Acute myeloid leukemia (AML) with the FLT3 internal tandem duplication (FLT3-ITD AML) accounts for 20–30% of AML cases. This subtype usually responds poorly to conventional therapies, and might become resistant to FLT3 tyrosine kinase inhibitors (TKIs) due to molecular bypass mechanisms. New therapeutic strategies focusing on resistance mechanisms are therefore urgently needed. Pim kinases are FLT3-ITD oncogenic targets that have been implicated in FLT3 TKI resistance. However, their precise biological function downstream of FLT3-ITD requires further investigation. We performed high-throughput transcriptomic and proteomic analyses in Pim2-depleted FLT3-ITD AML cells and found that Pim2 predominantly controlled apoptosis through Bax expression and mitochondria disruption. We identified ribosomal protein S6 kinase A3 (RSK2), a 90 kDa serine/threonine kinase involved in the mitogen-activated protein kinase cascade encoded by the RPS6KA3 gene, as a novel Pim2 target. Ectopic expression of an RPS6KA3 allele rescued the viability of Pim2-depleted cells, supporting the involvement of RSK2 in AML cell survival downstream of Pim2. Finally, we showed that RPS6KA3 knockdown reduced the propagation of human AML cells in vivo in mice. Our results point to RSK2 as a novel Pim2 target with translational therapeutic potential in FLT3-ITD AML.
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Patel JP, Gonen M, Figueroa ME, Fernandez H, Sun Z, Racevskis J et al. Prognostic relevance of integrated genetic profiling in acute myeloid leukemia. N Engl J Med 2012; 366: 1079–1089.
Leung AY, Man CH, Kwong YL . FLT3 inhibition: a moving and evolving target in acute myeloid leukaemia. Leukemia 2013; 27: 260–268.
Grunwald MR, Levis MJ . FLT3 tyrosine kinase inhibition as a paradigm for targeted drug development in acute myeloid leukemia. Semin Hematol 2015; 52: 193–199.
Rollig C, Serve H, Huttmann A, Noppeney R, Muller-Tidow C, Krug U et al. Addition of sorafenib versus placebo to standard therapy in patients aged 60 years or younger with newly diagnosed acute myeloid leukaemia (SORAML): a multicentre, phase 2, randomised controlled trial. Lancet Oncol 2015; 16: 1691–1699.
Stone RM, Mandrekar SJ, Sanford BL, Laumann K, Geyer S, Bloomfield CD et al. Midostaurin plus chemotherapy for acute myeloid leukemia with a FLT3 mutation. N Engl J Med 2017; 377: 454–464.
Green AS, Maciel TT, Hospital MA, Yin C, Mazed F, Townsend EC et al. Pim kinases modulate resistance to FLT3 tyrosine kinase inhibitors in FLT3-ITD acute myeloid leukemia. Sci Adv 2015; 1: e1500221.
Brault L, Gasser C, Bracher F, Huber K, Knapp S, Schwaller J . PIM serine/threonine kinases in the pathogenesis and therapy of hematologic malignancies and solid cancers. Haematologica 2010; 95: 1004–1015.
Tamburini J, Green AS, Bardet V, Chapuis N, Park S, Willems L et al. Protein synthesis is resistant to rapamycin and constitutes a promising therapeutic target in acute myeloid leukemia. Blood 2009; 114: 1618–1627.
Grundler R, Brault L, Gasser C, Bullock AN, Dechow T, Woetzel S et al. Dissection of PIM serine/threonine kinases in FLT3-ITD-induced leukemogenesis reveals PIM1 as regulator of CXCL12-CXCR4-mediated homing and migration. J Exp Med 2009; 206: 1957–1970.
Chen LS, Redkar S, Taverna P, Cortes JE, Gandhi V . Mechanisms of cytotoxicity to Pim kinase inhibitor, SGI-1776, in acute myeloid leukemia. Blood 2011; 118: 693–702.
Guo Z, Wang A, Zhang W, Levit M, Gao Q, Barberis C et al. PIM inhibitors target CD25-positive AML cells through concomitant suppression of STAT5 activation and degradation of MYC oncogene. Blood 2014; 124: 1777–1789.
Hospital MA, Green AS, Lacombe C, Mayeux P, Bouscary D, Tamburini J . The FLT3 and Pim kinases inhibitor SGI-1776 preferentially target FLT3-ITD AML cells. Blood 2012; 119: 1791–1792.
Keeton EK, McEachern K, Dillman KS, Palakurthi S, Cao Y, Grondine MR et al. AZD1208, a potent and selective pan-Pim kinase inhibitor, demonstrates efficacy in preclinical models of acute myeloid leukemia. Blood 2014; 123: 905–913.
Garcia PD, Langowski JL, Wang Y, Chen M, Castillo J, Fanton C et al. Pan-PIM kinase inhibition provides a novel therapy for treating hematologic cancers. Clin Cancer Res 20: 1834–1845.
Chesnais V, Arcangeli ML, Delette C, Rousseau A, Guermouche H, Lefevre C et al. Architectural and functional heterogeneity of hematopoietic stem/progenitor cells in non-del(5q) myelodysplastic syndromes. Blood 2017; 129: 484–496.
Wiederschain D, Wee S, Chen L, Loo A, Yang G, Huang A et al. Single-vector inducible lentiviral RNAi system for oncology target validation. Cell Cycle 2009; 8: 498–504.
Sujobert P, Poulain L, Paubelle E, Zylbersztejn F, Grenier A, Lambert M et al. Co-activation of AMPK and mTORC1 induces cytotoxicity in acute myeloid leukemia. Cell Rep 2015; 11: 1446–1457.
Meerbrey KL, Hu G, Kessler JD, Roarty K, Li MZ, Fang JE et al. The pINDUCER lentiviral toolkit for inducible RNA interference in vitro and in vivo. Proc Natl Acad Sci USA 2011; 108: 3665–3670.
Gautier EF, Ducamp S, Leduc M, Salnot V, Guillonneau F, Dussiot M et al. Comprehensive proteomic analysis of human erythropoiesis. Cell Rep 2016; 16: 1470–1484.
Vizcaino JA, Csordas A, del-Toro N, Dianes JA, Griss J, Lavidas I et al2016 2016 update of the PRIDE database and its related tools. Nucleic Acids Res 2016; 44: D447–D456.
Saland E, Boutzen H, Castellano R, Pouyet L, Griessinger E, Larrue C et al. A robust and rapid xenograft model to assess efficacy of chemotherapeutic agents for human acute myeloid leukemia. Blood Cancer J 2015; 5: e297.
Zheng JH, Viacava Follis A, Kriwacki RW, Moldoveanu T . Discoveries and controversies in BCL-2 protein-mediated apoptosis. FEBS J 2015; 283: 2690–2700.
Certo M, Del Gaizo Moore V, Nishino M, Wei G, Korsmeyer S, Armstrong SA et al. Mitochondria primed by death signals determine cellular addiction to antiapoptotic BCL-2 family members. Cancer Cell 2006; 9: 351–365.
Elf S, Blevins D, Jin L, Chung TW, Williams IR, Lee BH et al. p90RSK2 is essential for FLT3-ITD- but dispensable for BCR-ABL-induced myeloid leukemia. Blood 2011; 117: 6885–6894.
Garcia PD, Langowski JL, Wang Y, Chen M, Castillo J, Fanton C et al. Pan-PIM kinase inhibition provides a novel therapy for treating hematologic cancers. Clin Cancer Res 2014; 20: 1834–1845.
Zippo A, De Robertis A, Serafini R, Oliviero S . PIM1-dependent phosphorylation of histone H3 at serine 10 is required for MYC-dependent transcriptional activation and oncogenic transformation. Nat Cell Biol 2007; 9: 932–944.
Hogan C, Hutchison C, Marcar L, Milne D, Saville M, Goodlad J et al. Elevated levels of oncogenic protein kinase Pim-1 induce the p53 pathway in cultured cells and correlate with increased Mdm2 in mantle cell lymphoma. J Biol Chem 2008; 283: 18012–18023.
Miyashita T, Reed JC . Tumor suppressor p53 is a direct transcriptional activator of the human bax gene. Cell 1995; 80: 293–299.
Cohen MS, Zhang C, Shokat KM, Taunton J . Structural bioinformatics-based design of selective, irreversible kinase inhibitors. Science 2005; 308: 1318–1321.
Dufresne SD, Bjorbaek C, El-Haschimi K, Zhao Y, Aschenbach WG, Moller DE et al. Altered extracellular signal-regulated kinase signaling and glycogen metabolism in skeletal muscle from p90 ribosomal S6 kinase 2 knockout mice. Mol cell biol 2001; 21: 81–87.
Papaemmanuil E, Gerstung M, Bullinger L, Gaidzik VI, Paschka P, Roberts ND et al. Genomic classification and prognosis in acute myeloid leukemia. N Engl J Med 2016; 374: 2209–2221.
Santos FP, Jones D, Qiao W, Cortes JE, Ravandi F, Estey EE et al. Prognostic value of FLT3 mutations among different cytogenetic subgroups in acute myeloid leukemia. Cancer 2011; 117: 2145–2155.
Daver N, Cortes J, Ravandi F, Patel KP, Burger JA, Konopleva M et al. Secondary mutations as mediators of resistance to targeted therapy in leukemia. Blood 2015; 125: 3236–3245.
Larrue C, Saland E, Boutzen H, Vergez F, David M, Joffre C et al. Proteasome inhibitors induce FLT3-ITD degradation through autophagy in AML cells. Blood 2016; 127: 882–892.
Sexauer A, Perl A, Yang X, Borowitz M, Gocke C, Rajkhowa T et al. Terminal myeloid differentiation in vivo is induced by FLT3 inhibition in FLT3/ITD AML. Blood 2012; 120: 4205–4214.
del Peso L, Gonzalez-Garcia M, Page C, Herrera R, Nunez G . Interleukin-3-induced phosphorylation of BAD through the protein kinase Akt. Science 1997; 278: 687–689.
Kang S, Chen J . Targeting RSK2 in human malignancies. Expert Opin Ther Targets 2011; 15: 11–20.
Kang S, Dong S, Gu TL, Guo A, Cohen MS, Lonial S et al. FGFR3 activates RSK2 to mediate hematopoietic transformation through tyrosine phosphorylation of RSK2 and activation of the MEK/ERK pathway. Cancer Cell 2007; 12: 201–214.
Ludwik KA, Campbell JP, Li M, Li Y, Sandusky ZM, Pasic L et al. Development of a RSK inhibitor as a novel therapy for triple-negative breast cancer. Mol Cancer Therapeut 2016; 15: 2598–2608.
Jain R, Mathur M, Lan J, Costales A, Atallah G, Ramurthy S et al. Discovery of potent and selective RSK inhibitors as biological probes. J Med Chem 2015; 58: 6766–6783.
This work was supported by grants from the Institut National du Cancer (Projet Recherche Translationnelle TRANSLA13-087) and from the Ligue Nationale Contre le Cancer (Equipe Labellisée EL2014; Projet R14077KK).
Contribution: M-AH, AJ, FM, JM, RB, ASG, ML, JD, LP and NJ performed in vitro experiments; ES and CL performed in vivo experiments; E-FG, VS and MLG performed proteomic experiments; OK and MF performed sequencing experiments; PS analyzed the results and wrote the paper; CR, PA, PM and DB analyzed the results; J-ES designed the in vivo research and wrote the paper; JT designed the research, made the figures and wrote the paper.
The authors declare no conflict of interest.
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Hospital, MA., Jacquel, A., Mazed, F. et al. RSK2 is a new Pim2 target with pro-survival functions in FLT3-ITD-positive acute myeloid leukemia. Leukemia 32, 597–605 (2018). https://doi.org/10.1038/leu.2017.284
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