Zeb1 modulates hematopoietic stem cell fates required for suppressing acute myeloid leukemia
Alhomidi Almotiri, … , Florian A. Siebzehnrubl, Neil P. Rodrigues
Alhomidi Almotiri, … , Florian A. Siebzehnrubl, Neil P. Rodrigues
Published October 27, 2020
Citation Information: J Clin Invest. 2021;131(1):e129115. https://doi.org/10.1172/JCI129115.
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Research Article Hematology

Zeb1 modulates hematopoietic stem cell fates required for suppressing acute myeloid leukemia

Abstract

Zeb1, a zinc finger E-box binding homeobox epithelial-mesenchymal transition (EMT) transcription factor, confers properties of “stemness,” such as self-renewal, in cancer. Yet little is known about the function of Zeb1 in adult stem cells. Here, we used the hematopoietic system as a well-established paradigm of stem cell biology to evaluate Zeb1-mediated regulation of adult stem cells. We employed a conditional genetic approach using the Mx1-Cre system to specifically knock out (KO) Zeb1 in adult hematopoietic stem cells (HSCs) and their downstream progeny. Acute genetic deletion of Zeb1 led to rapid-onset thymic atrophy and apoptosis-driven loss of thymocytes and T cells. A profound cell-autonomous self-renewal defect and multilineage differentiation block were observed in Zeb1-KO HSCs. Loss of Zeb1 in HSCs activated transcriptional programs of deregulated HSC maintenance and multilineage differentiation genes and of cell polarity consisting of cytoskeleton-, lipid metabolism/lipid membrane–, and cell adhesion–related genes. Notably, epithelial cell adhesion molecule (EpCAM) expression was prodigiously upregulated in Zeb1-KO HSCs, which correlated with enhanced cell survival, diminished mitochondrial metabolism, ribosome biogenesis, and differentiation capacity and an activated transcriptomic signature associated with acute myeloid leukemia (AML) signaling. ZEB1 expression was downregulated in AML patients, and Zeb1 KO in the malignant counterparts of HSCs — leukemic stem cells (LSCs) — accelerated MLL-AF9– and Meis1a/Hoxa9-driven AML progression, implicating Zeb1 as a tumor suppressor in AML LSCs. Thus, Zeb1 acts as a transcriptional regulator in hematopoiesis, critically coordinating HSC self-renewal, apoptotic, and multilineage differentiation fates required to suppress leukemic potential in AML.

Authors

Alhomidi Almotiri, Hamed Alzahrani, Juan Bautista Menendez-Gonzalez, Ali Abdelfattah, Badi Alotaibi, Lubaid Saleh, Adelle Greene, Mia Georgiou, Alex Gibbs, Amani Alsayari, Sarab Taha, Leigh-anne Thomas, Dhruv Shah, Sarah Edkins, Peter Giles, Marc P. Stemmler, Simone Brabletz, Thomas Brabletz, Ashleigh S. Boyd, Florian A. Siebzehnrubl, Neil P. Rodrigues

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Figure 4

Zeb1 regulates HSC self-renewal and differentiation in a cell-autonomous manner.

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Zeb1 regulates HSC self-renewal and differentiation in a cell-autonomou...
(A) Schematic of secondary HSC transplantation. 300 CD45.2+ HSCs from primary recipients from control or Zeb1–/– mice mixed with 3 × 105 BM competitor cells (CD45.1) were transplanted into lethally irradiated recipients (CD45.1), and the mice were analyzed at week 12. (B) Percentage of donor cells in PB and donor contribution to myeloid (MAC1+), B (B220+), and T (CD4+/CD8+) cells at week 12 after secondary HSC transplantation from control (n = 7) and Zeb1–/– (n = 5) from 2 independent experiments. (C) Schematic of the secondary total BM transplantation in cell-autonomous manner. 5 × 105 CD45.2+ BM cells from primary recipients 14 days after the last pIpC dose from control or Zeb1–/– mice mixed with 5 × 105 BM competitor cells (CD45.1) were transplanted into lethally irradiated recipients (CD45.1), and the mice were analyzed at week 16. (D) Percentage of donor cells in PB and BM at week 16 after secondary cell autonomous total BM transplantation from control (PB n = 5, BM = 6) and Zeb1–/– (PB n = 7, BM = 6) mice from 1 experiment. (E) Donor contribution to PB MAC1+ myeloid cells, B220+ B cells, and CD4+/CD8+ T cells at week 16 after secondary cell-autonomous total BM transplantation from control (n = 5) and Zeb1–/– (n = 7) mice from 1 experiment. Error bars show mean ± SEM. Mann-Whitney U test was used to calculate significance. *P < 0.05; **P < 0.01.