bluuebunny/crossref_metadata_2025_split huggingface dataset:
The beta1-Tubulin Binding Protein RanBP10 Plays a Critical Role for Platelet Discoid Shape and Hemostasis
Authors: Schulze Harald , Fleischhauer Silke , Meyer Imke , Wannack Martin , Kunert Stefan 
Published: April 2020

Abstract
Blood platelets in the circulation are released from megakaryocytes (MKs), their precursor cells in the bone marrow. Mature MKs are located at the blood vessels and release platelets into the blood stream by intermediate structures referred to as proplatelets. Every MK can release up to a thousand virtually identical platelets. During this fragmentation process every single platelet is equipped with a rather constant number of assorted granules and a peripheral microtubule ring consisting of several coiled filaments. 8–12 microtubule filaments are found on average in the coil, which is essential for maintaining the platelet discoid shape. Generating these dynamic microtubule filaments at the very cell periphery in the absence of classical microtubule nucleating factors is strictly dependent on de novo nucleation of filaments. Beta1-tubulin is a MK/platelet-specific and the predominant isoform present in proplatelets and platelets. Mice lacking beta1-tubulin are thrombocytopenic and reveal platelet spherocytosis. In humans, a Q43P mutation in the beta1-tubulin gene Tubb1 also leads to large and spheric platelets. We have recently identified RanBP10 as a cytoplasmic beta1-tubulin binding protein that is selectively expressed in hematopoietic tissues like bone marrow and MKs. RNA interference (RNAi)- mediated RanBP10 ablation in primary MKs resulted in the collapse of long microtubule filaments whereas retrovirally forced overexpression of RanBP10 led to a marked increase in microtubule filaments, most likely by number or augmented bundling. RanBP10 harbors guanine nucleotide exchange factor activity toward Ran by exchanging GDP with GTP. As a local increase in Ran-GTP precedes nucleation of non-centrosomal microtubules in other cell types this mechanism might explain how positional information about new microtubule filaments is provided in the cell periphery of mature and proplatelet elaborating MKs. We generated a gene trap-mediated mouse model for RanBP10 deficiency. MKs derived from nullizygous animals phenocopied the collapse of microtubule filaments found by RNAi. Although RanBP10 was dispensable for overall platelet biogenesis with counts about 90–95% of normal, the ultrastructural analysis revealed that loss of RanBP10 protein resulted in a significant decline in the elliptic coefficient: Mutant platelets were more spherical and electron micrographs showed a wider variety in both microtubule filament number and coil localization including additional and incomplete coiling. Most intriguingly, RanBP10- deficient mice demonstrated a markedly prolonged bleeding time compared to littermate controls in a standardized tail bleeding assay. Platelets from nullizygous animals failed to respond normally to ADP by CD62P expression in flow cytometry. Our data thus suggest that RanBP10 plays a critical role in maintaining the tightly controlled platelet shape and function and that RanBP10 is essential for hemostasis.
Myeloid Cell Differentiation Arrest by Mir-125b-1 in Myelodysplasic Syndrome and Acute Myeloid Leukemia with the T(2;11)(p21;q23) Translocation
Authors: Bousquet Marina , Quelen Cathy , Rosati Roberto , Mas Véronique Mansat-De , Bastard Christian , Lippert Eric , Talmant Pascaline , Lafage-Pochitaloff Marina , Leroux Dominique , Gervais Carine , Viguie Franck , Lai Jean-Luc , Terre Christine , Delsol Georges , Dastugue Nicole , Mecucci Cristina , Brousset Pierre 
Published: April 2020

Abstract
Most chromosomal translocations in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) involve oncogenes which are either up-regulated or form part of new chimeric genes. The t(2;11)(p21;q23) translocation has been cloned in 19 cases of MDS and AML. In addition to this, we have shown that this translocation is responsible for a strong up-regulation of miR-125b (6 to 90 fold). In vitro experiments revealed that miR-125b was able to block monocytic and granulocytic differentiation of leukemic cells and primary CD34+ human blasts. Therefore, miR-125b up-regulation may represent a new mechanism of myeloid cell transformation and myeloid neoplasms carrying the t(2;11) translocation define a new clinico-pathological entity.
Acute Lymphoblastic Leukemia in a Case of Ring Chromosome
Authors: Türkmen Seval , Muller Sebastian , Mundlos Stefan , Henze Günter , Lode Holger 
Published: April 2020

Abstract
Ring chromosome 13 is a rare chromosomal abnormality. The classic mode of formation of a ring chromosome is breakage of the ends of both arms of a chromosome wit fusion of the broken ends resulting in the loss of the distal fragments. The clinical phenotype will depend on loss of genetic material.. Here, we report for the first time the development of an acute lymphoblastic leukaemia (ALL) in a patient with a constitutional ring chromosome 13. The chromosome analysis of the bone marrow revealed a large deletion that involved the Retinblastoma (RB1) gene. The possible role of (RB1) gene for leukemogenesis is discussed in this patient
Increased Expression of PD-1 on CD4+ T Cells from Patients with Chronic Lymphocytic Leukemia
Authors: Sartor Mary M , Gottlieb David J 
Published: April 2020

Abstract
Although the predominant finding in patients with chronic lymphocytic leukemia (CLL) is an expansion of monoclonal B lymphocytes, a polyclonal expansion of T cells co-exists in CLL patients. Allogenic stem cell transplants for CLL suggest that a significant graft versus leukaemia effect mediated through recognition of minor MHC or leukaemia specific antigens can be achieved. Since it appears that the immune system and probably T cells recognise CLL cells, it is possible that one or more T cell defects might contribute to the initiation or maintenance of a clone of CLL lymphocytes. PD-1 is a coinhibitory molecule that is expressed on T cells in patients with chronic viral infections. It has been suggested that PD-1 expression might be a marker of cell exhaustion due to antigenic overstimulation. We examined the expression of PD-1 and its naturally occurring ligands PD-L1 and PD-L2 on both B and T cells in patients with CLL and compared this with expression on normal peripheral blood mononuclear cells. We found that PD-1 was expressed on over 10% of CD4+ T cells in 7 of 9 cases of CLL (mean 22±16%) but not on CD4+ T cells in any of 9 normal donors (mean 0±0%), p=0.0009. There was no difference in PD-1 expression on CD8+ or CD14+ PBMCs from CLL patients and normal donors (for CD8+ 24±21% and 19±16% for CLL and normals; for CD14+ 58±16% and 71±31% for CLL and normals). More than 10% of CD5+/19+ CLL cells expressed PD-1 in 7 of 10 cases (mean 18±18%) while more than 10% of normal B cells from 6 of 7 donors also expressed PD-1 (mean 49±30%). We examined the expression of PD-1 on naïve, central memory, effector memory and terminally differentiated subsets of CD4+ cells (CD62L+CD45RA+, CD62L+CD45RA−, CD62L−CD45RA− and CD62L−CD45RA+ respectively) from CLL patients and normal donors. The expression of PD-1 was higher on CD4+ cells from CLL patients in all subsets. The effect was most prominent in the effector memory subset (mean 54±4% for CLL patients versus 26±17% for normal donors, p=0.02). We looked for expression of PD-L1 and PD-L2 on T cells, B cells, monocytes and NK cells from CLL patients and normal donors. PD-L1 was only expressed on monocytes (mean 30±23%) and NK cells (mean 14±19%) from CLL patients and on monocytes from normal donors (mean 35±26%). There was no expression of PD-L2 on any cell type in either CLL patients or normal donors. We conclude that there is increased expression of the co-inhibitory molecule PD-1 on CD4+ T cells in patients with CLL. Ligation of PD-1 by PD-L1 expressed on monocytes or NK cells could inhibit immune responses to tumor and infectious antigens leading to persistence of clonally expanded cells and predisposition to opportunistic pathogens.
Recurrent Chromosome Abnormalities Define Non-Overlapping, Unique Subgroups of Tumors in Chronic Lymphocytic Leukemia Patients with Known Karyotypic Abnormalities
Authors: Jimenez-Zepeda Victor H , Chng Wee Joo , Braggio Esteban , Kay Neil , Leis Jose , Fonseca Rafael 
Published: April 2020

Abstract
Background B-cell chronic lymphocytic leukemia (B-CLL) is a well-defined clinical entity with heterogeneous molecular and cytogenetic features. Chromosome aberrations could be associated to specific CLL clinical features and outcomes and their impact on clonal evolution should have been addressed by using temporal analysis. In order to demonstrate the role of temporal analysis in CLL we conducted a comprehensive karyotypic survey of a large number of CLL cases with already known genetic aberrations to fully describe their meaning in terms of biological evolution.
Methods A total of 1749 karyotypes were retrieved from the Mitelman Database of Chromosome Aberrations in Cancer. A matrix depicting the 360-band human chromosome ideogram was created. Regions that were either lost or gained in more than 3% of the cases were retained and identified as recurrent imbalances. Early and late imbalances were defined according to the appearance on the complex karyotypes. Descriptive statistics were used to summarize the genetic abnormalities.
Results The median chromosome number and the median number of abnormalities per tumor (NAPT) were 46 and 1 respectively. (Figure 1 A and 1B) The most common abnormality seen was trisomy 12 which occurred in 29% (508 cases) followed by 13q14del (10.34%), 13q13del (6.63%) and add14q32 (6.63%). The temporal analysis revealed +12, 13q-, −17, 17p-, −Y and −X to be early imbalances (TO&lt;5), followed predominately by a late loss with TO=5–10.5 (11q-). Hierarchical clustering suggested there are different groups including:
trisomy 12, 13q-, 11q-, and 6q-, which at least in this clustering analysis appeared to be mutually exclusive.
In summary, we can conclude that overall CLL is a neoplasia that shows remarkable chromosome stability even when only abnormal karyotypes are evaluated. Interestingly, clustering analysis suggests there are non-overlapping, unique subsets of CLL cases where trisomy 12 is the most common and along with 13q-emerged as early events on CLL clonal evolution.
Figure 1A. Chromosomes distribution in chronic Lymphocytes Leukemia karyotypes Figure 1A. Chromosomes distribution in chronic Lymphocytes Leukemia karyotypes Figure 1b. Chronic Lymphocytes Leukemia and Number of Abnormalities Per Tumor (NAPT) distribution Figure 1b. Chronic Lymphocytes Leukemia and Number of Abnormalities Per Tumor (NAPT) distribution Figure Figure
The Prognostic Significance of Positive Direct Antiglobulin Test in Chinese Patients with Chronic Lymphocytic Leukemia
Authors: Xu Wei , Li Jianyong , Cao Xin , Zhu DAN-Xia , Yao Lin , Liu Qiong , Qiao Chun , Wu Yu-Jie 
Published: April 2020

Abstract
Chronic lymphocytic leukemia (CLL) is the most common type of adult leukemias in the Western countries, however, infrequent in the Eastern. Autoimmune hemolytic anemia (AHA) is a complication in chronic lymphocytic leukemia (CLL). The direct antiglobulin test (DAT) may be positive at some time during the disease course in up to 35% of cases, but overt AHA occurs less frequently. The aim of the study was to explore the prognostic impact of positive DAT in Chinese patients with CLL and its correlation with other prognostic factors, including Binet stages, lymphocyte count in peripheral blood, lactate dehydrogenase (LDH), β2-microglobulin (β2-MG), IgVH mutation status, ZAP-70, CD38 and cytogenetic abnormalities. Out of the 80 Chinese patients with CLL, positive DAT was found in 21 (30.6%) cases. The incidence of positive was 12.5% in Binet A, 23.8% and 44.4% in Binet B and C, respectively. The incidence of positive DAT was significantly increased at Binet C, compared with Binet A (P=0.006), and the presence of higher LDH and β2-MG levels correlated strongly with positive DAT (P=0.006 and P=0.004, respectively). Patients with unmutated IgVH genes had higher incidence of positive DAT than did patients with IgVH mutations (P=0.042), and positive DAT was also associated with higher level of ZAP-70 and CD38 (P=0.004 and P&lt;0.001, respectively). We also analyzed positive DAT in different cytogenetic subgroups. Higher incidence of positive DAT was found in patients with unfavorable cytogenetic aberrations (deletion in 17p13 or 11q22) in contrast to lower level in good risk cytogenetics (deletion in 13q as the sole abnormality) (P = 0.002). Positive DAT was associated with poor outcome. Survival analysis showed that the patients with positive DAT had significantly shorter OS (mean, 106.3 months) (95% CI, 74.7 to 137.8 months) than the patients negative DAT (mean, 151.5 months) (95% CI, 122.3 to 180.6 months) (P=0.024). Patients treated with fludarabine were not likely to remain DAT positive and to change from negative to positive (P=0.209). In conclusion, DAT status provides a new prognostic indicator and correlates with other clinical or laboratory prognostic factors, and might be applied for the assessment of prognosis in patients with CLL.
Serum Thymidine Kinase Level in Chinese Chronic Lymphocytic Leukemia and Its Correlation with Other Prognostic Factors
Authors: Li Jianyong , Xu Wei , Yu Hui , Qiu Hongxia , Qiao Chun , Wu Yu-Jie , Liu Qiong , Zhu Danxia , Miao Kourong 
Published: April 2020

Abstract
Objective To investigate serum thymidine kinase (TK) level in Chineses patients with chronic lymphocytic leukemia (CLL) and its correlation with other prognostic factors, including Binet stages, absolute lymphocyte count (ALC), lactate dehydrogenase (LDH), immunoglobulin heavy-chain variable region (IgVH) gene mutation status, ZAP-70 protein and CD38 expression level, and cytogenetic aberrations.
Methods Serum TK1 level in 39 CLL patients was detected by TK monoclonal antibody (Anti-TK mAb) and enhanced chemiluminecence (ECL). IgVH mutation status was detected by multiplex PCR and sequencing of purified PCR amplification products. A panel of monoclonal antibodies and multiparametic flow cytometry were employed to immunophenotype and determine the expression of ZAP-70 protein and CD38. A panel of probes and interphase fluorescence in stu hybridization (FISH) were used to detect cytogenetic aberrations including 6q-, 11q-, +12, 13q-,17p- and IgH translocation.
Results The level of TK1 was higher in CLL patients that in normal control (P&lt;0.05). TK1 level was not signifigantly correlated with sex, age, Binet stages, CD38, and cytogenetic aberrations. Patients with higher level of ALC, LDH, ZAP-70 and unmutated IgVH genes had higher levels of TK1 than those with lower level of ALC, LDH, ZAP-70 and mutated IgVH genes (P=0.018, P=0.018, P=0.038 and P=0.030, respectively).
Conclusions Serum TK1 level significantly correlates with ALC, LDH, ZAP-70 and IgVH mutational status, and could be a predictive marker of IgVH mutation status. Serum TK1 might be applied for the assessment of prognosis in Chinese patients with CLL.
CD38 Expression above 20% Predicts Disease Progression in Chronic Lymphocytic Leukemia and Is a Useful Prognostic Marker Where Cytogenetic and Molecular Markers Are Not Available
Authors: Alipour Sina , Leitch Heather , Vickars Linda M , Foltz Lynda M , Galbraith Paul F , Leger Chantal S , Ramadan Khaled M 
Published: April 2020

Abstract
The prognostic significance of CD38 expression and the cut off value has not been fully investigated. As CD38 is readily available test in patients with chronic lymphocytic leukemia (CLL), we investigated its role in prediction of disease progression when a cut off value of 20% is used. Progression free survival (PFS) was defined as the time from diagnosis to first treatment or last follow up. An electronic database search of pts with CLL who presented at St Paul’s Hospital between 1969 and 2007 was performed. Among 465 pts with CLL, 161 pts (35%) had their CD38 expression measured by flow cytometry. CD38 expression and its association with other prognostic factors such as age, Rai stage, lymphocyte count at diagnosis, gender and other immunophenotypic makers were analyzed. Out of 161 pts, positive CD38 expression (&gt;20%) was found in 36 patients (22%). Comparing the baseline characteristics of the CLL pts with CD38+ and negative disease, we found CD38 positivity more common in male pts than in female pts (p=0.03). Also patients with CD38 positive disease tend to present with more advanced stage disease (p=0.056). Progression free survival at 2, 5 and 10y for the CD38+ CLL pts was 89%, 61% and 41% respectively compared with 95%, 81% and 62% for the CD38 negative group (p=0.03). Univariate analysis revealed the following factors as significant or marginally significant for disease progression: CD38+ (p=0.03), male gender (p=0.07), Rai stage (p&lt;0.0001), lymphocyte count above 20 ×109/l at diagnosis (p&lt;0.0001), CD5 expression &lt;10% (p=0.01). On multivariate analysis, only disease stage at diagnosis (p&lt;0.0001) and CD38 expression above 20% (p=0.04) retained significant and were predictive for disease progression. We conclude that CD38 expression above 20% at the time of diagnosis can be prognostically useful and predicts for disease progression and along with Rai staging can provide inexpensive tool to follow and monitor patients with CLL.
Table: Characteristics of patients with CLL based on CD38 ≥20% and &lt;20%
Parameter CD38 ≥20% (%) CD38&lt;20% (%) p value* *for differences between the groups. Number 36 125 Sex: M/F (ratio) 22/14 (1.6:1) 66/60 (1.1:1) 0.03 Age above 60 y 21 (58) 81 (65) 0.2 Rai stage: 0, 1+2, 3+4 20, 11, 5 (55, 31, 14) 100, 17, 1 (80, 14, 0) 0.056 Lymphocyte count above 20×109/l 9 (25) 23 (18) 0.3 CD5 &lt;10% 6 (16) 29 (23) 0.3
Fig: Progression free survival for patients with CLL based on CD38 expression, cut off level 20%. Fig:. Progression free survival for patients with CLL based on CD38 expression, cut off level 20%.
Nucleolar Stress and p53 Mediated Erythroid Failure in Diamond Blackfan Anemia
Authors: Sieff Colin , Lodish Harvey F. 
Published: April 2020

Abstract
The discovery that several ribosomal protein genes can be mutated in DBA suggests that ribosomal protein gene mutations may account for many or all cases of DBA, and focuses attention on the ribosome. While experiments in yeast and mammalian cells show that RPS19 depletion or mutation leads to a block in ribosomal RNA biosynthesis, this result does not explain why erythropoiesis is so severely affected in DBA. We hypothesize that during fetal development immature erythroid cells proliferate more rapidly than other lineages and therefore require very high ribosome synthetic rates to generate sufficient capacity for translation of erythroid specific transcripts that must take place before these unique cells enucleate. To test this kinetic hypothesis we measured RNA biogenesis in primary mouse fetal liver cells and reported previously that during the first 24 hours cell number increases 3–4 fold while, remarkably, there is a 6-fold increase in RNA content during the same period, suggesting that the cells accumulate an excess of ribosomal RNA (80% of measured RNA) during early erythropoiesis. Retrovirus infected siRNA RPS19 knockdown cells show reduced proliferation of FACS sorted GFP positive cells at 48 hours. Although the cell yield is reduced, the differentiation pattern of the surviving GFP positive cells is similar to that of the controls. While quantitative RT-PCR analysis shows that RPS19 mRNA is rapidly depleted, Western analysis during this time course does not show a deficiency of RPS19 protein. This suggests strongly that the proliferative defect is not due to insufficiency of RPS19 protein, and is more likely due nucleolar stress induced by the block in ribosome biogenesis. Molecular consequences could lead to redistribution of cell cycle proteins normally resident in the nucleolus with consequent p53 mediated cell cycle arrest and or apoptosis. To test this hypothesis we used a culture system that allows expansion without differentiation of immature cells in SCF, EPO, IGF-1 and dexamethasone. Under these conditions proliferation of siRNA expressing precursors is reduced with an increased proportion arrested in G0/G1 in the knockdown cells. Furthermore, p53 is increased in the knockdown cells. Taken together, these data suggest that RPS19 insufficient cells undergo a nucleolar stress response and erythroid cells proliferate poorly because of p53 mediated cell cycle arrest and apoptosis.
Treatment of Chronic Lymphocytic Leukemia with a Hypomethylating Agent Induces Expression of NXF2, An Immunogenic Cancer Testis Antigen
Authors: Dubovsky Jason A , McNeel Douglas G , Powers John J. , Sotomayor Eduardo M. , Pinilla Javier 
Published: April 2020

Abstract
Critical to success of active immunotherapy against cancer is the identification of immunologically recognized cancer-specific proteins with low tolerogenic potential. Cancer testis antigens (CTAs) in particular, fulfill this requirement as a result of their aberrant expression restricted to cancer cells and lack of expression in normal tissues bypassing tolerogenic mechanisms against self. Although CTAs have been extensively studied in solid malignancies little is known regarding their expression in chronic lymphocytic leukemia (CLL). Using a two-pronged approach we evaluated the immunogenicity of 29 CTAs in 22 patients with CLL and correlated these results to RTPCR data from CLL cell lines and patient cells. We identified IgG specific antibodies for one antigen, NXF2 and confirmed this response by ELISA and Western blot. We found that treatment of CLL with 5-aza-2′-deoxycytidine can induce expression of NXF2 that lasted for several weeks after treatment. Treatment also increased levels of MHC and costimulatory molecules (CD80, CD86, and CD40) necessary for antigen presentation. In addition, we identified other promising antigens such as NY-ESO-1 and MAGE which may have potential immunotherapeutic application. Our findings suggest that NXF2 could be further pursued as an immunotherapeutic target in CLL, and that treatment with demethylating agents could be exploited to specifically modulate CTA expression and effective antigen presentation in malignant B-cells.