Fusion of the CRM1 nuclear export receptor to AF10 causes leukemia and transcriptional activation of HOXA genes

• Authors: Waitman Aumann, Emory University; Jessica L Heath, University of Vermont; Amanda E Conway, National Institute of Environmental Health Sciences (NIEHS); Sei-Gyung Kim Sze, Maine Children’s Cancer Program, Scarborough,; Veerain K Gupta, Duke University; Rafi R Kazi, Emory University; Donald R Tope, Emory University; Dan Wechsler, Emory University; Catherine P Lavau, Duke University
• Journal Title: LEUKEMIA
• Volume: Volume 35, Number 3
• Publisher: SPRINGERNATURE | 2020-07-30, Pages 876-880
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1038/s41375-020-0998-3
• Subjects: Environmental Sciences; Health Sciences, Medicine and Surgery
• Keywords: Science & Technology; Life Sciences & Biomedicine; Oncology; Hematology

Abstract

To study leukemogenesis, mice were transplanted with HPCs transduced with fusions using a bicistronic MSCV-IRES-eGFP vector in order to track GFP-positive transduced cells. Both cohorts of CRM1-AF10 (n=13) and CRM1Δ-AF10 (n=8) transplanted mice initially displayed similar percentages of GFP-expressing peripheral blood leukocytes, indicating comparable engraftment (Supplementary Figure 1A). Mice were observed for 450 days, during which 69% of CRM1-AF10 mice developed myeloid leukemia with a median survival of 348 days post-transplant, while 100% of CRM1Δ-AF10 mice developed leukemia with a median survival of 112.5 days post-transplant. In comparison, mice transplanted with CALM-AF10 transduced progenitors developed leukemia within 98 to 200 days (median survival 160 days) (Figure 1D). Of note, mice transplanted with HPCs transduced with either full length wild type CRM1 (n=5) or truncated CRM1Δ (aa 1–1028) (n=5) never developed leukemia (>570 days of observation, data not shown). Both CRM1-AF10 and CRM1Δ-AF10 leukemia mice showed signs of hyperleukocytosis, including splenomegaly (Supplementary Figure 1B) and invasion of bone marrow with GFP-positive leukemia blasts expressing the myeloid markers Mac-1 and Gr-1 (Supplementary Figure 1C). As we have reported for CALM-AF10 leukemia [5], CRM1-AF10 and CRM1Δ-AF10 blasts rarely expressed the pan-B lymphoid marker B220. Leukemic bone marrow blasts from CALM-AF10, CRM1-AF10 or CRM1Δ-AF10 mice expressed similar levels of Hoxa and Meis1 transcripts (Supplementary Figure 1D). Secondary leukemias could be induced by transplanting leukemic blasts recovered from either CRM1-AF10 or CRM1Δ-AF10 leukemic mice (Supplementary Figure 2).