bluuebunny/crossref_metadata_2025_split huggingface dataset:
Point Mutation and Alternative Splicing in the ABL Kinase Domain as a Mechanism for Imatinib Resistance.
Authors: Chen Rong , Potts Steven , Ma Wanlong , Kantarjian Hagop , Giles Francis , Albitar Maher 
Published: April 2020

Abstract
Missense point mutations in the region encoding the ABL tyrosine kinase domain have been reported in approximately 35% of patients with imatinib-resistant chronic myeloid leukemia (CML). The reported mutations result in reactivation of the BCR-ABL tyrosine kinase. Screening patients with imatinib-resistant CML, we identified 42 different mutations in the ABL tyrosine kinase domain-encoding region, 2 of which were silent (no amino acid change): A864G and G909A. The A864G mutation was associated with a 54-nucleotide reduction in the length of the mRNA transcript, representing a loss of nucleotides 1089-1143; the G909A mutation was associated with a normal-length transcript. The nt1089-1143 transcript deletion represents a partial exon deletion in which the first half of exon 8 is skipped, suggesting that A864G leads to abnormal splicing. Splicing is regulated by 6- to 8-nucleotide exonic splicing enhancer (ESE) and exonic splicing silencer (ESS) motifs recognized by the SR proteins (a family of splicing factors). We therefore used ESEfinder to examine whether A864G or G909A alter ESE motifs, which could block the ability of SR proteins to recognize and bind. This search showed that A864G is at the 7th position of an AGCTGCAG ESE motif, a binding site for SR35, and is within 35 bp of the intron-exon junction. In total, ESEfinder predicted 18 putative SR35-binding ESEs within 50 bp of the intron-exon junction, covering 20% of the kinase domain. The AGCTGCAG motif is conserved in primates (chimpanzees and monkeys) but not in rodents, while A864G is found in mice Although similar links cannot be made with the G909A mutation, these data suggest that imatinib resistance may develop in some patients through alternative splicing and the expression of a truncated (or potentially elongated) protein.
Cas-L Suppresses Progression of Leukemia Induced by p210Bcr/Abl.
Authors: Seo Sachiko , Nakamoto Tetsuya , Suzuki Takahiro , Takeshita Masataka , Ichikawa Motoshi , Chiba Shigeru , Ogawa Seishi , Honda Hiroaki , Oda Hideaki , Kurokawa Mineo 
Published: April 2020

Abstract
Cas-L (Crk-associated substrate lymphocyte type) which is also known as Hef1/Nedd9 was first identified as a protein tyrosine-phosphorylated upon stimulation of β1 integrin in peripheral T cells. Cas-L is a member of Cas family proteins, with a single Src homology (SH) 3 domain and multiple YXXP motifs (substrate domain) and functions as a docking protein in focal adhesions. Bcr/Abl is a fusion oncoprotein that induces chronic myelogeneous leukemia and acute lymphoblastic leukemia. Previous studies reported that Cas-L is tyrosine-phosphorylated by p190Bcr/Abl in lymphoid cells. In this study, we found that Cas-L is also expressed in myeloid cells, which suggests functional interaction between CasL and p210Bcr/Abl. To elucidate the role of Cas-L in leukemia induced by p210Bcr/Abl, we generated the Cas-L-deficient p210Bcr/Abl transgenic mice. The mice displayed early development of myeloproliferative disease compared with the p210Bcr/Abl transgenic mice, which results in the early death of those mice. Pathologically, increased infiltration of myeloid cells into several tissues was detected in the absence of Cas-L. No significant differences were detected in the proliferation assay using bone marrow cells from those mice. Taken together, Cas-L seems to negatively regulate the progression of p210Bcr/Abl-induced leukemia presumably by inhibition of extramedullary hematopoiesis.
Chronic Myeloid Leukemia (CML) Treatment in Brazil: Results of the Rio Grande do Sul Cooperative Group for Treatment of CML.
Authors: Fogliatto Laura M. , Guterres Ines , Capra Marcelo Z. , Fernandes Mario S. , Schaan Marisa , Hellwig Tania , Zago Aletea , Schilling Marco , Almeida Denise , Wisinteiner Sabrina , Lorandi Roque , Winck Adriana , Zardo Adriana , Silla Lucia M.R. 
Published: April 2020

Abstract
Background: Imatinib mesylate (Glivec,Novartis), an inhibitor of Bcr-abl tyrosine kinase, is currently being used in the treatment of CML with hematological, cytogenetic and molecular response. In Brazil, this drug is approved by Health Department for chronic phase (CP) as a second line drug and as first line for accelerated (AP) and blastic phase (BP). Rio Grande do Sul (RS) Cooperative Group for Treatment of CML coordinates the treatment of this disease in Rio Grande do Sul, the southern most state of Brazil that differs from the north part of the country regarding climate, population profile (mostly European descendents) and a high number of farm workers.
Methods: 211 CML Ph+ patients are presently being treated in RS. Sex distribution: 96 male and 115 females, aged 11–80 years (median 48 y);166/211 in CP, 42/211 in AP and 11/211 in BP. Imatinib daily dose is 400 mg (CP) and 600 mg (AP and BP). 166/211 patients are in treatment with imatinib and 32/211, interferon or hydroxyureia. In imatinib group, 144/166 patients are in complete hematologic response and 57/166 in complete cytogenetic remission.
Conclusions: in Brazil, imatinib treatment is limited by economic problems and the drug is used latter in course of disease. This may compromise the results, as seen in the low cytogenetic complete response described above. We are now investigating this results in order tofind other related factors.
Rituximab Is the Essential Treatment Modality That Underlies the Significant Improvement in Short and Long Term Outcome of Patients with Advanced Stage Follicular Lymphoma - A 10 Year Analysis of GLSG Trials.
Authors: Hiddemann Wolfgang , Hoster Eva , Buske Christian , Dreyling Martin , Kneba Michael , Hallek Michael , Lengfelder Eva , Wandt Hannes , Unterhalt Michael 
Published: April 2020

Abstract
Recent reports have shown a significant improvement of overall survival (OS) in patients with advanced stage follicular lymphoma (FL) over the last few decades. In order to identify the essential treatment modalities that underlie these observations two consecutive study generations of the German Low Grade Lymphoma Study Group (GLSG) covering a ten year period were analyzed for remission rates (RR), time to treatment failure (TTF) and OS. The analysis was adjusted for risk factors using the FLIPI, and type of primary induction therapy (including Rituximab or not). Between 1996 and 2005 complete data sets of 1332 patients with stage III or IV FL who were in need of therapy were collected. Therapy comprised prospective randomized comparisons of CHOP versus MCP in GLSG study ’96 (1996 – 2000) and CHOP versus R-CHOP in GLSG study ’00 (1996 – 2005). The entry criteria and the distribution of risk factors were identical in both study generations. The type of chemotherapy had limited impact on RR with CHOP being superior to MCP (86% versus 77%, p=0.0094) but no impact on TTF or OS. Patients treated in GLSG ’00 had a significantly better RR (94% versus 88%, odds ratio 0.47, p=0.0002), a longer TTF (median 48 months versus 32 months, relative risk 0.66, p&lt;0.0001) and a longer OS (89% versus 78% at four years, relative risk 0.42, p&lt;0.0001) as compared to patients of GLSG ’96. Multiple Cox regression analysis revealed Rituximab as being the determinant responsible for the differences in RR (adjusted odds ratio 0.45, p&lt;0.0001) and TTF (adjusted relative risk 0.39, p&lt;0.0001). With regard to OS, after adjusting for Rituximab as most relevant determinant (adjusted relative risk 0.44, p = 0.0064), the difference between the study generations still remained significant (adjusted relative risk 0.57, p = 0.0071). Hence, Rituximab is the essential treatment modality that underlies the improvement in short and long term outcome of patients with advanced stage FL. Most probably, more effective salvage therapy with Rituximab containing combinations account also for the additional improvement in OS.
Comparison of Erythroid Response (ER) Rates in Myelodysplastic Syndromes (MDS) Patients Treated with Different Therapeutic Strategies Using Epoetin Alfa (EPO).
Authors: Moyo Victor , Lefebvre Patrick , Bourezak Ahmed , Yektashenas Behin , Mundle Suneel 
Published: April 2020

Abstract
Background: EPO continues to be a primary therapeutic choice for the treatment of anemic patients with low to intermediate-1 risk MDS. Initially, without standardized response criteria, ER rates were modest. Recently, a meta-analysis of EPO monotherapy studies in MDS demonstrated a significant improvement in ER rates with the application of standardized International Working Group criteria (IWGc) for response evaluation (Moyo V et al. 2006 ASCO Annual Meeting Proceedings Part I. Vol 24, No. 18S (June 20 Supplement), 2006: 6572). This meta-analysis was expanded to determine the impact of higher doses of EPO or the addition of granulocyte or granulocyte-macrophage colony stimulating factor (G- or GM-CSF) to EPO on ER rates (defined as major + minor response).
Methods: A systematic review and data extraction of studies from PubMed, ASCO and ASH proceedings from 1990–2006 in MDS patients treated with EPO monotherapy or EPO + G-/GM-CSF combination therapy was performed. Pooled estimates of ER rates were calculated in studies defining ER rates without IWGc application (non-IWGc) for EPO monotherapy at Standard (std) dose (30,000–40,000 Units per week) in comparison to studies that defined ER rates using IWGc, where EPO was used at std dose or high dose (60,000–80,000 Units per week) or in combination with G-/GM-CSF.
Results: A total of 23 studies were evaluated in this analysis. As shown in the table below the IWGc studies using EPO at std dose or high dose or in combination with G-/GM-CSF demonstrated significantly higher ER rates than the non-IWGc studies (p&lt;0.001 for all comparisons). Among the IWGc studies, those using a higher dose of EPO alone had significantly higher ER rates as compared to studies using std dose EPO monotherapy (p&lt;0.001) or EPO + G-/GM-CSF combination (p=0.018). In addition, among the studies using EPO combinations, those using EPO + G-CSF (Total studies-3, evaluable N= 96) showed ER rates of 55.2% as compared to 42.8% (p=0.142) for the EPO + GM-CSF combination (Total studies-3, evaluable N= 56).
Conclusions: The findings from this present meta-analysis confirm the impact of IWGc on ER rates for EPO therapy previously observed. Further improvement in ER rates was observed with the use of higher doses of EPO alone or the combination of EPO + G-/GM-CSF. Increasing the EPO dose appeared to have a greater impact on ER than the addition of G-/GM-CSF.
Non-IWGc IWGc Study Group EPO Std Dose EPO Std Dose EPO High dose EPO + G-/GM-CSF Starting EPO Dose Units/week 30,000–40,000 30,000–40,000 60,000–80,000 30,000–40,000 No. of Studies 8 5 4 6 No.of Evaluable Patients 262 393 196 152 ER Rates (%)(95% CI) 32.1 (26–38) 47.8 (43–53) 63.3 (57–70) 50.7 (42–59)
Familial Myelodysplastic Syndromes with Centromere Instability of Chromosome 1 Origin.
Authors: Raaschou-Jensen Klas , Andersen Mette Klarskov , Nielsen Bendt , Kjeldsen Eigil , Kjeldsen Lars 
Published: April 2020

Abstract
Myelodysplastic syndrome (MDS) is a highly heterogeneous disease. The etiology involves both environmental and genetic factors. Identification of new pathogenetic mechanisms may have important impact on the choice of treatment as well as the development of new treatment options. Familial disease gives a unique opportunity to study those mechanisms. Familial occurrence of MDS is rare and mainly associated with autosomal recessive genetic syndromes such as Fanconi anaemia, Bloom syndrome, Diamond-Blackfan syndrome and megakaryocytic thrombocytopenia. Cytogenetic abnormalities are in general seen in 50% of MDS cases. Most frequently, abnormalities involving chromosome 5 or 7 are observed, which has also been described in rare cases of familial MDS. We here present a unique family in which a father and two of his three children were diagnosed with refractory anemia (RA) with cytogenetic aberrations resulting in three different translocations involving chromosome 1q and resulting in trisomy of 1q. Trisomy 1q is often seen in sporadic MDS, but the unbalanced translocations observed in this family may originate from inherited centromere instability of chromosome 1. The genetic background for the observed centromere instability could be a DNA methylation deficiency, which we plan to investigate further.
G-CSF Increases Hematological Response among Patients with Myelodysplasia Treated with Azacitidine.
Authors: Rossetti James M. , Falke Eric , Shadduck Richard K. , Latsko Joan M. , Kramer Wendy , Lister John 
Published: April 2020

Abstract
Rationale: Myelodysplastic syndrome (MDS) is characterized by peripheral blood cytopenia, a major cause of morbidity and mortality. Two current treatments that may ameliorate cytopenia in MDS are azacitidine (aza) and hematopoietic growth factors. When used alone in MDS, erythropoietin (epo) and G-CSF are reported to increase the hemoglobin level and the neutrophil count, respectively. Additionally, epo and G-CSF may work synergistically to improve anemia and neutropenia. This study examined whether the combination of growth factors and aza would be more effective than aza alone for the treatment of MDS.
Methods: We identified 86 MDS patients treated at our institution who received an average of 10.8 cycles of aza. Forty-nine (49) of these patients also received either epo, G-CSF or both during the course of their aza treatment, while 37 did not receive hematopoietic growth factors. These 2 groups did not differ significantly either in number of cycles of aza received (p=0.34) or FAB MDS subtype (p=0.50). Hematological responses were tabulated by International Working Group criteria and compared using chi-square statistics.
Results: Patients treated with aza alone had a 51% (19/37) overall hematological response rate (OHR). Patients who received aza + epo (A + E) had a 50% (6/12) OHR and when compared to aza alone (A), was not statistically different (p=0.9). Patients who received aza + G-CSF +/− epo (A + G +/− E) had an 84% (31/37) OHR versus 51% (25/49) in patients who did not receive G-CSF (A +/− E) (p=0.003). When the group A + G +/− E was compared to A +/− E there was a statistically significant difference in favor of A + G +/− E in erythroid (77% vs. 37%; p=0.001) and platelet (72% vs. 47%; p=0.04) response, but no difference in neutrophil response (71% vs. 67%; p=0.9).
Conclusion: In patients with MDS treated with aza the addition of G-CSF improved OHR, erythroid and platelet response. Surprisingly, neutrophil response was not improved. The biological basis for these observations suggests an effect upon erythroid and megakaryocytic lineages. We postulate that G-CSF may have an anti-apoptotic effect as has been previously demonstrated when used in combination with epo.
Acceleration of Leukemogenesis in CREB Transgenic Mice by Retroviral Insertional Mutagenesis.
Authors: Sandoval Salemiz , Sakamoto Kathleen , Deepa Shankar 
Published: April 2020

Abstract
Cyclic adenosine monophosphate response element binding protein (CREB) is a 43 KDa transcription factor that promotes cell growth and survival, and is a downstream target of growth factor signaling in myeloid cells. We previously reported that CREB is overexpressed in greater than 60 percent of acute myeloid leukemia (AML) patients and is associated with an increased risk of relapse and decreased survival. Transgenic mice that overexpress CREB in the myeloid lineage develop a myelodysplastic/myeloproliferative (MDS/MPD) syndrome with splenomegaly and aberrant myeloid proliferation after one year, but not leukemia. To accelerate leukemogenesis and identify genes that specifically cooperate with CREB, we infected CREB transgenic and wild type (WT) mice with the retrovirus, MOL4070LTR (kindly provided by Linda Wolff, NCI). MOL4070LTR has been shown to accelerate the onset of leukemia in mice by insertionally activating or mutating cooperating genes. Fifteen newborn CREB transgenic and nineteen control WT mice were injected intraperitoneally with virus (1×105 PFU). The infected mice were monitored at regular intervals for signs and symptoms of disease. We analyzed peripheral blood counts for evidence of blasts and performed physical examination for signs of abdominal distention and lethargy. Three out of the fifteen CREB transgenic mice infected with the virus developed disease at 6 to 7 months of age. WT mice, now 10 to 12 months of age, have yet to develop disease. All three CREB transgenic mice infected with MOL4070LTR had increased white blood cells, hepatosplenomegaly, and abnormal blood smears. One of the three CREB transgenic mice with leukemia developed AML with circulating blasts in the peripheral blood and infiltration of the spleen and liver with myeloblasts by histologic examination. The two other CREB transgenic mice died from acute lymphoblastic leukemia. Our preliminary results demonstrate that CREB transgenic mice but not WT mice infected with MOL4070LTR develop leukemia. We are currently identifying possible oncogenes using DNA from the mouse that developed AML. Our results suggest that CREB has the potential to induce acute leukemia in mice; however, additional mutations are required.
Circulating Endothelial Cells and Circulating Endothelial Progenitor Cells in Polycythemia Vera.
Authors: Hoeg Rasmus T. , Jobe Dean A. , Asp Krista E. , Callister Steven M. , Meyer Lori A. , Mathiason Michelle A. , Cole Craig E. , Bottner Wayne A. , Farnen John P. , Go Ronald S. 
Published: April 2020

Abstract
Background: Angiogenesis and thrombosis, two conditions associated with perturbation of the vascular endothelium and increased CECs, are frequently observed in PV. We performed this study to quantify and characterize CECs in patients with PV and to determine whether CEC profile is associated with thrombotic complications. We also quantified CEPs in a subgroup of patients.
Methods: We used flow cytometry to prospectively analyze CECs and CEPs in the whole blood of healthy patients (n=20) and patients with PV (n=30; 13 treated with hydroxyurea, 12 undergoing phlebotomy alone, and 5 never treated). CECs (CD45−/CD31+/CD146+) were quantified and characterized to determine their apoptotic (annexin stain) or activation (CD106+) states. Cells with CD45−/CD31+/CD133+/VEGF-R2+ immunophenotype were considered CEPs.
Results: CEC levels in PV patients were higher compared to healthy controls (median 53 cells/mL [range, 11–392] vs 18.5 cells/mL [range, 4–66]; P&lt; .0001). However, the proportions of apoptotic (17.3% [range, 0–87.5] vs 25.9% [range, 0–57.1]; P= .87) and activated (0.7% [range, 0–28.6] vs 0% [range, 0–57.1]; P= .14) CECs were similar between the two groups. In PV patients with high levels (≥2 SD above control mean or ≥53 cells/mL) of CECs (n=14), 5 (36%) developed thromboses. Four (25%) of 16 PV patients with CEC levels similar to healthy controls developed thromboses. The rates of thrombosis between the groups were not statistically different (P= .69). In addition, CEC count, activation, and apoptosis were similar between the hydroxyurea-treated group and the group not treated with hydroxyurea. We detected low numbers of CEPs in PV patients (n=25) that were similar to controls (4 cells/mL [range, 0–100] vs 8 cells/mL [range, 0–60]; P= .34).
Conclusions: CECs, but not CEPs, are significantly increased in PV patients. However, there appears to be no association between CEC number, activation or apoptotic state and the development of thromboses. In addition, hydroxyurea therapy does not appear to effect endothelial cells.
In Vitro Erythroid Cell Expansion Analysis in Polycythemia Vera.
Authors: Yoon Donghoon , Bruchova Hana , Agarwal Archana M. , Prchal Josef T. , Prchal Jaroslav F. 
Published: April 2020

Abstract
Polycythemia vera (PV) is an acquired myeloproliferative clonal stem cell disorder characterized by cytokine hypersensitivity. The erythroid colony forming assay has been useful in PV diagnosis. However, studies aiming to elucidate molecular mechanism in PV pathogenesis often require large numbers of cells from a specific erythroid stage. For this purpose, we had adapted the mouse expansion assay described by Karur et al (Blood, 2006 in E-Pub) and differential display method described by Zhang et al (Blood, 2003, 102; 3938) to develop a human erythroid expansion protocol. In this study, we used peripheral blood mononuclear cells (PB-MNCs) from PV patients and healthy donors, and expanded them along erythroid lineage in 21 day culture. Through the culture, we took samples at 8 timepoints (days 1, 7, 9, 11, 14, 16, 19, 21) to evaluate differentiation patterns. We had generated 5 different regions using CD71 (transferrin receptor) and CD235a (glycophorin A) and characterized these regions by standard morphology analysis. This protocol allowed differentiation of PB-MNCs to all erythroid stages ending with late normoblast, reticulocyte, and mature erythrocytes (which do not survive well in this culture environment).
The erythroid differentiation and proliferation patterns were different between PV and normal. In the first week of culture, there was no significant proliferation difference observed between PV and normal. In contrast, the differentiation progressed more rapidly in PV, likely reflecting the differentiation of Epo independent PV population (since the first week culture contains no Epo). In the second week of culture (Epo present), there was a markedly increased expansion of PV erythroid cells. However, the differentiation pattern of PV resembled that of normal.
In conclusion, we demonstrated that our in vitro expansion method allows expansion of PB-MNCs along erythroid lineage with 60~80% stage homogeneity as to the stage of differentiation in both PV and normal. The differences of differentiation and proliferation pattern between PV and normal reflected the expected biological behavior of erythroid progenitors. Thus, the expansion protocol is useful to study molecular mechanism of PV pathogenesis, which requires large number of erythroid progenitors of various stages.