scholarly journals Playing Tag with HIF: The VHL Story

2002 ◽  
Vol 2 (3) ◽  
pp. 131-135 ◽  
Author(s):  
Sherri K. Leung ◽  
Michael Ohh
Keyword(s):  
Ubiquitin Ligase ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Hypoxia Inducible Factor ◽  
E3 Ubiquitin Ligase ◽  
Suppressor Gene ◽  
Tumour Suppressor Gene ◽  
Matrix Assembly ◽  
Von Hippel Lindau ◽  
Ubiquitin Ligase Complex

Inactivation of the von Hippel-Lindau (VHL) tumour suppressor gene product pVHL is the cause of inherited VHL disease and is associated with sporadic kidney cancer. pVHL is found in a multiprotein complex with elongins B/C, Cul2, and Rbx1 forming an E3 ubiquitin ligase complex called VEC. This modular enzyme targets theαsubunits of hypoxia-inducible factor (HIF) for ubiquitin-mediated destruction. Consequently, tumour cells lacking functional pVHL overproduce the products of HIF-target genes such as vascular endothelial growth factor (VEGF), which promotes angiogenesis. This likely accounts for the hypervascular nature of VHL-associated neoplasms. Although pVHL has been linked to the cell-cycle, differentiation, and the regulation of extracellular matrix assembly, microenvironment pH, and tissue invasiveness, this review will focus on the recent insights into the molecular mechanisms governing the E3 ubiquitin ligase function of VEC.

Role of the VHL (von Hippel–Lindau) gene in renal cancer: a multifunctional tumour suppressor

2008 ◽  
Vol 36 (3) ◽  
pp. 472-478 ◽  
Author(s):  
Michelle J. Nyhan ◽  
Gerald C. O'Sullivan ◽  
Sharon L. McKenna
Keyword(s):  
Target Genes ◽  
Hypoxia Inducible Factor ◽  
Suppressor Gene ◽  
Tumour Suppressor Gene ◽  
Tumour Suppressor ◽  
Current Evidence ◽  
Von Hippel Lindau ◽  
Ubiquitin Ligase Complex ◽  
Protein Functions ◽  
Factor Α

The VHL (von Hippel–Lindau) tumour-suppressor gene is inactivated in VHL disease and in sporadic cases of CCRCC [clear-cell RCC (renal cell carcinoma)]. pVHL (VHL protein) functions as part of an E3 ubiquitin ligase complex that targets proteins for proteasomal degradation. The best-characterized substrate is HIF-α (hypoxia-inducible factor-α). Loss of pVHL and subsequent up-regulation of HIF target genes has been attributed to the highly vascular nature of these neoplasms. However, pVHL does not just function as the executioner of HIF-α. Additional functions of pVHL that may be important in preventing CCRCC tumorigenesis have been identified, including primary cilium maintenance, assembly of the extracellular matrix and roles in the stabilization of p53 and Jade-1 (gene for apoptosis and differentiation in epithelia). Current evidence indicates that pVHL probably requires additional co-operating signalling pathways for CCRCC initiation and tumorigenesis.

The role of von Hippel-Lindau tumor suppressor protein and hypoxia in renal clear cell carcinoma

2004 ◽  
Vol 287 (1) ◽  
pp. F1-F6 ◽  
Author(s):  
Roxana I. Sufan ◽  
Michael A. S. Jewett ◽  
Michael Ohh
Keyword(s):  
Tumor Suppressor ◽  
Molecular Mechanisms ◽  
Clear Cell ◽  
Hypoxia Inducible Factor ◽  
Suppressor Gene ◽  
Renal Clear Cell Carcinoma ◽  
Von Hippel Lindau ◽  
Ubiquitin Ligase Complex ◽  
Vhl Protein

The majority of kidney cancers are caused by the mutation of the von Hippel-Lindau ( VHL) tumor suppressor gene. VHL protein (pVHL) is part of an E3 ubiquitin ligase complex called VEC that is composed of elongin B, elongin C, cullin 2, NEDD8, and Rbx1. VEC targets a hypoxia-inducible factor (HIF) transcription factor for ubiquitin-mediated destruction selectively in the presence of oxygen. In the absence of wild-type pVHL, as in VHL patients or in the majority of sporadic clear cell renal cell carcinomas, HIF-responsive genes are inappropriately activated even under normoxia. Recent insights into the molecular mechanisms regulating the function of pVHL, and thereby HIF, in the context of kidney cancer are the focus of this review.

scholarly journals MiR-486-5p Suppresses Proliferation and Migration of Hepatocellular Carcinoma Cells through Downregulation of the E3 Ubiquitin Ligase CBL

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Jia He ◽  
Bin Xiao ◽  
Xiaoyan Li ◽  
Yongyin He ◽  
Linhai Li ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Lines ◽  
Ubiquitin Ligase ◽  
Target Genes ◽  
E3 Ubiquitin Ligase ◽  
Tumor Stage ◽  
Suppressor Gene ◽  
Cell Counting ◽  
And Migration ◽  
Proliferation And Migration

MicroRNAs have been broadly implicated in cancer, but precise functions and mechanisms in carcinogenesis vary among cancer types and in many cases remain poorly understood. Hepatocellular carcinoma (HCC) is among the most frequent and lethal cancers. The aim of the present study was to investigate the role of miR-486-5p in HCC and identify its specific target. MiR-486-5p was significantly downregulated in HCC tissues and cell lines compared with noncancerous tissues and, respectively, although expression level was not correlated with the degree of infiltration or tumor stage. However, miR-486-5p overexpression in HCC cells inhibited proliferation and migration as evidenced by CCK-8 cell counting, wound healing, and transwell assays, indicating that miR-486-5p is an HCC suppressor. We employed four miRNA databases to predict the target genes of miR-486-5p and verified retrieved genes using qPCR and western blotting. The E3 ubiquitin ligase CBL was significantly downregulated by miR-486-5p overexpression in HCC cell lines at both mRNA and protein level, and overexpression of CBL counteracted the inhibitory effects of miR-486-5p on HCC cell proliferation and migration. Moreover, CBL expression was negatively correlated with miR-486-5p expression in HCC tissues. Collectively, our results suggest that miR-486-5p may act as a tumor suppressor gene in HCC by downregulating CBL expression.

Role of VHL Gene Mutation in Human Cancer

2004 ◽  
Vol 22 (24) ◽  
pp. 4991-5004 ◽  
Author(s):  
William Y. Kim ◽  
William G. Kaelin
Keyword(s):  
Tumor Suppressor ◽  
Target Genes ◽  
Human Cancer ◽  
Critical Role ◽  
Hypoxia Inducible Factor ◽  
Suppressor Gene ◽  
Tumor Formation ◽  
Hereditary Cancer Syndrome ◽  
Cancer Syndrome ◽  
Von Hippel Lindau

Germline inactivation of the von Hippel-Lindau (VHL) tumor suppressor gene causes the von Hippel-Lindau hereditary cancer syndrome, and somatic mutations of this gene have been linked to the development of sporadic hemangioblastomas and clear-cell renal carcinomas. The VHL tumor suppressor protein (pVHL), through its oxygen-dependent polyubiquitylation of hypoxia-inducible factor (HIF), plays a central role in the mammalian oxygen-sensing pathway. This interaction between pVHL and HIF is governed by post-translational prolyl hydroxylation of HIF in the presence of oxygen by a conserved family of Egl-nine (EGLN) enzymes. In the absence of pVHL, HIF becomes stabilized and is free to induce the expression of its target genes, many of which are important in regulating angiogenesis, cell growth, or cell survival. Moreover, preliminary data indicate that HIF plays a critical role in pVHL-defective tumor formation, raising the possibility that drugs directed against HIF or its downstream targets (such as vascular endothelial growth factor) might one day play a role in the treatment of hemangioblastoma and renal cell carcinoma. On the other hand, clear genotype-phenotype correlations are emerging in VHL disease and can be rationalized if pVHL has functions separate from its control of HIF.

scholarly journals Multiple Splice Variants of the Human HIF-3α Locus Are Targets of the von Hippel-Lindau E3 Ubiquitin Ligase Complex

2003 ◽  
Vol 278 (13) ◽  
pp. 11032-11040 ◽  
Author(s):  
Mindy A. Maynard ◽  
Heng Qi ◽  
Jacky Chung ◽  
Eric H. L. Lee ◽  
Yukihiro Kondo ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Splice Variants ◽  
E3 Ubiquitin Ligase ◽  
Von Hippel Lindau ◽  
Ubiquitin Ligase Complex

Hypoxia-inducible factor prolyl 4-hydroxylases: common and specific roles

2013 ◽  
Vol 394 (4) ◽  
pp. 435-448 ◽  
Author(s):  
Johanna Myllyharju ◽  
Peppi Koivunen
Keyword(s):  
Target Genes ◽  
Hypoxia Inducible Factor ◽  
Drug Candidate ◽  
Hypoxia Response ◽  
Von Hippel Lindau ◽  
Ubiquitin Ligase Complex ◽  
Biological Studies ◽  
The Common

Abstract Hypoxia-inducible transcription factor (HIF), an αβ dimer, is the key inducer of hypoxia-responsive genes that operate both during normal development and pathological processes in association with decreased oxygen availability. The products of HIF target genes function in, e.g., hematopoiesis, angiogenesis, iron transport, glucose utilization, resistance to oxidative stress, cell proliferation, survival and apoptosis, extracellular matrix homeostasis, and tumorigenesis and metastasis. HIF is accumulated in hypoxia, whereas it is rapidly degraded in normoxic cells. The oxygen-sensing mechanism behind this phenomenon is provided by HIF prolyl 4-hydroxylases (HIF-P4Hs, commonly known as PHDs and EglNs) that require oxygen in their reaction. In normoxia, two prolines in the oxygen-dependent degradation domain of the HIFα subunit become hydroxylated by the HIF-P4Hs. The 4-hydroxyproline residues formed serve as recognition sites for the von Hippel-Lindau E3 ubiquitin ligase complex and result in subsequent ubiquitination and instant proteasomal degradation of HIFα in normoxia. The HIF-P4H reaction is inhibited in hypoxia. HIFα evades degradation and forms a functional dimer with HIFβ, leading to activation of the HIF target genes. The central role of HIF-P4Hs in the regulation of the hypoxia response pathway has provided an attractive possibility as a drug candidate for treatment of, e.g., severe anemias and ischemic conditions, and several companies are currently carrying out clinical studies on the use of HIF-P4H inhibitors to treat anemia in patients with a kidney disease. Therefore, it is important to understand the effects of individual HIF-P4H isoenzymes on the hypoxia response and potential other pathways in vivo. The common and specific functions of the HIF-P4H isoenzymes are discussed in this review on the basis of available data from cell biological studies and gene-modified animals.

scholarly journals pVHL Modification by NEDD8 Is Required for Fibronectin Matrix Assembly and Suppression of Tumor Development

2004 ◽  
Vol 24 (8) ◽  
pp. 3251-3261 ◽  
Author(s):  
Natalie H. Stickle ◽  
Jacky Chung ◽  
Jeffery M. Klco ◽  
Richard P. Hill ◽  
William G. Kaelin ◽  
...  
Keyword(s):  
Hypoxia Inducible Factor ◽  
Tumor Development ◽  
Three Dimensional ◽  
Suppressor Gene ◽  
Matrix Assembly ◽  
Von Hippel Lindau ◽  
Fibronectin Matrix ◽  
Matrix Expression ◽  
Vhl Disease ◽  
Hif Pathway

ABSTRACT Functional inactivation of the von Hippel-Lindau (VHL) tumor suppressor gene is the cause of the familial VHL disease and most sporadic renal clear-cell carcinomas (RCC). pVHL has been shown to play a role in the destruction of hypoxia-inducible factor α (HIF-α) subunits via ubiquitin-mediated proteolysis and in the regulation of fibronectin matrix assembly. Although most disease-causing pVHL mutations hinder the regulation of the HIF pathway, every disease-causing pVHL mutant tested to date has failed to promote the assembly of the fibronectin matrix, underscoring its potential importance in VHL disease. Here, we report that a ubiquitin-like molecule called NEDD8 covalently modifies pVHL. A nonneddylateable pVHL mutant, while retaining its ability to ubiquitylate HIF, failed to bind to and promote the assembly of the fibronectin matrix. Expression of the neddylation-defective pVHL in RCC cells, while restoring the regulation of HIF, failed to promote the differentiated morphology in a three-dimensional growth assay and was insufficient to suppress the formation of tumors in SCID mice. These results suggest that NEDD8 modification of pVHL plays an important role in fibronectin matrix assembly and that in the absence of such regulation, an intact HIF pathway is insufficient to prevent VHL-associated tumorigenesis.

scholarly journals The von Hippel-Lindau Protein pVHL Inhibits Ribosome Biogenesis and Protein Synthesis

2013 ◽  
Vol 288 (23) ◽  
pp. 16588-16597 ◽  
Author(s):  
Wen-Ting Zhao ◽  
Cheng-Fu Zhou ◽  
Xue-Bing Li ◽  
Yun-Fang Zhang ◽  
Li Fan ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Tumor Suppressor ◽  
Ribosome Biogenesis ◽  
Hypoxia Inducible Factor ◽  
Suppressor Gene ◽  
Nuclear Retention ◽  
Von Hippel Lindau ◽  
Ubiquitin Ligase Complex ◽  
Ribosomal Protein S3 ◽  
Factor Α

pVHL, the product of von Hippel-Lindau (VHL) tumor suppressor gene, functions as the substrate recognition component of an E3-ubiquitin ligase complex that targets hypoxia inducible factor α (HIF-α) for ubiquitination and degradation. Besides HIF-α, pVHL also interacts with other proteins and has multiple functions. Here, we report that pVHL inhibits ribosome biogenesis and protein synthesis. We find that pVHL associates with the 40S ribosomal protein S3 (RPS3) but does not target it for destruction. Rather, the pVHL-RPS3 association interferes with the interaction between RPS3 and RPS2. Expression of pVHL also leads to nuclear retention of pre-40S ribosomal subunits, diminishing polysomes and 18S rRNA levels. We also demonstrate that pVHL suppresses both cap-dependent and cap-independent protein synthesis. Our findings unravel a novel function of pVHL and provide insight into the regulation of ribosome biogenesis by the tumor suppressor pVHL.

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