Retroviral insertional mutagenesis identifies Zeb2 activation as a novel leukemogenic collaborating event in CALM-AF10 transgenic mice.
The t(10;11) translocation results in a CALM-AF10 fusion gene in a subset of leukemia patients. Expression of a CALM-AF10 transgene results in leukemia, with prolonged latency and incomplete penetrance, suggesting that additional events are necessary for leukemic transformation. CALM-AF10 mice infected with the MOL4070LTR retrovirus developed acute leukemia, and ligation-mediated polymerase chain reaction was used to identify retroviral insertions at 19 common insertion sites, including Zeb2, Nf1, Mn1, Evi1, Ift57, Mpl, Plag1, Kras, Erg, Vav1, and Gata1. A total of 26% (11 of 42) of the mice had retroviral integrations near Zeb2, a transcriptional corepressor leading to overexpression of the Zeb2-transcript. A total of 91% (10 of 11) of mice with Zeb2 insertions developed B-lineage acute lymphoblastic leukemia, suggesting that Zeb2 activation promotes the transformation of CALM-AF10 hematopoietic precursors toward B-lineage leukemias. More than half of the mice with Zeb2 integrations also had Nf1 integrations, suggesting cooperativity among CALM-AF10, Zeb2, and Ras pathway mutations. We searched for Nras, Kras, and Ptpn11 point mutations in the CALM-AF10 leukemic mice. Three mutations were identified, all of which occurred in mice with Zeb2 integrations, consistent with the hypothesis that Zeb2 and Ras pathway activation promotes B-lineage leukemic transformation in concert with CALM-AF10.
Caudell
David
D
Department of Biomedical Sciences and Pathobiology, Center for Molecular Medicine and Infectious Diseases, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA.
Harper
David P
DP
Novak
Rachel L
RL
Pierce
Rachel M
RM
Slape
Christopher
C
Wolff
Linda
L
Aplan
Peter D
PD
D000818:Animals; D015139:Blotting, Southern; D015153:Blotting, Western; D049109:Cell Proliferation; D018398:Homeodomain Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D016130:Immunophenotyping; D015448:Leukemia, B-Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D007942:Leukemia, Experimental / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008822:Mice, Transgenic; D016254:Mutagenesis, Insertional; D009154:Mutation / Q000235:genetics; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D012097:Repressor Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D012190:Retroviridae / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D000074165:Zinc Finger E-box Binding Homeobox 2; D018631:ras Proteins / Q000235:genetics
C114359:AF10-CALM fusion protein, human; D018398:Homeodomain Proteins; D015514:Oncogene Proteins, Fusion; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D012097:Repressor Proteins; C120602:ZEB2 protein, mouse; D000074165:Zinc Finger E-box Binding Homeobox 2; D018631:ras Proteins