The polycythemia vera-associated Jak2 V617F mutant induces tumorigenesis in nude mice

STAT5 Activation Is Critical for the Transformation Mediated by Myeloproliferative Disorder-associated JAK2 V617F Mutant

“…We also observed that JAK2 V617F mutant induced cytokine-independent survival of JAK2-deficient erythroid progenitor cells (22). Moreover, tumorigenesis was induced after injection of Ba/F3 cells expressing JAK2 V617F mutant in nude mice, suggesting that JAK2 harboring the V617F mutation is a potent oncogene able to promote cell transformation and tumorigenesis (23). Interestingly, the transforming ability of JAK2 V617F mutant requires the expression of EpoR, suggesting that EpoR acts as a platform for JAK2 to exhibit proliferative signaling activity, as reported previously (24).…”

“…Cells were then centrifuged at 5,000 rpm for 2 min and resuspended in PBS containing 10 g/ml RNase A (Wako, Tokyo, Japan) and 100 g/ml propidium iodide (PI) (Sigma). Following a 30-min incubation, cell cycle parameters were determined by flow cytometry analysis using FACSCalibur (23). All data were recorded and analyzed using CellQuest software.…”

Antagonistic activities of the immunomodulator and PP2A-activating drug FTY720 (Fingolimod, Gilenya) in Jak2-driven hematologic malignancies

“…2,3 To evaluate the potential of using PADs and, specifically, FTY720 in Jak2 V617F MPN patients, we used an aggressive mouse model of Jak2 V617F leukemia in which each transplanted cytokine-independent Ba/F3-Jak2 V617F cell represents a potential leukemia-initiating cell. 30 SCID mice (n 5 30) were IV injected with Ba/F3-Jak2 V617F cells (5 3 10 5 cells/mouse). After 7 days, all mice were engrafted (presence in PB of GFP 1 Jak2 V617F cells) and FTY720 was intraperitoneally administered (10 mg/kg/d; LD 50 5 300 mg/kg) to 15 mice.…”

Three Tyrosine Residues in the Erythropoietin Receptor Are Essential for Janus Kinase 2 V617F Mutant-induced Tumorigenesis

“…Several studies have reported the importance of homodimeric cytokine receptors such as EpoR for the activation of the JAK2 V617F mutant and its cellular transforming activity (23)(24)(25)(26). The FERM domain of JAK2 is conserved in the JAK family and is necessary for the interaction of JAK2 with cytokine receptors (32,33).…”

“…To select infected JAK2-deficient MEFs, 2 g/ml puromycin and 200 g/ml hygromycin were used. Ba/F3 cells were infected with an empty virus (Ϫ) and retroviruses expressing wild-type JAK2 c-HA, JAK2 V617F mutant c-HA, wild-type EpoR c-FLAG, and EpoR mutant c-FLAG using RetroNectin (TAKARA, Shiga, Japan) as described previously (25). These cells were cultured in RPMI 1640 medium (Nacalai Tesque) supplemented with 10% FBS, 1% penicillin/ streptomycin mixed solution, and 2 ng/ml IL-3.…”