TY - JOUR
T1 - DOT1L Is a Novel Cancer Stem Cell Target for Triple-Negative Breast Cancer
AU - Kurani, Hetakshi
AU - Razavipour, Seyedeh Fatemeh
AU - Harikumar, Kuzhuvelil B.
AU - Dunworth, Matthew
AU - Ewald, Andrew J.
AU - Nasir, Apsra
AU - Pearson, Gray
AU - Van Booven, Derek
AU - Zhou, Zhiqun
AU - Azzam, Diana
AU - Wahlestedt, Claes
AU - Slingerland, Joyce
N1 - Funding Information:
This work was supported by grant W81XWH-15-1-0581 from the US Department of Defense Breast Cancer Research Program to J. Slingerland and C. Wahlestedt and by a Breast Cancer Research Foundation grant to AJE (BCRF-21-048). EPZ-P5676 was provided for these studies by Epizyme. Epizyme did not provide any funding for this work. We thank Lluis Morey, Maria Figueroa, and Ralf Landgraf for useful discussions. We acknowledge the Imaging Core at Lombardi Comprehensive Cancer Center at Georgetown University, the Flow Cytometry Shared Resources at both Lombardi and Sylvester Comprehensive Cancer Centers and the Onco-Genomics Shared Resource at Sylvester Comprehensive Center Center, and the Research Informatics Core of the JP Hussman Institute for Human Genomics at University of Miami Miller School of Medicine.
Funding Information:
A.J. Ewald reports grants from the Breast Cancer Research Foundation during the conduct of the study; other support from Immunocore outside the submitted work; in addition, A.J. Ewald has a patent for US20140336282A1 issued and a patent for WO2016183183A1 pending. G. Pearson reports grants from the NIH during the conduct of the study. No disclosures were reported by the other authors.
Publisher Copyright:
© 2022 The Authors; Published by the American Association for Cancer Research
PY - 2022/5/1
Y1 - 2022/5/1
N2 - Purpose: Although chemotherapies kill most cancer cells, stem cell–enriched survivors seed metastasis, particularly in triple-negative breast cancers (TNBC). TNBCs arise from and are enriched for tumor stem cells. Here, we tested if inhibition of DOT1L, an epigenetic regulator of normal tissue stem/progenitor populations, would target TNBC stem cells. Experimental Design: Effects of DOT1L inhibition by EPZ-5676 on stem cell properties were tested in three TNBC lines and four patient-derived xenograft (PDX) models and in isolated cancer stem cell (CSC)-enriched ALDH1+ and ALDH1- populations. RNA sequencing compared DOT1L regulated pathways in ALDH1+ and ALDH1- cells. To test if EPZ-5676 decreases CSC in vivo, limiting dilution assays of EPZ-5676/vehicle pretreated ALDH1+ and ALDH1- cells were performed. Tumor latency, growth, and metastasis were evaluated. Antitumor activity was also tested in TNBC PDX and PDX-derived organoids. Results: ALDH1+ TNBC cells exhibit higher DOT1L and H3K79me2 than ALDH1-. DOT1L maintains MYC expression and self-renewal in ALDH1+ cells. Global profiling revealed that DOT1L governs oxidative phosphorylation, cMyc targets, DNA damage response, and WNT activation in ALDH1+ but not in ALDH1- cells. EPZ-5676 reduced tumorspheres and ALDH1+ cells in vitro and decreased tumor-initiating stem cells and metastasis in xenografts generated from ALDH1+ but not ALDH1- populations in vivo. EPZ-5676 significantly reduced growth in vivo of one of two TNBC PDX tested and decreased clonogenic 3D growth of two other PDX-derived organoid cultures. Conclusions: DOT1L emerges as a key CSC regulator in TNBC. Present data support further clinical investigation of DOT1L inhibitors to target stem cell–enriched TNBC.
AB - Purpose: Although chemotherapies kill most cancer cells, stem cell–enriched survivors seed metastasis, particularly in triple-negative breast cancers (TNBC). TNBCs arise from and are enriched for tumor stem cells. Here, we tested if inhibition of DOT1L, an epigenetic regulator of normal tissue stem/progenitor populations, would target TNBC stem cells. Experimental Design: Effects of DOT1L inhibition by EPZ-5676 on stem cell properties were tested in three TNBC lines and four patient-derived xenograft (PDX) models and in isolated cancer stem cell (CSC)-enriched ALDH1+ and ALDH1- populations. RNA sequencing compared DOT1L regulated pathways in ALDH1+ and ALDH1- cells. To test if EPZ-5676 decreases CSC in vivo, limiting dilution assays of EPZ-5676/vehicle pretreated ALDH1+ and ALDH1- cells were performed. Tumor latency, growth, and metastasis were evaluated. Antitumor activity was also tested in TNBC PDX and PDX-derived organoids. Results: ALDH1+ TNBC cells exhibit higher DOT1L and H3K79me2 than ALDH1-. DOT1L maintains MYC expression and self-renewal in ALDH1+ cells. Global profiling revealed that DOT1L governs oxidative phosphorylation, cMyc targets, DNA damage response, and WNT activation in ALDH1+ but not in ALDH1- cells. EPZ-5676 reduced tumorspheres and ALDH1+ cells in vitro and decreased tumor-initiating stem cells and metastasis in xenografts generated from ALDH1+ but not ALDH1- populations in vivo. EPZ-5676 significantly reduced growth in vivo of one of two TNBC PDX tested and decreased clonogenic 3D growth of two other PDX-derived organoid cultures. Conclusions: DOT1L emerges as a key CSC regulator in TNBC. Present data support further clinical investigation of DOT1L inhibitors to target stem cell–enriched TNBC.
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U2 - 10.1158/1078-0432.CCR-21-1299
DO - 10.1158/1078-0432.CCR-21-1299
M3 - Article
C2 - 35135840
AN - SCOPUS:85128222860
SN - 1078-0432
VL - 28
SP - 1948
EP - 1965
JO - Clinical Cancer Research
JF - Clinical Cancer Research
IS - 9
ER -