bluuebunny/crossref_metadata_2025_split huggingface dataset:
FLT3 Is Up-Regulated in Blast Crisis of Chronic Myeloid Leukemia and Combination of Small Interference RNA of FLT3 and Gleevec (STI571) Synergistically Induces the Apoptosis in K562 Cells.
Authors: Lee Young Y. , Ahn Kwang-Sung , Yoon Sung-Soo , Choi Jung H. , Park Byoung B. , Kim Byoung K. 
Published: October 2019

Abstract
To identify a gene signature for prognostic markers at transition from chronic phase to blast crisis of chronic myeloid leukemia (CML), we have applied Affymetrix Genechips of 22,000 transcripts to analyze total RNA of CML cells from 12 patients with chronic phase and 12 patients with blast crisis. Data analysis using GeneSpring 6.0 generated a list of 143 differentially expressed genes. A total of 89 genes were up-regulated and 54 genes were down-regulated in blast crisis of CML, and vice versa in chronic phase of CML. Array data for 32 genes was validated using quantitative realtime PCR analysis. The expression levels of HSA6591, FLT3, NTE5, RSG1, LAF4, CPA3, ATF, FCGR3A, MYD88, IFIT1, TP73L, DTNA, MDA, and IL18R1 showed statistically significant difference (p < 0.05) between chronic phase and blast crisis. Since CML cells of blast crisis were generally unresponsive to STI571, we further analyzed roles of FLT3 which is known to be a poor prognositic marker in acute myeloid leukemia. For this experiment, K562 cells (CML blast cells) were transfected with small hairpin RNAs (shRNAs), also referred to as small interfering RNAs, to target human FLT3, resulting in the significant inhibition of FLT3 expression at mRNA and protein levels. MTT assay demonstrated that FLT3 knockdown K562 cells by shRNAs were more sensitive to STI571 compared to wild type of K562, although there was no difference at high concentration of STI571 (320 nM) between FLT3 knockdown K562 cells and wild type of K562 cells. The higher expression levels of apoptosis related genes (PARP, caspase-3, Bax) were observed in FLT3 knockdown K562 cells compared to wild type of K562 cells. Thus, RNA interference-directed targeting of FLT3 might be a novel treatment modality in STI571 refractory CML patients.
Allogeneic Hematopoietic Stem Cell Transplantation for Patients with Chronic Myeloid Leukemia in Second Chronic Phase Attained by Imatinib after Onset of Blast Crisis.
Authors: Wang Ying , Wu De Pei , Sun Aing-Ning , Jin Zheng-ming , Miao Miao 
Published: October 2019

Abstract
The prognosis for patients with chronic myeloid leukemia (CML) in blast crisis (BC) remains dismal even with the availability of the BCR-ABL tyrosine kinase inhibitor imatinib, since it only offers short-term benefit in most cases. Allogeneic hematopoietic stem cell transplantation (HSCT) seems to be a viable option for BC-CML patients who attained remission. We treated 10 patients (9 males, 1 female) with ablative allogeneic HSCT, who achieved second chronic phase (CP) by the use of imatinib after onset of BC between October 2003 and August 2006. Median patient age was 32 years (range, 17–46). Imatinib was given orally at daily doses ranging from 600 to 800mg according to patients tolerance for at least 2 months (range, 2–5) prior to HSCT Among them, 4 patients received HSCT from human leukocyte antigen mismatched haplo-identical family donors, the others underwent a transplant from HLA matched related (n=5) or unrelated (n=1) donors. At the time of transplantation, 5 patients were in complete hematologic response with 3 patients achieved a cytogenetic response, 5 patients were in partial hematologic response. After a median follow-up of 26 months (range, 10–44), 6 (60%) out of the 10 patients were alive with mean Karnofsky score reaching 80. Among them, 5 patients achieved a molecular remission. 1 patient died in relapse 4 months after transplantation, the others died of severe acute graft-versus-host disease and associated infections. No unusual organ toxicities and engraftment difficulties were observed. Extensive chronic GVHD developed in 3 of 6 patients who could be evaluated. Patients transplanted with haplo-identical donors had a high treatment-related modality, 3 out of 4 patients died. These results suggest that allogeneic HSCT may represent a feasible treatment for patients with CML in second CP attained by imatinib after onset of BC especially when a suitable donor is available.
PHA-680626 Exhibits Anti-Proliferative and Pro-Apoptotic Activity on Imatinib-Resistant Chronic Myeloid Leukemia Cell Lines and Primary CD34+ Cells by Inhibition of Both Bcr-Abl Tyrosine Kinase and Aurora Kinases.
Authors: Gontarewicz Artur , Balabanov Stefan , Keller Gunhild , Panse Jens , Bernhardt Mirja , Bokemeyer Carsten , Fiedler Walter , Moll Jurgen , Brummendorf Tim 
Published: October 2019

Abstract
Emergence of resistance to Imatinib complicates the treatment of chronic myeloid leukemia (CML). Second-generation Bcr-Abl inhibitors are capable to overcome resistance mediated by most mutations except T315I. As this mutation is causative for ∼20% of clinically observed resistances, the need for novel treatment strategies becomes obvious. Here, we report on a novel kinase inhibitor PHA-680626 exhibiting strong inhibitory activity on both Bcr-Abl and Aurora kinases. Significant anti-proliferative and pro-apoptotic effects were observed in human BCR-ABL positive cell lines and murine BaF3 cells ectopically expressing wt BCR-ABL or the Imatinib resistant BCR-ABL mutants M351T, E255K and T315I. Treatment with PHA-680626 decreased phosphorylation of CrkL and histone H3. As CrkL represents a typical down-stream target of Bcr-Abl while histone H3 phosphorylation is an indicator for Aurora kinase B activity, these findings indicate that effects of PHA-680626 are mediated via inhibition of both pathways. Moreover, high antiproliferative activity of PHA-680626 was observed in primary CD34+ cells derived from CML patients at diagnosis or in blast crisis as well as from an individual harbouring the T315I mutation. Thus, both Bcr-Abl and Aurora kinase inhibition contribute to the efficacy of PHA-680626 against Imatinib-resistant BCR-ABL positive leukemias, particularly those harbouring the T315I mutation.
RARS-T without Thrombocytosis?.
Authors: Ravoet Christophe , Azerad Marie-Agnès , Delrieux Vanessa , Meuleman Nathalie , Bron Dominique 
Published: October 2019

Abstract
Background: Recently, a provisional entity called “refractory anemia with ringed sideroblasts with thrombocytosis” (RARS-T) has been characterized in the MDS/MPD overlap category of the WHO classification. Diagnostic criteria include RARS features in association with sustained platelet counts > 600 (500) x 109/l and exclusion of cytogenetic abnormalities such as 5q−, t(3,3) and inv(3). Reticulin fibrosis in the bone marrow has been significantly associated with RARS-T. Splenomegaly also seems more frequent than in other RARS subtypes. Among these patients, approximately two thirds present with a JAK2 V617F mutation. On the contrary, JAK2 V617F mutation appears extremely rare in patients with typical RARS (Szpurka H. Blood 2006, Cabello AI. Leuk Research 2005, Malcovati L. ASH 2006, Remacha AF. Haematologica 2006).
Case report: In 2001, we observed a 67 years old patient with RARS (22 to 45% ringed sideroblasts). Conventional cytogenetics revealed a trisomy 8 and deletion of chromosome Y. A mild to moderate fibrosis was observed in the bone marrow. At diagnosis, the patient was anaemic but had normal platelet counts which remained strictly normal during the next 6 years. After failure of various treatments, the transfusion requirements increased due to progressive alloimmunization and probably a moderate splenomegaly which had appeared 3 years after the diagnosis (splenic volume evaluated by ultrasonography was completely normal until 2004). In July 2006, the haemoglobin level was 6.1 g/dl despite the transfusion of 11 RBC units in the previous month. In the aim to overcome the suspected hypersplenism, a splenectomy was performed. In the subsequent days following splenectomy, we observed a rapid and persistent increase in platelet count with a peak of 2550 x 109/l. A JAK2 V617F mutation was demonstrated. The normalization and maintenance of platelets was obtained with small doses of anagrelide (0.5mg four doses/week) with RBC transfusion requirements decreasing by 50%.
Conclusion: This patient presented most of the main characteristics of RARS-T except thrombocytosis (note that trisomy 8 has been described in association with RARS-T). Our observation suggests that thrombocytosis could be absent in some patients presenting with a very similar pattern of features as described in RARS-T. We postulate that hypersplenism (and possibly other particular biological characteristics) could, in some cases, mask the complete picture of RARS-T.
ETV6: Its Role in Mouse Development and Leukaemogenesis Using Knock-Out and Knock-In Models.
Authors: Hart Stephen , Duke Veronique , Pannell Richard , Rabbitts Terence , Naresh Kikkeri , Foroni Letizia 
Published: October 2019

Abstract
Disruption of the transcription factor ETV6 (TEL) is believed to play a pivotal role in the development of many types of leukaemia. As well as there being more than 15 ETV6 fusion gene partners described to date, there are other genetic alterations of ETV6 including deletions, point mutations and disruption in the ETV6 promoter region that may contribute to the malignant phenotype. We generated two Etv6 knock-out mouse models (Met1 and Met43) to investigate the role of Etv6 in mouse embryonic development and two knock-in models carrying the t(12;21) and t(9;21) fusion genes to investigate the role of the Etv6-RUNX1 and Etv6-ABL fusion oncoproteins in leukaemogenesis. Etv6-Met1−/− was compatible with full embryonic development. However, from a total of 382 animals generated from the Etv6-Met1+/− cross only 39 were identified as homozygous suggesting some embryonic lethality. A second knock-out construct (Etv6-Met43) was generated in which the second transcription start site at AA position 43 was removed. Of the 235 offspring genotyped from the Etv6-Met43+/− cross, no homozygous animals were identified. Further investigation revealed that Etv6-Met43−/− foetuses lacked definitive haematopoiesis and died between dE10.5–11.5. These data indicate that an Etv6 transcript generated from the methionine at AA position 43 can partially rescue the Etv6-Met1−/− phenotype. No mice homozygous for the Etv6-RUNX1 were identified from the 628 offspring genotyped from the Etv6-RUNX1+/− cross. Further investigation revealed that Etv6-RUNX1−/− foetuses displayed a similar phenotype to the Etv6-Met43−/− animals and died in-utero at a similar time. Etv6-RUNX1+/− animals were fertile and remained well for the first year of life. However, after this time in a group of 91 animals it was noticed that among 41 Etv6-RUNX1+/− animals, the majority were dying from a blastic haematological tumour formation best identified in spleens, at a higher incidence than in the 51 wild-type littermates. Chimeric mice targeted with the Etv6-ABL construct remained well for a short period after birth but all subsequently sickened and died within the first year of life. Upon examination peripheral blood as well as post-mortem organs showed a homogeneous infiltration of granulocytic cells resembling a chronic myeloid proliferation. RT-PCR on RNA isolated from the peripheral blood, bone marrow and spleen of three chimeric animals showed the presence of the fusion gene. Our study demonstrates that Etv6 is essential for mouse embryonic development. The role of Etv6 in malignant transformation is complex and would appear to be dependent on the function of the partner fusion gene rather than on the common Etv6 part of the protein.
Prediction of Survival in Patients with Myelodysplastic Syndrome According to WHO Classification-Based Prognostic Scoring System (WPSS).
Authors: Jang Jun Ho , Kim Kihyun , Jung Chul W. , Park Keon Woo 
Published: October 2019

Abstract
Background Based upon the classification of FAB criteria, International Prognostic Scoring System(IPSS) has been a standard prognostic model to predict survival and progression in MDS. In 2000, the WHO has formulated a new classification of myelodysplastic syndrome(MDS). The aim of this study was to evaluate the prognostic value of WHO classification-based prognostic scoring system(WPSS) in MDS.
Patients and methods One hundred forty-nine patients who were diagnosed as having de novo MDS at the Division of Hematology-Oncology, Samsung medical center, Seoul, Korea, between Dec. 1994 and Feb. 2007, were evaluated retrospectively for clinical and hamatologic features at diagnosis, transfusion dependence, overall survival(OS), and progression to leukemia(LFS). Risk group stratifications in MDS patients were done according to IPSS and WPSS.
Results 18 patients(12.1%), 93 patients (62.4%), 29 patients(29%) and 9 patients(6%) had IPSS risk scores of low, intermediate-1(Int-1), intermediate-2(Int-2) and high, respectively. According to WPSS risk scores, 8 patients(5.4%), 30 patients(20.1%), 41 patients(27.5%), 57 patients(38.3%) and 13 patients(8.7%) were classified to very low, low, intermediate, high and very high risk group, respectively. In IPSS, median OSs of low, Int-1, Int-2 and high subgroup were 65.2, 32.9, 14.3 and 9.1 months respectively (p<0.001). According to WPSS, median OSs of very low, low, intermediate, high and very high risk subgroup were not reached, 55.4, 27.4, 19.0 and 6.2 months respectively (p<0.001). Between subgroups classified according to WPSS, significant differences in OS were noted in low vs. intermediate risk group (p=0.047), in intermediate vs. high risk group (p=0.046) and in high vs. very high risk group(p=0.003) but statistically not significant difference in OS was observed between very low and low risk group (p=0.08). The mean and median OS of the lowest risk group(low risk) in IPSS are 65.33 and 55.43 months, respectively. The mean and median OS of the lowest risk group(very low risk) in WPSS are 102.8 months and not reached, respectively.
Conclusion These data show that WPSS with five risk groups might provide more refined prognostic stratifications of MDS than IPSS with four risk groups. Especially, new prognostic system appears to discriminate a subset of patients with very low risk, who could have long term survival.
Allelic Expression Imbalance of JAK2 V617F Mutant Contributes to Phenotypic Variation in BCR-ABL Negative Chronic Myeloproliferative Disorders.
Authors: Shin Myung-Geun , Kim Hye-Ran , Kim Hyeoung-Joon , Kim Mi-Ji , Kim Hee-Nam , Kim Yeo-Kyeoung , Kim Soo-Hyun , Shin Jong-Hee , Suh Soon-Pal , Ryang Dong-Wook 
Published: October 2019

Abstract
Background: An acquired somatic mutation in the JAK2 gene (V617F) could present the primary causative lesion in BCR-ABL-negative chronic myeloproliferative disorders (CMPD). However, some of the clinical and genetic data implied that the pathophysiological role of JAK2 V617F mutation in the CMPD would be more complex. Quantitative assessment of JAK2 V617F mutation has shown substantial heterogeneity in the genomic DNA. Recently, it has been reported that allelic variation in gene expression is common in the human genome. To test the hypothesis that JAK2 V617F mutant allele could be increased in cDNA, we examined JAK2 V617F mutation status in the genomic DNA and cDNA from a total of 78 patients with BCR-ABL-negative CMPD.
Patients and Methods: Enrolled patients with BCR-ABL-negative CMPD in this study comprised 42 cases of essential thrombocythemia (ET), 26 polycythemia vera (PV), 7 idiopathic myelofibrosis (MF) and 3 unclassifiable (UC) CMPD. A 364-bp PCR product containing JAK2 V617F mutation was bidirectionally sequenced from total BM cells. A quantitative real time PCR-based allelic discrimination assay and pyrosequencing (Pyrosequencer PSQ96) were developed for quantitative analysis of JAK2 V617F mutation status. Homozygous JAK2 V617F mutation was defined if the mutant peak was more than 50% of total peak area.
Results: The proportion of mutant alleles ranged from 36% to 100% in real-time PCR and pyrosequencing analysis. Patients with MF had higher percentages of JAK2 mutant alleles than patients with ET (MF > PV > ET). The prevalence of homozygous V617F mutations was significantly higher in PV patients (73%) than in patients with ET (17%). Allelic expression imbalance of heterozygous JAK2 mutation was common in patients with PV and ET. Interestingly, allelic expression imbalance in patients with MF was not remarkably impaired, but preferential expression of JAK2 mutant allele showed threefold increase from the cDNA compared with the genomic DNA from patients with PV and ET.
Conclusion: Allelic imbalance in the gene expression of JAK2 V617F mutant could provide the underlying mechanisms to elucidate phenotypic variation in BCR-ABL negative CMPD.
Familial Essential Thrombocythemia Showing Spontaneous Megakaryocyte Colony Formation and Acquired JAK2 Mutations without a Germline Mutation in C-MPL or TPO.
Authors: Higgs Jillian R. , Sadek Irene , Neuman Paul E. , Ing Vincent , Berman Jason N. , Greer Wenda L. 
Published: October 2019

Abstract
Essential thrombocythemia (ET) is a chronic myeloproliferative disorder, characterized by increased proliferation of megakaryocytes and elevated platelet counts that usually occurs sporadically. We report a family with 7 affected individuals in three generations, including one individual with a phenotype resembling polycythemia vera, a related disorder. Megakaryocyte (CFU-MK) colony formation occurred in the absence of added cytokines in cultures of peripheral blood from affected family members. Some reports of familial ET have identified mutations in the genes coding for thrombopoietin (TPO), the cytokine that primarily regulates platelet production and its receptor, c-MPL. In this family, the MPL gene was excluded by linkage analysis. Although TPO levels were elevated in most affected family members and evidence for linkage was found between the disease and TPO (𝛉 = 0.0, Zmax = 3.0), a TPO mutation was not identified by DNA sequencing. The JAK2 V617F mutation that has been associated with 50% of sporadic cases of ET was identified as a somatic mutation in the peripheral blood of the two most clinically affected family members. These patients also had the most elevated TPO levels, raising the possibility of an association between JAK2 and TPO production. Further study of familial myeloproliferative diseases will help elucidate the initiating genetic events underlying ET.
Mutational Analysis of Thrombopietin, c-MPL and Jak2 Genes in Essential Thrombothethymia Patients - Identification of Concurrent Mutations of c-MPL and Jak2.
Authors: Ding Jianmin , Komatsu Hirokazu , Iida Shinsuke , Ito Asahi , Yano Hiroki , Ri Masaki , Inagaki Atsushi , Kusumoto Shigeru , Ishida Takashi , Nitta Masakazu , Ueda Ryuzo 
Published: October 2019

Abstract
The molecular pathogenesis in chronic myeloproliferative disorder including essential thrombocythemia (ET) has been recently clarified. We previously identified a novel activating mutation of c-MPL gene (S505N) as a cause of familial ET. The Jak2 mutation (Jak2V617F) is also reported most frequently as a constitutive activating mutation in ET. Here we screened the mutations in the open reading frames of thrombopoietin (TPO), c-MPL and Jak2 in the 26 Japanese (sporadic) ET patients. None had any somatic mutations in TPO. We found Jak2V617F mutation in 7 patients. Interestingly, one of the patients had the c-MPL somatic mutation (W515L). The c-MPL W515L transfectants presented the autonomous STAT5 and MEK1/2 phosphorylation in the absence of the ligand, which show the c-MPL W515L is a constitutive activating mutation for signalling. The concurrent mutations of Jak2V617F and c-MPL W515L are likely to contribute to the pathogenesis of the thrombocythemia in this patient. Now we are focusing on the issue whether the single clone with both of two mutations occupy or the two clones with either Jak2 or c-MPL mutation coexist in the bone marrow of this ET patient (Single cell PCR is on going with the megakaryocytes of this patient).
A Molecular Cytogenetics Profile of Chromosome 9p in CMPD.
Authors: Vaughan Beverley R. , Brazma Diana , Grace Colin , Howard Julie , Nacheva Elisabeth 
Published: October 2019

Abstract
Chronic Myeloproiferative Disorders (CMPDs) form a continuum of haematological malignancies of which the molecular pathogenesis remains obscure. Chronic Myeloid Leukaemia (CML) being the only disorder with a recognisable pathogenomic abnormality, the Ph chromosome. Tyrosine kinases are clearly implicated in the disease pathogenesis, in particular the role of JAK2. It has been shown that over 80% of Polycythaemia Vera (PV) patients and 30% of Essential Thrombocythaemia (ET) patients demonstrate a clonal and recurrent mutation V617F in the JH2 pseudo-kinase domain of JAK2 located on 9p24.1. Array CGH investigations of cell lines, revealed a complex pattern of imbalances affecting the short arm of chromosome 9: on the background of 2–3-fold amplification, a loss of the 9p24.1 region, which harbours the JAK 2 along with a number of other kinases, was repeatedly observed. The aim of this study was to clarify the aCGH observations using a series of BAC DNA probes mapping from the telomere of 9p toward the centromere. Results indicate the presence of imbalances (amplifications & deletions) and rearrangements, involving the region encompassing JAK2. In all CML-BC cell lines the FISH data supports the observation of a relative loss of the 9p24.1 region on the background of amplification of chromosome 9. An on-going study of CMPD and MDS patients with both normal and abnormal karyotypes has revealed imbalances affecting the short arm of chromosome 9. In 23% (7/30) of patients there were imbalances; the majority of these (56%) demonstrated a relative loss of information in this region. The pathegenomic significance of imbalances involving 9p remains unclear. It may however represent an acquired homozygousity as a consequence of mitotic recombination, with a ‘second hit’ removing a wild type allele, leading on to further, as yet un-clarified changes.