scholarly journals Inactivation of the Arylhydrocarbon Receptor Nuclear Translocator (Arnt) Suppresses von Hippel-Lindau Disease-Associated Vascular Tumors in Mice

2005 ◽  
Vol 25 (8) ◽  
pp. 3163-3172 ◽  
Author(s):  
Erinn B. Rankin ◽  
Debra F. Higgins ◽  
Jacqueline A. Walisser ◽  
Randall S. Johnson ◽  
Christopher A. Bradfield ◽  
...  

ABSTRACT Patients with germ line mutations in the VHL tumor suppressor gene are predisposed to the development of highly vascularized tumors within multiple tissues. Loss of pVHL results in constitutive activation of the transcription factors HIF-1 and HIF-2, whose relative contributions to the pathogenesis of the VHL phenotype have yet to be defined. In order to examine the role of HIF in von Hippel-Lindau (VHL)-associated vascular tumorigenesis, we utilized Cre-loxP-mediated recombination to inactivate hypoxia-inducible factor-1α (Hif-1α) and arylhydrocarbon receptor nuclear translocator (Arnt) genes in a VHL mouse model of cavernous liver hemangiomas and polycythemia. Deletion of Hif-1α did not affect the development of vascular tumors and polycythemia, nor did it suppress the increased expression of vascular endothelial growth factor (Vegf) and erythropoietin (Epo). In contrast, phosphoglycerokinase (Pgk) expression was substantially decreased, providing evidence for target gene-dependent functional redundancy between different Hif transcription factors. Inactivation of Arnt completely suppressed the development of hemangiomas, polycythemia, and Hif-induced gene expression. Here, we demonstrate genetically that the development of VHL-associated vascular tumors in the liver depends on functional ARNT. Furthermore, we provide evidence that individual HIF transcription factors may play distinct roles in the development of specific VHL disease manifestations.

2007 ◽  
Vol 27 (15) ◽  
pp. 5381-5392 ◽  
Author(s):  
Lianjie Li ◽  
Liang Zhang ◽  
Xiaoping Zhang ◽  
Qin Yan ◽  
Yoji Andrew Minamishima ◽  
...  

ABSTRACT Clear cell carcinoma of the kidney is a major cause of mortality in patients with von Hippel-Lindau (VHL) disease, which is caused by germ line mutations that inactivate the VHL tumor suppressor gene. Biallelic VHL inactivation, due to mutations or hypermethylation, is also common in sporadic clear cell renal carcinomas. The VHL gene product, pVHL, is part of a ubiquitin ligase complex that targets the alpha subunits of the heterodimeric transcription factor hypoxia-inducible factor (HIF) for destruction under well-oxygenated conditions. All VHL mutations linked to classical VHL disease compromise this pVHL function although some missense mutations result in a low risk of kidney cancer (type 2A VHL disease) while others result in a high risk (type 2B VHL disease). We found that type 2A mutants were less defective than type 2B mutants when reintroduced into VHL −/− renal carcinoma cells with respect to HIF regulation. A stabilized version of HIF2α promoted tumor growth by VHL −/− cells engineered to produce type 2A mutants, while knock-down of HIF2α in cells producing type 2B mutants had the opposite effect. Therefore, quantitative differences with respect to HIF deregulation are sufficient to account for the differential risks of kidney cancer linked to VHL mutations.


2015 ◽  
Vol 139 (2) ◽  
pp. 263-268 ◽  
Author(s):  
Clarissa Cassol ◽  
Ozgur Mete

von Hippel–Lindau (VHL) disease is an autosomal dominant disorder caused by heterozygous mutations in the VHL tumor suppressor gene that is characterized by the occurrence of multiple endocrine and nonendocrine lesions. This review focuses on the endocrine manifestations of VHL disease. Pancreatic neuroendocrine proliferations (ductuloinsular complexes, islet dysplasia, endocrine microadenoma, and neuroendocrine tumors), pheochromocytomas, and extra-adrenal paragangliomas are important endocrine manifestations of VHL disease. They frequently display characteristic clinical, biochemical, and histopathologic features that, although not pathognomonic, can be helpful in suggesting VHL disease as the underlying etiology and distinguishing these tumors from sporadic cases. Recent improvements in treatment and outcomes of renal cell carcinomas have allowed pancreatic neuroendocrine tumors to emerge as a significant source of metastatic disease, making the accurate recognition and classification of these neoplasms by the pathologist of utmost importance to determine prognosis, treatment, and follow-up strategies for affected patients.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4345-4345
Author(s):  
Yongli Guan ◽  
John K. Wu ◽  
Wasil Jastaniah ◽  
Larry G. Moss ◽  
Colleen Digman ◽  
...  

Abstract We report three patients, two females and one male, with congenital polycythemia and high erythropoietin. All were extensively investigated in childhood; no known polycythemic conditions were diagnosed nor were any tumors known to be associated with polycythemia uncovered. At the ages of 14, 16, and 32 years the patients developed malignant hypertension secondary to multiple paragangliomas. In addition, one of patients has also developed a malignant pancreatic carcinoid tumor that expressed somatostatin. After the surgical resection of paragangliomas, hypertension subsided, but polycythemia persisted in all three subjects. Comprehensive screening for germ-line mutations of von Hippel-Lindau (VHL) gene as well as genes known to be causing familial paragangliomas - catalytic succinate dehydrogenase subunits B (SDHB), and catalytic succinate dehydrogenase subunit D (SDHD), has not revealed any mutations. In one of these patients studied so far there was no abnormality of the any of the three hypoxia control associated proline hydroxylase genes expressions found. Unlike the erythroid progenitors of Chuvash Polycythemia, these patients had normal sensitivity of erythroid progenitors to erythropoietin. The search for somatic mutations of VHL, SDHB, and SDHD genes, as well as quantitative analysis of the expressions of hypoxia inducible factor 1 alpha subunit (HIF-1a), vascular endothelial growth factor (VEGF), VHL, SDHB, and SDHD mRNAs by real-time PCR is ongoing. In summary, we report a new polycythemic syndrome of congenital polycythemia with high erythropoietin and the normal sensitivity of erythroid progenitors to erythropoietin, which is not associated with VHL mutation. This is in contrast to our previous experience with about 200 patients, homozygous for Chuvash Polycythemia mutation or compound heterozygous for Chuvash Polycythemia R200W and other VHL mutations, who have not developed paraganglioma or any VHL syndrome tumors. This new polycythemic syndrome shares some clinical features with both von Hippel Lindau syndrome and with the Chuvash polycythemia. While its molecular defect is yet to be elucidated, it is a distinct clinical and genetic entity.


2019 ◽  
Vol 104 (9) ◽  
pp. 3826-3834 ◽  
Author(s):  
Shahida K Flores ◽  
Ziming Cheng ◽  
Angela M Jasper ◽  
Keiko Natori ◽  
Takahiro Okamoto ◽  
...  

Abstract Context von Hippel-Lindau (VHL) disease, comprising renal cancer, hemangioblastoma, and/or pheochromocytoma (PHEO), is caused by missense or truncating variants of the VHL tumor-suppressor gene, which is involved in degradation of hypoxia-inducible factors (HIFs). However, the role of synonymous VHL variants in the disease is unclear. Objective We evaluated a synonymous VHL variant in patients with familial PHEO or VHL disease without a detectable pathogenic VHL mutation. Design We performed genetic and transcriptional analyses of leukocytes and/or tumors from affected and unaffected individuals and evaluated VHL splicing in existing cancer databases. Results We identified a synonymous VHL variant (c.414A>G, p.Pro138Pro) as the driver event in five independent individuals/families with PHEOs or VHL syndrome. This variant promotes exon 2 skipping and hence, abolishes expression of the full-length VHL transcript. Exon 2 spans the HIF-binding domain required for HIF degradation by VHL. Accordingly, PHEOs carrying this variant display HIF hyperactivation typical of VHL loss. Moreover, other exon 2 VHL variants from the The Cancer Genome Atlas pan-cancer datasets are biased toward expression of a VHL transcript that excludes this exon, supporting a broader impact of this spliced variant. Conclusion A recurrent synonymous VHL variant (c.414A>G, p.Pro138Pro) confers susceptibility to PHEO and VHL disease through splice disruption, leading to VHL dysfunction. This finding indicates that certain synonymous VHL variants may be clinically relevant and should be considered in genetic testing and surveillance settings. The observation that other coding VHL variants can exclude exon 2 suggests that dysregulated splicing may be an underappreciated mechanism in VHL-mediated tumorigenesis.


1997 ◽  
Vol 17 (9) ◽  
pp. 5629-5639 ◽  
Author(s):  
D Mukhopadhyay ◽  
B Knebelmann ◽  
H T Cohen ◽  
S Ananth ◽  
V P Sukhatme

The von Hippel-Lindau tumor suppressor gene (VHL) has a critical role in the pathogenesis of clear-cell renal cell carcinoma (RCC), as VHL mutations have been found in both von Hippel-Lindau disease-associated and sporadic RCCs. Recent studies suggest that vascular endothelial growth factor (VEGF) mRNA is upregulated in RCC- and von Hippel-Lindau disease-associated tumors. We have therefore assessed the effect of the VHL gene product on VEGF expression. VEGF promoter-luciferase constructs were transiently cotransfected with a wild-type VHL (wt-VHL) vector in several cell lines, including 293 embryonic kidney and RCC cell lines. wt-VHL protein inhibited VEGF promoter activity in a dose-dependent manner up to 5- to 10-fold. Deletion analysis defined a 144-bp region of the VEGF promoter necessary for VHL repression. This VHL-responsive element is GC rich and specifically binds the transcription factor Sp1 in crude nuclear extracts. In Drosophila cells, cotransfected VHL represses Sp1-mediated activation but not basal activity of the VEGF promoter. We next demonstrated in coimmunoprecipitates that VHL and Sp1 were part of the same complex and, by using a glutathione-S-transferase-VHL fusion protein and purified Sp1, that VHL and Sp1 directly interact. Furthermore, endogenous VEGF mRNA levels were suppressed in permanent RCC cell lines expressing wt-VHL, and nuclear run-on studies indicated that VHL regulation of VEGF occurs at least partly at the transcriptional level. These observations support a new mechanism for VHL-mediated transcriptional repression via a direct inhibitory action on Sp1 and suggest that loss of Sp1 inhibition may be important in the pathogenesis of von Hippel-Lindau disease and RCC.


2019 ◽  
Vol 4 (1) ◽  
pp. e000203 ◽  
Author(s):  
Beatriz González-Rodríguez ◽  
Karina Villar Gómez de las Heras ◽  
Daniel T Aguirre ◽  
Luis Rodríguez-Padial ◽  
Virginia Albiñana ◽  
...  

Backgroundvon Hippel-Lindau disease (VHL) is a multisystem cancer syndrome caused by mutations in the VHL gene. Retinal hemangioblastoma is one of the most common tumours, and when it appears near the optic nerve, its treatment is challenging and risky. To date, no treatment has proven effective in changing the course of the disease. This study was designed to evaluate the safety and effectiveness of propranolol in controlling these tumours.MethodsSeven patients were included. All patients took a daily dose of 120 mg of propranolol for 1 year. Clinical variables were assessed at baseline, and at 1, 3, 6, 9 and 12 months. The primary endpoint of the study was the number and size of retinal hemangioblastomas. On every visit, retinal outcomes and blood biomarkers (such as vascular endothelial growth factor (VEGF) and miR210) were analysed.ResultsNumber and size of retinal hemangioblastomas remained stable in all patients. All of them had initially increased levels of VEGF and miR210. There was a gradual reabsorption of retinal exudation in two patients, correlating with a progressive decrease of both biomarkers. The only adverse effect reported was hypotension in one patient.ConclusionsPropranolol could be used to treat retinal hemangioblastomas in VHL patients, although more studies are needed to determine the ideal dose and long-term effect. VEGF and miR210 should be explored as biomarkers of disease activity. As far as we know, these are the first biomarkers proposed to monitor the VHL disease activity.Trial registration number2014-003671-30


2019 ◽  
Vol 25 (8) ◽  
pp. 2049-2051 ◽  
Author(s):  
Derya Kıvrak Salim

Hemangioblastomas of central nervous system are rare and indolent. Twenty-five percent of cases are in association with von Hippel–Lindau disease. Surgery is the standard therapy but un-resectable or recurrent cases need radiation or systemic therapy. Defective von Hippel–Lindau tumor suppressor gene leads to vascular endothelial growth factor overexpression and enhance angiogenesis. Here we report a 19-year-old male, diagnosed at pediatric age, who had retinal and spinal cord hemangioblastomas. He was treated 34 months with bevacizumab, afterwards 12 months with thalidomide and tertiary therapy with pazopanib for 9 months which still goes on. In case of need, radiation and surgical procedures were performed. Vascular endothelial growth factor inhibition continuity is a good therapeutic option, which improves outcomes of von Hippel–Lindau-related hemangioblastomas.


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