Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Inactivation of the p53 pathway in retinoblastoma


Most human tumours have genetic mutations in their Rb and p53 pathways, but retinoblastoma is thought to be an exception. Studies suggest that retinoblastomas, which initiate with mutations in the gene retinoblastoma 1 (RB1), bypass the p53 pathway because they arise from intrinsically death-resistant cells during retinal development. In contrast to this prevailing theory, here we show that the tumour surveillance pathway mediated by Arf, MDM2, MDMX and p53 is activated after loss of RB1 during retinogenesis. RB1-deficient retinoblasts undergo p53-mediated apoptosis and exit the cell cycle. Subsequently, amplification of the MDMX gene and increased expression of MDMX protein are strongly selected for during tumour progression as a mechanism to suppress the p53 response in RB1-deficient retinal cells. Our data provide evidence that the p53 pathway is inactivated in retinoblastoma and that this cancer does not originate from intrinsically death-resistant cells as previously thought. In addition, they support the idea that MDMX is a specific chemotherapeutic target for treating retinoblastoma.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type



Prices may be subject to local taxes which are calculated during checkout

Figure 1: MDMX amplification correlates with decreased activity of the p53 pathway.
Figure 2: Retinoblastoma cells show a p53 response to DNA damage.
Figure 3: MDMX promotes retinal tumorigenesis in mice.
Figure 4: MDMX rescues cell death in RB1-deficient human retinoblasts.
Figure 5: Nutlin-3 inhibits MDMX activity in retinoblastoma.


  1. Hahn, W. C. & Weinberg, R. A. Modelling the molecular circuitry of cancer. Nature Rev. Cancer 2, 331–341 (2002)

    Article  CAS  Google Scholar 

  2. Vogelstein, B. & Kinzler, K. W. Cancer genes and the pathways they control. Nature Med. 10, 789–799 (2004)

    Article  CAS  PubMed  Google Scholar 

  3. Sherr, C. J. & McCormick, F. The RB and p53 pathways in cancer. Cancer Cell 2, 103–112 (2002)

    Article  CAS  PubMed  Google Scholar 

  4. Chau, B. N. & Wang, J. Y. Coordinated regulation of life and death by RB. Nature Rev. Cancer 3, 130–138 (2003)

    Article  CAS  Google Scholar 

  5. Vogelstein, B., Lane, D. & Levine, A. J. Surfing the p53 network. Nature 408, 307–310 (2000)

    Article  ADS  CAS  PubMed  Google Scholar 

  6. Oren, M. Decision making by p53: life, death and cancer. Cell Death Differ. 10, 431–442 (2003)

    Article  CAS  PubMed  Google Scholar 

  7. Prives, C. & Hall, P. A. The p53 pathway. J. Pathol. 187, 112–126 (1999)

    Article  CAS  PubMed  Google Scholar 

  8. Honda, R., Tanaka, H. & Yasuda, H. Oncoprotein MDM2 is a ubiquitin ligase E3 for tumor suppressor p53. FEBS Lett. 420, 25–27 (1997)

    Article  CAS  PubMed  Google Scholar 

  9. Kubbutat, M. H., Jones, S. N. & Vousden, K. H. Regulation of p53 stability by Mdm2. Nature 387, 299–303 (1997)

    Article  ADS  CAS  PubMed  Google Scholar 

  10. Momand, J., Jung, D., Wilczynski, S. & Niland, J. The MDM2 gene amplification database. Nucleic Acids Res. 26, 3453–3459 (1998)

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Yang, Y. et al. Small molecule inhibitors of HDM2 ubiquitin ligase activity stabilize and activate p53 in cells. Cancer Cell 7, 547–559 (2005)

    Article  CAS  PubMed  Google Scholar 

  12. Vassilev, L. T. et al. In vivo activation of the p53 pathway by small-molecule antagonists of MDM2. Science 303, 844–848 (2004)

    Article  ADS  CAS  PubMed  Google Scholar 

  13. Kato, M. V. et al. Loss of heterozygosity on chromosome 17 and mutation of the p53 gene in retinoblastoma. Cancer Lett. 106, 75–82 (1996)

    Article  CAS  PubMed  Google Scholar 

  14. Nork, T. M., Poulsen, G. L., Millecchia, L. L., Jantz, R. G. & Nickells, R. W. p53 regulates apoptosis in human retinoblastoma. Arch. Ophthalmol. 115, 213–219 (1997)

    Article  CAS  PubMed  Google Scholar 

  15. Chen, D. et al. Cell-specific effects of RB or RB/p107 loss on retinal development implicate an intrinsically death-resistant cell-of-origin in retinoblastoma. Cancer Cell 5, 539–551 (2004)

    Article  CAS  PubMed  Google Scholar 

  16. Dyer, M. A. & Bremner, R. The search for the retinoblastoma cell of origin. Nature Rev. Cancer 5, 91–101 (2005)

    Article  CAS  Google Scholar 

  17. Aslanian, A., Iaquinta, P. J., Verona, R. & Lees, J. A. Repression of the Arf tumor suppressor by E2F3 is required for normal cell cycle kinetics. Genes Dev. 18, 1413–1422 (2004)

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. Lowe, S. W. & Sherr, C. J. Tumor suppression by Ink4a-Arf: progress and puzzles. Curr. Opin. Genet. Dev. 13, 77–83 (2003)

    Article  CAS  PubMed  Google Scholar 

  19. Zhang, J., Schweers, B. & Dyer, M. A. The first knockout mouse model of retinoblastoma. Cell Cycle 3, 952–959 (2004)

    CAS  PubMed  Google Scholar 

  20. Donovan, S., Schweers, B., Martins, R., Johnson, D. & Dyer, M. A. Compensation by tumor suppressor genes during retinal development in mice and humans. BMC Biol. 4, 14 (2006)

    Article  PubMed  PubMed Central  Google Scholar 

  21. Shvarts, A. et al. MDMX: a novel p53-binding protein with some functional properties of MDM2. EMBO J. 15, 5349–5357 (1996)

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  22. Danovi, D. et al. Amplification of Mdmx (or Mdm4) directly contributes to tumor formation by inhibiting p53 tumor suppressor activity. Mol. Cell. Biol. 24, 5835–5843 (2004)

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. McKenzie, P. P., McPake, C. R., Ashford, A. A., Vanin, E. F. & Harris, L. C. MDM2 does not influence p53-mediated sensitivity to DNA-damaging drugs. Mol. Cancer Ther. 1, 1097–1104 (2002)

    CAS  PubMed  Google Scholar 

  24. Canman, C. E. et al. Activation of the ATM kinase by ionizing radiation and phosphorylation of p53. Science 281, 1677–1679 (1998)

    Article  ADS  CAS  PubMed  Google Scholar 

  25. Kastan, M. B., Lim, D. S., Kim, S. T. & Yang, D. ATM—a key determinant of multiple cellular responses to irradiation. Acta Oncol. 40, 686–688 (2001)

    Article  CAS  PubMed  Google Scholar 

  26. Kastan, M. B., Onyekwere, O., Sidransky, D., Vogelstein, B. & Craig, R. W. Participation of p53 protein in the cellular response to DNA damage. Cancer Res. 51, 6304–6311 (1991)

    CAS  PubMed  Google Scholar 

  27. Brummelkamp, T. R., Bernards, R. & Agami, R. A system for stable expression of short interfering RNAs in mammalian cells. Science 296, 550–553 (2002)

    Article  ADS  CAS  PubMed  Google Scholar 

  28. Baker, S. J., Markowitz, S., Fearon, E. R., Willson, J. K. & Vogelstein, B. Suppression of human colorectal carcinoma cell growth by wild-type p53. Science 249, 912–915 (1990)

    Article  ADS  CAS  PubMed  Google Scholar 

  29. Robanus-Maandag, E. et al. p107 is a suppressor of retinoblastoma development in pRb-deficient mice. Genes Dev. 12, 1599–1609 (1998)

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  30. MacPherson, D. et al. Cell type-specific effects of Rb deletion in the murine retina. Genes Dev. 18, 1681–1694 (2004)

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Dyer, M. A. & Harbour, J. W. in Clinical Ocular Oncology Ch. 66 (eds Singh, A. D., Damato, B., Murphree, A. L. & Perry, J. D.) (Elsevier, London, in the press).

  32. Dyer, M. A., Rodriguez-Galindo, C. & Wilson, M. W. Use of preclinical models to improve treatment of retinoblastoma. PLoS Med. 2, e332 (2005)

    Article  PubMed  PubMed Central  Google Scholar 

  33. Marquardt, T. et al. Pax6 is required for the multipotent state of retinal progenitor cells. Cell 105, 43–55 (2001)

    Article  CAS  PubMed  Google Scholar 

  34. Lu, F. et al. Proteomimetic libraries: design, synthesis, and evaluation of p53–MDM2 interaction inhibitors. J. Comb. Chem. 8, 315–325 (2006)

    Article  CAS  PubMed  Google Scholar 

  35. Dang, J. et al. The RING domain of Mdm2 can inhibit cell proliferation. Cancer Res. 62, 1222–1230 (2002)

    CAS  PubMed  Google Scholar 

  36. Laurie, N. A. et al. Topotecan combination chemotherapy in two new rodent models of retinoblastoma. Clin. Cancer Res. 11, 7569–7578 (2005)

    Article  CAS  PubMed  Google Scholar 

Download references


We thank L. Harris, G. Zambetti and M. Baron for discussions; S. Pounds for statistical analysis; M. Roussel for MDMX and MDM2 retroviruses; B. Schulman and D. Bashford for assistance with MDMX–nutlin-3 modelling; A. McArthur for editorial assistance; J. Gray for assistance with real-time RT–PCR and genomic DNA preparations; and F. Carlotti and M. Rabeling for advice on lentiviral experiments and production of lentivirus stocks. This work was supported by grants (to M.A.D.) from the National Eye Institute, Cancer Center Support from the National Cancer Institute, the American Cancer Society, Research to Prevent Blindness, the Pearle Vision Foundation, the International Retinal Research Foundation and the American Lebanese Syrian Associated Charities (ALSAC). M.A.D. is a Pew Scholar. This work was also supported by funding from the Association for International Cancer Research (A.G.J.) and EC FP6 (A.G.J. and J.-C.M.), the Dutch Cancer Society (Y.R.), the Belgian Foundation against Cancer (J.-C.M.) and Télévie (S.F.). This publication was supported in part by a grant from the National Cancer Institute.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Michael A. Dyer.

Ethics declarations

Competing interests

Reprints and permissions information is available at The authors declare no competing financial interests.

Supplementary information

Supplementary Notes

This file contains Supplementary Tables 1–8, Supplementary Figures 1–10 and detailed Supplementary Methods. The Supplementary Tables present data from dissociated cell scoring, FISH analysis and clone size analysis of MDM2Lox/Lox MEFs. The Supplementary Figures provide additional data on modulation of the p53 pathway by MDM2 and MDMX in normal and transformed cells. The figures also provide additional data on the mechanism of topotecan and nutlin-3 mediated killing of retinoblastoma cells and cell-based assays demonstrating that nutlin-3 can kill Mdm2-deficient MEFs by binding to MdmX. The Supplementary Methods provide details about antibodies, cDNAs, siRNAs, microscopy, retinoblastoma tissue analysis, statistical analysis, protein purification and nutlin-3 binding studies and MEF experiments. (PDF 5104 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Laurie, N., Donovan, S., Shih, CS. et al. Inactivation of the p53 pathway in retinoblastoma. Nature 444, 61–66 (2006).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing