* Authors on the Steering Committee contributed equally to the oversight of the study, including study design and maintaining the quality of study conduct. CONTRIBUTORS Owen O'Connor, Barbara Pro, Tim Illidge and Lorenz Trumper formed the ECHELON-2 steering committee and contributed equally to the oversight of the study, including study design and maintaining the quality of study conduct.

The functional capacity of C5 variants with mutations at Arg885, together with their failure to undergo blockade by eculizumab, account for the poor response to this agent in patients who carry these mutations. (Funded by Alexion Pharmaceuticals and the Ministry of Health, Labor, and Welfare of Japan.).

Karyotypic abnormalities in cultured embryonic stem cells (ESCs), especially near-diploid aneuploidy, are potential obstacles to ESC use in regenerative medicine. Events causing chromosomal abnormalities in ESCs may be related to events in tumor cells causing chromosomal instability (CIN) in human disease. However, the underlying mechanisms are unknown. Using multiparametric permeabilized-cell flow cytometric analysis, we found that the mitotic-spindle checkpoint, which helps maintain chromosomal integrity during all cell divisions, functions in human and mouse ESCs, but does not initiate apoptosis as it does in somatic cells. This allows an unusual tolerance to polyploidy resulting from failed mitosis, which is common in rapidly proliferating cell populations and which is reduced to near-diploid aneuploidy, which is also common in human neoplastic disease. Checkpoint activation in ESC-derived early-differentiated cells results in robust apoptosis without polyploidy/aneuploidy similar to that in IntroductionAn important task facing living organisms from birth to death is maintenance of the genome and its transfer to offspring. Elaborate mechanisms have developed to detect, repair, and prevent transfer of genome damage. 1,2 Mechanisms such as DNA repair or apoptotic culling of damaged cells have been evolutionarily conserved from the simplest multicellular organisms. Genome maintenance is especially important in cells of developing mammalian embryos deriving from a single zygotic cell and in adult stem cells, such as hematopoietic stem cells. A particularly vulnerable time in the life of eutherian mammals is the time from fertilization through cleavage and blastocyst formation, prior to uterine implantation, where developing embryos must survive almost independent from maternal nurturing. A highly specialized program of cellular regulation operates during this time, especially in pluripotent embryonic stem cells (ESCs) derived from the blastocyst that give rise to all adult somatic tissues. [3][4][5][6][7][8][9][10][11] ESCs from several mammalian species, including humans, isolated and cultured in vitro as immortalized cell lines, 12,13 provide the potential for therapeutic use in humans. Understanding these specialized embryonic strategies of genome maintenance is necessary to ensure their safe and effective use and may also reveal clues for studies of potentially similar behavior in adult stem cells.Immortalized mouse (m) and human (h) ESCs are subject to genetic and epigenetic instability, primarily chromosomal aberrations such as loss of heterozygosity, uniparental disomy, and aneuploidy. [14][15][16][17][18][19][20][21] This increases the risk of tumorigenic potential and other complications if hESCs are to be used therapeutically. Such behavior is likely related to their specialized strategies for genome maintenance, such as truncated cell cycles with very short or absent gap phases and differences in certain cell-cycle checkpoints compared with somatic cells. 2-5 A problem with analyzing protein biochemi...

Many growth factors and cytokines prevent apoptosis. Using an expression cloning method, we identified a novel antiapoptotic molecule named Anamorsin, which does not show any homology to known apoptosis regulatory molecules such as Bcl-2 family, caspase family, or signal transduction molecules. The expression of Anamorsin was completely dependent on stimulation with growth factors such as interleukin 3, stem cell factor, and thrombopoietin in factor-dependent hematopoietic cell lines, and forced expression of Anamorsin conferred resistance to apoptosis caused by growth factor deprivation in vitro. Furthermore, Anamorsin was found to act as an antiapoptotic molecule in vivo because Anamorsin−/− mice die in late gestation due to defective definitive hematopoiesis in the fetal liver (FL). Although the number of hematopoietic stem/progenitor cells in the FL did not decrease in these mice, myeloid, and particularly erythroid colony formation in response to cytokines, was severely disrupted. Also, Anamorsin−/− erythroid cells initiated apoptosis during terminal maturation. As for the mechanism of Anamorsin-mediated cell survival, a microarray analysis revealed that the expression of Bcl-xL and Jak2 was severely impaired in the FL of Anamorsin−/− mice. Thus, Anamorsin is considered to be a necessary molecule for hematopoiesis that mediates antiapoptotic effects of various cytokines.

These findings suggest that discontinuation of second- or subsequent-line dasatinib after a sustained DMR of ≥ 1 year is feasible, especially for patients with no history of imatinib resistance. In addition, the natural killer cell count was associated with the TFR.

Introduction c-Kit is a receptor tyrosine kinase (RTK), which constitutes a type III RTK subfamily with the receptors for platelet-derived growth factor (PDGF), colony-stimulating factor 1 (CSF-1), and flt-3 ligand. 1,2 The type III RTKs are characterized by an extracellular domain with 5 immunoglobulinlike domains and a cytoplasmic domain consisting of a kinase domain that is interrupted by a kinase insert. c-Kit (KIT) and its ligand stem cell factor (SCF) play an important role in hematopoiesis, melanogenesis, and gametogenesis, 3 as has been clearly shown by loss of function mutations of c-kit gene. In addition, c-kit gene product has been associated with various forms of neoplasms. Activating mutants of KIT, either in the juxtamembrane domain or the catalytic domain, were identified as the cause for transformation of hematopoietic stem cells, mast cells, and gastrointestinal stromal cells. [4][5][6][7][8][9][10] Thus, KIT/SCF has pleiotropic functions such as proliferation, survival, differentiation, and transformation. In this report, we focus on SCF/KITmediated cell migration, which is also a characteristic function of SCF in hematopoietic stem cells and mast cells, [11][12][13] and has critical roles in immunity, metastasis, and development.On ligand stimulation, KIT receptors dimerize, activate its intrinsic tyrosine kinase, and autophosphorylate. The phosphorylated KIT receptor generates binding sites for SH2 domaincontaining proteins, which include proteins of the p21Ras-mitogenactivated protein kinase (MAPK) pathway, 14 the p85 subunit of phosphatidylinositol 3Ј kinase (PI3K), 15 phospholipase C-␥ 1 , the Grb2 adaptor protein, 16 the Src family kinases (SFKs), 17 Cbl, CRKL, 19 SHP1, and SHP2. 20 Those proteins are subsequently activated or phosphorylated and further transduce signaling cascades that lead to various cellular responses. However, little is known about which signaling is essential for SCF-mediated migration. Recently, a few reports indicated that Lyn or p38 MAPK plays an important role, 21,22 but no comprehensive investigation has been done in which the tyrosine residue of KIT is involved in signal transduction, which is required for cell migration. In this study, we have converted all possible tyrosine (Y) residues on KIT cytoplasmic domain to phenylalanine (F) and introduced these YF substitute mutants on 293T cells or murine interleukin 3 (IL-3)-dependent BAF3 cells. We used these cell lines to elucidate signaling cascades that are important for SCF-mediated cell Supported in part by grants from the Japanese Ministry of Education, Culture, Sports, Science and Technology, the Japanese Ministry of Health, Labor and Welfare, and the Japan Society for Promotion of Science.Reprints: Yuzuru Kanakura, Department of Hematology and Oncology, Osaka University Graduate School of Medicine, 2-2, Yamada-oka, Suita, Osaka 565-0871, Japan; e-mail: kanakura@bldon.med.osaka-u.ac.jp.The publication costs of this article were defrayed in part by page charge payment. Therefore, and solely to indicate thi...

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The online version of this article has a Supplementary Appendix. BackgroundPatients with acute myeloid leukemia who are treated with conventional chemotherapy still have a substantial risk of relapse; the prognostic factors and optimal treatments after relapse have not been fully established. We, therefore, retrospectively analyzed data from patients with acute myeloid leukemia who had achieved first complete remission to assess their prognosis after first relapse. Design and MethodsClinical data were collected from 70 institutions across the country on adult patients who were diagnosed with acute myeloid leukemia and who had achieved a first complete remission after one or two courses of induction chemotherapy. ResultsAmong the 1,535 patients who were treated with chemotherapy alone, 1,015 relapsed. Half of them subsequently achieved a second complete remission. The overall survival was 30% at 3 years after relapse. Multivariate analysis showed that achievement of second complete remission, salvage allogeneic hematopoietic cell transplantation, and a relapse-free interval of 1 year or longer were independent prognostic factors. The outcome after allogeneic transplantation in second complete remission was comparable to that after transplantation in first complete remission. Patients with acute myeloid leukemia and cytogenetic risk factors other than inv(16) or t(8;21) had a significantly worse outcome when they did not undergo salvage transplantation even when they achieved second complete remission. ConclusionsWe found that both the achievement of second complete remission and the application of salvage transplantation were crucial for improving the prognosis of patients with acute myeloid leukemia in first relapse. Our results indicate that the optimal treatment strategy after first relapse may differ according to the cytogenetic risk.Key words: acute myeloid leukemia, allogeneic hematopoietic cell transplantation, first relapse, second remission, cytogenetic risk. 2010;95(11):1857-1864. doi:10.3324/haematol.2010 This is an open-access paper. Citation: Kurosawa S, Yamaguchi T, Miyawaki S, Uchida N, Sakura T, Kanamori H, Usuki K, Yamashita T, Okoshi Y, Shibayama H, Nakamae H, Mawatari M, Hatanaka K, Sunami K, Shimoyama M, Fujishima N, Maeda Y, Miura I, Takaue Y, and Fukuda T. Prognostic factors and outcomes of adult patients with acute myeloid leukemia after first relapse. Haematologica Prognostic factors and outcomes of adult patients with acute myeloid leukemia after first relapse