Bell, C.C.Fennell, K.A.Chan, Y.C.Rambow, F.Yeung, M.M.Vassiliadis, D.Lara, L.Yeh, P.Martelotto, L.G.Rogiers, A.Kremer, B.E.Barbash, O.Mohammad, H.P.Johanson, T.M.Burr, M.L.Dhar, A.Karpinich, N.Tian, L.Tyler, D.S.MacPherson, L.et al.2022-03-072022-03-072019Nature Communications, 2019; 10(1):2723-1-2723-152041-17232041-1723https://hdl.handle.net/2440/134548Non-genetic drug resistance is increasingly recognised in various cancers. Molecular insights into this process are lacking and it is unknown whether stable non-genetic resistance can be overcome. Using single cell RNA-sequencing of paired drug naïve and resistant AML patient samples and cellular barcoding in a unique mouse model of non-genetic resistance, here we demonstrate that transcriptional plasticity drives stable epigenetic resistance. With a CRISPR-Cas9 screen we identify regulators of enhancer function as important modulators of the resistant cell state. We show that inhibition of Lsd1 (Kdm1a) is able to overcome stable epigenetic resistance by facilitating the binding of the pioneer factor, Pu.1 and cofactor, Irf8, to nucleate new enhancers that regulate the expression of key survival genes. This enhancer switching results in the re-distribution of transcriptional co-activators, including Brd4, and provides the opportunity to disable their activity and overcome epigenetic resistance. Together these findings highlight key principles to help counteract non-genetic drug resistance.en© The Author(s) 2019. Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Drug resistanceCell Line, TumorBone MarrowAnimalsMice, Inbred C57BLHumansMiceTrans-ActivatorsAntineoplastic AgentsTreatment OutcomeXenograft Model Antitumor AssaysSequence Analysis, RNATranscription, GeneticEpigenesis, GeneticGene Expression Regulation, LeukemicDrug Resistance, NeoplasmFemaleLeukemia, Myeloid, AcuteKaplan-Meier EstimateHEK293 CellsSingle-Cell AnalysisCRISPR-Cas SystemsJournal article10.1038/s41467-019-10652-92022-03-07600357Martelotto, L.G. [0000-0002-9625-1183]