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Stigler RG, Becker K, Hasanov E, Hörmann R, Gassner R, Lepperdinger G. Osteocyte numbers decrease only in postcranial but not in cranial bones in humans of advanced age. Ann Anat 2019; 226:57-63. [PMID: 31330307 DOI: 10.1016/j.aanat.2019.06.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 06/24/2019] [Accepted: 06/25/2019] [Indexed: 12/29/2022]
Abstract
BACKGROUND Bone ageing is governed by the linked activities of short-lived osteoblasts and osteoclasts in conjunction with long-lived osteocytes present in osseous structure. Besides their maintenance function, osteogenic cells also gain specific positional information, which may potentially trigger ageing-associated cellular deviations in terminally differentiated osteocytes differently in cranial versus postcranial tissues. METHODS We therefore investigated bone taken from deceased aged humans explanted at five distinct anatomical positions throughout the body and assessed physical and biological determinants applying radiologic and histologic measures. RESULTS We were able to show that significantly more osteocytes reside in aged cortical bone at cranial positions than within axial or limb skeleton. These cellular states and conditions were not found in the corresponding trabecular bone, where osteocyte numbers remain also high at postcranial positions. Parallel comparative analyses of bone microstructure as analyzed by means of computer tomography showed no significant differences. CONCLUSIONS Considering differences and commonalities regarding the bone samples, such as loading, mechanisms of ossification or the surrounding stromal cell compartment, our findings indicate that positional information laid down during ontogenetic processes is instructive during the entire life thus potentially also moulding spatial-specific mechanistic distinctions of bone ageing.
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Affiliation(s)
- Robert G Stigler
- Department of Oral and Maxillofacial Surgery, Medical University Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria
| | - Kathrin Becker
- Department of Orthodontics, Universitätsklinikum Düsseldorf, Morrenstr. 5, 40225 Düsseldorf, Germany.
| | - Elvin Hasanov
- Department of Oral and Maxillofacial Surgery, Medical University Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria
| | - Romed Hörmann
- Division of Clinical and Functional Anatomy, Medical University Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria
| | - Robert Gassner
- Department of Oral and Maxillofacial Surgery, Medical University Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria
| | - Günter Lepperdinger
- Department of Biosciences, University Salzburg, Hellbrunnerstr 34, 5020 Salzburg, Austria
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Jonasch E, Hasanov E, Corn PG, Moss T, Shaw KR, Stovall S, Marcott V, Gan B, Bird S, Wang X, Do KA, Altamirano PF, Zurita AJ, Doyle LA, Lara PN, Tannir NM. A randomized phase 2 study of MK-2206 versus everolimus in refractory renal cell carcinoma. Ann Oncol 2017; 28:804-808. [PMID: 28049139 DOI: 10.1093/annonc/mdw676] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Indexed: 01/28/2023] Open
Abstract
Background Activation of the phosphoinisitide-3 kinase (PI3K) pathway through mutation and constitutive upregulation has been described in renal cell carcinoma (RCC), making it an attractive target for therapeutic intervention. We performed a randomized phase II study in vascular endothelial growth factor (VEGF) therapy refractory patients to determine whether MK-2206, an allosteric inhibitor of AKT, was more efficacious than the mammalian target of rapamycin inhibitor everolimus. Patients and methods A total of 43 patients were randomized in a 2:1 distribution, with 29 patients assigned to the MK-2206 arm and 14 to the everolimus arm. Progression-free survival (PFS) was the primary endpoint. Results The trial was closed at the first futility analysis with an observed PFS of 3.68 months in the MK-2206 arm and 5.98 months in the everolimus arm. Dichotomous response rate profiles were seen in the MK-2206 arm with one complete response and three partial responses in the MK-2206 arm versus none in the everolimus arm. On the other hand, progressive disease was best response in 44.8% of MK2206 versus 14.3% of everolimus-treated patients. MK-2206 induced significantly more rash and pruritis than everolimus, and dose reduction occurred in 37.9% of MK-2206 versus 21.4% of everolimus-treated patients. Genomic analysis revealed that 57.1% of the patients in the PD group had either deleterious TP53 mutations or ATM mutations or deletions. In contrast, none of the patients in the non-PD group had TP53 or ATM defects. No predictive marker for response was observed in this small dataset. Conclusions Dichotomous outcomes are observed when VEGF therapy refractory patients are treated with MK-2206, and MK-2206 does not demonstrate superiority to everolimus. Additionally, mutations in DNA repair genes are associated with early disease progression, indicating that dysregulation of DNA repair is associated with a more aggressive tumor phenotype in RCC.
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Affiliation(s)
- E Jonasch
- Division of Cancer Medicine, Department of Genitourinary Medical Oncology, The University of Texas MD Anderson, Houston, TX, USA
| | - E Hasanov
- Division of Cancer Medicine, Department of Genitourinary Medical Oncology, The University of Texas MD Anderson, Houston, TX, USA
| | - P G Corn
- Division of Cancer Medicine, Department of Genitourinary Medical Oncology, The University of Texas MD Anderson, Houston, TX, USA
| | - T Moss
- Division of Cancer Medicine, Department of Genitourinary Medical Oncology, The University of Texas MD Anderson, Houston, TX, USA
| | - K R Shaw
- Division of Cancer Medicine, Department of Genitourinary Medical Oncology, The University of Texas MD Anderson, Houston, TX, USA
| | - S Stovall
- Division of Cancer Medicine, Department of Genitourinary Medical Oncology, The University of Texas MD Anderson, Houston, TX, USA
| | - V Marcott
- Division of Cancer Medicine, Department of Genitourinary Medical Oncology, The University of Texas MD Anderson, Houston, TX, USA
| | - B Gan
- Division of Cancer Medicine, Department of Genitourinary Medical Oncology, The University of Texas MD Anderson, Houston, TX, USA
| | - S Bird
- Division of Cancer Medicine, Department of Genitourinary Medical Oncology, The University of Texas MD Anderson, Houston, TX, USA
| | - X Wang
- Division of Cancer Medicine, Department of Genitourinary Medical Oncology, The University of Texas MD Anderson, Houston, TX, USA
| | - K A Do
- Division of Cancer Medicine, Department of Genitourinary Medical Oncology, The University of Texas MD Anderson, Houston, TX, USA
| | - P F Altamirano
- Division of Cancer Medicine, Department of Genitourinary Medical Oncology, The University of Texas MD Anderson, Houston, TX, USA
| | - A J Zurita
- Division of Cancer Medicine, Department of Genitourinary Medical Oncology, The University of Texas MD Anderson, Houston, TX, USA
| | - L A Doyle
- Investigational Drug Branch, Cancer Therapy Evaluation Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute, Bethesda, Maryland, USA
| | - P N Lara
- UC Davis Comprehensive Cancer Center, Sacramento, CA, USA
| | - N M Tannir
- Division of Cancer Medicine, Department of Genitourinary Medical Oncology, The University of Texas MD Anderson, Houston, TX, USA
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Hasanov E, Chen G, Chowdhury P, Weldon J, Ding Z, Jonasch E, Sen S, Walker CL, Dere R. Ubiquitination and regulation of AURKA identifies a hypoxia-independent E3 ligase activity of VHL. Oncogene 2017; 36:3450-3463. [PMID: 28114281 PMCID: PMC5485216 DOI: 10.1038/onc.2016.495] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 11/15/2016] [Accepted: 11/29/2016] [Indexed: 12/18/2022]
Abstract
The hypoxia-regulated tumor-suppressor von Hippel-Lindau (VHL) is an E3 ligase that recognizes its substrates as part of an oxygen-dependent prolyl hydroxylase (PHD) reaction, with hypoxia-inducible factor α (HIFα) being its most notable substrate. Here we report that VHL has an equally important function distinct from its hypoxia-regulated activity. We find that Aurora kinase A (AURKA) is a novel, hypoxia-independent target for VHL ubiquitination. In contrast to its hypoxia-regulated activity, VHL mono-, rather than poly-ubiquitinates AURKA, in a PHD-independent reaction targeting AURKA for degradation in quiescent cells, where degradation of AURKA is required to maintain the primary cilium. Tumor-associated variants of VHL differentiate between these two functions, as a pathogenic VHL mutant that retains intrinsic ability to ubiquitinate HIFα is unable to ubiquitinate AURKA. Together, these data identify VHL as an E3 ligase with important cellular functions under both normoxic and hypoxic conditions.
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Affiliation(s)
- E Hasanov
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA.,Department of Basic Oncology, Hacettepe University Cancer Institute, Sihhiye, Ankara, Turkey
| | - G Chen
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA
| | - P Chowdhury
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA.,Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, USA
| | - J Weldon
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA
| | - Z Ding
- Department of Systems Biology, U.T. M.D. Anderson Cancer Center, Houston, TX, USA
| | - E Jonasch
- Department of Genitourinary Medical Oncology, U.T. M.D. Anderson Cancer Center, Houston, TX, USA
| | - S Sen
- Department of Translational Molecular Pathology, U.T. M.D. Anderson Cancer Center, Houston, TX, USA
| | - C L Walker
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA.,Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, USA
| | - R Dere
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA.,Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, USA
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