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Chen Z, Dai W, Xiong M, Gao J, Zhou H, Chen D, Li Y. Metabolomics investigation of the chemical variations in white teas with different producing areas and storage durations. Food Chem X 2024; 21:101127. [PMID: 38292681 PMCID: PMC10825419 DOI: 10.1016/j.fochx.2024.101127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 01/04/2024] [Accepted: 01/05/2024] [Indexed: 02/01/2024] Open
Abstract
In this study, we employed nontargeted metabolomics and quantitative analysis to explore the variations in metabolites among white teas from different production areas and with varying storage durations. A total of 83 compounds exhibited differential levels between Zhenghe and Fuding white tea, 89 between Zhenghe and Jinggu, and 75 between Fuding and Jinggu white tea. Concerning the storage of white tea, the concentrations of flavanols, dimeric catechins, and amino acids decreased over time, while N-ethyl-2-pyrrolidone-substituted flavanols (EPSFs), caffeine, adenosine monophosphate (AMP), and adenosine increased. Galloylated flavanols showed a higher propensity to form EPSFs with theanine compared to nongalloylated flavanols during storage. Theanine and epigallocatechin gallate were more inclined to generate S-configuration EPSFs during storage in Fuding and Jinggu white tea samples, while R-configuration EPSFs were more readily formed in Zhenghe white tea samples. This study offers a comprehensive understanding of the changes in metabolites during the storage of white tea.
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Affiliation(s)
- Zewen Chen
- College of Tea, Yunnan Agricultural University, Kunming, Yunnan, 650201, China
| | - Weidong Dai
- Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, Zhejiang 310008, China
| | - Mengfan Xiong
- College of Tea, Yunnan Agricultural University, Kunming, Yunnan, 650201, China
| | - Jianjian Gao
- Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, Zhejiang 310008, China
| | - Hongjie Zhou
- College of Tea, Yunnan Agricultural University, Kunming, Yunnan, 650201, China
| | - Dan Chen
- Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, Zhejiang 310008, China
| | - Yali Li
- College of Tea, Yunnan Agricultural University, Kunming, Yunnan, 650201, China
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Zhang S, Kou X, Zhao H, Mak KK, Balijepalli MK, Pichika MR. Zingiber officinale var. rubrum: Red Ginger's Medicinal Uses. Molecules 2022; 27:775. [PMID: 35164040 PMCID: PMC8840670 DOI: 10.3390/molecules27030775] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 01/18/2022] [Accepted: 01/18/2022] [Indexed: 11/17/2022] Open
Abstract
Zingiber officinale var. rubrum (red ginger) is widely used in traditional medicine in Asia. Unlike other gingers, it is not used as a spice in cuisines. To date, a total of 169 chemical constituents have been reported from red ginger. The constituents include vanilloids, monoterpenes, sesquiterpenes, diterpenes, flavonoids, amino acids, etc. Red ginger has many therapeutic roles in various diseases, including inflammatory diseases, vomiting, rubella, atherosclerosis, tuberculosis, growth disorders, and cancer. Scientific evidence suggests that red ginger exhibits immunomodulatory, antihypertensive, antihyperlipidemic, antihyperuricemic, antimicrobial, and cytotoxic activities. These biological activities are the underlying causes of red ginger's therapeutic benefits. In addition, there have been few reports on adverse side effects of red ginger. This review aims to provide insights in terms the bioactive constituents and their biosynthesis, biological activities, molecular mechanisms, pharmacokinetics, and qualitative and quantitative analysis of red ginger.
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Affiliation(s)
- Shiming Zhang
- School of Postgraduate Studies, International Medical University, Kuala Lumpur 57000, Malaysia; (S.Z.); (K.-K.M.)
| | - Xuefang Kou
- Experimental Centre, Shandong University of Traditional Chinese Medicine, Jinan 250355, China;
| | - Hui Zhao
- School of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan 250355, China;
| | - Kit-Kay Mak
- School of Postgraduate Studies, International Medical University, Kuala Lumpur 57000, Malaysia; (S.Z.); (K.-K.M.)
- Pharmaceutical Chemistry Department, School of Pharmacy, International Medical University, Kuala Lumpur 57000, Malaysia
- Centre for Bioactive Molecules and Drug Delivery, Institute for Research, Development & Innovation (IRDI), International Medical University, Kuala Lumpur 57000, Malaysia
| | - Madhu Katyayani Balijepalli
- Department of Pharmacology, Faculty of Medicine and Health Sciences, MAHSA University, Selangor 42610, Malaysia;
| | - Mallikarjuna Rao Pichika
- Pharmaceutical Chemistry Department, School of Pharmacy, International Medical University, Kuala Lumpur 57000, Malaysia
- Centre for Bioactive Molecules and Drug Delivery, Institute for Research, Development & Innovation (IRDI), International Medical University, Kuala Lumpur 57000, Malaysia
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Mdivi-1 induces spindle abnormalities and augments taxol cytotoxicity in MDA-MB-231 cells. Cell Death Discov 2021; 7:118. [PMID: 34016960 PMCID: PMC8137698 DOI: 10.1038/s41420-021-00495-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/03/2021] [Accepted: 04/23/2021] [Indexed: 01/19/2023] Open
Abstract
Taxol is a first-line chemotherapeutic for numerous cancers, including the highly refractory triple-negative breast cancer (TNBC). However, it is often associated with toxic side effects and chemoresistance in breast cancer patients, which greatly limits the clinical utility of the drug. Hence, compounds that act in concert with taxol to promote cytotoxicity may be useful to improve the efficacy of taxol-based chemotherapy. In this study, we demonstrated that mdivi-1, a putative inhibitor of mitochondrial fission protein Drp1, enhances the anticancer effects of taxol and overcomes taxol resistance in a TNBC cell line (MDA-MB-231). Not only did mdivi-1 induce mitotic spindle abnormalities and mitotic arrest when used alone, but it also enhanced taxol-induced antimitotic effects when applied in combination. In addition, mdivi-1 induced pronounced spindle abnormalities and cytotoxicity in a taxol-resistant cell line, indicating that it can overcome taxol resistance. Notably, the antimitotic effects of mdivi-1 were not accompanied by prominent morphological or functional alterations in mitochondria and were Drp1-independent. Instead, mdivi-1 exhibited affinity to tubulin at μM level, inhibited tubulin polymerization, and immediately disrupted spindle assembly when cells entered mitosis. Together, our results show that mdivi-1 associates with tubulin and impedes tubulin polymerization, actions which may underlie its antimitotic activity and its ability to enhance taxol cytotoxicity and overcome taxol resistance in MDA-MB-231 cells. Furthermore, our data imply a possibility that mdivi-1 could be useful to improve the therapeutic efficacy of taxol in breast cancer.
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Malarz K, Mularski J, Kuczak M, Mrozek-Wilczkiewicz A, Musiol R. Novel Benzenesulfonate Scaffolds with a High Anticancer Activity and G2/M Cell Cycle Arrest. Cancers (Basel) 2021; 13:cancers13081790. [PMID: 33918637 PMCID: PMC8068801 DOI: 10.3390/cancers13081790] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/06/2021] [Accepted: 04/07/2021] [Indexed: 12/12/2022] Open
Abstract
Sulfonates, unlike their derivatives, sulphonamides, have rarely been investigated for their anticancer activity. Unlike the well-known sulphonamides, esters are mainly used as convenient intermediates in a synthesis. Here, we present the first in-depth investigation of quinazoline sulfonates. A small series of derivatives were synthesized and tested for their anticancer activity. Based on their structural similarity, these compounds resemble tyrosine kinase inhibitors and the p53 reactivator CP-31398. Their biological activity profile, however, was more related to sulphonamides because there was a strong cell cycle arrest in the G2/M phase. Further investigation revealed a multitargeted mechanism of the action that corresponded to the p53 protein status in the cell. Although the compounds expressed a high submicromolar activity against leukemia and colon cancers, pancreatic cancer and glioblastoma were also susceptible. Apoptosis and autophagy were confirmed as the cell death modes that corresponded with the inhibition of metabolic activity and the activation of the p53-dependent and p53-independent pathways. Namely, there was a strong activation of the p62 protein and GADD44. Other proteins such as cdc2 were also expressed at a higher level. Moreover, the classical caspase-dependent pathway in leukemia was observed at a lower concentration, which again confirmed a multitargeted mechanism. It can therefore be concluded that the sulfonates of quinazolines can be regarded as promising scaffolds for developing anticancer agents.
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Affiliation(s)
- Katarzyna Malarz
- A. Chełkowski Institute of Physics and Silesian Centre for Education and Interdisciplinary Research, University of Silesia in Katowice, 75 Pułku Piechoty 1a, 41-500 Chorzów, Poland; (M.K.); (A.M.-W.)
- Correspondence: (K.M.); (R.M.)
| | - Jacek Mularski
- Institute of Chemistry, University of Silesia in Katowice, 75 Pułku Piechoty 1a, 41-500 Chorzów, Poland;
| | - Michał Kuczak
- A. Chełkowski Institute of Physics and Silesian Centre for Education and Interdisciplinary Research, University of Silesia in Katowice, 75 Pułku Piechoty 1a, 41-500 Chorzów, Poland; (M.K.); (A.M.-W.)
- Institute of Chemistry, University of Silesia in Katowice, 75 Pułku Piechoty 1a, 41-500 Chorzów, Poland;
| | - Anna Mrozek-Wilczkiewicz
- A. Chełkowski Institute of Physics and Silesian Centre for Education and Interdisciplinary Research, University of Silesia in Katowice, 75 Pułku Piechoty 1a, 41-500 Chorzów, Poland; (M.K.); (A.M.-W.)
| | - Robert Musiol
- Institute of Chemistry, University of Silesia in Katowice, 75 Pułku Piechoty 1a, 41-500 Chorzów, Poland;
- Correspondence: (K.M.); (R.M.)
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Bai X, Wang WX, Fu RJ, Yue SJ, Gao H, Chen YY, Tang YP. Therapeutic Potential of Hydroxysafflor Yellow A on Cardio-Cerebrovascular Diseases. Front Pharmacol 2020; 11:01265. [PMID: 33117148 PMCID: PMC7550755 DOI: 10.3389/fphar.2020.01265] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 07/30/2020] [Indexed: 12/15/2022] Open
Abstract
The incidence rate of cardio-cerebrovascular diseases (CCVDs) is increasing worldwide, causing an increasingly serious public health burden. The pursuit of new promising treatment options is thus becoming a pressing issue. Hydroxysafflor yellow A (HSYA) is one of the main active quinochalcone C-glycosides in the florets of Carthamus tinctorius L., a medical and edible dual-purpose plant. HSYA has attracted much interest for its pharmacological actions in treating and/or managing CCVDs, such as myocardial and cerebral ischemia, hypertension, atherosclerosis, vascular dementia, and traumatic brain injury, in massive preclinical studies. In this review, we briefly summarized the mode and mechanism of action of HSYA on CCVDs based on these preclinical studies. The therapeutic effects of HSYA against CCVDs were presumed to reside mostly in its antioxidant, anti-inflammatory, and neuroprotective roles by acting on complex signaling pathways.
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Affiliation(s)
- Xue Bai
- Key Laboratory of Shaanxi Administration of Traditional Chinese Medicine for TCM Compatibility, and State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, and Shaanxi Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Shaanxi University of Chinese Medicine, Xi'an, China
| | - Wen-Xiao Wang
- Key Laboratory of Shaanxi Administration of Traditional Chinese Medicine for TCM Compatibility, and State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, and Shaanxi Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Shaanxi University of Chinese Medicine, Xi'an, China
| | - Rui-Jia Fu
- Key Laboratory of Shaanxi Administration of Traditional Chinese Medicine for TCM Compatibility, and State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, and Shaanxi Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Shaanxi University of Chinese Medicine, Xi'an, China
| | - Shi-Jun Yue
- Key Laboratory of Shaanxi Administration of Traditional Chinese Medicine for TCM Compatibility, and State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, and Shaanxi Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Shaanxi University of Chinese Medicine, Xi'an, China
| | - Huan Gao
- Key Laboratory of Shaanxi Administration of Traditional Chinese Medicine for TCM Compatibility, and State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, and Shaanxi Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Shaanxi University of Chinese Medicine, Xi'an, China
| | - Yan-Yan Chen
- Key Laboratory of Shaanxi Administration of Traditional Chinese Medicine for TCM Compatibility, and State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, and Shaanxi Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Shaanxi University of Chinese Medicine, Xi'an, China
| | - Yu-Ping Tang
- Key Laboratory of Shaanxi Administration of Traditional Chinese Medicine for TCM Compatibility, and State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, and Shaanxi Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Shaanxi University of Chinese Medicine, Xi'an, China
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Derivatives of 6-cinnamamido-quinoline-4-carboxamide impair lysosome function and induce apoptosis. Oncotarget 2018; 7:38078-38090. [PMID: 27191263 PMCID: PMC5122373 DOI: 10.18632/oncotarget.9348] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 05/02/2016] [Indexed: 01/04/2023] Open
Abstract
Autophagy is a lysosomal degradative process that protects cancer cells from multiple types of stress. In this study, we synthesized a series of derivatives of 6-cinnamamido-quinoline-4-carboxamide (CiQ), and investigated their effects on the proliferation and autophagy of cancer cells in vitro. These derivatives effectively inhibited the proliferation of a broad spectrum of cancer cell lines. Further study revealed that CiQ derivatives may induce autophagy and result in disruption of autophagy propagation. Consequently, these derivatives triggered massive apoptosis, as evidenced by caspase-9 activation and PARP cleavage. Blockage of autophagy by depletion of autophagy related gene ATG5 or BECN1 considerably alleviated CiQ-induced cell death, indicating that autophagy may mediate CiQ-induced cell death. Furthermore, treatment with CiQ derivatives increased lysosome membrane permeability (LMP) and enhanced accumulation of ubiquitinated proteins, which collectively indicate impaired lysosome function. In addition, treatment of cells with CiQ derivatives activated extracellular signal-regulated kinase (ERK); abrogation of ERK activation, either by treating cells with U0126, an inhibitor of mitogen-activated protein/ERK kinase 1 (MEK1), or by ectopically overexpressing a dominant-negative MEK1, significantly reduced CiQ derivative-induced LMP, LC3 and p62 accumulation, and cytotoxicity. These results indicate that CiQ derivatives activate ERK and disrupt lysosome function, thereby altering autophagic flux and resulting in apoptotic cell death.
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Jantová S, Paulovičová E, Paulovičová L, Topoľská D, Pánik M, Milata V. Assessment of Immunomodulatory Activities andin vitroToxicity of New Quinolone 7-ethyl 9-ethyl-6-oxo-6,9-dihydro[1,2,5]selenadiazolo[3,4-h]quinoline-7-carboxylate. Immunol Invest 2017; 46:341-360. [DOI: 10.1080/08820139.2017.1280050] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Chen YJ, Lai KC, Kuo HH, Chow LP, Yih LH, Lee TC. HSP70 colocalizes with PLK1 at the centrosome and disturbs spindle dynamics in cells arrested in mitosis by arsenic trioxide. Arch Toxicol 2014; 88:1711-23. [PMID: 24623308 DOI: 10.1007/s00204-014-1222-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 03/03/2014] [Indexed: 11/26/2022]
Abstract
Heat shock protein 70 (HSP70) has been shown to be a substrate of Polo-like kinase 1 (PLK1), and it prevents cells arrested in mitosis by arsenic trioxide (ATO) from dying. Here, we report that HSP70 participates in ATO-induced spindle elongation, which interferes with mitosis progression. Our results demonstrate that HSP70 and PLK1 colocalize at the centrosome in ATO-arrested mitotic cells. HSP70 located at the centrosome was found to be phosphorylated by PLK1 at Ser⁶³¹ and Ser⁶³³. Moreover, unlike wild-type HSP70 (HSP70(wt)) and its phosphomimetic mutant (HSP70(SS631,633DD)), a phosphorylation-resistant mutant of HSP70 (HSP70(SS631,633AA)) failed to localize at the centrosome. ATO-induced spindle elongation was abolished in cells overexpressing HSP70(SS631,633AA). Conversely, mitotic spindles in cells ectopically expressing HSP70(SS631,633DD) were more resistant to nocodazole-induced depolymerization than in those expressing HSP70(wt) or HSP70(SS631,633AA). In addition, inhibition of PLK1 significantly reduced HSP70 phosphorylation and induced early onset of apoptosis in ATO-arrested mitotic cells. Taken together, our results indicate that PLK1-mediated phosphorylation and centrosomal localization of HSP70 may interfere with spindle dynamics and prevent apoptosis of ATO-arrested mitotic cells.
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Affiliation(s)
- Yu-Ju Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, 11529, Taiwan
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Yih LH, Wu YC, Hsu NC, Kuo HH. Arsenic trioxide induces abnormal mitotic spindles through a PIP4KIIγ/Rho pathway. Toxicol Sci 2012; 128:115-25. [PMID: 22496355 DOI: 10.1093/toxsci/kfs129] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Arsenite-induced spindle abnormalities result in mitotic cell apoptosis in several cancer cell lines, but how arsenite induces these effects is not known. Evidence to date has revealed that arsenite activates Rho guanosine triphosphatases (GTPases). Because Rho GTPases regulate spindle orientation, chromosome congression, and cytokinesis, we therefore examined the involvement of Rho GTPases and their modulators in arsenite-induced mitotic abnormalities. We demonstrated that arsenic trioxide (ATO) disrupted the positioning of bipolar mitotic spindles and induced centrosome and spindle abnormalities. ATO increased the level of the active guanosine triphosphate-bound form of Rho. Inhibition of Rho-associated protein kinases (ROCKs) by Y-27632 ameliorated ATO-induced spindle defects, mitotic arrest, and cell death. These results indicate that ATO may induce spindle abnormalities and mitotic cell death through a Rho/ROCK pathway. In addition, screening of a human kinase and phosphatase shRNA library to select genes that mediate ATO induction of spindle abnormalities resulted in the identification of phosphatidylinositol-5-phosphate 4-kinase type-2 gamma (PIP4KIIγ), a phosphatidylinositol 4,5-biphosphate (PIP2) synthesis enzyme that belongs to the phosphatidylinositol phosphate kinase (PIPK) family. Sequestration of PIP2 by ectopic overexpression of the pleckstrin homology domain of phospholipase C-δ1 protected cells from ATO-induced cell death. Furthermore, depletion of PIP4KIIγ, but not other isoforms of the PIPK family, not only reduced Rho GTPase activation in ATO-treated cells but also alleviated ATO-induced spindle defects, mitotic arrest, and mitotic cell apoptosis. Thus, our results imply that ATO induces abnormalities in mitotic spindles through a PIP4KIIγ/Rho pathway, leading to apoptosis of mitotic cells.
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Affiliation(s)
- Ling-Huei Yih
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan, Republic of China.
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Yih LH, Hsu NC, Kuo HH, Wu YC. Inhibition of the heat shock response by PI103 enhances the cytotoxicity of arsenic trioxide. Toxicol Sci 2012; 128:126-36. [PMID: 22496356 DOI: 10.1093/toxsci/kfs130] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Heat shock factor 1 (HSF1) is a key regulator of the cytoprotective and anti-apoptotic heat shock response and can be activated by arsenite. Inhibition of HSF1 activation may therefore enhance the cytotoxicity of arsenic trioxide (ATO). We show that ATO induced HSF1 phosphorylation at serine 326 (S326) and induced HSF1-dependent expression of heat shock proteins (HSPs) 27 and 70 in cultured cells. HSF1 significantly reduced cell sensitivity to ATO by reducing apoptosis. Disruption of HSF1 function not only reduced ATO induction of HSP27 and 70 but also enhanced ATO cytotoxicity by elevating apoptosis. These results reveal that HSF1 activation and the resulting induction of HSPs may protect cells from ATO cytotoxicity. The diminished expression of HSPs and hypersensitivity to ATO in cells stably depleted of HSF1 was rescued by ectopic expression of wild-type HSF1 but not an S326A substitution mutant, indicating that phosphorylation at S326 was critical for the protective effect of HSF1. Simultaneous treatment of cells with ATO and PI103, an inhibitor of members of the phosphatidylinositol 3-kinase (PI3K) family, suppressed not only ATO-induced expression of an HSP70 promoter-reporter construct and endogenous HSP70 but also phosphorylation of HSF1 S326. PI103 considerably reduced HSF1 transactivation in ATO-treated cells but had only a limited effect on HSF1 nuclear translocation and DNA binding. Furthermore, PI103 enhanced ATO cytotoxicity in an HSF1-dependent manner. Thus, inhibition of S326 phosphorylation by PI103 blocks the transactivation of HSF1 and may consequently suppress ATO induction of the heat shock response and sensitize cells to ATO.
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Affiliation(s)
- Ling-Huei Yih
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan, Republic of China.
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