Identification of negative feedback regulators in response to acute activation of BCR-ABL1 kinase signaling in MLL-AF4 and E2A-PBX1 acute lymphoblastic leukemia

Human B cell lineage acute lymphoblastic leukemia (ALL) cells carrying MLL-AF4 (SEM; BEL) and E2A-PBX1 (697) gene rearrangements were transduced with the mouse ecotropic receptor to permit subsequent entry of retroviral BCR-ABL1 GFP and GFP empty vectors (EV) pseudotyped with murine ecotropic envelope. GFP expression was measured by flow cytometry. Transductions with BCR-ABL1 GFP and GFP empty vectors (EV) were performed in the presence and absence of 2 mmol/l Imatinib (TKI). Washout of Imatinib in one series of experiments is indicated with an arrow. To study gene expression changes in MLL-AF4 and E2A-PBX1 B cell lineage ALL cells that were transduced with empty vectors (EV), BCR-ABL1 GFP in the presence of Imatinib (BCR-ABL1 OFF), washout of Imatinib (BCR-ABL1 ON) and subsequent re-addition of Imatinib, microarray analyses were performed.

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Shojaee S, Caeser R, Buchner M, Park E, Swaminathan S, Hurtz C, Geng H, Chan LN, Klemm L, Hofmann WK, Qiu YH, Zhang N, Coombes KR, Paietta E, Molkentin J, Koeffler HP, Willman CL, Hunger SP, Melnick A, Kornblau SM, Müschen M