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Division and apoptosis of E2f-deficient retinal progenitors

Abstract

The activating E2f transcription factors (E2f1, E2f2 and E2f3) induce transcription and are widely viewed as essential positive cell cycle regulators. Indeed, they drive cells out of quiescence, and the ‘cancer cell cycle’ in Rb1 null cells is E2f-dependent1,2. Absence of activating E2fs in flies or mammalian fibroblasts causes cell cycle arrest3,4, but this block is alleviated by removing repressive E2f or the tumour suppressor p53, respectively5,6,7. Thus, whether activating E2fs are indispensable for normal division is an area of debate1. Activating E2fs are also well known pro-apoptotic factors, providing a defence against oncogenesis8, yet E2f1 can limit irradiation-induced apoptosis9,10. In flies this occurs through repression of hid (also called Wrinkled; Smac/Diablo in mammals). However, in mammals the mechanism is unclear because Smac/Diablo is induced, not repressed, by E2f111, and in keratinocytes survival is promoted indirectly through induction of DNA repair targets12. Thus, a direct pro-survival function for E2f1–3 and/or its relevance beyond irradiation has not been established. To address E2f1–3 function in normal cells in vivo we focused on the mouse retina, which is a relatively simple central nervous system component that can be manipulated genetically without compromising viability and has provided considerable insight into development and cancer2,13. Here we show that unlike fibroblasts, E2f1–3 null retinal progenitor cells or activated Müller glia can divide. We attribute this effect to functional interchangeability with Mycn. However, loss of activating E2fs caused downregulation of the p53 deacetylase Sirt1, p53 hyperacetylation and elevated apoptosis, establishing a novel E2f–Sirt1–p53 survival axis in vivo. Thus, activating E2fs are not universally required for normal mammalian cell division, but have an unexpected pro-survival role in development.

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Figure 1: Mycn allows division without activating E2fs.
Figure 2: Mycn blocks Cdk inhibitor induction in E2f1–3 null progenitors.
Figure 3: A pro-survival role for activating E2fs.
Figure 4: E2fs promote survival through Sirt1-mediated p53 deacetylation.

References

  1. Rowland, B. D. & Bernards, R. Re-evaluating cell-cycle regulation by E2Fs. Cell 127, 871–874 (2006)

    CAS  Article  Google Scholar 

  2. Pacal, M. & Bremner, R. Insights from animal models on the origins and progression of retinoblastoma. Curr. Mol. Med. 6, 759–781 (2006)

    CAS  PubMed  Google Scholar 

  3. van den Heuvel, S. & Dyson, N. J. Conserved functions of the pRB and E2F families. Nature Rev. Mol. Cell Biol. 9, 713–724 (2008)

    CAS  Article  Google Scholar 

  4. Wu, L. et al. The E2F1–3 transcription factors are essential for cellular proliferation. Nature 414, 457–462 (2001)

    ADS  CAS  Article  Google Scholar 

  5. Timmers, C. et al. E2f1, E2f2, and E2f3 control E2F target expression and cellular proliferation via a p53-dependent negative feedback loop. Mol. Cell. Biol. 27, 65–78 (2007)

    CAS  Article  Google Scholar 

  6. Sharma, N. et al. Control of the p53-p21CIP1 axis by E2f1, E2f2, and E2f3 is essential for G1/S progression and cellular transformation. J. Biol. Chem. 281, 36124–36131 (2006)

    CAS  Article  Google Scholar 

  7. Frolov, M. V. et al. Functional antagonism between E2F family members. Genes Dev. 15, 2146–2160 (2001)

    CAS  Article  Google Scholar 

  8. Iaquinta, P. J. & Lees, J. A. Life and death decisions by the E2F transcription factors. Curr. Opin. Cell Biol. 19, 649–657 (2007)

    CAS  Article  Google Scholar 

  9. Moon, N. S. et al. Drosophila E2F1 has context-specific pro- and antiapoptotic properties during development. Dev. Cell 9, 463–475 (2005)

    CAS  Article  Google Scholar 

  10. Wikonkal, N. M. et al. Inactivating E2f1 reverts apoptosis resistance and cancer sensitivity in Trp53-deficient mice. Nature Cell Biol. 5, 655–660 (2003)

    CAS  Article  Google Scholar 

  11. Xie, W. et al. Novel link between E2F1 and Smac/DIABLO: proapoptotic Smac/DIABLO is transcriptionally upregulated by E2F1. Nucleic Acids Res. 34, 2046–2055 (2006)

    CAS  Article  Google Scholar 

  12. Berton, T. R., Mitchell, D. L., Guo, R. & Johnson, D. G. Regulation of epidermal apoptosis and DNA repair by E2F1 in response to ultraviolet B radiation. Oncogene 24, 2449–2460 (2005)

    CAS  Article  Google Scholar 

  13. Livesey, F. J. & Cepko, C. L. Vertebrate neural cell-fate determination: lessons from the retina. Nature Rev. Neurosci. 2, 109–118 (2001)

    CAS  Article  Google Scholar 

  14. Chen, D. et al. Rb-mediated neuronal differentiation through cell-cycle-independent regulation of E2f3a. PLoS Biol. 5, e179 (2007)

    Article  Google Scholar 

  15. Dyer, M. A. & Cepko, C. L. Control of Muller glial cell proliferation and activation following retinal injury. Nature Neurosci. 3, 873–880 (2000)

    CAS  Article  Google Scholar 

  16. Claassen, G. F. & Hann, S. R. A role for transcriptional repression of p21CIP1 by c-Myc in overcoming transforming growth factor β-induced cell-cycle arrest. Proc. Natl Acad. Sci. USA 97, 9498–9503 (2000)

    ADS  CAS  Article  Google Scholar 

  17. Alevizopoulos, K., Vlach, J., Hennecke, S. & Amati, B. Cyclin E and c-Myc promote cell proliferation in the presence of p16INK4a and of hypophosphorylated retinoblastoma family proteins. EMBO J. 16, 5322–5333 (1997)

    CAS  Article  Google Scholar 

  18. Santoni-Rugiu, E., Falck, J., Mailand, N., Bartek, J. & Lukas, J. Involvement of Myc activity in a G1/S-promoting mechanism parallel to the pRb/E2F pathway. Mol. Cell. Biol. 20, 3497–3509 (2000)

    CAS  Article  Google Scholar 

  19. DeGregori, J. & Johnson, D. G. Distinct and overlapping roles for E2F family members in transcription, proliferation and apoptosis. Curr. Mol. Med. 6, 739–748 (2006)

    CAS  PubMed  Google Scholar 

  20. Chen, D., Padiernos, E., Ding, F., Lossos, I. S. & Lopez, C. D. Apoptosis-stimulating protein of p53–2 (ASPP2/53BP2L) is an E2F target gene. Cell Death Differ. 12, 358–368 (2005)

    CAS  Article  Google Scholar 

  21. Fogal, V. et al. ASPP1 and ASPP2 are new transcriptional targets of E2F. Cell Death Differ. 12, 369–376 (2005)

    CAS  Article  Google Scholar 

  22. 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)

    CAS  Article  Google Scholar 

  23. Bode, A. M. & Dong, Z. Post-translational modification of p53 in tumorigenesis. Nature Rev. Cancer 4, 793–805 (2004)

    CAS  Article  Google Scholar 

  24. Tang, Y., Zhao, W., Chen, Y., Zhao, Y. & Gu, W. Acetylation is indispensable for p53 activation. Cell 133, 612–626 (2008)

    CAS  Article  Google Scholar 

  25. Wang, C. et al. Interactions between E2F1 and SirT1 regulate apoptotic response to DNA damage. Nature Cell Biol. 8, 1025–1031 (2006)

    CAS  Article  Google Scholar 

  26. Malumbres, M. & Barbacid, M. Cell cycle, CDKs and cancer: a changing paradigm. Nature Rev. Cancer 9, 153–166 (2009)

    CAS  Article  Google Scholar 

  27. Livne-bar, I. et al. Chx10 is required to block photoreceptor differentiation but is dispensable for progenitor proliferation in the postnatal retina. Proc. Natl Acad. Sci. USA 103, 4988–4993 (2006)

    ADS  CAS  Article  Google Scholar 

  28. 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)

    CAS  Article  Google Scholar 

  29. Vaziri, H. et al. hSIR2(SIRT1) functions as an NAD-dependent p53 deacetylase. Cell 107, 149–159 (2001)

    CAS  Article  Google Scholar 

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

    CAS  Article  Google Scholar 

  31. Soriano, P. Generalized lacZ expression with the ROSA26 Cre reporter strain. Nature Genet. 21, 70–71 (1999)

    CAS  Article  Google Scholar 

  32. Leone, G. et al. Myc requires distinct E2F activities to induce S phase and apoptosis. Mol. Cell 8, 105–113 (2001)

    CAS  Article  Google Scholar 

  33. Jonkers, J. et al. Synergistic tumor suppressor activity of BRCA2 and p53 in a conditional mouse model for breast cancer. Nature Genet. 29, 418–425 (2001)

    CAS  Article  Google Scholar 

  34. Knoepfler, P. S., Cheng, P. F. & Eisenman, R. N. N-myc is essential during neurogenesis for the rapid expansion of progenitor cell populations and the inhibition of neuronal differentiation. Genes Dev. 16, 2699–2712 (2002)

    CAS  Article  Google Scholar 

  35. Bracken, A. P., Ciro, M., Cocito, A. & Helin, K. E2F target genes: unraveling the biology. Trends Biochem. Sci. 29, 409–417 (2004)

    CAS  Article  Google Scholar 

  36. Xu, X. et al. A comprehensive ChIP-chip analysis of E2F1, E2F4, and E2F6 in normal and tumor cells reveals interchangeable roles of E2F family members. Genome Res. 17, 1550–1561 (2007)

    CAS  Article  Google Scholar 

  37. Ozono, E. et al. E2F-like elements in p27(Kip1) promoter specifically sense deregulated E2F activity. Genes Cells 14, 89–99 (2009)

    CAS  Article  Google Scholar 

  38. Weinmann, A. S., Bartley, S. M., Zhang, T., Zhang, M. Q. & Farnham, P. J. Use of chromatin immunoprecipitation to clone novel E2F target promoters. Mol. Cell. Biol. 21, 6820–6832 (2001)

    CAS  Article  Google Scholar 

  39. Weinmann, A. S., Yan, P. S., Oberley, M. J., Huang, T. H. & Farnham, P. J. Isolating human transcription factor targets by coupling chromatin immunoprecipitation and CpG island microarray analysis. Genes Dev. 16, 235–244 (2002)

    CAS  Article  Google Scholar 

  40. Christensen, J. et al. Characterization of E2F8, a novel E2F-like cell-cycle regulated repressor of E2F-activated transcription. Nucleic Acids Res. 33, 5458–5470 (2005)

    CAS  Article  Google Scholar 

  41. Lyons, T. E., Salih, M. & Tuana, B. S. Activating E2Fs mediate transcriptional regulation of human E2F6 repressor. Am. J. Physiol. Cell Physiol. 290, C189–C199 (2006)

    CAS  Article  Google Scholar 

  42. Mao, D. Y. et al. Analysis of Myc bound loci identified by CpG island arrays shows that Max is essential for Myc-dependent repression. Curr. Biol. 13, 882–886 (2003)

    CAS  Article  Google Scholar 

  43. Bieda, M., Xu, X., Singer, M. A., Green, R. & Farnham, P. J. Unbiased location analysis of E2F1-binding sites suggests a widespread role for E2F1 in the human genome. Genome Res. 16, 595–605 (2006)

    CAS  Article  Google Scholar 

  44. Kim, J., Chu, J., Shen, X., Wang, J. & Orkin, S. H. An extended transcriptional network for pluripotency of embryonic stem cells. Cell 132, 1049–1061 (2008)

    CAS  Article  Google Scholar 

  45. Zeller, K. I. et al. Global mapping of c-Myc binding sites and target gene networks in human B cells. Proc. Natl Acad. Sci. USA 103, 17834–17839 (2006)

    ADS  CAS  Article  Google Scholar 

  46. Zeller, K. I., Jegga, A. G., Aronow, B. J., O’Donnell, K. A. & Dang, C. V. An integrated database of genes responsive to the Myc oncogenic transcription factor: identification of direct genomic targets. Genome Biol. 4, R69 (2003)

    Article  Google Scholar 

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Acknowledgements

We thank L. van Parijs and R. Weinberg for plasmids; R. Eisenman for mice; L. Penn for advice on Myc; and M. Cayouette and J. Wrana for comments. This work was supported by a grant from the Canadian Institutes for Health Research to R.B. (MOP-74570).

Author Contributions D.C. and R.B. designed the study and interpreted data. D.C. performed all the experiments and was aided in viral and electroporation assays by M.P. P.W., G.L. and P.S.K. provided reagents including mice. R.B. wrote the paper and all authors contributed to editing.

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Correspondence to Rod Bremner.

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Chen, D., Pacal, M., Wenzel, P. et al. Division and apoptosis of E2f-deficient retinal progenitors. Nature 462, 925–929 (2009). https://doi.org/10.1038/nature08544

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