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Rhaponticin suppresses the hypoxia-induced factor-1 alpha-mediated aggressive phenotype of tongue squamous cell carcinoma. Mol Cell Toxicol 2023. [DOI: 10.1007/s13273-023-00337-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
Abstract
Background
Emerging evidence suggests that rhaponticin, a stilbene monomeric compound isolated from North China rhubarb, has been shown to exhibit significant biological activity against tumors. However, the anticancer effects and mechanisms of rhaponticin in tongue squamous cell carcinoma (TSCC) remain elusive.
Objective
We investigated the changes of migration and invasion abilities and EMT progression of TSCC cells treated with different concentrations of rhaponticin under hypoxia, as well as the possible mechanisms, in order to initially explore the effects of rhaponticin on the biological characteristics of TSCC cells under hypoxia.
Results
The number of cell migration and invasion was prominently increased, E-cadherin protein was down-regulated, and N-cadherin and HIF-1α protein expression was elevated under hypoxia. Rhaponticin intervention strikingly prevented the increased abilities of migration and invasion and EMT of TSCC cells under hypoxia. This was followed by further validation finding that rhaponticin indeed leads to reduced HIF-1α post-transcriptional activity. Mechanistically, rhaponticin may bind to aryl-hydrocarbon nuclear translocator (ARNT) domain of HIF-1α.
Conclusions
Rhaponticin repressed the invasion and migration abilities and EMT process of TSCC cells under a hypoxic environment in vitro by targeted suppression of HIF-1α.
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Jie YK, Cheng CH, Wang LC, Ma HL, Deng YQ, Liu GX, Feng J, Guo ZX, Ye LT. Hypoxia-induced oxidative stress and transcriptome changes in the mud crab (Scylla paramamosain). Comp Biochem Physiol C Toxicol Pharmacol 2021; 245:109039. [PMID: 33785424 DOI: 10.1016/j.cbpc.2021.109039] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/04/2021] [Accepted: 03/20/2021] [Indexed: 02/08/2023]
Abstract
Mud crab (Scylla paramamosain) is an economically important cultured species in China. Hypoxia is a major environmental stressor during mud crab culture. In the present study, we investigated the oxidative stress and transcriptome changes in the gills of mud crab after intermediate hypoxia stress with dissolved oxygen (DO) 3.0 ± 0.2 mg/L (named as "DO3") and acute hypoxia stress with DO 1.0 ± 0.2 mg/L (named as "DO1") for 0, 3, 6, 12 and 24 h. The superoxide dismutase (SOD) activity of DO1 increased significantly at 3, 6 and 24 h after hypoxia stress, while SOD activity of DO3 increased significantly at 6 and 24 h. The total antioxidant capacity (T-AOC) increased significantly at 6, 12 and 24 h after hypoxia stress. The malondialdehyde (MDA) concentration of DO1 increased significantly at 6, 12 and 24 h after hypoxia stress, while MDA concentration of DO3 only increased significantly at 6 h. The lactate dehydrogenase (LDH) activity of DO1 increased significantly at 3, 6, 12 and 24 h after hypoxia stress, while LDH activity of DO3 increased significantly at 12 and 24 h. Transcriptomic analysis was conducted at 24 h of gill tissues after hypoxia stress. A total of 1052 differentially expressed genes (DEGs) were obtained, including 394 DEGs between DO1 and DO3, 481 DEGs between DO1 and control group, 177 DEGs between DO3 and control group. DEGs were enriched in the pathways related to metabolism, immune functions, ion transport, and signal transduction. Transcriptional analysis showed that glycolysis and tricarboxylic acid cycle genes were the key factors in regulating the adaptation of mud crab to hypoxia stress.
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Affiliation(s)
- Yu-Kun Jie
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China; Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China
| | - Chang-Hong Cheng
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China.
| | - Li-Cang Wang
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China
| | - Hong-Ling Ma
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China
| | - Yi-Qin Deng
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China
| | - Guang-Xin Liu
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China
| | - Juan Feng
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China
| | - Zhi-Xun Guo
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China.
| | - Ling-Tong Ye
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China
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Taheem DK, Jell G, Gentleman E. Hypoxia Inducible Factor-1α in Osteochondral Tissue Engineering. TISSUE ENGINEERING. PART B, REVIEWS 2020; 26:105-115. [PMID: 31774026 PMCID: PMC7166133 DOI: 10.1089/ten.teb.2019.0283] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 11/19/2019] [Indexed: 12/19/2022]
Abstract
Damage to osteochondral (OC) tissues can lead to pain, loss of motility, and progress to osteoarthritis. Tissue engineering approaches offer the possibility of replacing damaged tissues and restoring joint function; however, replicating the spatial and functional heterogeneity of native OC tissue remains a pressing challenge. Chondrocytes in healthy cartilage exist in relatively low-oxygen conditions, while osteoblasts in the underlying bone experience higher oxygen pressures. Such oxygen gradients also exist in the limb bud, where they influence OC tissue development. The cellular response to these spatial variations in oxygen pressure, which is mediated by the hypoxia inducible factor (HIF) pathway, plays a central role in regulating osteo- and chondrogenesis by directing progenitor cell differentiation and promoting and maintaining appropriate extracellular matrix production. Understanding the role of the HIF pathway in OC tissue development may enable new approaches to engineer OC tissue. In this review, we discuss strategies to spatially and temporarily regulate the HIF pathway in progenitor cells to create functional OC tissue for regenerative therapies. Impact statement Strategies to engineer osteochondral (OC) tissue are limited by the complex and varying microenvironmental conditions in native bone and cartilage. Indeed, native cartilage experiences low-oxygen conditions, while the underlying bone is relatively normoxic. The cellular response to these low-oxygen conditions, which is mediated through the hypoxia inducible factor (HIF) pathway, is known to promote and maintain the chondrocyte phenotype. By using tissue engineering scaffolds to spatially and temporally harness the HIF pathway, it may be possible to improve OC tissue engineering strategies for the regeneration of damaged cartilage and its underlying subchondral bone.
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Affiliation(s)
- Dheraj K. Taheem
- Centre for Craniofacial and Regenerative Biology, King's College London, London, United Kingdom
| | - Gavin Jell
- Division of Surgery and Interventional Sciences, University College London, London, United Kingdom
| | - Eileen Gentleman
- Centre for Craniofacial and Regenerative Biology, King's College London, London, United Kingdom
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Shemarova IV, Nesterov VP. Molecular Basis of Cardioprotection in Ischemic Heart Disease. J EVOL BIOCHEM PHYS+ 2019. [DOI: 10.1134/s0022093019030013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Asakawa S, Onodera R, Kasai K, Kishimoto Y, Sato T, Segawa R, Mizuno N, Ogasawara K, Moriya T, Hiratsuka M, Hirasawa N. Nickel ions bind to HSP90β and enhance HIF-1α-mediated IL-8 expression. Toxicology 2018; 395:45-53. [PMID: 29355601 DOI: 10.1016/j.tox.2018.01.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 01/04/2018] [Accepted: 01/12/2018] [Indexed: 01/07/2023]
Abstract
Nickel ions (Ni2+) eluted from biomedical devices cause inflammation and Ni allergy. Although Ni2+ and Co2+ elicit common effects, Ni2+ induces a generally stronger inflammatory reaction. However, the molecular mechanism by which Ni2+ and Co2+ induce such different responses remains to be elucidated. In the present study, we compared the effects of Ni2+ and Co2+ on the expression of interleukin (IL)-8 in human monocyte THP-1 cells. We report that NiCl2 but not CoCl2 induced the expression of IL-8; in contrast, CoCl2 elicited a higher expression of hypoxia-inducible factor-1α (HIF-1α). The NiCl2-induced expression of IL-8 in late phase was blocked by a HIF-1α inhibitor, PX-478, indicating that NiCl2 targets additional factors responsible for activating HIF-1α. To identify such targets, proteins that bound preferentially to Ni-NTA beads were analyzed by LC/MS/MS. The analysis yielded heat shock protein 90β (HSP90β) as a possible candidate. Furthermore, Ni2+ reduced the interaction of HSP90β with HIF-1α, and instead promoted the interaction between HIF-1α and HIF-1β, as well as the nuclear localization of HIF-1α. Using various deletion variants, we showed that Ni2+ could bind to the linker domain on HSP90β. These results suggest that HSP90β plays important roles in Ni2+-induced production of IL-8 and could be a potential target for the regulation of Ni2+-induced inflammation.
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Affiliation(s)
- Sanki Asakawa
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Ryo Onodera
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Koji Kasai
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Yu Kishimoto
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Taiki Sato
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Ryosuke Segawa
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Natsumi Mizuno
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Kouetsu Ogasawara
- Department of Immunobiology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Miyagi, Japan
| | - Takahiro Moriya
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Masahiro Hiratsuka
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Noriyasu Hirasawa
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan.
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Crouch B, Murphy H, Belonwu S, Martinez A, Gallagher J, Hall A, Soo MS, Lee M, Hughes P, Haystead T, Ramanujam N. Leveraging ectopic Hsp90 expression to assay the presence of tumor cells and aggressive tumor phenotypes in breast specimens. Sci Rep 2017; 7:17487. [PMID: 29235516 PMCID: PMC5727497 DOI: 10.1038/s41598-017-17832-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 11/27/2017] [Indexed: 01/02/2023] Open
Abstract
Hsp90 has been studied extensively as a therapeutic target in breast cancer in pre-clinical and clinical trials, demonstrating a variety of roles in metastatic progression. The evidence to date suggests a compelling opportunity to leverage attributes of Hsp90 expression beyond therapeutics with potential applications in breast cancer diagnosis, prognosis, and recurrence risk assessment. In this study, we developed a completely non-destructive strategy using HS-27, a fluorescently-tethered Hsp90 inhibitor, to assay Hsp90 expression on intact tissue specimens with comparable contrast to in vivo administration routes, and demonstrate the feasibility of our approach in breast cancer patients. In addition to Hsp90 inhibition being most effective in glycolytic tumors, we found ectopic Hsp90 expression to be highest in glycolytic tumors reinforcing its role as an indicator of aggressive disease. This work sets the stage for immediately using Hsp90 to improve outcomes for breast cancer patients without affecting traditional care pathways.
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Affiliation(s)
- Brian Crouch
- Department of Biomedical Engineering, Duke University, Durham, NC 27710, USA.
| | - Helen Murphy
- Department of Biomedical Engineering, Duke University, Durham, NC 27710, USA
| | - Stella Belonwu
- Duke University Trinity College of Arts and Sciences, Durham, NC 27710, USA
| | - Amy Martinez
- Department of Biomedical Engineering, Duke University, Durham, NC 27710, USA
| | - Jennifer Gallagher
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
| | - Allison Hall
- Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA
| | - Mary Scott Soo
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Marianne Lee
- Department of Biomedical Engineering, Duke University, Durham, NC 27710, USA
| | - Philip Hughes
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Timothy Haystead
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Nirmala Ramanujam
- Department of Biomedical Engineering, Duke University, Durham, NC 27710, USA.,Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
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Mikami H, Saito Y, Okamoto N, Kakihana A, Kuga T, Nakayama Y. Requirement of Hsp105 in CoCl 2-induced HIF-1α accumulation and transcriptional activation. Exp Cell Res 2017; 352:225-233. [PMID: 28185835 DOI: 10.1016/j.yexcr.2017.02.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 01/29/2017] [Accepted: 02/05/2017] [Indexed: 10/20/2022]
Abstract
The mammalian stress protein Hsp105α protects cells from stress conditions. Several studies have indicated that Hsp105α is overexpressed in many types of solid tumors, which contain hypoxic microenvironments. However, the role of Hsp105α in hypoxic tumors remains largely unknown. We herein demonstrated the involvement of Hsp105α in HIF-1 functions induced by the hypoxia-mimetic agent CoCl2. While Hsp105α is mainly localized in the cytoplasm under normal conditions, a treatment with CoCl2 induces the nuclear localization of Hsp105α, which correlated with HIF-1α expression levels. The overexpression of degradation-resistant HIF-1α enhances the nuclear localization of Hsp105α without the CoCl2 treatment. The CoCl2-dependent transcriptional activation of HIF-1, which is measured using a reporter gene containing a HIF-responsive element, is reduced by the knockdown of Hsp105α. Furthermore, the CoCl2-induced accumulation of HIF-1α is enhanced by heat shock, which results in the nuclear localization of Hsp105, and is suppressed by the knockdown of Hsp105. Hsp105 associates with HIF-1α in CoCl2-treated cells. These results suggest that Hsp105α plays an important role in the functions of HIF-1 under hypoxic conditions, in which Hsp105α enhances the accumulation and transcriptional activity of HIF-1 through the HIF-1α-mediated nuclear localization of Hsp105α.
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Affiliation(s)
- Hiroki Mikami
- Department of Biochemistry and Molecular Biology, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto 607-8414, Japan
| | - Youhei Saito
- Department of Biochemistry and Molecular Biology, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto 607-8414, Japan.
| | - Namiko Okamoto
- Department of Biochemistry and Molecular Biology, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto 607-8414, Japan
| | - Ayana Kakihana
- Department of Biochemistry and Molecular Biology, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto 607-8414, Japan
| | - Takahisa Kuga
- Department of Biochemistry and Molecular Biology, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto 607-8414, Japan
| | - Yuji Nakayama
- Department of Biochemistry and Molecular Biology, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto 607-8414, Japan.
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8
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Filatova A, Seidel S, Böğürcü N, Gräf S, Garvalov BK, Acker T. Acidosis Acts through HSP90 in a PHD/VHL-Independent Manner to Promote HIF Function and Stem Cell Maintenance in Glioma. Cancer Res 2016; 76:5845-5856. [PMID: 27488520 DOI: 10.1158/0008-5472.can-15-2630] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 07/13/2016] [Indexed: 11/16/2022]
Abstract
Hypoxia is a common feature of solid tumors, which controls multiple aspects of cancer progression. One important function of hypoxia and the hypoxia-inducible factors (HIF) is the maintenance of cancer stem-like cells (CSC), a population of tumor cells that possess stem cell-like properties and drives tumor growth. Among the changes promoted by hypoxia is a metabolic shift resulting in acidification of the tumor microenvironment. Here, we show that glioma hypoxia and acidosis functionally cooperate in inducing HIF transcription factors and CSC maintenance. We found that these effects did not involve the classical PHD/VHL pathway for HIF upregulation, but instead involved the stress-induced chaperone protein HSP90. Genetic or pharmacologic inactivation of HSP90 inhibited the increase in HIF levels and abolished the self-renewal and tumorigenic properties of CSCs induced by acidosis. In clinical specimens of glioma, HSP90 was upregulated in the hypoxic niche and was correlated with a CSC phenotype. Our findings highlight the role of tumor acidification within the hypoxic niche in the regulation of HIF and CSC function through HSP90, with implications for therapeutic strategies to target CSC in gliomas and other hypoxic tumors. Cancer Res; 76(19); 5845-56. ©2016 AACR.
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Affiliation(s)
- Alina Filatova
- Institute of Neuropathology, University of Giessen, Giessen, Germany
| | - Sascha Seidel
- Institute of Neuropathology, University of Giessen, Giessen, Germany. Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Frankfurt, Germany
| | - Nuray Böğürcü
- Institute of Neuropathology, University of Giessen, Giessen, Germany
| | - Sabine Gräf
- Institute of Neuropathology, University of Giessen, Giessen, Germany
| | - Boyan K Garvalov
- Institute of Neuropathology, University of Giessen, Giessen, Germany
| | - Till Acker
- Institute of Neuropathology, University of Giessen, Giessen, Germany.
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9
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Phelan JP, Reen FJ, Dunphy N, O'Connor R, O'Gara F. Bile acids destabilise HIF-1α and promote anti-tumour phenotypes in cancer cell models. BMC Cancer 2016; 16:476. [PMID: 27416726 PMCID: PMC4946243 DOI: 10.1186/s12885-016-2528-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 07/06/2016] [Indexed: 12/22/2022] Open
Abstract
Background The role of the microbiome has become synonymous with human health and disease. Bile acids, as essential components of the microbiome, have gained sustained credibility as potential modulators of cancer progression in several disease models. At physiological concentrations, bile acids appear to influence cancer phenotypes, although conflicting data surrounds their precise physiological mechanism of action. Previously, we demonstrated bile acids destabilised the HIF-1α subunit of the Hypoxic-Inducible Factor-1 (HIF-1) transcription factor. HIF-1 overexpression is an early biomarker of tumour metastasis and is associated with tumour resistance to conventional therapies, and poor prognosis in a range of different cancers. Methods Here we investigated the effects of bile acids on the cancer growth and migratory potential of cell lines where HIF-1α is known to be active under hypoxic conditions. HIF-1α status was investigated in A-549 lung, DU-145 prostate and MCF-7 breast cancer cell lines exposed to bile acids (CDCA and DCA). Cell adhesion, invasion, migration was assessed in DU-145 cells while clonogenic growth was assessed in all cell lines. Results Intracellular HIF-1α was destabilised in the presence of bile acids in all cell lines tested. Bile acids were not cytotoxic but exhibited greatly reduced clonogenic potential in two out of three cell lines. In the migratory prostate cancer cell line DU-145, bile acids impaired cell adhesion, migration and invasion. CDCA and DCA destabilised HIF-1α in all cells and significantly suppressed key cancer progression associated phenotypes; clonogenic growth, invasion and migration in DU-145 cells. Conclusions These findings suggest previously unobserved roles for bile acids as physiologically relevant molecules targeting hypoxic tumour progression.
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Affiliation(s)
- J P Phelan
- BIOMERIT Research Centre, School of Microbiology, University College Cork - National University of Ireland, Cork, Ireland
| | - F J Reen
- BIOMERIT Research Centre, School of Microbiology, University College Cork - National University of Ireland, Cork, Ireland
| | - N Dunphy
- BIOMERIT Research Centre, School of Microbiology, University College Cork - National University of Ireland, Cork, Ireland
| | - R O'Connor
- School of Biochemistry and Cell Biology, University College Cork - National University of Ireland, Cork, Ireland
| | - F O'Gara
- BIOMERIT Research Centre, School of Microbiology, University College Cork - National University of Ireland, Cork, Ireland. .,School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, WA, 6102, Australia.
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Yu L, Wang GD, Ruan J, Chen YB, Yang CP, Cao X, Wu H, Liu YH, Du ZL, Wang XP, Yang J, Cheng SC, Zhong L, Wang L, Wang X, Hu JY, Fang L, Bai B, Wang KL, Yuan N, Wu SF, Li BG, Zhang JG, Yang YQ, Zhang CL, Long YC, Li HS, Yang JY, Irwin DM, Ryder OA, Li Y, Wu CI, Zhang YP. Genomic analysis of snub-nosed monkeys (Rhinopithecus) identifies genes and processes related to high-altitude adaptation. Nat Genet 2016; 48:947-52. [DOI: 10.1038/ng.3615] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 06/13/2016] [Indexed: 12/31/2022]
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A HIF-1α-driven feed-forward loop augments HIF signalling in Hep3B cells by upregulation of ARNT. Cell Death Dis 2016; 7:e2284. [PMID: 27362802 PMCID: PMC5108338 DOI: 10.1038/cddis.2016.187] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 06/01/2016] [Accepted: 06/03/2016] [Indexed: 02/07/2023]
Abstract
Oxygen-deprived (hypoxic) areas are commonly found within neoplasms caused by excessive cell proliferation. The transcription factor Aryl hydrocarbon receptor nuclear translocator (ARNT) is part of the hypoxia-inducible factor (HIF) pathway, which mediates adaptive responses to ensure cellular survival under hypoxic conditions. HIF signalling leads to metabolic alterations, invasion/metastasis and the induction of angiogenesis in addition to radio-chemoresistance of tumour cells. Activation of the HIF pathway is based on the abundance of HIF-α subunits, which are regulated in an oxygen-dependent manner and form transcriptional active complexes with ARNT or ARNT2 (also referred as HIF-1β and HIF-2β, respectively). ARNT is considered to be unaffected by hypoxia but certain cell lines, including Hep3B cells, are capable to elevate this transcription factor in response to oxygen deprivation, which implies an advantage. Therefore, the aim of this study was to elucidate the mechanism of hypoxia-dependent ARNT upregulation and to determine implications on HIF signalling. Gene silencing and overexpression techniques were used to alter the expression pattern of HIF transcription factors under normoxic and hypoxic conditions. qRT-PCR and western blotting were performed to measure gene and protein expression, respectively. HIF activity was determined by reporter gene assays. The results revealed a HIF-1α-dependent mechanism leading to ARNT upregulation in hypoxia. Forced expression of ARNT increased reporter activity under normoxic and hypoxic conditions. In conclusion, these findings indicate a novel feed-forward loop and suggest that ARNT might be a limiting factor. Augmented HIF signalling in terms of elevated target gene expression might be advantageous for tumour cells.
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12
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Lee SC, Min HY, Choi H, Bae SY, Park KH, Hyun SY, Lee HJ, Moon J, Park SH, Kim JY, An H, Park SJ, Seo JH, Lee S, Kim YM, Park HJ, Lee SK, Lee J, Lee J, Kim KW, Suh YG, Lee HY. Deguelin Analogue SH-1242 Inhibits Hsp90 Activity and Exerts Potent Anticancer Efficacy with Limited Neurotoxicity. Cancer Res 2015; 76:686-99. [DOI: 10.1158/0008-5472.can-15-1492] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 10/23/2015] [Indexed: 11/16/2022]
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13
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Mandl M, Lieberum MK, Dunst J, Depping R. The expression level of the transcription factor Aryl hydrocarbon receptor nuclear translocator (ARNT) determines cellular survival after radiation treatment. Radiat Oncol 2015; 10:229. [PMID: 26572229 PMCID: PMC4647475 DOI: 10.1186/s13014-015-0539-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 11/10/2015] [Indexed: 12/14/2022] Open
Abstract
Background Tumour hypoxia promotes radioresistance and is associated with poor prognosis. The transcription factor Aryl hydrocarbon receptor nuclear translocator (ARNT), also designated as Hypoxia-inducible factor (HIF)-1β, is part of the HIF pathway which mediates cellular adaptations to oxygen deprivation and facilitates tumour progression. The subunits HIF-1α and ARNT are key players within this pathway. HIF-1α is regulated in an oxygen-dependent manner whereas ARNT is considered to be constitutively expressed. However, there is mounting evidence that certain tumour cells are capable to elevate ARNT in hypoxia which suggests a survival benefit. Therefore the objective of this study was to elucidate effects of an altered ARNT expression level on the cellular response to radiation. Methods Different human cell lines (Hep3B, MCF-7, 786-Owt, 786-Ovhl, RCC4wt and RCC4vhl) originating from various tumour entities (Hepatocellular carcinoma, breast cancer and renal cell carcinoma respectively) were X-irradiated using a conventional linear accelerator. Knockdown of ARNT expression was achieved by transient siRNA transfection. Complementary experiments were performed by forced ARNT overexpression using appropriate plasmids. Presence/absence of ARNT protein was confirmed by Western blot analysis. Clonogenic survival assays were performed in order to determine cellular survival post irradiation. Statistical comparison of two groups was achieved by the unpaired t-test. Results The results of this study indicate that ARNT depletion renders tumour cells susceptible to radiation whereas overexpression of this transcription factor confers radioresistance. Conclusions These findings provide evidence to consider ARNT as a drug target and as a predictive marker in clinical applications concerning the response to radiation. Electronic supplementary material The online version of this article (doi:10.1186/s13014-015-0539-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Markus Mandl
- Institute of Physiology, Center for Structural and Cell Biology in Medicine, University of Luebeck, Ratzeburger Allee 160, 23562, Luebeck, Germany.
| | - Maria- Katharina Lieberum
- Institute of Physiology, Center for Structural and Cell Biology in Medicine, University of Luebeck, Ratzeburger Allee 160, 23562, Luebeck, Germany. .,Klinik für Strahlentherapie, Universitaetsklinikum Schleswig-Holstein, Campus Luebeck, Ratzeburger Allee 160, 23538, Luebeck, Germany.
| | - Juergen Dunst
- Klinik für Strahlentherapie, Universitaetsklinikum Schleswig-Holstein, Campus Luebeck, Ratzeburger Allee 160, 23538, Luebeck, Germany.
| | - Reinhard Depping
- Institute of Physiology, Center for Structural and Cell Biology in Medicine, University of Luebeck, Ratzeburger Allee 160, 23562, Luebeck, Germany.
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Vartholomaiou E, Echeverría PC, Picard D. Unusual Suspects in the Twilight Zone Between the Hsp90 Interactome and Carcinogenesis. Adv Cancer Res 2015; 129:1-30. [PMID: 26915999 DOI: 10.1016/bs.acr.2015.08.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The molecular chaperone Hsp90 has attracted a lot of interest in cancer research ever since cancer cells were found to be more sensitive to Hsp90 inhibition than normal cells. Why that is has remained a matter of debate and is still unclear. In addition to increased Hsp90 dependence for some mutant cancer proteins and modifications of the Hsp90 machinery itself, a number of other characteristics of cancer cells probably contribute to this phenomenon; these include aneuploidy and overall increased numbers and levels of defective and mutant proteins, which all contribute to perturbed proteostasis. Work over the last two decades has demonstrated that many cancer-related proteins are Hsp90 clients, and yet only few of them have been extensively investigated, selected either on the basis of their obvious function as cancer drivers or because they proved to be convenient biomarkers for monitoring the effects of Hsp90 inhibitors. The purpose of our review is to go beyond these "usual suspects." We established a workflow to select poorly studied proteins that are related to cancer processes and qualify as Hsp90 clients. By discussing and taking a fresh look at these "unusual suspects," we hope to stimulate others to revisit them as novel therapeutic targets or diagnostic markers.
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Affiliation(s)
| | - Pablo C Echeverría
- Département de Biologie Cellulaire, Université de Genève, Sciences III, Geneva, Switzerland
| | - Didier Picard
- Département de Biologie Cellulaire, Université de Genève, Sciences III, Geneva, Switzerland.
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15
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Zhao G, Liu Y, Fang J, Chen Y, Li H, Gao K. Dimethyl fumarate inhibits the expression and function of hypoxia-inducible factor-1α (HIF-1α). Biochem Biophys Res Commun 2014; 448:303-7. [DOI: 10.1016/j.bbrc.2014.02.062] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 02/14/2014] [Indexed: 01/23/2023]
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16
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Zhu J, Jiang X, Chehab FF. FoxO4 interacts with the sterol regulatory factor SREBP2 and the hypoxia inducible factor HIF2α at the CYP51 promoter. J Lipid Res 2013; 55:431-42. [PMID: 24353279 DOI: 10.1194/jlr.m043521] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The late steps of cholesterol biosynthesis are oxygen demanding, requiring eleven oxygen molecules per synthesized cholesterol molecule. A key enzymatic reaction, which occurs at the top of the Bloch and Kandutsch-Russell pathways, is the demethylation of lanosterol and dihydrolanosterol (DHL). This reaction is catalyzed by lanosterol 14α demethylase (CYP51) and requires three oxygen molecules. Thus, it is the first step in the distal pathway to be susceptible to oxygen deprivation. Having previously identified that the forkhead transcription factor 4 (FoxO4) represses CYP51 expression, we aimed to characterize its role at the CYP51 promoter. Hypoxia-treated 3T3L1 cells showed decreased cholesterol biosynthesis, accumulation of lanosterol/DHL, and stimulation of FoxO4 expression and its cytoplasmic translocation to the nucleus. Transfection assays with a CYP51 promoter reporter gene revealed that FoxO4 and sterol regulatory element binding protein (SREBP)2 exert a stimulatory effect, whereas FoxO4 and the hypoxia inducible factor (HIF)2α repress CYP51 promoter activity. Electromobility shift, chromatin immunoprecipitation, pull-down, and coimmunoprecipitation assays show that FoxO4 interacts with SREBP2 and HIF2α to modulate CYP51 promoter activity. We also show an inverse correlation between FoxO4 and CYP51 in adipose tissue of ob/ob mice and mouse fetal cortical neurons exposed to hypoxia. Overall, these studies demonstrate a role for FoxO4 in the regulation of CYP51 expression.
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Affiliation(s)
- Jun Zhu
- Departments of Laboratory Medicine University of California, San Francisco, CA 94143
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Xiang L, Gilkes DM, Chaturvedi P, Luo W, Hu H, Takano N, Liang H, Semenza GL. Ganetespib blocks HIF-1 activity and inhibits tumor growth, vascularization, stem cell maintenance, invasion, and metastasis in orthotopic mouse models of triple-negative breast cancer. J Mol Med (Berl) 2013; 92:151-64. [PMID: 24248265 DOI: 10.1007/s00109-013-1102-5] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 11/04/2013] [Accepted: 11/06/2013] [Indexed: 01/01/2023]
Abstract
UNLABELLED Targeted therapy against triple-negative breast cancers, which lack expression of the estrogen, progesterone, and HER2 receptors, is not available and the overall response to cytotoxic chemotherapy is poor. One of the molecular hallmarks of triple-negative breast cancers is increased expression of genes that are transcriptionally activated by hypoxia-inducible factors (HIFs), which are implicated in many critical aspects of cancer progression including metabolism, angiogenesis, invasion, metastasis, and stem cell maintenance. Ganetespib is a second-generation inhibitor of heat shock protein 90 (HSP90), a molecular chaperone that is essential for the stability and function of multiple client proteins in cancer cells including HIF-1α. In this study, human MDA-MB-231 and MDA-MB-435 triple-negative breast cancer cells were injected into the mammary fat pad of immunodeficient mice that received weekly intravenous injections of ganetespib or vehicle following the development of palpable tumors. Ganetespib treatment markedly impaired primary tumor growth and vascularization, and eliminated local tissue invasion and distant metastasis to regional lymph nodes and lungs. Ganetespib treatment also significantly reduced the number of Aldefluor-positive cancer stem cells in the primary tumor. Primary tumors of ganetespib-treated mice had significantly reduced levels of HIF-1α (but not HIF-2α) protein and of HIF-1 target gene mRNAs encoding proteins that play key roles in angiogenesis, metabolism, invasion, and metastasis, thereby providing a molecular basis for observed effects of the drug on the growth and metastasis of triple-negative breast cancer. KEY MESSAGES Triple-negative breast cancers (TNBCs) respond poorly to available chemotherapy. TNBCs overexpress genes regulated by hypoxia-inducible factors (HIFs). Ganetespib induces degradation of HSP90 client proteins, including HIF-1α. Ganetespib inhibited TNBC orthotopic tumor growth, invasion, and metastasis. Ganetespib inhibited expression of HIF-1 target genes involved in TNBC progression.
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Affiliation(s)
- Lisha Xiang
- Vascular Program, Institute for Cell Engineering, Baltimore, MD, 21205, USA
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18
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Lyberopoulou A, Mylonis I, Papachristos G, Sagris D, Kalousi A, Befani C, Liakos P, Simos G, Georgatsou E. MgcRacGAP, a cytoskeleton regulator, inhibits HIF-1 transcriptional activity by blocking its dimerization. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:1378-87. [PMID: 23458834 DOI: 10.1016/j.bbamcr.2013.02.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 02/19/2013] [Accepted: 02/21/2013] [Indexed: 01/22/2023]
Abstract
Hypoxia inducible factor-1 (HIF-1), a dimeric transcription factor of the bHLH-PAS family, is comprised of HIF-1α, which is inducible by hypoxia and ARNT or HIF-1β, which is constitutively expressed. HIF-1 is involved in cellular homeostasis under hypoxia, in development and in several diseases affected by oxygen availability, particularly cancer. Since its expression is positively correlated with poor outcome prognosis for cancer patients, HIF-1 is a target for pharmaceutical therapy. We have previously shown that male germ cell Rac GTPase activating protein (MgcRacGAP), a regulator of Rho proteins which are principally involved in cytoskeletal organization, binds to HIF-1α and inhibits its transcriptional activity. In this work, we have explored the mechanism of the MgcRacGAP-mediated HIF-1 inactivation. We show that the Myo domain of MgcRacGAP, which is both necessary and sufficient for HIF-1 repression, binds to the PAS-B domain of HIF-1α. Furthermore MgcRacGAP competes with ARNT for binding to the HIF-1α PAS-B domain, as shown by in vitro binding pull down assays. In mammalian cells, ARNT overexpression can overcome the MgcRacGAP-mediated inhibition and MgcRacGAP binding to HIF-1α in vivo inhibits its dimerization with ARNT. We additionally present results indicating that MgcRacGAP binding to HIF-1α is specific, since it does not affect the transcriptional activity of HIF-2, a close evolutionary relative of HIF-1 also involved in hypoxia regulation and cancer. Our results reveal a new mechanism for HIF-1 transcriptional activity regulation, suggest a novel hypoxia-cytoskeleton link and provide new tools for selective HIF-1 inhibition.
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Prabhakar NR, Semenza GL. Adaptive and maladaptive cardiorespiratory responses to continuous and intermittent hypoxia mediated by hypoxia-inducible factors 1 and 2. Physiol Rev 2012; 92:967-1003. [PMID: 22811423 DOI: 10.1152/physrev.00030.2011] [Citation(s) in RCA: 429] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Hypoxia is a fundamental stimulus that impacts cells, tissues, organs, and physiological systems. The discovery of hypoxia-inducible factor-1 (HIF-1) and subsequent identification of other members of the HIF family of transcriptional activators has provided insight into the molecular underpinnings of oxygen homeostasis. This review focuses on the mechanisms of HIF activation and their roles in physiological and pathophysiological responses to hypoxia, with an emphasis on the cardiorespiratory systems. HIFs are heterodimers comprised of an O(2)-regulated HIF-1α or HIF-2α subunit and a constitutively expressed HIF-1β subunit. Induction of HIF activity under conditions of reduced O(2) availability requires stabilization of HIF-1α and HIF-2α due to reduced prolyl hydroxylation, dimerization with HIF-1β, and interaction with coactivators due to decreased asparaginyl hydroxylation. Stimuli other than hypoxia, such as nitric oxide and reactive oxygen species, can also activate HIFs. HIF-1 and HIF-2 are essential for acute O(2) sensing by the carotid body, and their coordinated transcriptional activation is critical for physiological adaptations to chronic hypoxia including erythropoiesis, vascularization, metabolic reprogramming, and ventilatory acclimatization. In contrast, intermittent hypoxia, which occurs in association with sleep-disordered breathing, results in an imbalance between HIF-1α and HIF-2α that causes oxidative stress, leading to cardiorespiratory pathology.
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Affiliation(s)
- Nanduri R Prabhakar
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, Biological Sciences Division, University of Chicago, Chicago, Illinois, USA.
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20
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Bohonowych JES, Peng S, Gopal U, Hance MW, Wing SB, Argraves KM, Lundgren K, Isaacs JS. Comparative analysis of novel and conventional Hsp90 inhibitors on HIF activity and angiogenic potential in clear cell renal cell carcinoma: implications for clinical evaluation. BMC Cancer 2011; 11:520. [PMID: 22172030 PMCID: PMC3259130 DOI: 10.1186/1471-2407-11-520] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Accepted: 12/15/2011] [Indexed: 02/21/2023] Open
Abstract
BACKGROUND Perturbing Hsp90 chaperone function targets hypoxia inducible factor (HIF) function in a von Hippel-Lindau (VHL) independent manner, and represents an approach to combat the contribution of HIF to cell renal carcinoma (CCRCC) progression. However, clinical trials with the prototypic Hsp90 inhibitor 17-AAG have been unsuccessful in halting the progression of advanced CCRCC. METHODS Here we evaluated a novel next generation small molecule Hsp90 inhibitor, EC154, against HIF isoforms and HIF-driven molecular and functional endpoints. The effects of EC154 were compared to those of the prototypic Hsp90 inhibitor 17-AAG and the histone deacetylase (HDAC) inhibitor LBH589. RESULTS The findings indicate that EC154 is a potent inhibitor of HIF, effective at doses 10-fold lower than 17-AAG. While EC154, 17-AAG and the histone deacetylase (HDAC) inhibitor LBH589 impaired HIF transcriptional activity, CCRCC cell motility, and angiogenesis; these effects did not correlate with their ability to diminish HIF protein expression. Further, our results illustrate the complexity of HIF targeting, in that although these agents suppressed HIF transcripts with differential dynamics, these effects were not predictive of drug efficacy in other relevant assays. CONCLUSIONS We provide evidence for EC154 targeting of HIF in CCRCC and for LBH589 acting as a suppressor of both HIF-1 and HIF-2 activity. We also demonstrate that 17-AAG and EC154, but not LBH589, can restore endothelial barrier function, highlighting a potentially new clinical application for Hsp90 inhibitors. Finally, given the discordance between HIF activity and protein expression, we conclude that HIF expression is not a reliable surrogate for HIF activity. Taken together, our findings emphasize the need to incorporate an integrated approach in evaluating Hsp90 inhibitors within the context of HIF suppression.
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Affiliation(s)
- Jessica E S Bohonowych
- Department of Cell and Molecular Pharmacology, Medical University of South Carolina, Charleston, SC, USA
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21
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Mechanisms of Resistance to Hsp90 Inhibitor Drugs: A Complex Mosaic Emerges. Pharmaceuticals (Basel) 2011; 4:1400-1422. [PMID: 27721330 PMCID: PMC4060131 DOI: 10.3390/ph4111400] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 10/04/2011] [Accepted: 10/17/2011] [Indexed: 01/07/2023] Open
Abstract
The molecular chaperone Hsp90 holds great promise as a cancer drug target, despite some of the initial clinical trials of Hsp90 inhibitor drugs having not lived up to expectation. Effective use of these drugs will benefit greatly from a much more detailed understanding of the factors that contribute to resistance, whether intrinsic or acquired. We review how cell culture studies have revealed a number of different mechanisms whereby cells can be rendered less susceptible to the effects of Hsp90 inhibitor treatment. A major influence is Hsp90 inhibition causing strong induction of the heat shock response, a stress response that increases cellular levels of prosurvival chaperones such as Hsp27 and Hsp70. Another problem seems to be that these inhibitors do not always access the Hsp90 proteins of the mitochondrion, forms of Hsp90 that—in cancer cells—are operating to suppress apoptosis. It should be possible to overcome these drawbacks through the appropriate drug redesign or with the combinatorial use of an Hsp90 inhibitor with a drug that targets either heat shock factor or the chaperone Hsp70. Still though, cells will often differ in the key antiapoptotic versus proapoptotic activities that are dependent on Hsp90, in the key steps in their apoptotic pathways responsive to Hsp90 inhibition or Hsp70 level, as well as the extents to which their survival is dependent on oncogenic tyrosine kinases that are clients of Hsp90. A systems approach will therefore often be required in order to establish the most prominent effects of Hsp90 inhibition in each type of cancer cell.
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Niu X, Zhang T, Liao L, Zhou L, Lindner DJ, Zhou M, Rini B, Yan Q, Yang H. The von Hippel-Lindau tumor suppressor protein regulates gene expression and tumor growth through histone demethylase JARID1C. Oncogene 2011; 31:776-86. [PMID: 21725364 DOI: 10.1038/onc.2011.266] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In clear-cell renal cell carcinoma (ccRCC), inactivation of the tumor suppressor von Hippel-Lindau (VHL) occurs in the majority of the tumors and is causal for the pathogenesis of ccRCC. Recently, a large-scale genomic sequencing study of ccRCC tumors revealed that enzymes that regulate histone H3 lysine 4 trimethylation (H3K4Me3), such as JARID1C/KDM5C/SMCX and MLL2, were mutated in ccRCC tumors, suggesting that H3K4Me3 might have an important role in regulating gene expression and tumorigenesis. In this study we report that in VHL-deficient ccRCC cells, the overall H3K4Me3 levels were significantly lower than that of VHL+/+ counterparts. Furthermore, this was hypoxia-inducible factor (HIF) dependent, as depletion of HIF subunits by small hairpin RNA in VHL-deficient ccRCC cells restored H3K4Me3 levels. In addition, we demonstrated that only loss of JARID1C, not JARID1A or JARID1B, abolished the difference of H3K4Me3 levels between VHL-/- and VHL+/+ cells, and JARID1C displayed HIF-dependent expression pattern. JARID1C in VHL-/- cells was responsible for the suppression of HIF-responsive genes insulin-like growth factor-binding protein 3 (IGFBP3), DNAJC12, COL6A1, growth and differentiation factor 15 (GDF15) and density-enhanced phosphatase 1. Consistent with these findings, the H3K4Me3 levels at the promoters of IGFBP3, DNAJC12, COL6A1 and GDF15 were lower in VHL-/- cells than in VHL+/+ cells, and the differences disappeared after JARID1C depletion. Although HIF2α is an oncogene in ccRCC, some of its targets might have tumor suppressive activity. Consistent with this, knockdown of JARID1C in 786-O VHL-/- ccRCC cells significantly enhanced tumor growth in a xenograft model, suggesting that JARID1C is tumor suppressive and its mutations are tumor promoting in ccRCC. Thus, VHL inactivation decreases H3K4Me3 levels through JARID1C, which alters gene expression and suppresses tumor growth.
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Affiliation(s)
- X Niu
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
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23
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Efroni S, Ben-Hamo R, Edmonson M, Greenblum S, Schaefer CF, Buetow KH. Detecting cancer gene networks characterized by recurrent genomic alterations in a population. PLoS One 2011; 6:e14437. [PMID: 21283511 PMCID: PMC3014942 DOI: 10.1371/journal.pone.0014437] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Accepted: 10/08/2010] [Indexed: 11/19/2022] Open
Abstract
High resolution, system-wide characterizations have demonstrated the capacity to identify genomic regions that undergo genomic aberrations. Such research efforts often aim at associating these regions with disease etiology and outcome. Identifying the corresponding biologic processes that are responsible for disease and its outcome remains challenging. Using novel analytic methods that utilize the structure of biologic networks, we are able to identify the specific networks that are highly significantly, nonrandomly altered by regions of copy number amplification observed in a systems-wide analysis. We demonstrate this method in breast cancer, where the state of a subset of the pathways identified through these regions is shown to be highly associated with disease survival and recurrence.
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Affiliation(s)
- Sol Efroni
- The Mina & Everard Faculty of Life Science, Bar Ilan University, Ramat Gan, Israel
| | - Rotem Ben-Hamo
- The Mina & Everard Faculty of Life Science, Bar Ilan University, Ramat Gan, Israel
| | - Michael Edmonson
- Laboratory of Population Genetics, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sharon Greenblum
- Laboratory of Population Genetics, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Carl F. Schaefer
- National Cancer Institute Center for Biomedical Informatics and Information Technology, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Kenneth H. Buetow
- Laboratory of Population Genetics, National Institutes of Health, Bethesda, Maryland, United States of America
- National Cancer Institute Center for Biomedical Informatics and Information Technology, National Institutes of Health, Bethesda, Maryland, United States of America
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The metabolic switch and its regulation in cancer cells. SCIENCE CHINA-LIFE SCIENCES 2010; 53:942-58. [PMID: 20821293 DOI: 10.1007/s11427-010-4041-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Accepted: 05/07/2010] [Indexed: 02/05/2023]
Abstract
The primary features of cancer are maintained via intrinsically modified metabolic activity, which is characterized by enhanced nutrient supply, energy production, and biosynthetic activity to synthesize a variety of macromolecular components during each passage through the cell cycle. This metabolic shift in transformed cells, as compared with non-proliferating cells, involves aberrant activation of aerobic glycolysis, de novo lipid biosynthesis and glutamine-dependent anaplerosis to fuel robust cell growth and proliferation. Here, we discuss the unique metabolic characteristics of cancer, the constitutive regulation of metabolism through a variety of signal transduction pathways and/or enzymes involved in metabolic reprogramming in cancer cells, and their implications in cancer diagnosis and therapy.
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Kong HS, Lee S, Beebe K, Scroggins B, Gupta G, Lee MJ, Jung YJ, Trepel J, Neckers L. Emetine promotes von Hippel-Lindau-independent degradation of hypoxia-inducible factor-2α in clear cell renal carcinoma. Mol Pharmacol 2010; 78:1072-8. [PMID: 20813864 DOI: 10.1124/mol.110.066514] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Inactivating mutations of the von Hippel-Lindau (VHL) tumor suppressor gene are associated with inherited VHL syndrome, which is characterized by susceptibility to a variety of neoplasms, including central nervous system hemangioblastoma and clear cell renal cell carcinoma (CCRCC). Mutations in the VHL gene are also found in the majority of sporadic clear cell renal carcinoma, the most common malignant neoplasm of the human kidney. Inactivation of VHL ubiquitin ligase is associated with normoxic stabilization of hypoxia-inducible factor-1α and 2-α (HIF-1α and HIF-2α), transcriptional regulators of tumor angiogenesis, invasion, survival, and glucose utilization. HIF-2α has been particularly implicated in the development of CCRCC. Although several inhibitors of HIF-1α have been described, these drugs typically have a minimal affect on HIF-2α. 786-O is a VHL-deficient CCRCC cell line that constitutively expresses only HIF-2α and is therefore suitable for the screening of novel HIF-2α inhibitors. Using this cell line, we have identified emetine as a specific inhibitor of HIF-2α protein stability and transcriptional activity. Without altering HIF-2α mRNA level, emetine rapidly and dramatically down-regulated HIF-2α protein expression in 786-O cells. HIF-2α down-regulation was accompanied by HIF-2α ubiquitination and was reversed by proteasome inhibition. Emetine-induced HIF-2α down-regulation was confirmed in three additional VHL-renal cancer cell lines, was insensitive to the prolyl hydroxylase inhibitor dimethyloxaloyl glycine, and did not require neural precursor cell expressed developmentally down-regulated-8, suggesting that emetine accesses a previously undescribed cullin-independent proteasome degradation pathway for HIF-2α. These data support the use of emetine or structurally related compounds as useful leads for the identification of novel HIF-2α inhibitors.
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Affiliation(s)
- Hye-Sik Kong
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
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Kalousi A, Mylonis I, Politou AS, Chachami G, Paraskeva E, Simos G. Casein kinase 1 regulates human hypoxia-inducible factor HIF-1. J Cell Sci 2010; 123:2976-86. [PMID: 20699359 DOI: 10.1242/jcs.068122] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hypoxia-inducible factor 1 (HIF-1), a transcriptional activator that mediates cellular response to hypoxia and a promising target of anticancer therapy, is essential for adaptation to low oxygen conditions, embryogenesis and tumor progression. HIF-1 is a heterodimer of HIF-1alpha, expression of which is controlled by oxygen levels as well as by various oxygen-independent mechanisms, and HIF-1beta (or ARNT), which is constitutively expressed. In this work, we investigate the phosphorylation of the N-terminal heterodimerization (PAS) domain of HIF-1alpha and identify Ser247 as a major site of in vitro modification by casein kinase 1delta (CK1delta). Mutation of this site to alanine, surprisingly, enhanced the transcriptional activity of HIF-1alpha, a result phenocopied by inhibition or small interfering RNA (siRNA)-mediated silencing of CK1delta under hypoxic conditions. Conversely, overexpression of CK1delta or phosphomimetic mutation of Ser247 to aspartate inhibited HIF-1alpha activity without affecting its stability or nuclear accumulation. Immunoprecipitation and in vitro binding experiments suggest that CK1-dependent phosphorylation of HIF-1alpha at Ser247 impairs its association with ARNT, a notion also supported by modeling the structure of the complex between HIF-1alpha and ARNT PAS-B domains. We suggest that modification of HIF-1alpha by CK1 represents a novel mechanism that controls the activity of HIF-1 during hypoxia by regulating the interaction between its two subunits.
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Affiliation(s)
- Alkmini Kalousi
- Laboratory of Biochemistry, School of Medicine, University of Thessaly, Mezourlo 41110, Larissa, Greece
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Zhang L, Ma J, Li Y, Guo L, Ran Y, Liu S, Jiang C, Zhu D. 15-Hydroxyeicosatetraenoic acid (15-HETE) protects pulmonary artery smooth muscle cells against apoptosis via HSP90. Life Sci 2010; 87:223-31. [DOI: 10.1016/j.lfs.2010.06.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 05/20/2010] [Accepted: 06/14/2010] [Indexed: 01/11/2023]
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Hsp90 as a gatekeeper of tumor angiogenesis: clinical promise and potential pitfalls. JOURNAL OF ONCOLOGY 2010; 2010:412985. [PMID: 20628489 PMCID: PMC2902748 DOI: 10.1155/2010/412985] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2009] [Accepted: 04/12/2010] [Indexed: 01/05/2023]
Abstract
Tumor vascularization is an essential modulator of early tumor growth, progression, and therapeutic outcome. Although antiangiogenic treatments appear promising, intrinsic and acquired tumor resistance contributes to treatment failure. Clinical inhibition of the molecular chaperone heat shock protein 90 (Hsp90) provides an opportunity to target multiple aspects of this signaling resiliency, which may elicit more robust and enduring tumor repression relative to effects elicited by specifically targeted agents. This review highlights several primary effectors of angiogenesis modulated by Hsp90 and describes the clinical challenges posed by the redundant circuitry of these pathways. The four main topics addressed include (1) Hsp90-mediated regulation of HIF/VEGF signaling, (2) chaperone-dependent regulation of HIF-independent VEGF-mediated angiogenesis, (3) Hsp90-dependent targeting of key proangiogenic receptor tyrosine kinases and modulation of drug resistance, and (4) consideration of factors such as tumor microenvironment that pose several challenges for the clinical efficacy of anti-angiogenic therapy and Hsp90-targeted strategies.
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Regulation of Hsp90 client proteins by a Cullin5-RING E3 ubiquitin ligase. Proc Natl Acad Sci U S A 2009; 106:20330-5. [PMID: 19933325 DOI: 10.1073/pnas.0810571106] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
We report a link between Cullin5 (Cul5) E3 ubiquitin ligase and the heat shock protein 90 (Hsp90) chaperone complex. Hsp90 participates in the folding of its client proteins into their functional conformation. Many Hsp90 clients have been reported to be aberrantly expressed in a number of cancers. We demonstrate Cul5 interaction with members of the Hsp90 chaperone complex as well as the Hsp90 client, ErbB2. We observed recruitment of Cul5 to the site of ErbB2 at the plasma membrane and subsequent induction of polyubiquitination and proteasomal degradation. We also demonstrate Cul5 involvement in regulation of another Hsp90 client, Hif-1alpha. We observed Cul5 degradation of ErbB2 to occur independently of ElonginB-ElonginC function. The involvement of Cul5 in Hsp90 client regulation has implications in the effectiveness of Hsp90 targeted chemotherapy, which is currently undergoing clinical trials. The link between Cul5 and Hsp90 client regulation may represent an avenue for cancer drug development.
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Ugocsai P, Hohenstatt A, Paragh G, Liebisch G, Langmann T, Wolf Z, Weiss T, Groitl P, Dobner T, Kasprzak P, Göbölös L, Falkert A, Seelbach-Goebel B, Gellhaus A, Winterhager E, Schmidt M, Semenza GL, Schmitz G. HIF-1beta determines ABCA1 expression under hypoxia in human macrophages. Int J Biochem Cell Biol 2009; 42:241-52. [PMID: 19828131 DOI: 10.1016/j.biocel.2009.10.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Revised: 09/29/2009] [Accepted: 10/05/2009] [Indexed: 11/19/2022]
Abstract
ATP-binding cassette transporter A1 plays (ABCA1) a major role in reverse cholesterol transport, a process closely related to atherogenesis. In the thickening atherosclerotic lesions lipid loaded macrophages are exposed to regions of local hypoxia that may influence reverse cholesterol transport. Here we studied the effect of hypoxia on ABCA1 regulation and cholesterol efflux in human macrophages. We found that the hypoxia-inducible factor 1 (HIF-1) specifically binds to the HIF-1 response element of the ABCA1 promoter and the HIF-1 complex increases ABCA1 promoter activity along with ABCA1 expression. Primary human macrophages exposed to hypoxia or expressing constitutively active HIF-1alpha responded with a potent change in ABCA1 expression, which showed a strong correlation with HIF-1beta expression (r: 0.95-0.91). Moreover, ABCA1-mediated cholesterol efflux was also found to be regulated by HIF-1beta under hypoxia. In vivo, in macrophages prepared from human atherosclerotic lesions ABCA1 levels showed a strong correlation with HIF-1beta expression. This in vivo regulatory mechanism was confirmed in human pre-eclamptic placentas, a clinical condition with severe local hypoxia. These results demonstrate that HIF-1beta availability determines ABCA1 expression and cholesterol efflux in macrophages under hypoxia and may contribute to the interpersonal variability of atherosclerotic lesion progression.
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Affiliation(s)
- Peter Ugocsai
- Institute for Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, Regensburg, Germany
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Tsutsumi S, Beebe K, Neckers L. Impact of heat-shock protein 90 on cancer metastasis. Future Oncol 2009; 5:679-88. [PMID: 19519207 DOI: 10.2217/fon.09.30] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Cancer metastasis is the result of complex processes, including alteration of cell adhesion/motility in the microenvironment and neoangiogenesis, that are necessary to support cancer growth in tissues distant from the primary tumor. The molecular chaperone heat-shock protein 90 (Hsp90), also termed the 'cancer chaperone', plays a crucial role in maintaining the stability and activity of numerous signaling proteins involved in these processes. Small-molecule Hsp90 inhibitors display anticancer activity both in vitro and in vivo, and multiple Phase II and Phase III clinical trials of several structurally distinct Hsp90 inhibitors are currently underway. In this review, we will highlight the importance of Hsp90 in cancer metastasis and the therapeutic potential of Hsp90 inhibitors as antimetastasis drugs.
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Affiliation(s)
- Shinji Tsutsumi
- Urologic Oncology Branch, National Cancer Institute, NIH, Bethesda, MD 20892-1107, USA
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Clinical implications of hypoxia inducible factor in renal cell carcinoma. Urol Oncol 2009; 27:238-45. [PMID: 19414111 DOI: 10.1016/j.urolonc.2007.12.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2007] [Accepted: 12/07/2007] [Indexed: 01/25/2023]
Abstract
Management of renal cell carcinoma (RCC) has made considerable strides in the past decade, due in large part to identification of the von Hippel Lindau (VHL) tumor suppressor as a negative regulator of hypoxia inducible factor alpha (HIF-alpha) protein expression. Stabilization of HIF-alpha appears to be critical for renal tumorigenesis, and is observed even in VHL-independent RCC. Thus, an understanding of the pathways that regulate expression and activation of the different HIF-alpha isoforms is key to delineating the mechanism of renal transformation and for the development of novel therapeutics. A number of agents targeting HIF-alpha or its transcriptionally-regulated genes have shown promise in treatment of RCC. However, more effective treatment strategies are still needed. This report provides a directed review of recent discoveries defining the role of HIF in renal tumorigenesis and their relevance to the clinical advances in targeted therapy for advanced RCC.
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Kawanami D, Mahabeleshwar GH, Lin Z, Atkins GB, Hamik A, Haldar SM, Maemura K, Lamanna JC, Jain MK. Kruppel-like factor 2 inhibits hypoxia-inducible factor 1alpha expression and function in the endothelium. J Biol Chem 2009; 284:20522-30. [PMID: 19491109 DOI: 10.1074/jbc.m109.025346] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Hypoxia-inducible factor 1 (HIF-1) is a central regulator of the hypoxic response in many cell types. In endothelial cells, HIF-1 induces the expression of key proangiogenic factors to promote angiogenesis. Recent studies have identified Kruppel-like factor 2 (KLF2) as a potent inhibitor of angiogenesis. However, the role of KLF2 in regulating HIF-1 expression and function has not been evaluated. KLF2 expression was induced acutely by hypoxia in endothelial cells. Adenoviral overexpression of KLF2 inhibited hypoxia-induced expression of HIF-1alpha and its target genes such as interleukin 8, angiopoietin-2, and vascular endothelial growth factor in endothelial cells. Conversely, knockdown of KLF2 increased expression of HIF-1alpha and its targets. Furthermore, KLF2 inhibited hypoxia-induced endothelial tube formation, whereas endothelial cells from mice with haploinsufficiency of KLF2 showed increased tube formation in response to hypoxia. Consistent with this ex vivo observation, KLF2 heterozygous mice showed increased microvessel density in the brain. Mechanistically, KLF2 promoted HIF-1alpha degradation in a von Hippel-Lindau protein-independent but proteasome-dependent manner. Finally, KLF2 disrupted the interaction between HIF-1alpha and its chaperone Hsp90, suggesting that KLF2 promotes degradation of HIF-1alpha by affecting its folding and maturation. These observations identify KLF2 as a novel inhibitor of HIF-1alpha expression and function. Therefore, KLF2 may be a target for modulating the angiogenic response in disease states.
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Affiliation(s)
- Daiji Kawanami
- University Hospitals Harrington-McLaughlin Heart & Vascular Institute and Case Cardiovascular Research Institute, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
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Li F, Luan W, Zhang C, Zhang J, Wang B, Xie Y, Li S, Xiang J. Cloning of cytoplasmic heat shock protein 90 (FcHSP90) from Fenneropenaeus chinensis and its expression response to heat shock and hypoxia. Cell Stress Chaperones 2009; 14:161-72. [PMID: 18668349 PMCID: PMC2727990 DOI: 10.1007/s12192-008-0069-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2008] [Revised: 05/28/2008] [Accepted: 07/14/2008] [Indexed: 10/21/2022] Open
Abstract
Heat shock protein 90 (HSP90) works as a multi-functional chaperone and is involved in the regulation of many essential cellular pathways. In this study, we have identified a full-length complementary DNA (cDNA) of HSP90 (FcHSP90) from Chinese shrimp Fenneropenaeus chinensis. FcHSP90 full-length cDNA comprised 2,552 bp, including a 2,181-bp open reading frame encoding 726 amino acids. Both homology analyses using alignment with previously identified HSP90 and a phylogeny tree indicated that FcHSP90 was a cytoplasmic HSP90. Real-time reverse transcription polymerase chain reaction analysis revealed that FcHSP90 was ubiquitously expressed in all the examined tissues but with highest levels in ovary of F. chinensis. FcHSP90 mRNA levels were sensitively induced by heat shock (from 25 degrees C to 35 degrees C) and reached the maximum at 6 h during heat shock treatment. Under hypoxia conditions, FcHSP90 mRNA levels, in both hemocytes and gill, were induced at 2 h and depressed at 8 h during hypoxia stress. The assessment of FcHSP90 mRNA levels under heat shock and hypoxia stresses indicated that the transcription of FcHSP90 was very sensitive to heat shock and hypoxia, so we deduced that FcHSP90 might play very important roles for shrimp to cope with environmental stress.
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Affiliation(s)
- Fuhua Li
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071 China
| | - Wei Luan
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071 China
- Graduate School, Chinese Academy of Sciences, Beijing, 100039 China
| | - Chengsong Zhang
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071 China
- Graduate School, Chinese Academy of Sciences, Beijing, 100039 China
| | - Jiquan Zhang
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071 China
| | - Bing Wang
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071 China
| | - Yusu Xie
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071 China
- Graduate School, Chinese Academy of Sciences, Beijing, 100039 China
| | - Shihao Li
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071 China
- Graduate School, Chinese Academy of Sciences, Beijing, 100039 China
| | - Jianhai Xiang
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071 China
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Amir S, Wang R, Simons JW, Mabjeesh NJ. SEPT9_v1 up-regulates hypoxia-inducible factor 1 by preventing its RACK1-mediated degradation. J Biol Chem 2009; 284:11142-51. [PMID: 19251694 DOI: 10.1074/jbc.m808348200] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A critical mediator of the cellular response to hypoxia is hypoxia-inducible factor 1 (HIF-1). Increased levels of HIF-1alpha are often associated with increased tumor metastasis, therapeutic resistance, and poorer prognosis. We recently identified a novel interaction between HIF-1alpha and the mammalian septin family member, SEPT9_v1. Septins are a highly conserved family of GTP-binding cytoskeletal proteins that are implicated in multiple cellular functions, including cell division and oncogenesis. SEPT9_v1 binds and stabilizes HIF-1alpha protein and stimulates HIF-1 transcriptional activity. SEPT9_v1-HIF-1 activation promotes tumor growth and angiogenesis. The structural and functional relationships between SEPT9_v1 and HIF-1alpha were analyzed. We found that SEPT9_v1 binds specifically with HIF-1alpha but not with HIF-2alpha. The GTPase domain of SEPT9_v1 was identified as essential for HIF-1alpha binding. A GTPase domain-derived polypeptide, corresponding to amino acids 252-379, was able to disrupt HIF-1alpha-SEPT9_v1 interaction and to inhibit HIF-1 transcriptional activity. SEPT9_v1 also protected HIF-1alpha from degradation induced by HSP90 inhibition by preventing the interaction of HIF-1alpha with the RACK1 protein, which promotes its oxygen-independent proteasomal degradation. In conclusion, a new mechanism of oxygen-independent activation of HIF-1 has been identified that is mediated by SEPT9_v1 blockade of RACK1 activity on HIF-1alpha degradation.
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Affiliation(s)
- Sharon Amir
- Prostate Cancer Research Laboratory, Department of Urology, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 64239, Israel
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MafG controls the hypoxic response of cells by accumulating HIF-1α in the nuclei. FEBS Lett 2008; 582:2357-64. [DOI: 10.1016/j.febslet.2008.05.040] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 05/19/2008] [Accepted: 05/23/2008] [Indexed: 11/18/2022]
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Fei GH, Feng ZP. Chronic hypoxia-induced alteration of presynaptic protein profiles and neurobehavioral dysfunction are averted by supplemental oxygen in Lymnaea stagnalis. Neuroscience 2008; 153:318-28. [DOI: 10.1016/j.neuroscience.2008.01.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Revised: 01/16/2008] [Accepted: 01/28/2008] [Indexed: 11/28/2022]
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Milkiewicz M, Doyle JL, Fudalewski T, Ispanovic E, Aghasi M, Haas TL. HIF-1alpha and HIF-2alpha play a central role in stretch-induced but not shear-stress-induced angiogenesis in rat skeletal muscle. J Physiol 2007; 583:753-66. [PMID: 17627993 PMCID: PMC2277012 DOI: 10.1113/jphysiol.2007.136325] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Angiogenesis, which is essential for the physiological adaptation of skeletal muscle to exercise, occurs in response to the mechanical forces of elevated capillary shear stress and cell stretch. Increased production of VEGF is a characteristic of endothelial cells undergoing either stretch- or shear-stress-induced angiogenesis. Because VEGF production is regulated by hypoxia inducible factors (HIFs), we examined whether HIFs play a significant role in the angiogenic process initiated by these mechanical forces. Rat extensor digitorum longus (EDL) muscles were overloaded to induce stretch, or exposed to the dilator prazosin to elevate capillary shear stress, and capillaries from these muscles were isolated by laser capture microdissection for RNA analysis. HIF-1alpha and HIF-2alpha transcript levels increased after 4 and 7 days of stretch, whereas a transient early induction of HIF-1alpha and HIF-2alpha transcripts was detected in capillaries from prazosin-treated muscles. Skeletal muscle microvascular endothelial cells exposed to 10% stretch in vitro showed an elevation in HIF-1alpha and HIF-2alpha mRNA, which was preceded by increases in HIF-binding activity. Conversely, HIF-1alpha and HIF-2alpha mRNA were reduced significantly, and HIF-alpha proteins were undetectable, after 24 h exposure to elevated shear stress (16 dyn cm(-2) (16 x10(-5) N cm(-2)). Given the disparate regulation of HIFs in response to these mechanical stimuli, we tested the requirement of HIF-alpha proteins in stretch- and shear-stress-induced angiogenesis by impeding HIF accumulation through use of the geldanamycin derivative 17-DMAG. Treatment with 17-DMAG significantly impaired stretch-induced, but not shear-stress-induced, angiogenesis. Together, these results illustrate that activation of HIF-1alpha and HIF-2alpha contributes significantly to stretch- but not to shear-stress-induced capillary growth.
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MESH Headings
- Adaptation, Physiological
- Animals
- Basic Helix-Loop-Helix Transcription Factors/genetics
- Basic Helix-Loop-Helix Transcription Factors/metabolism
- Benzoquinones/pharmacology
- Capillaries/enzymology
- Capillaries/metabolism
- Cells, Cultured
- Endothelial Cells/enzymology
- Endothelial Cells/metabolism
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Gene Expression Regulation
- HSP90 Heat-Shock Proteins/antagonists & inhibitors
- HSP90 Heat-Shock Proteins/metabolism
- Hypoxia-Inducible Factor 1, alpha Subunit/genetics
- Hypoxia-Inducible Factor 1, alpha Subunit/metabolism
- Indoles/pharmacology
- Lactams, Macrocyclic/pharmacology
- Male
- Mechanoreceptors/metabolism
- Mechanotransduction, Cellular
- Muscle, Skeletal/blood supply
- Neovascularization, Physiologic/drug effects
- Neovascularization, Physiologic/genetics
- Phosphorylation
- Prazosin/pharmacology
- Protein Kinase Inhibitors/pharmacology
- Pyrroles/pharmacology
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Stress, Mechanical
- Time Factors
- Vascular Endothelial Growth Factor A/metabolism
- Vascular Endothelial Growth Factor Receptor-2/antagonists & inhibitors
- Vascular Endothelial Growth Factor Receptor-2/metabolism
- Vasodilation/drug effects
- Vasodilation/genetics
- Vasodilator Agents/pharmacology
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Affiliation(s)
- Malgorzata Milkiewicz
- School of Kinesiology and Health Sciences, York University, Toronto, Ontario, Canada
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Oh SH, Woo JK, Yazici YD, Myers JN, Kim WY, Jin Q, Hong SS, Park HJ, Suh YG, Kim KW, Hong WK, Lee HY. Structural basis for depletion of heat shock protein 90 client proteins by deguelin. J Natl Cancer Inst 2007; 99:949-61. [PMID: 17565155 DOI: 10.1093/jnci/djm007] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND The molecular chaperone heat shock protein 90 (Hsp90) participates in preserving the expression and activity of various oncoproteins, including hypoxia-inducible factor 1alpha (HIF-1alpha) and Akt. Deguelin is a rotenoid with antitumor activities. We investigated whether the antitumor activities of deguelin involve the functional inhibition of Hsp90. METHOD Human xenograft tumors were generated in mice from H1299 (n = 6 per group) and A549 (n = 4 per group) non-small-cell lung cancer cells, UMSCC38 (n = 5 per group) head and neck cancer cells, MKN45 (n = 5 per group) stomach cancer cells, and PC-3 (n = 3 per group) prostate cancer cells. Tumor-bearing mice were treated with deguelin at 4 or 8 mg/kg or with vehicle (as a control) twice a day by oral gavage for 15-28 days. Protein expression was assessed by western blot analysis. Akt and Hsp90 were assessed by use of adenoviral vectors expressing constitutively active Akt or Hsp90. Binding of deguelin to Hsp90 was examined by docking analysis and by competition binding experiments with ATP-Sepharose beads. The proteasome inhibitor MG132 was used to investigate deguelin's effect on the induction of ubiquitin-mediated proteasomal degradation of HIF-1alpha. All statistical tests were two-sided. RESULTS Deguelin bound to the ATP-binding pocket of Hsp90 and disrupted Hsp90 function, leading to ubiquitin-mediated degradation of HIF-1alpha. Administration of deguelin to xenograft-bearing mice statistically significantly decreased tumor growth by inducing apoptosis and decreasing the expression of Hsp90 client proteins, without detectable toxic effects. For example, at 15 days after the start of deguelin treatment, the volume of untreated control H1299 xenograft tumors was 798 mm3 and that of xenograft tumors treated with deguelin at 4 mg/kg was 115.9 mm3 (difference = 682.1 mm3, 95% confidence interval = 480.4 to 883.9 mm3; P<.001). CONCLUSIONS The antitumor activities of deguelin appear to involve its binding to the ATP-binding pocket of Hsp90, which suppresses Hsp90 function.
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Affiliation(s)
- Seung Hyun Oh
- Department of Thoracic/Head and Neck Medical Oncology, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA
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40
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Kim HJ, Chung H, Yoo YG, Kim H, Lee JY, Lee MO, Kong G. Inhibitor of DNA binding 1 activates vascular endothelial growth factor through enhancing the stability and activity of hypoxia-inducible factor-1alpha. Mol Cancer Res 2007; 5:321-9. [PMID: 17426247 DOI: 10.1158/1541-7786.mcr-06-0218] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Inhibitor of DNA binding 1 (Id-1) has been implicated in tumor angiogenesis by regulating the expression of vascular endothelial growth factor (VEGF), but its molecular mechanism has not been fully understood. Here, we show the cross talk between Id-1 and hypoxia-inducible factor-1alpha (HIF-1alpha), that Id-1 induces VEGF by enhancing the stability and activity of HIF-1alpha in human endothelial and breast cancer cells. Although both the transcript and proteins levels of VEGF were induced by Id-1, only the protein expression of HIF-1alpha was induced without transcriptional changes in both human umbilical endothelial cells and MCF7 breast cancer cells. Such induction of the HIF-1alpha protein did not require de novo protein synthesis but was dependent on the active extracellular response kinase (ERK) pathway. In addition, stability of the HIF-1alpha protein was enhanced in part by the reduced association of the HIF-1alpha protein with von Hippel-Lindau protein in the presence of Id-1. Furthermore, Id-1 enhanced nuclear translocation and the transcriptional activity of HIF-1alpha. Transcriptional activation of HIF-1-dependent promoters was dependent on the active ERK pathway, and the association of HIF-1alpha protein with cyclic AMP-responsive element binding protein was enhanced by Id-1. Finally, Id-1 induced tube formation in human umbilical endothelial cells, which also required active ERK signaling. In conclusion, we provide the molecular mechanism of the cross talk between HIF-1alpha and Id-1, which may play a critical role in tumor angiogenesis.
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Affiliation(s)
- Hyun-Jun Kim
- Department of Pathology, College of Medicine, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791, Republic of Korea
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Li F, Sonveaux P, Rabbani ZN, Liu S, Yan B, Huang Q, Vujaskovic Z, Dewhirst MW, Li CY. Regulation of HIF-1alpha stability through S-nitrosylation. Mol Cell 2007; 26:63-74. [PMID: 17434127 PMCID: PMC2905600 DOI: 10.1016/j.molcel.2007.02.024] [Citation(s) in RCA: 339] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2006] [Revised: 01/15/2007] [Accepted: 02/20/2007] [Indexed: 12/25/2022]
Abstract
Hypoxia-inducible factor 1 (HIF-1) is a master transcriptional factor. Under normal oxygen tension, HIF-1 activity is usually suppressed due to the rapid, oxygen-dependent degradation of one of its two subunits, HIF-1alpha. Here we report that normoxic HIF-1 activity can be upregulated through NO-mediated S-nitrosylation and stabilization of HIF-1alpha. In murine tumors, exposure to ionizing radiation stimulated the generation of NO in tumor-associated macrophages. As a result, the HIF-1alpha protein is S-nitrosylated at Cys533 (through "biotin switch" assay) in the oxygen-dependent degradation domain, which prevents its destruction. Importantly, this mechanism appears to be independent of the prolylhydroxylase-based pathway that is involved in oxygen-dependent regulation of HIF-1alpha. Selective disruption of this S-nitrosylation significantly attenuated both radiation-induced and macrophage-induced activation of HIF-1alpha. This interaction between NO and HIF-1 sheds new light on their involvement in tumor response to treatment as well as mammalian inflammation process in general.
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Affiliation(s)
- Fang Li
- Department of Radiation Oncology, University of Colorado Health Sciences Center, Aurora, CO 80045
| | - Pierre Sonveaux
- Unit of Pharmacology & Therapeutics, University of Louvain (UCL) Medical School, Avenue E. Mounier, 53B, B-1200 Brussels, Belgium
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710
| | - Zahid N. Rabbani
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710
| | - Shanling Liu
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710
- West China 2 University Hospital, Sichuan University, Chengdu, China
| | - Bin Yan
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710
| | - Qian Huang
- No.1 People’s Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Zeljko Vujaskovic
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710
| | - Mark W. Dewhirst
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710
| | - Chuan-Yuan Li
- Department of Radiation Oncology, University of Colorado Health Sciences Center, Aurora, CO 80045
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710
- Correspondence: Chuan-Yuan Li, Dept. of Radiation Oncology, University of Colorado Health Sciences Center, P.O. Box 6511, MS 8111, Aurora, CO 80045, Tel: 303-724-1542, Fax: 303-724-1554,
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42
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Liu YV, Baek JH, Zhang H, Diez R, Cole RN, Semenza GL. RACK1 competes with HSP90 for binding to HIF-1alpha and is required for O(2)-independent and HSP90 inhibitor-induced degradation of HIF-1alpha. Mol Cell 2007; 25:207-17. [PMID: 17244529 PMCID: PMC2563152 DOI: 10.1016/j.molcel.2007.01.001] [Citation(s) in RCA: 373] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Revised: 10/26/2006] [Accepted: 01/02/2007] [Indexed: 11/17/2022]
Abstract
Hypoxia-inducible factor 1 (HIF-1) regulates transcription in response to changes in O(2) concentration. O(2)-dependent degradation of the HIF-1alpha subunit is mediated by prolyl hydroxylase (PHD), the von Hippel-Lindau (VHL)/Elongin-C/Elongin-B E3 ubiquitin ligase complex, and the proteasome. Inhibition of heat-shock protein 90 (HSP90) leads to O(2)/PHD/VHL-independent degradation of HIF-1alpha. We have identified the receptor of activated protein kinase C (RACK1) as a HIF-1alpha-interacting protein that promotes PHD/VHL-independent proteasomal degradation of HIF-1alpha. RACK1 competes with HSP90 for binding to the PAS-A domain of HIF-1alpha in vitro and in human cells. HIF-1alpha degradation induced by the HSP90 inhibitor 17-allylaminogeldanamycin is abolished by RACK1 loss of function. RACK1 binds to Elongin-C and promotes ubiquitination of HIF-1alpha. Elongin-C-binding sites in RACK1 and VHL show significant sequence similarity. Thus, RACK1 is an essential component of an O(2)/PHD/VHL-independent mechanism for regulating HIF-1alpha stability through competition with HSP90 and recruitment of the Elongin-C/B ubiquitin ligase complex.
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Affiliation(s)
- Ye V. Liu
- Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine Baltimore, Maryland 21205
- McKusick-Nathans Institute of Genetic Medicine, The Johns Hopkins University School of Medicine Baltimore, Maryland 21205
| | - Jin H. Baek
- Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine Baltimore, Maryland 21205
- McKusick-Nathans Institute of Genetic Medicine, The Johns Hopkins University School of Medicine Baltimore, Maryland 21205
| | - Huafeng Zhang
- Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine Baltimore, Maryland 21205
- McKusick-Nathans Institute of Genetic Medicine, The Johns Hopkins University School of Medicine Baltimore, Maryland 21205
| | - Roberto Diez
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine Baltimore, Maryland 21205
| | - Robert N. Cole
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine Baltimore, Maryland 21205
| | - Gregg L. Semenza
- Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine Baltimore, Maryland 21205
- McKusick-Nathans Institute of Genetic Medicine, The Johns Hopkins University School of Medicine Baltimore, Maryland 21205
- Departments of Pediatrics, Medicine, Oncology, and Radiation Oncology, The Johns Hopkins University School of Medicine Baltimore, Maryland 21205
- Correspondence: Broadway Research Building, Suite 671, 733 N. Broadway, Baltimore, MD 21205; TEL 410-955-1619; FAX 443-287-5618; Email
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Yan Q, Bartz S, Mao M, Li L, Kaelin WG. The hypoxia-inducible factor 2alpha N-terminal and C-terminal transactivation domains cooperate to promote renal tumorigenesis in vivo. Mol Cell Biol 2007; 27:2092-102. [PMID: 17220275 PMCID: PMC1820491 DOI: 10.1128/mcb.01514-06] [Citation(s) in RCA: 150] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Hypoxia-inducible factor (HIF) is a heterodimeric transcription factor, consisting of an alpha subunit and a beta subunit, that controls cellular responses to hypoxia. HIFalpha contains two transcriptional activation domains called the N-terminal transactivation domain (NTAD) and the C-terminal transactivation domain (CTAD). HIFalpha is destabilized by prolyl hydroxylation catalyzed by EglN family members. In addition, CTAD function is inhibited by asparagine hydroxylation catalyzed by FIH1. Both hydroxylation reactions are linked to oxygen availability. The von Hippel-Lindau tumor suppressor protein (pVHL) is frequently mutated in kidney cancer and is part of the ubiquitin ligase complex that targets prolyl hydroxylated HIFalpha for destruction. Recent studies suggest that HIF2alpha plays an especially important role in promoting tumor formation by pVHL-defective renal carcinoma cells among the three HIFalpha paralogs. Here we dissected the relative contribution of the two HIF2alpha transactivation domains to hypoxic gene activation and renal carcinogenesis and investigated the regulation of the HIF2alpha CTAD by FIH1. We found that the HIF2alpha NTAD is capable of activating both artificial and naturally occurring HIF-responsive promoters in the absence of the CTAD. Moreover, we found that the HIF2alpha CTAD, in contrast to the HIF1alpha CTAD, is relatively resistant to the inhibitory effects of FIH1 under normoxic conditions and that, perhaps as a result, both the NTAD and CTAD cooperate to promote renal carcinogenesis in vivo.
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Affiliation(s)
- Qin Yan
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
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Sun HL, Liu YN, Huang YT, Pan SL, Huang DY, Guh JH, Lee FY, Kuo SC, Teng CM. YC-1 inhibits HIF-1 expression in prostate cancer cells: contribution of Akt/NF-kappaB signaling to HIF-1alpha accumulation during hypoxia. Oncogene 2007; 26:3941-51. [PMID: 17213816 DOI: 10.1038/sj.onc.1210169] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Hypoxia-inducible factor 1 (HIF-1), a transcription factor that is critical for tumor adaptation to microenvironmental stimuli, represents an attractive chemotherapeutic target. YC-1 is a novel antitumor agent that inhibits HIF-1 through previously unexplained mechanisms. In the present study, YC-1 was found to prevent HIF-1alpha and HIF-1beta accumulation in response to hypoxia or mitogen treatment in PC-3 prostate cancer cells. Neither HIF-1alpha protein half-life nor mRNA level was affected by YC-1. However, YC-1 was found to suppress the PI3K/Akt/mTOR/4E-BP pathway, which serves to regulate HIF-1alpha expression at the translational step. We demonstrated that YC-1 also inhibited hypoxia-induced activation of nuclear factor (NF)-kappaB, a downstream target of Akt. Two modulators of the Akt/NF-kappaB pathway, caffeic acid phenethyl ester and evodiamine, were observed to decrease HIF-1alpha expression. Additionally, overexpression of NF-kappaB partly reversed the ability of wortmannin to inhibit HIF-1alpha-dependent transcriptional activity, suggesting that NF-kappaB contributes to Akt-mediated HIF-1alpha accumulation during hypoxia. Overall, we identify a potential molecular mechanism whereby YC-1 serves to reduce HIF-1 expression.
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Affiliation(s)
- H-L Sun
- Pharmacological Institute, College of Medicine, National Taiwan University, Taipei, Taiwan
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Scheuermann TH, Yang J, Zhang L, Gardner KH, Bruick RK. Hypoxia-inducible factors Per/ARNT/Sim domains: structure and function. Methods Enzymol 2007; 435:3-24. [PMID: 17998046 DOI: 10.1016/s0076-6879(07)35001-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Hypoxia-inducible factors (HIFs) are key transcriptional regulators of genes involved in cellular adaptation to reduced oxygen availability through effects on anaerobic metabolism, oxygen delivery, angiogenesis, and cellular survival and proliferation. As such, HIFs contribute to the pathogenesis of diseases in which oxygen availability is compromised, notably ischemia and tumorigenesis. Though tremendous progress has been made in elucidating the mechanisms underlying O(2)-dependent regulation of HIF by Fe(II)- and 2-oxoglutarate-dependent dioxygenases, HIF induction can be uncoupled from these modes of regulation in diseases such as cancer. Consequently, renewed interest has developed in understanding the structure/function relationships of individual P(er)/ARNT/S(im) (PAS) domains that are important for maintaining transcriptionally active HIF complexes, regardless of the manner by which HIF is induced. This review highlights strategies for the biophysical and biochemical characterization of the PAS domains found within both HIF subunits and provides a platform for future efforts to exploit these domains in therapeutic settings.
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Affiliation(s)
- Thomas H Scheuermann
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Lim JH, Park JW, Kim SJ, Kim MS, Park SK, Johnson RS, Chun YS. ATP6V0C competes with von Hippel-Lindau protein in hypoxia-inducible factor 1alpha (HIF-1alpha) binding and mediates HIF-1alpha expression by bafilomycin A1. Mol Pharmacol 2006; 71:942-8. [PMID: 17178925 DOI: 10.1124/mol.106.030296] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
HIF-1alpha not only enables cells to survive under hypoxic conditions but also promotes cell cycle arrest and apoptosis. Therefore, its expression should be controlled at optimal levels in growing tumors. We recently reported that bafilomycin A1 exorbitantly expressed HIF-1alpha and induced the p21(WAF1/Cip1)-mediated growth arrest of tumors (Mol Pharmacol 70:1856-1865, 2006). In the present study, we addressed the mechanism underlying bafilomycin-induced HIF-1alpha expression. Bafilomycin stabilized HIF-1alpha under normoxic conditions without changes in intracellular pH. However, when ATP6V0C, the target protein of bafilomycin, was knocked down, this bafilomycin effect was significantly attenuated. Inversely, ATP6V0C expression increased HIF-1alpha levels in a gene dose-dependent manner. ATP6V0C competed with Von Hippel-Lindau protein in HIF-1alpha binding by directly interacting with HIF-1alpha, which was stimulated by bafilomycin. In confocal images, ATP6V0C was normally present in the cytoplasm but was translocated in company with HIF-1alpha to the nucleus by bafilomycin. The N-terminal end (amino acids 1-16) of HIF-1alpha was identified as the ATP6V0C-interacting motif. These results suggest that ATP6V0C, a novel regulator of HIF-1alpha, mediates HIF-1alpha expression by bafilomycin.
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Affiliation(s)
- Ji-Hong Lim
- Cancer Research Institute, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-799, Korea
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Arjamaa O, Nikinmaa M. Oxygen-dependent diseases in the retina: Role of hypoxia-inducible factors. Exp Eye Res 2006; 83:473-83. [PMID: 16750526 DOI: 10.1016/j.exer.2006.01.016] [Citation(s) in RCA: 192] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2005] [Revised: 01/04/2006] [Accepted: 01/05/2006] [Indexed: 12/30/2022]
Abstract
The function of the retina is sensitive to oxygen tension. Any change in the perfusion pressure of the eye affects the retina although the eye is able to autoregulate its hemodynamics. Systemic hypoxemia (lung or heart disease) or a vascular disease in the retina can cause retinal hypoxia. All the hypoxia-dependent events in cells appear to share a common denominator: hypoxia-inducible factor (HIF), which is a heterodimeric transcription factor, a protein. HIF comprises a labile alpha subunit (1-3), which is regulated, and a stable beta subunit, which is constitutively expressed. Both are helix-loop-helix factors and belong to the PAS-domain family of transcription factors. Oxygen plays the key role in stabilizing HIF-1alpha and its function. When the oxygen tension is normal, HIF-1alpha is rapidly oxidized by hydroxylase enzymes, but when cells become hypoxic, HIF-1alpha escapes the degradation and starts to accumulate, triggering the activation of a large number of genes, like vascular endothelial growth factor (VEGF) and erythropoietin. HIF-1alpha has been shown to have, either clinically or experimentally, a mediating or contributing role in several oxygen-dependent retinal diseases such as von Hippel-Lindau, proliferative diabetic retinopathy, retinopathy of prematurity and glaucoma. In retinitis pigmentosa and high-altitude retinopathy, however, the evidence is still indirect. There are three different strategies available for treating retinal diseases, which have all shown promising results: retinal cell transplantation or replacement, gene replacement, and pharmacological intervention. Specifically, recent results show that the HIF pathway can be used as a therapeutic target, although there is still a long way to go from bench to clinic. HIF can be stabilized by inhibiting prolyl hydroxylase or by blocking the VHL:HIF-alpha complex if angiogenesis is the goal, as in retinitis pigmentosa. On the other hand, the downregulation of HIF has a pivotal role if we are to inhibit neovascularization, as in proliferative diabetic retinopathy. To date, several small-molecule inhibitors of HIF have been developed and are entering clinical trials. HIF is a remarkable example of a single transcription factor that can be regarded as a "master switch" regulating all the oxygen-dependent retinal diseases.
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Affiliation(s)
- Olli Arjamaa
- Laboratory of Animal Physiology, Department of Biology, Center of Excellence in Evolutionary Genetics and Physiology, 20014 University of Turku, Finland.
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Merighi S, Benini A, Mirandola P, Gessi S, Varani K, Leung E, Maclennan S, Borea PA. Adenosine modulates vascular endothelial growth factor expression via hypoxia-inducible factor-1 in human glioblastoma cells. Biochem Pharmacol 2006; 72:19-31. [PMID: 16682012 DOI: 10.1016/j.bcp.2006.03.020] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2006] [Revised: 03/13/2006] [Accepted: 03/23/2006] [Indexed: 11/25/2022]
Abstract
Hypoxia appears to induce a program which shifts the cellular phenotype toward an increase in extracellular adenosine. Hypoxia-inducible factor-1 (HIF-1) is a key regulator of genes crucial to many aspects of cancer biology. Since in gliomas there is a strong correlation between HIF-1alpha expression, tumor grade and tumor vascularization, the aim of this study was to investigate whether adenosine may regulate HIF-1 in human glioblastoma cell lines. The results indicate that in the human hypoxic A172 and U87MG glioblastoma cell lines adenosine up-regulates HIF-1alpha protein expression via the A(3) receptor subtype. In particular, we investigated the effect of A(3) receptor antagonists on HIF-1 and vascular endothelial growth factor (VEGF) expression. We found that A(3) antagonists inhibit adenosine-induced HIF-1alpha and VEGF protein accumulation in the hypoxic cells. Investigations in the molecular mechanism showed that A(3) receptor stimulation activates p44/p42 and p38 MAPKs that are required for A(3)-induced increase of HIF-1alpha and VEGF. Further studies are required to demonstrate the in vivo relevance of these observations with regard to the proposed role for adenosine as a key element in hypoxia and in tumors.
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MESH Headings
- Adenosine/pharmacology
- Adenosine A3 Receptor Antagonists
- Blotting, Western
- Cell Hypoxia/physiology
- Cell Line, Tumor
- Dose-Response Relationship, Drug
- Enzyme-Linked Immunosorbent Assay
- Gene Expression Regulation, Neoplastic/drug effects
- Gene Silencing
- Glioblastoma/drug therapy
- Glioblastoma/metabolism
- Humans
- Hypoxia-Inducible Factor 1, alpha Subunit/genetics
- Hypoxia-Inducible Factor 1, alpha Subunit/metabolism
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3/metabolism
- Phenylurea Compounds/pharmacology
- RNA, Messenger/metabolism
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- Receptor, Adenosine A3/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Triazoles/pharmacology
- Up-Regulation
- Vascular Endothelial Growth Factor A/genetics
- Vascular Endothelial Growth Factor A/metabolism
- p38 Mitogen-Activated Protein Kinases/metabolism
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Affiliation(s)
- Stefania Merighi
- Department of Clinical and Experimental Medicine, Pharmacology Unit, University of Ferrara, 44100 Ferrara, Italy
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Nagle DG, Zhou YD. Natural product-based inhibitors of hypoxia-inducible factor-1 (HIF-1). Curr Drug Targets 2006; 7:355-69. [PMID: 16515532 PMCID: PMC2908043 DOI: 10.2174/138945006776054979] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The transcription factor hypoxia-inducible factor-1 (HIF-1) regulates the expression of more than 70 genes involved in cellular adaptation and survival under hypoxic stress. Activation of HIF-1 is associated with numerous physiological and pathological processes that include tumorigenesis, vascular remodeling, inflammation, and hypoxia/ischemia-related tissue damage. Clinical studies suggested that HIF-1 activation correlates directly with advanced disease stages and treatment resistance among cancer patients. Preclinical studies support the inhibition of HIF-1 as a major molecular target for antitumor drug discovery. Considerable effort is underway, in government laboratories, industry and academia, to identify therapeutically useful small molecule HIF-1 inhibitors. Natural products (low molecular weight organic compounds produced by plants, microbes, and animals) continue to play a major role in modern antitumor drug discovery. Most of the compounds discovered to inhibit HIF-1 are natural products or synthetic compounds with structures that are based on natural product leads. Natural products have also served a vital role as molecular probes to elucidate the pathways that regulate HIF-1 activity. Natural products and natural product-derived compounds that inhibit HIF-1 are summarized in light of their biological source, chemical class, and effect on HIF-1 and HIF-mediated gene regulation. When known, the mechanism(s) of action of HIF-1 inhibitors are described. Many of the substances found to inhibit HIF-1 are non-druggable compounds that are too cytotoxic to serve as drug leads. The application of high-throughput screening methods, complementary molecular-targeted assays, and structurally diverse chemical libraries hold promise for the discovery of therapeutically useful HIF-1 inhibitors.
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Affiliation(s)
- Dale G. Nagle
- Joint Corresponding Authors to whom correspondence should be addressed.: Dale G. Nagle: Tel. (662) 915-7026. Fax: (662) 915-6975. ., Yu-Dong Zhou: Tel: (662) 915-1577. Fax: (662) 915-7062.
| | - Yu-Dong Zhou
- Joint Corresponding Authors to whom correspondence should be addressed.: Dale G. Nagle: Tel. (662) 915-7026. Fax: (662) 915-6975. ., Yu-Dong Zhou: Tel: (662) 915-1577. Fax: (662) 915-7062.
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Schwock J, Geddie WR, Hedley DW. Analysis of hypoxia-inducible factor-1alpha accumulation and cell cycle in geldanamycin-treated human cervical carcinoma cells by laser scanning cytometry. Cytometry A 2006; 68:59-70. [PMID: 16228978 DOI: 10.1002/cyto.a.20192] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Tumor hypoxia has been linked to increased disease aggressiveness and poorer treatment outcomes, and the transcription factor hypoxia-inducible factor-1 (HIF-1) has been identified as the key molecule mediating the cellular response to hypoxic microenvironments. The alpha-subunit of this factor is accumulated under hypoxia and rapidly degraded during re-oxygenation, rendering the reliable measurement of HIF-1alpha a difficult task. Heat shock protein 90 (Hsp90) is an essential protein that controls the activity, turnover, and trafficking of a variety of other proteins including HIF-1alpha and cell cycle regulators. Hsp90 inhibitors like geldanamycin therefore have the potential to target tumor-cell survival by at least two mechanisms, compromising the accumulation of HIF-1alpha and cell proliferation. METHODS We describe here the simultaneous measurement of HIF-1alpha and cell cycle parameters by laser scanning cytometry (LSC) after exposure of two different human cervical carcinoma cell lines to hypoxia and geldanamycin. RESULTS Our analysis demonstrates that the cell lines react to hypoxia and drug treatment in a distinct way, with SiHa being more affected by low oxygen concentrations than is ME180, which was more sensitive to geldanamycin treatment. Both cell lines respond to geldanamycin with a G(2)/M-phase arrest and a decrease in HIF-1alpha accumulation. Cell death due to geldanamycin occurs in association with mitosis, presumably through mitotic catastrophe. CONCLUSION Our results indicate that LSC can significantly contribute to the evaluation of in vitro drug effects particularly with respect to tumor hypoxia and the measurement of HIF-1alpha.
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Affiliation(s)
- Jörg Schwock
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
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