A noncanonical Flt3ITD/NF-κB signaling pathway represses DAPK1 in acute myeloid leukemia

Rajasubramaniam Shanmugam, Padmaja Gade, Annique Wilson-Weekes, Hamid Sayar, Attaya Suvannasankha, Chirayu Goswami, Lang Li, Sushil Gupta, Angelo A. Cardoso, Tareq Al Baghdadi, Katie J. Sargent, Larry D. Cripe, Dhananjaya V. Kalvakolanu, H. Scott Boswell

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Abstract

Purpose: Death-associated protein kinase 1 (DAPK1), a tumor suppressor, is a rate-limiting effector in an endoplasmic reticulum (ER) stress-dependent apoptotic pathway. Its expression is epigenetically suppressed in several tumors. Amechanistic basis for epigenetic/transcriptional repression of DAPK1 was investigated in certain forms of acute myeloid leukemia (AML) with poor prognosis, which lacked ER stress-induced apoptosis. Experimental Design: Heterogeneous primary AMLs were screened to identify a subgroup with Flt3ITD in which repression of DAPK1, among NF-κB - and c-Jun-responsive genes, was studied. RNA interference knockdown studies were carried out in an Flt3ITD + cell line, MV-4-11, to establish genetic epistasis in the pathway Flt3ITD-TAK1-DAPK1 repression, and chromatin immunoprecipitations were carried out to identify proximate effector proteins, including TAK1-activated p52NF-κB, at the DAPK1 locus. Results: AMLs characterized by normal karyotype with Flt3ITD were found to have 10- to 100-fold lower DAPK1 transcripts normalized to the expression of c-Jun, a transcriptional activator of DAPK1, as compared with a heterogeneous cytogenetic category. In addition, Meis1, a c-Jun-responsive adverse AML prognostic gene signature was measured as control. These Flt3ITD + AMLs overexpress relB, a transcriptional repressor, which forms active heterodimers with p52NF-κB. Chromatin immunoprecipitation assays identified p52NF-κB binding to the DAPK1 promoter together with histone deacetylase 2 (HDAC2) and HDAC6 in the Flt3ITD + human AML cell line MV-4-11. Knockdown of p52NF-κB or its upstream regulator, NF-κB-inducing kinase (NIK), de-repressed DAPK1. DAPK1-repressed primary Flt3ITD + AMLs had selective nuclear activation of p52NF-κB. Conclusions: Flt3ITD promotes a noncanonical pathway via TAK1 and p52NF-κB to suppress DAPK1 in association with HDACs, which explains DAPK1 repression in Flt3ITD + AML.

Original languageEnglish (US)
Pages (from-to)360-369
Number of pages10
JournalClinical Cancer Research
Volume18
Issue number2
DOIs
StatePublished - Jan 15 2012

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ASJC Scopus subject areas

  • Oncology
  • Cancer Research

Cite this

Shanmugam, R., Gade, P., Wilson-Weekes, A., Sayar, H., Suvannasankha, A., Goswami, C., Li, L., Gupta, S., Cardoso, A. A., Al Baghdadi, T., Sargent, K. J., Cripe, L. D., Kalvakolanu, D. V., & Boswell, H. S. (2012). A noncanonical Flt3ITD/NF-κB signaling pathway represses DAPK1 in acute myeloid leukemia. Clinical Cancer Research, 18(2), 360-369. https://doi.org/10.1158/1078-0432.CCR-10-3022