bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reporting of Randomised Controlled Trials in Hodgkin’s Lymphoma from 1966 to 2002. A Pre- and after CONSORT Evaluation.
Authors: Kober Thilo , Trelle Sven , Greb Alex , Skoetz Nicole , Engert Andreas 
Published: April 2020

Abstract
Introduction/Background: Health professionals base treatment decisions primarily on scientific findings in the medical literature. Randomised controlled trials (RCTs) are considered the best tool to evaluate the applicability of clinical research but there is overwhelming evidence to indicate that the quality of reporting RCTs is less than optimal. The Consolidated Standards for Reporting Trials (CONSORT) statement was developed to help to improve the quality of reports of RCTs and published in 1996.
Methods and Material: Retrospective survey of reports of RCTs in Hodgkin’s lymphoma published in English and German between 1966 and 2002. Evaluation tool was a 14-item questionnaire based on the validated CONSORT checklist. Statistical analysis was performed by chi-square method and Fisher’s exact test where appropriate.
Results: The analysis of 243 published full-text articles in 59 journals from early 1966 to the end of 2002 indicates an improvement in the quality of reporting RCTs after CONSORT but this enrichment is not consistent. A highly significant enhancement post CONSORT was observed in 5 out of 14 reporting items (i.e. 35.7%; description of statistics methods, reporting of power calculation, ITT analysis, primary outcomes and 95% confidence interval (P=&lt;.0005 – .002)). A sixth reporting item (adverse events) achieved borderline significance (P=.055). Intention-to-treat was explicitly mentioned in 11.9% (29/243), summary results for each comparative group was 98.4% (239/243) and precision of estimated effect size (95% confidence interval) were provided in 21.8% (53/243) respectively. Adverse events were reported in 77% (187/243), and conflict of interest was declared in 4.5% (11/243). Deviations in the reported versus performed randomised allocation in a subset of reports specifically mentioning ITT analysis (n=29) ranged from 2.5%–15%.
Conclusions: Despite years of educational efforts, reporting of randomised clinical trials for Hodgkin’s lymphoma in the scientific literature remains unsatisfactory and requires further concerted action by publishers, journal editors, learned societies and medical schools.
IL-31 Receptor and IL-31 in the Positive Regulation of Myeloid Progenitor Cell Proliferation/Survival.
Authors: Broxmeyer Hal E. , Ghilardi Nico , Hangoc Giao , Cooper Scott , Tao Wen , Mantel Charlie , Graham-Evans Barbara , deSauvage Frederic J. 
Published: April 2020

Abstract
Interleukin (IL)-31 receptor (R), also called gp130-like monocyte-receptor (GLM-R; Ghilardi et al. J. Biol. Chem.277:16831, 2002) is related to gp130 (~25% homology), and G-CSF-R (~24%). Its signaling activates STAT3 and STAT5. IL-31 is a four helix bundle cytokine preferentially produced by T helper 2 cells. Nothing is known of the possible hematopoietic effects of IL-31R and IL-31. However, since: IL-31 signals through a receptor composed of IL-31RA and Oncostatin M R (Dillon et al. Nature Immunol. 5:752,2004), Oncostatin M is implicated in homeostasis of myeloid progenitor cells (Broxmeyer et al. Immunity.16:815, 2002), and STAT3 and 5 are implicated by a number of groups in cytokine regulation of hematopoiesis, we hypothesized that the IL-31/IL-31R axis would be involved in regulation of hematopoiesis. We first compared myeloid progenitor cell (MPC: CFU-GM, BFU-E, and CFU-GEMM) numbers and cycling status in marrow and spleen of IL-31R −/− vs. littermate control mice (+/+) using a combination of Epo, SCF and PWMSCM to stimulate in vitro the cells taken from these mice. IL-31R −/− mice had significantly decreased numbers of MPC per femur (~51%) and spleen (~36–45%) with significantly decreased MPC cycling status in marrow (% MPC in S-phase: 0–3% in IL-31R −/− vs. 41–53% in +/+ mice). MPC in spleen of IL-31 −/− and +/+ were both in a slow or non cycling state (0–3% in S-phase). In contrast to CFU-GM from +/+ mice, CFU-GM from IL-31R −/− mice demonstrated little or no synergistic response to combined stimulation in vitro with GM-CSF or IL-3 with either SCF or Flt3-ligand (FL). This translated to decreased absolute numbers per femur of GM-CSF+SCF-, GM-CSF+FL-, IL-3+SCF-, and IL-3+FL- responsive CFU-GM in IL-31R −/− mice. However, there were no significant differences between GM-CSF- or IL-3- responsive CFU-GM per femur between IL-31R −/− vs. +/+ mice suggesting effects on immature subsets of MPC. Recombinant IL-31 was assessed for effects in vitro. IL-31, at concentrations up to 100ng/ml, did not stimulate colony formation by marrow MPC, nor did it enhance or suppress colony formation stimulated by GM-CSF, Epo, Epo+SCF, or Epo+SCF+GM-CSF. However, IL-31 did enhance survival of MPC subjected to delayed growth factor addition in a manner similar to, but not as potent as, that of SDF-1/CXCL12. IL-31 manifested no chemotaxis activity for +/+ MPC, and IL-31R −/− and +/+ MPC were equally responsive to the chemotactic effects of SDF-1/CXCL12. These results suggest that the IL-31R in vivo acts to positively regulate numbers and cycling of immature subsets of MPC in the marrow, and that IL-31 has survival enhancing effects on MPC in vitro.
Cell Cycle Regulation and Cell Fate Decisions in Hematopoietic Stem Cells.
Authors: Passegue Emmanuelle , Wagers Amy J. , Giuriato Sylvie , Anderson Wade C. , Weissman Irving L. 
Published: April 2020

Abstract
The blood is a perpetually renewing tissue seeded by a rare population of adult bone marrow hematopoietic stem cells (HSC). During steady-state hematopoiesis, the HSC population is relatively quiescent but constantly maintains a low numbers of cycling cells that differentiate to produce the various lineage of mature blood cells. However, in response to hematological stress, the entire HSC population can be recruited into cycle to self-renew and regenerate the blood-forming system. HSC proliferation is therefore highly adaptative and requires appropriate regulation of cell cycle progression to drive both differentiation-associated and self-renewal-associated proliferation, without depletion of the stem cell pool. Although the molecular events controlling HSC proliferation are still poorly understood, they are likely determined, at least in part, by regulated expression and/or function of components and regulators of the cell cycle machinery.
Here, we demonstrate that the long-term self-renewing HSC (defined as Lin−/c-Kit+/Sca-1+/Thy1.1int/Flk2−) exists in two distinct states that are both equally important for their in vivo functions as stem cells: a numerically dominant quiescent state, which is critical for HSC function in hematopoietic reconstitution; and a proliferative state, which represents almost a fourth of this population and is essential for HSC functions in differentiation and self-renewal. We show that when HSC exit quiescence and enter G1 as a prelude to cell division, at least two critical events occur: first, during the G1 and subsequent S-G2/M phases, they temporarily lose efficient in vivo engraftment activity, while retaining in vitro differentiation potential; and second, they select the particular cell cycle proteins that are associated with specific developmental outcomes (self-renewal vs. differentiation) and developmental fates (myeloid vs. lymphoid). Together, these findings provide a direct link between HSC proliferation, cell cycle regulation and cell fate decisions that have critical implications for both the therapeutic use of HSC and the understanding of leukemic transformation.
Cyclin D3 Is Required for Peritoneal B-1a Lymphocyte Proliferation.
Authors: Mataraza Jennifer M. , Tumang Joseph R. , Rothstein Thomas L. , Chiles Thomas C. 
Published: April 2020

Abstract
Cyclins D2 and D3 are coordinately induced in response to mitogenic stimulation of splenic B-2 lymphocytes. It is recognized that the cyclin D2:cdk4:pRb pathway plays an essential role in B-2 cell proliferation. By contrast, little is known about the function of cyclin D3 in B cells. Peritoneal CD5+ B-1 cells represent a distinct subset of B lymphocytes and exhibit several unique phenotypic and functional characteristics, which distinguish them from B-2 cells. B-1 cells are associated with several human disease states characterized by B-cell expansion. Notably, B-1 cells represent the normal counterpart for a subset of human chronic lymphocytic leukemia (CLL), the cells of which express CD5. In mice, monoclonal expansions of CD5+ B-1 cells, that resemble CLL, develop as a function of age. These associations with malignant diseases impel the necessity to understand cell cycle control in B-1 cells. In contrast to splenic B-2 cells, stimulation of ex vivo B-1 cells results in an early and transient induction of cyclin D2; however, cyclin D2 complexes account for a relatively minor amount of the total pRb phosphorylation. Evidence for a second cyclin functioning in this capacity is supported by the finding that stimulated cdk4/6-mediated phosphorylation of pRb increases dramatically in mid-to-late G1-phase coincident with the induction of cyclin D3. Thus, in contrast to B-2 cells, the non-overlapping expression of cyclins D2 and D3 points to distinct roles for these D-type cyclins in B-1 cells. We hypothesize that the timing and duration of cyclin D3 induction suggest a unique role in mediating the G1/S transition in B-1 cells. To investigate this possibility, we transduced TAT-p16 peptidyl mimetics into ex vivo B-1 cells immediately prior to cyclin D3 induction to specifically target and inactivate cyclin D3-cdk complexes. We report here that transduction of TAT-p16 mimetics selectively disrupted cyclin D3-cdk4 complexes, whereas cdk2-containing complexes remained intact. Transduction of wild-type TAT-p16 mimetics, but not mutant TAT-p16 mimetics blocked S-phase entry in response to several B-cell mitogens. In addition, we found that transduction of TAT-p16 peptidyl mimetics inhibited pRb phosphorylation by D-type cyclin-cdk4/6 holoenzymes in B-1 cells stimulated with PMA, LPS or CD40L. These results provide the first evidence of a subset-specific functional role for cyclin D3 in B cells and suggest that cyclin D3, in its capacity as a regulator of cdk4/6-mediated pRb phosphorylation, is required for B-1 cell proliferation.
CUL-4A Targets p27 for Degradation and Regulates Proliferation, Cell Cycle Exit, and Differentiation during Erythropoiesis.
Authors: Chun Kristin T. , Jia Nan , Naaldjik Yahaira M. , Kapur Reuben , Li Binghui 
Published: April 2020

Abstract
As erythroid progenitors differentiate into precursors and finally mature red blood cells, they induce the expression of lineage-specific genes, and their proliferation declines until cell cycle exit. CUL-4A encodes a core subunit of a ubiquitin ligase that targets proteins for ubiquitin-mediated degradation, and CUL-4A haploinsufficient mice display hematopoietic dysregulation with fewer multipotential and erythroid committed progenitors (3-fold and 5-fold, respectively). In this study, stress induced by 5-fluorouracil or phenylhydrazine reveals a delay in the ability of CUL-4A +/− mice to recover erythroid progenitors and precursors and to reestablish normal hematocrits. Conversely, over-expression of CUL-4A in a growth factor-dependent, proerythroblast cell line increases proliferation 34% (tritiated thymidine incorporation) and the proportion of cells in S-phase 5%. When these cells are induced to terminally differentiate, endogenous CUL-4A protein expression declines 3.6-fold. Its enforced expression interferes with erythrocyte maturation (beta-globin induction) and cell cycle exit, and instead promotes proliferation. Furthermore, p27 accumulates during erythroid terminal differentiation, but CUL-4A enforced expression increases p27 protein turnover nearly 7-fold and attenuates its accumulation. CUL-4A and p27 proteins co-immunoprecipitate, indicating that a Cul-4A ubiquitin ligase targets p27 for degradation. These findings suggest that a Cul-4A ubiquitin ligase positively regulates proliferation by targeting p27 for degradation and that CUL-4A down-regulation during erythroid terminal differentiation allows p27 to accumulate and signal cell cycle exit.
Induction of Hematopoietic Stem Cell Senescence by Ionizing Radiation.
Authors: Wang Yong , Schulte Bradley A. , LaRue Amanda C. , Ogawa Makio , Zhou Daohong 
Published: April 2020

Abstract
Exposure to ionizing radiation (IR) and certain chemotherapeutic agents not only causes acute bone marrow (BM) suppression but also leads to long-term residual hematopoietic injury. This later effect has been attributed to the damage to hematopoietic stem cell (HSC) self-renewal. Using a mouse model, we investigated whether IR induces senescence in HSCs, as induction of HSC senescence can lead to the impairment of HSC self-renewal. The results showed that exposure of C57BL/6 mice to a sublethal dose (6.5 Gy) of total body irradiation (TBI) resulted in a long-lasting quantitative and qualitative reduction in HSCs (Lin− c-kit+ Sca-1+ or LKS+ cells). Compared to control HSCs, HSCs from irradiated BM at 4 weeks after TBI exhibited a significant reduction in day-35 CAFC frequency and deficiency in cell proliferation and colony formation in a single cell culture assay stimulated with SCF/TPO and SCF/TPO/IL-3, respectively. In addition, transplantation of irradiated HSCs (500 LKS+ cells/recipient) produced less than 1% long-term (2-month) engraftment in a competitive repopulation assay while transplantation of the same number of control HSCs resulted in 24.8% engraftment. Furthermore, HSCs from irradiated mice expressed increased levels of p16Ink4a and senescence-associated beta-galactosidase (SA-beta-gal), two commonly used biomarkers of cellular senescence. In contrast, hematopoietic progenitor cells (Lin− c-kit+ Sca-1− or LKS− cells) from irradiated mice did not show significant changes in clonogenesity in a CFU assay and expressed minimal levels of p16Ink4a and SA-beta-gal. These results suggest that exposure to IR can induce senescence selectively in HSCs but not in HPCs. Interestingly, this IR- induced HSC senescence was associated with a prolonged elevation of p21Cip1/Waf1, p16Ink4a and p19ARF mRNA expression, whereas the expression of p27Kip1, p18Ink4c and p19 Ink4d mRNA was not increased. This suggests that p21Cip1/Waf1, p16Ink4a and p19ARF may play an important role in IR-induced senescence in HSCs, since their expression has been implicated in the initiation, establishment and maintenance of cellular senescence. Therefore, these findings provide valuable insights into the mechanisms underlying IR-induced long-term BM damage. This could lead to the discovery of novel molecular targets for intervention to circumvent IR-induced BM toxicity. In addition, understanding how normal HSCs senesce after IR and chemotherapy will help us to elucidate the molecular mechanisms whereby leukemia/cancer stem cells evade these cancer treatments and provide better knowledge of organismal aging.
Bad Phosphorylation Is Reduced in Response to Inhibition of Constitutively Activated FLT3.
Authors: Kim Kyu-Tae , Levis Mark , Small Donald 
Published: April 2020

Abstract
Constitutively activating internal tandem duplication (ITD) mutations of the receptor tyrosine kinase FLT3 play an important role in leukemogenesis and their presence is associated with poor prognosis in acute myeloid leukemia (AML). Previously we showed that human leukemia-derived myeloid cell lines having constitutive activation of FLT3 undergo apoptotic cell death when treated with FLT3 inhibitors. Examining the anti- and pro-apoptotic proteins in constitutively activated FLT3 signaling in BaF3/ITD, MOLM-14 and MV4-11 cell lines, we found that the level of Bad phosphorylation was greatly decreased by FLT3 inhibitor treatment. Bad is a proapoptotic member of the Bcl-2 family that can displace Bax from binding to Bcl-2 and Bcl-xL, resulting in cell death. Survival factors such as IL-3 inhibit the apoptotic activity of Bad by activating intracellular signaling pathways that result in the phosphorylation of Bad at Ser112 and Ser136. Both Ser112 and Ser136 are rapidly dephosphorylated after treatment with FLT3 inhibitors in BaF3/ITD, MOLM-14, and MV4-11 cells. We also found Bad to be highly phosphorylated in both wild-type and mutant FLT3 primary AML samples. In confirmation of the cell line data, Bad was rapidly dephosphorylated after treatment of the primary samples with lestaurtinib (CEP-701). Upstream molecules responsible for phosphorylation of Bad include Akt, Erk/MAPK, Pim-1, and Pim-2. We previously reported Pim-1 as one of the genes whose expression is induced by constitutively activated FLT3. We and other groups have also shown that constitutively activated FLT3 induces multiple signaling pathways, including PI3/Akt, Erk/MAPK, and Jak/STAT. The dephosphorylation of Bad in response to FLT3 inhibition also correlates with deactivation of Stat5, MEK1/2 and Akt kinase activities and decreased expression of Pim-1. Thus, Bad may be one of the points that these multiple signaling pathways converge in FLT3-mediated cell survival. Thus, it appears that activated FLT3 phosphorylates Bad, resulting in the inability of Bad to bind to Bcl-xL, therefore blocking apoptosis. This is the first report of deactivation of a pro-apoptotic Bcl-2 family member induced by constitutively activated FLT3.
Stem Cell Mobilization and Egress of AML Blasts from the Bone Marrow Are Both Regulated by MT-MMP-Mediated Activation of MMP-2.
Authors: Marquez-Curtis Leah A. , Shirvaikar Neeta , Larratt Loree M. , Turner A. Robert , Ratajczak Mariusz Z. , Janowska-Wieczorek Anna 
Published: April 2020

Abstract
The cell-surface proteolytic enzymes membrane-type (MT)-matrix metalloproteinases (MMPs) activate secreted latent forms of MMPs and play a key role in cell migration and tumor cell invasion and metastasis. Previously we reported that mobilized peripheral blood (mPB) CD34+ cells as well as AML blasts secrete inactive (pro)MMP-2, in contrast to normal steady-state bone marrow (BM) CD34+ cells which do not. In this study we hypothesized that the egress from BM of normal hematopoietic stem/progenitor cells during G-CSF-induced mobilization or of AML blasts shares a common mechanism that involves activation of secreted proMMP-2 by MT-MMPs. We evaluated the expression of MT-MMPs (MT1-MMP, MT2-, MT3- MT4-, MT5-, MT6-) in normal and leukemic hematopoietic cells, as well as in BM stromal cells, and determined their role in proMMP-2 activation and migration. We found MT1-MMP expression (mRNA and protein) in mPB CD34+ cells and in the majority of AML samples (from 21 out of 26 patients) and upregulation of MT1-MMP by G-CSF in steady-state BM CD34+ cells. Moreover, we confirmed the secretion of proMMP-2 in media conditioned by hematopoietic (mPB CD34+, AML) cells and stromal cells. However, we detected the active form of MMP-2 in co-cultures of the hematopoietic (mPB CD34+, AML) cells with stromal cells, as well as in co-cultures of steady-state BM CD34+ cells stimulated with G-CSF with stroma. In cultures of stromal cells alone G-CSF had no effect on the expression of either MT1-MMP or MMP-2. To evaluate the role of MT-MMPs in proMMP activation, we examined the leukemic KG-1 cell line, which we found not to express any MT-MMPs, and did not detect active MMP-2 in co-cultures with stroma. On the other hand, primary AML samples that did not express MT1-MMP but expressed MT2-, MT4- or MT5-MMPs activated proMMP-2 in co-cultures with stroma. Moreover, the MT1-MMP inhibitor epigallocatechin-3-gallate significantly reduced trans-Matrigel migration of mPB CD34+ (by 50%) and AML cells (by 70–90%). Hence we suggest that in the BM microenvironment (i) MT1-MMP localized on the surface of hematopoietic cells activates MMP-2, inducing a highly proteolytic microenvironment, and (ii) MT1-MMP upregulation by G-CSF in BM CD34+ cells can result in CD34+ cell mobilization from BM. Similarly, the constitutive high expression of MT1-MMP and other MT-MMPs in AML blasts also contributes to MMP-2 activation in the BM microenvironment and may be conducive to the egress of AML blasts from the BM.
Inhibitory and Proliferation-Inducing Effects of Valproic Acid on Leukemic Stem Cells from Different Acute Myeloid Leukemias.
Authors: Bug Gesine , Zheng Xiaomin , Schoch Claudia , Ruster Brigitte , Schwarz Kerstin , Kampfmann Manuela , Hoelzer Dieter , Ottmann Oliver G. , Henschler Reinhard , Ruthardt Martin 
Published: April 2020

Abstract
The antileukemic activity of the histone deacetylase inhibitor valproic acid (VPA) in combination with all-trans retinoic acid and/or low-dose chemotherapy is currently evaluated in clinical trials for the treatment of acute myeloid leukemia (AML). Preliminary data demonstrate that only a small subset of patients responded to these VPA-containing regimens and none of them achieved a molecular remission (Bug et al., Cancer 2005, in press). Recently, it has been shown that the in vitro exposure of normal hematopoietic stem cells (HSC) to VPA significantly increases their proliferation and self-renewal potential. Given the fact that normal and leukemic stem cells are believed to share regulatory mechanisms of proliferation and self-renewal, we investigated whether VPA can also stimulate leukemic stem cells.
First we confirmed the expansion of normal HSC in vivo by treating C57BL/6J mice with VPA for two days. Here we report that orally administered VPA led toa significant increase in the cellularity of both bone marrow (BM) and spleen;a significant increase of Sca1+/c-Kit+ cell numbers in BM and spleen;a slight splenomegaly (0.11–0.42 g vs. 0.06–0.08 g in control mice);a significant acceleration of cell cycle progression in spleen cells.
Next we exposed highly enriched CD34+/CD38− cells (average purity of 84.2+/−1.6%) from the peripheral blood of 6 consecutive AML patients at first diagnosis to VPA (100 μg/ml) in presence of SCF, FL, TPO and IL-3 in liquid culture as well as in colony forming unit (CFU) assay. Chromosomal aberrations were detected in 5 out of 6 AML samples. Here we show that i.) the exposure to VPA inhibited differentiation and maintained a higher level of CD34+/CD38− cells in liquid culture at day 7 and 14 as compared to untreated controls in all samples; ii.) the majority of CD34+ cells were of leukemic origin as revealed by fluorescence in situ hybridization (FISH) analysis of 4 out of 5 AML samples with chromosomal aberrations; iii.) in one t(8;21)-positive AML sample VPA reduced the proportion of leukemic CD34+ cells to 60% and 17% on day 7 and 14, respectively, as compared to controls (92% and 86%); iv.) in one trisomy 8-positive AML sample VPA induced expansion of leukemic CD34+ cells; v.) the exposure to VPA did not only increase the number of CFUs, but also the cellularity of single colonies which exhibited an immature morphology and whose leukemic origin was confirmed by FISH analysis of one AML sample.
In conclusion, VPA was shown to have differential effects on CD34+/CD38- cells from untreated AML patients ranging from a selective inhibition of t(8;21)-positive cells, over a stabilization of the leukemic stem cell compartment, up to the amplification of trisomy 8-positive cells. Therefore, the inclusion of VPA into regimens for AML treatment has to be reconsidered.