A novel fusion of RBM6 to CSF1R in acute megakaryoblastic leukemia.
Activated tyrosine kinases have been frequently implicated in the pathogenesis of cancer, including acute myeloid leukemia (AML), and are validated targets for therapeutic intervention with small-molecule kinase inhibitors. To identify novel activated tyrosine kinases in AML, we used a discovery platform consisting of immunoaffinity profiling coupled to mass spectrometry that identifies large numbers of tyrosine-phosphorylated proteins, including active kinases. This method revealed the presence of an activated colony-stimulating factor 1 receptor (CSF1R) kinase in the acute megakaryoblastic leukemia (AMKL) cell line MKPL-1. Further studies using siRNA and a small-molecule inhibitor showed that CSF1R is essential for the growth and survival of MKPL-1 cells. DNA sequence analysis of cDNA generated by 5'RACE from CSF1R coding sequences identified a novel fusion of the RNA binding motif 6 (RBM6) gene to CSF1R gene generated presumably by a t(3;5)(p21;q33) translocation. Expression of the RBM6-CSF1R fusion protein conferred interleukin-3 (IL-3)-independent growth in BaF3 cells, and induces a myeloid proliferative disease (MPD) with features of megakaryoblastic leukemia in a murine transplant model. These findings identify a novel potential therapeutic target in leukemogenesis, and demonstrate the utility of phosphoproteomic strategies for discovery of tyrosine kinase alleles.
Gu
Ting-lei
TL
Cell Signaling Technology, Danvers, MA 01923, USA.
Mercher
Thomas
T
Tyner
Jeffrey W
JW
Goss
Valerie L
VL
Walters
Denise K
DK
Cornejo
Melanie G
MG
Reeves
Cynthia
C
Popova
Lana
L
Lee
Kimberly
K
Heinrich
Michael C
MC
Rush
John
J
Daibata
Masanori
M
Miyoshi
Isao
I
Gilliland
D Gary
DG
Druker
Brian J
BJ
Polakiewicz
Roberto D
RD
D000818:Animals; D002460:Cell Line; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D002893:Chromosomes, Human, Pair 3; D002895:Chromosomes, Human, Pair 5; D006801:Humans; D007947:Leukemia, Megakaryoblastic, Acute / Q000209:etiology / Q000235:genetics*; D051379:Mice; D009368:Neoplasm Transplantation; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000302:isolation & purification; D016601:RNA-Binding Proteins / Q000235:genetics*; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D014178:Translocation, Genetic; D014183:Transplantation, Heterologous
D015514:Oncogene Proteins, Fusion; C120511:RBM6 protein, human; D016601:RNA-Binding Proteins; D011505:Protein-Tyrosine Kinases; D016186:Receptor, Macrophage Colony-Stimulating Factor