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FEBS Lett. Author manuscript; available in PMC 2013 June 4.
Published in final edited form as:
PMCID: PMC3372859

Systemic VHL gene functions and the VHL disease


The von Hippel-Lindau tumor suppressor gene (VHL) is best known as an E3 ubiquitin ligase that negatively regulates the hypoxia inducible factor (HIF). VHL mutations are the genetic defects underlying several human diseases including polycythemia, familial VHL tumor syndrome and sporadic renal cell carcinoma. VHL mutations can lead to cell-autonomous phenotypes in the tumor cells. However, non-tumor cell-autonomous functions of VHL have also been noted. VHL tumor-derived cytokines can promote inflammation and induce mobilization of endothelial progenitor cells. Up-regulation of HIF caused by VHL loss-of-function mutants, including heterozygotes, has been shown to increase the activities of hematopoietic stem cells, endothelial cells and myeloid cells. As such, systemic functions of VHL likely play important roles in the development of VHL disease.

Keywords: Erythropoietin, Hematopoiesis, Hemangioblastoma, Haploid insufficiency, Inflammation


The von Hippel-Lindau tumor suppressor gene (VHL) encodes a multifunctional protein, the mutations of which underlie the genetic defect in the familial VHL disease. Germ line mutations in VHL predispose the patients to several highly vascularized benign and malignant tumors, including renal cell carcinoma of the clear-cell type (ccRCC), hemangioblastoma (HB) and pheochromocytoma (tumor in the adrenal glands). Less frequent VHL tumors include those in pancreas (pancreatic cysts, serous cystadenoma and pancreatic neuroendocrine tumors), inner ears (endolymphatic sac tumor) and testes (epididymal cystadenomas). In these tumors, the remaining wild-type allele is inactivated through somatic mutation. Biallelic loss of VHL function has also been found in a majority of the sporadic ccRCC [13]. The protein encoded by the VHL gene is best known as the substrate-binding subunit of an E3 ubiquitin ligase [48]. The best-known degradation target of VHL-containing E3 ligase is the α-subunit of hypoxia-inducible factor (HIF-α) in normal physiological conditions [9]. At normal oxygen level, HIF-α is hydroxylated at the proline residues within an oxygen-dependent degradation domain. The prolyl-hydroxylated HIF-α is recognized by VHL, leading to poly-ubiquitination and degradation. The hydroxylation reaction is mediated by the prolyl-hydroxylase domain proteins (PHDs) [10]. In hypoxic conditions, the prolyl-hydroxylases are inactive and HIF-α is stabilized. HIF-α then dimerizes with the β-subunit (HIF-β) and translocates to the nucleus where the dimer functions as a transcription factor. Its best-known target genes encode proteins involved in glycolysis (e.g., phosphoglycerate kinase), glucose transport (Glut-1), angiogenesis [vascular endothelial growth factor (VEGF)] and erythropoiesis (erythropoietin); that is, proteins that mediate the cellular response and adaptation to hypoxic conditions [11]. In addition, CXC chemokine receptor 4 (CXCR4) and the ligand stromal cell-derived factor (SDF)-1 were also identified as HIF targets [12, 13], which indicates that HIF activation may contribute to the metastatic potential of cancer cells. These functions support a critical role of VHL in regulating tumor progression, especially in hyper-vascularized tumors such as ccRCC and HB. However, accumulated evidence has indicated that many HIF-independent activities of VHL also exist [14, 15]. Some of these functions are mediated through stabilizing VHL targets, contrary to its known E3 ligase activity. Therefore, VHL is a multifunctional adaptor protein that, depending on the interacting partners, can promote protein degradation or serve as a chaperon. Some of these diverse activities likely also contribute significantly to the tumor suppressor and other physiological functions.

These diverse functions also suggest that there may not be a simple, unified pathophysiological mechanism that can explain the etiology of VHL diseases. Although cell-autonomous mechanisms in VHL mutant tumors might be explained by up-regulation of cyclin D1 [16], increased Akt-mTOR signaling [17, 18], elevated FGF receptor signaling [19, 20], disruption of cilia formation [2123], down-regulation of p53 [24], among others, it is also well established that VHL mutant cells secret a large repertoire of growth factors and cytokines, including erythropoietin (Epo), VEGF, TGF-β, PDGFβ, TNF-α, among many others [11]. Furthermore, in the last decade, it has become apparent that HIFs play a central role in the hematopoietic system [2528]. VHL mutations and the resulting HIF up-regulation therefore can impact many vasculo/hematopoietic lineages. Also interestingly, some of these abnormalities can occur in partial VHL loss-of-function mutants and in heterozygous mice and heterozygous immune cells from VHL patients [20, 29, 30]. During development, the Drosophila VHL gene also shows haploid insufficiency [31]. The haploid-insufficient function of VHL may be profoundly important in considering the etiology of VHL disease since all VHL patients are, by definition, VHL heterozygotes. Such understanding prompted the idea that a non-cell autonomous and systemic consideration of the VHL function in the context of VHL disease may need to be evaluated. This review examines the current knowledge in this regard. The role of VEGF and PDGFβ over-expression in VHL tumor angiogenesis is well known and will not be discussed herein.

1. VHL-associated polycythemia

A homozygous missense mutation in the VHL gene, first identified in the Chuvash region of Russia and called the Chuvash mutation (R200W), was linked to a familial form of polycythemia — overexpansion of erythrocytes [32]. Subsequently, a knockin R200W transgenic mouse and a zebrafish VHL null mutant also exhibited polycythemia [33, 34]. Erythropoiesis is regulated by Epo, and polycythemia can be caused by hypersensitivity to Epo (called primary polycythemia or polycythemia vera), or by overproduction of Epo (secondary polycythemia) [33, 35, 36]. Interestingly, VHL-associated polycythemia has features of both primary and secondary polycythemia [36]. Epo is normally produced by interstitial fibroblasts in the kidney [37, 38] and by perisinusoidal (Ito) cells in the liver [39]. HIF over-expression leads to up-regulation of Epo, not only in the normal Epo-producing cells but also in the VHL mutant tumor cells [4043]. However, erythrocyte progenitors harboring the R200W mutation are also more sensitive to Epo [33, 35, 36]. The mechanism of this hypersensitivity has been discovered only recently. The Epo receptor (EpoR) signals through the JAK-STAT pathway: upon ligand binding, the receptor-associated tyrosine kinase JAK2 is phosphorylated and in turn phosphorylates the transcription factor STAT5 [36, 44]. In a negative feedback loop, phosphorylated JAK2 (pJAK2) is targeted for proteasomal degradation by ubiquitination [44]. VHL was found to mediate pJAK2 polyubiquitination, and in polycythemia-associated VHL mutations, a failure to eliminate pJAK2, leading to prolonged JAK-STAT signaling, was observed [35]. This phenotype could be rescued both in vitro and in vivo by administration of the JAK2 inhibitor Tg101209, indicating that JAK2 inhibitors may prove useful in the treatment of polycythemia. Surprisingly, VHL-mediated pJAK ubiquitination did not require the formation of the well-characterized ElonginB/C-Cul2-VHL E3 ligase complex [5]. Instead, pJAK2 ubiquitination depended on the formation of a complex of pJAK2, SOCS1 and VHL. The presence of primary polycythemic phenotype also indicates that VHL mutant erythrocyte progenitors may be a contributing factor to the disease.

2. The role of Epo in angiogenesis and tumorigenesis

Polycythemia has been considered an isolated branch of the VHL syndrome, mainly because the Chuvash disease (R200W mutant) patients do not exhibit increased incidences of tumors [45]. This notion may need to be reconsidered, however, since Epo has been shown to have pleiotropic effects [46, 47], including a role in tumorigenesis. Epo signaling is not restricted to red blood cells. Also, the Epo/EpoR system is known to induce proliferation, chemotaxis, and angiogenesis, and inhibit apoptosis [46, 48, 49]. Epo has been found to exert a strong cyto-protective effect in animal models of brain, cardiac and renal ischemia [reviewed in (47)]. Epo signaling appears to inhibit apoptotic pathways triggered by ischemia, but may in addition reduce hypoxic injury by promoting angiogenesis. Epo administration to ischemic patients is therefore currently subject to clinical trials. Epo and EpoR are also expressed in various tumors including those of head-and-neck [50], breast, colon, lung, prostate [51], ovary [51, 52], uterine [52], kidney [40, 42, 43] and cervix [53], as well as neuroblastoma, astrocytoma, and other solid nervous system tumors [54], and numerous malignant cell lines [55, 56]. Epo added to cancer cell lines in vitro elicited secretion of angiogenic growth factors and promoted proliferation and chemotaxis of endothelial cells [54]. Neutralizing anti-Epo monoclonal antibody and soluble EpoR antagonist injected into ex vivo cultured tumor tissue blocked tumor growth [52] and soluble EpoR antagonist injected into mice carrying cancer cell xenografts reduced angiogenesis and tumor cell survival [55]. Furthermore, Epo pretreatment of some cancer cell lines rendered them less sensitive to the cytotoxic effects of the chemotherapy drug cisplatin [56]. Of note, polycythemic mice were shown to be iron deficient [57], most likely because the Epo-induced erythropoiesis led to an exhaustion of iron stores. Since iron is a necessary co-factor of proline hydroxylases, it is tempting to speculate that Epo-induced iron deficiency may be a mechanism by which tumors mediate systemic HIF up-regulation.

Interestingly, although full-blown polycythemia is infrequent in VHL disease, consistently elevated Epo is detected in a majority of VHL patients [58]. In addition, certain heterozygous VHL mutations can lead to polycythemia [5961]. There is also an established association between hemangioblastoma and polycythemia [62]. It is therefore conceivable that elevated Epo level in VHL patients, whether or not it manifests into polycythemia, may contribute to progression of various VHL tumors.

3. VHL and endothelial progenitor cells

Based on the observation that mononuclear cells isolated from bone marrow or peripheral blood can give rise to endothelial colonies, the existence of endothelial stem cells – called endothelial progenitors cells (EP or EPCs) or, if detected in the peripheral blood, circulating EPCs (CEP/CEPC) – has been postulated (reviewed in [63, 64]). Importantly, EPCs need to be distinguished from a subset of monocytes that express endothelial markers such as VEGFR1, VEGFR2, Tie2 and CD31. These monocytes are sometimes referred to as circulating angiogenic cells (CACs). CACs contribute to angiogenesis by releasing proangiogenic cytokines, but do not differentiate into endothelial cells; instead they differentiate into a subset of tumor promoting macrophages (discussed in section 5) [63, 65]. CACs and CEPCs are CD45 positive and negative, respectively.

It has been proposed that CEPCs may contribute to tumor angiogenesis, although this is still somewhat controversial (see for instance [48, 66]). Nevertheless, there is evidence that CEPCs are relevant to VHL tumors. Patients with ccRCC were found to have elevated levels of CEPCs [67]. In addition, high levels of VEGFR2-positive cells in the peripheral blood were found to correlate with a poor prognosis in ccRCC [68]. Interestingly, elevated CEPCs were also detected in a case of sporadic ccRCC caused by somatic VHL inactivation [69]. Therefore CEPC mobilization observed in VHL tumors may result from both intrinsically higher motility of the EPCs or from stimulation emanating from the VHL tumors. In the latter case, VHL tumors can induce CEPC mobilization through Epo [70], which is expressed by ccRCC [42, 43]. In addition, ccRCC can also induce the mobilization of VEGFR1+ CACs, at least in part through VEGF [71].

4. VHL, HIF and the hematopoietic system

The role of HIF in the immune system has been extensively reviewed [2528, 72]. We will therefore summarize only some of the most recent findings and highlight papers that directly address the role of VHL.

In the last decade it has become evident that HIF, and in particular HIF-1α, regulates hematopoietic stem cells, and both innate and adaptive immune cells [2529, 72]. In contrast, the role of VHL in these cell lineages has been addressed only in a small number of studies. However, there is evidence that cells of the hematopoietic system are sensitive to even small changes in HIF-1α expression levels. Hence, in many cases, opposite phenotypes are observed in HIF-1α−/− and VHL−/− cells, and in some cases VHL haploinsufficiency is observed, with VHL+/− cells displaying a phenotype that is intermediate to that observed in HIF-1α−/− and VHL−/− cells [29, 30]. This is consistent with a model that implicates the importance of HIF-1α dosage: HIF-1α−/− cells display loss of function, VHL+/− cells intermediate gain-of-function due to moderate HIF-1α up-regulation, and VHL−/− cells hyper- or malfunctioning due to high-level HIF-1α over-expression.

It is now recognized that lymphatic organs as well as sites of inflammation are hypoxic [28, 29]. Cells of the hematopoietic system rely to a large extent on an anaerobic source of ATP: glycolysis [7375]. Since it is the master transcription factor of glycolysis related genes, HIF-1α plays a prominent role in many lineages of the hematopoietic system [28, 7375], and defects in HIF-1α deficient immune cells can be in part explained by decreased ATP levels [74]. Besides its role in regulating glycolysis, HIF-1α also regulates apoptosis, cell proliferation and differentiation of the hematopoietic lineages. For instance, it was recently shown that HIF-1α is necessary for the maintenance of quiescence in long-term hematopoietic stem cells (LT HPSC) [29]. In an induced conditional HIF-1α knockout (using Poly I:C induced Msx-Cre), LT HPSCs showed increased proliferation when experimentally challenged as well as upon aging. The increased proliferation led to senescence, and ultimately to an exhaustion of the LT HPSC pool. Consequently, HIF-1α−/− HPSCs failed to reconstitute the bone marrow in serial transplantations. In contrast, deletion of VHL in HPSCs led to increased quiescence and increased numbers of HPSCs, in particular LT-HPSCs. However, these VHL mutant HPSCs were not functional: they failed to reconstitute the bone marrow in transplantation experiments due to a combination of abnormal quiescence, homing defects and enhanced apoptosis [29]. The observed defects in VHL−/− HPSCs were HIF-1α dependent and cell autonomous. Interestingly, heterozygous VHL HPSC displayed an intermediate phenotype: deletion of one VHL allele led to increased quiescence and increased numbers of HPSCs; however, in contrast to VHL−/− HPSCs, VHL+/− HPSC were functional and reconstituted the bone marrow of lethally irradiated mice even more efficiently than wild-type HPSCs. Hence, HIF-1α levels in HPSCs are fine-tuned to maintain a balance between quiescence necessary for the maintenance of the HPSC pool, and proliferation necessary to replenish the hematopoietic system. The increased HPSC activity conferred by VHL heterozygosity may be a significant contributing factor in the progression of VHL disease, considering the hypervascularity associated with the VHL tumors and the potential contribution from inflammatory response (see below).

HIF-1α also plays an important role in lymphocytes. HIF-1α deficiency leads to an increase in B1 B cells, and a concomitant reduction in B2 B cells, the latter due to a lack of proliferation of pro-B cells [76]. The role of VHL in B cell differentiation has not been directly addressed, but epigenetic down-regulation of VHL has been recently reported in diffuse large B cell lymphoma and chronic lymphocytic leukemia [7780].

The role of HIF-1α in T cells differentiation and activation is somewhat controversial, although conflicting findings may be in part explained by distinct roles of HIF-1α in different T cell subsets and immature vs. mature T cells. Neumann and colleagues reported attenuated T cell receptor (TCR) signaling in VHL−/− T cells [81]. This effect was HIF-1α-dependent, since it was not observed in VHL−/− HIF-1α−/− T cells. Hence, HIF-α expression appears to regulate TCR signaling negatively. Consistent with this, deletion of VHL in the thymus led to increased apoptosis of T cells at the double positive stage (a stage at which T cells are positively selected for a functional TCR) [82], resulting in a decrease in mature T cells. Furthermore, HIF-1α−/− T cells were reported to produce more inflammatory mediators such as IFNγ and TNFα- than wild-type T cells when stimulated in vitro [83]. Also, mice in which HIF-1α was deleted in T cells showed improved survival of sepsis due to T cell activation [84]. In contrast to these findings, which indicate that HIF-1α negatively regulates T cell survival and activation, hypoxia induced HIF-1α was found to inhibit activation induced cell death (AICD) in T cells [85]. However, this protective effect may be also explained by attenuated TCR signaling, since AICD is TCR dependent. On the other hand, it is difficult to reconcile the anti-inflammatory effects of HIF-1α discussed above with the recent finding that HIF-1α is essential for the induction of Th17 cells, a pro-inflammatory CD4 T cell subset [86]. CD4 T cells can differentiate into either Th17 or Treg T cells, depending on the cytokine environment [87]. RORγt and Foxp3 are key transcription factors in Th17 and Treg differentiation, respectively, and Foxp3 also inhibits RORγt [87]. Dang and colleagues [86] showed that HIF-1α tips the balance towards Th17 differentiation by inducing RORγt. Consistent with these findings, mice in which HIF-1α was conditionally deleted in CD4 T cells had reduced numbers of Th17 cells and were protected from experimentally induced encephalitis (a model for autoimmune disease). Therefore, VHL+/− with moderate increase in HIF-1α can potentially promote Th17-mediated inflammatory response.

The role of HIF in the myeloid lineage was addressed using a lysozyme M driven Cre, which led to efficient deletion in both macrophages and neutrophils [72, 74]. In vivo experiments using these conditional knockout mice show that both HIF-1α and HIF-2α have essential roles in myeloid-mediated inflammation. Myeloid HIF deletion protected mice from inflammation induced by chemical irritation, experimentally induced autoimmune disease and LPS induced sepsis [72, 74]. Conversely, mice with myeloid HIF deletion were impaired in controlling bacterial infections [88]. These studies also showed that HIF-1α and HIF-2α have distinct, non-redundant roles in innate immunity. In myeloid cells, HIF-1α is needed for ATP generation, granzyme synthesis and iNOS/NO production, and, in neutrophils, protection from apoptosis, whereas HIF-2α mediates cytokine production and up-regulates chemokine receptors involved in macrophage migration [25, 26, 74, 88]. Consistent with HIF over-expression upon VHL deletion, HIF and VHL myeloid knockout resulted in opposite phenotypes both in vitro and in vivo [74]. VHL−/− macrophages produced more granzymes and iNOS/NO, and were more efficient than wild-type macrophages at lysing phagocytosed bacteria in vitro. Furthermore, in a phorbol ester induced ear inflammation model, mice with myeloid VHL deletion displayed a significantly enhanced inflammatory response, although it was not investigated whether this phenotype was solely due to HIF over-expression [74].

5. VHL, inflammation and cancer

Based on the observation that HIF is essential for myeloid and Th17-mediated inflammation, it is now thought that hypoxia is a strong pro-inflammatory cue for immune cells [2628, 86, 89]. Importantly, VHL haploinsufficiency, which is likely associated with partial up-regulation of HIF, is observed both in HPSCs and neutrophils (see above) [29, 30]. Also, in support of a link between VHL and inflammation, it has recently been reported that pulmonary hypertension, a complication of Chuvash polycythemia, is caused by lung fibrosis [90]. It is hence likely that the immune system of VHL heterozygous individuals is skewed towards the development of inflammatory responses. Such a pro-inflammatory environment may contribute to tumorigenesis. Tumor infiltrating macrophages, called tumor associated macrophages (TAMs), are thought to promote tumor growth by releasing pro-angiogenic and immunosuppressive cytokines. In support of this, a high degree of TAM infiltration correlates with poor prognosis in human cancers [65]. Nuclear HIF-2α was detected in TAMs of many human cancers [91], and conversely, myeloid HIF-2α deletion led to a reduction in TAM recruitment, and concomitantly, slower tumor growth [72]. It is tempting to speculate that VHL deletion (VHL−/− or VHL+/−) would lead conversely to faster tumor growth due to more efficient TAM recruitment and/or increased cytokine production by TAMs. However, alterations in other immune cells, such as Th17 T cells, could also promote tumorigenesis. It remains to be elucidated if immune cells contribute to the formation of tumors in VHL disease, and if so, which types of immune cells are relevant in this process.

Besides a direct role in the immune cells, VHL knockouts in mouse kidney epithelia have also been shown to induce an inflammatory response. A knockout strain specific for the podocyte in kidney exhibited glomerulomegaly and occasional glomerulosclerosis [92]. Interestingly, a Pepck-Cre driven (specific for proximal tubules) VHL knockout could be induced to develop renal fibrosis after subtotal nephrectomy of one kidney and complete removal of the other [93]. In addition, hypoxia and increased HIF-1α or HIF-2α activities have been linked to kidney fibrosis in mouse [94, 95]. VHL mutant ccRCC cells have been shown to over-produce such inflammatory cytokines as TNFα [96] and TGF-β [97], and to up-regulate NFkB [98, 99], the latter can in turn induce cytokine expression. The connection between VHL mutant cells and inflammation is worthy of more in-depth investigation, since prolonged inflammation can promote proliferation through the action of secreted cytokines, and importantly, can induce genetic changes in pre-cancerous cells by induction of reactive oxygen species or by oxidative inactivation of mismatch repair enzymes [100103].

6. VHL, glucose metabolism and insulin secretion

β-cells in the endocrine islets of the pancreas produce insulin and store it in secretory vesicels [104]. Glucose Stimulated Insulin Secretion (GSIS) is essential for glucose homeostasis and is induced by quantitative ATP generation after glucose uptake. A rise in the ATP/ADP ratio induces the closure of ATP sensitive KATP channels, leading to depolarization of the plasma membrane and Ca2+ influx. The Ca2+ influx in turn stimulates the excocytosis of insulin. Hence, insulin secretion is coupled to extracellular glucose concentration: a rise in extracellular glucose concentration results in increased intracellular ATP generation, and ultimately, in increased insulin secretion. Since HIF-1α up-regulation is known to affect glucose metabolism, the role of VHL in insulin-mediated glucose homeostasis has attracted extensive interest. β-cell (RIP2) or pan-pancreas (Pdx2) specific Cre mice have been used to delete VHL in β-cells [105109]. Several studies reported that gross morphology of the pancreas was unaffected by β-cells specific or pan-pancreatic VHL deletion [105108], although two studies suggested an age dependent decrease in β-cells [106, 107]. In contrast, a recent study reported development of precancerous lesions in pan-pancreatic VHL knockout mice, but not upon deletion of VHL in α-or β-cells [109]. These differences are at least in part due to differences in the mouse strains used in the studies (mixed C57BL/6 - Sv129 vs C57BL/6, BALB/C or A/J) [110]. Interestingly, the β-cells VHL knockout mice, but not the pan-pancreatic VHL knockout mice displayed also dwarfism [105, 107, 111]. Cantley and colleagues reported that the dwarfism was caused by RIP2-Cre activity in the hypothalamus, which led to reduced growth hormone (GH) production [105], whereas Shen and colleagues did not oberve a significant down-regulation of GH [109]. It is possible that these differences are due to the age at which the GH levels were assayed (3 months vs 6 monts). More importantly, several studies showed that VHL knockout in β-cells (pan-pancreatic or β-cell specific) led to impaired GSIS at high glucose concentrations (e.g., following glucose injection), and consequently glucose intolerance (impaired clearance of glucose from the blood), the hallmark of type-II diabetes [105, 106, 108]. Impaired GSIS and glucose intolerance were found to be HIF-1α dependent, since they were not observed in VHL and HIF-1α double β-cell knockout mice [105, 106]. In the cell, glucose can be used for aerobic or anaerobic ATP generation. In the aerobic pathway, glucose is processed to pyruvate, which is converted to acetyl-CoA and is channeled into the tricarboxy acid (TCA) cycle, generating electron donors for oxidative phosphorylation in mitochondria, with oxygen as the electron acceptor. In contrast, the less-efficient glycolytic ATP generation involves the processing of pyruvate to lactate. VHL deletion in β-cells led to HIF-1α-dependent upregulation of pyruvate dehydrogenase kinase 1 (PDK1), which inhibits the conversion of pyruvate to acetyl-CoA, preventing its entry into the TCA cycle, and Lactate dehydrogenase A (LDHA), which generates lactate from pyruvate. Hence, as described for other cell types, HIF-1α stabilization in β-cells induced a metabolic switch from ATP generation through oxidative phosphorylation to ATP generation through glycolysis. Although these studies disagreed on whether glucose uptake and basal insulin secretion were affected in VHL knockout cells, they demonstrated that the lack of oxidative glucose metabolism was the likely cause of the observed type-II diabetes phenotype. A link between VHL mutation and diabetes has not been established clinically. Nonetheless, the metabolic imbalance gleaned from the VHL functional studies may help clarify some aspects of the etiology of type-II diabetes. These models also serve as an in vivo confirmation of metabolic switch in the VHL mutant cells, which may be a relevant contributor to the suspected metabolic-stress-induced inflammatory response in cancer cells.

7. Hematopoietic stem cells, hemangioblastoma and VHL-associated extramedullary hematopoiesis

HB is a highly vascularized tumor of the central nervous system that affect the retina, cerebellum, brain stem and spinal cord [112]. Although HB is a benign tumor, it is typically associated with large peritumoral cysts, which cause morbidity and mortality by exerting pressure on the surrounding neuronal tissue [112114]. The exact etiology of HB is still unclear. HB consists of a vascular and a stromal component [112]. Somatic VHL inactivation was detected only in the stromal component [115117]. Hence, although they are sometimes described as such, HBs are not endothelial tumors; rather, the overgrowth of endothelium is caused, at least in part, by proangiogenic factors synthesized by the tumor. However, HB tumor cells not only express Epo, VEGF and angiopoietin, but also the receptors of these cytokines (e.g., EpoR, Flk1/VEGFR2 and Tie2) [41, 118120], suggesting that they act as paracrine and autocrine growth factors to promote both angiogenesis and tumor growth. We have also shown that heterozygous VHL mice exhibited elevated angiogenic activity in response to bFGF stimulation due to increased FGF receptor accumulation in the endothelial cells [20].

Most interestingly, there is evidence that HB tumor cells are derived from developmentally arrested, hemangioblast-like stem cells [119122]. Hemangioblast is a structure that gives rise to the first endothelial and hematopoietic cells during embryogenesis (e.g., the extraembryonic yolk sack associated blood island) [123], and is thought to contain mesodermal stem cells that differentiate into both endothelial and hematopoietic cells, or, as recent findings suggest, sequentially into first endothelial, then hematopoietic stem cells, with a transient “hemogenic” endothelium [124, 125]. Similar to the hemangioblasts, tumor cells in hemangioblastoma express the early mesodermal marker Brachyury, as well as stem cell markers such as Flk1/VEGFR2, the transcription factor stem cell leukemia (scl) and CD133 [119, 121]. Furthermore, tumor cells isolated from hemangioblastoma give rise to both endothelial cells and hematopoietic cells when cultured in vitro [121] and foci of extramedullary hematopoiesis (EMH) are observed in advanced hemangioblastoma [120, 122]. Importantly, loss of heterozygosity is observed in the foci of EMH [120], confirming that they arise from VHL−/− cells. Since HB tumor cells can differentiate into endothelial cells in vitro, it is possible that de novo vasculogenesis contributes to the overgrowth of blood vessels observed in HB. Vortmeyer and colleagues detected fetal hemoglobin in HB-associated EMH foci, arguing that the VHL−/− cells found in HB contribute to primitive hematopoiesis [122]. The hematopoietic progenitor characteristics of these HB cells imply that they may originate from aberrantly mobilized HPSCs.

However, HB has also been reported to express neuronal markers such as neuron-specific enolase [126129], neural cell adhesion molecule [129131], and glial fibrillary acidic protein (GFAP), although the latter is controversial, with some studies suggesting that GFAP+ cells might correspond to entrapped astrocytes [96, 129, 132, 133]. Autopsy revealed widespread small ‘tumorlets’, which are thought to be hemangioblast precursors, in the roots of spinal nerves and the cerebellum of VHL patients [134136]. Detailed histological and immunhistochemical analysis of tumorlets and HB suggests that HB progresses from slowly proliferating mesenchymal cells to highly proliferative epithelioid cells, the latter displaying the clear cell morphology typical for VHL cancers [122, 134, 136]. Since the topology of hemangioblastoma coincides strikingly with the expression pattern of scl in the developing CNS, it was suggested that hemangioblastoma might arise from dormant stem cells of neurectodermal origin [119]. However, the expression of hemangioblastic markers and the mesodermal marker Brachyury is difficult to reconcile with a neurectodermal origin. On the other hand, no Brachyury expression was detected in tumorlets, which are thought to be dormant precursors of HB [134]. Due to its hybrid neuronal-mesodermal phenotype, the origin of HB tumors remains unclear. Nonetheless, it may be worth exploring whether primitive HPSCs or hemangioblast stem cells are implicated in HB. The CNS localization could be explained by homing defects of HPSCs involving endothelial cell adhesion molecules or chemoattractant cytokines specifically expressed by the CNS vasculature. In support of this hypothesis, homing defects were observed in VHL−/− HPSCs [29]. Furthermore, EMH targeting the spleen is observed in the R/R polycythemic mouse [33, 35], despite normal bone marrow function. Interestingly, leukemic EMH has been linked to the CXCR4-SDF-1 chemotactic system [137]. This is particularly relevant since CXCR4 is a HIF responsive gene that was shown to be up-regulated in VHL mutant cell lines [12], and is known to be expressed in ccRCC and HB [13]. Furthermore, CXCR4 was down-regulated in HIF-1−/− macrophages [72], indicating that HIF dosage regulates CXCR4 expression not only in cancer cells, but also in hematopoietic lineages. Since the CXCR4 chemotactic system is utilized in embryonic neuronal cell migration [138], it is possible that VHL mutant HPSCs may be aberrantly mobilized and ectopically localized to the future HB loci.

8. Perspectives

It has become increasingly clear that tumor progression is a systemic problem that involves, at the very least, the host immune and angiogenic responses. This is particularly true with the VHL disease. In the case of VHL patients, the host hematopoietic and immune systems are not simply responders to the growth of tumors but active contributors to the disease. This is suggested by the increasing body of evidence that links VHL function to the activity of HPSCs. Heterozygous VHL HPSCs and endothelial cells both show increased activities, suggesting that they may contribute to the hypervascular phenotype of the VHL tumors. Haploid-insufficient HPSCs may also promote tumor growth through increased inflammatory response or directly contributing multipotent cells to the tumor loci. In addition, VHL mutant tumor cells can secret a number of growth factors and cytokines that can also activate the inflammatory and angiogenic components of the primary tumors. We therefore argue that in designing new treatments for the VHL disease, a systemic approach including targeting the hematopoietic system and the inflammatory response should be considered.


The body of literature on VHL and HIF is very large, and many excellent papers were not cited due to space limitations. Also, since data on VHL are frequently published in papers whose main focus is HIF function, we cannot exclude that papers relevant to the topics of this review have been overlooked, and apologize if this should be the case. H.L.B. is a recipient of a NIH post-doctoral training grant (5T32HL007501-program director Dr. Adam Lerner). This work is also supported by a grant to T.H. from the National Institutes of Health, USA (R01CA109860).


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1. Herman JG, Latif F, Weng Y, Lerman MI, Zbar B, Liu S, Samid D, Duan DS, Gnarra JR, Linehan WM, et al. Silencing of the VHL tumor-suppressor gene by DNA methylation in renal carcinoma. Proc Natl Acad Sci U S A. 1994;91:9700–9704. [PubMed]
2. Kim WY, Kaelin WG. Role of VHL gene mutation in human cancer. J Clin Oncol. 2004;22:4991–5004. [PubMed]
3. Banks RE, Tirukonda P, Taylor C, Hornigold N, Astuti D, Cohen D, Maher ER, Stanley AJ, Harnden P, Joyce A, Knowles M, Selby PJ. Genetic and epigenetic analysis of von Hippel-Lindau (VHL) gene alterations and relationship with clinical variables in sporadic renal cancer. Cancer Res. 2006;66:2000–2011. [PubMed]
4. Pause A, Lee S, Worrell RA, Chen DY, Burgess WH, Linehan WM, Klausner RD. The von Hippel-Lindau tumor-suppressor gene product forms a stable complex with human CUL-2, a member of the Cdc53 family of proteins. Proc Natl Acad Sci U S A. 1997;94:2156–2161. [PubMed]
5. Lonergan KM, Iliopoulos O, Ohh M, Kamura T, Conaway RC, Conaway JW, Kaelin WG., Jr Regulation of hypoxia-inducible mRNAs by the von Hippel-Lindau tumor suppressor protein requires binding to complexes containing elongins B/C and Cul2. Mol Cell Biol. 1998;18:732–741. [PMC free article] [PubMed]
6. Kamura T, Koepp DM, Conrad MN, Skowyra D, Moreland RJ, Iliopoulos O, Lane WS, Kaelin WG, Jr, Elledge SJ, Conaway RC, Harper JW, Conaway JW. Rbx1, a component of the VHL tumor suppressor complex and SCF ubiquitin ligase. Science. 1999;284:657–661. [PubMed]
7. Lisztwan J, Imbert G, Wirbelauer C, Gstaiger M, Krek W. The von Hippel-Lindau tumor suppressor protein is a component of an E3 ubiquitin-protein ligase activity. Genes Dev. 1999;13:1822–1833. [PubMed]
8. Stebbins CE, Kaelin WG, Jr, Pavletich NP. Structure of the VHL-ElonginC-ElonginB complex: implications for VHL tumor suppressor function. Science. 1999;284:455–461. [PubMed]
9. Kaelin WG., Jr The von Hippel-Lindau protein, HIF hydroxylation, and oxygen sensing. Biochem Biophys Res Commun. 2005;338:627–638. [PubMed]
10. Berra E, Benizri E, Ginouves A, Volmat V, Roux D, Pouyssegur J. HIF prolyl-hydroxylase 2 is the key oxygen sensor setting low steady-state levels of HIF-1alpha in normoxia. EMBO J. 2003;22:4082–4090. [PubMed]
11. Kaelin WG. Von Hippel-Lindau disease. Annu Rev Pathol. 2007;2:145–173. [PubMed]
12. Staller P, Sulitkova J, Lisztwan J, Moch H, Oakeley EJ, Krek W. Chemokine receptor CXCR4 downregulated by von Hippel-Lindau tumour suppressor pVHL. Nature. 2003;425:307–311. [PubMed]
13. Zagzag D, Krishnamachary B, Yee H, Okuyama H, Chiriboga L, Ali MA, Melamed J, Semenza GL. Stromal cell-derived factor-1alpha and CXCR4 expression in hemangioblastoma and clear cell-renal cell carcinoma: von Hippel-Lindau loss-of-function induces expression of a ligand and its receptor. Cancer Res. 2005;65:6178–6188. [PubMed]
14. Hsu T. Complex cellular functions of the von Hippel-Lindau tumor suppressor gene: insights from model organisms. Oncogene. 2011 [PMC free article] [PubMed]
15. Frew IJ, Krek W. Multitasking by pVHL in tumour suppression. Curr Opin Cell Biol. 2007;19:685–690. [PubMed]
16. Bindra RS, Vasselli JR, Stearman R, Linehan WM, Klausner RD. VHL-mediated hypoxia regulation of cyclin D1 in renal carcinoma cells. Cancer Res. 2002;62:3014–3019. [PubMed]
17. Clark PE. The role of VHL in clear-cell renal cell carcinoma and its relation to targeted therapy. Kidney Int. 2009;76:939–945. [PMC free article] [PubMed]
18. Wilhelm S, Carter C, Lynch M, Lowinger T, Dumas J, Smith RA, Schwartz B, Simantov R, Kelley S. Discovery and development of sorafenib: a multikinase inhibitor for treating cancer. Nat Rev Drug Discov. 2006;5:835–844. [PubMed]
19. Dammai V, Adryan B, Lavenburg KR, Hsu T. Drosophila awd, the homolog of human nm23, regulates FGF receptor levels and functions synergistically with shi/dynamin during tracheal development. Genes Dev. 2003;17:2812–2824. [PubMed]
20. Champion KJ, Guinea M, Dammai V, Hsu T. Endothelial function of von Hippel-Lindau tumor suppressor gene: control of fibroblast growth factor receptor signaling. Cancer Res. 2008;68:4649–4657. [PMC free article] [PubMed]
21. Lutz MS, Burk RD. Primary cilium formation requires von hippel-lindau gene function in renal-derived cells. Cancer Res. 2006;66:6903–6907. [PubMed]
22. Schermer B, Ghenoiu C, Bartram M, Muller RU, Kotsis F, Hohne M, Kuhn W, Rapka M, Nitschke R, Zentgraf H, Fliegauf M, Omran H, Walz G, Benzing T. The von Hippel-Lindau tumor suppressor protein controls ciliogenesis by orienting microtubule growth. J Cell Biol. 2006;175:547–554. [PMC free article] [PubMed]
23. Esteban MA, Harten SK, Tran MG, Maxwell PH. Formation of primary cilia in the renal epithelium is regulated by the von Hippel-Lindau tumor suppressor protein. J Am Soc Nephrol. 2006;17:1801–1806. [PubMed]
24. Roe JS, Kim H, Lee SM, Kim ST, Cho EJ, Youn HD. p53 stabilization and transactivation by a von Hippel-Lindau protein. Mol Cell. 2006;22:395–405. [PubMed]
25. Walmsley SR, McGovern NN, Whyte MK, Chilvers ER. The HIF/VHL pathway: from oxygen sensing to innate immunity. Am J Respir Cell Mol Biol. 2008;38:251–255. [PubMed]
26. Imtiyaz HZ, Simon MC. Hypoxia-inducible factors as essential regulators of inflammation. Curr Top Microbiol Immunol. 2010;345:105–120. [PMC free article] [PubMed]
27. Nizet V, Johnson RS. Interdependence of hypoxic and innate immune responses. Nat Rev Immunol. 2009;9:609–617. [PMC free article] [PubMed]
28. Gale DP, Maxwell PH. The role of HIF in immunity. Int J Biochem Cell Biol. 2010;42:486–494. [PubMed]
29. Takubo K, Goda N, Yamada W, Iriuchishima H, Ikeda E, Kubota Y, Shima H, Johnson RS, Hirao A, Suematsu M, Suda T. Regulation of the HIF-1alpha level is essential for hematopoietic stem cells. Cell Stem Cell. 2010;7:391–402. [PubMed]
30. Walmsley SR, Cowburn AS, Clatworthy MR, Morrell NW, Roper EC, Singleton V, Maxwell P, Whyte MK, Chilvers ER. Neutrophils from patients with heterozygous germline mutations in the von Hippel Lindau protein (pVHL) display delayed apoptosis and enhanced bacterial phagocytosis. Blood. 2006;108:3176–3178. [PubMed]
31. Hsouna A, Nallamothu G, Kose N, Guinea M, Dammai V, Hsu T. Drosophila von Hippel-Lindau tumor suppressor gene function in epithelial tubule morphogenesis. Mol Cell Biol. 2010;30:3779–3794. [PMC free article] [PubMed]
32. Ang SO, Chen H, Gordeuk VR, Sergueeva AI, Polyakova LA, Miasnikova GY, Kralovics R, Stockton DW, Prchal JT. Endemic polycythemia in Russia: mutation in the VHL gene. Blood Cells Mol Dis. 2002;28:57–62. [PubMed]
33. Hickey MM, Lam JC, Bezman NA, Rathmell WK, Simon MC. Von Hippel-Lindau mutation in mice recapitulates Chuvash polycythemia via hypoxia-inducible factor-2 alpha signaling and splenic erythropoiesis. J Clin Invest. 2007;117:3879–3889. [PubMed]
34. van Rooijen E, Voest EE, Logister I, Korving J, Schwerte T, Schulte-Merker S, Giles RH, van Eeden FJ. Zebrafish mutants in the von Hippel-Lindau tumor suppressor display a hypoxic response and recapitulate key aspects of Chuvash polycythemia. Blood. 2009;113:6449–6460. [PubMed]
35. Russell RC, Sufan RI, Zhou B, Heir P, Bunda S, Sybingco SS, Greer SN, Roche O, Heathcote SA, Chow VW, Boba LM, Richmond TD, Hickey MM, Barber DL, Cheresh DA, Simon MC, Irwin MS, Kim WY, Ohh M. Loss of JAK2 regulation via a heterodimeric VHL-SOCS1 E3 ubiquitin ligase underlies Chuvash polycythemia. Nat Med. 2011;17:845–853. [PMC free article] [PubMed]
36. Jelkmann W. Regulation of erythropoietin production. J Physiol-London. 2011;589:1251–1258. [PubMed]
37. Maxwell PH, Osmond MK, Pugh CW, Heryet A, Nicholls LG, Tan CC, Doe BG, Ferguson DJ, Johnson MH, Ratcliffe PJ. Identification of the renal erythropoietin-producing cells using transgenic mice. Kidney Int. 1993;44:1149–1162. [PubMed]
38. Bachmann S, Le Hir M, Eckardt KU. Co-localization of erythropoietin mRNA and ecto-5'-nucleotidase immunoreactivity in peritubular cells of rat renal cortex indicates that fibroblasts produce erythropoietin. J Histochem Cytochem. 1993;41:335–341. [PubMed]
39. Maxwell PH, Ferguson DJ, Osmond MK, Pugh CW, Heryet A, Doe BG, Johnson MH, Ratcliffe PJ. Expression of a homologously recombined erythopoietin-SV40 T antigen fusion gene in mouse liver: evidence for erythropoietin production by Ito cells. Blood. 1994;84:1823–1830. [PubMed]
40. Papworth K, Bergh A, Grankvist K, Ljungberg B, Rasmuson T. Expression of erythropoietin and its receptor in human renal cell carcinoma. Tumour Biol. 2009;30:86–92. [PubMed]
41. Krieg M, Marti HH, Plate KH. Coexpression of erythropoietin and vascular endothelial growth factor in nervous system tumors associated with von Hippel-Lindau tumor suppressor gene loss of function. Blood. 1998;92:3388–3393. [PubMed]
42. Lee YS, Vortmeyer AO, Lubensky IA, Vogel TW, Ikejiri B, Ferlicot S, Benoit G, Giraud S, Oldfield EH, Linehan WM, Teh BT, Richard S, Zhuang Z. Coexpression of erythropoietin and erythropoietin receptor in von Hippel-Lindau disease-associated renal cysts and renal cell carcinoma. Clin Cancer Res. 2005;11:1059–1064. [PubMed]
43. Gong K, Zhang N, Zhang Z, Na YQ. Coexpression of erythopoietin and erythopoietin receptor in sporadic clear cell renal cell carcinoma. Cancer Biology & Therapy. 2006;5:582–585. [PubMed]
44. Shuai K, Liu B. Regulation of JAK-STAT signalling in the immune system. Nat Rev Immunol. 2003;3:900–911. [PubMed]
45. Gordeuk VR, Sergueeva AI, Miasnikova GY, Okhotin D, Voloshin Y, Choyke PL, Butman JA, Jedlickova K, Prchal JT, Polyakova LA. Congenital disorder of oxygen sensing: association of the homozygous Chuvash polycythemia VHL mutation with thrombosis and vascular abnormalities but not tumors. Blood. 2004;103:3924–3932. [PubMed]
46. Lappin TR, Maxwell AP, Johnston PG. EPO's alter ego: erythropoietin has multiple actions. Stem Cells. 2002;20:485–492. [PubMed]
47. Arcasoy MO. The non-haematopoietic biological effects of erythropoietin. Br J Haematol. 2008;141:14–31. [PubMed]
48. Purhonen S, Palm J, Rossi D, Kaskenpaa N, Rajantie I, Yla-Herttuala S, Alitalo K, Weissman IL, Salven P. Bone marrow-derived circulating endothelial precursors do not contribute to vascular endothelium and are not needed for tumor growth. Proc Natl Acad Sci U S A. 2008;105:6620–6625. [PubMed]
49. Hand CC, Brines M. Promises and pitfalls in erythopoietin-mediated tissue protection: are nonerythropoietic derivatives a way forward? J Investig Med. 2011;59:1073–1082. [PMC free article] [PubMed]
50. Leyland-Jones B, O'Shaughnessy JA. Erythropoietin as a critical component of breast cancer therapy: survival, synergistic, and cognitive applications. Semin Oncol. 2003;30:174–184. [PubMed]
51. Henke M, Laszig R, Rube C, Schafer U, Haase KD, Schilcher B, Mose S, Beer KT, Burger U, Dougherty C, Frommhold H. Erythropoietin to treat head and neck cancer patients with anaemia undergoing radiotherapy: randomised, double-blind, placebo-controlled trial. Lancet. 2003;362:1255–1260. [PubMed]
52. Arcasoy MO, Jiang X, Haroon ZA. Expression of erythropoietin receptor splice variants in human cancer. Biochem Biophys Res Commun. 2003;307:999–1007. [PubMed]
53. Yasuda Y, Fujita Y, Masuda S, Musha T, Ueda K, Tanaka H, Fujita H, Matsuo T, Nagao M, Sasaki R, Nakamura Y. Erythropoietin is involved in growth and angiogenesis in malignant tumours of female reproductive organs. Carcinogenesis. 2002;23:1797–1805. [PubMed]
54. Acs G, Zhang PJ, McGrath CM, Acs P, McBroom J, Mohyeldin A, Liu S, Lu H, Verma A. Hypoxia-inducible erythropoietin signaling in squamous dysplasia and squamous cell carcinoma of the uterine cervix and its potential role in cervical carcinogenesis and tumor progression. Am J Pathol. 2003;162:1789–1806. [PubMed]
55. Batra S, Perelman N, Luck LR, Shimada H, Malik P. Pediatric tumor cells express erythropoietin and a functional erythropoietin receptor that promotes angiogenesis and tumor cell survival. Lab Invest. 2003;83:1477–1487. [PubMed]
56. Yasuda Y, Fujita Y, Matsuo T, Koinuma S, Hara S, Tazaki A, Onozaki M, Hashimoto M, Musha T, Ogawa K, Fujita H, Nakamura Y, Shiozaki H, Utsumi H. Erythropoietin regulates tumour growth of human malignancies. Carcinogenesis. 2003;24:1021–1029. [PubMed]
57. Peyssonnaux C, Zinkernagel AS, Schuepbach RA, Rankin E, Vaulont S, Haase VH, Nizet V, Johnson RS. Regulation of iron homeostasis by the hypoxia-inducible transcription factors (HIFs) J Clin Invest. 2007;117:1926–1932. [PubMed]
58. Gong K, Zhang N, Zhang K, Na Y. The relationship of erythropoietin overexpression with von Hippel-Lindau tumour suppressor gene mutations between hypoxia-inducible factor-1alpha and-2alpha in sporadic clear cell renal carcinoma. Int J Mol Med. 2010;26:907–912. [PubMed]
59. Bento MC, Chang KT, Guan Y, Liu E, Caldas G, Gatti RA, Prchal JT. Congenital polycythemia with homozygous and heterozygous mutations of von Hippel-Lindau gene: five new Caucasian patients. Haematologica. 2005;90:128–129. [PubMed]
60. Cario H, Schwarz K, Jorch N, Kyank U, Petrides PE, Schneider DT, Uhle R, Debatin KM, Kohne E. Mutations in the von Hippel-Lindau (VHL) tumor suppressor gene and VHL-haplotype analysis in patients with presumable congenital erythrocytosis. Haematologica. 2005;90:19–24. [PubMed]
61. Pastore YD, Jelinek J, Ang S, Guan Y, Liu E, Jedlickova K, Krishnamurti L, Prchal JT. Mutations in the VHL gene in sporadic apparently congenital polycythemia. Blood. 2003;101:1591–1595. [PubMed]
62. Waldmann TA, Levin EH, Baldwin M. The association of polycythemia with a cerebellar hemangioblastoma. The production of an erythropoiesis stimulating factor by the tumor. Am J Med. 1961;31:318–324. [PubMed]
63. Watt SM, Athanassopoulos A, Harris AL, Tsaknakis G. Human endothelial stem/progenitor cells, angiogenic factors and vascular repair. J R Soc Interface. 2010;7(Suppl 6):S731–S751. [PMC free article] [PubMed]
64. Richardson MR, Yoder MC. Endothelial progenitor cells: quo vadis? J Mol Cell Cardiol. 2011;50:266–272. [PMC free article] [PubMed]
65. Qian BZ, Pollard JW. Macrophage diversity enhances tumor progression and metastasis. Cell. 2010;141:39–51. [PubMed]
66. Gao D, Nolan DJ, Mellick AS, Bambino K, McDonnell K, Mittal V. Endothelial progenitor cells control the angiogenic switch in mouse lung metastasis. Science. 2008;319:195–198. [PubMed]
67. Bhatt RS, Zurita AJ, O'Neill A, Norden-Zfoni A, Zhang L, Wu HK, Wen PY, George D, Sukhatme VP, Atkins MB, Heymach JV. Increased mobilisation of circulating endothelial progenitors in von Hippel-Lindau disease and renal cell carcinoma. Br J Cancer. 2011;105:112–117. [PMC free article] [PubMed]
68. Farace F, Gross-Goupil M, Tournay E, Taylor M, Vimond N, Jacques N, Billiot F, Mauguen A, Hill C, Escudier B. Levels of circulating CD45(dim)CD34(+)VEGFR2(+) progenitor cells correlate with outcome in metastatic renal cell carcinoma patients treated with tyrosine kinase inhibitors. Br J Cancer. 2011;104:1144–1150. [PMC free article] [PubMed]
69. Rad FH, Ulusakarya A, Gad S, Sibony M, Juin F, Richard S, Machover D, Uzan G. Novel somatic mutations of the VHL gene in an erythropoietin-producing renal carcinoma associated with secondary polycythemia and elevated circulating endothelial progenitor cells. Am J Hematol. 2008;83:155–158. [PubMed]
70. Heeschen C, Aicher A, Lehmann R, Fichtlscherer S, Vasa M, Urbich C, Mildner-Rihm C, Martin H, Zeiher AM, Dimmeler S. Erythropoietin is a potent physiologic stimulus for endothelial progenitor cell mobilization. Blood. 2003;102:1340–1346. [PubMed]
71. Kusmartsev S, Eruslanov E, Kubler H, Tseng T, Sakai Y, Su Z, Kaliberov S, Heiser A, Rosser C, Dahm P, Siemann D, Vieweg J. Oxidative stress regulates expression of VEGFR1 in myeloid cells: link to tumor-induced immune suppression in renal cell carcinoma. J Immunol. 2008;181:346–353. [PubMed]
72. Imtiyaz HZ, Williams EP, Hickey MM, Patel SA, Durham AC, Yuan LJ, Hammond R, Gimotty PA, Keith B, Simon MC. Hypoxia-inducible factor 2alpha regulates macrophage function in mouse models of acute and tumor inflammation. J Clin Invest. 2010;120:2699–2714. [PMC free article] [PubMed]
73. Kojima H, Kobayashi A, Sakurai D, Kanno Y, Hase H, Takahashi R, Totsuka Y, Semenza GL, Sitkovsky MV, Kobata T. Differentiation stage-specific requirement in hypoxia-inducible factor-1alpha-regulated glycolytic pathway during murine B cell development in bone marrow. J Immunol. 2010;184:154–163. [PMC free article] [PubMed]
74. Cramer T, Yamanishi Y, Clausen BE, Forster I, Pawlinski R, Mackman N, Haase VH, Jaenisch R, Corr M, Nizet V, Firestein GS, Gerber HP, Ferrara N, Johnson RS. HIF-1alpha is essential for myeloid cell-mediated inflammation. Cell. 2003;112:645–657. [PubMed]
75. Simsek T, Kocabas F, Zheng J, Deberardinis RJ, Mahmoud AI, Olson EN, Schneider JW, Zhang CC, Sadek HA. The distinct metabolic profile of hematopoietic stem cells reflects their location in a hypoxic niche. Cell Stem Cell. 2010;7:380–390. [PMC free article] [PubMed]
76. Kojima H, Gu H, Nomura S, Caldwell CC, Kobata T, Carmeliet P, Semenza GL, Sitkovsky MV. Abnormal B lymphocyte development and autoimmunity in hypoxia-inducible factor 1alpha -deficient chimeric mice. Proc Natl Acad Sci U S A. 2002;99:2170–2174. [PubMed]
77. Amara K, Trimeche M, Ziadi S, Laatiri A, Hachana M, Korbi S. Prognostic significance of aberrant promoter hypermethylation of CpG islands in patients with diffuse large B-cell lymphomas. Ann Oncol. 2008;19:1774–1786. [PubMed]
78. Kanduri M, Cahill N, Goransson H, Enstrom C, Ryan F, Isaksson A, Rosenquist R. Differential genome-wide array-based methylation profiles in prognostic subsets of chronic lymphocytic leukemia. Blood. 2010;115:296–305. [PubMed]
79. Ghosh AK, Shanafelt TD, Cimmino A, Taccioli C, Volinia S, Liu CG, Calin GA, Croce CM, Chan DA, Giaccia AJ, Secreto C, Wellik LE, Lee YK, Mukhopadhyay D, Kay NE. Aberrant regulation of pVHL levels by microRNA promotes the HIF/VEGF axis in CLL B cells. Blood. 2009;113:5568–5574. [PubMed]
80. Kalac M, Scotto L, Marchi E, Amengual J, Seshan VE, Bhagat G, Ulahannan N, Leshchenko VV, Temkin AM, Parekh S, Tycko B, O'Connor OA. HDAC inhibitors and decitabine are highly synergistic and associated with unique gene-expression and epigenetic profiles in models of DLBCL. Blood. 2011;118:5506–5516. [PubMed]
81. Neumann AK, Yang J, Biju MP, Joseph SK, Johnson RS, Haase VH, Freedman BD, Turka LA. Hypoxia inducible factor 1 alpha regulates T cell receptor signal transduction. Proc Natl Acad Sci U S A. 2005;102:17071–17076. [PubMed]
82. Biju MP, Neumann AK, Bensinger SJ, Johnson RS, Turka LA, Haase VH. Vhlh gene deletion induces Hif-1-mediated cell death in thymocytes. Mol Cell Biol. 2004;24:9038–9047. [PMC free article] [PubMed]
83. Lukashev D, Klebanov B, Kojima H, Grinberg A, Ohta A, Berenfeld L, Wenger RH, Sitkovsky M. Cutting edge: hypoxia-inducible factor 1alpha and its activation-inducible short isoform I.1 negatively regulate functions of CD4+ and CD8+ T lymphocytes. J Immunol. 2006;177:4962–4965. [PubMed]
84. Thiel M, Caldwell CC, Kreth S, Kuboki S, Chen P, Smith P, Ohta A, Lentsch AB, Lukashev D, Sitkovsky MV. Targeted deletion of HIF-1alpha gene in T cells prevents their inhibition in hypoxic inflamed tissues and improves septic mice survival. PLoS One. 2007;2:e853. [PMC free article] [PubMed]
85. Makino Y, Nakamura H, Ikeda E, Ohnuma K, Yamauchi K, Yabe Y, Poellinger L, Okada Y, Morimoto C, Tanaka H. Hypoxia-inducible factor regulates survival of antigen receptor-driven T cells. J Immunol. 2003;171:6534–6540. [PubMed]
86. Dang EV, Barbi J, Yang HY, Jinasena D, Yu H, Zheng Y, Bordman Z, Fu J, Kim Y, Yen HR, Luo W, Zeller K, Shimoda L, Topalian SL, Semenza GL, Dang CV, Pardoll DM, Pan F. Control of T(H)17/T(reg) balance by hypoxia-inducible factor 1. Cell. 2011;146:772–784. [PMC free article] [PubMed]
87. Ziegler SF, Buckner JH. FOXP3 and the regulation of Treg/Th17 differentiation. Microbes Infect. 2009;11:594–598. [PMC free article] [PubMed]
88. Peyssonnaux C, Datta V, Cramer T, Doedens A, Theodorakis EA, Gallo RL, Hurtado-Ziola N, Nizet V, Johnson RS. HIF-1alpha expression regulates the bactericidal capacity of phagocytes. J Clin Invest. 2005;115:1806–1815. [PMC free article] [PubMed]
89. Olson N, van der Vliet A. Interactions between nitric oxide and hypoxia-inducible factor signaling pathways in inflammatory disease. Nitric Oxide. 2011;25:125–137. [PMC free article] [PubMed]
90. Hickey MM, Richardson T, Wang T, Mosqueira M, Arguiri E, Yu H, Yu QC, Solomides CC, Morrisey EE, Khurana TS, Christofidou-Solomidou M, Simon MC. The von Hippel-Lindau Chuvash mutation promotes pulmonary hypertension and fibrosis in mice. J Clin Invest. 2010;120:827–839. [PMC free article] [PubMed]
91. Talks KL, Turley H, Gatter KC, Maxwell PH, Pugh CW, Ratcliffe PJ, Harris AL. The expression and distribution of the hypoxia-inducible factors HIF-1alpha and HIF-2alpha in normal human tissues, cancers, and tumor-associated macrophages. Am J Pathol. 2000;157:411–421. [PubMed]
92. Brukamp K, Jim B, Moeller MJ, Haase VH. Hypoxia and podocyte-specific Vhlh deletion confer risk of glomerular disease. Am J Physiol Renal Physiol. 2007;293:F1397–F1407. [PubMed]
93. Kimura K, Iwano M, Higgins DF, Yamaguchi Y, Nakatani K, Harada K, Kubo A, Akai Y, Rankin EB, Neilson EG, Haase VH, Saito Y. Stable expression of HIF-1alpha in tubular epithelial cells promotes interstitial fibrosis. Am J Physiol Renal Physiol. 2008;295:F1023–F1029. [PubMed]
94. Higgins DF, Kimura K, Bernhardt WM, Shrimanker N, Akai Y, Hohenstein B, Saito Y, Johnson RS, Kretzler M, Cohen CD, Eckardt KU, Iwano M, Haase VH. Hypoxia promotes fibrogenesis in vivo via HIF-1 stimulation of epithelial-to-mesenchymal transition. J Clin Invest. 2007;117:3810–3820. [PubMed]
95. Schietke RE, Hackenbeck T, Tran M, Gunther R, Klanke B, Warnecke CL, Knaup KX, Shukla D, Rosenberger C, Koesters R, Bachmann S, Betz P, Schley G, Schodel J, Willam C, Winkler T, Amann K, Eckardt KU, Maxwell P, Wiesener MS. Renal Tubular HIF-2alpha Expression Requires VHL Inactivation and Causes Fibrosis and Cysts. PLoS One. 2012;7:e31034. [PMC free article] [PubMed]
96. Galban S, Fan J, Martindale JL, Cheadle C, Hoffman B, Woods MP, Temeles G, Brieger J, Decker J, Gorospe M. von Hippel-Lindau protein-mediated repression of tumor necrosis factor alpha translation revealed through use of cDNA arrays. Mol Cell Biol. 2003;23:2316–2328. [PMC free article] [PubMed]
97. Ananth S, Knebelmann B, Gruning W, Dhanabal M, Walz G, Stillman IE, Sukhatme VP. Transforming growth factor beta1 is a target for the von Hippel-Lindau tumor suppressor and a critical growth factor for clear cell renal carcinoma. Cancer Res. 1999;59:2210–2216. [PubMed]
98. Yang H, Minamishima YA, Yan Q, Schlisio S, Ebert BL, Zhang X, Zhang L, Kim WY, Olumi AF, Kaelin WG., Jr pVHL acts as an adaptor to promote the inhibitory phosphorylation of the NF-kappaB agonist Card9 by CK2. Mol Cell. 2007;28:15–27. [PMC free article] [PubMed]
99. An J, Rettig MB. Mechanism of von Hippel-Lindau protein-mediated suppression of nuclear factor kappa B activity. Mol Cell Biol. 2005;25:7546–7556. [PMC free article] [PubMed]
100. Colotta F, Allavena P, Sica A, Garlanda C, Mantovani A. Cancer-related inflammation, the seventh hallmark of cancer: links to genetic instability. Carcinogenesis. 2009;30:1073–1081. [PubMed]
101. Grivennikov SI, Greten FR, Karin M. Immunity, inflammation, and cancer. Cell. 2010;140:883–899. [PMC free article] [PubMed]
102. Kraus S, Arber N. Inflammation and colorectal cancer. Curr Opin Pharmacol. 2009;9:405–410. [PubMed]
103. Hussain SP, Hofseth LJ, Harris CC. Radical causes of cancer. Nat Rev Cancer. 2003;3:276–285. [PubMed]
104. Koster JC, Permutt MA, Nichols CG. Diabetes and insulin secretion: the ATP-sensitive K+ channel (K ATP) connection. Diabetes. 2005;54:3065–3072. [PubMed]
105. Cantley J, Selman C, Shukla D, Abramov AY, Forstreuter F, Esteban MA, Claret M, Lingard SJ, Clements M, Harten SK, Asare-Anane H, Batterham RL, Herrera PL, Persaud SJ, Duchen MR, Maxwell PH, Withers DJ. Deletion of the von Hippel-Lindau gene in pancreatic beta cells impairs glucose homeostasis in mice. J Clin Invest. 2009;119:125–135. [PMC free article] [PubMed]
106. Zehetner J, Danzer C, Collins S, Eckhardt K, Gerber PA, Ballschmieter P, Galvanovskis J, Shimomura K, Ashcroft FM, Thorens B, Rorsman P, Krek W. PVHL is a regulator of glucose metabolism and insulin secretion in pancreatic beta cells. Genes Dev. 2008;22:3135–3146. [PubMed]
107. Choi D, Cai EP, Schroer SA, Wang L, Woo M. Vhl is required for normal pancreatic beta cell function and the maintenance of beta cell mass with age in mice. Lab Invest. 2011;91:527–538. [PubMed]
108. Puri S, Cano DA, Hebrok M. A role for von Hippel-Lindau protein in pancreatic beta-cell function. Diabetes. 2009;58:433–441. [PMC free article] [PubMed]
109. Shen HC, Adem A, Ylaya K, Wilson A, He M, Lorang D, Hewitt SM, Pechhold K, Harlan DM, Lubensky IA, Schmidt LS, Linehan WM, Libutti SK. Deciphering von Hippel-Lindau (VHL/Vhl)-associated pancreatic manifestations by inactivating Vhl in specific pancreatic cell populations. PLoS One. 2009;4:e4897. [PMC free article] [PubMed]
110. Cantley J, Grey ST, Maxwell PH, Withers DJ. The hypoxia response pathway and beta-cell function. Diabetes Obes Metab. 2010;12(Suppl 2):159–167. [PubMed]
111. Liang X, Shen D, Huang Y, Yin C, Bojanowski CM, Zhuang Z, Chan CC. Molecular pathology and CXCR4 expression in surgically excised retinal hemangioblastomas associated with von Hippel-Lindau disease. Ophthalmology. 2007;114:147–156. [PMC free article] [PubMed]
112. Butman JA, Linehan WM, Lonser RR. Neurologic manifestations of von Hippel-Lindau disease. JAMA. 2008;300:1334–1342. [PMC free article] [PubMed]
113. Lonser RR, Vortmeyer AO, Butman JA, Glasker S, Finn MA, Ammerman JM, Merrill MJ, Edwards NA, Zhuang Z, Oldfield EH. Edema is a precursor to central nervous system peritumoral cyst formation. Ann Neurol. 2005;58:392–399. [PubMed]
114. Glasker S, Vortmeyer AO, Lonser RR, Lubensky IA, Okamoto H, Xia JB, Li J, Milne E, Kowalak JA, Oldfield EH, Zhuang Z. Proteomic analysis of hemangioblastoma cyst fluid. Cancer Biol Ther. 2006;5:549–553. [PubMed]
115. Lee JY, Dong SM, Park WS, Yoo NJ, Kim CS, Jang JJ, Chi JG, Zbar B, Lubensky IA, Linehan WM, Vortmeyer AO, Zhuang Z. Loss of heterozygosity and somatic mutations of the VHL tumor suppressor gene in sporadic cerebellar hemangioblastomas. Cancer Res. 1998;58:504–508. [PubMed]
116. Vortmeyer AO, Gnarra JR, Emmert-Buck MR, Katz D, Linehan WM, Oldfield EH, Zhuang Z. von Hippel-Lindau gene deletion detected in the stromal cell component of a cerebellar hemangioblastoma associated with von Hippel-Lindau disease. Hum Pathol. 1997;28:540–543. [PubMed]
117. Vortmeyer AO, Huang SC, Pack SD, Koch CA, Lubensky IA, Oldfield EH, Zhuang Z. Somatic point mutation of the wild-type allele detected in tumors of patients with VHL germline deletion. Oncogene. 2002;21:1167–1170. [PubMed]
118. Wizigmann-Voos S, Breier G, Risau W, Plate KH. Up-regulation of vascular endothelial growth factor and its receptors in von Hippel-Lindau disease-associated and sporadic hemangioblastomas. Cancer Res. 1995;55:1358–1364. [PubMed]
119. Glasker S, Li J, Xia JB, Okamoto H, Zeng W, Lonser RR, Zhuang Z, Oldfield EH, Vortmeyer AO. Hemangioblastomas share protein expression with embryonal hemangioblast progenitor cell. Cancer Res. 2006;66:4167–4172. [PubMed]
120. Vortmeyer AO, Frank S, Jeong SY, Yuan K, Ikejiri B, Lee YS, Bhowmick D, Lonser RR, Smith R, Rodgers G, Oldfield EH, Zhuang Z. Developmental arrest of angioblastic lineage initiates tumorigenesis in von Hippel-Lindau disease. Cancer Res. 2003;63:7051–7055. [PubMed]
121. Park DM, Zhuang Z, Chen L, Szerlip N, Maric I, Li J, Sohn T, Kim SH, Lubensky IA, Vortmeyer AO, Rodgers GP, Oldfield EH, Lonser RR. von Hippel-Lindau disease-associated hemangioblastomas are derived from embryologic multipotent cells. PLoS Med. 2007;4:e60. [PubMed]
122. Shively SB, Beltaifa S, Gehrs B, Duong H, Smith J, Edwards NA, Lonser R, Raffeld M, Vortmeyer AO. Protracted haemangioblastic proliferation and differentiation in von Hippel-Lindau disease. J Pathol. 2008;216:514–520. [PubMed]
123. Palis J, Malik J, McGrath KE, Kingsley PD. Primitive erythropoiesis in the mammalian embryo. Int J Dev Biol. 2010;54:1011–1018. [PubMed]
124. Lancrin C, Sroczynska P, Stephenson C, Allen T, Kouskoff V, Lacaud G. The haemangioblast generates haematopoietic cells through a haemogenic endothelium stage. Nature. 2009;457:892–895. [PMC free article] [PubMed]
125. Eilken HM, Nishikawa S, Schroeder T. Continuous single-cell imaging of blood generation from haemogenic endothelium. Nature. 2009;457:896–900. [PubMed]
126. Feldenzer JA, McKeever PE. Selective localization of gamma-enolase in stromal cells of cerebellar hemangioblastomas. Acta Neuropathol. 1987;72:281–285. [PubMed]
127. Grant JW, Gallagher PJ, Hedinger C. Haemangioblastoma. An immunohistochemical study of ten cases. Acta Neuropathol. 1988;76:82–86. [PubMed]
128. Omulecka A, Lach B, Alwasiak J, Gregor A. Immunohistochemical and ultrastructural studies of stromal cells in hemangioblastoma. Folia Neuropathol. 1995;33:41–50. [PubMed]
129. Ishizawa K, Komori T, Hirose T. Stromal cells in hemangioblastoma: neuroectodermal differentiation and morphological similarities to ependymoma. Pathol Int. 2005;55:377–385. [PubMed]
130. Polydorides AD, Rosenblum MK, Edgar MA. Metastatic renal cell carcinoma to hemangioblastoma in von Hippel-Lindau disease. Arch Pathol Lab Med. 2007;131:641–645. [PubMed]
131. Bohling T, Maenpaa A, Timonen T, Vantunen L, Paetau A, Haltia M. Different expression of adhesion molecules on stromal cells and endothelial cells of capillary hemangioblastoma. Acta Neuropathol. 1996;92:461–466. [PubMed]
132. Kepes JJ, Rengachary SS, Lee SH. Astrocytes in hemangioblastomas of the central nervous system and their relationship to stromal cells. Acta Neuropathol. 1979;47:99–104. [PubMed]
133. Hasselblatt M, Jeibmann A, Gerss J, Behrens C, Rama B, Wassmann H, Paulus W. Cellular and reticular variants of haemangioblastoma revisited: a clinicopathologic study of 88 cases. Neuropathol Appl Neurobiol. 2005;31:618–622. [PubMed]
134. Shively SB, Falke EA, Li J, Tran MG, Thompson ER, Maxwell PH, Roessler E, Oldfield EH, Lonser RR, Vortmeyer AO. Developmentally arrested structures preceding cerebellar tumors in von Hippel-Lindau disease. Mod Pathol. 2011;24:1023–1030. [PMC free article] [PubMed]
135. Vortmeyer AO, Yuan Q, Lee YS, Zhuang Z, Oldfield EH. Developmental effects of von Hippel-Lindau gene deficiency. Ann Neurol. 2004;55:721–728. [PubMed]
136. Vortmeyer AO, Tran MG, Zeng W, Glasker S, Riley C, Tsokos M, Ikejiri B, Merrill MJ, Raffeld M, Zhuang Z, Lonser RR, Maxwell PH, Oldfield EH. Evolution of VHL tumourigenesis in nerve root tissue. J Pathol. 2006;210:374–382. [PubMed]
137. Kato I, Niwa A, Heike T, Fujino H, Saito MK, Umeda K, Hiramatsu H, Ito M, Morita M, Nishinaka Y, Adachi S, Ishikawa F, Nakahata T. Identification of hepatic niche harboring human acute lymphoblastic leukemic cells via the SDF-1/CXCR4 axis. PLoS One. 2011;6:e27042. [PMC free article] [PubMed]
138. Tiveron MC, Cremer H. CXCL12/CXCR4 signalling in neuronal cell migration. Curr Opin Neurobiol. 2008;18:237–244. [PubMed]