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Von Hippel-Lindau Gene Product Modulates TIS11B Expression in Renal Cell Carcinoma

Open AccessPublished:September 28, 2009DOI:https://doi.org/10.1074/jbc.M109.058065
      TIS11B belongs to a group of RNA-binding proteins (including TIS11/tristetraprolin and TIS11D) that share characteristic tandem CCCH-type zinc-finger domains and can be rapidly induced by multiple stimuli. TIS11B has been shown to regulate vascular endothelial growth factor (VEGF) mRNA stability in adrenocorticotropic hormone-stimulated primary adrenocortical cells. TIS11B has also been documented as a negative regulator of VEGF during development, but nothing has yet been reported in the context of human cancers. The Von Hippel-Lindau (VHL) tumor suppressor protein regulates VEGF gene expression at both the transcriptional and post-transcriptional levels in normoxia. However, whether it can do so in hypoxia is still unclear. Here, we report a unique regulatory function of VHL in VEGF expression in hypoxia that is mediated through modulation of TIS11B protein levels in renal cancer cells. In normoxia, we detected increased expression of the microRNA hsa-miR-29b in the VHL-overexpressing renal cancer cell line 786-O. We also show that this increased expression of hsa-miR-29b decreased TIS11B protein expression by post-transcriptional regulation in normoxia. In contrast, in hypoxia, increased TIS11B expression paralleled an increased TIS11B mRNA stability in VHL-overexpressing 786-O cells. This VHL-mediated TIS11B up-regulation in hypoxia may be important for TIS11B-regulated gene expression: we observed a down-regulation of VEGF mRNA in hypoxia in VHL-overexpressing cells compared with parental 786-O cells, and this effect was reversible by silencing TIS11B expression.

      Introduction

      Angiogenesis, the formation of new blood vessels from pre-existing vessels, is an essential process for establishing a closed circulatory system and for supplying oxygen and nutrients to tissues. Under normal circumstances, angiogenesis is a highly ordered and tightly regulated process of positive and negative regulatory pathways (
      • Folkman J.
      ,
      • Folkman J.
      • Klagsbrun M.
      ,
      • Folkman J.
      • Watson K.
      • Ingber D.
      • Hanahan D.
      ). Vascular endothelial growth factor (VEGF)
      The abbreviations used are: VEGF
      vascular endothelial growth factor
      VHL
      Von Hippel-Lindau
      RCC
      renal cell carcinoma
      ACTH
      adrenocorticotropic hormone
      3′-UTR
      3′-untranslated region
      miRNA
      microRNA
      siRNA
      small interfering RNA
      HIF
      hypoxia-inducible factor.
      is a critical signaling protein that plays a key role in developmental, physiological, and tumor angiogenesis (
      • Kim K.J.
      • Li B.
      • Winer J.
      • Armanini M.
      • Gillett N.
      • Phillips H.S.
      • Ferrara N.
      ,
      • Millauer B.
      • Shawver L.K.
      • Plate K.H.
      • Risau W.
      • Ullrich A.
      ,
      • Shweiki D.
      • Itin A.
      • Soffer D.
      • Keshet E.
      ). Of importance, up-regulation of VEGF expression by hypoxia appears to be a crucial step in the neovascularization of solid cancers (
      • Kim K.J.
      • Li B.
      • Winer J.
      • Armanini M.
      • Gillett N.
      • Phillips H.S.
      • Ferrara N.
      ,
      • Shweiki D.
      • Itin A.
      • Soffer D.
      • Keshet E.
      ,
      • Shweiki D.
      • Neeman M.
      • Itin A.
      • Keshet E.
      ). Tumor hypoxia appears to be strongly associated with tumor propagation, malignant progression, and resistance to therapy (
      • Höckel M.
      • Vaupel P.
      ).
      Germ line mutations of Von Hippel-Lindau (VHL), a tumor suppressor gene first described in 1993 (
      • Latif F.
      • Tory K.
      • Gnarra J.
      • Yao M.
      • Duh F.M.
      • Orcutt M.L.
      • Stackhouse T.
      • Kuzmin I.
      • Modi W.
      • Geil L.
      • Schmidt L.
      • Zhou F.
      • Li H.
      • Wei M.H.
      • Chen F.
      ), result in VHL-associated diseases such as renal cell carcinoma (RCC), hemangioblastoma, pheochromocytoma, and pancreatic cancer (
      • Maher E.R.
      • Kaelin Jr., W.G.
      ). VHL-associated tumors are highly vascularized (
      • Kaelin Jr., W.G.
      • Maher E.R.
      ) and support the existing model of VHL as a negative regulator of VEGF production (
      • Gnarra J.R.
      • Zhou S.
      • Merrill M.J.
      • Wagner J.R.
      • Krumm A.
      • Papavassiliou E.
      • Oldfield E.H.
      • Klausner R.D.
      • Linehan W.M.
      ,
      • Iliopoulos O.
      • Levy A.P.
      • Jiang C.
      • Kaelin Jr., W.G.
      • Goldberg M.A.
      ,
      • Levy A.P.
      • Levy N.S.
      • Iliopoulos O.
      • Jiang C.
      • Kaplin Jr., W.G.
      • Goldberg M.A.
      ). In RCC, VEGF overexpression has been shown to be regulated at both the transcriptional and post-transcriptional levels (
      • Mukhopadhyay D.
      • Datta K.
      ). In this regard, VHL has been reported to regulate VEGF transcription and mRNA stability in RCC, and these regulations are hypoxia-dependent (
      • Iliopoulos O.
      • Levy A.P.
      • Jiang C.
      • Kaelin Jr., W.G.
      • Goldberg M.A.
      ,
      • Levy A.P.
      • Levy N.S.
      • Iliopoulos O.
      • Jiang C.
      • Kaplin Jr., W.G.
      • Goldberg M.A.
      ,
      • Datta K.
      • Mondal S.
      • Sinha S.
      • Li J.
      • Wang E.
      • Knebelmann B.
      • Karumanchi S.A.
      • Mukhopadhyay D.
      ,
      • Maxwell P.H.
      • Wiesener M.S.
      • Chang G.W.
      • Clifford S.C.
      • Vaux E.C.
      • Cockman M.E.
      • Wykoff C.C.
      • Pugh C.W.
      • Maher E.R.
      • Ratcliffe P.J.
      ).
      The immediate-early protein tristetraprolin family consists of three known members in mammals (ZFP36 or tristetraprolin, ZFP36L1 or TIS11B (tetradecanoylphorbol acetate-inducible sequence 11B), and ZFP36L2 or TIS11D) and a fourth member found only in the mouse and rat (ZFP36L3). They share characteristic tandem CCCH-type zinc-finger domains, and although they are rapidly induced by multiple stimuli, their basal mRNA level varies (
      • Corps A.N.
      • Brown K.D.
      ,
      • Gomperts M.
      • Corps A.N.
      • Pascall J.C.
      • Brown K.D.
      ,
      • Varnum B.C.
      • Ma Q.F.
      • Chi T.H.
      • Fletcher B.
      • Herschman H.R.
      ). During these early responses, the localization, stability, and translation of specific mRNAs are affected (
      • Brown E.J.
      • Schreiber S.L.
      ,
      • Chen C.Y.
      • Shyu A.B.
      ), indicating the involvement of post-transcriptional regulatory mechanisms. However, their tissue-specific expression and regulation contribute to their specificity of action (
      • Ciais D.
      • Cherradi N.
      • Bailly S.
      • Grenier E.
      • Berra E.
      • Pouyssegur J.
      • Lamarre J.
      • Feige J.J.
      ). The ACTH-regulated zinc-finger protein TIS11B was reported to interact with the 3′-untranslated region (3′-UTR) of VEGF mRNA and to decrease its stability in primary adrenocortical cells (
      • Ciais D.
      • Cherradi N.
      • Bailly S.
      • Grenier E.
      • Berra E.
      • Pouyssegur J.
      • Lamarre J.
      • Feige J.J.
      ). The antagonistic function of TIS11B and HuR on VEGF mRNA stability in ACTH-stimulated adrenocortical cells has also been documented (
      • Cherradi N.
      • Lejczak C.
      • Desroches-Castan A.
      • Feige J.J.
      ). Chorioallantoic fusion defects and embryonic lethality result from the disruption of TIS11B in mice (
      • Stumpo D.J.
      • Byrd N.A.
      • Phillips R.S.
      • Ghosh S.
      • Maronpot R.R.
      • Castranio T.
      • Meyers E.N.
      • Mishina Y.
      • Blackshear P.J.
      ). The regulatory role of TIS11B has also expanded to include the control of normal vascularization, where TIS11B has been shown to regulate VEGF expression (
      • Bell S.E.
      • Sanchez M.J.
      • Spasic-Boskovic O.
      • Santalucia T.
      • Gambardella L.
      • Burton G.J.
      • Murphy J.J.
      • Norton J.D.
      • Clark A.R.
      • Turner M.
      ). However, its role in tumor angiogenesis is largely unknown.
      In this study, we investigated the role of VHL in the regulation of VEGF through TIS11B in RCC. We observed that VHL overexpression regulated TIS11B in the renal cancer cells (786-O). We also found that the microRNA (miRNA) hsa-miR-29b was overexpressed in 786-O cells expressing exogenous VHL, which could then target the TIS11B transcript to repress its expression under normoxia. However, under hypoxic stress, TIS11B mRNA became stabilized in the VHL-expressing 786-O cells and targeted the VEGF transcript for degradation.

      DISCUSSION

      RCC and other tumors that arise in patients with the VHL syndrome are characteristically well vascularized, a property that has been attributed to their consistent overexpression of the potent angiogenic factor VEGF (
      • Brown L.F.
      • Berse B.
      • Jackman R.W.
      • Tognazzi K.
      • Manseau E.J.
      • Dvorak H.F.
      • Senger D.R.
      ,
      • Leung D.W.
      • Cachianes G.
      • Kuang W.J.
      • Goeddel D.V.
      • Ferrara N.
      ,
      • Senger D.R.
      • Galli S.J.
      • Dvorak A.M.
      • Perruzzi C.A.
      • Harvey V.S.
      • Dvorak H.F.
      ,
      • Takahashi A.
      • Sasaki H.
      • Kim S.J.
      • Tobisu K.
      • Kakizoe T.
      • Tsukamoto T.
      • Kumamoto Y.
      • Sugimura T.
      • Terada M.
      ,
      • Wizigmann-Voos S.
      • Breier G.
      • Risau W.
      • Plate K.H.
      ). A number of factors have been reported to regulate VEGF in various tumors and in non-tumorigenic cells. One of the well studied regulators is hypoxic stress, and VHL has emerged as a key factor in cellular responses to hypoxia. It has been well established that VHL down-regulates VEGF gene expression at both the transcriptional and post-transcriptional levels in normoxia (
      • Gnarra J.R.
      • Zhou S.
      • Merrill M.J.
      • Wagner J.R.
      • Krumm A.
      • Papavassiliou E.
      • Oldfield E.H.
      • Klausner R.D.
      • Linehan W.M.
      ,
      • Levy A.P.
      • Levy N.S.
      • Iliopoulos O.
      • Jiang C.
      • Kaplin Jr., W.G.
      • Goldberg M.A.
      ,
      • Siemeister G.
      • Weindel K.
      • Mohrs K.
      • Barleon B.
      • Martiny-Baron G.
      • Marmé D.
      ,
      • Iliopoulos O.
      • Kibel A.
      • Gray S.
      • Kaelin Jr., W.G.
      ,
      • Mukhopadhyay D.
      • Knebelmann B.
      • Cohen H.T.
      • Ananth S.
      • Sukhatme V.P.
      ). However, the effect of VHL on VEGF regulation under hypoxic stress remains to be determined. In this study, we observed that the VEGF level in VHL-expressing 786-O cells remained significantly lower than that in the parental 786-O cells lacking endogenous VHL expression, even after prolonged hypoxia. Here, we have provided evidence as to how VHL regulates VEGF expression in hypoxia.
      In normoxia, 786-O cells expressing exogenous VHL express a low level of TIS11B. However, in these same cells under hypoxia, we detected an increased level of TIS11B expression in contrast to the level in the VHL-deficient renal cancer cell line 786-O. Our results suggest that VHL regulates VEGF synthesis through TIS11B primarily by two mechanisms depending on whether the environment is normoxic or hypoxic. VHL overexpression increases the level of the miRNA miR-29b in RCC. In normoxia, miR-29b in VHL-expressing cells targets the 3′-UTR of the RNA-binding protein TIS11B to down-regulate its translation without affecting mRNA stability. Although VHL-induced miR-29b expression remains unaltered by hypoxic stress, it seems to be functionally silent, as evidenced when the introduction of an anti-miR-29b oligonucleotide did not significantly affect the level of TIS11B in hypoxia. Therefore, it appears that VHL can regulate TIS11B through an alternative mechanism in a hypoxic environment. We detected a stabilization of the TIS11B transcript for an extended period in VHL-expressing cells compared with that in the parental VHL-null 786-O cells under hypoxic conditions. Thus, enhanced mRNA stabilization contributes significantly to maintain high levels of TIS11B in 786-O-VHL cells under hypoxia. Future studies are under way to delineate the mechanism of VHL-mediated regulation of the RNA-binding protein involved in TIS11B mRNA stabilization in hypoxia. Of importance, knockdown of TIS11B in hypoxia led to a significant increase in the VEGF mRNA level. These observations present a novel inhibitory role of VHL in VEGF regulation in hypoxia through increased TIS11B expression.
      Hypoxia is the major inducer of VEGF synthesis in both physiological and tumor angiogenesis. Although there are checks and balances during the physiological process of hypoxia-mediated VEGF-A synthesis, such tight control is absent in pathological angiogenesis. Hypoxia-inducible factor (HIF) and HuR are two molecules contributing mainly to the control of VEGF expression (
      • Carmeliet P.
      • Dor Y.
      • Herbert J.M.
      • Fukumura D.
      • Brusselmans K.
      • Dewerchin M.
      • Neeman M.
      • Bono F.
      • Abramovitch R.
      • Maxwell P.
      • Koch C.J.
      • Ratcliffe P.
      • Moons L.
      • Jain R.K.
      • Collen D.
      • Keshert E.
      ,
      • Levy N.S.
      • Chung S.
      • Furneaux H.
      • Levy A.P.
      ), and VHL has been shown to down-regulate HIF-2α and HuR to modulate the VEGF level in normoxia (
      • Datta K.
      • Mondal S.
      • Sinha S.
      • Li J.
      • Wang E.
      • Knebelmann B.
      • Karumanchi S.A.
      • Mukhopadhyay D.
      ,
      • Maxwell P.H.
      • Wiesener M.S.
      • Chang G.W.
      • Clifford S.C.
      • Vaux E.C.
      • Cockman M.E.
      • Wykoff C.C.
      • Pugh C.W.
      • Maher E.R.
      • Ratcliffe P.J.
      ,
      • Ivan M.
      • Kondo K.
      • Yang H.
      • Kim W.
      • Valiando J.
      • Ohh M.
      • Salic A.
      • Asara J.M.
      • Lane W.S.
      • Kaelin Jr., W.G.
      ,
      • Jaakkola P.
      • Mole D.R.
      • Tian Y.M.
      • Wilson M.I.
      • Gielbert J.
      • Gaskell S.J.
      • von Kriegsheim A.
      • Hebestreit H.F.
      • Mukherji M.
      • Schofield C.J.
      • Maxwell P.H.
      • Pugh C.W.
      • Ratcliffe P.J.
      ). VHL-deficient RCC and other tumor cells have been reported to express high levels of TIS11B (
      • Carrick D.M.
      • Blackshear P.J.
      ). One possible reason for this high level of TIS11B expression in normoxia is to override the active positive regulators (e.g. HIF-2α and HuR) of VEGF synthesis. However, in VHL-expressing cells, even a low level of TIS11B is important for maintaining VEGF expression under a threshold value in normoxia because knockdown of TIS11B in these cells also shows an up-regulation of VEGF.
      In 2006, Bell et al. (
      • Bell S.E.
      • Sanchez M.J.
      • Spasic-Boskovic O.
      • Santalucia T.
      • Gambardella L.
      • Burton G.J.
      • Murphy J.J.
      • Norton J.D.
      • Clark A.R.
      • Turner M.
      ) showed that TIS11B mutant embryos exhibited extraembryonic and intraembryonic vascular defects, cardiac abnormalities, and an elevated level of VEGF. Additionally, TIS11B has been shown to be an important regulator of myogenic differentiation (
      • Busse M.
      • Schwarzburger M.
      • Berger F.
      • Hacker C.
      • Munz B.
      ). The lack of TIS11B expression during mid-gestation has also been linked to anomalous placentation and fetal death due to the abnormal stabilization of one or more mRNAs (
      • Stumpo D.J.
      • Byrd N.A.
      • Phillips R.S.
      • Ghosh S.
      • Maronpot R.R.
      • Castranio T.
      • Meyers E.N.
      • Mishina Y.
      • Blackshear P.J.
      ). Therefore, in VHL-expressing cells, we believe that a balanced TIS11B-regulated VEGF level in both normoxia and hypoxia is important for its physiological function. As shown here with the loss of VHL, TIS11B-regulated VEGF synthesis is also impaired and this, in turn, favors unrestricted expression of VEGF and its subsequent pathological effects.
      Our findings on regulation of VEGF by the VHL/TIS11B axis in RCC are summarized in Fig. 8. In normoxia, RCC 786-O cells express an increased level of TIS11B protein to override the active positive regulators (e.g. HIF-2α and HuR) of VEGF-A and synthesize a moderately high level of VEGF-A. In hypoxia, however, a decrease in TIS11B expression relieves its inhibitory effects on VEGF-A, allowing a further increase in VEGF-A synthesis under the control of HIF and HuR in 786-O cells. Interestingly, VHL overexpression in 786-O cells keeps the TIS11B level low by inhibiting TIS11B translation through miR-29b in normoxia. VEGF-A expression also remains low in VHL-overexpressing 786-O cells in normoxia because of VHL-mediated inhibition of HuR and HIF activity. Although miR-29b expression remains unaltered in VHL-overexpressing 786-O cells under hypoxia, an increased stability of TIS11B mRNA has been observed, and stabilized TIS11B maintains VEGF-A expression at ∼30% lower levels compared with the VEGF-A levels found in 786-O null cells under hypoxic stress. Here, our data uncovered a novel inhibitory pathway regulating VEGF synthesis through interplay between the VHL/miR-29b/TIS11B axis and HIF/HuR positive regulatory axis under hypoxia.
      Figure thumbnail gr8
      FIGURE 8Model for VHL-modulated TIS11B expression in regulation of VEGF-A in RCC. A, in normoxia, RCC 786-O cells express an increased level of TIS11B protein, overriding the active positive regulators (e.g. HIF-2α and HuR) of VEGF-A, and a moderately high level of VEGF-A is detected. B, in hypoxia in 786-O cells, TIS11B expression decreases, which allows for increased VEGF-A synthesis. C, in normoxia, VHL overexpression down-regulates the positive regulators of VEGF synthesis and increases the level of the miRNA miR-29b in RCC. An elevated level of miR-29b in VHL-expressing cells targets the 3′-UTR of the RNA-binding protein TIS11B and down-regulates its translation. VEGF-A expression then remains low in VHL-overexpressing 786-O cells in normoxia. D, in hypoxia, VHL-induced miR-29b expression remains unaltered. However, mRNA stabilization contributes significantly to maintaining high levels of TIS11B in 786-O-VHL cells. This stabilized TIS11B keeps VEGF-A expression low compared with the VEGF-A levels found in 786-O null cells under hypoxic stress.

      Acknowledgments

      We thank Julie Lau for discussions.

      REFERENCES

        • Folkman J.
        Sci. Am. 1996; 275: 150-154
        • Folkman J.
        • Klagsbrun M.
        Science. 1987; 235: 442-447
        • Folkman J.
        • Watson K.
        • Ingber D.
        • Hanahan D.
        Nature. 1989; 339: 58-61
        • Kim K.J.
        • Li B.
        • Winer J.
        • Armanini M.
        • Gillett N.
        • Phillips H.S.
        • Ferrara N.
        Nature. 1993; 362: 841-844
        • Millauer B.
        • Shawver L.K.
        • Plate K.H.
        • Risau W.
        • Ullrich A.
        Nature. 1994; 367: 576-579
        • Shweiki D.
        • Itin A.
        • Soffer D.
        • Keshet E.
        Nature. 1992; 359: 843-845
        • Shweiki D.
        • Neeman M.
        • Itin A.
        • Keshet E.
        Proc. Natl. Acad. Sci. U.S.A. 1995; 92: 768-772
        • Höckel M.
        • Vaupel P.
        J. Natl. Cancer Inst. 2001; 93: 266-276
        • Latif F.
        • Tory K.
        • Gnarra J.
        • Yao M.
        • Duh F.M.
        • Orcutt M.L.
        • Stackhouse T.
        • Kuzmin I.
        • Modi W.
        • Geil L.
        • Schmidt L.
        • Zhou F.
        • Li H.
        • Wei M.H.
        • Chen F.
        Science. 1993; 260: 1317-1320
        • Maher E.R.
        • Kaelin Jr., W.G.
        Medicine. 1997; 76: 381-391
        • Kaelin Jr., W.G.
        • Maher E.R.
        Trends Genet. 1998; 14: 423-426
        • Gnarra J.R.
        • Zhou S.
        • Merrill M.J.
        • Wagner J.R.
        • Krumm A.
        • Papavassiliou E.
        • Oldfield E.H.
        • Klausner R.D.
        • Linehan W.M.
        Proc. Natl. Acad. Sci. U.S.A. 1996; 93: 10589-10594
        • Iliopoulos O.
        • Levy A.P.
        • Jiang C.
        • Kaelin Jr., W.G.
        • Goldberg M.A.
        Proc. Natl. Acad. Sci. U.S.A. 1996; 93: 10595-10599
        • Levy A.P.
        • Levy N.S.
        • Iliopoulos O.
        • Jiang C.
        • Kaplin Jr., W.G.
        • Goldberg M.A.
        Kidney Int. 1997; 51: 575-578
        • Mukhopadhyay D.
        • Datta K.
        Semin. Cancer Biol. 2004; 14: 123-130
        • Datta K.
        • Mondal S.
        • Sinha S.
        • Li J.
        • Wang E.
        • Knebelmann B.
        • Karumanchi S.A.
        • Mukhopadhyay D.
        Oncogene. 2005; 24: 7850-7858
        • Maxwell P.H.
        • Wiesener M.S.
        • Chang G.W.
        • Clifford S.C.
        • Vaux E.C.
        • Cockman M.E.
        • Wykoff C.C.
        • Pugh C.W.
        • Maher E.R.
        • Ratcliffe P.J.
        Nature. 1999; 399: 271-275
        • Corps A.N.
        • Brown K.D.
        FEBS Lett. 1995; 368: 160-164
        • Gomperts M.
        • Corps A.N.
        • Pascall J.C.
        • Brown K.D.
        FEBS Lett. 1992; 306: 1-4
        • Varnum B.C.
        • Ma Q.F.
        • Chi T.H.
        • Fletcher B.
        • Herschman H.R.
        Mol. Cell. Biol. 1991; 11: 1754-1758
        • Brown E.J.
        • Schreiber S.L.
        Cell. 1996; 86: 517-520
        • Chen C.Y.
        • Shyu A.B.
        Trends Biochem. Sci. 1995; 20: 465-470
        • Ciais D.
        • Cherradi N.
        • Bailly S.
        • Grenier E.
        • Berra E.
        • Pouyssegur J.
        • Lamarre J.
        • Feige J.J.
        Oncogene. 2004; 23: 8673-8680
        • Cherradi N.
        • Lejczak C.
        • Desroches-Castan A.
        • Feige J.J.
        Mol. Endocrinol. 2006; 20: 916-930
        • Stumpo D.J.
        • Byrd N.A.
        • Phillips R.S.
        • Ghosh S.
        • Maronpot R.R.
        • Castranio T.
        • Meyers E.N.
        • Mishina Y.
        • Blackshear P.J.
        Mol. Cell. Biol. 2004; 24: 6445-6455
        • Bell S.E.
        • Sanchez M.J.
        • Spasic-Boskovic O.
        • Santalucia T.
        • Gambardella L.
        • Burton G.J.
        • Murphy J.J.
        • Norton J.D.
        • Clark A.R.
        • Turner M.
        Dev. Dyn. 2006; 235: 3144-3155
        • Pichiorri F.
        • Suh S.S.
        • Ladetto M.
        • Kuehl M.
        • Palumbo T.
        • Drandi D.
        • Taccioli C.
        • Zanesi N.
        • Alder H.
        • Hagan J.P.
        • Munker R.
        • Volinia S.
        • Boccadoro M.
        • Garzon R.
        • Palumbo A.
        • Aqeilan R.I.
        • Croce C.M.
        Proc. Natl. Acad. Sci. U.S.A. 2008; 105: 12885-12890
        • Griffiths-Jones S.
        • Grocock R.J.
        • van Dongen S.
        • Bateman A.
        • Enright A.J.
        Nucleic Acids Res. 2006; 34: D140-D144
        • Ivan M.
        • Kondo K.
        • Yang H.
        • Kim W.
        • Valiando J.
        • Ohh M.
        • Salic A.
        • Asara J.M.
        • Lane W.S.
        • Kaelin Jr., W.G.
        Science. 2001; 292: 464-468
        • Jaakkola P.
        • Mole D.R.
        • Tian Y.M.
        • Wilson M.I.
        • Gielbert J.
        • Gaskell S.J.
        • von Kriegsheim A.
        • Hebestreit H.F.
        • Mukherji M.
        • Schofield C.J.
        • Maxwell P.H.
        • Pugh C.W.
        • Ratcliffe P.J.
        Science. 2001; 292: 468-472
        • Valencia-Sanchez M.A.
        • Liu J.
        • Hannon G.J.
        • Parker R.
        Genes Dev. 2006; 20: 515-524
        • Brown L.F.
        • Berse B.
        • Jackman R.W.
        • Tognazzi K.
        • Manseau E.J.
        • Dvorak H.F.
        • Senger D.R.
        Am. J. Pathol. 1993; 143: 1255-1262
        • Leung D.W.
        • Cachianes G.
        • Kuang W.J.
        • Goeddel D.V.
        • Ferrara N.
        Science. 1989; 246: 1306-1309
        • Senger D.R.
        • Galli S.J.
        • Dvorak A.M.
        • Perruzzi C.A.
        • Harvey V.S.
        • Dvorak H.F.
        Science. 1983; 219: 983-985
        • Takahashi A.
        • Sasaki H.
        • Kim S.J.
        • Tobisu K.
        • Kakizoe T.
        • Tsukamoto T.
        • Kumamoto Y.
        • Sugimura T.
        • Terada M.
        Cancer Res. 1994; 54: 4233-4237
        • Wizigmann-Voos S.
        • Breier G.
        • Risau W.
        • Plate K.H.
        Cancer Res. 1995; 55: 1358-1364
        • Siemeister G.
        • Weindel K.
        • Mohrs K.
        • Barleon B.
        • Martiny-Baron G.
        • Marmé D.
        Cancer Res. 1996; 56: 2299-2301
        • Iliopoulos O.
        • Kibel A.
        • Gray S.
        • Kaelin Jr., W.G.
        Nat. Med. 1995; 1: 822-826
        • Mukhopadhyay D.
        • Knebelmann B.
        • Cohen H.T.
        • Ananth S.
        • Sukhatme V.P.
        Mol. Cell. Biol. 1997; 17: 5629-5639
        • Carmeliet P.
        • Dor Y.
        • Herbert J.M.
        • Fukumura D.
        • Brusselmans K.
        • Dewerchin M.
        • Neeman M.
        • Bono F.
        • Abramovitch R.
        • Maxwell P.
        • Koch C.J.
        • Ratcliffe P.
        • Moons L.
        • Jain R.K.
        • Collen D.
        • Keshert E.
        Nature. 1998; 394: 485-490
        • Levy N.S.
        • Chung S.
        • Furneaux H.
        • Levy A.P.
        J. Biol. Chem. 1998; 273: 6417-6423
        • Carrick D.M.
        • Blackshear P.J.
        Arch. Biochem. Biophys. 2007; 462: 278-285
        • Busse M.
        • Schwarzburger M.
        • Berger F.
        • Hacker C.
        • Munz B.
        Eur. J. Cell Biol. 2008; 87: 31-38