicity called "locoism." There are aliphatic nitro compounds, selenium, selenium compounds and alkaloids in locoweed. The toxic component in locoweeds has been identified as swainsonine, an indolizidine alkaloid. Swainsonine inhibits lysosomal α-mannosidase and mannosidase II, resulting in altered oligosaccharide degradation and incomplete glycoprotein processing. As a result, livestock that consume locoweeds exhibit several symptoms, including dispirited behavior, staggering gait, chromatopsia, trembling, ataxia, and cellular vacuolar degeneration of most tissues by pathological observation. Locoism results in significant annual economic losses. Recently, locoweed populations have increased domestically in China and abroad, resulting in an increase in the incidence of poisoning. Therefore, in this paper, we review the current research on locoweed, including on species variation, pathogenesis, damage and poisoning prevention measures.
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Affiliation(s)
- Wu Chenchen
- College of Animal Veterinary Medicine, Northwest A & F University, Yangling 712100, People's Republic of China
| | - Wang Wenlong
- College of Animal Veterinary Medicine, Northwest A & F University, Yangling 712100, People's Republic of China
| | - Liu Xiaoxue
- College of Animal Veterinary Medicine, Northwest A & F University, Yangling 712100, People's Republic of China
| | - Ma Feng
- College of Animal Veterinary Medicine, Northwest A & F University, Yangling 712100, People's Republic of China
| | - Cao Dandan
- College of Animal Veterinary Medicine, Northwest A & F University, Yangling 712100, People's Republic of China
| | - Yang Xiaowen
- College of Animal Veterinary Medicine, Northwest A & F University, Yangling 712100, People's Republic of China
| | - Wang Shanshan
- College of Animal Veterinary Medicine, Northwest A & F University, Yangling 712100, People's Republic of China
| | - Geng Pengshuai
- College of Animal Veterinary Medicine, Northwest A & F University, Yangling 712100, People's Republic of China
| | - Lu Hao
- College of Animal Veterinary Medicine, Northwest A & F University, Yangling 712100, People's Republic of China
| | - Zhao Baoyu
- College of Animal Veterinary Medicine, Northwest A & F University, Yangling 712100, People's Republic of China.
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Li Z, Xu X, Huang Y, Ding L, Wang Z, Yu G, Xu D, Li W, Tong D. Swainsonine activates mitochondria-mediated apoptotic pathway in human lung cancer A549 cells and retards the growth of lung cancer xenografts. Int J Biol Sci 2012; 8:394-405. [PMID: 22393311 PMCID: PMC3291856 DOI: 10.7150/ijbs.3882] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 02/19/2012] [Indexed: 11/13/2022] Open
Abstract
Swainsonine (1, 2, 8-trihyroxyindolizidine, SW), a natural alkaloid, has been reported to exhibit anti-cancer activity on several mouse models of human cancer and human cancers in vivo. However, the mechanisms of SW-mediated tumor regression are not clear. In this study, we investigated the effects of SW on several human lung cancer cell lines in vitro. The results showed that SW significantly inhibited these cells growth through induction of apoptosis in different extent in vitro. Further studies showed that SW treatment up-regulated Bax, down-regulated Bcl-2 expression, promoted Bax translocation to mitochondria, activated mitochondria-mediated apoptotic pathway, which in turn caused the release of cytochrome c, the activation of caspase-9 and caspase-3, and the cleavage of poly (ADP-ribose) polymerase (PARP), resulting in A549 cell apoptosis. However, the expression of Fas, Fas ligand (FasL) or caspase-8 activity did not appear significant changes in the process of SW-induced apoptosis. Moreover, SW treatment inhibited Bcl-2 expression, promoted Bax translocation, cytochrome c release and caspase-3 activity in xenograft tumor cells, resulting in a significant decrease of tumor volume and tumor weight in the SW-treated xenograft mice groups in comparison to the control group. Taken together, this study demonstrated for the first time that SW inhibited A549 cancer cells growth through a mitochondria-mediated, caspase-dependent apoptotic pathway in vitro and in vivo.
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Affiliation(s)
- Zhaocai Li
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, PR China
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Hueza IM, Górniak SL. The immunomodulatory effects of Ipomoea carnea in rats vary depending on life stage. Hum Exp Toxicol 2011; 30:1690-700. [DOI: 10.1177/0960327110399477] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ipomoea carnea Jacq. ssp. fistulosa (Mart. Ex Choisy; Convolvulaceae; I. carnea) possesses a toxic component: an indolizidine alkaloid swainsonine (SW) that has immunomodulatory effects due to its inhibition of glycoprotein metabolism. It is also known that SW is excreted into both the amniotic fluid and milk of female rats exposed to I. carnea. Thus, the aim of this study was to determine whether SW exposure, either in utero or from the milk of dams treated with I. carnea, modulates offspring immune function into adulthood. In addition, adult (70 days old) and juvenile rats (21 days old) were exposed to I. carnea in order to evaluate several other immune parameters: lymphoid organs relative weight and cellularity, humoral and cellular immune responses. Offspring exposed to I. carnea during lactation developed rheumatoid arthritis (RA) in adulthood after an immunogenic challenge. In addition, both adult and juvenile rats exposed to I. carnea showed discrepancies in several immune parameters, but did not exhibit any decrease in humoral immune response, which was enhanced at both ages. These findings indicate that SW modulates immune function in adult rats exposed to SW during lactation and in juvenile and adult rats exposed to SW as juveniles and adults, respectively.
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Affiliation(s)
- Isis M Hueza
- Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo (UNIFESP), Diadema, S.P., Brazil
| | - Silvana L Górniak
- Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo (USP), São Paulo, S.P., Brazil
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Shah AS, Juvekar AR. In vitro and in vivo immunostimulatory activity of Woodfordia fruticosa flowers on non-specific immunity. PHARMACEUTICAL BIOLOGY 2010; 48:1066-1072. [PMID: 20731559 DOI: 10.3109/13880200903490497] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
CONTEXT Woodfordia fruticosa Kurz. (Lythraceae), a non-rasayana immunomodulatory Indian medicinal plant, used traditionally as an anthelmintic, in dysentery, leprosy, blood diseases, leucorrhea, and menorrhagia. OBJECTIVE To investigate the effect of ethanol extract of W. fruticosa flowers on non-specific immune responses in mice. MATERIALS AND METHODS In vitro immunomodulatory activity of the extract was examined on murine peritoneal macrophage phagocytosis (nitroblue tetrazolium (NBT) dye reduction, lysosomal enzyme activity, nitric oxide and myeloperoxidase) and on proliferation of bone marrow cells by sulforhodamine B (SRB) assay, while the in vivo potential on macrophages and bone marrow cells was evaluated by using carbon clearance test and cyclophosphamide-induced myelosuppression, respectively. RESULTS Significant increase in the release of myeloperoxidase, nitric oxide lysosomal enzyme and superoxide from macrophages along with significant increase in phagocytic index in carbon clearance test indicate stimulatory activity of the extract on macrophages. The extract also demonstrated 60% increase in bone marrow cell proliferation and offer protection towards cyclophosphamide-induced myelosuppression which represents the stimulation of bone marrow activity. DISCUSSION Significant increase in mediators released from macrophages and phagocytic index in carbon clearance test suggests the release of cytokines from macrophages and stimulation of reticulo-endothelial system. Proliferation of bone marrow cells indicates the plausible release of colony stimulating factors, which further stimulates the immune system through generation of immune cells. CONCLUSION The result described here indicates the immunostimulatory activity of ethanol extract of W. fruticosa flowers by stimulating non-specific immune responses, macrophages and bone marrow cells.
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MESH Headings
- Adjuvants, Immunologic/pharmacology
- Adjuvants, Immunologic/therapeutic use
- Adjuvants, Immunologic/toxicity
- Animals
- Bone Marrow Cells/drug effects
- Cell Proliferation/drug effects
- Cells, Cultured
- Female
- Flowers/chemistry
- Free Radicals/metabolism
- Immunity, Innate/drug effects
- Leukopenia/blood
- Leukopenia/chemically induced
- Leukopenia/drug therapy
- Lysosomes/drug effects
- Lysosomes/enzymology
- Lysosomes/metabolism
- Macrophages, Peritoneal/drug effects
- Macrophages, Peritoneal/enzymology
- Macrophages, Peritoneal/metabolism
- Male
- Medicine, Ayurvedic
- Mice
- Myeloablative Agonists/antagonists & inhibitors
- Myeloablative Agonists/toxicity
- Peroxidase/metabolism
- Phagocytosis/drug effects
- Phytotherapy
- Plant Extracts/pharmacology
- Plant Extracts/therapeutic use
- Plant Extracts/toxicity
- Toxicity Tests, Acute
- Woodfordia/chemistry
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Affiliation(s)
- Abhishek S Shah
- Department of Pharmaceutical Sciences and Technology, Mumbai University Institute of Chemical Technology, Nathalal Parikh Marg, Matunga, Mumbai, India
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Intervention of alpha-lipoic acid ameliorates methotrexate-induced oxidative stress and genotoxicity: A study in rat intestine. Chem Biol Interact 2010; 183:85-97. [PMID: 19900424 DOI: 10.1016/j.cbi.2009.10.020] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 10/28/2009] [Accepted: 10/29/2009] [Indexed: 12/18/2022]
Abstract
Methotrexate (MTX) is an anti-metabolite, widely used in the cancer chemotherapy and rheumatoid arthritis. However, its long-term clinical use is restricted on account of its severe intestinal toxicity. The present study was aimed to investigate the intestinal toxicity of MTX and the possible protective effect of alpha-lipoic acid (LA) on Sprague-Dawley rats. MTX-induced intestinal toxicity was evaluated at the dose of 2.5mg/kg for short-term (5 days treatment) and 1mg/kg for long-term (5 days in a week for four consecutive weeks treatment) study. The possible protective effect of LA was evaluated in both short- as well as long-term study in a dose-dependent manner. MTX treatment induced diarrhoea and mortality in rats, indicating its severe toxicity in the target organ of investigation, i.e., intestine. Further, the intestinal toxicity of MTX was assessed by evaluating different parameters of oxidative stress, DNA damage, cytotoxicity as well as histological changes. Immunostaining for p53 revealed higher genotoxic assault in the intestinal cells due to MTX treatment. Pretreatment of rats with LA led to significant decrease in the oxidative stress, DNA damage, cellular damage, inflammatory changes and apoptosis as determined by malondialdehyde level, glutathione level, comet assay parameters, histological evaluation, immunostaining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. In the present investigation, we report that LA pretreatment ameliorates MTX-induced intestinal toxicity in rat as evident from the protection against oxidative stress, decrease in DNA damage and protection of cellular morphology as well as improvement in the stool consistency and animal survival rate.
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Hamaguchi J, Nakagawa H, Takahashi M, Kudo T, Kamiyama N, Sun B, Oshima T, Sato Y, Deguchi K, Todo S, Nishimura SI. Swainsonine reduces 5-fluorouracil tolerance in the multistage resistance of colorectal cancer cell lines. Mol Cancer 2007; 6:58. [PMID: 17883871 PMCID: PMC2071919 DOI: 10.1186/1476-4598-6-58] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2007] [Accepted: 09/21/2007] [Indexed: 01/11/2023] Open
Abstract
Background Drug resistance is a major problem in cancer chemotherapy. Acquisition of chemo-resistance not only reduces the effectiveness of drugs, but also promotes side effects and markedly reduces the patient's quality of life. However, a number of resistance mechanisms have been reported and are thought to be the reason for the difficulties in solving drug-resistance problems. Result To investigate the mechanisms of drug resistance, a set of cell lines with different levels of sensitivity and possessing different mechanisms of resistance to 5-fluorouracil (5-FU) was established from a colorectal cancer cell line. The expression of thymidylate synthase, orotic acid phosphoribosyltransferase and dihydropyrimidine dehydrogenase, which are well known to be related to drug resistance, differed among these cell lines, indicating that these cell lines acquired different resistance mechanisms. However, swainsonine, an inhibitor of N-glycan biosynthesis, reduced 5-FU-tolerance in all resistant cells, whereas the sensitivity of the parental cells was unchanged. Further analysis of the N-glycan profiles of all cell lines showed partial inhibition of biosynthesis and no cytotoxicity at the swainsonine dosage tested. Conclusion These observations suggest that N-linked oligosaccharides affect 5-FU resistance more widely than do drug-resistance related enzymes in colorectal cancer cells, and that the N-glycan could be a universal target for chemotherapy. Further, swainsonine may enhance the performance of chemotherapy by reducing tolerance.
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Affiliation(s)
- Jun Hamaguchi
- Department of General Surgery, Graduate School of Medicine, Hokkaido University, Sapporo 060-8638, Japan
| | - Hiroaki Nakagawa
- Graduate School of Advanced Life Science, Hokkaido University, Sapporo 001-0021, 001-0021, Japan
| | - Masato Takahashi
- Department of General Surgery, Graduate School of Medicine, Hokkaido University, Sapporo 060-8638, Japan
| | - Takeaki Kudo
- Department of General Surgery, Graduate School of Medicine, Hokkaido University, Sapporo 060-8638, Japan
| | - Naoya Kamiyama
- Department of Sensory Physiology, Asahikawa Medical College, Asahikawa 078-8510, Japan
| | - Bailong Sun
- Department of General Surgery, Graduate School of Medicine, Hokkaido University, Sapporo 060-8638, Japan
| | - Takahiro Oshima
- Department of General Surgery, Graduate School of Medicine, Hokkaido University, Sapporo 060-8638, Japan
| | - Yuji Sato
- Department of General Surgery, Graduate School of Medicine, Hokkaido University, Sapporo 060-8638, Japan
| | - Kisaburo Deguchi
- Graduate School of Advanced Life Science, Hokkaido University, Sapporo 001-0021, 001-0021, Japan
| | - Satoru Todo
- Department of General Surgery, Graduate School of Medicine, Hokkaido University, Sapporo 060-8638, Japan
| | - Shin-Ichiro Nishimura
- Graduate School of Advanced Life Science, Hokkaido University, Sapporo 001-0021, 001-0021, Japan
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James LF, Panter KE, Gaffield W, Molyneux RJ. Biomedical applications of poisonous plant research. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2004; 52:3211-30. [PMID: 15161174 DOI: 10.1021/jf0308206] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Research designed to isolate and identify the bioactive compounds responsible for the toxicity of plants to livestock that graze them has been extremely successful. The knowledge gained has been used to design management techniques to prevent economic losses, predict potential outbreaks of poisoning, and treat affected animals. The availability of these compounds in pure form has now provided scientists with tools to develop animal models for human diseases, study modes of action at the molecular level, and apply such knowledge to the development of potential drug candidates for the treatment of a number of genetic and infectious conditions. These advances are illustrated by specific examples of biomedical applications of the toxins of Veratrum californicum (western false hellebore), Lupinus species (lupines), and Astragalus and Oxytropis species (locoweeds).
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Affiliation(s)
- Lynn F James
- Poisonous Plant Research Laboratory, Agricultural Research Service, US Department of Agriculture, 1150 East 1400 North, Logan, Utah 84341, USA.
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Oredipe OA, Furbert-Harris PM, Laniyan I, Griffin WM, Sridhar R. Limits of stimulation of proliferation and differentiation of bone marrow cells of mice treated with swainsonine. Int Immunopharmacol 2003; 3:1537-47. [PMID: 12946451 DOI: 10.1016/s1567-5769(03)00186-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The limits of stimulation of the immunomodulatory alkaloid swainsonine (8alphabeta-indolizidine-1alpha,2alpha,8beta-triol) were studied in inbred C57BL/6 mice for potential support of intense high dose cancer chemotherapy and/or radiation because of its attractive pharmacologic profile on the hematopoietic system. Specifically, the effects of swainsonine on bone marrow cellularity and on in vitro progenitor cell proliferation to total colony forming units (CFU) and differentiation to different lineages were studied as a function of number of days post drug administration. The lineages evaluated were colony forming units-granulocyte-macrophage (CFU-GM), erythroid-burst forming units (BFU-e) and CFU-granulocyte-erythrocyte-monocyte-megakaryocyte (CFU-GEMM or CFU-Mix). Groups of mice were treated with swainsonine or plain vehicle, phosphate buffered saline for 10 consecutive days. The effects of these agents on the hematopoietic system were studied up to 60 days following their discontinuation. The magnitude of the effects of swainsonine on bone marrow system gradually declined with increasing duration of days following its discontinuation. Nevertheless, its residual stimulatory effects on bone marrow cellularity, total CFU, CFU-GM, BFU-e and CFU-Mix continued to be significant (P<0.0001) up to 45, 50, 50, 55 and 50 days, respectively, compared to those of diluent buffer or untreated controls. Since cancer chemotherapeutic agents or radiation are normally given in schedules and/or cycles, these results strongly suggest that swainsonine effects are sustained long enough to potentially support and facilitate hematopoietic recovery during anti-cancer cytotoxic treatment.
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Affiliation(s)
- Oladipo A Oredipe
- Department of Pharmacology, Howard University College of Medicine, Washington, DC 20060, USA.
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Gardner DR, Lee ST, Molyneux RJ, Edgar JA. Preparative isolation of swainsonine from locoweed: extraction and purification procedures. PHYTOCHEMICAL ANALYSIS : PCA 2003; 14:259-266. [PMID: 12892424 DOI: 10.1002/pca.713] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The trihydroxy indolizidine alkaloid swainsonine, a plant toxin with potent alpha-mannosidase-inhibitory activity and chemotherapeutic potential, was isolated in gram quantities from locoweed (Astragalus lentiginosus). The key isolation and purification step was a continuous liquid/liquid extraction procedure using dichloromethane to extract a basified aqueous methanol solution obtained after isolation of the polar base fraction by ion-exchange. The concentration of swainsonine was increased from ca. 7% in the polar base material to 68% using the liquid/liquid extraction procedure. Pure swainsonine was then obtained by recrystallisation from ammonia-saturated chloroform or by sublimation. Small samples of swainsonine were also purified by formation of the chloroform-soluble methylboronate derivative, from which the alkaloid could be regenerated easily by hydrolysis.
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Affiliation(s)
- Dale R Gardner
- Poisonous Plant Research Laboratory, Agricultural Research Service, USDA,1150 E. 1400 N., Logan, UT 84341, USA.
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Oredipe OA, Furbert-Harris PM, Laniyan I, Green WR, White SL, Olden K, Parish-Gause D, Vaughn T, Griffin WM, Sridhar R. Enhanced proliferation of functionally competent bone marrow cells in different strains of mice treated with swainsonine. Int Immunopharmacol 2003; 3:445-55. [PMID: 12639822 DOI: 10.1016/s1567-5769(03)00042-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The immunomodulatory alkaloid swainsonine (8alphabeta-indolizidine-1alpha,2alpha,8beta-triol) has potential for overcoming the bone marrow suppressive effects of cancer chemotherapy and radiotherapy. An earlier study showed that multiple doses of swainsonine enhanced bone marrow cellularity in four different strains (C57BL/6; C3H-HEN; Balb/C and DBA-2 mice) of inbred mice which were not exposed to any chemotherapeutic agents or radiation. In vitro assessment of total colony formation capacity of bone marrow cells (BM CFUs) showed a 2- to 8-fold increase in swainsonine-treated mice compared to control mice that were given sham injections of physiological saline. In the current study, we have evaluated the functional competence of the bone marrow cells produced in response to swainsonine treatment of normal healthy mice. In particular, colony forming units-granulocyte-macrophage (CFU-GM), erythroid-burst forming units (BFUe) and CFU-Mix (or CFU-granulocyte-erythrocyte-monocyte-megakaryocyte (CFU-GEMM)) levels, were determined using in vitro assays. The time course of the changes in CFU-GM, BFUe and CFU-Mix (CFU-GEMM) were also followed. Our results demonstrate that swainsonine bolsters the CFU capacity of BM cells without loss of function to levels which are several folds higher than in sham-treated control mice. Swainsonine treatment caused an increase in all lineages of marrow cells without loss of function. This effect was reproduced in all four strains of inbred mice in this investigation. Examination of the peripheral blood did not reveal increase in white blood cells or changes in the hematocrit levels. The long-term effects of swainsonine treatment are not known at present. Nonetheless, swainsonine-induced increase in CFU capacity of bone marrow cells and related cells along the different differentiation paths should find clinical application in cancer treatment with chemotherapeutic agents and/or radiation.
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Affiliation(s)
- Oladipo A Oredipe
- Department of Pharmacology, Howard University College of Medicine, Washington, DC 20060, USA.
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Oredipe OA, Furbert-Harris PM, Green WR, White SL, Olden K, Laniyan I, Parish-Gause D, Vaughn T, Griffin WM, Sridhar R. Swainsonine stimulates bone marrow cell proliferation and differentiation in different strains of inbred mice. Pharmacol Res 2003; 47:69-74. [PMID: 12526864 DOI: 10.1016/s1043-6618(02)00254-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The immunomodulatory alkaloid swainsonine (8alphabeta-indolizidine-1alpha,2alpha,8beta-triol) has potential for overcoming the bone marrow suppressive effects of cancer chemotherapeutic drugs and radiation. The effect of swainsonine on bone marrow cellularity was evaluated in four different strains (C57BL/6; C3H-HEN; Balb/C and DBA-2 mice) of inbred mice subjected to multiple doses of the alkaloid. Swainsonine treatment stimulated bone marrow cell proliferation in all strains of mice. Examination of the peripheral blood did not reveal any increase in total leukocyte count. In vitro assessment of total colony-forming unit (CFU) capacity of bone marrow cells showed a two- to eight-fold increase in swainsonine treated mice of different strains compared to their corresponding controls given sham injections of physiological saline. Swainsonine induced increase in CFU capacity of bone marrow cells should find clinical application in cancer treatment with chemotherapeutic agents and radiation.
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Affiliation(s)
- O A Oredipe
- Department of Pharmacology, Howard University College of Medicine, Washington, DC 20060, USA.
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Moremen KW. Golgi alpha-mannosidase II deficiency in vertebrate systems: implications for asparagine-linked oligosaccharide processing in mammals. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1573:225-35. [PMID: 12417404 DOI: 10.1016/s0304-4165(02)00388-4] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The maturation of N-glycans to complex type structures on cellular and secreted proteins is essential for the roles that these structures play in cell adhesion and recognition events in metazoan organisms. Critical steps in the biosynthetic pathway leading from high mannose to complex structures include the trimming of mannose residues by processing mannosidases in the endoplasmic reticulum (ER) and Golgi complex. These exo-mannosidases comprise two separate families of enzymes that are distinguished by enzymatic characteristics and sequence similarity. Members of the Class 2 mannosidase family (glycosylhydrolase family 38) include enzymes involved in trimming reactions in N-glycan maturation in the Golgi complex (Golgi mannosidase II) as well as catabolic enzymes in lysosomes and cytosol. Studies on the biological roles of complex type N-glycans have employed a variety of strategies including the treatment of cells with glycosidase inhibitors, characterization of human patients with enzymatic defects in processing enzymes, and generation of mouse models for the enzyme deficiency by selective gene disruption approaches. Corresponding studies on Golgi mannosidase II have employed swainsonine, an alkaloid natural plant product that causes "locoism", a phenocopy of the lysosomal storage disease, alpha-mannosidosis, as a result of the additional targeting of the broad-specificity lysosomal mannosidase by this compound. The human deficiency in Golgi mannosidase II is characterized by congenital dyserythropoietic anemia with splenomegaly and various additional abnormalities and complications. Mouse models for Golgi mannosidase II deficiency recapitulate many of the pathological features of the human disease and confirm that the unexpectedly mild effects of the enzyme deficiency result from a tissue-specific and glycoprotein substrate-specific alternate pathway for synthesis of complex N-glycans. In addition, the mutant mice develop symptoms of a systemic autoimmune disorder as a consequence of the altered glycosylation. This review will discuss the biochemical features of Golgi mannosidase II and the consequences of its deficiency in mammalian systems as a model for the effects of alterations in vertebrate N-glycan maturation during development.
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Affiliation(s)
- Kelley W Moremen
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA.
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Watson AA, Fleet GW, Asano N, Molyneux RJ, Nash RJ. Polyhydroxylated alkaloids -- natural occurrence and therapeutic applications. PHYTOCHEMISTRY 2001; 56:265-295. [PMID: 11243453 DOI: 10.1016/s0031-9422(00)00451-9] [Citation(s) in RCA: 542] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Over one hundred polyhydroxylated alkaloids have been isolated from plants and micro-organisms. These alkaloids can be potent and highly selective glycosidase inhibitors and are arousing great interest as tools to study cellular recognition and as potential therapeutic agents. However, only three of the natural products so far have been widely studied for therapeutic potential due largely to the limited commercial availability of the other compounds.
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Affiliation(s)
- A A Watson
- Molecular Nature Limited, Aberystwyth, Cardiganshire, UK
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18
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Misago M, Tsukada J, Fukuda MN, Eto S. Suppressive effects of swainsonine and N-butyldeoxynojirimycin on human bone marrow neutrophil maturation. Biochem Biophys Res Commun 2000; 269:219-25. [PMID: 10694503 DOI: 10.1006/bbrc.2000.2269] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of the N-linked oligosaccharide inhibitors swainsonine and N-butyldeoxynojirimycin (NB-DNJ) on granulopoiesis was investigated using human bone marrow cells in in vitro liquid and agar cultures. The addition of the inhibitors into cultures containing granulocyte colony-stimulating factor (G-CSF) suppressed maturation from myelocytes into mature neutrophils. Swainsonine did not induce apoptosis, but NB-DNJ induced considerable apoptosis, especially in the presence of G-CSF. This result indicated that the decrease of mature neutrophils by swainsonine was not because of cell degeneration. In the case of NB-DNJ, it was thought to be because of both maturation suppression and apoptosis. In a colony-forming unit-granuloid (CFU-G) colony assay, the number of colonies was increased in the presence of the inhibitors, but the morphology of colonies was predominantly compact, or immature. The inhibitors also suppressed the expressions of mRNAs of CCAAT/enhancer binding protein epsilon (C/EBPepsilon) and G-CSF receptor as markers of terminal neutrophil maturation. These findings suggested that the incompleteness of N-linked oligosaccharide leads to the suppression of terminal neutrophil maturation.
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Affiliation(s)
- M Misago
- Laboratory of Clinical Hematology, School of Health Sciences, University of Occupational and Environmental Health, Kitakyushu, 807-8555, Japan.
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Wang S, Panter KE, Holyoak GR, Molyneux RJ, Liu G, Evans RC, Bunch TD. Development and viability of bovine preplacentation embryos treated with swainsonine in vitro. Anim Reprod Sci 1999; 56:19-29. [PMID: 10401699 DOI: 10.1016/s0378-4320(99)00029-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This study investigated the effects of swainsonine (a locoweed toxin) on bovine preplacentation embryo development using in vitro procedures. We examined and confirmed the viability and developmental potential of swainsonine-treated embryos by transfer to synchronized recipient heifers. Oocytes (n = 6338) were aspirated from ovaries collected from the abattoir and subjected to in vitro maturation (IVM), in vitro fertilization (IVF) and in vitro culture (IVC). Swainsonine was added to IVM, IVF, IVC media spatially and IVM/IVF/IVC continuously, at 0 ng/ml (TRTI, control), 200 ng/ml (TRT2), 400 ng/ml (TRT3), and 800 ng/ml (TRT4). Embryo development was evaluated with respect to oocyte cleavage rate and the rates of morula and blastocyst formation. There was no difference (P > 0.05) among treatments. The average number of nuclei per blastocyst at Day 7.5 of culture (Day 0 = IVF) was 85.9 +/- 4.3 (n = 47) and 89.3 +/- 4.4 (n = 44) for swainsonine-treated embryos (800 ng/ml) and control embryos, respectively. Pregnancy rate as determined by ultrasonography on day 35 to 40 post embryo transfer was 43.8% and 38.3% for swainsonine-treated (800 ng/ml) and control embryos, respectively. Nine (9.4%) healthy calves were delivered from heifers receiving swainsonine-exposed and nine (9.6%) from control embryos. No difference (P > 0.05) was detected in number of calves developing from TRT and control embryos. We conclude that swainsonine does not have an adverse effect on the development and viability of preplacentation bovine embryos.
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Affiliation(s)
- S Wang
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan 84322-9400, USA.
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Perrone GG, Barrow KD, McFarlane IJ. The selective enzymatic synthesis of lipophilic esters of swainsonine. Bioorg Med Chem 1999; 7:831-5. [PMID: 10400336 DOI: 10.1016/s0968-0896(98)00271-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The potent and specific inhibitor of Golgi alpha-mannosidase II, swainsonine (SW) has been isolated in high yield from Swainsona procumbens and derivatised by regiospecific enzymatic reactions. In this study the regioselectivity of three commercially available enzymes, subtilisin Carlsberg, porcine pancreatic lipase (PPL) and Candida cylindracea lipase was determined for the acylation of swainsonine in predominantly anhydrous organic medium. The use of subtilisin in pyridine facilitated the single step synthesis of 2-O-butyryl-SW in a 23% yield, whilst catalysis by PPL in tetrahydrofuran gave 2-O-butyryl-SW (6%) and 1,2-di-O-butyryl-SW (31%).
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Affiliation(s)
- G G Perrone
- School of Biochemistry & Molecular Genetics, University of New South Wales, Sydney, Australia.
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Klein JL, Roberts JD, George MD, Kurtzberg J, Breton P, Chermann JC, Olden K. Swainsonine protects both murine and human haematopoietic systems from chemotherapeutic toxicity. Br J Cancer 1999; 80:87-95. [PMID: 10389983 PMCID: PMC2363022 DOI: 10.1038/sj.bjc.6690326] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The haematopoietic system is sensitive to cytotoxic damage and is often the site of dose-limiting toxicity. We previously reported that swainsonine, an inhibitor of protein glycosylation, reduced the bone marrow toxicity resulting from a single dose of anticancer drugs in otherwise healthy mice. However, more important questions are (1) can swainsonine protect tumour-bearing mice without interfering with the anti-tumour effects of the drugs, and (2) can swainsonine stimulate haematopoietic activity of human, as well as murine, bone marrow. We demonstrate here that swainsonine protects C57BL/6 mice bearing melanoma-derived tumours from cyclophosphamide-induced toxicity without interfering with the drug's ability to inhibit tumour growth. Similar results were obtained in vivo with 3'-azido-3'-deoxythymidine (AZT), a myelosuppressive agent often used in therapy for acquired immune deficiency syndrome. Swainsonine increased both total bone marrow cellularity and the number of circulating white blood cells in mice treated with doses of AZT that typically lead to severe myelosuppression. Swainsonine also increased the number of erythroid and myeloid colony forming cells (CFCs) in short-term cultures of murine bone marrow, restoring the number of progenitor cells to the control level in the presence of AZT doses that reduced CFCs by 80%. With respect to the sensitivity of human haematopoietic cells to swainsonine, we show that swainsonine protected human myeloid progenitor cells from AZT toxicity in vitro. These results suggest that swainsonine may be useful as an adjuvant in several types of human chemotherapy.
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Affiliation(s)
- J L Klein
- Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
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Roberts JD, Klein JL, Palmantier R, Dhume ST, George MD, Olden K. The role of protein glycosylation inhibitors in the prevention of metastasis and therapy of cancer. CANCER DETECTION AND PREVENTION 1998; 22:455-62. [PMID: 9727627 DOI: 10.1046/j.1525-1500.1998.00054.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Oligosaccharide moieties of cell-surface glycoproteins are thought to be involved in recognition events during cancer metastasis and invasion. Swainsonine, an inhibitor of the Golgi alpha-mannosidase II, has been shown to block pulmonary colonization by tumor cells and stimulate components of the immune system. Swainsonine also abrogates much of the toxicity of chemotherapeutic agents and stimulates bone marrow hematopoietic progenitor cells, suggesting additional therapeutic applications. We are currently characterizing the ability of swainsonine to modify cell growth in human and murine bone marrow progenitor cells. Furthermore, we are examining crucial steps in metastasis that depend upon cell surface molecules that play a role in cell-matrix interactions. Our work shows that tumor cell adhesion to collagen IV in vitro is rapidly stimulated by cis-polyunsaturated fatty acids and is dependent on protein kinase C activity. We are investigating the hypothesis that integrins are critical components of this adhesion and are examining potential signal transduction pathways that lead to the modulation of cell adhesion.
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Affiliation(s)
- J D Roberts
- Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
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Dennis JW, White SL, Freer AM, Dime D. Carbonoyloxy analogs of the anti-metastatic drug swainsonine. Activation in tumor cells by esterases. Biochem Pharmacol 1993; 46:1459-66. [PMID: 8240396 DOI: 10.1016/0006-2952(93)90112-a] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Swainsonine (SW), a plant alkaloid and inhibitor of alpha-mannosidases, has been shown to inhibit N-linked oligosaccharide processing and to block tumor cell metastasis in mice. In this study, a series of SW analogs were chemically synthesized and compared for inhibition of complex-type N-linked oligosaccharide processing in cultured MDAY-D2 tumor cells, for inhibition of alpha-mannosidases in vitro, and for stimulation of bone marrow proliferation in vivo. Carbonoyloxy substitutions at the 2 and 8 carbons of SW reduced inhibitor activity by 2-3 orders of magnitude for Jack Bean and MDAY-D2 tumor cell lysosomal alpha-mannosidases in vitro. However, 2-p-nitrobenzoyloxy-, 2-octanoyloxy- and 2-butanoyloxy-derivatives of SW retained full activity as inhibitors of Golgi oligosaccharide processing in viable MDAY-D2 tumor cells. Inhibition of oligosaccharide processing was reduced by the esterase inhibitor diethyl p-nitrophenyl phosphate, suggesting that although 2-p-nitrobenzoyloxy-SW, 2-octanoyloxy-SW and 2-butanoyloxy-SW are relatively poor inhibitors of alpha-mannosidases in vitro, the compounds enter cells at a rate comparable to that of SW, and are converted to SW by cellular esterases. The more lipophilic esters, 2-benzoyloxy-SW, 2-toluoyloxy-SW, 8-palmitoyloxy-SW and 8-myristinoyloxy-SW, showed IC50 values at least 10 times higher for inhibition of Golgi oligosaccharide processing, probably due to less efficient entry of the compounds into tumor cells. The anti-metastatic activities of SW and two analogs were tested and shown to correlate with the IC50 values for inhibition of Golgi oligosaccharide processing in cultured tumor cells. In vivo, SW and the analogs were administered intraperitoneally to mice and found to have comparable activities as stimulators of bone marrow cell proliferation. Carbonoyloxy substitutions at the 2- or 8-position of SW with other chemical groups may lead to new drugs with improved pharmacokinetics and anti-cancer activity.
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Affiliation(s)
- J W Dennis
- Samuel Lunenfeld Research Institute, Mt. Sinai Hospital, Toronto, Ontario, Canada
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Kang MS, Bowlin TL, Vijay IK, Sunkara SP. Accumulation of pentamannose oligosaccharides in human mononuclear leukocytes by action of swainsonine, an inhibitor of glycoprotein processing. Carbohydr Res 1993; 248:327-37. [PMID: 8252542 DOI: 10.1016/0008-6215(93)84138-v] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Swainsonine, a known inhibitor of the alpha-mannosidase II involved in processing of asparagine-linked glycoproteins, causes accumulation of hybrid-type oligosaccharide-containing glycoproteins in mammalian cells. Swainsonine augments lymphokine-activated, killer-cell induction at suboptimal doses of interleukin-2; the amount needed to increase LAK activity is 100-1000 fold higher than required to completely inhibit mannosidase II. Human mononuclear lymphocytes, when treated with these relatively high (58 microM) concentrations of swainsonine showed a 3-4 fold increase in D-[3H]mannose incorporation into the glycan as compared to glycans of untreated cells. Analysis indicated accumulation of high-mannose type, free oligosaccharides in the soluble fractions of the cell. Chromatographic analysis of glycan obtained by D-[2-3H]mannose labeling of human mononuclear lymphocytes showed synthesis of a new oligosaccharide, at 58 microM of swainsonine, that contained 36% of the total radioactivity incorporated into the glycan (oligosaccharide pool). This oligosaccharide fraction was resistant to hydrolysis by endoglycosidase H, endoglycosidase F, O and N-glycanase, but was susceptible to cleavage by Jack bean alpha-mannosidase and was bound > 90% to concanavalin A-Sepharose. A similar chromatographic elution profile was obtained from glycans labeled with D-[2-3H]mannose from mouse B16F10 melanoma and baby hamster kidney cells subsequent to swainsonine treatment. Methylation analysis of free oligosaccharides obtained from MNL revealed the presence of a pentamannose. These results indicate the accumulation of a free high-mannose oligosaccharide rather than expected hybrid-type structure on treatment of cells with relatively high concentrations of swainsonine.
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Affiliation(s)
- M S Kang
- Marion Merrell Dow Research Institute, Cincinnati, OH 45215
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