bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence for Alternative Lengthening of Telomeres in Chronic Lymphocytic Leukemia Patients.
Authors: Damle Rajendra N. , Banapour Taraneh , Sison Cristina , Allen Steven L. , Rai Kanti R. , Chiorazzi Nicholas 
Published: April 2020

Abstract
Telomere shortening is a consequence of repetitive clonal replication and leads to clonal deletion unless DNA extension and repair occur. All tumors must circumvent this problem by up-regulating mechanisms that lead to chromosomal lengthening. Two mechanisms have been identified that maintain chromosome ends- telomerase that does so by reverse transcription and alternative lengthening of telomeres (ALT) that occurs by homologous recombination. The latter function is characterized by the presence of promyelocytic leukemia protein-associated nuclear bodies (PML-NBs) and the presence of PML-NB is used to mark cells that use this process.
B cell Chronic lymphocytic leukemia (B-CLL) cells with unmutated Ig V genes have shorter mean telomere lengths compared with those exhibiting mutated Ig V genes. In addition, cells with unmutated Ig V genes demonstrate more telomerase activity than their mutated counterparts. The mutated cases show long and heterogeneously elongated telomeres in spite of the absence, in most cases, of detectable telomerase activity. Therefore we determined whether the ALT pathway plays a role in telomere maintenance in B-CLL, using a monoclonal anti-PML antibody and a flow-cytometric assay for assessment of PML protein. Telomerase-expressing Jurkat T cells and murine fibroblasts-L cells served as negative controls for PML staining, whereas the ALT positive Osteosarcoma cell line U2-OS served as a positive control. In a cohort of 20 B-CLL cases, PML protein was detected in all cases regardless of Ig V mutation status. In addition, a similar percentage of cells within the clones contained PML (10 - 90% of the members of unmutated clones and 11–96% of mutated clones), whereas peripheral blood B cells from 6/6 elderly normal donors did not show any PML staining. PML expression was compared with telomere length and telomerase activity in the same cases. The percentage of cells showing PML expression inversely correlated with telomerase activity (r= −0.58; p=0.029). Although in most published reports telomere maintenance by ALT occurs in the absence of telomerase activity, we found ALT (as suggested by PML positive cells) in cells with telomerase activity (detected by the standard TRAP assay). Thus, B-CLL cases can express PML bodies and some B-CLL cells can contain both PML-NB and express telomerase activity. These findings suggest that B-CLL cells can use two distinct mechanisms to assure telomere maintenance and perpetuate clonal survival and expansion.
Expression of Angiogenin in Normal B Lymphocytes and B-CLL Cells.
Authors: Paul Santanu , Allen Steven L. , Rai Kanti R. , Chiorazzi Nicholas 
Published: April 2020

Abstract
Angiogenesis is critical for the clinical progression of hematopoietic malignancies and depends on a series of angiogenic factors. Angiogenin is a potent angiogenic factor produced by the host microenvironment and certain neoplastic cells. The association between angiogenin, cancer progression and poor outcome in solid tumors has been documented, but its significance in B-CLL has not been defined. A previous study suggests that B-CLL patients in Rai stage O with higher angiogenin levels have a better clinical outcome. This is surprising in light of the association of angiogenin levels with progression in solid tumors. Therefore we analyzed angiogenin mRNA and protein expression by the leukemic cells of B-CLL patients in order to correlate the production of this molecule with disease progression in B-CLL.
Angiogenin was expressed in B-CLL cells as well as in B cells of normal donors, although the expression in the former was much higher than in the latter. Q PCR revealed a 7-fold induction in angiogenin-specific mRNA transcription in B-CLL cells (n=10) in comparison to normal B cells (n=13). In addition, angiogenin protein was identified by confocal microscopy both within and on the cell surface of B-CLL cells. All B-CLL cases, regardless of IgV gene mutation status, express angiogenin as defined by FACS. Approximately 85% of the cells that comprise B-CLL clones (n=28) display angiogenin on their surface membranes (range: 55-98%). Furthermore approximately 13% of polyclonal B cells from normal subjects (n=12) also produce angiogenin (range: 1–33%). Using enzyme immunoassay, we also measured serum angiogenin levels and detected significant differences in 66 B-CLL patients (median: 381 ng/mL; range: 185–875) versus 24 age- and sex-matched healthy controls (median: 301 ng/mL; range: 192–536) (P = 0.0056). Surprisingly, there was no correlation between surface and serum angiogenin levels and the different V gene-defined B-CLL subgroups.
Our results show for the first time that a small fraction of normal B cells and all cases of B-CLL express angiogenin transcripts as well as intracellular and surface membrane protein. Angiogenin levels do not correlate with IgV gene mutations status or expression of surface membrane CD38. The role of angiogenin in the pathogenesis and progression of B-CLL needs further study.
Expression Levels of CD38 in Tumor Cells and T-Cells Are of Prognostic Value in B-CLL.
Authors: Tinhofer Inge , Rubenzer Gabriele , Egle Alexander , Greil Richard 
Published: April 2020

Abstract
Purpose: CD38 expression level of tumor cells was identified as predictor for progression, overall survival and response to therapy in B-chronic lymphocytic leukemia. Though CD38 is involved in effector functions of T-cells, the prognostic value of CD38 expression in these cells has not been addressed in B-CLL before.
Patients and Methods: CD38 expression levels in B-CLL cells and T-cells from 170 patients were analyzed by flow cytometry and correlated with clinical and molecular risk parameters.
Results: CD38 expression levels significantly differed not only in the neoplastic clone but also in T-cells from B-CLL patients with low vs advanced stage and stable vs progressive disease. Combined analysis of CD38 in T-cells and B-CLL cells identified 4 subgroups of patients with distinct clinical course. Multivariate analysis including clinical (Rai stage, anemia) and molecular risk parameters (Zap-70 expression levels, IgVH mutational status) identified CD38 expression levels in B-CLL (RR 6.9; 95% CI: 2.4 to 20.2; p=.0004) and T-cells (RR 2.4; 95% CI 1.2 to 4.8; p=.0106) as independent prognostic factors. Furthermore, CD38 expression in T-cells as a risk factor for increased peripheral tumor load and progressive disease was significantly associated with male gender.
Conclusion: Combined analysis of CD38 in tumor cells and T-cells is superior in predicting outcome in B-CLL than either parameter alone. Our data on the prognostic value of CD38+ T-cells in B-CLL in general, and their identification as male risk factor in particular strongly encourage further studies on their role on survival and proliferation of B-CLL cells and the underlying mechanisms.
Is Elevated Serum IL-10 in B-CLL Associated with IL-10 Promoter Polymorphisms?.
Authors: Chu Charles C. , Reese Stephanie T. , Goodwin Leslie O. , Guzowski Dorothy , Chandrasekaran Alamelu , Gawel Craig , Li Wentian , Gregersen Peter K. , Yan Xiao J. , Sherry Barbara , Centola Michael , Allen Steven L. , Rai Kanti R. , Chiorazzi Nicholas 
Published: April 2020

Abstract
Interleukin-10 (IL-10), a cytokine that regulates inflammation, may play an important role in B-cell chronic lymphocytic leukemia (B-CLL), because of the reported association of high serum IL-10 levels with a lower prognosis of survival. Using the Bio-Plex protein array system, we confirmed that B-CLL patients exhibit higher median IL-10 levels (3.54 pg/ml, n=50) as compared to controls (1.28 pg/ml, n=33) (p&lt;0.0001). We are in the midst of determining B-CLL VH gene mutation status and IL-10 levels. To determine if elevated IL-10 levels are due to inherent genetic polymorphisms, we examined three single nucleotide polymorphisms (SNPs) in the proximal end of the promoter region of the IL-10 gene (-1082 A/G, −819 T/C, and −592 A/C) that may affect IL-10 transcription levels. DNA from an overlapping set of 54 B-CLL patients and 48 normals was genotyped using the Transgenomic WAVE system. The difference in allele frequencies at a single locus showed no trend towards significance between groups using the Pearsons chi-square test and Odds Ratios (OR) with 95% Confidence Intervals (CI) for each SNP (-1082 (p = 0.686, OR = 1.122, CI = 0.641–1.966), −819 (p = 0.844, OR = 1.062, CI = 0.585–1.926) and −592 (p = 0.720, OR = 1.116, CI = 0.613–2.031)). B-CLL cases and normal subjects showed no significant departure from Hardy-Weinberg equilibrium in single locus genotype frequencies. Differences in single locus genotype frequencies between B-CLL cases and controls showed no significant differences for each SNP (−1082 (p = 0.600, OR = 1.366, CI = 0.425–4.389), −819 (p = 0.638, OR = 0.727, CI = 0.192–2.749), and −592 (p = 0.638, OR = 0.727, CI = 0.192–2.749)). The haplotype frequencies were calculated using maximum likelihood method based on the observed genotypes. The differences in maximum likelihood haplotype frequencies, between the B-CLL cases and controls, were insignificant (p = 0.754). The haplotype pair genotype frequency differences between the B-CLL cases and controls were also insignificant (p = 0.921). In conclusion, the allele, genotype, and haplotype frequencies of IL-10 SNPs −1082, −819, and −592 show no trend towards significance overall. This suggests that these promoter SNPs do not contribute to elevated serum IL-10 in B-CLL. However, a suggestion of association with VH gene mutation status is being further investigated with a larger sample size.
The Multi-Functional Cellular Adhesion Molecule CD44 Is Targeted by the 8;21 Chromosomal Translocation.
Authors: Wang Yang , Peterson Luke , Zhang Dong-Er 
Published: April 2020

Abstract
CD44 is a type I transmembrane protein and functions as the major cellular adhesion molecule for hyaluronic acid, a component of the extracellular matrix. CD44 is expressed in most human cell types and is implicated in a wide variety of physiological and pathological processes, including tumor cell growth and metastasis. Its importance in acute myeloid leukemia is highlighted by evidence of its high expression in all human acute myeloid leukemias. In addition, the treatment of leukemic blasts with anti-CD44 antibodies promotes their maturation, suggesting a potential differentiation therapy for patients and a possible role for CD44 in the growth and maintenance of leukemic blast/stem cells. We have recently identified the naturally occurring leukemogenic splice variant of the t(8;21) associated AML1-ETO gene, AML1-ETO9a. To understand the molecular mechanism of AML1-ETO-9a involved leukemogenesis, we performed micro-array analysis with a multipotential hematopoietic cell line. Out of the 39,000 transcripts, 24 decreased more than 3.5-fold including SPARC, Mac25 that are reportedly involved in proliferation of different cells. We also identified 75 transcripts with more than 3.5 fold increase that included Sca-1, Runx2 and CD44. Specifically we show that the presence of AML1-ETO9a significantly increased the expression of CD44 at both RNA and protein levels. Furthermore, the CD44 promoter region −709 to −280 bp is responsive to both AML1-ETO9a as well as AML1-ETO. Thus our observations suggest that AML1-ETO and its splice variant AML1-ETO9a are able to promote the expression of the CD44 gene, linking the 8;21 translocation directly to the regulation of an important cell adhesion molecule potentially involved in the growth and maintenance of the acute myeloid leukemia blast/stem cells.
Correlation of JAK2 Mutation and PRV-1 and WT1 Transcript Amount in Myeloproliferative Disorders.
Authors: Serra Anna , Carturan Sonia , Gottardi Enrico , Arruga Francesca , Messa Francesca , Sterpone Paola , Defilippi Ilaria , Rosso Valentina , Catalano Renata , Martinelli Giovanni , Iuliano Francesco , Saglio Giuseppe , Cilloni Daniela 
Published: April 2020

Abstract
Recently, a JAK2V617F mutation has been described in the majority of patients with polycythemia vera (PV), and in a subset of patients with essential thromocythemia (ET) and idiopathic myelofibrosis (IMF). Similarly, PRV-1 has been found overexpressed in many of these patients. The aim of the study was to correlate PRV-1 and WT1 expression with the presence of JAK2 mutation in order to establish whether these markers identify the same subset of patients. Using a Real Time PCR we studied the expression level of PRV1 and WT1 in 330 patients including 26 IMF, 156 PV, 122 ET, 16 HES. 10 familiar forms of PV were included. In addition a control group of 50 healthy subject and 60 reactive conditions were studied All the patients were analyzed for the presence of JAK2 mutation using the ABI Prims 3100 genetic analyzer. We found that JAK2 mutation was present in 50 % of IMF, 93% of PV and 55% of ET and 6% of HES. PRV-1 was increased in 84% of IMF, 98% of PV and 90% of ET and it was not increased in HES. WT1 was increased in 99% of IMF, 45% of PV and 42% of ET and 100% of HES. No mutations of JAK2 were detected in normal subjects or in reactive conditions. Both WT1 and PRV1 were expressed at low levels in normal subject (for PRV1 the mean value of 2-Delta Delta Ct was 2,05; range 0,05–5,46; for WT1 mean value WT1 copies/104 ABL copies of 4; range 0–20). The mean value of WT1 copies/104 ABL copies in IMF was 306 (p=0,00004 compared to normal controls), in PV was 156 (p=0,0001), in ET was 202 (p=0,0002) and in HES was 161 (p=0,0004). PRV1 mean value in IMF was 144 expressed as 2−Delta Delta Ct, and it was 423 in PV and 290 in ET. Moreover the correlation between the three markers allowed to establish that both WT1 and PRV1 were higher in JAK2 mutated samples when compared to wild type JAK2 with a p value of 0,001 for WT1 and 0,004 for PRV1. In spite of these we were able to identify a subset of patients affected by IFM characterized by increased values of PRV1 and WT1 but not by JAK2 mutation (34%) and a small subset 15% characterized only by WT1 overexpression. Only 5% of PV and 35% of ET patients expressed only PRV-1 but not JAK2 mutation and WT1 expression. HES patients overexpressed WT1 but not PRV1 and only one patient presented the JAK2 mutation. Finally 10 patients affected by familiar form of PV were studied. All the subjects showed normal PRV-1 expression but high level of WT1 transcript and 9 out of 10 presented the JAK2 mutation. This study demonstrates that the combination of all these markers is probably useful for a correct diagnosis of these patients but further studies are required to stratify these patients and to better classify them according to the presence of molecular lesions.
Tel-PDGFβR Specifically Induces Interferon-Stimulated Genes.
Authors: Kim Hani , Barber Dwayne L. 
Published: April 2020

Abstract
Chromosomal translocations involving tyrosine kinases play a significant role in human leukemia. Chronic myeloid leukemia (CML) is associated with the recurrent chromosomal translocation, BCR-ABL (t(9;22)(q34;q11)). Chronic myelomonocytic leukemia (CMML) is linked to TEL-PDGF-β Receptor (PDGFβR) (t(5;12)(q33;p13)) fusion. Another TEL fusion, TEL-JAK2 (t(9;12)(p24;p13) has been observed in CMML and Acute Lymphoid Leukemia. All three fusion proteins induce leukemia-like diseases in animal models, and this is attributed to the constitutive tyrosine kinase activity, which leads to dysregulation of their respective downstream signaling pathways. The downstream targets include STAT transcription factors, MAP kinases, and PI3 kinase. On the other hand, little is known about the gene transcription regulated by these fusions.
The objective of our study is to determine whether BCR-ABL, TEL-PDGFβR and TEL-JAK2 induce distinct gene expression patterns when expressed in cell lines and retrovirally transduced bone marrow cells. Each fusion was expressed in an IL3-dependent murine myeloid cell line, Ba/F3. The specific inhibitor, Imatinib mesylate, was utilized to control the activation/inhibition of BCR-ABL and TEL-PDGFβR, and an inducible system was utilized for TEL-JAK2. Upon activation of the fusion protein, cells were collected at various time-points for cell cycle and microarray analysis (Affymetrix MOE430A). We utilized 8 hr, 12 hr, 24 hr and 1 wk time points. Our rationale was to monitor gene expression changes through the first cell cycle and then to examine the fingerprint at a steady state point.
Analysis of the 1 wk data reveals that a subset of genes are co-regulated (2-fold, p&lt;0.05) by BCR-ABL, TEL-PDGFβR and TEL-JAK2 (Pim1, Id1b, Podxl, Cxcr4, Gp49b and Scin). Interestingly, analysis of the TEL-PDGFβR induced genes (10-fold, p&lt;0.05) revealed a significant overlap with Interferon-Stimulated Gene (ISG) dataset including Cxcl-10, Gbp1, Gbp2, Isg20, Ccl-5, Stat1, Irf7, Serpine-1 and Mx1. Genes identified in this microarray study have been confirmed by Q-PCR in Ba/F3 cells and confirmatory experiments in primary bone marrow cells transduced with each fusion protein are underway. In addition, we will determine whether the transcription of these targets is dependent on STAT1 by utilizing bone marrow cells from STAT1−/− mice. In conclusion, our data reveals that oncogenic chromosomal translocations activate both distinct and co-regulated gene expression and reveal a novel and specific role of Interferon-Stimulated Genes in signaling pathways downstream of TEL-PDGFβR.
ICSBP Activates Transcription of the Gene Encoding Neurofibromin 1 in Differentiating Myeloid Cells.
Authors: Huang Weiqi , Saberwal Gurveen , Zhu Chunliu , Eklund Elizabeth A. 
Published: April 2020

Abstract
Previous studies in murine models and human myeloid malignancies indicate that the interferon consensus sequence binding protein (ICSBP) functions as a leukemia tumor suppressor. Previously identified ICSBP target genes include genes encoding gp91phox and p67phox (components of the phagocyte respiratory burst oxidase), the Toll like receptor 4, and other genes involved in mediating the phagocyte inflammatory response. Transcription of these target genes involves interaction of ICSBP with PU.1 and/or interferon regulatory factor 1 (IRF1), and is restricted to mature phagocytic cells. These results predict that ICSBP-deficiency would be associated with terminal differentiation block and immune dysfunction. However, the phenotype of ICSBP −/− mice is dominated by development of a myeloproliferative disorder which evolves to acute myeloid leukemia. Therefore, we used the chromatin immuno-precipitation technique to identify novel ICSBP target genes which might be involved in the ICSBP tumor suppressor effect. We identified the gene encoding neurofibromin 1 (the NF1 gene) as an ICSBP-target-gene. We found that ICSBP activates NF1 transcription during cytokine induced differentiation of myeloid progenitor cells. Because Nf1 protein has ras-GAP activity, increased Nf1-expression down regulates cytokine-induced ras activity, resulting in proliferation arrest during myeloid cell differentiation. In the current studies, we investigate the mechanism by which ICSBP activates NF1-transcription. We find that ICSBP is part of a multi protein complex that binds to and activates a cis element in the NF1 gene. This complex also includes the ets protein PU.1 and interferon regulatory factor 2 (IRF2). We find that tyrosine phosphorylation of ICSBP in response to hematopoietic cytokines is required for assembly of this transcriptional activation complex and therefore NF1-transcription. Identification of NF1 as an ICSBP target gene represents a mechanism for ICSBP-leukemia-suppression. These studies also provide the first indication of the importance of NF1-transcriptional regulation to the control of cytokine-induced proliferation in differentiating myeloid cells.
Enhanced In Vivo Homing of Uncultured and Selectively Amplified Umbilical Cord Blood CD34+ Cells by Co-Transplantation with Cord Blood Derived Unrestricted Somatic Stem Cells.
Authors: Chan Shing Leng , Choi Michael S.K. , Wnendt Stephan , Kraus Morey , Teng Eileen , Leong Hwei Fen , Merchav Shosh 
Published: April 2020

Abstract
Mesenchymal stem cells have been implicated as playing an important role in stem cell engraftment. A new pluripotent population of umbilical cord blood (UCB)-derived Unrestricted Somatic Stem Cells (USSCs), with intrinsic and directable potential to develop into mesodermal, endodermal and ectodermal fates, has recently been identified and characterized (1). In this study we evaluated the capacity of USSCs to influence the homing of UCB -derived CD34+ cells into the marrow and spleen of NOD/SCID mice. Cultured USSCs were co-transplanted with CFDA-labeled cord blood CD34+ cells into sublethally irradiated NOD/SCID mice. Femurs and spleens were harvested 16 hrs thereafter and the percentage of CD34+ cells determined by flow cytometry.
USSCs induced a significant enhancement of CD34+ cell homing to both bone marrow and spleen (2.2 ± 0.3 and 2.4 ± 0.6 -fold, respectively; p&lt;0.05). Similar findings were obtained with frozen USSC samples that had been thawed prior to transplantation. The effect of USSCs was specific, as no homing enhancement could be observed by co-transplantation of CD34+ cells with lineage-positive UCB cells, which contain T, B and mature myelo-erythroid cells. Enhanced marrow homing by USSCs was unaltered by extensive culture passaging of the cells, with a similar degree of enhancement observed for both early (p5) and late (p10) passage USSCs (1.7 ± 0.1 and 1.9 ± 0.1 -fold, respectively). Enhanced homing was dose-dependent, detectable at USSC/CD34+ ratios of 1:1 and above.
USSCs were also found to enhance the homing of day 14 cells harvested from cultures of selectively amplifiedTM, ex-vivo expanded UCB lineage-negative (lin-) cells. The relative proportion of homing CD34+ cells within the culture-expanded cell population, was unaffected by USSC co-transplantation. Our findings thus demonstrate that USSCs enhance the homing of UCB hematopoietic stem cells and suggest a clinical potential for these cells in facilitating engraftment under conditions of limiting cord blood stem cell numbers.