The SGI-1776 compound is a FLT3 kinase inhibitor and preferentially induces apoptosis in AML cells harboring a FLT3-IT3 mutation. (A) The FLT3-ITD positive AML cell line MOLM-14 was treated or not with 4μM SGI-1776 or 5nmol/l AC-220 during 1 hour. The FLT3 tyrosine autophosphorylation was then evaluated by FLT3 immunoprecipitation (IP) revealed with an anti–phospho-tyrosine (p-Tyr) antibody as reported.⁷  Whole cell lysates were submitted to Western blot analysis using anti–phospho-Akt S⁴⁷³, ERK Y²⁰²/Y²⁰⁴ and STAT5 Y⁶⁹⁴ antibodies and anti-Akt, ERK, STAT5 and actin antibodies, as reported.⁸  (B) The MOLM-14 (FLT3-ITD) and OCI-AML3 (FLT3-WT) AML cell lines were cultured 48 hours without (CTR histograms) or with 1, 2 or 4μM SGI-1776 (SGI 1, 2 and 4 histograms, respectively), 5nmol/l AC-220 (AC histograms. AC-220 is a specific FLT3 inhibitor) or 25μM LY294002 (LY histograms. LY294002 is a broad-spectrum serine/threonine kinase inhibitor⁹ ). Apoptosis and necrosis were determined by Flow Cytometry as annexin V positive and 7AAD negative and annexin V positive and 7AAD positive AML cells, respectively. (C) The MOLM-14 and OCI-AML3 AML cell lines were cultured 48 hours without or with 1, 2 or 4μM SGI-1776 or 5nmol/l AC-220 and cell lysates were submitted to Western blot using anti-PARP, anti–caspase-3 and anti-actin antibodies.