@article{435d93260938451a9b9f2f8994b885a0,
title = "Loss of glucocorticoid receptor expression mediates in vivo dexamethasone resistance in T-cell acute lymphoblastic leukemia",
abstract = "Despite decades of clinical use, mechanisms of glucocorticoid resistance are poorly understood. We treated primary murine T lineage acute lymphoblastic leukemias (T-ALLs) with the glucocorticoid dexamethasone (DEX) alone and in combination with the pan-PI3 kinase inhibitor GDC-0941 and observed a robust response to DEX that was modestly enhanced by GDC-0941. Continuous in vivo treatment invariably resulted in outgrowth of drug-resistant clones, ~30% of which showed markedly reduced glucocorticoid receptor (GR) protein expression. A similar proportion of relapsed human T-ALLs also exhibited low GR protein levels. De novo or preexisting mutations in the gene encoding GR (Nr3c1) occurred in relapsed clones derived from multiple independent parental leukemias. CRISPR/Cas9 gene editing confirmed that loss of GR expression confers DEX resistance. Exposing drug-sensitive T-ALLs to DEX in vivo altered transcript levels of multiple genes, and this response was attenuated in relapsed T-ALLs. These data implicate reduced GR protein expression as a frequent cause of glucocorticoid resistance in T-ALL.",
author = "Wandler, {Anica M.} and Huang, {Benjamin J.} and Craig, {Jeffrey W.} and Kathryn Hayes and Hannah Yan and Meyer, {Lauren K.} and Alessandro Scacchetti and Gabriela Monsalve and Monique Dail and Qing Li and Wong, {Jasmine C.} and Olga Weinberg and Hasserjian, {Robert P.} and Kogan, {Scott C.} and Philip Jonsson and Keith Yamamoto and Deepak Sampath and Joy Nakitandwe and Downing, {James R.} and Jinghui Zhang and Aster, {Jon C.} and Taylor, {Barry S.} and Kevin Shannon",
note = "Funding Information: Committee, and an Alex{\textquoteright}s Lemonade Stand Foundation Young Investigator Grant including support from Northwestern Mutual. KS is an American Cancer Society Research Professor (RP 10-078-01-TBE). Funding Information: Acknowledgements We thank members of the Integrated Genomics Operation in the Marie-Josee and Henry R. Kravis Center for Molecular Oncology at the Memorial Sloan-Kettering Cancer Center, and the Genome Sequencing Lab at St. Jude Children{\textquoteright}s Research Hospital for assistance with sequencing; the UCSF Biorepository and Tissue Biomarker Technology Core and the DF/HCC Research Pathology Cores at Harvard Medical School for performing immunohistochemistry analysis. This study was supported in part by the UCSF Helen Diller Family Comprehensive Cancer Center Laboratory for Cell Analysis Shared Resource Facility through a grant from the NIH (P30CA082103). We obtained KrasG12D mice from David Tuveson and Tyler Jacks, and Linda Wolff provided the MOL4070LTR retrovirus. This work was supported in part by National Institutes of Health awards R37 CA72614 (KS), R01 CA180037 (KS); P30 CA008748, U54 OD020355 (BST), R01 CA204749 (BST), and awards from the St. Baldrick{\textquoteright}s Foundation (KS), the American Cancer Society (RSG-15-067-01-TBG) (KS), the Anna Fuller Fund, and the Robertson Foundation (BST). AMW was supported by a Postdoctoral Fellowship (PF-14-070-01-TBG) from the American Cancer Society including a supplement from the Hillcrest Publisher Copyright: {\textcopyright} 2020, The Author(s), under exclusive licence to Springer Nature Limited.",
year = "2020",
month = aug,
day = "1",
doi = "10.1038/s41375-020-0748-6",
language = "English (US)",
volume = "34",
pages = "2025--2037",
journal = "Leukemia",
issn = "0887-6924",
publisher = "Nature Publishing Group",
number = "8",
}