Cancer Research AACR Legacy Protein Translation and Cancer
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Cancer Research Clinical Cancer Research
Cancer Epidemiology Biomarkers & Prevention Molecular Cancer Therapeutics
Molecular Cancer Research Cancer Prevention Research
Cancer Prevention Journals Portal Cancer Reviews Online
Annual Meeting Education Book Meeting Abstracts Online
Cancer Research 67, 4537, May 15, 2007. doi: 10.1158/0008-5472.CAN-07-0391
© 2007 American Association for Cancer Research
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kuehn, E. W.
Right arrow Articles by Benzing, T.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Kuehn, E. W.
Right arrow Articles by Benzing, T.
Related Collections
Right arrow Cellular Pathobiology
Right arrow Cellular Pathobiology: Cancer Genes and Genomics
Right arrow Cellular Pathobiology: Proliferation, Senescence, and Death

Review

von Hippel-Lindau: A Tumor Suppressor Links Microtubules to Ciliogenesis and Cancer Development

E. Wolfgang Kuehn1, Gerd Walz1 and Thomas Benzing2

1 Renal Division, University Hospital Freiburg, Freiburg, Germany and 2 Department of Medicine IV, University of Cologne, Cologne, Germany

Requests for reprints: Thomas Benzing, Department of Medicine IV, University of Cologne, Kerpener Strasse 62, D-50924 Köln, Germany. Phone: 49-221-478-4480; Fax: 49-221-478-5959; E-mail: thomas.benzing{at}uk-koeln.de.


   Abstract
Top
 Abstract
Background: von Hippel-Lindau...
 pVHL Is Required for...
 A New Light on...
 References
 
Loss of von Hippel-Lindau (VHL) tumor suppressor gene function occurs in familial and most sporadic renal cell carcinoma. The tumor suppressor role of the protein pVHL is based on its ability to target transcription factors of the hypoxia-inducible factor family for degradation, but other functions of pVHL are less clearly defined. New findings show that pVHL is necessary for cilia formation. pVHL interacts with PAR proteins, a complex that specifies the membrane domains of polarized epithelial cells, and directs the orientation of growing microtubules. Loss of pVHL results in aberrant orientation of newly formed microtubules and prevents ciliogenesis. These results add to a growing body of evidence linking cilia and the cell cycle and suggest that the tumor suppressor role of pVHL may involve previously unrecognized pathways. [Cancer Res 2007;67(10):4537–40]


   Background: von Hippel-Lindau and Renal Cysts
Top
 Abstract
 Background: von Hippel-Lindau...
pVHL Is Required for...
 A New Light on...
 References
 
The von Hippel-Lindau (VHL) syndrome is an inherited disease characterized by the development of tumors in the adrenal glands (pheochromocytomas), blood vessels (hemangioblastomas), and the kidney (clear cell carcinomas; ref. 1). It is caused by an inherited mutation in one of two alleles of the tumor suppressor gene VHL. Somatic mutations in the unaffected second gene copy result in malignant transformation of individual cells and tumor formation (2). The VHL protein (pVHL) is part of an E3 ubiquitin ligase complex that targets proteins for proteasomal degradation. This function is best established for the degradation of members of the hypoxia-inducible factor protein family (2). Hypoxia-inducible factor transcription factors are tightly controlled under normoxic conditions. Low oxygen tension prevents the posttranslational modifications of hypoxia-inducible factors, necessary for their ubiquitylation by the pVHL containing E3 ubiquitin ligase complex, and results in activation of several target genes to guide the adaptation to hypoxia (3). Hypoxia-inducible factors are up-regulated in renal cancers in VHL disease and in a large proportion of sporadic clear cell carcinomas as well. Despite substantial evidence from animal models, that the lost control of hypoxia-inducible factors by pVHL is a key step in tumor formation, the contribution of other pVHL functions to tumorigenesis is less clear (4).

In the kidneys of patients with VHL disease, renal tumors are preceded by the development of premalignant cysts that may resemble classic autosomal-dominant polycystic kidney disease (5). Polycystic kidney disease occurs in all age groups and encompasses a spectrum of clinically and genetically heterogeneous disorders (6). Cystic kidney diseases in general are caused by mutations in proteins that are localized to primary cilia or centrosomes (7, 8). Cilia are hair-like structures containing longitudinal strands of microtubules that originate from the surface of polarized renal epithelial cells (9). In polarized epithelial cells, the centrosome is located beneath the apical cell surface and is anchored to the plasma membrane, where it forms the basal body, from which the cilium originates (Fig. 1 ). Primary cilia in the kidney are nonmotile organelles, which have been shown to act as flow sensors (10). Bending of cilia by flow, leading to intracellular calcium transients, has been linked to activation of signaling cascades, such as the noncanonical Wnt signaling pathway involved in regulating epithelial cell polarity (11, 12). Most importantly, ciliary signaling also seems to inhibit canonical Wnt signaling, preventing the stabilization of ß-catenin and the downstream events that have been implicated in tumorigenesis of various cancer types.


Figure 1
View larger version (43K):
[in this window]
[in a new window]
[Download PPT slide]
  		Figure 1. Hypothetical model of pVHL function in ciliogenesis and cell cycle control. In a wild-type cell, pVHL binds to microtubules (MT) and the Par3-Par6-aPKC complex to direct microtubule orientation. This enables the centrosome to migrate to the apical membrane, where it is attached to transition fibers. The membrane-anchored centrosome forms the basal body for the outgrowing cilium, which keeps the cell in G0 as long as a cilium is present. In VHL-deficient cells, microtubule growth is disordered, preventing migration of the centrosome to the plasma membrane. No cilium can be formed and the cells cannot arrest in G0.

 

   pVHL Is Required for Cilia Formation and Regulates Microtubule Orientation
Top
 Abstract
 Background: von Hippel-Lindau...
 pVHL Is Required for...
A New Light on...
 References
 
The fact that pVHL disease causes kidney cysts and the link between kidney cysts and dysfunction of cilia and centrosomes strongly suggest that pVHL plays a role in the function of these organelles. Indeed, recent evidence from three independent groups indicates that pVHL is localized to primary cilia and required for ciliary assembly (13–15). Renal cancer cells lacking pVHL are deficient of cilia, whereas ectopic expression of pVHL in these cells reestablished cilia growth. Conversely, reduction of pVHL by RNA interference–mediated knockdown in renal epithelial cells resulted in the loss of primary cilia, strongly suggesting that pVHL function is required for ciliogenesis (15). The fact that loss of pVHL results in the absence of cilia may explain why VHL disease is associated with kidney cysts and provides further proof for the ciliary hypothesis of cyst formation. However, the question remains how pVHL functions in the process of ciliogenesis. Hergovich et al. (16) found that pVHL binds to and stabilizes microtubules. This finding is potentially pertinent to cilia because the ciliary axoneme contains stable microtubules, as indicated by a high content of acetylated tubulin. A recent report, examining microtubular polymerization by live cell imaging of fluorescence-tagged end binding protein-1, suggests that pVHL controls the orientation of microtubule formation (15). End binding protein-1 is present in a large cytoplasmic pool and caps the plus ends of growing microtubules. When tagged with GFP, end binding protein-1 marks the plus end of growing microtubules and can be used to dynamically monitor microtubule growth (Fig. 1). Schermer et al. showed that microtubule growth is oriented toward the periphery of the cells in cells expressing pVHL. In pVHL-deficient cells, however, the orientation of microtubule growth is disturbed, resulting in disordered directions of microtubule assembly (Fig. 1).

Microtubule stability and polarization play an important role in the differentiation of cells. Rho family GTPases, such as Cdc42, have been shown to modulate microtubule polarity by regulating cortical microtubule capture through Par6 and atypical protein kinase C (aPKC; ref. 17). The Par3-Par6-aPKC complex is also involved in formation and localization of the tight junction, thereby defining the apical and basolateral domains of epithelial cells (18). Additionally Par3, Par6, and aPKC have been shown to localize to primary cilia, and RNA interference–mediated knockdown of the Par3 binding partner 14-3-3{eta}, a Par5 homologue, resulted in the loss of cilia (19). Thus, the fact that pVHL associates with the Par3-Par6-aPKC complex suggests that pVHL may be involved in polarization of cells (15).

However, the question why microtubular disorientation in pVHL-deficient cells prevents cilia formation remains unanswered. Ciliogenesis is dependent on intraflagellar transport proteins (IFT) proteins (9), but thus far, no link between pVHL and IFT proteins has been found. One prerequisite for cilia formation is the anchoring of the centrosome to the plasma membrane (20). Several studies have analyzed factors involved in the docking of the centrosome (reviewed in ref. 20), but no data exist on the effectors of centrosome positioning during ciliogenesis. In nonpolarized cells, the centrosome functions as the microtubule-organizing center. Interestingly, centrosome positioning in migrating cells is regulated by the Par3-Par6-aPKC complex (17, 21). Thus, it is tempting to speculate that pVHL in concert with Par3, Par6, and aPKC is important in guiding the centrosome and anchoring it to the plasma membrane. The potential inability to target the centrosome correctly to the plasma membrane could explain the defective ciliogenesis in pVHL-deficient cells. In this respect, it is interesting to note that the adenomatous polyposis coli protein, which is another microtubule-interacting tumor suppressor, has been shown to regulate the orientation of the centrosome in migrating astrocytes, probably by influencing microtubule capture at the cortical membrane (21, 22). An alternative hypothesis of how the lack of microtubule orientation in VHL-deficient cells affects ciliogenesis might involve a more general disturbance in the establishment of apicobasal polarity, perhaps through impaired formation of the tight junction or other polarity determinants.


   A New Light on Cilia and the Cell Cycle
Top
 Abstract
 Background: von Hippel-Lindau...
 pVHL Is Required for...
 A New Light on...
References
 
Can these new findings be linked to the role of pVHL as a tumor suppressor? It has been known for a long time that cilia are in tune with the cell cycle. Differentiated cells in G0 carry cilia, which are resorbed before mitosis (23). The centrosomes duplicate and serve as anchoring points for the mitotic spindle. The cilia reappear after cell division is completed. In the kidney, loss of cilia causes cysts, which are characterized by an increase in proliferation of cyst lining epithelial cells. (The incidence of renal cell carcinoma in most types of cystic kidney disease is not increased, however). Examples of ciliary proteins, which have been linked to the cell cycle, include inversin, a protein mutated in a form of cystic kidney disease presenting in children. Inversin interacts with anaphase promoting complex protein 2 and displays a cell cycle–dependent expression pattern, suggesting that it may have a role in regulating the cell cycle (24). Two very interesting recent articles show a role for IFT proteins in cell cycle regulation. IFT88, the protein mutated in the polycystic orpk mouse, is localized at the centrioles, similar to other IFT proteins (25). Overexpression of IFT88 results in cell cycle arrest, whereas small interfering RNA–induced knockdown of IFT88 causes increased cell proliferation. Conversely, the reduction of IFT27, a Rab-like GTPase in the biflagellate algae Chlamydomonas reinhardtii, has been reported recently to inhibit cell growth, probably through a defect in cytokinesis (26). Further clues to the role of cilia in cell cycle regulation come from two members of the NIMA-related expressed kinase family in Chlamydomonas, Fa2p and Cnk2p, which both localize to flagella [see also the excellent review by Quarmby and Parker (27)]. NIMA, a kinase first identified in Aspergillus, functionally interacts with cyclin-dependent kinase 1, regulating the entry into the mitotic phase (28). Fa2p similarly plays a role at the G2-M transition but additionally plays a role in an alternative mechanism of ciliary loss called deflagellation, where the flagellum is severed close to the plasma membrane (27). This observation supports a potential link between deciliation and cell cycle regulation and suggests that failure to shed the cilium could negatively affect mitosis. Cnk2p, the second ciliary Nek, is involved in the regulation of cell size and flagellar length, both of which are associated with the cell cycle (27). Interestingly, mutation of two mammalian orthologues of Neks, Nek1 and Nek8, causes cystic kidney disease when mutated in mice, and Nek1 interacts with ciliary proteins, such as kinesin 2. Nek8 is localized in cilia (29) and is up-regulated in human breast cancer, supporting the link between ciliary proteins and cancer (30). Furthermore, components of several signaling pathways, including the Sonic hedgehog and platelet-derived growth factor receptor-{alpha} pathways, have been found in cilia (31). These signaling pathways are dysregulated in cancer. Thus, it is tempting to speculate that the cilium restricts the activation of these pathways to prevent uncontrolled proliferation and tumorigenesis.

In summary, recent findings suggest a role for the tumor suppressor protein pVHL in controlling ciliogenesis and microtubule dynamics. These observations have provided new insights into the function of this multifunctional molecule and stimulated the intriguing hypothesis that microtubule dynamics, positioning of centrosomes, and ciliogenesis play important roles in cell cycle control. Future work on the molecular details of pVHL function in this complex relationship will certainly not only provide us with valuable insight into tumorigenesis but also suggest new therapeutic targets for the treatment of cancer.


   Acknowledgments
 
We thank the members of the Benzing and Walz laboratories for helpful discussions. We apologize to all researchers whose outstanding contributions to the field could not be mentioned here due to space limitations.

Received 1/30/07. Revised 3/20/07. Accepted 3/30/07.


   References
Top
 Abstract
 Background: von Hippel-Lindau...
 pVHL Is Required for...
 A New Light on...
 References
 

  1. Lonser RR, Glenn GM, Walther M, et al. von Hippel-Lindau disease. Lancet 2003;361:2059–67.[CrossRef][Medline]
  2. Kaelin WG, Jr. The von Hippel-Lindau tumor suppressor gene and kidney cancer. Clin Cancer Res 2004;10:6290–5S.[CrossRef]
  3. Gordan JD, Simon MC. Hypoxia-inducible factors: central regulators of the tumor phenotype. Curr Opin Genet Dev 2007;17:71–7.[CrossRef][Medline]
  4. Kaelin WG. The von Hippel-Lindau tumor suppressor protein: roles in cancer and oxygen sensing. Cold Spring Harb Symp Quant Biol 2005;70:159–66.[CrossRef][Medline]
  5. Lubensky IA, Gnarra JR, Bertheau P, Walther MM, Linehan WM, Zhuang Z. Allelic deletions of the VHL gene detected in multiple microscopic clear cell renal lesions in von Hippel-Lindau disease patients. Am J Pathol 1996;149:2089–94.[Abstract]
  6. Guay-Woodford LM. Renal cystic diseases: diverse phenotypes converge on the cilium/centrosome complex. Pediatr Nephrol 2006;21:1369–76.[CrossRef][Medline]
  7. Pazour GJ. Intraflagellar transport and cilia-dependent renal disease: the ciliary hypothesis of polycystic kidney disease. J Am Soc Nephrol 2004;15:2528–36.[Abstract/Free Full Text]
  8. Davenport JR, Yoder BK. An incredible decade for the primary cilium: a look at a once-forgotten organelle. Am J Physiol Renal Physiol 2005;289:F1159–69.[Abstract/Free Full Text]
  9. Rosenbaum JL, Witman GB. Intraflagellar transport. Nat Rev Mol Cell Biol 2002;3:813–25.[CrossRef][Medline]
  10. Praetorius HA, Spring KR. Bending the MDCK cell primary cilium increases intracellular calcium. J Membr Biol 2001;184:71–9.[CrossRef][Medline]
  11. Simons M, Gloy J, Ganner A, et al. Inversin, the gene product mutated in nephronophthisis type II, functions as a molecular switch between Wnt signaling pathways. Nat Genet 2005;37:537–43.[CrossRef][Medline]
  12. Ross AJ, May-Simera H, Eichers ER, et al. Disruption of Bardet-Biedl syndrome ciliary proteins perturbs planar cell polarity in vertebrates. Nat Genet 2005;37:1135–40.[CrossRef][Medline]
  13. 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;17:1801–6.[Abstract/Free Full Text]
  14. Lutz MS, Burk RD. Primary cilium formation requires von Hippel-Lindau gene function in renal-derived cells. Cancer Res 2006;66:6903–7.[Abstract/Free Full Text]
  15. Schermer B, Ghenoiu C, Bartram M, et al. The von Hippel-Lindau tumor suppressor protein controls ciliogenesis by orienting microtubule growth. J Cell Biol 2006;175:547–54.[Abstract/Free Full Text]
  16. Hergovich A, Lisztwan J, Barry R, Ballschmieter P, Krek W. Regulation of microtubule stability by the von Hippel-Lindau tumour suppressor protein pVHL. Nat Cell Biol 2003;5:64–70.[CrossRef][Medline]
  17. Gundersen GG, Gomes ER, Wen Y. Cortical control of microtubule stability and polarization. Curr Opin Cell Biol 2004;16:106–12.[CrossRef][Medline]
  18. Hurd TW, Fan S, Liu CJ, Kweon HK, Hakansson K, Margolis B. Phosphorylation-dependent binding of 14-3-3 to the polarity protein Par3 regulates cell polarity in mammalian epithelia. Curr Biol 2003;13:2082–90.[CrossRef][Medline]
  19. Fan S, Hurd TW, Liu CJ, et al. Polarity proteins control ciliogenesis via kinesin motor interactions. Curr Biol 2004;14:1451–61.[CrossRef][Medline]
  20. Dawe HR, Farr H, Gull K. Centriole/basal body morphogenesis and migration during ciliogenesis in animal cells. J Cell Sci 2007;120:7–15.[Abstract/Free Full Text]
  21. Etienne-Manneville S, Hall A. Cdc42 regulates GSK-3ß and adenomatous polyposis coli to control cell polarity. Nature 2003;421:753–6.[CrossRef][Medline]
  22. Wen Y, Eng CH, Schmoranzer J, et al. EB1 and APC bind to mDia to stabilize microtubules downstream of Rho and promote cell migration. Nat Cell Biol 2004;6:820–30.[CrossRef][Medline]
  23. Wheatley DN, Wang AM, Strugnell GE. Expression of primary cilia in mammalian cells. Cell Biol Int 1996;20:73–81.[CrossRef][Medline]
  24. Morgan D, Eley L, Sayer J, et al. Expression analyses and interaction with the anaphase promoting complex protein Apc2 suggest a role for inversin in primary cilia and involvement in the cell cycle. Hum Mol Genet 2002;11:3345–50.[Abstract/Free Full Text]
  25. Robert A, Margall-Ducos G, Guidotti JE, et al. The intraflagellar transport component IFT88/polaris is a centrosomal protein regulating G1-S transition in non-ciliated cells. J Cell Sci 2007;120:628–37.[Abstract/Free Full Text]
  26. Qin H, Wang Z, Diener D, Rosenbaum J. Intraflagellar transport protein 27 is a small G protein involved in cell-cycle control. Curr Biol 2007;17:193–202.[CrossRef][Medline]
  27. Quarmby LM, Parker JD. Cilia and the cell cycle? J Cell Biol 2005;169:707–10.[Abstract/Free Full Text]
  28. O'Connell MJ, Krien MJ, Hunter T. Never say never. The NIMA-related protein kinases in mitotic control. Trends Cell Biol 2003;13:221–8.[CrossRef][Medline]
  29. Mahjoub MR, Trapp ML, Quarmby LM. NIMA-related kinases defective in murine models of polycystic kidney diseases localize to primary cilia and centrosomes. J Am Soc Nephrol 2005;16:3485–9.[Abstract/Free Full Text]
  30. Bowers AJ, Boylan JF. Nek8, a NIMA family kinase member, is overexpressed in primary human breast tumors. Gene 2004;328:135–42.[CrossRef][Medline]
  31. Michaud EJ, Yoder BK. The primary cilium in cell signaling and cancer. Cancer Res 2006;66:6463–7.[Abstract/Free Full Text]



This article has been cited by other articles:


Home page
 Cancer Res.Home page
Y. Yang, J. Bai, R. Shen, S. A.N. Brown, E. Komissarova, Y. Huang, N. Jiang, G. F. Alberts, M. Costa, L. Lu, et al.
Polo-like Kinase 3 Functions as a Tumor Suppressor and Is a Negative Regulator of Hypoxia-Inducible Factor-1{alpha} under Hypoxic Conditions
Cancer Res., June 1, 2008; 68(11): 4077 - 4085.
[Abstract] [Full Text] [PDF]

Home page
 Cancer Res.Home page
G. M. O'Neill, S. Seo, I. G. Serebriiskii, S. R. Lessin, and E. A. Golemis
A New Central Scaffold for Metastasis: Parsing HEF1/Cas-L/NEDD9
Cancer Res., October 1, 2007; 67(19): 8975 - 8979.
[Abstract] [Full Text] [PDF]

Home page
 CRO ContentHome page
G. C. Prendergast
Biological research in cancer: Convergent versus divergent problems
Cancer Reviews Online Content, June 1, 2007; 2007(3): 5 - 6.
[Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kuehn, E. W.
Right arrow Articles by Benzing, T.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Kuehn, E. W.
Right arrow Articles by Benzing, T.
Related Collections
Right arrow Cellular Pathobiology
Right arrow Cellular Pathobiology: Cancer Genes and Genomics
Right arrow Cellular Pathobiology: Proliferation, Senescence, and Death

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Cancer Research Clinical Cancer Research
Cancer Epidemiology Biomarkers & Prevention Molecular Cancer Therapeutics
Molecular Cancer Research Cancer Prevention Research
Cancer Prevention Journals Portal Cancer Reviews Online
Annual Meeting Education Book Meeting Abstracts Online