Acute myeloid leukemia in clinical practice: a retrospective population-based cohort study in Miyazaki Prefecture, Japan.

We performed a retrospective population-based cohort study of acute myeloid leukemia (AML) in Miyazaki Prefecture, Japan. Over 6 years, we diagnosed 221 patients (211 adults and 10 children) with AML, indicating an incidence of AML in Miyazaki Prefecture of 3.2 per 100,000 per year.

R723, a selective JAK2 inhibitor, effectively treats JAK2V617F-induced murine myeloproliferative neoplasm.

The activating mutations in JAK2 (including JAK2V617F) that have been described in patients with myeloproliferative neoplasms (MPNs) are linked directly to MPN pathogenesis. We developed R723, an orally bioavailable small molecule that inhibits JAK2 activity in vitro by 50% at a concentration of 2nM, while having minimal effects on JAK3, TYK2, and JAK1 activity. R723 inhibited cytokine-independent CFU-E growth and constitutive activation of STAT5 in primary hematopoietic cells expressing JAK2V617F.

Tyrosine kinase 2 interacts with the proapoptotic protein Siva-1 and augments its apoptotic functions.

Siva-1 is a molecule that has the potential to induce both extrinsic (receptor-mediated) and intrinsic (non-receptor-mediated) apoptosis. Siva-1 binds to CD27, a member of the tumor necrosis factor receptor (TNFR) family, Abl-related gene (ARG), and BCL-X(L), and these partner molecules reportedly enhance the apoptotic properties of Siva-1. In this study, we show that Siva-1 also interacts with a member of the Jak family protein kinases, tyrosine kinase 2 (Tyk2).

JAK2 V617F uses distinct signalling pathways to induce cell proliferation and neutrophil activation.

The acquired JAK2 V617F mutation is observed in the majority of patients with BCR-ABL1 negative chronic myeloproliferative neoplasms (MPN). BCR-ABL1 negative MPN displays myeloproliferation with an elevated leucocyte alkaline phosphatase (LAP) activity, a neutrophil activation marker. We tried to separate the downstream signalling of JAK2 V617F to stimulate myeloproliferation and LAP activity.

Chronic thrombopoietin overexpression induces mesangioproliferative glomerulopathy in mice.

We previously reported that mice transgenic (Tg) for thrombopoietin (TPO) developed progressive fibrosis and osteosclerosis of the bone marrow. Here, we show that TPO-overexpressing mice also exhibited notable histological changes in the kidneys, including an increased number of mesangial cells, expansion of the mesangial matrix in the glomerulus, and atrophy of the renal tubuli. Plasma transforming growth factor (TGF)-beta1 and platelet-derived growth factor (PDGF)-BB, which could induce mesangioproliferative responses in glomeruli, were both elevated in TPO Tg mice, even though TPO itself has no effect on mesangial cells due to their lack of c-Mpl.