bluuebunny/crossref_metadata_2025_split huggingface dataset:
Different antiapoptotic pathways between wild-type and mutated FLT3: insights into therapeutic targets in leukemia
Authors: Minami Yosuke , Yamamoto Kazuhito , Kiyoi Hitoshi , Ueda Ryuzo , Saito Hidehiko , Naoe Tomoki 
Published: July 2003

AbstractAn internal tandem duplication (ITD) of the juxtamembrane (JM) domain of FLT3 (FLT3/ITD) has been found in 20% of patients with acute myeloid leukemia (AML) and is correlated with leukocytosis and a poor prognosis. Here, we compared the antiapoptotic effects of wild-type FLT3 (WtFLT3) and FLT3/ITD in terms of the regulation of Bcl-2 family members. In a murine myeloid cell line, 32D, interleukin-3 (IL-3) deprivation induced apoptosis following the down-regulation of Bcl-XL and the dephosphorylation of Bad. However, the expression levels of Bcl-2, Bax, Bak, and Mcl-1 were unchanged. In WtFLT3-transfected 32D (WtFLT3-32D) cells, FLT3 ligand (FL) stimulation did not restore the down-regulation of Bcl-XL but maintained the phosphorylation of Bad. Combined treatment with phosphatidylinositol 3-kinase (PI3K) inhibitor, LY294002, and mitogen-activated protein kinase kinase (MEK) inhibitor, PD98059, dephosphorylated Bad and induced apoptosis in WtFLT3-32D cells stimulated with FL. Induction of nonphosphorylated Bad induced remarkable apoptosis. These findings suggest that the FL stimulation is associated with antiapoptosis through Bad phosphorylation. On the other hand, FLT3/ITD-transfected 32D (FLT3/ITD-32D) cells survived in an IL-3–or FL-deprived state. Furthermore, the dephosphorylation of Bad using LY294002 and PD98059 was insufficient for apoptosis, and the down-regulation of Bcl-XL using antisense treatment was needed to induce apoptosis. FLT3 kinase inhibitor, AG1296, alone not only dephosphorylated Bad but also down-regulated Bcl-XL, leading FLT3/ITD-32D cells into apoptosis. These findings suggest that the antiapoptotic pathways from FLT3/ITD are more divergent than those from WtFLT3 and may represent targets for drug discovery with the potential of inducing selective cell death of human leukemia cells.
Overexpression of the Notch ligand, Jagged-1, induces alloantigen-specific human regulatory T cells
Authors: Yvon Eric S. , Vigouroux Stephane , Rousseau Raphael F. , Biagi Ettore , Amrolia Persis , Dotti Gianpietro , Wagner Hans-Joachim , Brenner Malcolm K. 
Published: July 2003

AbstractGraft-versus-host disease (GVHD) represents one of the major complications of allogeneic hematopoietic stem cell transplantation. Techniques to prevent GVHD have included ex vivo T-cell depletion of the graft or prolonged in vivo immunosuppression. Both reduce the frequency and severity of GVHD but also reduce T-cell-mediated graft-versus-malignancy effect, and increase the risk of infection. A major goal in transplantation is to prevent alloreactivity while preserving activity against tumors and infectious agents. We have used activation of the Notch pathway to try to generate T cells able to specifically regulate alloantigen responses. We used allogeneic Epstein-Barr virus lymphoblastoid B cells (EBV-LCLs) as stimulator cells. Such LCLs are excellent (allo) antigen-presenting cells and can be obtained in large numbers even from donors who have received extensive chemo/radiotherapy. We overexpressed a Notch ligand, Jagged-1, in these cells by adenoviral vector transduction. Stimulation of CD45RA+ naive T cells by Jagged-1 EBV-LCL reduces production of interferon-γ, interleukin-2, and interleukin-5, but up-regulates transforming growth factor-β1 synthesis, consistent with induction of a regulatory T-cell phenotype. Transfer of these T cells to fresh lymphocyte cultures inhibits proliferative and cytotoxic immune responses to the priming alloantigens while sparing responses to third-party stimulator cells. Notch activation in the presence of alloantigen-presenting cells may therefore be a means of inducing specific regulatory T cells while preserving other T-cell functionality. (Blood. 2003;102:3815-3821)
IGF-1 down-regulates IFN-γR2 chain surface expression and desensitizes IFN-γ/STAT-1 signaling in human T lymphocytes
Authors: Bernabei Paola , Bosticardo Marita , Losana Giuliana , Regis Gabriella , Di Paola Francesca , De Angelis Stefania , Giovarelli Mirella , Novelli Francesco 
Published: July 2003

AbstractThe ability of insulin-like growth factor-1 (IGF-1) to regulate surface expression of the interferon-γ receptor 2 (IFN-γR2) transducing chain and activation of IFN-γ–induced signal transducer and activator of transcription-1 (STAT-1) in human T cells was analyzed. We show that, especially in the absence of serum (which contains IGF-1), IGF-1 down-regulated surface expression of the IFN-γR2 chain and inhibited both IFN-γ–dependent STAT-1 activation and apoptosis in T-cell lines ST4, Jurkat, and Molt-4. IFN-γR2 down-regulation resulted from its enhanced internalization since IGF-1 completely restored the uptake of anti–IFN-γR2 monoclonal antibody (mAb) in serum-deprived T-cell lines. When the interaction between IGF-1 and its receptor was blocked by anti–IGF-1R mAb, enhancement of IFN-γR2 surface expression, STAT-1 activation, and reinstatement of IFN-γ–induced apoptosis were observed. Enhanced expression of IFN-γR2 was also observed in phytohemagglutinin (PHA)–activated T lymphoblasts cultured in the presence of anti–IGF-1R mAb, whereas IGF-1 or anti–IGF-1R mAb did not modify the high IFN-γR2 expression in B and myeloid cell lines. Both IGF-1 and anti–IGF-1R mAb did not modify the constitutive expression of IFN-γR2 mRNA in T cells as well as the high IFN-γR1 binding chain surface expression in T, B, and myeloid cells. These data indicate that IGF-1 plays a critical role in the desensitization of IFN-γ/STAT-1 signaling in T lymphocytes by delivering a signal for IFN-γR2 internalization.
Vasculin, a novel vascular protein differentially expressed in human atherogenesis
Authors: Bijnens Ann P. J. J. , Gils Ann , Jutten Barry , Faber Birgit C. G. , Heeneman Sylvia , Kitslaar Peter J. E. H. M. , Tordoir Jan H. M. , de Vries Carlie J. M. , Kroon Abraham A. , Daemen Mat J. A. P. , Cleutjens Kitty B. J. M. 
Published: July 2003

Abstract
Recent suppressive subtractive hybridization analysis on human atherosclerotic plaque-derived RNA revealed genes upregulated in plaques with a thrombus versus stable plaques. Clone SSH6, containing part of a putative open reading frame of an unknown protein, was further investigated. Full-length cDNA, coding for a 473–amino acid (aa) protein, was identified in a vascular smooth muscle cell (SMC) cDNA library. Bioinformatics suggested the presence of multiple SSH6 variants due to alternative splicing of exon 3. Multiple-tissue Northern blot analysis demonstrated a differential expression pattern of these variants, as a ubiquitously expressed SSH6 mRNA missing exon 3, was detected apart from a putative vascular SMC–specific form containing exon 3. Western blot analysis indicated a ubiquitous 35-kDa protein (SSH6-β), in addition to a 45-kDa protein (vasculin), detected in the vascular wall and in plasma. Analysis of arteries displaying various stages of atherosclerosis indicated that the vasculin/SSH6-β ratio increases throughout atherogenesis. Immunohistochemical analysis demonstrated cytoplasmic expression of SSH6 gene products in macrophages, endothelial cells, and SMCs. In summary, we identified a novel mRNA/protein, vasculin, in the arterial wall and plasma. The regulated expression of vasculin in plaques suggests a role in atherogenesis. Moreover, its presence in plasma opens perspectives for vasculin as a marker for atherosclerosis.
The mutation Ser511Asn leads to N-glycosylation and increases the cleavage of high molecular weight kininogen in rats genetically susceptible to inflammation
Authors: Isordia-Salas Irma , Pixley Robin A. , Parekh Hemant , Kunapuli Satya P. , Li Fengling , Stadnicki Anthony , Lin Yingzhang , Sartor R. Balfour , Colman Robert W. 
Published: July 2003

AbstractCrohn disease is immunologically mediated and characterized by intestinal and systemic chronic inflammation. In a rat model, injection of peptidoglycan-polysaccharide complexes into the intestinal wall induced chronic inflammation in Lewis but neither Fischer nor Buffalo rats, indicating a differential genetic susceptibility. Proteolysis of plasma high molecular weight kininogen (HK) yielding bradykinin and cleaved HK (HKa) was faster in Lewis than in Fischer or Buffalo rat plasma. A single point mutation at nucleotide 1586 was found translating from Ser511 (Buffalo and Fisher) to Asn511 (Lewis). The latter defines an Asn-Xaa-Thr consensus sequence for N-glycosylation. We expressed these domains in Escherichia coli and found no differences in the rate of cleavage by purified kallikrein in the 3 strains in the absence of N-glycosylation. We then expressed these domains in Chinese hamster ovary (CHO) cells, which are capable of glycosylation, and found an increased rate of cleavage of Lewis HK. The Lewis mutation is associated with N-glycosylation as evidenced by a more rapid migration after treatment with N-glycosidase F. When CHO cells were cultured in the presence of tunicamycin, the kallikrein-induced cleavage rate of Lewis HK was not increased. This molecular alteration might be one contributing factor resulting in chronic inflammation in Lewis rats.
Effect of farnesyl transferase inhibitor R115777 on the growth of fresh and cloned myeloma cells in vitro
Authors: Ochiai Naoya , Uchida Ryo , Fuchida Shin-ichi , Okano Akira , Okamoto Masashi , Ashihara Eishi , Inaba Tohru , Fujita Naohisa , Matsubara Hiroaki , Shimazaki Chihiro 
Published: July 2003

AbstractRas gene mutations occur in 30% to 40% of patients with multiple myeloma (MM), and farnesylation is the first and most important step in the posttranslational modification of Ras proteins. R115777 is a newly synthesized potent farnesyl transferase inhibitor (FTI) and has recently demonstrated significant antitumor activities in vitro and in vivo. Therefore, we examined the effect of R115777 on the growth of fresh and cloned myeloma cells in vitro. R115777 inhibited the growth of fresh and cloned myeloma cells dose dependently, and effects were not dependent on the status of N-Ras mutation in fresh myeloma cells. Flow cytometric analysis using annexin V and 7-aminoactinomycin D (7AAD) showed that R115777 induced apoptosis of 2 of 3 myeloma cell lines at a concentration of 1.0 × 10-8 M. R115777 appears to be a potent inducer of apoptosis, and its effects depend on the status of Ras mutation in cloned myeloma cells but not on the status of N-Ras mutation in fresh myeloma cells. This is the first report that demonstrates the relationship between the N-Ras mutation in fresh myeloma cells and the effect of R115777. R115777 might have some benefit in the treatment of myeloma patients.
Reduced-intensity conditioning for unrelated donor hematopoietic stem cell transplantation as treatment for myeloid malignancies in patients older than 55 years
Authors: Wong Raymond , Giralt Sergio A. , Martin Thomas , Couriel Daniel R. , Anagnostopoulos Athanasios , Hosing Chitra , Andersson Borje S. , Cano Pedro , Shahjahan Munir , Ippoliti Cindy , Estey Elihu H. , McMannis John , Gajewski James L. , Champlin Richard E. , de Lima Marcos 
Published: July 2003

Abstract
Hematopoietic stem cell transplantation from unrelated donors is an effective treatment for myeloid malignancies, but its use is usually restricted to young patients without comorbidities. The development of reduced-intensity preparative regimens has allowed the extension of this form of treatment to older and medically infirm patients. We assessed the outcomes of patients older than 54 years who received unrelated donor transplants for the treatment of myeloid malignancies in our institution. There were 29 patients (median age, 59 years) with advanced acute myeloid leukemia (n = 13), myelodysplastic syndrome (n = 7), and chronic myeloid leukemia (n = 9) included. With a median follow-up of 27 months, the probability of overall and event-free survival, and nonrelapse mortality at one year were 44%, 37%, and 55%, respectively. Grades II to IV acute graft-versus-host disease (GVHD) occurred in 41% of patients and chronic GVHD developed in 63% of patients surviving more than 100 days. Of the 11 survivors, 9 were interviewed and reported good quality of life after transplantation using the Functional Assessment of Cancer Therapy–Bone Marrow Transplant Scale (FACT-BMT) questionnaire, with high scores in all dimensions. Unrelated donor transplantation is a treatment option for older patients with myeloid malignancies. The results in this cohort of patients are comparable with those reported in younger patients with similarly advanced disease.
New score predicting for prognosis in PML-RARA+, AML1-ETO+, or CBFBMYH11+ acute myeloid leukemia based on quantification of fusion transcripts
Authors: Schnittger Susanne , Weisser Martin , Schoch Claudia , Hiddemann Wolfgang , Haferlach Torsten , Kern Wolfgang 
Published: July 2003

AbstractTo evaluate the prognostic significance of quantitative PML-RARA, AML1-ETO, and CBFB-MYH11 fusion transcript expression, real-time polymerase chain reaction was used to analyze bone marrow samples of 349 such patients at diagnosis and 522 samples of 142 patients also during therapy (total analyses, n = 859; median number of follow-up samples, 4/patient; median duration of assessment, 12 months). Lower expression levels at diagnosis correlated with better overall and event-free survival in all 3 leukemia subtypes. By combining the median expression ratio after consolidation therapy and the 75th percentile of the expression ratio at diagnosis, a new score was established that separates a group with 100% EFS from a significantly worse group (P &lt; .0001) in each of the 3 acute myeloid leukemia subgroups. Eight patients showed increasing levels of expression during follow-up and all had relapse. In conclusion, patients at high risk for treatment failure can be identified by high levels of fusion gene expression at diagnosis or less than 3 logs of tumor reduction during the first 3 to 4 months of therapy. By combining the transcription ratios at these 2 checkpoints, a new powerful prognostic score has been established.
Bone marrow precursor of extranodal T-cell lymphoma
Authors: Gniadecki Robert , Lukowsky Ansgar , Rossen Kristian , Madsen Hans O. , Thomsen Kristian , Wulf Hans Christian 
Published: July 2003

AbstractThe development of extranodal lymphomas is thought to be initiated by the transformation event in peripheral organs. Lymphomatoid papulosis (LyP) is a low-grade cutaneous lymphoma and may progress into the cutaneous anaplastic lymphoma. We identified 2 patients who 3 and 4 years before the development of LyP were treated for an unrelated malignancy (Burkitt lymphoma and small-cell B-cell lymphoma). We analyzed the T-cell receptor (TCR) gene rearrangement pattern in their skin, blood, and bone marrow, including the archival bone marrow sampled years before the development of clinically evident LyP. In all samples we detected the unique monoclonal TCR rearrangements. This observation suggests that the initial malignant transformation in LyP occurred in bone marrow and not, as could be supposed, in the skin. (Blood. 2003;102:3797-3799)
Tec regulates platelet activation by GPVI in the absence of Btk
Authors: Atkinson Ben T. , Ellmeier Wilfried , Watson Steve P. 
Published: July 2003

AbstractThe Tec family kinase Btk plays an important role in the regulation of phospholipase Cγ2 (PLCγ2) downstream of the collagen receptor glycoprotein VI (GPVI) in human platelets. Platelets also express a second member of this family, Tec; however, its function has not been analyzed. To address the role of Tec, we analyzed Btk-/-, Tec-/-, and Btk/Tec double-deficient (Btk-/-/Tec-/-) platelets. Tec-/- platelets exhibit a minor reduction in aggregation to threshold concentrations of collagen or the GPVI-specific agonist collagen-related peptide (CRP), whereas responses to higher concentrations are normal. Tyrosine phosphorylation of PLCγ2 by collagen and CRP is not altered in Tec-/- platelets. However, Btk-/-/Tec-/- platelets exhibit a greater reduction in PLCγ2 phosphorylation than is seen in the absence of Btk, thus revealing an important role for Tec in this situation. Furthermore, Btk-/-/Tec-/- platelets fail to undergo an increase in Ca2+, aggregation, secretion, and spreading in response to collagen or CRP, whereas they aggregate normally to adenosine diphosphate (ADP) and spread on fibrinogen. A residual GPVI signal exists in the Btk-/-/Tec-/- platelets as CRP synergizes with ADP to mediate aggregation. These results demonstrate an essential requirement for Tec and Btk in platelet activation by GPVI and reveal a functional role for Tec in the regulation of PLCγ2 in the absence of Btk. (Blood. 2003;102: 3592-3599)
Minimal residual disease–based role of imatinib as a first-line interim therapy prior to allogeneic stem cell transplantation in Philadelphia chromosome–positive acute lymphoblastic leukemia
Authors: Lee Seok , Kim Dong-Wook , Kim Yoo-Jin , Chung Nak-Gyun , Kim Yoo-Li , Hwang Ji-Yeon , Kim Chun-Choo 
Published: July 2003

Abstract
Fourteen adults with Philadelphia chromosome–positive acute lymphoblastic leukemia (Ph+ ALL) were studied to evaluate the role of imatinib prior to allogeneic stem cell transplantation (SCT). Of these, 12 patients were in complete hematologic response (CHR), and 2 were refractory. Imatinib was administered as an interim schedule after each chemotherapy course. After the first imatinib cycle, 11 patients remained in sustained CHR with a decrease in the BCR-ABL/ABL ratios (0.89 logs), and one refractory patient achieved CHR. Meanwhile, 2 patients were resistant to imatinib. Ten patients receiving a second imatinib cycle following consolidation showed sustained CHR, including 2 molecular CR, with a further decrease in the BCR-ABL/ABL ratios (0.19 logs). Twelve patients underwent SCT in a favorable status, and of these, 11 are still alive in a leukemia-free status at 9 to 28+ months after SCT. First-line imatinib interim therapy appears to be a useful strategy to bridge the time to SCT for patients with Ph+ ALL.
TGF-β signaling–deficient hematopoietic stem cells have normal self-renewal and regenerative ability in vivo despite increased proliferative capacity in vitro
Authors: Larsson Jonas , Blank Ulrika , Helgadottir Hildur , Björnsson Jon Mar , Ehinger Mats , Goumans Marie-José , Fan Xiaolong , Levéen Per , Karlsson Stefan 
Published: July 2003

AbstractStudies in vitro implicate transforming growth factor β (TGF-β) as a key regulator of hematopoiesis with potent inhibitory effects on progenitor and stem cell proliferation. In vivo studies have been hampered by early lethality of knock-out mice for TGF-β isoforms and the receptors. To directly assess the role of TGF-β signaling for hematopoiesis and hematopoietic stem cell (HSC) function in vivo, we generated a conditional knock-out model in which a disruption of the TGF-β type I receptor (TβRI) gene was induced in adult mice. HSCs from induced mice showed increased proliferation recruitment when cultured as single cells under low stimulatory conditions in vitro, consistent with an inhibitory role of TGF-β in HSC proliferation. However, induced TβRI null mice show normal in vivo hematopoiesis with normal numbers and differentiation ability of hematopoietic progenitor cells. Furthermore HSCs from TβRI null mice exhibit a normal cell cycle distribution and do not differ in their ability long term to repopulate primary and secondary recipient mice following bone marrow transplantation. These findings challenge the classical view that TGF-β is an essential negative regulator of hematopoietic stem cells under physiologic conditions in vivo.
VH mutation status and VDJ rearrangement structure in mantle cell lymphoma: correlation with genomic aberrations, clinical characteristics, and outcome
Authors: Kienle Dirk , Kröber Alexander , Katzenberger Tiemo , Ott German , Leupolt Elke , Barth Thomas F. E. , Möller Peter , Benner Axel , Habermann Annett , Müller-Hermelink Hans Konrad , Bentz Martin , Lichter Peter , Döhner Hartmut , Stilgenbauer Stephan 
Published: July 2003

AbstractImmunoglobulin variable heavy chain gene (VH) mutation status and VDJ rearrangement structure were analyzed in 141 patients with mantle cell lymphoma (MCL) and correlated with biologic and clinical characteristics; 29% of the MCLs displayed mutated VH using a 98% germline homology cutoff. Striking differences occurred in the VH mutation subgroups with respect to the use of specific V genes. Rearrangements involving V4-34 and V3-21 were almost exclusively unmutated, whereas rearrangements using V4-59 and V3-23 were typically mutated. Significant association occurred between mutated VH with shorter CDR3 lengths and the use of JH4b. V3-21 and V4-59 were involved in highly characteristic rearrangements, implying that antigen specificity might have been involved in MCL development. There was no evidence for isotype switch recombination or Bcl-6 expression in any MCL. ZAP70 expression was not different in VH-mutated or -unmutated MCL. Although the deletions 11q– and 17p– showed a balanced distribution, an overrepresentation was observed for trisomies +3q, +8q, and tetraploidy in the VH-unmutated subgroup and +12q in the VH-mutated subgroup. Clinically, mutated VH was associated with a higher rate of complete remission, but there was no correlation between VH mutation status and other clinical characteristics or overall survival.
Active amino acids of the Kell blood group protein and model of the ectodomain based on the structure of neutral endopeptidase 24.11
Authors: Lee Soohee , Debnath Asim K. , Redman Colvin M. 
Published: July 2003

AbstractIn addition to its importance in transfusion, Kell protein is a member of the M13 family of zinc endopeptidases and functions as an endothelin-3–converting enzyme. To obtain information on the structure of Kell protein we built a model based on the crystal structure of the ectodomain of neutral endopeptidase 24.11 (NEP). Similar to NEP, the Kell protein has 2 globular domains consisting mostly of α-helical segments. The domain situated closest to the membrane contains both the N- and C-terminal sequences and the enzyme-active site. The outer domain contains all of the amino acids whose substitutions lead to different Kell blood group phenotypes. In the model, the zinc peptidase inhibitor, phosphoramidon, was docked in the active site. Site-directed mutagenesis of amino acids in the active site was performed and the enzymatic activities of expressed mutant Kell proteins analyzed and compared with NEP. Our studies indicate that Kell and NEP use the same homologous amino acids in the coordination of zinc and in peptide hydrolysis. However, Kell uses different amino acids than NEP in substrate binding and appears to have more flexibility in the composition of amino acids allowed in the active site.