Short Communication | Published:

Inhibiting MYC binding to the E-box DNA motif by ME47 decreases tumour xenograft growth

Oncogene volume 36, pages 68306837 (07 December 2017) | Download Citation

Abstract

Developing therapeutics to effectively inhibit the MYC oncoprotein would mark a key advance towards cancer patient care as MYC is deregulated in over 50% of human cancers. MYC deregulation is correlated with aggressive disease and poor patient outcome. Despite strong evidence in mouse models that inhibiting MYC would significantly impact tumour cell growth and patient survival, traditional approaches have not yet yielded the urgently needed therapeutic agents that directly target MYC. MYC functions through its interaction with MAX to regulate gene transcription by binding to E-box DNA response elements of MYC target genes. Here we used a structure-based strategy to design ME47, a small minimalist hybrid protein (MHP) able to disrupt the MAX:E-box interaction/binding and block transcriptional MYC activity. We show that inducing ME47 expression in established tumour xenografts inhibits tumour growth and decreases cellular proliferation. Mechanistically, we show by chromatin immunoprecipitation that ME47 binds to E-box binding sites of MYC target genes. Moreover, ME47 occupancy decreases MYC:DNA interaction at its cognate E-box binding sites. Taken together, ME47 is a prototypic MHP inhibitor that antagonizes tumour cell growth in vitro and in vivo and inhibits the interaction of MYC with DNA E-box elements. These results support ME47’s role as a MYC inhibitor and suggest that MHPs provide an alternative therapeutic targeting system that can be used to target transcription factors important in human diseases, including cancer.

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References

  1. 1.

    . MYC on the path to cancer. Cell 2012; 149: 22–35.

  2. 2.

    , . The Myc oncoprotein as a therapeutic target for human cancer. Semin Cancer Biol 2006; 16: 318–330.

  3. 3.

    , , , , , et al. Inhibition of Myc family proteins eradicates KRas-driven lung cancer in mice. Genes Dev 2013; 27: 504–513.

  4. 4.

    , . Reflecting on 25 years with MYC. Nat Rev Cancer 2008; 8: 976–990.

  5. 5.

    , . Max: a helix-loop-helix zipper protein that forms a sequence-specific DNA-binding complex with Myc. Science 1991; 251: 1211–1217.

  6. 6.

    , , , . Cancer therapeutics: targeting the dark side of Myc. Eur J Cancer 2005; 41: 2485–2501.

  7. 7.

    , , , , , et al. Modelling Myc inhibition as a cancer therapy. Nature 2008; 455: 679–683.

  8. 8.

    , , . Omomyc expression in skin prevents Myc-induced papillomatosis. Cell Death Differ 2004; 11: 1038–1045.

  9. 9.

    , , , , , et al. Sustained loss of a neoplastic phenotype by brief inactivation of MYC. Science 2002; 297: 102–104.

  10. 10.

    . MYC inactivation elicits oncogene addiction through both tumor cell-intrinsic and host-dependent mechanisms. Genes Cancer 2010; 1: 597–604.

  11. 11.

    , , , , , et al. BET bromodomain inhibition as a therapeutic strategy to target c-Myc. Cell 2011; 146: 904–917.

  12. 12.

    , , , , , et al. Inhibition of BET bromodomains as a therapeutic strategy for cancer drug discovery. Oncotarget 2015; 6: 5501–5516.

  13. 13.

    , , , , , et al. PFI-1, a highly selective protein interaction inhibitor, targeting BET bromodomains. Cancer Res 2013; 73: 3336–3346.

  14. 14.

    , . Strategically targeting MYC in cancer. F1000Res 2016; 5: 408.

  15. 15.

    , , , , , et al. Transcriptional plasticity promotes primary and acquired resistance to BET inhibition. Nature 2015; 525: 543–547.

  16. 16.

    , , , , , et al. Loss of TRIM33 causes resistance to BET bromodomain inhibitors through MYC- and TGF-beta-dependent mechanisms. Proc Natl Acad Sci USA 2016; 113: E4558–E4566.

  17. 17.

    , , , , , et al. BET inhibitor resistance emerges from leukaemia stem cells. Nature 2015; 525: 538–542.

  18. 18.

    , , , , , et al. Perturbation of the c-Myc-Max protein-protein interaction via synthetic alpha-helix mimetics. J Med Chem 2015; 58: 3002–3024.

  19. 19.

    , , , , , et al. Small molecule MYC inhibitor conjugated to integrin-targeted nanoparticles extends survival in a mouse model of disseminated multiple myeloma. Mol Cancer Ther 2015; 14: 1286–1294.

  20. 20.

    . Small-molecule modulators of c-Myc/Max and Max/Max interactions. Curr Top Microbiol Immunol 2011; 348: 139–149.

  21. 21.

    , , , . Small-molecule perturbation of competing interactions between c-Myc and Max. Bioorg Med Chem Lett 2009; 19: 807–810.

  22. 22.

    , , , . Low molecular weight inhibitors of Myc-Max interaction and function. Oncogene 2003; 22: 6151–6159.

  23. 23.

    , , , , , . New structural determinants for c-Myc specific heterodimerization with Max and development of a novel homodimeric c-Myc b-HLH-LZ. J Mol Recognit 2012; 25: 414–426.

  24. 24.

    , , , , , . The Max b-HLH-LZ can transduce into cells and inhibit c-Myc transcriptional activities. PLoS One 2012; 7: e32172.

  25. 25.

    , , , , , . Design and properties of a Myc derivative that efficiently homodimerizes. Oncogene 1998; 17: 2463–2472.

  26. 26.

    , , , , , . Omomyc, a potential Myc dominant negative, enhances Myc-induced apoptosis. Cancer Res 2002; 62: 3507–3510.

  27. 27.

    , , , , . Max-E47, a designed minimalist protein that targets the E-box DNA site in vivo and in vitro. J Am Chem Soc 2009; 131: 7839–7848.

  28. 28.

    , , , , , . Crystal structure of the minimalist Max-E47 protein chimera. PloS One 2012; 7: e32136.

  29. 29.

    , , , , , et al. Cytoplasmic p53 is not required for PUMA-induced apoptosis. Cell Death Differ 2008; 15: 213–215, author reply 215-216.

  30. 30.

    , , , , , et al. IAP antagonists target cIAP1 to induce TNFalpha-dependent apoptosis. Cell 2007; 131: 682–693.

  31. 31.

    , , , , , et al. The action mechanism of the Myc inhibitor termed Omomyc may give clues on how to target Myc for cancer therapy. PloS ONE 2011; 6: e22284.

  32. 32.

    , , , , , et al. MYC activity is negatively regulated by a C-terminal lysine cluster. Oncogene 2013; 33: 1066–1072.

  33. 33.

    , , , , , . New model systems provide insights into Myc-induced transformation. Oncogene 2011; 30: 3727–3734.

  34. 34.

    , , , , , et al. Myc and Omomyc functionally associate with the protein arginine methyltransferase 5 (PRMT5) in glioblastoma cells. Sci Rep 2015; 5: 15494.

  35. 35.

    , , , , , . The kinetics of ER fusion protein activation in vivo. Oncogene 2014; 33: 4877–4880.

  36. 36.

    , , , , , et al. Optimization of experimental design parameters for high-throughput chromatin immunoprecipitation studies. Nucleic Acids Res 2008; 36: e144.

  37. 37.

    , , , , , et al. MYC phosphorylation at novel regulatory regions suppresses transforming activity. Cancer Res 2013; 73: 6504–6515.

  38. 38.

    , , , , , et al. Transcriptional amplification in tumor cells with elevated c-Myc. Cell 2012; 151: 56–67.

  39. 39.

    , , , , , et al. Selective transcriptional regulation by Myc in cellular growth control and lymphomagenesis. Nature 2014; 511: 488–492.

  40. 40.

    , . Targeting transcription factors in cancer. Trends Cancer 2015; 1: 53–65.

  41. 41.

    , . Transcriptional regulation and its misregulation in disease. Cell 2013; 152: 1237–1251.

  42. 42.

    , , , , , et al. Identification of c-MYC SUMOylation by mass spectrometry. PloS One 2014; 9: e115337.

  43. 43.

    , , , . Functional analysis of the N-terminal domain of the Myc oncoprotein. Oncogene 2003; 22: 1998–2010.

  44. 44.

    , , , , , et al. MYC interaction with the tumor suppressive SWI/SNF complex member INI1 regulates transcription and cellular transformation. Cell Cycle 2016; 15: 1–13.

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Acknowledgements

We would like to thank the Penn, Shin, and Chen labs for their helpful reviews and contributions to this manuscript. Special thanks to Dr Peter Mullen, Dr Sam Sathiamoorthy and Peter Tang. Funding was provided by way of Operating grant support from the Collaborative Health Research Program (JS, WC, LZP). Salary and stipend support from the Canadian Research Chairs Program (LZP), Natural Sciences and Engineering Research Council (LCL), Canadian Breast Cancer Foundation Ontario Region Doctoral Fellowship (WBT and MK).

Author information

Affiliations

  1. Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada

    • L C Lustig
    • , D Dingar
    • , W B Tu
    • , C Lourenco
    • , M Kalkat
    • , R Ponzielli
    •  & L Z Penn
  2. Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada

    • W B Tu
    • , C Lourenco
    • , M Kalkat
    •  & L Z Penn
  3. Department of Chemistry, University of Toronto, Toronto, ON, Canada

    • I Inamoto
    •  & J A Shin
  4. Institute of Biomaterials and Biomedical Engineering, University of Toronto, Donnelly Centre for Cellular and Biomolecular Research, Department of Materials Science and Engineering, Department of Chemical Engineering, Toronto, ON, Canada

    • W C W Chan

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The authors declare no conflict of interest.

Corresponding author

Correspondence to L Z Penn.

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DOI

https://doi.org/10.1038/onc.2017.275

Supplementary Information accompanies this paper on the Oncogene website (http://www.nature.com/onc)