1
|
Wang Y, Liu X, Huang W, Liang J, Chen Y. The intricate interplay between HIFs, ROS, and the ubiquitin system in the tumor hypoxic microenvironment. Pharmacol Ther 2022; 240:108303. [PMID: 36328089 DOI: 10.1016/j.pharmthera.2022.108303] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 10/16/2022] [Accepted: 10/26/2022] [Indexed: 11/09/2022]
Abstract
Alterations in protein ubiquitination and hypoxia-inducible factor (HIF) signaling both contribute to tumorigenesis and tumor progression. Ubiquitination is a dynamic process that is coordinately regulated by E3 ligases and deubiquitinases (DUBs), which have emerged as attractive therapeutic targets. HIF expression and transcriptional activity are usually increased in tumors, leading to poor clinical outcomes. Reactive oxygen species (ROS) are upregulated in tumors and have multiple effects on HIF signaling and the ubiquitin system. A growing body of evidence has shown that multiple E3 ligases and UBDs function synergistically to control the expression and activity of HIF, thereby allowing cancer cells to cope with the hypoxic microenvironment. Conversely, several E3 ligases and DUBs are regulated by hypoxia and/or HIF signaling. Hypoxia also induces ROS production, which in turn modulates the stability or activity of HIF, E3 ligases, and DUBs. Understanding the complex networks between E3 ligase, DUBs, ROS, and HIF will provide insights into the fundamental mechanism of the cellular response to hypoxia and help identify novel molecular targets for cancer treatment. We review the current knowledge on the comprehensive relationship between E3 ligase, DUBs, ROS, and HIF signaling, with a particular focus on the use of E3 ligase or DUB inhibitors in cancer.
Collapse
Affiliation(s)
- Yijie Wang
- Institute of Biomedical Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Center for Cell Structure and Function, College of Life Sciences, Shandong Normal University, Jinan, Shandong 250014, China
| | - Xiong Liu
- School of Medicine, Jinan University, Guangzhou, Guangdong 510632, China
| | - Weixiao Huang
- School of Medicine, Jinan University, Guangzhou, Guangdong 510632, China
| | - Junjie Liang
- The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, China.
| | - Yan Chen
- Institute of Biomedical Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Center for Cell Structure and Function, College of Life Sciences, Shandong Normal University, Jinan, Shandong 250014, China; School of Medicine, Jinan University, Guangzhou, Guangdong 510632, China.
| |
Collapse
|
2
|
Liu Z, Li L, Yi Z, Duan H, Lu R, Li C, Li L, Gong K. Biological and clinical impact of central nervous system hemangioblastomas in Chinese patients with von Hippel-Lindau disease: implications for treatment. Hered Cancer Clin Pract 2020; 18:21. [PMID: 33110457 PMCID: PMC7583299 DOI: 10.1186/s13053-020-00153-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 10/19/2020] [Indexed: 12/15/2022] Open
Abstract
Objective Central nervous system (CNS) hemangioblastomas (HGBs) are the most frequent cause of mortality in patients with von Hippel-Lindau (VHL) genetic syndrome. However, there is a lack of large studies on the clinical features and optimal management of HGBs in Chinese patients. Methods VHL-related HGB cases treated surgically at our hospital from 2012 to 2019 were evaluated. Patients and family members meeting the clinical diagnostic criteria underwent genetic testing. Clinical, genetic and relevant imaging data were analyzed. Results Eighty-five VHL patients from 34 pedigrees in 16 Chinese provinces who underwent 121 operations for CNS HGBs were enrolled. Multiple operations were associated with a younger age at first operation (OR = 0.926, 95% CI = 0.871–0.985, P = 0.014, threshold: 27.5, sensitivity: 72.2%, specificity: 71.2%) and a longer postoperative period (OR = 1.096, 95% CI = 1.015–1.184, P = 0.019, threshold: 10.5, sensitivity: 66.7%, specificity: 76.3%). The age at first operation was younger in children than in their parents (23 pairs, P < 0.001). The age at first operation was younger in siblings born later than in those born earlier (10 pairs, P = 0.01). Most untreated tumors (98.2%) remained relatively stable during follow-up (range, 0.5–7; median, 2). However, new tumors continued to emerge (0.14 tumor/year). Conclusion VHL-associated CNS HGB is a long-term chronic disease with repeated attacks, likely with genetic anticipation in Chinese pedigrees. When the age at first operation is under 27.5 years, or the postoperative period is longer than 10.5 years, the risk of multiple operations is increased. While most unresected HGBs remain stable after surgery, new tumors may still slowly emerge; hence, scheduled follow-ups are necessary.
Collapse
Affiliation(s)
- Zhen Liu
- Department of Neurosurgery, Peking University First Hospital, No. 8 Xishiku Street, Xicheng District, Beijing, 100034 China
| | - Liang Li
- Department of Neurosurgery, Peking University First Hospital, No. 8 Xishiku Street, Xicheng District, Beijing, 100034 China
| | - Zhiqiang Yi
- Department of Neurosurgery, Peking University First Hospital, No. 8 Xishiku Street, Xicheng District, Beijing, 100034 China
| | - Hongzhou Duan
- Department of Neurosurgery, Peking University First Hospital, No. 8 Xishiku Street, Xicheng District, Beijing, 100034 China
| | - Runchun Lu
- Department of Neurosurgery, Peking University First Hospital, No. 8 Xishiku Street, Xicheng District, Beijing, 100034 China
| | - Chunwei Li
- Department of Neurosurgery, Peking University First Hospital, No. 8 Xishiku Street, Xicheng District, Beijing, 100034 China
| | - Lei Li
- Department of Urology, Peking University First Hospital, Beijing, 100034 China
| | - Kan Gong
- Department of Urology, Peking University First Hospital, Beijing, 100034 China
| |
Collapse
|
3
|
Liu Z, Zhou J, Li L, Yi Z, Lu R, Li C, Gong K. Intronic mutation of the VHL gene associated with central nervous system hemangioblastomas in two Chinese families with Von Hippel-Lindau disease: case report. BMC MEDICAL GENETICS 2020; 21:191. [PMID: 33004005 PMCID: PMC7528461 DOI: 10.1186/s12881-020-01126-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 09/21/2020] [Indexed: 11/10/2022]
Abstract
Background Central nervous system (CNS) hemangioblastomas are the most frequent cause of mortality in patients with Von Hippel–Lindau (VHL) disease, an autosomal dominant genetic disease resulting from germline mutations in the VHL tumor suppressor gene, with most mutations occurring in the exons. To date, there have been no reports of CNS hemangioblastoma cases related to pathogenic variants in intron 2 of VHL, which encodes a tumor suppressor protein (i.e., pVHL) that regulates hypoxia-inducible factor proteins. Case presentation We report the presence of a base substitution of c.464-1G > C and c.464-2A > G in the intron 2 of VHL causing CNS hemangioblastomas in six patients with VHL from two Chinese families. The clinical information about the two pathogentic variants has been submitted to ClinVar database. The ClinVar accession for NM_000551.3(VHL):c.464-1G > C was SCV001371687. This finding may provide a new approach for diagnosing and researching VHL-associated hemangioblastomas. Conclusions This is the first report of a pathogenic variant at intron 2 in VHL-associated hemangioblastomas. Gene sequencing showed that not only exonic but also intronic mutations can lead to the development of CNS hemangioblastomas.
Collapse
Affiliation(s)
- Zhen Liu
- Department of Neurosurgery, Peking University First Hospital, No. 8 Xishiku Street, Xicheng District, Beijing, 100034, China
| | - Jingcheng Zhou
- Department of Urology, Peking University First Hospital, Beijing, 100034, China
| | - Liang Li
- Department of Neurosurgery, Peking University First Hospital, No. 8 Xishiku Street, Xicheng District, Beijing, 100034, China.
| | - Zhiqiang Yi
- Department of Neurosurgery, Peking University First Hospital, No. 8 Xishiku Street, Xicheng District, Beijing, 100034, China
| | - Runchun Lu
- Department of Neurosurgery, Peking University First Hospital, No. 8 Xishiku Street, Xicheng District, Beijing, 100034, China
| | - Chunwei Li
- Department of Neurosurgery, Peking University First Hospital, No. 8 Xishiku Street, Xicheng District, Beijing, 100034, China
| | - Kan Gong
- Department of Urology, Peking University First Hospital, Beijing, 100034, China
| |
Collapse
|
4
|
Liu Z, Li L, Yi Z, Duan H, Lu R, Li C, Zhou J, Gong K. Overexpression of EGFR and TGFα in von Hippel-Lindau-Related Central Nervous System Hemangioblastomas. Front Oncol 2020; 10:703. [PMID: 32432044 PMCID: PMC7214834 DOI: 10.3389/fonc.2020.00703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 04/15/2020] [Indexed: 01/27/2023] Open
Abstract
Background: Central nervous system (CNS) hemangioblastomas (HGBs) are the most frequent cause of mortality in patients with von Hippel–Lindau (VHL) disease. Characteristics of multiple and recurrent disease cause certain difficulties in the treatment of CNS HGBs. Methods: VHL-related HGB cases treated surgically at our hospital from September 2015 to February 2019 were analyzed. Patients meeting the clinical diagnostic criteria underwent genetic testing. Real-time PCR and immunohistochemistry were used in HGBs to verify differential expression of mRNAs and proteins, respectively. Furthermore, correlations between the differentially expressed proteins and the histological grading, genetic mutations, and tumor burden were also analyzed. Results: A total of 21 patients with VHL syndrome confirmed by genetic testing (missense group, 9; partial deletion group, 12) were enrolled, and 30 CNS HGBs from these patients were studied. Clinical data showed that men at first operation were significantly younger than females (p = 0.005). Real-time PCR demonstrated that EGFR (p = 0.017) and TGFα (p = 0.017) mRNA expression in VHL-related HGBs was significantly higher than that in the control group. Immunohistochemistry showed that the mean optical density in VHL-related HGBs was significantly higher than that in controls (EGFR, p = 0.007; TGFα, p = 0.021). Finally, the cyst volume was related to the upregulation of EGFR (r = 0.782, p < 0.01). Conclusion: Overexpression of EGFR and TGFα may contribute to tumor growth in VHL-related CNS HGBs. The cyst volume was associated with EGFR overexpression. These results provide information for the management of VHL-related HGBs in the era of targeted therapeutics.
Collapse
Affiliation(s)
- Zhen Liu
- Department of Neurosurgery, Peking University First Hospital, Beijing, China
| | - Liang Li
- Department of Neurosurgery, Peking University First Hospital, Beijing, China
| | - Zhiqiang Yi
- Department of Neurosurgery, Peking University First Hospital, Beijing, China
| | - Hongzhou Duan
- Department of Neurosurgery, Peking University First Hospital, Beijing, China
| | - Runchun Lu
- Department of Neurosurgery, Peking University First Hospital, Beijing, China
| | - Chunwei Li
- Department of Neurosurgery, Peking University First Hospital, Beijing, China
| | - Jingcheng Zhou
- Department of Urology, Peking University First Hospital, Beijing, China
| | - Kan Gong
- Department of Urology, Peking University First Hospital, Beijing, China
| |
Collapse
|
5
|
Mennerich D, Kubaichuk K, Kietzmann T. DUBs, Hypoxia, and Cancer. Trends Cancer 2019; 5:632-653. [PMID: 31706510 DOI: 10.1016/j.trecan.2019.08.005] [Citation(s) in RCA: 126] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 08/24/2019] [Accepted: 08/27/2019] [Indexed: 02/08/2023]
Abstract
Alterations in protein ubiquitylation and hypoxia are commonly associated with cancer. Ubiquitylation is carried out by three sequentially acting ubiquitylating enzymes and can be opposed by deubiquitinases (DUBs), which have emerged as promising drug targets. Apart from protein localization and activity, ubiquitylation regulates degradation of proteins, among them hypoxia-inducible factors (HIFs). Thereby, various E3 ubiquitin ligases and DUBs regulate HIF abundance. Conversely, several E3s and DUBs are regulated by hypoxia. While hypoxia is a powerful HIF regulator, less is known about hypoxia-regulated DUBs and their impact on HIFs. Here, we review current knowledge about the relationship of E3s, DUBs, and hypoxia signaling. We also discuss the reciprocal regulation of DUBs by hypoxia and use of DUB-specific drugs in cancer.
Collapse
Affiliation(s)
- Daniela Mennerich
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, 90570, Finland
| | - Kateryna Kubaichuk
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, 90570, Finland
| | - Thomas Kietzmann
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, 90570, Finland; Biocenter Oulu, University of Oulu, Oulu, 90570, Finland.
| |
Collapse
|
6
|
Involvement of E3 Ligases and Deubiquitinases in the Control of HIF-α Subunit Abundance. Cells 2019; 8:cells8060598. [PMID: 31208103 PMCID: PMC6627837 DOI: 10.3390/cells8060598] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 06/07/2019] [Accepted: 06/13/2019] [Indexed: 12/21/2022] Open
Abstract
The ubiquitin and hypoxia-inducible factor (HIF) pathways are cellular processes involved in the regulation of a variety of cellular functions. Enzymes called ubiquitin E3 ligases perform protein ubiquitylation. The action of these enzymes can be counteracted by another group of enzymes called deubiquitinases (DUBs), which remove ubiquitin from target proteins. The balanced action of these enzymes allows cells to adapt their protein content to a variety of cellular and environmental stress factors, including hypoxia. While hypoxia appears to be a powerful regulator of the ubiquitylation process, much less is known about the impact of DUBs on the HIF system and hypoxia-regulated DUBs. Moreover, hypoxia and DUBs play crucial roles in many diseases, such as cancer. Hence, DUBs are considered to be promising targets for cancer cell-specific treatment. Here, we review the current knowledge about the role DUBs play in the control of HIFs, the regulation of DUBs by hypoxia, and their implication in cancer progression.
Collapse
|
7
|
Disseminated central nervous system hemangioblastoma in a patient with no clinical or genetic evidence of von Hippel-Lindau disease-a case report and literature review. Acta Neurochir (Wien) 2019; 161:343-349. [PMID: 30652202 DOI: 10.1007/s00701-019-03800-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/04/2019] [Indexed: 10/27/2022]
Abstract
BACKGROUND Hemangioblastomas (HB) are benign tumors of the central nervous system (CNS) that can appear sporadic or as part of von Hippel-Lindau (VHL) disease. It is often curable with surgical resection, but upon relapse, the disease exhibits a treatment-refractory course. CASE REPORT A patient treated for sporadic cerebellar HB relapsed 12 years post-surgery. She developed disseminated disease throughout the CNS, including leptomeningeal manifestations. Repeat surgery and craniospinal radiation therapy were unsuccessful. CONCLUSION This case is in line with previous publications on disseminated non-VHL HB. Available treatment options are inefficient, emphasizing the need for improved understanding of HB biology to identify therapeutic targets.
Collapse
|
8
|
Muscarella LA, Bisceglia M, Galliani CA, Zidar N, Ben-Dor DJ, Pasquinelli G, la Torre A, Sparaneo A, Fanburg-Smith JC, Lamovec J, Michal M, Bacchi CE. Extraneuraxial hemangioblastoma: A clinicopathologic study of 10 cases with molecular analysis of the VHL gene. Pathol Res Pract 2018; 214:1156-1165. [PMID: 29941223 DOI: 10.1016/j.prp.2018.05.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 05/03/2018] [Accepted: 05/05/2018] [Indexed: 10/16/2022]
Abstract
Less than 250 extraneuraxial hemangioblastomas occurring in paraneuraxial or peripheral sites have been reported to date, sporadically or in the setting of von Hippel-Lindau disease. Seventeen such cases underwent molecular genetic analysis, using either the patient's peripheral blood in 9 cases or paraffin embedded tumor tissue in the rest. VHL gene mutations were documented in 3/9 cases in which DNA from peripheral blood lymphocytes was used, all with clinically manifest von Hippel-Lindau disease; instead, no VHL gene alterations were found in all of the 8 cases with sporadic extraneuraxial hemangioblastoma in which DNA from tumor tissue was analyzed. Our aim is to investigate the molecular genetic profile of the VHL gene in extraneuraxial hemangioblastoma using paraffin embedded tumor tissues. The clinical features, histopathology, and molecular investigations of 10 extraneuraxial hemangioblastomas (7 females, 3 males; median age: 47 years) are presented herein. The histopathologic diagnosis was supported by immunohistochemistry (10/10) and electron microscopy (4/10). Molecular genetic analysis was conducted (10/10) for VHL gene mutations, LOH, and gene promoter methylation. Two of the present cases were already published with only limited or no molecular investigations. Four tumors of the present series were paraneuraxial, and 6 peripheral (2 involved soft tissues, and 4 the kidney). One tumor was von Hippel-Lindau disease-associated, 1 was classified as "hemangioblastoma-only VHLD", 7 were sporadic, and one was unknown. All were histopathologically analogous to their counterpart located inside the central nervous system. Immunophenotypically, all tumors expressed vimentin, S-100, NSE, and alpha-inhibin (10/10). Ultrastructurally, unbound lipid droplets filled the cytoplasms of the stromal cells. Molecular analysis revealed 3 inactivating mutations (1 germline, two somatic) in the coding sequence of the VHL gene in 2 different extraneuraxial hemangioblastomas, and LOH in 4 (two as a double hit), all non-renal extraneuraxial hemangioblastomas. Methylation analysis failed to disclose promoter methylation in any case. In conclusion, we report eight new cases from the wide category of extraneuraxial hemangioblastomas (4 paraneuraxial, and 4 renal), one of which was von Hippel-Lindau disease-associated and 7 sporadic. VHL gene alterations were found not only in the von Hippel-Lindau disease-associated tumor, but - for the first time - also in 3 sporadic ones, two of which with novel mutations.
Collapse
Affiliation(s)
- Lucia Anna Muscarella
- Laboratory of Oncology, IRCCS "Casa Sollievo della Sofferenza" Hospital, San Giovanni Rotondo, FG, Italy.
| | - Michele Bisceglia
- Anatomic Pathology, School of Biomedical Sciences, Etromapmax Pole, Lesina, FG, Italy.
| | - Carlos A Galliani
- Department of Pathology, Children's Minnesota, Minneapolis & St. Paul, MN, USA.
| | - Nina Zidar
- Institute of Pathology, Medical Faculty, University of Ljubliana, Ljubliana, Slovenia.
| | | | - Gianandrea Pasquinelli
- Department of Hemathology, Oncology and Clinical Pathology, "S. Orsola" Polyclinic, University of Bologna, Bologna, Italy.
| | - Annamaria la Torre
- Laboratory of Oncology, IRCCS "Casa Sollievo della Sofferenza" Hospital, San Giovanni Rotondo, FG, Italy.
| | - Angelo Sparaneo
- Laboratory of Oncology, IRCCS "Casa Sollievo della Sofferenza" Hospital, San Giovanni Rotondo, FG, Italy.
| | - Julie C Fanburg-Smith
- Department of Pathology, Penn State Health/Milton S Hershey Medical Center, Hershey, PA, USA.
| | - Janez Lamovec
- Department of Pathology, Institute of Oncology, Ljubljana, Slovenia.
| | - Michal Michal
- Department of Pathology, Charles University Medical Faculty Hospital, Plzen, Czech Republic.
| | | |
Collapse
|
9
|
Ma D, Yang J, Wang Y, Huang X, Du G, Zhou L. Whole exome sequencing identified genetic variations in Chinese hemangioblastoma patients. Am J Med Genet A 2017; 173:2605-2613. [PMID: 28742274 DOI: 10.1002/ajmg.a.38350] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 06/05/2017] [Accepted: 06/09/2017] [Indexed: 02/04/2023]
Abstract
Hemangioblastomas (HBs) are uncommon tumors characterized by the presence of inactivating alterations in the von Hippel-Lindau (VHL) gene in inherited cases and by infrequent somatic mutation in sporadic entities. We performed whole exome sequencing on 11 HB patients to further elucidate the genetics of HBs. A total of 270 somatic variations in 219 genes, of which there were 86 mutations in 67 genes, were found in sporadic HBs, and 184 mutations were found in 154 genes in familial HBs. C: G>T: A and T: A>C: G mutations are relatively common in most HB patients. Genes harboring the most significant mutations include PCDH9, KLHL12, DCAF4L1, and VHL in sporadic HBs, and ZNF814, DLG2, RIMS1, PNN, and MUC7 in familial HBs. The frequency of CNV varied considerably within sporadic HBs but was relatively similar within familial HBs. Five genes, including OTOGL, PLCB4, SCEL, THSD4, and WWOX, have CNVs in the six patients with sporadic HBs, and three genes, including ABCA6, CWC27, and LAMA2, have CNVs in the five patients with familial HBs. We found new genetic mutations and CNVs that might be involved in HBs; these findings highlight the complexity of the tumorigenesis of HBs and pinpoint potential therapeutic targets for the treatment of HBs.
Collapse
Affiliation(s)
- Dexuan Ma
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Jingyun Yang
- School of Economics, Shanghai University, Shanghai, China.,Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, Illinois.,Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois
| | - Ying Wang
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Xiang Huang
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Guhong Du
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Liangfu Zhou
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| |
Collapse
|
10
|
Pierscianek D, Wolf S, Keyvani K, El Hindy N, Stein KP, Sandalcioglu IE, Sure U, Mueller O, Zhu Y. Study of angiogenic signaling pathways in hemangioblastoma. Neuropathology 2016; 37:3-11. [PMID: 27388534 DOI: 10.1111/neup.12316] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/16/2016] [Accepted: 05/22/2016] [Indexed: 01/30/2023]
Abstract
Hemangioblastoma (HB) is mainly located in the brain and the spinal cord. The tumor is composed of two major components, namely neoplastic stromal cells and abundant microvessels. Thus, hyper-vascularization is the hallmark of this tumor. Despite the identification of germline and/or epigenetic mutations of Von Hippel Lindau (VHL) gene as an important pathogenic mechanism of HB, little is known about the molecular signaling involved in this highly vascularized tumor. The present study investigated the key players of multiple angiogenic signaling pathways including VEGF/VEGFR2, EphB4/EphrinB2, SDF1α/CXCR4 and Notch/Dll4 pathways in surgical specimens of 22 HB. The expression of key angiogenic factors was detected by RT2 -PCR and Western blot. Immunofluorescent staining revealed the cellular localization of these proteins. We demonstrated a massive upregulation of mRNA levels of VEGF and VEGFR2, CXCR4 and SDF1α, EphB4 and EphrinB2, as well as the main components of Dll4-Notch signaling in HB. An increase in the protein expression of VEGF, CXCR4 and the core-components of Dll4-Notch signaling was associated with an activation of Akt and Erk1/2 and accompanied by an elevated expression of PCNA. Immuofluorescent staining revealed the expression of VEGF and CXCR4 in endothelial cells as well as in tumor cells. Dll4 protein was predominantly found in tumor cells, whereas EphB4 immunoreactivity was exclusively detected in endothelial cells. We conclude that multiple key angiogenic pathways were activated in HB, which may synergistically contribute to the abundant vascularization in this tumor. Identification of these aberrant pathways provides potential targets for a possible future application of anti-angiogenic therapy for this tumor, particularly when a total surgical resection becomes difficult due to the localization or multiplicity of the tumor.
Collapse
Affiliation(s)
| | - Stefanie Wolf
- Department of Neurosurgery, Universitatsklinikum Essen, Germany
| | - Kathy Keyvani
- Institute of Neuropathology, University Hospital Essen, Essen, Germany
| | | | - Klaus-Peter Stein
- Department of Neurosurgery, KRH Hospital Nordstadt, Hannover, Germany
| | | | - Ulrich Sure
- Department of Neurosurgery, Universitatsklinikum Essen, Germany
| | - Oliver Mueller
- Department of Neurosurgery, Universitatsklinikum Essen, Germany
| | - Yuan Zhu
- Department of Neurosurgery, Universitatsklinikum Essen, Germany
| |
Collapse
|