bluuebunny/crossref_metadata_2025_split huggingface dataset:
Combined Disruptions of the Ribosomal Protein s19 and Pim1 Kinase Genes Are Associated with Increased Myeloid/Erythroid Cellularity and Reduced Apoptosis
Authors: Fröjmark Anne-Sophie , Badhai Jitendra , Schuster Jens , Klar Joakim , Thuvesson Maria , Ellis Steven , Dahl Niklas 
Published: April 2020

Abstract
Diamond Blackfan anemia (DBA) is characterized by reduced proliferation and increased apoptosis of erythroid progenitors. Approximately 25% of patients are heterozygous for mutations in the gene encoding ribosomal protein S19 (RPS19). The molecular mechanisms behind DBA remain unclear and RPS19 was recently shown to interact with PIM1 kinase. To elucidate the phenotypic and cellular effects of this interaction we generated mice strains with the genotypes Rps19 +/− Pim1 +/+; Rps19 +/+ Pim1 −/− and Rps19 +/− Pim1 −/−. We analyzed the mice for peripheral blood and bone marrow parameters as well as apoptotic markers in primary bone marrow cells. The double mutant mice (Rps19 +/− Pim1 −/−) show normal growth and life span with increased white and red blood cell counts when compared to wild type, Rps19 heterozygous, and Pim1 null mice, respectively. Analysis of proteins in bone marrow cells shows that the combination of Rps19 insufficiency and Pim1 deficiency is associated with increased levels of Stat5 as well as the anti-apoptotic markers Mcl-1, Bcl-2 and Bcl-XL. The pro-apoptotic markers Bak, Caspase-3 and p21 show decreased levels whereas p53 remains unchanged. These findings suggest a co-operative effect of Rps19 insufficiency and Pim1 deficiency on cell proliferation in murine hematopoiesis.
Characterization of Novel Natural Mutations in Telomere Binding Protein Factor (TIN2) Identified in Patients with Bone-Marrow Failure Syndromes
Authors: Xin Zhong-Tao , Calado Rodrigo , Savage Sharon A , Lansdorp Peter M , Young Neal S , Ly Hinh 
Published: April 2020

Abstract
We report for the first time potential pathogenic mutations in a known telomeric DNA binding protein factor (TIN2) in patients with acquired aplastic anemia. We examined samples collected from 142 AA patients and 289 healthy controls and found several natural sequence changes in the TINF2 gene, which encodes for the TIN2 protein. Lymphocytes collected from patients with TINF2 variant alleles appeared to grow slower in culture than cells collected from either healthy individuals or those who carried inconsequential polymorphic TINF2 sequence changes (SNPs), consistent with the fact that telomere lengths in these patients were shorter than those of healthy individuals of similar age. We introduced natural mutations in the TIN2 promoter region into a TIN2-promoter driven luciferase reporter plasmid and examined their effect on driving luciferase reporter expression. Using a similar approach, we defined both the regulatory DNA elements and transcriptional factors that control TINF2 gene expression under normal physiological condition. Results obtained from these studies were validated in gel-shift (EMSA) and chromatin immunoprecipitation (ChIP) assays. In addition to mutations in the promoter region, numerous natural mutations were identified in the coding region of the TINF2 gene in patients with AA or Dyskeratosis Congenita (DC). We used co-immunoprecipitation assays to test the effect of natural mutations in disrupting TIN2’s interaction with its known protein partners TRF1, TRF2 and TPP1 of the shelterin complex that protects chromosome ends. The results obtained from these studies will be discussed. To our knowledge, this is the first comprehensive functional analysis of all known mutations in the TINF2 gene in patients with AA or DC. This study offers an insight into how TINF2 mutations can lead to telomere shortening effect and to limited marrow stem-cell reserve and renewal capacity in patients with various forms of bone-marrow failure syndromes.
Age-Adjusted Telomere Length Is Not Associated with Variation in Hematological Parameters in Ageing Women
Authors: Fleury Isabelle , Provost Sylvie , Belisle Claude , Busque Lambert 
Published: April 2020

Abstract
Background. Telomeres play a crucial role in maintaining physical integrity of chromosomes. In the absence of telomerase, telomere length (TL) shortens with each cell division up to a critical threshold where cellular senescence occurs. TL is inversely correlated with age, is longer in women than in men, and demonstrates a strong heritability. Normal blood counts are maintained through out life by an extraordinary number of cell divisions rendering telomere maintenance primordial to prevent stem cell exhaustion. In fact, some cases of bone marrow failure syndromes, such as aplastic anemia and dyskeratosis congenital, have been linked to mutation in the telomerase gene; and stressed hematopoiesis, such at it occurs during the first year following allogeneic bone marrow transplantation induces TL shortening. We hypothesized that individuals with shorter TL may have lower blood counts and a decreased bone marrow reserve. The evaluation of TL as a potential biomarker of ageing hematopoiesis is important in the context of bone marrow transplantation performed with increasingly old donors.
Methods. We measured TL in 1583 women, predominantly aged over 60, all originating from 288 French-Canadian families using a real-time quantitative PCR method that measures the number of telomere repeats relatively to the copy number of a single copy number gene. Telomeres were adjusted for age. Pearson or Spearman correlations were used to determine association between age-adjusted TL (aTL) and hematological parameter according to, respectively, whether or not a normal distribution was observed for these data. A Bonferroni correction was further applied to set the statistical significance threshold.
Results. aTL varied significantly between individuals of the cohort, but no correlation was detected with hemoglobin levels (−0,001; p=0,978), mean corpuscular volume (−0,031; p=0,403); leucocytes (0,055; p=0,139); neutrophils (0,078; p=0,036), monocytes, (0,059; p=0,113), eosinophils (−0,032; p=0,394) and platelets (0,030; p=0,428) counts.
Conclusion. Based on our analysis, TL do not predict blood cells counts in ageing women and may not be a useful biomarker for donor selection. This could also suggest that there is a threshold beyond which TL has an effect on hematopoiesis and that point was not reached in our cohort.
Comparative Genomic Analysis of CLL Genomes Using Affymetrix 50K SNP Versus SNP 6.0 Arrays
Authors: Malek Sami , Wright Whitney , Li Cheng , Shakhan Sajid , Ouillette Peter 
Published: April 2020

Abstract
Unbiased analysis of CLL genomes using intermediate resolution SNP arrays has identified subtypes of del13q14, del17p and del11q as well as high genomic complexity CLL. Additional information on genomic aberrations and polymorphic copy number variants (CNVs) in CLL may be obtained through application of the latest generation ultra-high-density SNP array technology to CLL genome analysis. We have analyzed 50 paired DNA samples (sorted CD19+ cells versus sorted CD3+ cells) from CLL patients with del13q14 type I and del17p on the Affymetrix SNP 6.0 array platform that were previously analyzed on Affy 50K arrays. We have catalogued all somatically acquired lesions as well as all CNVs. In support of data analysis we have refined the software tools PLUT, LOH tool version 2 and dChipSNP.
Results: In this cohort of 50 CLL cases in which we had previously identified a total of 98 subchromosomal losses and gains using the 50K SNP array platform, we have now identified 141 such lesions using the SNP 6.0 arrays. Of these CLL cases, 68% had identical lesion calls, 30% of cases displayed more lesions on the 6.0 arrays than on the 50K arrays and only one case had one lesion not identified using the SNP 6.0 array platform. Thus SNP 6.0 arrays allowed for significantly improved short lesion detection, detection of CNVs and improved measurements of genomic complexity in CLL. The breaks of del13q14 type I and del17p lesions were mapped with unprecedented resolution and in some cases have been localized to genomic regions less than 1 kb in length, thus allowing for PCR-based cloning of breaks. CNVs were identified throughout the genome, and were found in combination with monoallelic, somatically acquired genomic lesions (del17p, del13q14 and others) spanning such CNVs, resulting in patchy biallelic (homozogous) genomic losses within these lesions. Such a mechanism of biallelic gene loss (CNV plus paired, somatically acquired subchromosomal gene loss), occurs in otherwise monoallelic deletions and may contribute to the biology of monoallelic lesions in many cancers. As one example, CNVs were identified in CD3+ DNA from CLL patients that are located at approximately 49.448–49.508 Mb physical position on chromosome 13 that converted to homozygous loss in patients with monoallelic del13q14. These CNVs encompassed parts of DLEU2, TRIM13 and KCNRG but did not include the del13q14 resident miR cluster (miR15a/16-1). Such CNVs within del13q14 may have a role in the biology of CLL as they may result in gene expression changes that mimic somatically acquired del13q14 lesions.
Acute Myeloid Leukemia Induced by MLL-ENL Is Cured by Oncogene Ablation despite Acquisition of Complex Genetic Abnormalities
Authors: Horton Sarah J. , Walf-Vorderwülbecke Vanessa , Chatters Steve J. , Sebire Neil J. , de Boer Jasper , Williams Owen 
Published: April 2020

Abstract
Chromosomal translocations involving the Mixed-Lineage-Leukemia (MLL) gene on chromosome 11q23 are frequent in infant acute leukemia and give rise to the formation of MLL-fusion genes. Several studies have addressed the importance of MLL-fusion activity for the initiation and maintenance of hematopoietic transformation. However, the dependence of established leukemias on MLL-fusion activity has not been previously addressed. We have developed a model for conditional expression of MLL-ENL in hematopoietic progenitor cells, in which expression of the fusion oncogene is turned off by doxycycline. In this study, immortalized myeloid cells conditionally or constitutively expressing the MLL-ENL fusion gene were used to induce acute myeloid leukemia (AML) in vivo. Primary recipients developed AML with a mean latency of 81.4 (±4.8) days. Secondary recipients developed AML with much shorter latencies than primary recipients regardless of whether the leukemic cells were freshly transplanted (26.8 (±6.8) days) or cultured in vitro for one month prior to transplantation (18 (±3.9) days). Genetic analysis revealed that some leukemic cells had acquired gross chromosomal abnormalities such as trisomy 6 or gains and losses of chromosome regions, which were not detected in the immortalised cells from which they were derived. Despite the acquisition of additional genetic abnormalities, the leukemic cells remained dependent upon MLL-ENL expression in vitro and in vivo. The leukemic cells terminally differentiated into neutrophils upon doxycycline treatment in vitro and established leukemias regressed following administration of doxycycline to recipient mice in their drinking water. Leukemic regression was accompanied by the complete loss of leukemic cells from the peripheral blood and differentiation of leukemic cells in the spleen. In 7 out of 34 doxycycline treated mice, remission was not sustained and the leukemias relapsed. However, most of these were shown to have acquired constitutive expression of MLL-ENL. This study demonstrates that leukemic cells are addicted to MLL-ENL expression and suggests that targeting the transcriptional/signalling networks established by MLL-fusion oncogenes in patients with 11q23 rearrangements would be a major therapeutic advance.
Frequently Occurring B-CLL Antibodies Recognize Apoptotic Cells That Expose Non-Muscle Myosin Heavy Chain IIA
Authors: Chu Charles C , Catera Rosa , Didier Sebastien , Zhang Lu , Agagnina Briana , Allen Steven L , Rai Kanti R , Chiorazzi Nicholas 
Published: April 2020

Abstract
B-cell chronic lymphocytic leukemia (B-CLL) is a disease caused by the clonal expansion of a B lymphocyte expressing a unique monoclonal antibody (mAb) of a defined amino acid sequence. At least 27% of B-CLL patients share mAbs with very similar sequences, suggesting common antigen reactivity. A frequently occurring subset of B-CLL patients (at least 49 worldwide) carries an unmutated mAb with a nearly identical or stereotypic sequence that is characterized by a heavy (H) chain encoded by IGHV1-69, IGHD3-16, and IGHJ3 and a light (L) chain generally encoded by IGKV3-20. mAbs from this stereotypic subset (called subset 6) bind a characteristic cytoplasmic protein in human cells. We have recently shown that this protein is non-muscle myosin heavy chain IIA (MYHIIA).
Because MYHIIA is an intracellular protein, we hypothesized that MYHIIA becomes exposed on the cell surface during apoptosis, allowing the mAb of the B-CLL cell to interact with MYHIIA. In this report, we provide evidence that subset 6 mAbs recognize MYHIIA-containing apoptotic cell structures.
Apoptosis of the human T cell line (Jurkat), either spontaneous, or induced by treatment with camptothecin was assessed phenotypically by nuclear DNA rearrangement revealed by immunohistochemical staining with propidium iodide (PI). Costaining with rabbit anti-human MYHIIA followed by fluorescein isothiocyanate (FITC) labeled donkey anti-rabbit IgG revealed that MYHIIA becomes exposed during apoptosis in structures distinct from those containing fragmented nuclear DNA. PI costaining with recombinant subset 6 B-CLL IgG1 mAb and FITC labeled goat anti-human-IgG antibody shows that this B-CLL mAb binds similar apoptotic structures. Finally, Jurkat cells stained with subset 6 B-CLL mAb as before and rabbit anti-human MYHIIA followed by Rhodamine Red labeled donkey anti-rabbit IgG demonstrate that the B-CLL mAb colocalizes with MYHIIA containing structures.
To further study this observation, Jurkat cell apoptosis was assessed by flow cytometry after staining with 7-AAD and Annexin V-Phycoerytherin (AV-PE). Costaining with anti-MYHIIA shows that anti-MYHIIA is exposed in both early (7-AAD+ AV-PE−) and late (7-AAD+ AV-PE+) apoptotic cells, but not in live (7-AAD−, AV-PE−) cells. Similarly, costaining with subset 6 B-CLL mAb demonstrates binding in both early and late apoptotic cells, but not live cells. Intriguingly, not all apoptotic Jurkat cells are MYHIIA+ or B-CLL mAb+.
In summary, subset 6 B-CLL mAbs react with early and late apoptotic cells exposing MYHIIA. Reactivity with a specific apoptotic cell structure(s) may result in the maintenance and expansion of the leukemic clone.
Germline Genes Specific to Chronic Lymphocytic Leukemia (CLL) and Genes Common to CLL, Lymphoplasmacytic Lymphoma/Waldenström’s Macroglobulinemia, and Other Non-Hodgkin Lymphomas Are Important in Susceptibility
Authors: Landgren Ola , Kristinsson Sigurdur Y , Liang Xueying Sharon , Turesson Ingemar , Bjorkholm Magnus , Caporaso Neil E. , McMaster Mary L. , Chanock Stephen , Goldin Lynn R. 
Published: April 2020

Abstract
Background. Evidence from multiply affected families, case-control and population-based registry studies implicate a role for genetic factors in chronic lymphocytic leukemia (CLL). Population-based studies have found CLL and non-Hodgkin lymphomas (NHLs) to aggregate in families. The aim of this study was to expand our understanding on the role of susceptibility genes in CLL and other lymphoproliferative malignancies.
Methods. Using the population-based Swedish Population-, Cancer-, and Multigenerational registries, we identified all CLL patients (n=9,717) diagnosed from 1958–2004 with linkable first-degree relatives (N=26,947). We also obtained information on 38,159 matched controls and their 107,223 first-degree relatives. Cancer risks in relatives of CLL patients were compared with those in relatives of controls using marginal survival models. In parallel, we conducted a candidate gene association study in unrelated familial lymphoma cases (44 CLL, 71 Waldenström’s macroglobulinemia (WM)) from our clinical studies of high risk families (which were selected for having multiple cases of either CLL or WM) compared to 107 spouses from the same families. We tested 1536 single nucleotide polymorphisms (SNPs) in 152 candidate genes in several pathways including apoptosis, DNA repair, immune response, and oxidative stress using a custom Illumina genotyping platform.
Results. In our population-based study, we found relatives of CLL patients to have an increased risk for CLL (relative risk [RR]=8.5, 95%CI=6.1–11.7), lymphoplasmacytic lymphoma (LPL)/WM (RR=4.0, 95%CI=2.0–8.2) and other NHLs (RR=1.7, 95%CI=1.4–2.2), but not for Hodgkin lymphoma, multiple myeloma, or other hematologic tumors. In our SNP-based study, we found several genes (e.g., IL-10, BCL-2, TRAIL, and TRAILR1) to be significantly associated with both familial CLL and WM. In particular, a SNP in the promoter region of IL-10 (rs1800890, −3575T&gt;A), which has been previously detected in other NHL case-control studies, was associated with both CLL and WM.
Conclusions. We conclude that germline genes specific to CLL and genes common to CLL, LPL/WM and other NHLs are important in susceptibility. We found consistent patterns in both our population-based study and our clinical high-risk families. Our findings for BCL-2, TRAIL, and TRAILR1 highlight the important role of apoptosis pathways in the etiology of these lymphomas. Better characterization of early genetic lesions will ultimately provide clues to pathogenesis and allow identification of novel molecular targets.
The Role of CD137 and Its Ligand in Chronic Lymphocytic Leukemia (CLL)
Authors: Baessler Tina , Buechele Corina , Krusch Matthias , Schmiedel Benjamin J , Kanz Lothar , Salih Helmut R 
Published: April 2020

Abstract
Tumor immunosurveillance is dependent on the reciprocal interaction between tumor cells and anti-tumor immunity mediated e.g. by NK cells. This has led to the concept of tumor immunoediting, which incorporates the multitude of mechanisms underlying this dual tumor- and immune-sculpting interaction. Various members of the TNF/TNFR family modulate differentiation, proliferation, activation, and death of both tumor and immune effector cells. Very recently the TNFR family member CD137 has been shown to be induced on NK cells by Fc receptor triggering indicating that not only the Fab region but also the Fc part of a given antibody may be responsible for effects attributed to CD137 modulation (Lin et al., Blood2008, 112: 699). Thus we here studied the role of human CD137 and its cognate counterpart, the CD137 ligand (CD137L) in the interaction of CLL with NK cells. High levels of CD137L expression were detected on B-CLL cells in all investigated patients (n=40). Incubation of CLL cells in the presence of an immobilized CD137-Ig fusionprotein significantly induced the release of the immunoregulatory cytokine TNF demonstrating that CLL-expressed CD137L was capable to transduce bidirectional signals. Furthermore, we found that NK cells of CLL patients displayed substantial CD137 expression. While being absent on resting NK cells, CD137 expression was upregulated on the CD56dimCD16+ but not the CD56brightCD16− NK cell subset of healthy donors upon activation e.g. with IL-2 or IL-15. In addition, CD137 was also induced on NK cells after incubation in supernatants of PBMC of CLL patients. Surprisingly, disruption of CD137-CD137L interaction in cocultures of allogenic NK cells with patient CLL cells by blocking CD137 antibody caused a significant increase in NK cell cytotoxicity. The observed inhibitory effect of CD137L on NK cell reactivity was confirmed in cytotoxicity assays using CD137L-transfectants with mock-transfectants as control. Furthermore, blocking CD137-CD137L interaction also substantially enhanced Rituximab-induced antibody dependent cellular cytotoxicity in an allogenic setting. Importantly, CD137 blockade also substantially enhanced CD107a expression as a surrogate marker for granule mobilization on autologous NK cells within PBMC of B-CLL patients, and this effect was observed both in the absence and more pronounced in the presence of Rituximab. Thus, expression of functional CD137L by CLL cells impairs anti-tumor immunity by diminishing both direct and antibody-dependent cellular cytotoxicity of allogenic and autologous NK cells. Modulation of the CD137-CD137L system might therefore be a suitable therapeutic approach in strategies like antibody therapy which rely on a sufficient NK cell anti-tumor response.
Abnormal Serum Free Light Chain Ratios Are Associated with Earlier Time to First Treatment and Poor Survival in Patients with Chronic Lymphocytic Leukaemia
Authors: Pratt Guy , Mead Graham , Basu Supratik , Jacobs Abe , Holder Roger , Fegan Chris , Pepper Chris , Bradwell Arthur R. , Oscier David , Harding Stephen 
Published: April 2020

Abstract
Introduction: Serum free light chains (sFLC) have prognostic significance in plasma cell disorders. In B-cell chronic lymphocytic leukemia (CLL), a small study found 8/18 (44%) of patients to have abnormal FLC ratios but no assessment of prognostic value was published. The aim of the present study was to determine whether abnormal serum FLC concentrations are indicative of a poor prognosis in CLL patients.
Methods: Sera were analysed from 381 previously diagnosed CLL patients (Stage A 307; B 30; C 26; 18 missing; male: Female Ratio 1.6:1, mean age 71 (29–98)) with samples taken before their first treatment (303) or after treatment (78). The study was approved by the Birmingham Heart of England NHS Trust Review Board. Patients were described using the Binet staging system and measured for prognostic markers including CD38, Zap70, mutational status, β2M and FLC. Kaplan Meier survival curves and Cox proportional hazards regression (age, sex, CD38, Zap 70, mutational status, β2M and sFLC) were calculated using SPSS v14.
Results: 147/381 (39%) patient sera had abnormal sFLC ratios. Kaplan Meier analysis of all deaths showed abnormal ratios were significantly associated with worse survival (n=350, p&lt;0.001). Analysis of deaths attributed to CLL (n=30) also indicated that an abnormal FLC ratio was predictive of shorter survival (p=0.001). However, for deaths not attributed to CLL (n=32), the FLC ratio was not significantly predictive of outcome (p=0.112). For Cox regression analysis (n=228) of deaths attributed to CLL only, three significant, independent, prognostic factors were identified: CD38 (p&lt;0.001), abnormal ratio (p&lt;0.001) and Stage (p=0.027). Analysis of the untreated patient population (n=303), using Kaplan Meier analysis of time to first treatment, found that an abnormal lambda ratio (p=0.04) but not an abnormal kappa ratio (p=0.443) predicted earlier treatment. For patients with an abnormal lambda ratio, the mean time to first treatment was 38 months earlier than those patients with a normal ratio. Cox regression analysis (n=171) of time to first treatment, found 4 significant, independent factors predicting earlier treatment: Zap70 (p&lt;0.001), Age (p&lt;0.001), abnormal sFLC ratio (p=0.001) and Stage (p=0.027).
Conclusions: As shown in other monoclonal gammopathies, abnormal sFLC ratios were associated with poorer outcomes in patients with CLL. Furthermore, in an untreated population, patients with an abnormal lambda sFLC ratio required earlier treatment, indicating a pathological mechanism which is as yet unclear but which warrants further investigation.