bluuebunny/crossref_metadata_2025_split huggingface dataset:
Copper Deficiency Remains An Underappreciated Cause of Ineffective Hematopoiesis
Authors: Langston Amelia , Neely Jessica , Heffner Leonard , Griffith D. , Arellano Martha , Esper Gregory , McLemore Morgan L. , Ziegler Thomas , Kempton Christine , Sinha Rajni , Khoury H. Jean , Winton Elliott 
Published: April 2020

Abstract
Copper deficiency has long been recognized as cause of hematopoietic dysfunction, and diagnosis is straightforward if it is pursued. Over a three year period, we diagnosed copper deficiency in seven pts referred to our university-based hematology and BMT outpatient clinics for evaluation and treatment of myelodysplastic syndrome (MDS) or neutropenia/anemia. This represents approximately 3% of new outpatient referrals carrying an ICD-9 code corresponding to MDS or neutropenia. Patient characteristics are shown in Table 1. Three of the seven pts carried a presumptive diagnosis of MDS, and one had received several months of decitabine therapy. Two patients were actually referred for consideration of stem cell transplantation; the others were referred for evaluation of cytopenias. Six of the seven patients had been evaluated by a hematologist prior to referral. Only 3 of 7 pts in our series had recognized risk factors for copper deficiency such as prior gastric bypass or other GI dysfunction; postulated risk factors in the other pts are included in Table1. All pts in our series were anemic and leukopenic, with absolute neutropenia at presentation. In contrast, platelet counts were normal or elevated in all pts, consistent with most previous reports. Five of the seven pts in our series had neuropathy or myelopathy of variable severity. The hematologic abnormalities responded rapidly and completely to oral and/or IV copper replacement in all pts, although neurologic recovery was slow and incomplete.
Conclusions: Our experience indicates that copper deficiency is a relatively common cause of neutropenia and anemia, and the consequences of missing the diagnosis may be substantial, including performance of unnecessary transfusion, chemotherapy, and even stem cell transplantation. Normal or elevated platelet counts and concomitant neuropathy or myelopathy are important clues to the diagnosis. Furthermore, copper deficiency must be considered even in pts without obvious GI absorption abnormalities. Serum copper and ceruloplasmin assays should be incorporated into the routine evaluation of most pts with cytopenias and suspected MDS.
Age/gender Ref. diagnosis Risk factor Associated symptoms Serum copper (80–155 mcg/dl) Ceruloplasmin (21–53 mg/dl 53F MDS–RAEB unknown Severe sensory-motor neuropathy 29 7 43F MDS–RA Excess carbonated soda intake? Severe sensory-motor neuropathy 2 &lt;2 55F Anemia, neutropenia Gastricbypass sensory-motor neuropathy 4 3 45F Possible MDS Gastricbypass None 4 3 66F Anemia, neutropenia Excess tea intake? Bone pain 2 Link 56F Anemia, neutropenia Partial gastrectomy Severe sensory-motor neuropathy 2 &lt;2 36F Anemia, neutropenia Tetrathiomolybdate exposure (lubricants) Moderate sensory-motor neuropathy 1 2
BMI1 Interacts with FANCD2 at DNA Lesions and Prevents Chromosome Breaks
Authors: Chagraoui Jalila , Hebert Josee , Girard Simon , Sauvageau Guy 
Published: April 2020

Abstract
Bmi1 is a major determinant of hematopoietic stem cell (HSC) self-renewal. To date, much of our understanding of Bmi1 function comes from studies linking it to p16ink4a-Rb and p19arf-p53 pathways. However, several observations have raised the possibility that Bmi1 requirement for the maintenance of stem cell self-renewal ability extends far beyond its role in repressing the INK4a/ARF locus. The phenotypical similarities shared between Bmi1 deficiency in mouse and Fanconi Anemia (FA) patients (e.g., congenital aplastic anemia) together with the reported mono-ubiquitin ligase activities of proteins in both complexes and the emerging concept connecting DNA repair to stem cell properties, prompted us to evaluate Bmi1 implication in DNA damage repair. We now report that, like FA cells, Bmi1-deficient HSCs accumulate at G2/M phase of cell cycle. Moreover, Bmi1 is rapidly recruited to DNA damage foci in a PI3 kinase like kinase (PIKK)-dependant manner, in several cell types including hematopoietic stem cells. Upon induction of DNA lesions, Bmi1 interacts with several proteins involved in DNA damage response including γ-H2AX, MDC1, RAP80 and the monoubiquitinated form of FANCD2. We found that Bmi1 depletion did not hinder DNA damage-induced γ-H2AX foci formation and that RNF8-dependent signaling cascade is functional in absence of Bmi1. Furthermore, as observed in FA, loss of Bmi1 is associated with occurrence of spontaneous chromosome breaks and increased sensitivity to clastogenic agents. These chromosome breaks occur although FANCD2 monoubiquitination and loading onto chromatin is preserved. Together this work reveals an unsuspected role for Bmi1 in securing chromosome integrity and connects Polycomb genes to FA repair pathway.
Defective T Cell Migration in Chronic Lymphocytic Leukemia Is Repaired by Lenalidomide
Authors: Ramsay Alan G. , Svensson Lena , Hogg Nancy , Gribben John G. 
Published: April 2020

Abstract
We have previously demonstrated that multiple gene expression abnormalities are induced in T cells from chronic lymphocytic leukemia (CLL) patients including defects within the actin cytoskeleton signaling pathways that control immune recognition and motility (Gullu et al. JCI, 2005). T cell immune surveillance requires rapid migratory responses and LFA-1 (CD11a/CD18; αLβ2) is a promigratory receptor that engages the cytoskeleton to control migration. We hypothesized that CLL T cells may exhibit dysfunctional migration in response to ICAM-1, the principal ligand for LFA-1. Using time lapse microscopy, we observed significantly reduced chemokine SDF-1 (CXCL12) induced migration on ICAM-1 of CLL CD4 and CD8 T cells compared to age-matched healthy donor T cells. Healthy T cells tracked for 45 min displayed a random course of migration with an average speed of ~ 8 μm/min, whereas CLL T cells were slower ~ 5 μm/min (n=14, ~ 30% reduction, p&lt;0.01). We further postulated that direct contact of CLL tumor cells with healthy T cells would induce this migratory defect. Healthy CD4 or CD8 T cells were cocultured with either allogeneic CLL B cells or allogeneic healthy B cells and subsequently used in migration assays. Co-culture with CLL cells resulted in significantly reduced T cell migration compared with co-culture with healthy B cells (~ 44% reduction in migration, n=6, p&lt;0.01). Evidence that direct contact was required to induce this migratory defect was shown when no effect was observed when cell-cell adhesion was prevented by pretreatment of CLL cells with anti-ICAM-1 blocking antibody prior to primary co-culture with healthy T cells. This cancer-induced migratory defect was repaired when CLL T cells were pretreated with the immunomodulatory drug Lenalidomide (1μM for 1hr). Treatment with this agent enhanced the migratory potential of CLL T cells to a speed comparable to untreated and treated healthy T cells. The finding that lenalidomide can restore rapid migration in patient T cells provides evidence that this agent may increase immune surveillance in CLL patients.
Treatment with Lenalidomide (Revlimid®) Upregulates CD40 Expression on CLL Cells and Increases Their Sensitivity to CD40-Mediated Cytotoxicity in Vitro
Authors: Glezer Emilia , Ferrajoli Alessandra , Reuben James M. , Corral Laura G 
Published: April 2020

Abstract
Lenalidomide, an approved drug for the treatment of multiple myeloma and myelodysplastic syndromes with 5q deletion is currently undergoing clinical investigation in chronic lymphocytic leukemia (CLL). Although the exact mechanism of action of lenalidomide in CLL is not known, it was shown to augment anti-CD40 induced cytotoxicity in human multiple myeloma cells (Tai et al. Cancer Res. 2005) and is currently being evaluated in combination with an anti-CD40 agent in a multiple myeloma clinical trial. While signaling of the costimulatory receptor CD40 promotes survival, proliferation, and differentiation of normal B cells, it can cause activation-induced cell death in malignant B cells. In addition, ligation of CD40 by CD40L (CD154) was shown to sensitize B-CLL cells to apoptosis (Dicker et al. Blood 2006). In a phase II clinical study (Ferrajoli et al. Blood 2008), blood samples from 12 CLL patients were collected at baseline and after 1 week, 4 weeks, 3 months and 6 months of treatment with lenalidomide. Samples were shipped overnight to (San Diego) for the phenotypic monitoring of CD40 expression on CD19+CD5+ B-CLL cells by flow cytometry. Changes in CD40 expression were also measured in B-CLL cells treated in vitro with lenalidomide. In addition, samples were used for in vitro cytotoxicity assays that included treatment with fludarabine or valproic acid in combination with lenalidomide; and a CD40-induced cytotoxicity assay using CD40 Ligand (CD154)-transfected murine fibroblasts and lenalidomide. In 6 out of 12 patients, lenalidomide therapy significantly upregulated the expression of CD40 on B-CLL cells above pretreatment levels (4.5±4.5% vs. 49.5±32.7 %, p=0.020). Moreover, B-CLL cells obtained at baseline from 6 patients and treated in vitro with 1 μM of lenalidomide (a concentration corresponding to clinically achievable plasma levels) for 24h and/or 48h exhibited significantly higher expression of CD40 than B-CLL cells exposed to DMSO vehicle (1.95±0.23 fold increase; p=0.038). Exposure to lenalidomide in vitro neither caused apoptosis of B-CLL cells nor increased their sensitivity to fludarabine or valproic acid cytotoxicity (n=9). However, when B-CLL cells obtained at baseline from 6 patients were treated in vitro with lenalidomide, they became more sensitive to apoptosis induced by CD40 Ligand (CD154)-transfected murine fibroblasts than DMSO treated cells (62.6±16.8% lenalidomide vs. 43.2±16.1% DMSO; p=0.032). Lenalidomide had no significant effect on the viability of B-CLL cells co-cultured with control non-transfected murine fibroblasts. Our data suggest a potential therapeutic use of lenalidomide in combination with CD40 ligation in CLL and warrant further investigation.
Richter Transformation of Chronic Lymphocytic Leukemia: Incidence, Risk Factors and Outcome
Authors: Alipour Sina , Leitch Heather , Vickars Linda M , Foltz Lynda M , Galbraith Paul F , Leger Chantal S , Ramadan Khaled M 
Published: April 2020

Abstract
Richter transformation (RT) is a rare complication of chronic lymphocytic leukemia (CLL). There is little information in the literature about its risk and outcome. In this study we assessed the incidence, presenting characteristics and outcomes of patients (pts) with CLL who developed RT. 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, 24 pts (5%) developed RT. Presenting features included B-symptoms (17%), lymph node enlargement (58%), progressive cytopenia (29%), hypercalcemia (4%), and spleno/hematomegaly (13%). The median age at diagnosis of CLL and RT were 64 y (range 33–80 y) and 67 y (range 48–81 y) respectively. The median time to transformation from CLL diagnosis was 61 months (range 1–257 m). Twenty one patients (88%) had been previously treated for CLL. Seventeen patients (71%) had received &gt;1 prior therapy. The median lymphocyte count at diagnosis was 12 ×109/L (range 4–120 ×109/L). Six patients (25%) are still alive with a median follow up of 38 m (range: 3–66 m). The only predictive factor for better survival post-transformation on univariate analysis was age of less than 60 y at CLL diagnosis (p=0.01). Other factors such as CLL Rai stage, lymphocyte count at diagnosis were not predictive for survival. This group of patients was compared with randomly selected group of patients with CLL but did not have RT. The baseline characteristics of the groups are presented in the table. No significant differences were found between the two groups in terms of gender, age at diagnosis, Rai stage or median lymphocyte count at diagnosis. The 5 and 10 year OS for the RT group were 76% and 39% compared to 93% and 84% for the CLL group (p= 0.002), respectively. In summary, RT significantly shortens the survival of CLL patients. There were no obvious predictive factors for RT in CLL pts at diagnosis.
Table: Baseline characteristics of Richter and CLL groups.
Parameter Richter group (%) CLL group (%) P value Number 24 37 Sex: M/F (ratio) 16/8 (2:1) 22/15 (1.5:1) 0.052 Age at Diagnosis: Median (range) 64 (33–80) 60 (37–85) 0.6 Rai stage at diagnosis: 0, 1+2, 3+4 7, 16,1 (29, 67, 4) 23, 14, 0 (62, 38, 0) 0.3 Median lymphocyte count at diagnosis (range) 12 ×109/1 (4–120) 8 × 109/1 (5–394) 0.056
Fig: OS of pts with RT compared with CLL pts and no RT Fig:. OS of pts with RT compared with CLL pts and no RT
The RALGEF Pathway Contributes to the Pathogenesis of Chronic Myelogenous Leukemia by BCR/ABL
Authors: Fredericks Jessica , Parikh Chaitali , Subrahmanyam Ramesh , Ren Ruibao 
Published: April 2020

Abstract
Selected inhibitors of the BCR/ABL tyrosine kinase have shown a remarkable clinical activity in patients with chronic myelogenous leukemia (CML). However, these drugs do not completely eradicate leukemic cells and drug resistance emerges. Identification of additional contributors to the pathogenesis of CML remains to be important for developing strategies for overcoming resistance to BCR/ABL kinase inhibitors and for eradicating leukemic cells. We and others have previously shown that expression of BCR/ABL in mouse bone marrow cells by retroviral transduction and transplantation (BMT) efficiently induces a CML-like myeloproliferative disorder (MPD). Using this BMT model for CML, we have found that the Grb2 SH2 binding site Y177 of BCR/ABL, which is critical for BCR/ABL to activate the RAS pathway, is required for the induction of CML-like disease by BCR/ABL. We have further shown that oncogenic NRAS (NRASG12D) can rescue the defect of the Y177F mutant BCR/ABL in the induction of CML-like disease. To further elucidate the pathways downstream of NRAS responsible for this “rescue” effect, we utilized three well-characterized NRAS effector mutants, G12D/T35S (activating RAF but is impaired in binding PI3K and RALGEF), G12D/E37G (activating RALGEF but not RAF or PI3K), and G12D/Y40C (activating PI3K but not RAF or RALGEF). None of the three NRAS effector mutants could induce hematological malignancies by themselves, but all were capable of “rescuing” the CML defect of BCR/ABLY177F to some extent. Interestingly, the NRAS G12D/E37G effector mutant was the most efficient. We further examined the role of RALGEF pathway by introducing an activated RALGDSCAAX into our BCR/ABLY177F mouse model. RALGDS-CAAX was able to cooperate with BCR/ABLY177F to induce a CML-like MPD in nearly half of mice whereas RALGDSCAAX alone did not induce diseases in any mice. As a complement to this study, we also introduced dominant negative RAL A or RAL B in the background of BCR/ABL. This resulted in a significant delay in disease onset. Taken together, this data sheds light on the importance of the RALGEF pathway in BCR/ABL-mediated CML induction and supports the notion of inhibition of this pathway as a potential therapeutic strategy.
Combination Therapy of Small Molecule Inhibitor PHA-739358 and Tyrosine Kinase Inhibitor Imatinib Yields Synergistic Antiproliferative Effects and Suppresses Emergence of Resistance of Chronic Myeloid Leukemia in Vitro
Authors: Balabanov Stefan , Gontarewicz Artur , Keller Gunhild , Moll Jürgen , Bokemeyer Carsten , Holyoake Tessa L , Brummendorf Tim H. 
Published: April 2020

Abstract
The success story of Imatinib (IM) in chronic myeloid leukemia (CML) is comprised by primary or acquired resistance to IM, insufficient therapeutic options for advanced stages of disease and limited effects on immature hematopoietic stem cells emphasizing the need for novel therapeutic strategies. We recently reported on PHA-739358, which shares activity of a pan-Aurora and an ABL kinase inhibitor. In this study, the individual contribution of both pathways to the effect of PHA-739358 was further investigated and a dose dependent reduction of BCR-ABL activity starting at very low concentrations was observed. In contrast, inhibition of the phosphorylation of Aurora kinase down stream target phospho-histone H3-Ser10 required higher amount of the inhibitor suggesting a predominant BCR-ABL mediated effect of PHA-739358 at low concentration. Simultaneous short-term treatment with PHA-739358 and IM resulted in pronounced apoptosis of wild type or low-grade IM-resistant BCR-ABL expressing cells while no such effects were observed in BCR-ABL negative or highly IM-resistant T315I mutants. In primary CD34+ cells of CML patients including non-dividing quiescent leukemic stem cells combination therapy with IM and PHA-739358 revealed a synergistic antiproliferativ activity which also affected immature CD34+38-cells. However, neither mono- nor combination therapy led to a significant induction of apoptosis. In addition, PHA-739358 did not influence quiescent stem cells analysed in the CSFE assays. Another focus of interest was the emergence of resistance secondary to treatment with PHA-739358, where resistant clones were found considerably less frequent than in IM-treated cells. Interestingly, PHA-739358 resistant cells did not reveal mutations in Aurora kinases A and B or in BCR-ABL kinase domain and remained IM-sensitive. Furthermore, simultaneous administration of PHA-739358 and IM considerably reduced the number of resistant clones and virtually abolished emergence of resistance at 2-times IC50 concentration of PHA- 739358 (plus IM at IC50). In conclusion, PHA-739358 potently inhibits proliferation of CD34+ stem und progenitor cells including immature CD38- subpopulation. However, in line with other tyrosine kinase inhibitors no induction of apoptosis in quiescent stem cells can be achieved. Remarkably, combination of PHA-739358 and IM prevents emergence of resistance rising the hope for a durable control of CML.
Patients with Chronic Myeloid Leukemia with Variant Philadelphia Chromosome (Ph) Translocations Have a Similar Outcome as Those with Classic Ph When Treated with Imatinib or 2nd Generation TKI
Authors: Batty Nicolas , Kantarjian Hagop , Borthakur Gautam , Ravandi Farhad , O’Brien Susan , Estrov Zeev , Shan Jianqin , Verstovsek Srdan , Cortes Jorge 
Published: April 2020

Abstract
Background: Variant Philadelphia chromosome (Ph) translocations frequently involving 1-2 additional chromosomes besides 9 and 22 and represent 5–10% of patients (pts) with chronic myeloid leukemia (CML). The European LeukemiaNet recommendations provide a warning for patients with variant translocations, although there is limited information about their outcome after therapy with tyrosine kinase inhibitors (TKI). Our prior analysis mostly among pts who had failed prior interferon suggested that these pts had similar outcome to those with classic Ph translocations when treated with imatinib (El-Zimaity et al; Br. J Haematol 2004).
Aims: To explore the characteristics and outcome of patients with variant translocations treated with frontline imatinib or 2nd generation TKI (dasatinib or nilotinib) after imatinib failure.
Methods: We reviewed the outcome of all pts with CML treated at our institution in 3 groups:
early chronic phase (CP) receiving imatinib as initial therapy, and CP treated with 2nd generation TKI after Imatinib failure, accelerated phase (AP) treated with 2nd TKI after imatinib failure.
Results of pts with variant Ph were compared to those with classic Ph.
Results: Among 554 pts (278 CP frontline imatinib, 190 CP post imatinib failure, 86 AP post Imatinib failure) 33 (6%) had variant Ph (21[8%], 6[3%], 6[7%], in each of the 3 groups, respectively). Median follow up is 55 months (mo) (2 – 90), 24 (1 – 53) mo and 29 (5 – 46) mo, respectively, for the 3 groups. Results are summarized in the following tables:
Frontline Imatinib Therapy Percentage Variant Ph Classic Ph P value N=21 N=255 MCyR 95 95 1 CCyR 86 89 0.49 2-yr EFS 83 93 0.93 2-yr TFS 94 96 0.7 2-yr OS 100 99 0.48 Second generation TKI Variant Ph Chromosome Variant Ph Classic Ph P value Chronic Phase N = 6 N = 78 MCyR 100 75 0.34 CCyR 100 72 0.34 2-yr EFS 100 80 0.27 2-yr OS 100 98 0.71 Accelerated Phase N=6 N=80 MCyR 33 38 1 CCyR 33 32 1 2-yr EFS 25 41 0.41 2-yr OS 100 89 0.44
Conclusion: Pts with variant Ph have a similar prognosis to those with classic Ph translocations when treated with imatinib as initial therapy or with 2nd generation TKI after imatinib failure. The warning category for these patients may no longer be needed in the era of TKI.
Imatinib Induced Molecular Response in CD34+ Hematopoietic Stem and Progenitor Cells of Patients with Chronic Myeloid Leukemia Following the First Week of Therapy
Authors: Bruennert Daniela , Czibere Akos , Bruns Ingmar , Pechtel Sabrina , Gattermann Norbert , Kronenwett Ralf , Haas Rainer , Frank Neumann 
Published: April 2020

Abstract
Imatinib is a selective bcr-abl tyrosine-kinase inhibitor, successfully used as standard therapy for patients with chronic myelogenous leukemia (CML) in chronic phase. We examined the effect of Imatinib on the gene expression transcriptome pattern of CD34 positive hematopoietic stem and progenitor cells of 6 patients with newly diagnosed CML following the first week of therapy. Affymetrix U133A 2.0 microarrays covering 21.722 probe sets were used to analyze and compare the gene expression profiles of CD34+ cells from peripheral blood of 6 patients with newly diagnosed CML in chronic phase before and 7 days after the initiation of Imatinib first line therapy. One patient was female and 5 male. Their median age was 61 years (range 32–79 years). In addition, quantitative molecular monitoring of bcr-abl was performed using Light Cycler technology. Using a supervised hierarchical cluster analysis of the gene expression data we found that 303 genes were differentially expressed with a lower bound of at least 1.2 fold (−2.58 to −1.2 and 1.2 to 2.09). Of these, 183 genes were down-regulated and 120 genes were up-regulated comparing day 1 with day 7. A considerable number of the down-regulated genes are involved in the regulation of cell cycle (CDC2, CDC20, CCNB1, CCNB2) and DNA replication (TOP2A, POLE2, MCM-complex). In contrast, genes coding for proteins governing adhesion and cell migration were up-regulated (CD44, L-Selectin). The observations of the gene expression data of the aforementioned genes could be confirmed by quantitative real-time PCR. After 10 months of Imatinib therapy (range 6–13 months) all 6 patients reached in median a 3 log reduction (range 1.5–3 log reduction) of their bcr-abl mRNA. Bcr-abl FISH analysis confirmed that the majority of CD34+ cells examined were Ph-Chromosome positive. These data indicate that in the early phase of treatment Imatinib mainly acts as an inhibitor of cell cycle and replication which results in a decreased proliferation. The silencing of the Ph-Chromosome positive cells is associated with an up-regulation of genes coding for adhesion during the first week of therapy.