60 results on '"Bourboulia, Dimitra"'
Search Results
2. Editorial: A new chapter for Cell Stress and Chaperones.
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Bourboulia D, Blair LJ, Clark MS, Edkins AL, Hightower LE, Mollapour M, Prahlad V, Repasky EA, Truebano M, Truman AW, Truttmann MC, van Oosten-Hawle P, and Woodford MR
- Subjects
- Molecular Chaperones metabolism, Oxidative Stress
- Published
- 2024
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3. Activation of autophagy depends on Atg1/Ulk1-mediated phosphorylation and inhibition of the Hsp90 chaperone machinery.
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Backe SJ, Sager RA, Heritz JA, Wengert LA, Meluni KA, Aran-Guiu X, Panaretou B, Woodford MR, Prodromou C, Bourboulia D, and Mollapour M
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- 2024
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4. Protocol to characterize extracellular c-Src tyrosine kinase function through substrate interaction and phosphorylation.
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Omini MP, Alsalih D, Votra SD, and Bourboulia D
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- Humans, Phosphorylation, CSK Tyrosine-Protein Kinase metabolism, Tyrosine metabolism, src-Family Kinases metabolism, Protein-Tyrosine Kinases chemistry, Protein-Tyrosine Kinases metabolism
- Abstract
Cellular Src tyrosine kinase (c-Src) exists in the secretomes of several human cancers (extracellular, e-Src). Phosphoproteomics has demonstrated the existence of 114 potential extracellular e-Src substrates in addition to Tissue Inhibitor of Metalloproteinases 2. Here, we present a protocol to characterize secreted tyrosine-phosphorylated substrates as a result of c-Src expression and secretion. We describe steps for collecting cell secretomes and extracts, performing antibody treatment and Ni-NTA pull-down, and detecting protein-protein interaction and substrate Y-phosphorylation. This protocol is adaptable for studies examining the function of other extracellular kinases. For complete details on the use and execution of this protocol, please refer to Backe et al. (2023)
1 and Sánchez-Pozo et al. (2018).2 ., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2023
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5. Catalytic inhibitor of Protein Phosphatase 5 activates the extrinsic apoptotic pathway by disrupting complex II in kidney cancer.
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Ahanin EF, Sager RA, Backe SJ, Dunn DM, Dushukyan N, Blanden AR, Mate NA, Suzuki T, Anderson T, Roy M, Oberoi J, Prodromou C, Nsouli I, Daneshvar M, Bratslavsky G, Woodford MR, Bourboulia D, Chisholm JD, and Mollapour M
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- Humans, Nuclear Proteins metabolism, Apoptosis, Phosphoprotein Phosphatases, Kidney Neoplasms drug therapy
- Abstract
Serine/threonine protein phosphatase-5 (PP5) is involved in tumor progression and survival, making it an attractive therapeutic target. Specific inhibition of protein phosphatases has remained challenging because of their conserved catalytic sites. PP5 contains its regulatory domains within a single polypeptide chain, making it a more desirable target. Here we used an in silico approach to screen and develop a selective inhibitor of PP5. Compound P053 is a competitive inhibitor of PP5 that binds to its catalytic domain and causes apoptosis in renal cancer. We further demonstrated that PP5 interacts with FADD, RIPK1, and caspase 8, components of the extrinsic apoptotic pathway complex II. Specifically, PP5 dephosphorylates and inactivates the death effector protein FADD, preserving complex II integrity and regulating extrinsic apoptosis. Our data suggests that PP5 promotes renal cancer survival by suppressing the extrinsic apoptotic pathway. Pharmacologic inhibition of PP5 activates this pathway, presenting a viable therapeutic strategy for renal cancer., Competing Interests: Declaration of interests The authors declare no competing financial interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)
- Published
- 2023
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6. Epichaperomics reveals dysfunctional chaperone protein networks.
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Woodford MR, Bourboulia D, and Mollapour M
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- Molecular Chaperones genetics
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- 2023
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7. Activation of autophagy depends on Atg1/Ulk1-mediated phosphorylation and inhibition of the Hsp90 chaperone machinery.
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Backe SJ, Sager RA, Heritz JA, Wengert LA, Meluni KA, Aran-Guiu X, Panaretou B, Woodford MR, Prodromou C, Bourboulia D, and Mollapour M
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- Animals, Phosphorylation, Autophagy-Related Protein-1 Homolog metabolism, Saccharomyces cerevisiae metabolism, Serine metabolism, Mammals metabolism, Autophagy physiology, HSP90 Heat-Shock Proteins metabolism
- Abstract
Cellular homeostasis relies on both the chaperoning of proteins and the intracellular degradation system that delivers cytoplasmic constituents to the lysosome, a process known as autophagy. The crosstalk between these processes and their underlying regulatory mechanisms is poorly understood. Here, we show that the molecular chaperone heat shock protein 90 (Hsp90) forms a complex with the autophagy-initiating kinase Atg1 (yeast)/Ulk1 (mammalian), which suppresses its kinase activity. Conversely, environmental cues lead to Atg1/Ulk1-mediated phosphorylation of a conserved serine in the amino domain of Hsp90, inhibiting its ATPase activity and altering the chaperone dynamics. These events impact a conformotypic peptide adjacent to the activation and catalytic loop of Atg1/Ulk1. Finally, Atg1/Ulk1-mediated phosphorylation of Hsp90 leads to dissociation of the Hsp90:Atg1/Ulk1 complex and activation of Atg1/Ulk1, which is essential for initiation of autophagy. Our work indicates a reciprocal regulatory mechanism between the chaperone Hsp90 and the autophagy kinase Atg1/Ulk1 and consequent maintenance of cellular proteostasis., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)
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- 2023
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8. Extracellular HSP90 warms up integrins for an irisin workout.
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Bourboulia D, Woodford MR, and Mollapour M
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- Signal Transduction, Adipose Tissue metabolism, HSP90 Heat-Shock Proteins metabolism, Fibronectins metabolism, Integrins
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The hormone-like protein irisin is involved in browning of adipose tissue and regulation of metabolism. Recently, Mu et al. identified the extracellular chaperone heat shock protein-90 (Hsp90) as the activating factor for "opening" αVβ5 integrin receptor, allowing for high-affinity irisin binding and effective signal transduction., Competing Interests: Declaration of interests The authors declare no competing financial interests., (Copyright © 2023 Elsevier Inc. All rights reserved.)
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- 2023
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9. PhosY-secretome profiling combined with kinase-substrate interaction screening defines active c-Src-driven extracellular signaling.
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Backe SJ, Votra SD, Stokes MP, Sebestyén E, Castelli M, Torielli L, Colombo G, Woodford MR, Mollapour M, and Bourboulia D
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- Signal Transduction, Phosphotransferases, Phosphorylation, src Homology Domains, Cell Communication, src-Family Kinases, Protein-Tyrosine Kinases metabolism, Secretome
- Abstract
c-Src tyrosine kinase is a renowned key intracellular signaling molecule and a potential target for cancer therapy. Secreted c-Src is a recent observation, but how it contributes to extracellular phosphorylation remains elusive. Using a series of domain deletion mutants, we show that the N-proximal region of c-Src is essential for its secretion. The tissue inhibitor of metalloproteinases 2 (TIMP2) is an extracellular substrate of c-Src. Limited proteolysis-coupled mass spectrometry and mutagenesis studies verify that the Src homology 3 (SH3) domain of c-Src and the P
31 VHP34 motif of TIMP2 are critical for their interaction. Comparative phosphoproteomic analyses identify an enrichment of PxxP motifs in phosY-containing secretomes from c-Src-expressing cells with cancer-promoting roles. Inhibition of extracellular c-Src using custom SH3-targeting antibodies disrupt kinase-substrate complexes and inhibit cancer cell proliferation. These findings point toward an intricate role for c-Src in generating phosphosecretomes, which will likely influence cell-cell communication, particularly in c-Src-overexpressing cancers., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)- Published
- 2023
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10. Second Virtual International Symposium on Cellular and Organismal Stress Responses, September 8-9, 2022.
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van Oosten-Hawle P, Backe SJ, Ben-Zvi A, Bourboulia D, Brancaccio M, Brodsky J, Clark M, Colombo G, Cox MB, De Los Rios P, Echtenkamp F, Edkins A, Freeman B, Goloubinoff P, Houry W, Johnson J, LaPointe P, Li W, Mezger V, Neckers L, Nillegoda NB, Prahlad V, Reitzel A, Scherz-Shouval R, Sistonen L, Tsai FTF, Woodford MR, Mollapour M, and Truman AW
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- Humans, HSP70 Heat-Shock Proteins, Molecular Chaperones physiology, Stress, Physiological physiology
- Abstract
The Second International Symposium on Cellular and Organismal Stress Responses took place virtually on September 8-9, 2022. This meeting was supported by the Cell Stress Society International (CSSI) and organized by Patricija Van Oosten-Hawle and Andrew Truman (University of North Carolina at Charlotte, USA) and Mehdi Mollapour (SUNY Upstate Medical University, USA). The goal of this symposium was to continue the theme from the initial meeting in 2020 by providing a platform for established researchers, new investigators, postdoctoral fellows, and students to present and exchange ideas on various topics on cellular stress and chaperones. We will summarize the highlights of the meeting here and recognize those that received recognition from the CSSI., (© 2022. The Author(s).)
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- 2023
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11. Methods to Assess the Impact of Hsp90 Chaperone Function on Extracellular Client MMP2 Activity.
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Votra SD, Alsalih D, and Bourboulia D
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- Animals, Humans, Molecular Chaperones, HSP90 Heat-Shock Proteins metabolism, Extracellular Matrix metabolism, Mammals metabolism, Matrix Metalloproteinase 2 metabolism, Neoplasms
- Abstract
Secreted, or extracellular, heat shock protein 90 (eHsp90) is considered a recent discovery in eukaryotes. Over the last two decades, studies have provided significant supporting evidence that implicates eHsp90 both in normal cellular processes such as wound healing and in the development of human pathologies and diseases including fibrosis and cancer. In the early 2000s, Eustace et al. demonstrated that eHsp90 promotes the invasion of breast cancer cells by binding to and regulating the activity of an extracellular matrix (ECM) remodeling enzyme, the matrix metalloproteinase 2 or MMP2. Interestingly, inside mammalian cells, Hsp90 is an essential chaperone that interacts with hundreds of newly synthesized proteins, known as "clients," that require Hsp90's assistance to perform their function. Several methods are routinely used to characterize the role and impact of Hsp90 on a client protein's functionality in vitro and in vivo. However, the mechanistic role of eHsp90 is less well-defined since, so far, only a handful of extracellular client proteins have been identified. Here, we describe methods to characterize the impact of the secreted chaperone on MMP2 activity, the most characterized extracellular client of eHsp90. The procedures described here can be applied and adapted to characterize other extracellular clients, particularly members of the MMP family., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)
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- 2023
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12. Impact of Co-chaperones and Posttranslational Modifications Toward Hsp90 Drug Sensitivity.
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Backe SJ, Woodford MR, Ahanin E, Sager RA, Bourboulia D, and Mollapour M
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- Humans, Molecular Chaperones metabolism, Protein Processing, Post-Translational, Adenosine Triphosphate metabolism, HSP90 Heat-Shock Proteins genetics, HSP90 Heat-Shock Proteins metabolism, Neoplasms drug therapy
- Abstract
Posttranslational modifications (PTMs) regulate myriad cellular processes by modulating protein function and protein-protein interaction. Heat shock protein 90 (Hsp90) is an ATP-dependent molecular chaperone whose activity is responsible for the stabilization and maturation of more than 300 client proteins. Hsp90 is a substrate for numerous PTMs, which have diverse effects on Hsp90 function. Interestingly, many Hsp90 clients are enzymes that catalyze PTM, demonstrating one of the several modes of regulation of Hsp90 activity. Approximately 25 co-chaperone regulatory proteins of Hsp90 impact structural rearrangements, ATP hydrolysis, and client interaction, representing a second layer of influence on Hsp90 activity. A growing body of literature has also established that PTM of these co-chaperones fine-tune their activity toward Hsp90; however, many of the identified PTMs remain uncharacterized. Given the critical role of Hsp90 in supporting signaling in cancer, clinical evaluation of Hsp90 inhibitors is an area of great interest. Interestingly, differential PTM and co-chaperone interaction have been shown to impact Hsp90 binding to its inhibitors. Therefore, understanding these layers of Hsp90 regulation will provide a more complete understanding of the chaperone code, facilitating the development of new biomarkers and combination therapies., (© 2023. The Author(s), under exclusive license to Springer Nature Switzerland AG.)
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- 2023
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13. Targeting extracellular Hsp90: A unique frontier against cancer.
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Sager RA, Khan F, Toneatto L, Votra SD, Backe SJ, Woodford MR, Mollapour M, and Bourboulia D
- Abstract
The molecular chaperone Heat Shock Protein-90 (Hsp90) is known to interact with over 300 client proteins as well as regulatory factors (eg. nucleotide and proteins) that facilitate execution of its role as a chaperone and, ultimately, client protein activation. Hsp90 associates transiently with these molecular modulators during an eventful chaperone cycle, resulting in acquisition of flexible structural conformations, perfectly customized to the needs of each one of its client proteins. Due to the plethora and diverse nature of proteins it supports, the Hsp90 chaperone machinery is critical for normal cellular function particularly in response to stress. In diseases such as cancer, the Hsp90 chaperone machinery is hijacked for processes which encompass many of the hallmarks of cancer, including cell growth, survival, immune response evasion, migration, invasion, and angiogenesis. Elevated levels of extracellular Hsp90 (eHsp90) enhance tumorigenesis and the potential for metastasis. eHsp90 has been considered one of the new targets in the development of anti-cancer drugs as there are various stages of cancer progression where eHsp90 function could be targeted. Our limited understanding of the regulation of the eHsp90 chaperone machinery is a major drawback for designing successful Hsp90-targeted therapies, and more research is still warranted., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Sager, Khan, Toneatto, Votra, Backe, Woodford, Mollapour and Bourboulia.)
- Published
- 2022
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14. A specialized Hsp90 co-chaperone network regulates steroid hormone receptor response to ligand.
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Backe SJ, Sager RA, Regan BR, Sit J, Major LA, Bratslavsky G, Woodford MR, Bourboulia D, and Mollapour M
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- Hormones metabolism, Humans, Ligands, Protein Binding, Steroids metabolism, HSP90 Heat-Shock Proteins metabolism, Molecular Chaperones metabolism
- Abstract
Heat shock protein-90 (Hsp90) chaperone machinery is involved in the stability and activity of its client proteins. The chaperone function of Hsp90 is regulated by co-chaperones and post-translational modifications. Although structural evidence exists for Hsp90 interaction with clients, our understanding of the impact of Hsp90 chaperone function toward client activity in cells remains elusive. Here, we dissect the impact of recently identified higher eukaryotic co-chaperones, FNIP1/2 (FNIPs) and Tsc1, toward Hsp90 client activity. Our data show that Tsc1 and FNIP2 form mutually exclusive complexes with FNIP1, and that unlike Tsc1, FNIP1/2 interact with the catalytic residue of Hsp90. Functionally, these co-chaperone complexes increase the affinity of the steroid hormone receptors glucocorticoid receptor and estrogen receptor to their ligands in vivo. We provide a model for the responsiveness of the steroid hormone receptor activation upon ligand binding as a consequence of their association with specific Hsp90:co-chaperone subpopulations., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)
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- 2022
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15. Emerging Link between Tsc1 and FNIP Co-Chaperones of Hsp90 and Cancer.
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Backe SJ, Sager RA, Meluni KA, Woodford MR, Bourboulia D, and Mollapour M
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- HSP90 Heat-Shock Proteins metabolism, Humans, Molecular Chaperones, Tuberous Sclerosis metabolism, Tuberous Sclerosis Complex 1 Protein metabolism, Tumor Suppressor Proteins genetics, Tumor Suppressor Proteins metabolism
- Abstract
Heat shock protein-90 (Hsp90) is an ATP-dependent molecular chaperone that is tightly regulated by a group of proteins termed co-chaperones. This chaperone system is essential for the stabilization and activation of many key signaling proteins. Recent identification of the co-chaperones FNIP1, FNIP2, and Tsc1 has broadened the spectrum of Hsp90 regulators. These new co-chaperones mediate the stability of critical tumor suppressors FLCN and Tsc2 as well as the various classes of Hsp90 kinase and non-kinase clients. Many early observations of the roles of FNIP1, FNIP2, and Tsc1 suggested functions independent of FLCN and Tsc2 but have not been fully delineated. Given the broad cellular impact of Hsp90-dependent signaling, it is possible to explain the cellular activities of these new co-chaperones by their influence on Hsp90 function. Here, we review the literature on FNIP1, FNIP2, and Tsc1 as co-chaperones and discuss the potential downstream impact of this regulation on normal cellular function and in human diseases.
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- 2022
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16. TRAP1 Chaperones the Metabolic Switch in Cancer.
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Wengert LA, Backe SJ, Bourboulia D, Mollapour M, and Woodford MR
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- Glycolysis, Humans, Mitochondria metabolism, Molecular Chaperones metabolism, HSP90 Heat-Shock Proteins metabolism, Neoplasms metabolism, TNF Receptor-Associated Factor 1 metabolism
- Abstract
Mitochondrial function is dependent on molecular chaperones, primarily due to their necessity in the formation of respiratory complexes and clearance of misfolded proteins. Heat shock proteins (Hsps) are a subset of molecular chaperones that function in all subcellular compartments, both constitutively and in response to stress. The Hsp90 chaperone TNF-receptor-associated protein-1 (TRAP1) is primarily localized to the mitochondria and controls both cellular metabolic reprogramming and mitochondrial apoptosis. TRAP1 upregulation facilitates the growth and progression of many cancers by promoting glycolytic metabolism and antagonizing the mitochondrial permeability transition that precedes multiple cell death pathways. TRAP1 attenuation induces apoptosis in cellular models of cancer, identifying TRAP1 as a potential therapeutic target in cancer. Similar to cytosolic Hsp90 proteins, TRAP1 is also subject to post-translational modifications (PTM) that regulate its function and mediate its impact on downstream effectors, or 'clients'. However, few effectors have been identified to date. Here, we will discuss the consequence of TRAP1 deregulation in cancer and the impact of post-translational modification on the known functions of TRAP1.
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- 2022
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17. Therapeutic potential of CDK4/6 inhibitors in renal cell carcinoma.
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Sager RA, Backe SJ, Ahanin E, Smith G, Nsouli I, Woodford MR, Bratslavsky G, Bourboulia D, and Mollapour M
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- Cyclin-Dependent Kinase 4 metabolism, Cyclin-Dependent Kinase 4 therapeutic use, Female, Humans, Immune Checkpoint Inhibitors, Male, Protein Kinase Inhibitors pharmacology, Protein Kinase Inhibitors therapeutic use, TOR Serine-Threonine Kinases therapeutic use, Carcinoma, Renal Cell drug therapy, Kidney Neoplasms drug therapy
- Abstract
The treatment of advanced and metastatic kidney cancer has entered a golden era with the addition of more therapeutic options, improved survival and new targeted therapies. Tyrosine kinase inhibitors, mammalian target of rapamycin (mTOR) inhibitors and immune checkpoint blockade have all been shown to be promising strategies in the treatment of renal cell carcinoma (RCC). However, little is known about the best therapeutic approach for individual patients with RCC and how to combat therapeutic resistance. Cancers, including RCC, rely on sustained replicative potential. The cyclin-dependent kinases CDK4 and CDK6 are involved in cell-cycle regulation with additional roles in metabolism, immunogenicity and antitumour immune response. Inhibitors of CDK4 and CDK6 are now commonly used as approved and investigative treatments in breast cancer, as well as several other tumours. Furthermore, CDK4/6 inhibitors have been shown to work synergistically with other kinase inhibitors, including mTOR inhibitors, as well as with immune checkpoint inhibitors in preclinical cancer models. The effect of CDK4/6 inhibitors in kidney cancer is relatively understudied compared with other cancers, but the preclinical studies available are promising. Collectively, growing evidence suggests that targeting CDK4 and CDK6 in kidney cancer, alone and in combination with current therapeutics including mTOR and immune checkpoint inhibitors, might have therapeutic benefit and should be further explored., (© 2022. Springer Nature Limited.)
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- 2022
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18. Hsp90 chaperone code and the tumor suppressor VHL cooperatively regulate the mitotic checkpoint.
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Woodford MR, Backe SJ, Wengert LA, Dunn DM, Bourboulia D, and Mollapour M
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- Humans, M Phase Cell Cycle Checkpoints genetics, Mitosis genetics, Molecular Chaperones genetics, Phosphorylation, Protein Binding, Proteolysis, Signal Transduction genetics, Cell Cycle Proteins genetics, Chaperonins genetics, HSP90 Heat-Shock Proteins genetics, Protein Serine-Threonine Kinases genetics, Protein-Tyrosine Kinases genetics, Von Hippel-Lindau Tumor Suppressor Protein genetics
- Abstract
Heat shock protein-90 (Hsp90) is an essential molecular chaperone in eukaryotes that plays a vital role in protecting and maintaining the functional integrity of deregulated signaling proteins in tumors. We have previously reported that the stability and activity of the mitotic checkpoint kinase Mps1 depend on Hsp90. In turn, Mps1-mediated phosphorylation Hsp90 regulates its chaperone function and is essential for the mitotic arrest. Cdc14-assisted dephosphorylation of Hsp90 is vital for the mitotic exit. Post-translational regulation of Hsp90 function is also known as the Hsp90 "Chaperone Code." Here, we demonstrate that only the active Mps1 is ubiquitinated on K86, K827, and K848 by the tumor suppressor von Hippel-Lindau (VHL) containing E3 enzyme, in a prolyl hydroxylation-independent manner and degraded in the proteasome. Furthermore, we show that this process regulates cell exit from the mitotic checkpoint. Collectively, our data demonstrates an interplay between the Hsp90 chaperone and VHL degradation machinery in regulating mitosis., (© 2021. The Author(s).)
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- 2021
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19. The tumor suppressor folliculin inhibits lactate dehydrogenase A and regulates the Warburg effect.
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Woodford MR, Baker-Williams AJ, Sager RA, Backe SJ, Blanden AR, Hashmi F, Kancherla P, Gori A, Loiselle DR, Castelli M, Serapian SA, Colombo G, Haystead TA, Jensen SM, Stetler-Stevenson WG, Loh SN, Schmidt LS, Linehan WM, Bah A, Bourboulia D, Bratslavsky G, and Mollapour M
- Subjects
- Catalytic Domain physiology, Cell Line, Tumor, Cell Proliferation, Gene Expression Regulation, Neoplastic genetics, HEK293 Cells, Humans, Lactate Dehydrogenase 5 metabolism, Signal Transduction, Glycolysis physiology, Lactate Dehydrogenase 5 antagonists & inhibitors, Neoplasms metabolism, Proto-Oncogene Proteins metabolism, Tumor Suppressor Proteins metabolism
- Abstract
Aerobic glycolysis in cancer cells, also known as the 'Warburg effect', is driven by hyperactivity of lactate dehydrogenase A (LDHA). LDHA is thought to be a substrate-regulated enzyme, but it is unclear whether a dedicated intracellular protein also regulates its activity. Here, we identify the human tumor suppressor folliculin (FLCN) as a binding partner and uncompetitive inhibitor of LDHA. A flexible loop within the amino terminus of FLCN controls movement of the LDHA active-site loop, tightly regulating its enzyme activity and, consequently, metabolic homeostasis in normal cells. Cancer cells that experience the Warburg effect show FLCN dissociation from LDHA. Treatment of these cells with a decapeptide derived from the FLCN loop region causes cell death. Our data suggest that the glycolytic shift of cancer cells is the result of FLCN inactivation or dissociation from LDHA. Together, FLCN-mediated inhibition of LDHA provides a new paradigm for the regulation of glycolysis., (© 2021. The Author(s), under exclusive licence to Springer Nature America, Inc.)
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- 2021
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20. MMPs, tyrosine kinase signaling and extracellular matrix proteolysis in kidney cancer.
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Hashmi F, Mollapour M, Bratslavsky G, and Bourboulia D
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- Humans, Signal Transduction, Carcinoma, Renal Cell metabolism, Carcinoma, Renal Cell pathology, Extracellular Matrix metabolism, Kidney Neoplasms metabolism, Kidney Neoplasms pathology, Matrix Metalloproteinases metabolism, Protein-Tyrosine Kinases metabolism, Proteolysis
- Abstract
Patients diagnosed with metastatic renal cell carcinoma (RCC) have ∼12% chance for 5-year survival. The integrity of the extracellular matrix (ECM) that surrounds tumor cells influences their behavior and, when disturbed, it could facilitate local invasion and spread of tumor cells to distant sites. The interplay between von Hippel-Lindau/hypoxia inducible factor signaling axis and activated kinase networks results in aberrant ECM and tumor progression. Matrix metalloproteinases (MMPs) are proteolytic enzymes implicated in ECM remodeling, tumor angiogenesis, and immune cell infiltration. Understanding the cross-talk between kinase signaling and ECM proteolysis in RCC could provide insights into developing drugs that interfere specifically with the process of invasion. In this review, we discuss changes in the MMPs/ECM axis in RCC, prominent kinase signaling pathways implicated in MMPs induction, and comment on emerging extracellular regulatory networks that modulate MMPs activity., (Copyright © 2020 Elsevier Inc. All rights reserved.)
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- 2021
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21. Comprehensive genomic profiling of metastatic collecting duct carcinoma, renal medullary carcinoma, and clear cell renal cell carcinoma.
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Bratslavsky G, Gleicher S, Jacob JM, Sanford TH, Shapiro O, Bourboulia D, Gay LM, Andrea Elvin J, Vergilio JA, Suh J, Ramkissoon S, Severson EA, Killian JK, Schrock AB, Chung JH, Miller VA, Mollapour M, and Ross JS
- Subjects
- Adult, Carcinoma, Medullary secondary, Carcinoma, Renal Cell secondary, Female, Genomics, Humans, Kidney Neoplasms pathology, Male, Middle Aged, Mutation, Carcinoma, Medullary genetics, Carcinoma, Renal Cell genetics, Gene Expression Profiling, Kidney Neoplasms genetics
- Abstract
Introduction and Objective: Unlike clear cell renal cell carcinoma (CCRCC), collecting duct carcinoma (CDC) and renal medullary carcinoma (RMC) are rare tumors that progress rapidly and appear resistant to current systemic therapies. We queried comprehensive genomic profiling to uncover opportunities for targeted therapy and immunotherapy., Material and Methods: DNA was extracted from 40 microns of formalin-fixed, paraffin-embedded specimen from relapsed, mCDC (n = 46), mRMC (n = 24), and refractory and metastatic (m) mCCRCC (n = 626). Comprehensive genomic profiling was performed, and Tumor mutational burden (TMB) and microsatellite instability (MSI) were calculated. We analyzed all classes of genomic alterations., Results: mCDC had 1.7 versus 2.7 genomic alterations/tumor in mCCRCC ( = 0.04). Mutations in VHL (P < 0.0001) and TSC1 (P = 0.04) were more frequent in mCCRCC. SMARCB1 (P < 0.0001), NF2 (P = 0.0007), RB1 (P = 0.02) and RET (P = 0.0003) alterations were more frequent in mCDC versus mCCRCC. No VHL alterations in mRMC and mCDC were identified. SMARCB1 genomic alterations were significantly more frequent in mRMC than mCDC (P = 0.0002), but were the most common alterations in both subtypes. Mutations to EGFR, RET, NF2, and TSC2 were more frequently identified in mCDC versus mRMC. The median TMB and MSI-High status was low with <1% of mCCRC, mCDC, and mRMC having ≥ 20 mut/Mb., Conclusion: Genomic alteration patterns in mCDC and mRMC differ significantly from mCCRCC. Targeted therapies for mCDC and mRMC appear limited with rare opportunities to target alterations in receptor tyrosine kinase and MTOR pathways. Similarly, TMB and absence of MSI-High status in mCDC and mRMC suggest resistance to immunotherapies., (Copyright © 2020. Published by Elsevier Inc.)
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- 2021
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22. The Role of Heat Shock Protein-90 in the Pathogenesis of Birt-Hogg-Dubé and Tuberous Sclerosis Complex Syndromes.
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Woodford MR, Backe SJ, Sager RA, Bourboulia D, Bratslavsky G, and Mollapour M
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- Angiomyolipoma etiology, Carcinoma, Renal Cell etiology, Humans, Kidney Neoplasms etiology, Birt-Hogg-Dube Syndrome etiology, HSP90 Heat-Shock Proteins physiology, Tuberous Sclerosis etiology
- Abstract
Birt-Hogg-Dubé (BHD) and tuberous sclerosis (TS) syndromes share many clinical features. These two diseases display distinct histologic subtypes of renal tumors: chromophobe renal cell carcinoma and renal angiomyolipoma, respectively. Early work suggested a role for mTOR dysregulation in the pathogenesis of these two diseases, however their detailed molecular link remains elusive. Interestingly, a growing number of case reports describe renal angiomyolipoma in BHD patients, suggesting a common molecular origin. The BHD-associated proteins FNIP1/2 and the TS protein Tsc1 were recently identified as regulators of the molecular chaperone Hsp90. Dysregulation of Hsp90 activity has previously been reported to support tumorigenesis, providing a potential explanation for the overlapping phenotypic manifestations in these two hereditary syndromes., (Copyright © 2020 Elsevier Inc. All rights reserved.)
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- 2021
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23. The 2021 FASEB Virtual Catalyst Conference on Extracellular and Organismal Proteostasis in Health and Disease, February 3-4, 2021.
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Lior C, Hodge F, De-Souza EA, Bourboulia D, Calderwood SK, David D, Allan Drummond D, Edkins A, Morimoto RI, Prahlad V, Rechavi O, Sistonen L, Wilson M, Wiseman RL, Zanetti M, Taylor R, Scherz-Shouval R, and van Oosten-Hawle P
- Subjects
- Animals, Congresses as Topic, Humans, Proteostasis Deficiencies immunology, Immunity, Innate, Proteostasis, Proteostasis Deficiencies pathology, Stress, Physiological
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- 2021
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24. Decrypting the chaperone code.
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Truman AW, Bourboulia D, and Mollapour M
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- Animals, Humans, HSP70 Heat-Shock Proteins metabolism, HSP90 Heat-Shock Proteins metabolism, Heat Shock Transcription Factors metabolism
- Abstract
Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article.
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- 2021
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25. Chemical Perturbation of Oncogenic Protein Folding: from the Prediction of Locally Unstable Structures to the Design of Disruptors of Hsp90-Client Interactions.
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Paladino A, Woodford MR, Backe SJ, Sager RA, Kancherla P, Daneshvar MA, Chen VZ, Bourboulia D, Ahanin EF, Prodromou C, Bergamaschi G, Strada A, Cretich M, Gori A, Veronesi M, Bandiera T, Vanna R, Bratslavsky G, Serapian SA, Mollapour M, and Colombo G
- Subjects
- Carcinogens metabolism, Cell Cycle Proteins metabolism, HSP90 Heat-Shock Proteins metabolism, Humans, Protein Folding, Carcinogens chemistry, Cell Cycle Proteins chemistry, Chaperonins chemistry, HSP90 Heat-Shock Proteins chemistry, Molecular Chaperones chemistry
- Abstract
Protein folding quality control in cells requires the activity of a class of proteins known as molecular chaperones. Heat shock protein-90 (Hsp90), a multidomain ATP driven molecular machine, is a prime representative of this family of proteins. Interactions between Hsp90, its co-chaperones, and client proteins have been shown to be important in facilitating the correct folding and activation of clients. Hsp90 levels and functions are elevated in tumor cells. Here, we computationally predict the regions on the native structures of clients c-Abl, c-Src, Cdk4, B-Raf and Glucocorticoid Receptor, that have the highest probability of undergoing local unfolding, despite being ordered in their native structures. Such regions represent potential ideal interaction points with the Hsp90-system. We synthesize mimics spanning these regions and confirm their interaction with partners of the Hsp90 complex (Hsp90, Cdc37 and Aha1) by Nuclear Magnetic Resonance (NMR). Designed mimics selectively disrupt the association of their respective clients with the Hsp90 machinery, leaving unrelated clients unperturbed and causing apoptosis in cancer cells. Overall, selective targeting of Hsp90 protein-protein interactions is achieved without causing indiscriminate degradation of all clients, setting the stage for the development of therapeutics based on specific chaperone:client perturbation., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2020
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26. Mutation of the co-chaperone Tsc1 in bladder cancer diminishes Hsp90 acetylation and reduces drug sensitivity and selectivity.
- Author
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Woodford MR, Hughes M, Sager RA, Backe SJ, Baker-Williams AJ, Bratslavsky MS, Jacob JM, Shapiro O, Wong M, Bratslavsky G, Bourboulia D, and Mollapour M
- Abstract
The molecular chaperone Heat shock protein 90 (Hsp90) is essential for the folding, stability, and activity of several drivers of oncogenesis. Hsp90 inhibitors are currently under clinical evaluation for cancer treatment, however their efficacy is limited by lack of biomarkers to optimize patient selection. We have recently identified the tumor suppressor tuberous sclerosis complex 1 (Tsc1) as a new co-chaperone of Hsp90 that affects Hsp90 binding to its inhibitors. Highly variable mutations of TSC1 have been previously identified in bladder cancer and correlate with sensitivity to the Hsp90 inhibitors. Here we showed loss of TSC1 leads to hypoacetylation of Hsp90-K407/K419 and subsequent decreased binding to the Hsp90 inhibitor ganetespib. Pharmacologic inhibition of histone deacetylases (HDACs) restores acetylation of Hsp90 and sensitizes Tsc1-mutant bladder cancer cells to ganetespib, resulting in apoptosis. Our findings suggest that TSC1 status may predict response to Hsp90 inhibitors in patients with bladder cancer, and co-targeting HDACs can sensitize tumors with Tsc1 mutations to Hsp90 inhibitors., Competing Interests: CONFLICTS OF INTEREST The authors declare no competing financial interests., (Copyright: © 2019 Woodford et al.)
- Published
- 2019
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27. Co-chaperones TIMP2 and AHA1 Competitively Regulate Extracellular HSP90:Client MMP2 Activity and Matrix Proteolysis.
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Baker-Williams AJ, Hashmi F, Budzyński MA, Woodford MR, Gleicher S, Himanen SV, Makedon AM, Friedman D, Cortes S, Namek S, Stetler-Stevenson WG, Bratslavsky G, Bah A, Mollapour M, Sistonen L, and Bourboulia D
- Subjects
- Animals, Cells, Cultured, Fibroblasts cytology, Fibroblasts metabolism, HEK293 Cells, HSP90 Heat-Shock Proteins genetics, Humans, Matrix Metalloproteinase 2 genetics, Mice, Mice, Knockout, Molecular Chaperones genetics, Tissue Inhibitor of Metalloproteinase-2 genetics, Extracellular Matrix metabolism, HSP90 Heat-Shock Proteins metabolism, Matrix Metalloproteinase 2 metabolism, Molecular Chaperones metabolism, Molecular Chaperones physiology, Proteolysis, Tissue Inhibitor of Metalloproteinase-2 metabolism
- Abstract
The extracellular molecular chaperone heat shock protein 90 (eHSP90) stabilizes protease client the matrix metalloproteinase 2 (MMP2), leading to tumor cell invasion. Although co-chaperones are critical modulators of intracellular HSP90:client function, how the eHSP90:MMP2 complex is regulated remains speculative. Here, we report that the tissue inhibitor of metalloproteinases-2 (TIMP2) is a stress-inducible extracellular co-chaperone that binds to eHSP90, increases eHSP90 binding to ATP, and inhibits its ATPase activity. In addition to disrupting the eHSP90:MMP2 complex and terminally inactivating MMP2, TIMP2 loads the client to eHSP90, keeping the protease in a transient inhibitory state. Secreted activating co-chaperone AHA1 displaces TIMP2 from the complex, providing a "reactivating" mechanism for MMP2. Gene knockout or blocking antibodies targeting TIMP2 and AHA1 released by HT1080 cancer cells modify their gelatinolytic activity. Our data suggest that TIMP2 and AHA1 co-chaperones function as a molecular switch that determines the inhibition and reactivation of the eHSP90 client protein MMP2., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
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28. Post-translational Regulation of FNIP1 Creates a Rheostat for the Molecular Chaperone Hsp90.
- Author
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Sager RA, Woodford MR, Backe SJ, Makedon AM, Baker-Williams AJ, DiGregorio BT, Loiselle DR, Haystead TA, Zachara NE, Prodromou C, Bourboulia D, Schmidt LS, Linehan WM, Bratslavsky G, and Mollapour M
- Subjects
- Casein Kinase II metabolism, Glycosylation, HEK293 Cells, Humans, Models, Biological, Nuclear Proteins metabolism, Phosphoprotein Phosphatases metabolism, Phosphorylation, Phosphoserine metabolism, Proteasome Endopeptidase Complex metabolism, Protein Binding, Ubiquitination, Carrier Proteins metabolism, HSP90 Heat-Shock Proteins metabolism, Protein Processing, Post-Translational
- Abstract
The molecular chaperone Hsp90 stabilizes and activates client proteins. Co-chaperones and post-translational modifications tightly regulate Hsp90 function and consequently lead to activation of clients. However, it is unclear whether this process occurs abruptly or gradually in the cellular context. We show that casein kinase-2 phosphorylation of the co-chaperone folliculin-interacting protein 1 (FNIP1) on priming serine-938 and subsequent relay phosphorylation on serine-939, 941, 946, and 948 promotes its gradual interaction with Hsp90. This leads to incremental inhibition of Hsp90 ATPase activity and gradual activation of both kinase and non-kinase clients. We further demonstrate that serine/threonine protein phosphatase 5 (PP5) dephosphorylates FNIP1, allowing the addition of O-GlcNAc (O-linked N-acetylglucosamine) to the priming serine-938. This process antagonizes phosphorylation of FNIP1, preventing its interaction with Hsp90, and consequently promotes FNIP1 lysine-1119 ubiquitination and proteasomal degradation. These findings provide a mechanism for gradual activation of the client proteins through intricate crosstalk of post-translational modifications of the co-chaperone FNIP1., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
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29. Extracellular Phosphorylation of TIMP-2 by Secreted c-Src Tyrosine Kinase Controls MMP-2 Activity.
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Sánchez-Pozo J, Baker-Williams AJ, Woodford MR, Bullard R, Wei B, Mollapour M, Stetler-Stevenson WG, Bratslavsky G, and Bourboulia D
- Abstract
The tissue inhibitor of metalloproteinases 2 (TIMP-2) is a specific endogenous inhibitor of matrix metalloproteinase 2 (MMP-2), which is a key enzyme that degrades the extracellular matrix and promotes tumor cell invasion. Although the TIMP-2:MMP-2 complex controls proteolysis, the signaling mechanism by which the two proteins associate in the extracellular space remains unidentified. Here we report that TIMP-2 is phosphorylated outside the cell by secreted c-Src tyrosine kinase. As a consequence, phosphorylation at Y90 significantly enhances TIMP-2 potency as an MMP-2 inhibitor and weakens the catalytic action of the active enzyme. TIMP-2 phosphorylation also appears to be essential for its interaction with the latent enzyme proMMP-2 in vivo. Absence of the kinase or non-phosphorylatable Y90 abolishes TIMP-2 binding to the latent enzyme, ultimately hampering proMMP-2 activation. Together, TIMP-2 phosphorylation by secreted c-Src represents a critical extracellular regulatory mechanism that controls the proteolytic function of MMP-2., (Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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30. Detection and Analysis of Extracellular Hsp90 (eHsp90).
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Cortes S, Baker-Williams AJ, Mollapour M, and Bourboulia D
- Subjects
- HEK293 Cells, Humans, Blotting, Western methods, Extracellular Space metabolism, HSP90 Heat-Shock Proteins analysis, Immunoprecipitation methods
- Abstract
Heat Shock Protein 90 (Hsp90) is a ubiquitous molecular chaperone that comprises about 1-3% of the total cellular protein. Over the last decade, Hsp90 has been detected and studied in the extracellular space (extracellular or eHsp90) of normal and neoplastic cells. Once outside the cell, eHsp90 has been shown to interact with extracellular client proteins and promote their stabilization and function. Cell conditioned media are routinely collected to detect and quantify eHsp90, and determine its interactions with extracellular clients. Finally, targeting specifically the eHsp90 with pharmacologic inhibitors or antibodies that are unable to cross the plasma membrane has been beneficial in inhibiting tumor cell motility and invasion.
- Published
- 2018
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31. Tumor suppressor Tsc1 is a new Hsp90 co-chaperone that facilitates folding of kinase and non-kinase clients.
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Woodford MR, Sager RA, Marris E, Dunn DM, Blanden AR, Murphy RL, Rensing N, Shapiro O, Panaretou B, Prodromou C, Loh SN, Gutmann DH, Bourboulia D, Bratslavsky G, Wong M, and Mollapour M
- Subjects
- HEK293 Cells, HSP90 Heat-Shock Proteins genetics, Humans, Phosphorylation, Phosphotransferases metabolism, Proteasome Endopeptidase Complex, Protein Folding, Proteolysis, Tuberous Sclerosis Complex 1 Protein, Tuberous Sclerosis Complex 2 Protein, Tumor Suppressor Proteins genetics, Ubiquitination, HSP90 Heat-Shock Proteins metabolism, Tumor Suppressor Proteins metabolism
- Abstract
The tumor suppressors Tsc1 and Tsc2 form the tuberous sclerosis complex (TSC), a regulator of mTOR activity. Tsc1 stabilizes Tsc2; however, the precise mechanism involved remains elusive. The molecular chaperone heat-shock protein 90 (Hsp90) is an essential component of the cellular homeostatic machinery in eukaryotes. Here, we show that Tsc1 is a new co-chaperone for Hsp90 that inhibits its ATPase activity. The C-terminal domain of Tsc1 (998-1,164 aa) forms a homodimer and binds to both protomers of the Hsp90 middle domain. This ensures inhibition of both subunits of the Hsp90 dimer and prevents the activating co-chaperone Aha1 from binding the middle domain of Hsp90. Conversely, phosphorylation of Aha1-Y223 increases its affinity for Hsp90 and displaces Tsc1, thereby providing a mechanism for equilibrium between binding of these two co-chaperones to Hsp90. Our findings establish an active role for Tsc1 as a facilitator of Hsp90-mediated folding of kinase and non-kinase clients-including Tsc2-thereby preventing their ubiquitination and proteasomal degradation., (© 2017 The Authors. Published under the terms of the CC BY 4.0 license.)
- Published
- 2017
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32. Phosphorylation and Ubiquitination Regulate Protein Phosphatase 5 Activity and Its Prosurvival Role in Kidney Cancer.
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Dushukyan N, Dunn DM, Sager RA, Woodford MR, Loiselle DR, Daneshvar M, Baker-Williams AJ, Chisholm JD, Truman AW, Vaughan CK, Haystead TA, Bratslavsky G, Bourboulia D, and Mollapour M
- Subjects
- Carcinoma, Renal Cell pathology, Cell Line, Tumor, Glycoproteins genetics, Humans, Kidney Neoplasms pathology, Phosphorylation, Von Hippel-Lindau Tumor Suppressor Protein genetics, Von Hippel-Lindau Tumor Suppressor Protein metabolism, Apoptosis, Carcinoma, Renal Cell metabolism, Glycoproteins metabolism, Kidney Neoplasms metabolism, Ubiquitination
- Abstract
The serine/threonine protein phosphatase 5 (PP5) regulates multiple cellular signaling networks. A number of cellular factors, including heat shock protein 90 (Hsp90), promote the activation of PP5. However, it is unclear whether post-translational modifications also influence PP5 phosphatase activity. Here, we show an "on/off switch" mechanism for PP5 regulation. The casein kinase 1δ (CK1δ) phosphorylates T362 in the catalytic domain of PP5, which activates and enhances phosphatase activity independent of Hsp90. Overexpression of the phosphomimetic T362E-PP5 mutant hyper-dephosphorylates substrates such as the co-chaperone Cdc37 and glucocorticoid receptor in cells. Our proteomic approach revealed that the tumor suppressor von Hippel-Lindau protein (VHL) interacts with and ubiquitinates K185/K199-PP5 for proteasomal degradation in a hypoxia- and prolyl-hydroxylation-independent manner. Finally, VHL-deficient clear cell renal cell carcinoma (ccRCC) cell lines and patient tumors exhibit elevated PP5 levels. Downregulation of PP5 causes ccRCC cells to undergo apoptosis, suggesting a prosurvival role for PP5 in kidney cancer., (Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
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33. Structural and functional basis of protein phosphatase 5 substrate specificity.
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Oberoi J, Dunn DM, Woodford MR, Mariotti L, Schulman J, Bourboulia D, Mollapour M, and Vaughan CK
- Subjects
- Catalytic Domain, Cell Cycle Proteins chemistry, Chaperonins chemistry, Crystallization, HSP90 Heat-Shock Proteins physiology, Nuclear Proteins physiology, Phosphoprotein Phosphatases physiology, Phosphorylation, Substrate Specificity, Nuclear Proteins chemistry, Phosphoprotein Phosphatases chemistry
- Abstract
The serine/threonine phosphatase protein phosphatase 5 (PP5) regulates hormone- and stress-induced cellular signaling by association with the molecular chaperone heat shock protein 90 (Hsp90). PP5-mediated dephosphorylation of the cochaperone Cdc37 is essential for activation of Hsp90-dependent kinases. However, the details of this mechanism remain unknown. We determined the crystal structure of a Cdc37 phosphomimetic peptide bound to the catalytic domain of PP5. The structure reveals PP5 utilization of conserved elements of phosphoprotein phosphatase (PPP) structure to bind substrate and provides a template for many PPP-substrate interactions. Our data show that, despite a highly conserved structure, elements of substrate specificity are determined within the phosphatase catalytic domain itself. Structure-based mutations in vivo reveal that PP5-mediated dephosphorylation is required for kinase and steroid hormone receptor release from the chaperone complex. Finally, our data show that hyper- or hypoactivity of PP5 mutants increases Hsp90 binding to its inhibitor, suggesting a mechanism to enhance the efficacy of Hsp90 inhibitors by regulation of PP5 activity in tumors.
- Published
- 2016
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34. The FNIP co-chaperones decelerate the Hsp90 chaperone cycle and enhance drug binding.
- Author
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Woodford MR, Dunn DM, Blanden AR, Capriotti D, Loiselle D, Prodromou C, Panaretou B, Hughes PF, Smith A, Ackerman W, Haystead TA, Loh SN, Bourboulia D, Schmidt LS, Marston Linehan W, Bratslavsky G, and Mollapour M
- Subjects
- Antineoplastic Agents metabolism, Carcinoma, Renal Cell drug therapy, Carrier Proteins genetics, Cell Line, Tumor, Gene Expression Regulation, Neoplastic, HSP90 Heat-Shock Proteins antagonists & inhibitors, Humans, Intracellular Signaling Peptides and Proteins, Molecular Chaperones physiology, Proto-Oncogene Proteins genetics, Tumor Suppressor Proteins genetics, Antineoplastic Agents pharmacology, Carrier Proteins metabolism, HSP90 Heat-Shock Proteins metabolism, Proto-Oncogene Proteins metabolism, Tumor Suppressor Proteins metabolism
- Abstract
Heat shock protein-90 (Hsp90) is an essential molecular chaperone in eukaryotes involved in maintaining the stability and activity of numerous signalling proteins, also known as clients. Hsp90 ATPase activity is essential for its chaperone function and it is regulated by co-chaperones. Here we show that the tumour suppressor FLCN is an Hsp90 client protein and its binding partners FNIP1/FNIP2 function as co-chaperones. FNIPs decelerate the chaperone cycle, facilitating FLCN interaction with Hsp90, consequently ensuring FLCN stability. FNIPs compete with the activating co-chaperone Aha1 for binding to Hsp90, thereby providing a reciprocal regulatory mechanism for chaperoning of client proteins. Lastly, downregulation of FNIPs desensitizes cancer cells to Hsp90 inhibitors, whereas FNIPs overexpression in renal tumours compared with adjacent normal tissues correlates with enhanced binding of Hsp90 to its inhibitors. Our findings suggest that FNIPs expression can potentially serve as a predictive indicator of tumour response to Hsp90 inhibitors.
- Published
- 2016
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35. Mps1 Mediated Phosphorylation of Hsp90 Confers Renal Cell Carcinoma Sensitivity and Selectivity to Hsp90 Inhibitors.
- Author
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Woodford MR, Truman AW, Dunn DM, Jensen SM, Cotran R, Bullard R, Abouelleil M, Beebe K, Wolfgeher D, Wierzbicki S, Post DE, Caza T, Tsutsumi S, Panaretou B, Kron SJ, Trepel JB, Landas S, Prodromou C, Shapiro O, Stetler-Stevenson WG, Bourboulia D, Neckers L, Bratslavsky G, and Mollapour M
- Subjects
- Amino Acid Sequence, Antineoplastic Agents pharmacology, Cell Cycle Proteins metabolism, Enzyme Inhibitors pharmacology, HSP90 Heat-Shock Proteins antagonists & inhibitors, Humans, Molecular Sequence Data, Phosphorylation, Protein Binding, Proteolysis, Saccharomyces cerevisiae enzymology, Saccharomyces cerevisiae metabolism, Carcinoma, Renal Cell metabolism, HSP90 Heat-Shock Proteins metabolism, Kidney Neoplasms metabolism, Protein Processing, Post-Translational, Protein Serine-Threonine Kinases metabolism, Saccharomyces cerevisiae Proteins metabolism
- Abstract
The molecular chaperone Hsp90 protects deregulated signaling proteins that are vital for tumor growth and survival. Tumors generally display sensitivity and selectivity toward Hsp90 inhibitors; however, the molecular mechanism underlying this phenotype remains undefined. We report that the mitotic checkpoint kinase Mps1 phosphorylates a conserved threonine residue in the amino-domain of Hsp90. This, in turn, regulates chaperone function by reducing Hsp90 ATPase activity while fostering Hsp90 association with kinase clients, including Mps1. Phosphorylation of Hsp90 is also essential for the mitotic checkpoint because it confers Mps1 stability and activity. We identified Cdc14 as the phosphatase that dephosphorylates Hsp90 and disrupts its interaction with Mps1. This causes Mps1 degradation, thus providing a mechanism for its inactivation. Finally, Hsp90 phosphorylation sensitizes cells to its inhibitors, and elevated Mps1 levels confer renal cell carcinoma selectivity to Hsp90 drugs. Mps1 expression level can potentially serve as a predictive indicator of tumor response to Hsp90 inhibitors., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
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36. The dynamic interactome of human Aha1 upon Y223 phosphorylation.
- Author
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Wolfgeher D, Dunn DM, Woodford MR, Bourboulia D, Bratslavsky G, Mollapour M, Kron SJ, and Truman AW
- Abstract
Heat Shock Protein 90 (Hsp90) is an essential chaperone that supports the function of a wide range of signaling molecules. Hsp90 binds to a suite of co-chaperone proteins that regulate Hsp90 function through alteration of intrinsic ATPase activity. Several studies have determined Aha1 to be an important co-chaperone whose binding to Hsp90 is modulated by phosphorylation, acetylation and SUMOylation of Hsp90 [1], [2]. In this study, we applied quantitative affinity-purification mass spectrometry (AP-MS) proteomics to understand how phosphorylation of hAha1 at Y223 altered global client/co-chaperone interaction [3]. Specifically, we characterized and compared the interactomes of Aha1-Y223F (phospho-mutant form) and Aha1-Y223E (phospho-mimic form). We identified 99 statistically significant interactors of hAha1, a high proportion of which (84%) demonstrated preferential binding to the phospho-mimic form of hAha1. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium (http://proteomecentral.proteomexchange.org) via the PRIDE partner repository [4] with the dataset identifier PXD001737.
- Published
- 2015
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37. c-Abl Mediated Tyrosine Phosphorylation of Aha1 Activates Its Co-chaperone Function in Cancer Cells.
- Author
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Dunn DM, Woodford MR, Truman AW, Jensen SM, Schulman J, Caza T, Remillard TC, Loiselle D, Wolfgeher D, Blagg BS, Franco L, Haystead TA, Daturpalli S, Mayer MP, Trepel JB, Morgan RM, Prodromou C, Kron SJ, Panaretou B, Stetler-Stevenson WG, Landas SK, Neckers L, Bratslavsky G, Bourboulia D, and Mollapour M
- Subjects
- HEK293 Cells, HSP90 Heat-Shock Proteins genetics, Humans, Immunoprecipitation, Models, Biological, Molecular Chaperones genetics, Phosphorylation, Proto-Oncogene Proteins c-abl genetics, HSP90 Heat-Shock Proteins metabolism, Molecular Chaperones metabolism, Proteasome Endopeptidase Complex metabolism, Proto-Oncogene Proteins c-abl metabolism
- Abstract
The ability of Heat Shock Protein 90 (Hsp90) to hydrolyze ATP is essential for its chaperone function. The co-chaperone Aha1 stimulates Hsp90 ATPase activity, tailoring the chaperone function to specific "client" proteins. The intracellular signaling mechanisms directly regulating Aha1 association with Hsp90 remain unknown. Here, we show that c-Abl kinase phosphorylates Y223 in human Aha1 (hAha1), promoting its interaction with Hsp90. This, consequently, results in an increased Hsp90 ATPase activity, enhances Hsp90 interaction with kinase clients, and compromises the chaperoning of non-kinase clients such as glucocorticoid receptor and CFTR. Suggesting a regulatory paradigm, we also find that Y223 phosphorylation leads to ubiquitination and degradation of hAha1 in the proteasome. Finally, pharmacologic inhibition of c-Abl prevents hAha1 interaction with Hsp90, thereby hypersensitizing cancer cells to Hsp90 inhibitors both in vitro and ex vivo., (Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2015
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38. Targeting Hsp90 in urothelial carcinoma.
- Author
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Chehab M, Caza T, Skotnicki K, Landas S, Bratslavsky G, Mollapour M, and Bourboulia D
- Subjects
- Angiogenesis Inhibitors therapeutic use, Antineoplastic Agents therapeutic use, Apoptosis, BCG Vaccine therapeutic use, Carcinoma, Transitional Cell epidemiology, Carcinoma, Transitional Cell metabolism, Carcinoma, Transitional Cell pathology, Cell Cycle drug effects, Cell Division, Cell Transformation, Neoplastic, Chemoradiotherapy, Chemotherapy, Adjuvant, Clinical Trials as Topic, Combined Modality Therapy, Cystectomy, Drug Resistance, Neoplasm, Drugs, Investigational therapeutic use, HSP90 Heat-Shock Proteins chemistry, HSP90 Heat-Shock Proteins physiology, Histone Code drug effects, Humans, Models, Biological, Muscle, Smooth pathology, Neoplasm Invasiveness, Neoplasm Proteins physiology, Protein Kinase Inhibitors therapeutic use, Signal Transduction drug effects, Transcription, Genetic drug effects, Urologic Neoplasms epidemiology, Urologic Neoplasms metabolism, Urologic Neoplasms pathology, Carcinoma, Transitional Cell therapy, HSP90 Heat-Shock Proteins antagonists & inhibitors, Molecular Targeted Therapy, Neoplasm Proteins antagonists & inhibitors, Urologic Neoplasms therapy
- Abstract
Urothelial carcinoma, or transitional cell carcinoma, is the most common urologic malignancy that carries significant morbidity, mortality, recurrence risk and associated health care costs. Despite use of current chemotherapies and immunotherapies, long-term remission in patients with muscle-invasive or metastatic disease remains low, and disease recurrence is common. The molecular chaperone Heat Shock Protein-90 (Hsp90) may offer an ideal treatment target, as it is a critical signaling hub in urothelial carcinoma pathogenesis and potentiates chemoradiation. Preclinical testing with Hsp90 inhibitors has demonstrated reduced proliferation, enhanced apoptosis and synergism with chemotherapies and radiation. Despite promising preclinical data, clinical trials utilizing Hsp90 inhibitors for other malignancies had modest efficacy. Therefore, we propose that Hsp90 inhibition would best serve as an adjuvant treatment in advanced muscle-invasive or metastatic bladder cancers to potentiate other therapies. An overview of bladder cancer biology, current treatments, molecular targeted therapies, and the role for Hsp90 inhibitors in the treatment of urothelial carcinoma is the focus of this review.
- Published
- 2015
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39. Molecular mechanisms of tissue inhibitor of metalloproteinase 2 in the tumor microenvironment.
- Author
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Remillard TC, Bratslavsky G, Jensen-Taubman S, Stetler-Stevenson WG, and Bourboulia D
- Abstract
There has been a recent paradigm shift in the way we target cancer, drawing a greater focus on the role of the tumor microenvironment (TME) in cancer development, progression and metastasis. Within the TME, there is a crosstalk in signaling and communication between the malignant cells and the surrounding extracellular matrix. Matrix metalloproteinases (MMPs) are zinc-dependent endoproteases that have the ability to degrade the matrix surrounding a tumor and mediate tumor growth, angiogenesis and metastatic disease. Their endogenous inhibitors, the Tissue Inhibitors of Metalloproteinases (TIMPs), primarily function to prevent degradation of the ECM via inhibition of MMPs. However, recent studies demonstrate that TIMP family members also possess MMP-independent functions. One TIMP member in particular, TIMP-2, has many distinct properties and functions, that occur independent of MMP inhibition, including the inhibition of tumor growth and reduction of angiogenesis through decreased endothelial cell proliferation and migration. The MMP-independent molecular mechanisms and signaling pathways elicited by TIMP-2 in the TME are described in this review.
- Published
- 2014
40. Asymmetric Hsp90 N domain SUMOylation recruits Aha1 and ATP-competitive inhibitors.
- Author
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Mollapour M, Bourboulia D, Beebe K, Woodford MR, Polier S, Hoang A, Chelluri R, Li Y, Guo A, Lee MJ, Fotooh-Abadi E, Khan S, Prince T, Miyajima N, Yoshida S, Tsutsumi S, Xu W, Panaretou B, Stetler-Stevenson WG, Bratslavsky G, Trepel JB, Prodromou C, and Neckers L
- Subjects
- HSP90 Heat-Shock Proteins chemistry, HSP90 Heat-Shock Proteins physiology, Humans, Protein Structure, Tertiary, Sumoylation, Adenosine Triphosphate metabolism, Chaperonins metabolism, HSP90 Heat-Shock Proteins metabolism, Saccharomyces cerevisiae metabolism, Saccharomyces cerevisiae Proteins metabolism
- Abstract
The stability and activity of numerous signaling proteins in both normal and cancer cells depends on the dimeric molecular chaperone heat shock protein 90 (Hsp90). Hsp90's function is coupled to ATP binding and hydrolysis and requires a series of conformational changes that are regulated by cochaperones and numerous posttranslational modifications (PTMs). SUMOylation is one of the least-understood Hsp90 PTMs. Here, we show that asymmetric SUMOylation of a conserved lysine residue in the N domain of both yeast (K178) and human (K191) Hsp90 facilitates both recruitment of the adenosine triphosphatase (ATPase)-activating cochaperone Aha1 and, unexpectedly, the binding of Hsp90 inhibitors, suggesting that these drugs associate preferentially with Hsp90 proteins that are actively engaged in the chaperone cycle. Importantly, cellular transformation is accompanied by elevated steady-state N domain SUMOylation, and increased Hsp90 SUMOylation sensitizes yeast and mammalian cells to Hsp90 inhibitors, providing a mechanism to explain the sensitivity of cancer cells to these drugs., (Copyright © 2014 Elsevier Inc. All rights reserved.)
- Published
- 2014
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41. Contributions of co-chaperones and post-translational modifications towards Hsp90 drug sensitivity.
- Author
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Walton-Diaz A, Khan S, Bourboulia D, Trepel JB, Neckers L, and Mollapour M
- Subjects
- Acetylation, Animals, Cell Cycle Proteins metabolism, Chaperonins metabolism, Cyclophilins metabolism, HSP90 Heat-Shock Proteins antagonists & inhibitors, HSP90 Heat-Shock Proteins chemistry, Homeodomain Proteins metabolism, Humans, Intramolecular Oxidoreductases metabolism, Phosphorylation, Prostaglandin-E Synthases, Protein Processing, Post-Translational, Tumor Suppressor Proteins metabolism, HSP90 Heat-Shock Proteins metabolism, Molecular Chaperones metabolism
- Abstract
Hsp90 is a molecular chaperone and important driver of stabilization and activation of several oncogenic proteins that are involved in the malignant transformation of tumor cells. Therefore, it is not surprising that Hsp90 has been reported to be a promising target for the treatment of several neoplasias, such as non-small-cell lung cancer and HER2-positive breast cancer. Hsp90 chaperone function depends on its ability to bind and hydrolyze ATP and Hsp90 inhibitors have been shown to compete with nucleotides for binding to Hsp90. Multiple factors, such as co-chaperones and post-translational modification, are involved in regulating Hsp90 ATPase activity. Here, the impact of post-translational modifications and co-chaperones on the efficacy of Hsp90 inhibitors are reviewed.
- Published
- 2013
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42. TIMP-2 modulates cancer cell transcriptional profile and enhances E-cadherin/beta-catenin complex expression in A549 lung cancer cells.
- Author
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Bourboulia D, Han H, Jensen-Taubman S, Gavil N, Isaac B, Wei B, Neckers L, and Stetler-Stevenson WG
- Subjects
- Animals, Cadherins metabolism, Cell Adhesion drug effects, Cell Adhesion genetics, Cell Line, Tumor, Drug Resistance, Neoplasm genetics, Epidermal Growth Factor pharmacology, Humans, Immunoblotting, Lung Neoplasms genetics, Lung Neoplasms metabolism, Lung Neoplasms pathology, Mice, Mice, Inbred NOD, Mice, SCID, Microscopy, Confocal, Mutation, Oligonucleotide Array Sequence Analysis, Protease Inhibitors metabolism, Protease Inhibitors pharmacology, Reverse Transcriptase Polymerase Chain Reaction, Tissue Inhibitor of Metalloproteinase-2 metabolism, Tissue Inhibitor of Metalloproteinase-2 pharmacology, Transplantation, Heterologous, beta Catenin metabolism, Cadherins genetics, Gene Expression Profiling, Gene Expression Regulation, Neoplastic, Tissue Inhibitor of Metalloproteinase-2 genetics, beta Catenin genetics
- Abstract
Tissue Inhibitor of Metalloproteinase 2 (TIMP-2) plays an essential role in regulating matrix remodeling, cell growth, differentiation, angiogenesis and apoptosis in vitro and in vivo. We have recently shown that TIMP-2-mediated inhibition of tumor growth is independent of matrix metalloproteinase-mediated mechanisms, and is a consequence of modulating both the tumor cells and the tumor microenvironment. In the current study we aim to identify the molecular pathways associated with these effects. We analyzed the transcriptional profile of the human lung cancer cell line A549 upon overexpression of TIMP-2 and Ala+TIMP-2 (mutant that does not inhibit MMP activity), and we found changes in gene expression predominantly related to decreased tumor development and metastasis. Increased E-cadherin expression in response to both TIMP-2 and Ala+TIMP-2 expression was confirmed by real time quantitative RT-PCR and immunoblotting. A549 cells treated with epidermal growth factor (EGF) displayed loss of cobblestone morphology and cell-cell contact, while cells overexpressing TIMP-2 or Ala+TIMP-2 were resistant to EGF-induced morphological changes. Moreover, exogenous treatment with recombinant Ala+TIMP-2 blocked EGF induced down-regulation of E-cadherin. In vivo, immunohistochemistry of A549 xenografts expressing either TIMP-2 or Ala+TIMP-2 demonstrated increased E-cadherin protein levels. More importantly, transcriptional profile analysis of tumor tissue revealed critical pathways associated with effects on tumor-host interaction and inhibition of tumor growth. In conclusion, we show that TIMP-2 promotes an anti-tumoral transcriptional profile in vitro and in vivo, including upregulation of E-cadherin, in A549 lung cancer cells.
- Published
- 2013
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43. Combined inhibition of Wee1 and Hsp90 activates intrinsic apoptosis in cancer cells.
- Author
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Iwai A, Bourboulia D, Mollapour M, Jensen-Taubman S, Lee S, Donnelly AC, Yoshida S, Miyajima N, Tsutsumi S, Smith AK, Sun D, Wu X, Blagg BS, Trepel JB, Stetler-Stevenson WG, and Neckers L
- Subjects
- Animals, Benzoquinones pharmacology, Cell Cycle Proteins metabolism, Cell Line, Tumor, Gene Deletion, HSP90 Heat-Shock Proteins metabolism, Humans, Lactams, Macrocyclic pharmacology, Male, Mice, Nuclear Proteins metabolism, Phosphorylation drug effects, Protein-Tyrosine Kinases metabolism, Saccharomyces cerevisiae Proteins antagonists & inhibitors, Saccharomyces cerevisiae Proteins metabolism, Survival Analysis, Xenograft Model Antitumor Assays, Apoptosis drug effects, Cell Cycle Proteins antagonists & inhibitors, HSP90 Heat-Shock Proteins antagonists & inhibitors, Nuclear Proteins antagonists & inhibitors, Prostatic Neoplasms enzymology, Prostatic Neoplasms pathology, Protein-Tyrosine Kinases antagonists & inhibitors
- Abstract
Heat shock protein 90 (Hsp90) is an essential, evolutionarily conserved molecular chaperone. Cancer cells rely on Hsp90 to chaperone mutated and/or activated oncoproteins, and its involvement in numerous signaling pathways makes it an attractive target for drug development. Surprisingly, however, the impact of Hsp90 inhibitors on cancer cells is frequently cytostatic in nature, and efforts to enhance the antitumor activity of Hsp90 inhibitors in the clinic remain a significant challenge. In agreement with previous data obtained using Wee1 siRNA, we show that dual pharmacologic inhibition of Wee1 tyrosine kinase and Hsp90 causes cancer cells to undergo apoptosis in vitro and in vivo. Gene expression profiling revealed that induction of the intrinsic apoptotic pathway by this drug combination coincided with transcriptional downregulation of Survivin and Wee1, an outcome not seen in cells treated separately with either agent. At the translational level, expression of these two proteins, as well as activated Akt, was completely abrogated. These data support the hypothesis that Wee1 inhibition sensitizes cancer cells to Hsp90 inhibitors; they establish combined Wee1/Hsp90 inhibition as a novel therapeutic strategy; and they provide a mechanistic rationale for enhancing the pro-apoptotic activity of Hsp90 inhibitors.
- Published
- 2012
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- View/download PDF
44. TIMP-2 targets tumor-associated myeloid suppressor cells with effects in cancer immune dysfunction and angiogenesis.
- Author
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Guedez L, Jensen-Taubman S, Bourboulia D, Kwityn CJ, Wei B, Caterina J, and Stetler-Stevenson WG
- Subjects
- Animals, Annexin A1 biosynthesis, CD40 Antigens biosynthesis, Carcinoma, Lewis Lung, Carcinoma, Non-Small-Cell Lung immunology, Carcinoma, Non-Small-Cell Lung pathology, Chemokine CCL5 biosynthesis, Female, Humans, Interferon-gamma biosynthesis, Interleukin-10 biosynthesis, Interleukin-11 biosynthesis, Interleukin-13 biosynthesis, Interleukin-6 blood, Lung Neoplasms immunology, Lung Neoplasms pathology, Metalloproteases biosynthesis, Mice, Mice, Inbred C57BL, Mice, Knockout, Mice, Nude, NF-kappa B biosynthesis, Tissue Inhibitor of Metalloproteinase-2 deficiency, Tissue Inhibitor of Metalloproteinase-2 genetics, Vascular Endothelial Growth Factor Receptor-1 metabolism, Carcinoma, Non-Small-Cell Lung metabolism, Lung Neoplasms metabolism, Myeloid Cells metabolism, Neovascularization, Pathologic, Tissue Inhibitor of Metalloproteinase-2 metabolism
- Abstract
Angiogenesis and inflammation are important therapeutic targets in non-small cell lung cancer (NSCLC). It is well known that proteolysis mediated by matrix metalloproteinases (MMPs) promotes angiogenesis and inflammation in the tumor microenvironment. Here, the effects of the MMP inhibitor TIMP-2 on NSCLC inflammation and angiogenesis were evaluated in TIMP-2-deficient (timp2-/-) mice injected subcutaneously (SC) with Lewis lung carcinoma cells and compared with the effects on tumors in wild-type mice. TIMP-2-deficient mice demonstrated increased tumor growth, enhanced expression of angiogenic marker αvβ3 in tumor and endothelial cells, and significantly higher serum vascular endothelial growth factor-A levels. Tumor-bearing timp2-/- mice showed a significant number of inflammatory cells in their tumors, upregulation of inflammation mediators, nuclear factor-kappaB, and Annexin A1, as well as higher levels of serum interleukin (IL)-6. Phenotypic analysis revealed an increase in myeloid-derived suppressor cell (MDSC) cells (CD11b+ and Gr-1+) that coexpressed vascular-endothelial-growth factor receptor 1 (VEGF-R1) and elevated MMP activation present in tumors and spleens from timp2-/- mice. Furthermore, TIMP-2-deficient tumors upregulated expression of the immunosuppressing genes controlling MDSC growth, IL-10, IL-13, IL-11, and chemokine ligand (CCL-5/RANTES), and decreased interferon-γ and increased CD40L. Moreover, forced TIMP-2 expression in human lung adenocarcinoma A-549 resulted in a significant reduction of MDSCs recruited into tumors, as well as suppression of angiogenesis and tumor growth. The increase in MDSCs has been linked to cancer immunosuppression and angiogenesis. Therefore, this study supports TIMP-2 as a negative regulator of MDSCs with important implications for the immunotherapy and/or antiangiogenic treatment of NSCLC.
- Published
- 2012
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- View/download PDF
45. TIMP-2: An Endogenous Angiogenesis Inhibitor with Distinct Antitumoral Properties.
- Author
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Bourboulia D, Jensen-Taubman S, and Stetler-Stevenson WG
- Abstract
Competing Interests: Conflict of Interest The authors have no conflicts, financial or otherwise to declare.
- Published
- 2012
46. Endogenous angiogenesis inhibitor blocks tumor growth via direct and indirect effects on tumor microenvironment.
- Author
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Bourboulia D, Jensen-Taubman S, Rittler MR, Han HY, Chatterjee T, Wei B, and Stetler-Stevenson WG
- Subjects
- Adenocarcinoma enzymology, Animals, Apoptosis physiology, Cell Movement, Cell Proliferation, Female, Focal Adhesion Protein-Tyrosine Kinases metabolism, Humans, Lung Neoplasms enzymology, Mice, Mice, Nude, Microvessels, Neoplasm Invasiveness, Neoplasm Transplantation, Proto-Oncogene Proteins c-akt metabolism, Tissue Inhibitor of Metalloproteinase-2 metabolism, Transplantation, Heterologous, Tumor Cells, Cultured, Adenocarcinoma blood supply, Lung Neoplasms blood supply, Matrix Metalloproteinase Inhibitors, Neovascularization, Pathologic enzymology, Tissue Inhibitor of Metalloproteinase-2 physiology, Tumor Microenvironment physiology
- Abstract
Tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) belongs to a small family of endogenous proteins that inhibits a group of enzymes, the matrix metalloproteinases (MMPs). TIMP-2 inhibits endothelial cell proliferation and migration in vitro and angiogenesis in vivo, through MMP-dependent and -independent mechanisms. However, little is known regarding the contribution of these mechanisms to the antitumor effects of TIMP-2. Using a retroviral delivery system, we stably overexpressed TIMP-2 and its mutant Ala+TIMP-2 (devoid of MMP inhibitory activity) in human adenocarcinoma A549 cells. Using real time PCR, and enzyme-linked immunosorbent assay (ELISA), we confirmed enhanced TIMP-2 expression and its MMP inhibitory activity by reverse zymography. In vitro, growth assays suggested that TIMP-2 and Ala+TIMP-2 did not alter basal cell proliferation rates, however, tumor cell migration and invasion were inhibited. In vivo, both TIMP-2 and Ala+TIMP-2 A549 xenografts exhibited reduced growth rate, CD31 immunostaining indicated decreased intratumoral microvascular density, and TUNEL demonstrated enhanced tumor cell apoptosis. Immunoblotting and immunohistochemical analyses of A549 xenograft tissues with either phospho-FAK (Tyr397) or phospho-AKT (Ser473) showed decreased activation in both TIMP-2 and Ala+TIMP-2 tumor cells. We conclude that TIMP-2-mediated inhibition of tumor growth occurs, at least in part, independently of MMP inhibition, and is a consequence of both direct effects of TIMP-2 on tumor cells and modulation of the tumor microenvironment., (Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2011
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47. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs): Positive and negative regulators in tumor cell adhesion.
- Author
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Bourboulia D and Stetler-Stevenson WG
- Subjects
- Cell Adhesion, Cell Adhesion Molecules metabolism, Disease Progression, Down-Regulation physiology, Extracellular Matrix metabolism, Extracellular Matrix physiology, Humans, Matrix Metalloproteinases metabolism, Models, Biological, Neoplasms metabolism, Tissue Inhibitor of Metalloproteinases metabolism, Up-Regulation physiology, Matrix Metalloproteinases physiology, Neoplasms enzymology, Neoplasms pathology, Tissue Inhibitor of Metalloproteinases physiology
- Abstract
Cells adhere to one another and/or to matrices that surround them. Regulation of cell-cell (intercellular) and cell-matrix adhesion is tightly controlled in normal cells, however, defects in cell adhesion are common in the majority of human cancers. Multilateral communication among tumor cells with the extracellular matrix (ECM) and neighbor cells is accomplished through adhesion molecules, ECM components, proteolytic enzymes and their endogenous inhibitors. There is sufficient evidence to suggest that reduced adherence is a tumor cell property engaged during tumor progression. Tumor cells acquire the ability to change shape, detach and easily move through spaces disorganizing the normal tissue architecture. This property is due to changes in expression levels of adhesion molecules and/or due to elevated levels of secreted proteolytic enzymes, including matrix metalloproteinases (MMPs). Among other roles, MMPs degrade the ECM and, therefore, prepare the path for tumor cells to migrate, invade and spread to distant secondary areas, where they form metastasis. Tissue inhibitors of metalloproteinases or TIMPs control MMP activities and, therefore, minimize matrix degradation. Both MMPs and TIMPs are involved in tissue remodeling and decisively regulate tumor cell progression including tumor angiogenesis. In this review, we describe and discuss data that support the important role of MMPs and TIMPs in cancer cell adhesion and tumor progression., (Published by Elsevier Ltd.)
- Published
- 2010
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48. Swe1Wee1-dependent tyrosine phosphorylation of Hsp90 regulates distinct facets of chaperone function.
- Author
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Mollapour M, Tsutsumi S, Donnelly AC, Beebe K, Tokita MJ, Lee MJ, Lee S, Morra G, Bourboulia D, Scroggins BT, Colombo G, Blagg BS, Panaretou B, Stetler-Stevenson WG, Trepel JB, Piper PW, Prodromou C, Pearl LH, and Neckers L
- Subjects
- Cell Cycle Proteins antagonists & inhibitors, Cell Cycle Proteins genetics, Cell Line, Tumor, Dimerization, HSP90 Heat-Shock Proteins physiology, Humans, Nuclear Proteins antagonists & inhibitors, Nuclear Proteins genetics, Nuclear Proteins physiology, Phosphorylation, Proteasome Endopeptidase Complex metabolism, Protein-Tyrosine Kinases antagonists & inhibitors, Protein-Tyrosine Kinases genetics, RNA Interference, Saccharomyces cerevisiae Proteins antagonists & inhibitors, Saccharomyces cerevisiae Proteins genetics, Ubiquitination, Cell Cycle Proteins physiology, HSP90 Heat-Shock Proteins metabolism, Protein-Tyrosine Kinases physiology, Saccharomyces cerevisiae Proteins physiology, Tyrosine metabolism
- Abstract
Saccharomyces WEE1 (Swe1), the only "true" tyrosine kinase in budding yeast, is an Hsp90 client protein. Here we show that Swe1(Wee1) phosphorylates a conserved tyrosine residue (Y24 in yeast Hsp90 and Y38 in human Hsp90alpha) in the N domain of Hsp90. Phosphorylation is cell-cycle associated and modulates the ability of Hsp90 to chaperone a selected clientele, including v-Src and several other kinases. Nonphosphorylatable mutants have normal ATPase activity, support yeast viability, and productively chaperone the Hsp90 client glucocorticoid receptor. Deletion of SWE1 in yeast increases Hsp90 binding to its inhibitor geldanamycin, and pharmacologic inhibition/silencing of Wee1 sensitizes cancer cells to Hsp90 inhibitor-induced apoptosis. These findings demonstrate that Hsp90 chaperoning of distinct client proteins is differentially regulated by specific posttranslational modification of a unique subcellular pool of the chaperone, and they provide a strategy to increase the cellular potency of Hsp90 inhibitors.
- Published
- 2010
- Full Text
- View/download PDF
49. Kaposi's sarcoma-associated herpesvirus-encoded interleukin-6 and G-protein-coupled receptor regulate angiopoietin-2 expression in lymphatic endothelial cells.
- Author
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Vart RJ, Nikitenko LL, Lagos D, Trotter MW, Cannon M, Bourboulia D, Gratrix F, Takeuchi Y, and Boshoff C
- Subjects
- Angiopoietin-2 genetics, Endothelial Cells metabolism, Endothelial Cells virology, Gene Expression Regulation, Neoplastic, Gene Library, Humans, Interleukin-6 metabolism, MAP Kinase Signaling System, Mitogen-Activated Protein Kinases metabolism, Neovascularization, Pathologic genetics, Neovascularization, Pathologic metabolism, Neovascularization, Pathologic virology, Receptors, G-Protein-Coupled metabolism, Sarcoma, Kaposi blood supply, Sarcoma, Kaposi genetics, Sarcoma, Kaposi metabolism, Up-Regulation, Angiopoietin-2 biosynthesis, Herpesvirus 8, Human genetics, Interleukin-6 genetics, Receptors, G-Protein-Coupled genetics, Sarcoma, Kaposi virology
- Abstract
Kaposi's sarcoma (KS) is caused by Kaposi's sarcoma-associated herpesvirus (KSHV) and consists of proliferating spindle cells, which are related to lymphatic endothelial cells (LEC). Angiopoietin-2 (Ang2) is a secreted proangiogenic and lymphangiogenic molecule. Here, we show the expression of Ang2 protein in KS and confirm that KSHV infection up-regulates Ang2 in LEC. We show that a paracrine mechanism contributes to this up-regulation. A lentiviral library of individual KSHV-encoding genes, comprising the majority of known latent genes and a selection of lytic viral genes, was constructed to investigate the underlying mechanism of this up-regulation. Two lytic genes, viral interleukin-6 (vIL6) and viral G-protein-coupled receptor (vGPCR), up-regulated Ang2 expression in LEC. Both vIL6 and vGPCR are expressed in KSHV-infected LEC and caused up-regulation of Ang2 in a paracrine manner. KSHV, vIL6, and vGPCR up-regulated Ang2 through the mitogen-activated protein kinase (MAPK) pathway. Gene expression microarray analysis identified several other angiogenic molecules affected by KSHV, including the vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR) axis, which is also affected by vIL6 and vGPCR in LEC, and matrix metalloproteinases, which could act in concert with Ang2 to contribute to KS development. These findings support the paracrine and autocrine roles of the lytic KSHV-encoded proteins, vIL6 and vGPCR, in KS pathogenesis and identify Ang2 as a potential therapeutic target for this neoplasm.
- Published
- 2007
- Full Text
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50. Transformation of human mesenchymal stem cells increases their dependency on oxidative phosphorylation for energy production.
- Author
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Funes JM, Quintero M, Henderson S, Martinez D, Qureshi U, Westwood C, Clements MO, Bourboulia D, Pedley RB, Moncada S, and Boshoff C
- Subjects
- Adult, Blotting, Western, Cell Transformation, Neoplastic genetics, Gene Expression Regulation, Neoplastic physiology, Glucose metabolism, Glucosephosphate Dehydrogenase metabolism, Glycolysis physiology, Humans, Immunophenotyping, Lactic Acid metabolism, Male, Mesenchymal Stem Cells metabolism, NADP metabolism, Adenosine Triphosphate biosynthesis, Cell Transformation, Neoplastic metabolism, Energy Metabolism physiology, Mesenchymal Stem Cells physiology, Oxidative Phosphorylation
- Abstract
An increased dependency on glycolysis for ATP production is considered to be a hallmark of tumor cells. Whether this increase in glycolytic activity is due mainly to inherent metabolic alterations or to the hypoxic microenvironment remains controversial. Here we have transformed human adult mesenchymal stem cells (MSC) using genetic alterations as described for differentiated cells. Our data suggest that MSC require disruption of the same pathways as have been shown for differentiated cells to confer a fully transformed phenotype. Furthermore, we found that MSC are more glycolytic than primary human fibroblasts and, in contrast to differentiated cells, do not depend on increased aerobic glycolysis for ATP production during transformation. These data indicate that aerobic glycolysis (the Warburg effect) is not an intrinsic component of the transformation of adult stem cells, and that oncogenic adaptation to bioenergetic requirements, in some circumstances, may also rely on increases in oxidative phosphorylation. We did find, however, a reversible increase in the transcription of glycolytic enzymes in tumors generated by transformed MSC, indicating this is a secondary phenomenon resulting from adaptation of the tumor to its microenvironment.
- Published
- 2007
- Full Text
- View/download PDF
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