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Apoptosis

Multi-sites cleavage of leukemogenic AML1-ETO fusion protein by caspase-3 and its contribution to increased apoptotic sensitivity

Abstract

Leukemia-associated fusion protein AML1-ETO is a product of the chromosome translocation (8;21) frequently occurred in acute myeloid leukemia (AML). The fusion oncoprotein blocks leukemic cell differentiation, and it also induces growth arrest with increased sensitivity to apoptosis induction. Such dichotomous functions make it difficult to clarify the role of AML1-ETO in leukemogenesis. Here, we systematically showed that constitutively and overexpressed AML1-ETO protein was cleaved to four fragments of 70, 49, 40 and 25 kDa by activated caspase-3 during apoptosis induction by extrinsic mitochondrial and death receptor signaling pathways. The in vitro proteolytic system combined with MALDI-TOF/TOF mass spectrometer confirmed that AML1-ETO and wild-type ETO but not RUNX1 (AML1) proteins were direct substrates of apoptosis executioner caspase-3. Site-directed mutagenesis analyses identified two nonclassical aspartates (TMPD188 and LLLD368) as caspase-3-targeted sites in the AML1-ETO sequence. When these two aspartates were mutated into alanines, more intriguingly, the apoptosis-amplified action of AML1-ETO induction completely disappeared, while inducible expression of the caspase-3-cleaved 70 kDa fragment of AML1-ETO after tetracycline removal is sufficient to enhance apoptotic sensitivity. Further investigations on the potential in vivo effects of such a cleavage and its possible role in leukemogenesis would provide new insights for understanding the biology and treatment of AML1-ETO-associated leukemia.

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References

  1. Bohlander SK . Fusion genes in leukemia: an emerging network. Cytogenet Cell Genet 2000; 91: 52–56.

    Article  CAS  Google Scholar 

  2. Ferrara F, Del Vecchio L . Acute myeloid leukemia with t(8;21)/AML1/ETO: a distinct biological and clinical entity. Haematologica 2002; 87: 306–319.

    CAS  Google Scholar 

  3. Peterson LF, Zhang DE . The 8;21 translocation in leukemogenesis. Oncogene 2004; 23: 4255–4262.

    Article  CAS  Google Scholar 

  4. Nishida S, Hosen N, Shirakata T, Kanato K, Yanagihara M, Nakatsuka S et al. AML1-ETO rapidly induces acute myeloblastic leukemia in cooperation with the Wilms tumor gene, WT1. Blood 2006; 107: 3303–3312.

    Article  CAS  Google Scholar 

  5. Schnittger S, Bacher U, Kern W, Haferlach C, Haferlach T . JAK2 seems to be a typical cooperating mutation in therapy-related t(8;21)/AML1-ETO-positive AML. Leukemia 2007; 21: 183–184.

    Article  CAS  Google Scholar 

  6. Schnittger S, Kohl TM, Haferlach T, Kern W, Hiddemann W, Spiekermann K et al. KIT-D816 mutations in AML1-ETO-positive AML are associated with impaired event-free and overall survival. Blood 2006; 107: 1791–1799.

    Article  CAS  Google Scholar 

  7. Peterson LF, Boyapati A, Ahn EY, Biggs JR, Okumura AJ, Lo MC et al. Acute myeloid leukemia with the 8q22;21q22 translocation: secondary mutational events and alternative t(8;21) transcripts. Blood 2007; 110: 799–805.

    Article  CAS  Google Scholar 

  8. Ahn MY, Huang G, Bae SC, Wee HJ, Kim WY, Ito Y . Negative regulation of granulocytic differentiation in the myeloid precursor cell line 32Dcl3 by ear-2, a mammalian homolog of Drosophila seven-up, and a chimeric leukemogenic gene, AML1/ETO. Proc Natl Acad Sci USA 1998; 95: 1812–1817.

    Article  CAS  Google Scholar 

  9. Kohzaki H, Ito K, Huang G, Wee HJ, Murakami Y, Ito Y . Block of granulocytic differentiation of 32Dcl3 cells by AML1/ETO (MTG8) but not by highly expressed Bcl-2. Oncogene 1999; 18: 4055–4062.

    Article  CAS  Google Scholar 

  10. Tonks A, Tonks AJ, Pearn L, Pearce L, Hoy T, Couzens S et al. Expression of AML1-ETO in human myelomonocytic cells selectively inhibits granulocytic differentiation and promotes their self-renewal. Leukemia 2004; 18: 1238–1245.

    Article  CAS  Google Scholar 

  11. Burel SA, Harakawa N, Zhou L, Pabst T, Tenen DG, Zhang DE . Dichotomy of AML1-ETO functions: growth arrest versus block of differentiation. Mol Cell Biol 2001; 21: 5577–5590.

    Article  CAS  Google Scholar 

  12. Li X, Xu YB, Wang Q, Lu Y, Zheng Y, Wang YC et al. Leukemogenic AML1-ETO fusion protein upregulates expression of connexin 43: the role in AML1-ETO-induced growth arrest in leukemic cells. J Cell Physiol 2006; 208: 594–601.

    Article  CAS  Google Scholar 

  13. Gao FH, Wang Q, Wu YL, Li X, Zhao KW, Chen GQ . c-Jun N-terminal kinase mediates AML1-ETO protein-induced connexin-43 expression. Biochem Biophys Res Commun 2007; 356: 505–511.

    Article  CAS  Google Scholar 

  14. Peterson LF, Yan M, Zhang DE . The p21Waf1 pathway is involved in blocking leukemogenesis by the t(8;21) fusion protein AML1-ETO. Blood 2007; 109: 4392–4398.

    Article  CAS  Google Scholar 

  15. Song MG, Gao SM, Du KM, Xu M, Yu Y, Zhou YH et al. Nanomolar concentration of NSC606985, a camptothecin analog, induces leukemic-cell apoptosis through protein kinase Cdelta-dependent mechanisms. Blood 2005; 105: 3714–3721.

    Article  CAS  Google Scholar 

  16. Lu Y, Xu YB, Yuan TT, Song MG, Lubbert M, Fliegauf M et al. Inducible expression of AML1-ETO fusion protein endows leukemic cells with susceptibility to extrinsic and intrinsic apoptosis. Leukemia 2006; 20: 987–993.

    Article  CAS  Google Scholar 

  17. Zhou GB, Kang H, Wang L, Gao L, Liu P, Xie J et al. Oridonin, a diterpenoid extracted from medicinal herbs, targets AML1-ETO fusion protein and shows potent antitumor activity with low adverse effects on t(8;21) leukemia in vitro and in vivo. Blood 2006; 109: 3441–3450.

    Article  Google Scholar 

  18. Wang L, Zhao WL, Yan JS, Liu P, Sun HP, Zhou GB et al. Eriocalyxin B induces apoptosis of t(8;21) leukemia cells through NF-kappaB and MAPK signaling pathways and triggers degradation of AML1-ETO oncoprotein in a caspase-3-dependent manner. Cell Death Differ 2007; 14: 306–317.

    Article  Google Scholar 

  19. Yang G, Thompson MA, Brandt SJ, Hiebert SW . Histone deacetylase inhibitors induce the degradation of the t(8;21) fusion oncoprotein. Oncogene 2007; 26: 91–101.

    Article  Google Scholar 

  20. Reed JC, Pellecchia M . Apoptosis-based therapies for hematologic malignancies. Blood 2005; 106: 408–418.

    Article  CAS  Google Scholar 

  21. Fliegauf M, Stock M, Berg T, Lubbert M . Williams-Beuren syndrome critical region-5/non-T-cell activation linker: a novel target gene of AML1/ETO. Oncogene 2004; 23: 9070–9081.

    Article  CAS  Google Scholar 

  22. Meyers S, Lenny N, Hiebert SW . The t(8;21) fusion protein interferes with AML-1B-dependent transcriptional activation. Mol Cell Biol 1995; 15: 1974–1982.

    Article  CAS  Google Scholar 

  23. Lee KK, Ohyama T, Yajima N, Tsubuki S, Yonehara S . MST, a physiological caspase substrate, highly sensitizes apoptosis both upstream and downstream of caspase activation. J Biol Chem 2001; 276: 19276–19285.

    Article  CAS  Google Scholar 

  24. Zhao KW, Li X, Zhao Q, Huang Y, Li D, Peng ZG et al. Protein kinase Cdelta mediates retinoic acid and phorbol myristate acetate-induced phospholipid scramblase 1 gene expression: its role in leukemic cell differentiation. Blood 2004; 104: 3731–3738.

    Article  CAS  Google Scholar 

  25. Schimmer AD, Hedley DW, Penn LZ, Minden MD . Receptor- and mitochondrial-mediated apoptosis in acute leukemia: a translational view. Blood 2001; 98: 3541–3553.

    Article  CAS  Google Scholar 

  26. Asou H, Tashiro S, Hamamoto K, Otsuji A, Kita K, Kamada N . Establishment of a human acute myeloid leukemia cell line (Kasumi-1) with 8;21 chromosome translocation. Blood 1991; 77: 2031–2036.

    CAS  Google Scholar 

  27. Matozaki S, Nakagawa T, Kawaguchi R, Aozaki R, Tsutsumi M, Murayama T et al. Establishment of a myeloid leukaemic cell line (SKNO-1) from a patient with t(8;21) who acquired monosomy 17 during disease progression. Br J Haematol 1995; 89: 805–811.

    Article  CAS  Google Scholar 

  28. Zhan Q, Jin S, Ng B, Plisket J, Shangary S, Rathi A et al. Caspase-3 mediated cleavage of BRCA1 during UV-induced apoptosis. Oncogene 2002; 21: 5335–5345.

    Article  CAS  Google Scholar 

  29. Fischer U, Janicke RU, Schulze-Osthoff K . Many cuts to ruin: a comprehensive update of caspase substrates. Cell Death Differ 2003; 10: 76–100.

    Article  CAS  Google Scholar 

  30. Boer J, Bonten-Surtel J, Grosveld G . Overexpression of the nucleoporin CAN/NUP214 induces growth arrest, nucleocytoplasmic transport defects, and apoptosis. Mol Cell Biol 1998; 18: 1236–1247.

    Article  CAS  Google Scholar 

  31. Cande C, Cecconi F, Dessen P, Kroemer G . Apoptosis-inducing factor (AIF): key to the conserved caspase-independent pathways of cell death? J Cell Sci 2002; 115: 4727–4734.

    Article  CAS  Google Scholar 

  32. Licht JD . AML1 and the AML1-ETO fusion protein in the pathogenesis of t(8;21) AML. Oncogene 2001; 20: 5660–5679.

    Article  CAS  Google Scholar 

  33. Sakahira H, Enari M, Nagata S . Cleavage of CAD inhibitor in CAD activation and DNA degradation during apoptosis. Nature 1998; 391: 96–99.

    Article  CAS  Google Scholar 

  34. Bloomfield CD, Lawrence D, Byrd JC, Carroll A, Pettenati MJ, Tantravahi R et al. Frequency of prolonged remission duration after high-dose cytarabine intensification in acute myeloid leukemia varies by cytogenetic subtype. Cancer Res 1998; 58: 4173–4179.

    CAS  Google Scholar 

  35. Arama E, Agapite J, Steller H . Caspase activity and a specific cytochrome C are required for sperm differentiation in Drosophila. Dev Cell 2003; 4: 687–697.

    Article  CAS  Google Scholar 

  36. Fernando P, Brunette S, Megeney LA . Neural stem cell differentiation is dependent upon endogenous caspase 3 activity. FASEB J 2005; 19: 1671–1673.

    Article  CAS  Google Scholar 

  37. Miura M, Chen XD, Allen MR, Bi Y, Gronthos S, Seo BM et al. A crucial role of caspase-3 in osteogenic differentiation of bone marrow stromal stem cells. J Clin Invest 2004; 114: 1704–1713.

    Article  CAS  Google Scholar 

  38. Schwerk C, Schulze-Osthoff K . Non-apoptotic functions of caspases in cellular proliferation and differentiation. Biochem Pharmacol 2003; 66: 1453–1458.

    Article  CAS  Google Scholar 

  39. Lui JC, Kong SK . Erythropoietin activates caspase-3 and downregulates CAD during erythroid differentiation in TF-1 cells—a protection mechanism against DNA fragmentation. FEBS Lett 2006; 580: 1965–1970.

    Article  CAS  Google Scholar 

  40. Yan M, Burel SA, Peterson LF, Kanbe E, Iwasaki H, Boyapati A et al. Deletion of an AML1-ETO C-terminal NcoR/SMRT-interacting region strongly induces leukemia development. Proc Natl Acad Sci USA 2004; 101: 17186–17191.

    Article  CAS  Google Scholar 

  41. Yan M, Kanbe E, Peterson LF, Boyapati A, Miao Y, Wang Y et al. A previously unidentified alternatively spliced isoform of t(8;21) transcript promotes leukemogenesis. Nat Med 2006; 12: 945–949.

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We appreciate Dr Lübbert M, Dr Tenen DG and Dr Hiebert SW for providing us U937-A/E 9/14/18, U937T cell line and some plasmids, respectively. This work was supported in part by National Key Program (973) for Basic Research of China (NO2002CB512805), National Natural Science Foundation (30500257, 30630034), Grants from Science and Technology Committee of Shanghai (05JC14032). Dr. GQ Chen is a Chang Jiang Scholar of Ministry of Education of China, and is supported by Shanghai Ling-Jun Talent Program.

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Lu, Y., Peng, ZG., Yuan, TT. et al. Multi-sites cleavage of leukemogenic AML1-ETO fusion protein by caspase-3 and its contribution to increased apoptotic sensitivity. Leukemia 22, 378–386 (2008). https://doi.org/10.1038/sj.leu.2405020

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