bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activation Mechanisms of STAT5 by Oncogenic Flt3-ITD.
Authors: Choudhary Chunaram , Brandts Christian , Schwable Joachim , Tickenbrock Lara , Sargin Bulent , Ueker Andrea , Bohmer Frank D. , Berdel Wolfgang E. , Müller-Tidow Carsten , Serve Hubert 
Published: October 2019

Abstract
Mutations in the receptor tyrosine kinase Flt3 represent one of the most common known genetic lesions in AML. Internal tandem duplication (ITD) mutations clustered in the juxtamembrane domain are the most frequent and best characterized mutations found in Flt3. We and others have previously reported that oncogenic activation of Flt3 by ITD mutations activate aberrant signaling including activation of STAT5, up-regulation of STAT targets like-Pim and SOCS proteins and repression of the myeloid transcription factors Pu.1 and c/EBP-alpha (Mizuki et al., Blood96: 3907–14, 2000; Mizuki et al., Blood101: 3164–73, 2003). Earlier studies have observed activation of Src and Jak kinases by Flt3-ITD but the mechanisms of STAT5 activation by Flt3-ITD and the role of Src or Jak kinases in this process remains unclear. Using the specific small molecule inhibitors PP-1 and PP-2, we analyzed the role of Src kinases in Flt3-ITD mediated STAT5 activation. Treatment of Flt3-ITD expressing 32D cells with PP-1 and 2 had only marginal effect on Flt3-ITD induced STAT5 activation, which was due to a proportional inhibition of Flt3 kinase by these inhibitors. Similar results were obtained with AG490, reportedly a specific inhibitor of Jak2. However, use of cell a line deficient for all Src family kinases revealed a Src-independent activation of STAT5 by Flt3-ITD. Also, using cell lines deficient for Jak2 or Tyk2 we show that Flt3-ITD induced STAT5 activation independent of Jak2 or Tyk2 kinases. To rule out a possible redundant role of different Jak kinases in Flt3-ITD mediated STAT5 activation, we used SOCS1, a target of STAT5 and a potent molecular inhibitor of all Jak kinases. Surprisingly, retroviral transduction of 32D cells with SOCS1 inhibited IL-3 but not Flt3-ITD mediated proliferation of these cells. Similar results were obtained with SOCS3, another inhibitor of Jak kinases. Detailed signaling analyses of stable 32D cells co-expressing Flt3-ITD and SOCS1 revealed that activation of the STAT5 and up-regulation of STAT5 target gene Pim-2 by Flt3-ITD is completely resistant to SOCS1. In contrast, expression of SOCS1 severely inhibited IL-3 mediated STAT5 activation. Furthermore, using purified recombinant STAT5 and Flt3 kinase in in-vitro kinase assays, we show that STAT5 is indeed a direct target of Flt3. Taken together, our data show that Flt3-ITD directly activates STAT5 independent of Src or Jak kinases, providing the mechanistic basis of Flt3-ITD induced STAT5 activation. Furthermore, our finding that Flt3-ITD up-regulates SOCS proteins but activate STAT5 in a SOCS1 resistant manner may have important implications for Flt3-ITD-mediated modification of cytokine signaling.
Characterization of a Novel R-RAS Mutation Cloned from Primary AML Cells.
Authors: Reuter Christoph W.M. , Aydilek Erdem , Onono Fredrick O. , Morgan Michael A. , Henningfeld Kristine A. , Ganser Arnold 
Published: October 2019

Abstract
Mammalian RAS genes encode a family of small GTPases, which are involved in signal transduction pathways resulting in cell growth and differentiation. Many human cancers, including hematologic malignancies, have been found to harbor activating H-, K- and N-RAS mutations. We report here the discovery and characterization of a novel, activating R-RAS mutation cloned from primary AML cells. Total RNA was purified from AML blasts, reverse transcribed into cDNA and R-RAS-specific PCR products were sequenced on an ABI310 automated DNA sequencer. A mutation in codon 84 of R-RAS (Thr to Ala, T84A) was detected in a female AML patient with normal karyotype. The R-RAS T84A mutant was cloned into a hygromycin B-resistant pCGN vector and used to stably transfect BA/F3 cells, an IL-3-dependent murine pro B-cell line. The well-described R-RAS Q87L activating mutant was employed as a positive control for R-RAS-induced transformation of BA/F3 cells as well as for activation of signal transduction pathways. The R-RAS T84A mutant protected BA/F3 cells from the apoptotic effects of IL-3 starvation, albeit to a lesser extent than the R-RAS Q87L mutant. Interestingly, these two R-RAS mutants activate distinct signal transduction pathways. For example, the R-RAS Q87L mutant preferentially caused activation of the RAS-to-MAPK signal cascade as evidenced by Western blots of affinity precipitations with the GST-conjugated c-Raf-1 RAS binding domain, which is designed to bind GTP-loaded (activated) RAS proteins. The R-RAS T84A mutant activated the PI-3K pathway as demonstrated by Western blots of affinity precipitations with the GST-coupled RAS binding domain of the p110-alpha subunit of PI-3K. Additionally, the R-RAS T84A mutant induced a stronger phosphorylation of the PI-3K down-stream target Akt upon IL-3 stimulation (0.1 and 10 ng/mL, 10 minutes) of BA/F3 cells cultured overnight without IL-3. In conclusion, a novel R-RAS mutation was found in primary AML blasts and the mutant protein activates anti-apoptotic signaling through the PI-3K/Akt pathway.
Oncogenic CBL Mutants Have Transforming Potential in Cells Expressing the FLT3 Tyrosine Kinase.
Authors: Reindl Carola , Vempati Sridhar , Quentmeier Hilmar , Mellert Gudrun , Hiddemann Wolfgang , Spiekermann Karsten 
Published: October 2019

Abstract
CBL is a E3-ubiquitin ligase, that negatively regulates many receptor tyrosine kinases (RTKs). Translocations (t(4;11); t(11;14) involving CBL in humans and two oncogenic CBL deletion mutants, CBL-70Z and v-CBL, inducing B-cell lymphomas in mice, were described. The RTK Fms-like tyrosine kinase 3 (FLT3) is expressed by the leukemic cells of 70–90% of patients with acute myeloid leukemia (AML) and acute lymphoid leukemia (ALL) and is highly implicated in the malignant transformation by harbouring activating mutations, aberrant autocrine stimulation or overexpression.
We hypothesized that CBL could play a role in regulating FLT3 activity and if mutated, could cause aberrant FLT3 signaling in hematopoietic cells. To analyze if CBL mutants could lead to transformation of FLT3-expressing cells we stably transduced Ba/F3 cells with CBL-WT, CBL-70Z or v-CBL alone or together with FLT3-WT. Coexpression of FLT3-WT and a CBL mutant, CBL-70Z or v-CBL, but not CBL-WT or expression of a CBL-construct alone, conferred IL-3 independent growth to Ba/F3 cells. In presence of FLT3 ligand FLT3-WT/CBLmutant-expressing cells showed hyperproliferation. To determine whether the proliferative advantage of FLT3-WT/CBL-70Z and FLT3-WT/v-CBL cells is mediated by FLT3 we cultivated the cells in presence of selective FLT3 inhibitors, SU5614 and PKC412. Both inhibitors were able to abrogate the IL-3 independent and FL-stimulated growth of FLT3-WT/CBL-70Z and FLT3-WT/v-CBL cells. The FLT3-WT receptors and the downstream signaling pathway, STAT5, were constitutively active in FLT3-WT/CBLmutant-expressing cells in contrast to control cells. To clarify the mechanism of transformation we performed internalization assays. The rate and speed of internalization of the FLT3-WT receptors were not altered in FLT3-WT/CBL-70Z and FLT3-WT/v-CBL cells compared to FLT3-WT cells. However, we could show that CBL-WT promotes FLT3 degradation. To investigate if CBL mutations play a role in acute leukemias we screened the cDNA of 62 AML and 6 ALL cell lines and found a CBL deletion mutant in MOLM-13 and MOLM-14 cells lacking exon 8, which comprises parts of the linker and RING finger domain. Hence, this mutation targets the same functionally important regions of the CBL protein than the CBL-70Z deletion.
In summary, CBL-70Z and v-CBL, but not CBL-WT, confer a transforming potential to cells expressing FLT3. The pro-proliferative phenotype of FLT3-WT/CBL-70Z and FLT3-WT/v-CBL cells is mediated by an increase in FLT3 tyrosine kinase activity. The CBL-70Z and v-CBL mutations were hypothesized to act in a dominant negative manner abrogating the negativ-regulatory function of CBL-WT. We identified a CBL deletion mutant in the MOLM-13 and MOLM-14 cells, that is reminiscent of CBL-70Z, indicating that CBL mutations might play a role in the pathogenesis of acute leukemias.
Towards a Pediatric Approach in Adults with Acute Lymphoblastic Leukemia (ALL): The GRAALL-2003 Study.
Authors: Huguet Françoise , Raffoux Emmanuel , Thomas Xavier , Leguay Thibaut , Chevallier Patrice , Escoffre Martine , Reman Oumedaly , Caillot Denis , Vey Norbert , Boissel Nicolas , Hunault Mathilde , Buzyn Agnes , Chalandon Yves , Delannoy Andre , Vernant Jean-Paul , Lheritier Veronique , Bene Marie-Christine , Macintyre Elizabeth , Ifrah Norbert , Dombret Herve 
Published: October 2019

Abstract
Introduction: In a recent French FRALLE versus LALA comparison, we have demonstrated a large benefit in outcome when adolescents and young adults were treated in a pediatric rather than an adult ALL protocol (Boissel JCO 2003). Similar provocative results have been observed in three other pediatric versus adult ALL studies (Stock ASH 2000, de Bont Leukemia 2004, Testi ASH 2004). One explanation may be the larger amounts of steroids, vincristine (VCR), and L-asparaginase (L-aspa) administered in pediatric patients. The GRAALL-2003 study was thus designed to offer a pediatric approach in adults with Ph-negative ALL until 60 years of age.
Methods: Treatment included a 5-drug induction, high dose-intensity consolidation blocks, delayed intensification, and 2-year maintenance. The comparison with the former LALA-94 protocol showed a 8.6-fold, 3.7-fold, and 16-fold increase in cumulative doses of prednisone, VCR, and L-aspa, respectively. One difference with childhood ALL therapy remained indication of allogeneic SCT in first CR which was offered to all patients with high-risk factor and a donor. In addition, induction was reinforced with a hyper-cyclophosphamide sequence (HyperC) in case of poor early response (cortico- and/or chemoresistant ALL). In the present report, 212 GRAALL-2003 patients with Philadelphia-negative ALL aged 15–55 years with a median follow-up of 18 months were compared to 712 patients previously treated in the LALA-94 trial.
Results: Cohorts were comparable in terms of prognostic factors. CR rate was significantly higher in GRAALL patients (93 vs 88%, P=0.02) due to a reduction in resistant disease (0.5 vs 8%, P<0.001) with comparable induction death (6 vs 5%, P=0.37) rate. When compared to the LALA-94 study, 2-year EFS and overall survival were markedly improved (56 vs 41% and 66 vs 54%; P=0.0002 and 0.02, respectively). Similar differences were observed after censoring SCT patients at transplant time, underlining the role played by chemotherapy modification. Because of a worse tolerance to induction and post-remission therapy, the benefit associated with the GRAALL approach decreased with advanced age, becoming not statistically significant over 40 years of age. Finally, outcome improvement was higher in T- than in B-lineage ALL (2-year overall survival, 75 vs 51% and 61 vs 56%; P=0.016 and 0.25, respectively). Among patients with T-ALL, poor early responders (allocated to HyperC induction) tended to have a better EFS than good early responders, suggesting a major role of HyperC in this ALL subset.
Conclusion: In conclusion, a pediatric approach benefits to younger adults with ALL.
Gene Expression Patterns Identify Patients with Non-Small Cell Lung Cancer (NSCLC) and Ovarian Cancer Who Are at Increased Risk for Venous Thromboembolism (VTE).
Authors: Ramiah Veshana S. , Potti Anil , Peterson Rebecca , Harpole David , Berchuck Andrew , Ortel Thomas L. 
Published: October 2019

Abstract
Background: VTE is the leading cause of death in patients with cancer. The 1-year survival rate in patients diagnosed with cancer at time of VTE is 12% compared to 36% in cancer patients without thrombosis. Cancer patients who develop VTE have higher mortality during hospitalization and during surgery. VTE in cancer patients portends a poorer prognosis and may indicate a more aggressive phenotype. There are, as yet, no clinical or laboratory parameters that have clinical utility in identifying this important group of patients with cancer who are at risk for developing VTE.
Methods: We explored whether gene expression profiling could define phenotype-specific metagenes (aggregate patterns of gene expression) that distinguish cancer patients with and without VTE. The medical history of 95 patients with NSCLC and 37 patients with ovarian cancer was reviewed to identify patients with VTE after the initial diagnosis of cancer but not within 6 weeks of surgery. Separate sets of controls with NSCLC and ovarian cancer, respectively, were identified from the same groups, matched by age, gender and clinical stage, but without VTE for at least 2 years following the diagnosis of cancer. RNA was extracted and gene array data obtained using Affymetrix U133 GeneChips. Gene expression data was analyzed using binary regression methodologies.
Results: 13/95 (13.5%) patients with NSCLC and 6/37 (16%) with ovarian cancer had VTE and met inclusion criteria. Using the metagene approach, a discriminator gene set (n=50) that differentiated patients with NSCLC and VTE from patients with NSCLC without VTE was identified. A separate discriminator gene set was identified for the ovarian cancer group. A leave-one-out cross validation performed to validate the reliability of the discriminator metagene set was 85% accurate in identifying patients with NSCLC and VTE. Similar analysis for the ovarian cancer patients was limited by the small number of patients identified. Significant biological differences were seen between the comparison groups in the NSCLC subset, including genes such as P53, VEGFC, E2F4, TFPI and EPHB2. Expression differences in the ovarian subset similarly included P53, but also included genes not seen in the NSCLC group, such as H-ras, Tissue factor and Factor X.
Conclusions: Our data suggests that a genomic approach can identify patients with cancer at risk for VTE. In addition, these results also suggest that different tumor types might possess unique expression signatures associated with increased thrombotic risk.
Platelet PF-4 Is an Early Marker of Tumor Angiogenesis.
Authors: Klement Giannoula L. , Cervi David , Yip Tai-Tung , Folkman Judah , Italiano Joseph 
Published: October 2019

Abstract
Early tumor detection and treatment is one of the most important determinants of cancer survival. We reported previously, that a ‘platelet angiogenesis proteome’ can detect clinically occult tumors in mice. We now present evidence that changes in platelet content of platelet factor-4 (PF-4) can be a consistent predictor of tumor growth across a spectrum of cancers. The differentially expressed protein was initially identified as a ~8200Da band by SELDI-ToF analysis. The protein band was isolated and positively identified by peptide sequencing and anti-PF-4 SELDI MS as PF-4. The platelet-associated PF-4 appeared to be up-regulated in early growth of human liposarcoma, mammary adenocarcinoma, osteosarcoma and down-regulated in a RIP-Tag model of pancreatic islet cell carcinoma. A 120 day follow-up study of liposarcoma revealed ≥2-fold increases of platelet-associated PF-4 at 19, 30 and 120 days. Concomitantly, only a ~0.5–1 fold decrease in PF-4 in plasma was observed. There were minimal changes in the plasma of animals bearing other human tumor xenografts. We conclude that platelet-associated PF-4, but not its plasma counterpart, may be a promising marker of early tumor growth or tumor recurrence.
Nitric Oxide and Asymmetric Dimethlyarginine Levels in Malignancy Associated Thrombosis and Their Modulaiton by Anticoagulants.
Authors: Hoppensteadt Debra , Fareed Daniel , Iqbal Omer , Lale Ajit , Fareed Jawed 
Published: October 2019

Abstract
Nitric oxide (NO) represents one of the major endothelial derived vasoactive mediators. Asymmetric dimethylarginine (ADMA) is an endogenous competitive inhibitor of NO synthase which inhibits NO production at Pathophysiologic levels. While the association of ADMA in cardiovascular diseases is known, no information on the ADMA levels is available in cancer patients. To test the hypothesis that endothelial dysfunction in cancer patients may result in increased ADMA levels, plasma samples were analyzed from an open label, multidose, active comparator designed study in which all patients (n=110) were initially treated with low molecular weight heparin, enoxaparin (E) at 1–1.5 mg/kg sc for 5 days. These patients were further subdivided. One group continued to receive E whereas the other group received warfarin (W) for up to 12 weeks. Baseline blood samples (BL), 5 days post E (IPE) and 4–6 week samples from the E and W were analyzed for ADMA and NO levels (Cardiovasics, Palo Alto, CA; R&D Systems, Minneapolis, MN, respectively). In comparison to the aged matched controls both the ADMA and NO levels were markedly elevated in cancer patients. The E treated group showed a marked decrease in the ADMA levels which persisted throughout the treatment period. However in the W converted group the ADMA levels rebounded to an increased level indicating that E differentially regulated ADMA in these patients. The down regulation pattern of NO was similar for both enoxaparin and warfarin. These results suggest that patients with cancer and thrombosis exhibit simultaneous up regulation of ADMA and NO. While enoxaparin and warfarin show a differential regulation of ADMA both result in down regulation of NO. The fact that E regulates ADMA is highly suggestive of its regulatory role in iNOX which may be involved in the inflammatory response in cancer patients. Furthermore, these studies underscore the anti-inflammatory mechanisms by which low molecular weight heparins such as E, mediate their therapeutic effects in cancer asscoiated thrombosis.
Group Nitric Oxide (uM) ADMA (uM) Aged matched controls 18±5 1.51±0.52 BL 63±18 5.34±1.5 IPE 22±9 2.81±0.9 4–6 weeks enoxaparin 20±8 2.45±0.9 4–6 weeks warfarin 25±8 3.67±1.1
MicroRNA Signatures Associated with Cytogenetics and Outcome in Acute Myeloid Leukemia.
Authors: Garzon Ramiro , Volinia Stefano , Liu Chang G. , Pichiorri Flavia , Palumbo Tiziana , Fabbri Muller , Cimmino Amelia , Alder Hansjuerg , Flomenberg Neal , Coombes Kevin R. , Calin George A. , Andreeff Michael , Croce Carlo M. 
Published: October 2019

Abstract
MicroRNAs are small non-coding RNAs of 19–25 nucleotides in length that are negative regulators of gene expression. Findings over the last few years indicate that microRNAs are involved in fundamental cellular process, including development and hematopoietic differentiation. Acute myeloid leukemia (AML) is a heterogeneous disorder that is characterized by proliferation of immature cells. Although there are well defined molecular subtypes of AML, the pathogenesis in the majority of cases is largely unknown. Focusing on known genes will not likely suffice to uncover the nature of the AML. The integration of a whole genome approach including non-coding RNA gene products may lead to an improve understanding of the biology of AML.
Methods: To determine whether microRNAs are associated with known cytogenetic abnormalities and biological features in AML, we evaluated the microRNA expression profiles of 176 samples of adult AML with intermediate and poor risk cytogenetics and 10 CD34+ cells from healthy donors using a microarrays platform. After normalization, data were analyzed using significance analysis of microarrays and prediction analysis of microarrays software. An independent set of 28 patients with AML was used to validate the signatures using quantitative real time PCR. Treatment response was evaluated in 29 newly AML diagnosed patients 4 to 6 weeks after induction chemotherapy with idarubicin and cytarabine by bone marrow examination. Complete remission was defined as less than 5% blasts in the bone marrow. Otherwise it was categorized as resistant disease.
Results: We found several microRNAs differentially expressed between CD34+ cells and all the AML samples. A subset of these microRNAs reflects the differentiation stage of the leukemias and correlate with the French-American-British classification of AML. Likewise, microRNAs are closely associated with the prevalent cytogenetic abnormalities. A common signature including the over expressed miR-20; miR-17, miR-25 and miR-191 are associated with short overall survival, while miR-29b is found down-regulated in patients with resistant disease. Furthermore, we proved experimentally that miR-29b regulates negatively MCL-1, a critical apoptosis regulator, which has been found up-regulated and associated with relapse and chemotherapy resistance in leukemia.
Conclusions: MicroRNAs expression in AML is closely associated with differentiation stage, morphology and cytogenetics. A subset of MicroRNAs is correlated with survival and treatment response.
Requirement of Transferrin for Iron-Induced Hepcidin Expression in the Zebrafish.
Authors: Fraenkel Paula G. , Dooley Kim A. , Zon Leonard I. 
Published: October 2019

Abstract
The zebrafish mutant gavi was identified in a large-scale chemical mutagenesis screen for embryonic anemia. Two alleles were discovered: gaviHE067 and gaviIT029, both of which have a homozygous recessive pattern of inheritance. The gavi mutants developed severe hypochromic anemia at 48 hours post-fertilization and died by 14 days post-fertilization. To determine the cause of the hypochromic anemia, low resolution genetic mapping was performed which revealed transferrin as a candidate gene. Sequencing of transferrin cDNA from the mutants confirmed that each allele of gavi harbors a mutation that results in aberrant splicing, while quantitative realtime RT-PCR demonstrated virtually absent transferrin expression in the mutants. Our previous work demonstrated that expression of hepcidin, an iron regulatory gene, is upregulated 18 hours following iron dextran injection of the zebrafish embryo. This effect was not impaired by a defect in ferroportin1 (Fraenkelet al., (2005) J Clin Invest115:1532–1541), an iron exporter and ligand for hepcidin. To evaluate the effects of iron loading on transferrin-deficient mutants, gaviIT029 homozygotes at 48 hours post-fertilization were either anesthetized and injected with iron dextran, or anesthetized but not injected. Transferrin expression was assayed 18 hours post-treatment. gaviIT029 homozygote embryos exhibited low levels of hepcidin expression that failed to increase following iron injection. These findings provide the first evidence to support the hypothesis that transferrin is required for the induction of hepcidin expression in response to iron loading in vivo.