In vivo RNAi screening identifies Pafah1b3 as a target for combination therapy with TKIs in BCR-ABL1+ BCP-ALL.

In vivo RNAi screening identifies Pafah1b3 as a target for combination therapy with TKIs in BCR-ABL1+ BCP-ALL. Blood Adv. 2018 Jun 12;2(11):1229-1242 Authors: Fiedler ERC, Bhutkar A, Lawler E, Besada R, Hemann MT Abstract Despite the addition of tyrosine kinase inhibitors (TKIs) to the treatment of patients with BCR-ABL1+ B-cell precursor acute lymphoblastic leukemia (BCR-ABL1+ BCP-ALL), relapse both with and without BCR-ABL1 mutations is a persistent clinical problem. To identify BCR-ABL1-independent genetic mediators of response to the TKI dasatinib, we performed in vivo and in vitro RNA interference (RNAi) screens in a transplantable syngeneic mouse model of BCR-ABL1+ BCP-ALL. By using a novel combination of a longitudinal screen design and independent component analysis of screening data, we identified hairpins that have distinct behavior in different therapeutic contexts as well as in the in vivo vs in vitro settings. In the set of genes whose loss sensitized BCR-ABL1+ BCP-ALL cells to dasatinib, we identified Pafah1b3, which regulates intracellular levels of platelet-activating factor (PAF), as an in vivo-specific mediator of therapeutic response. Pafah1b3 loss significantly sensitized leukemia cells to the multiple TKIs, indicating that inhibition of PAFAH1B3 in combination with TKI treatment may be an effective therapeutic strategy for BCR-ABL1+ BCP-ALL patients. PAF-induced cell death as well as surface levels of PAF recepto...
Source: Adv Data - Category: Epidemiology Authors: Tags: Blood Adv Source Type: research