bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors Affecting Thrombopoietin Production from Bone Marrow Stromal Cells.
Authors: McIntosh Bryan J. , Fox Norma E. , Kaushansky Kenneth 
Published: October 2019

Abstract
Thrombopoietin (TPO) is the primary regulator of megakaryopoiesis and therefore also the most important determinant of the number of platelets in circulation. The regulation of TPO blood concentration is complex, with at least a significant component mediated by removal and degradation of the hormone by the mature circulating platelet mass. In this way, if the production of TPO were fixed, when the number of platelets rises, an increased amount of TPO is removed from the plasma, resulting in an inverse relationship between platelet counts and TPO concentration. However, several studies hint at the existence of additional mechanisms in which TPO production is altered in response to physiological and pathologic conditions. We, and others, have previously reported that TPO mRNA is increased in the bone marrow of mice or humans after either immune- or radiation-mediated thrombocytopenia, although hepatic levels remain unchanged by this manipulation. To further explore the mechanism(s) of this effect, we utilized in vitro marrow stromal cell models to study the effects of blood proteins on TPO production. As an initial hypothesis we determined if platelet-derived proteins in serum might suppress TPO production from both a marrow stromal cell line, OP9, or primary murine marrow stromal cells derived from long-term hematopoietic cultures. As assessed by quantitative RT-PCR we found that TPO mRNA levels increase a mean of 2.8-fold±0.7 (n = 3) twelve hours following the removal of serum from the culture. Similar results were obtained from primary murine marrow stromal cells; TPO mRNA levels rose a mean of 2.9-fold±0.9 (n = 4) within sixteen hours of serum deprivation. In contrast, TPO transcript levels were unaffected by the same manipulation of serum in the hepatocyte cell line HEPA1c1c7. As the removal of serum might have induced a stress response in the cells, we tested whether other cell stressors might mimic this response; we found that neither UV irradiation nor treatment with toxic metals such as nickel, cobalt, or cadmium produced any rise in TPO mRNA in marrow stromal cells. Furthermore, to test whether a cell cycle arrest triggered by serum deprivation might mediate these effects, we treated stromal cells with cell cycle inhibitors, but failed to find any affect on TPO transcript levels in stromal cells. Further biochemical fractionation of serum suggested that one or more distinct proteins is responsible for this effect, demonstrated by the ability of both ammonium sulfate precipitation and ion exchange chromatography to partition the suppressive effects of serum. However, the active agent in serum is not TPO itself, as the addition of 150 ng/ml of the pure hormone did not suppress stromal cell TPO transcript levels. Knowledge of this novel regulatory mechanism should be useful in treating platelet disorders and perhaps also during stem cell transplantation, a setting in which TPO is known to play a vital role.
Evidence for Killing of Mesenchymal Stem Cells (MSC) by Autologous Natural Killer Lymphocytes.
Authors: Poggi Alessandro , Massaro Anna-Maria , Negrini Simone , Pierri Ivana , Balocco Manuela , Michelis Gianluca , Aquino Sara , Albarello Alessandra , Gobbi Marco , Zocchi Maria Raffaella 
Published: October 2019

Abstract
In this study, Mesenchymal Stem Cells (MSC) were obtained from bone marrow of 10 patients suffering from acute myeloid leukemia (AML), six M0/1 two M2, and two M5 (according to the FAB classification), 8 out of 10 in post-chemotherapy complete remission. These cells differentiated into adipocytes or osteoblasts under appropriate culture conditions. MSC were CD44+, CD73a+ CD73b+ CD105+, beta1 integrin+, ICAM1+, HLA-I+, HLA-II+ (variable proportions), CD45−, CD31−, CD34− and they constitutively expressed the stress-inducible MHC-related molecules MIC-A and the UL16 (induced at the surface of cells infected by cytomegalovirus) binding protein ULBP3. These molecules are reported ligands for the NKG2D receptor expressed by natural killer (NK) and CD8+ T lymphocytes, effector cells that are thought to play a role in host defence against tumors. NK cells have also been shown to regulate normal differentiation of hemopoietic precursor into the myeloid or lymphoid cell lineage. Moreover, it has been stated that NK cells are not able to damage autologous cells, as they receive negative signals through inhibitory receptors, including killer Ig-like receptors (KIR) or C-type lectin inhibitory receptors (CLIR), which bind to HLA-I discrete alleles. Surprisingly, we found that autologous IL2-activated, but not freshly isolated, NK cells lysed MSC, while T lymphocytes did not kill self or non-self MSC. Binding of ICAM-1 expressed by MSC to its receptor, the integrin LFA-1, expressed by NK cells plays a key role in MSC/NK interaction. More importantly, NKG2D/MICA and/or NKG2D/ULBP3 engagement is responsible for the delivery of lethal hit. Conversely, it appears that HLA-I molecules do not protect MSC from NK cell-mediated injury. Taken together, these data suggest that NK cells, when activated as it may occur during the first response to viral infections, are able to eliminate MSC, thus altering the normal interactions with hemopoietic precursors and possibly affecting their differentiation. This mechanism might also contribute to the development of aberrant precursors as observed in acute leukaemias.
Empirical Antifungal Therapy (Rx) with Caspofungin (CAS) vs Liposomal Amphotericin B (L-AmB) for Persistently Febrile Neutropenic Patients (Pts) with Acute Myeloid Leukemia (AML).
Authors: Maertens Johan A. , Teppler Hedy , Lupinacci Robert , Bourque Michael , DiNubile Mark , Sable Carole 
Published: October 2019

Abstract
Background: In a double-blind randomized trial of empirical antifungal Rx for persistently febrile neutropenic pts, CAS was as effective as and better tolerated than L-AmB. We now examine the results of this study in the subgroup of pts with AML.
Methods: Randomization to CAS (70 mg x 1, then 50 mg/d) or L-AmB (3 mg/kg/d) was stratified by risk category [high risk = allogeneic hematopoietic stem cell transplant or relapsed acute leukemia] and use of antifungal prophylaxis. The primary efficacy endpoint was % of treated pts with documented fever and neutropenia who had a successful outcome defined by all the following: successful Rx of baseline (BL) invasive fungal infection (IFI) (if any), no breakthrough (BT) IFI to 7 d post-Rx, survival @7d post-Rx, no premature discontinuation (DC) due to lack of efficacy or study drug toxicity, and fever resolution x 48 hr during neutropenia.
Results: 703/1095 (64%) of the treated pts had AML, including 364/556 (65%) and 339/539 (63%) in the CAS and L-AmB groups, respectively. Demographic characteristics were similar in AML pts in both Rx groups. 27% of CAS and 22% of L-AmB pts with AML were high risk. Median days of Rx were: CAS, 12; L-AmB, 11. The table shows % AML pts with a successful outcome by Rx group.
% AML pts with a successful outcome by Rx group
CAS (N=364) L-AmB (N=339) Difference (CAS - L-AmB) 95% CI for difference between treatment groups † 7/14 CAS and 5/16 L-AmB pts had successful Rx of BL IFI. Success Rx of BL IFI † 50 31 19 (−16, 53) No BT IFI 93 95 −2 (−5, 2) Suvival @ 7d post-Rx 92 88 4 (0, 8) No premature DC 87 86 2 (−3, 7) Fever resolution 48 46 2 (−5, 9) All of the above 40 38 2 (−5, 10)
The composite success rates for the high risk AML pts were 46/99 (46%) for CAS and 31/76 (41%) for L-AmB.
Conclusions: In this post hoc subgroup analysis, CAS provided an effective and generally well-tolerated option for the empirical Rx of persistently febrile neutropenic pts with AML.
Oligoclonal/Multiclonal Pattern of Kaposi Sarcoma-Associated Herpesvirus (KSHV/HHV-8) Episomes in Primary Effusion Lymphoma Cells.
Authors: Boulander Emmanuelle , Duprez Renan , Delabesse Eric , Gabarre Jean , Macintyre Elizabeth , Gessain Antoine 
Published: October 2019

Abstract
Primary effusion lymphoma (PEL) is a rare non-Hodgkin lymphoma of B-cell lineage origin, developed in the serous body cavities and mostly observed in the course of HIV infection. PEL tumor cells are latently infected with Kaposi sarcoma-associated herpesvirus (KSHV) and in most cases, co-infected with Epstein-Barr virus (EBV). As a virological marker of clonality in PEL, we analyzed the fused terminal repeat regions (TR) of KSHV episomes using pulsed-field gel electrophoresis and Southern blot hybridization, in 15 primary PEL tumors including 10 EBV+ cases, and in 6 PEL cell lines. The cellular clonality was assessed on the same genomic DNA samples, by Southern blot and PCR detection of monoclonal immunoglobulin heavy chain (IgH) VDJ gene rearrangements, associated in the co-infected PEL with Southern blot analysis of the fused termini of EBV episomes. Monoclonal IgH gene rearrangements were detected in 87% (13/15) of primary PEL tumors using Southern blot, in 73% (11/15) using PCR analysis, and in all tumors considering both methods. All the co-infected PEL also displayed a monoclonal EBV infection. However, only 5 primary PEL tumors were found to be monoclonally infected with KSHV. In the 10 remaining cases, as well as in the KSHV+/EBV-negative BC-3 cell line, we found a biclonal (2 bands)(n=3) or an oligoclonal/multiclonal pattern (3–6 bands)(n=7) of KSHV episomes. KSHV infection of non-tumoral contaminating cells, superinfection mechanisms from lytically infected tumor cells, or viral integration events might explain such discordant findings between the viral and cellular clonality of PEL.
Thrombopoietin as an Independent Prognostic Marker in Chronic Lymphocytic Leukemia.
Authors: Koller Charles Asa , Bekele B. Nebiyou , Zhou Xian , Park Charles , Estrove Zeef , O’Brien Susan , Keating Michael , Jilani Iman , Giles Francis J. , Kantarjian Hagop M. , Albitar Maher 
Published: October 2019

Abstract
Several cytokines and growth factors are involved in the regulation of megakaryocytopoieses and platelet formation. Interleukin-11 (IL-11), IL-6, IL-3, IL-1b, and thrombopoietin (TPO) act synergistically to promote proliferation and maturation of megakaryocytes. Recombinant IL-11 and TPO are under clinical investigation as supplements to stimulate thrombopoiesis in patients with cancer. We investigated the plasma levels of TPO in 127 patients with chronic lymphocytic leukemia (CLL) and correlated these levels with platelet counts and various laboratory and clinical characteristics. TPO levels were significantly higher in patients with CLL (median, 232 pg/mL; range, 26.4–2714.5 pg/mL) than in healthy control subjects (P <0.01). More importantly, higher levels of TPO were associated with advanced Rai stage (P <0.0001), higher b-2-microglublin (b2-M) levels (P<0.001), and the presence of mutation in the IgVH gene (P <0.001). TPO levels were inversely correlated with platelet count (P = 0.002). Univariate Cox proportional hazard models demonstrated that high TPO levels in CLL patients were associated with shorter survival (P <0.0001); multivariate analysis demonstrated that this association was independent of the IgVH mutation status, b2-M levels, and Rai stage. Recursive partitioning showed that a cut-point of 639.4 pg/mL separated CLL patients into two major groups with a significant difference in survival (P <0.0001). When b2-M level was added to this model, its effect was masked by the effects of TPO in patients with TPO >639.4 pg/mL. However, among patients with TPO levels =639.4 pg/mL, those with b2-M levels >4.95 mg/L had significantly shorter survival than those with lower b2-M levels. These data not only emphasize the importance of TPO in reflecting the aggressiveness of CLL, but also suggest that TPO and b2-M can be used to predict clinical behavior in this disease and may replace the need for determining IgVH mutation status. Further studies are needed to determine if the prognostic role of TPO is due to its direct effects on the growth of the leukemic clone or simply reflects a general failure in the homeostatic regulation of various cytokines.
Figure Figure
Regulation of Tissue Factor Signaling by Tissue Factor Pathway Inhibitor.
Authors: Ahamed Jasimuddin , Belting Mattias , Ruf Wolfram 
Published: October 2019

Abstract
Tissue factor initiates the coagulation cascade as well as cellular signaling through the activation of cell surface protease activated receptors (PARs), relevant to inflammation, tumor metastasis and angiogenesis. Tissue factor pathway inhibitor-1 (TFPI-1) is the major regulator of TF initiated coagulation, but recombinant TFPI-1 (rTFPI-1) has shown limited efficacy on sepsis-associated inflammatory responses and mortality. In TNF-stimulated human umbilical vein endothelial cells (HUVECs), we demonstrate with specific blocking antibodies that endogenous TFPI effectively controls TF procoagulant activity as well as TF-dependent signaling through PAR1 and PAR2. The effect of rTFPI-1 on coagulation and signaling was tested in TF-transfected CHO-cells or in HUVECs transduced with TF to overcome the inhibitory threshold of endogenous TFPI-1. Under conditions that specifically measure signaling of the ternary TF-VIIa-Xa complex, 2.5–5 nM rTFPI-1 inhibited TF-dependent Xa generation by >80% but the signaling of the ternary complex through PAR1 at these concentrations of rTFPI-1 was only marginally inhibited. Moreover, studies with proteoglycan-deficient CHO cells provided genetic evidence that PG binding facilitates the inhibitory activities of rTFPI-1 on coagulation and signaling. In HUVECs that co-expressed PAR2 with TF, three different signaling responses of the ternary TF-VIIa-Xa complex were inhibited by ~ 50% at 1.2–2.5 nM rTFPI-1, but the inhibitory potency of rTFPI-1 to block Xa generation was consistently higher relative to its effect on signaling. These data demonstrate that coagulation initiation phase signaling can occur in the absence of the activation of coagulation. The results also establish that endogenously expressed TFPI-1, known to be entirely GPI-anchored in endothelial cells, is a potent, negative regulator of ternary complex-mediated PAR signaling. The efficacy of rTPFI-1 appears to be influenced by the presence of PAR2, further emphasizing the close reciprocal signaling linkage of PAR2 and TF demonstrated in angiogenesis and cellular signaling targeting the TF cytoplasmic domain by phosphorylation.
Enhanced Primary CML Stem Cell Elimination by Bryostatin Priming with Imatinib Mesylate In Vitro.
Authors: Jorgensen Heather G. , Allan Elaine K. , Mountford Joanne C. , Richmond Linda , Elliott Moira A. , Holyoake Tessa L. 
Published: October 2019

Abstract
In chronic myeloid leukemia (CML), CD34+ quiescent stem cells are sensitive to the anti-proliferative but not the pro-apoptotic effects of imatinib mesylate (IM; Gleevec®, Glivec®). Bryostatin-1 (bryo), a Protein Kinase C modulator, was investigated to determine whether it would increase IM-mediated apoptosis either through initiation of cycling of G0/G1 Ph + cells or reversal of the IM-induced anti-proliferative response. The Ph+ K562 cell line and primary CD34+ CML cells were studied. Cell cycle status was assayed by propidium iodide uptake. Following exposure to IM, 86 ± 1 % (mean ± SEM) of surviving K562 cells was in G0/G1 as compared to 52 ± 2 % in the control (p < 0.001). After accounting for IM-induced cell kill, the absolute number of viable G0/G1 cells was significantly increased, confirming the anti-proliferative, anti-apoptotic effect. However, priming for 24 hours with bryo both increased K562 total cell kill and normalised the percentage of cells recovered in G0/G1 thus reducing their absolute number. To assess the effect of priming with bryo on primary cells, endpoints on two levels were investigated: firstly, at the total cell, and secondly, at the stem cell level. For total primary CML CD34+ cells, as compared to untreated control (= 100 %), 56 ± 2 % survived 96 hours treatment with 5 μM IM, whereas 37 ± 2 and 24 ± 2 % survived 1 and 10 nM bryo alone, respectively (n = 7). Priming with bryo prior to IM (5 μM) significantly enhanced bryo-induced total cell death (19 ± 2 and 12 ± 1 % surviving 1 and 10 nM bryo then IM, respectively; p < 0.03). Critically, within the G0/G1 CD34+ cells, 59 ± 3 % of input cells survived IM (5 μM) alone (n = 7). Bryo alone (1 or 10 nM) significantly reduced the proportion of cells recovered in G0/G1 (35 ± 3 and 23 ± 2 %) relative to both the untreated control and IM treatment alone (p < 0.02). Bryo in scheduled combination with IM, further significantly reduced the number of cells recovered in G0/G1 (16 ± 3 and 9 ± 1 %) with respect to IM alone (p < 0.001) and bryo alone (p < 0.05). Thus, it was the combination that was more potent than each individual agent. These results suggest that carefully scheduled drug combinations may prove more efficacious within the Ph+ stem cell compartment than IM monotherapy. Specifically, inclusion of an agent to antagonise the anti-proliferative effect of IM is warranted.
Incidence and Prognosis of RTKs and RAS Mutations in CBF AML. A Retrospective Study of French Adult ALFA and Pediatric LAME Trials.
Authors: Boissel Nicolas , Leroy Hugues , De Botton Stephane , Leblanc Thierry , Philippe Nathalie , Baruchel Andre , Hermine Olivier , Dombret Herve , Preudhomme Claude 
Published: October 2019

Abstract
Introduction: In core binding factor (CBF) acute myeloid leukemia (AML), the disruption of CBFa (AML1) or CBFb genes through t(8;21) or inv(16) impairs normal hematopoietic differentiation, but is considered to be insufficient to induce leukemogenesis. The need of an additionnal oncogenic event that promotes cellular proliferation has been suggested. This proliferative signal may be delivered by mutated receptor tyrosine kinases (RTKs) or RAS proto-oncogenes. In a retrospective study, we evaluate the incidence and the prognosis of RTKs (FLT3/D835, KIT/D816 and KIT/Ex8 insertion/deletion) and N/K-RAS mutations in patients with CBF AML.
Patients: Genomic DNA were obtained from the bone marrow or blood of 81 patients under 60 years with CBF AML (t(8;21)/inv(16) : 48/33) : 21 treated in the pediatric LAME trial (27/6) and 60 in the adult ALFA trial (33/15) between 1990 and 2004. The median follow-up is 5 years.
Results: RTKs mutations are found in 15/74 (20%) patients. KIT mutations are present in 11/74 (15%) patients, at a lower rate than previously described. KIT/D816 mutations are observed in 2/49 (4%) t(8;21) patients and 1/32 (3%) inv(16) patients. KIT/Ex8 mutations are slightly more present in inv(16) than in t(8;21) patients (5/32 vs 3/42, 16% vs 7%). One of the 5/81 patients (6%) with FLT3/D835 mutations also presents a KIT/Ex8 mutation. RAS mutations rates are significantly higher in inv(16) than in t(8;21) patients (11/33 vs 4/38, 33% vs 11%), with mostly N-RAS mutations (75%). No correlation between RTKs or RAS mutations and age or WBC is observed. Four patients did not achieve complete remission (CR rate : 95%), 2 with FLT3/D835 and 3 with RAS mutations. In univariate analysis, RTKs mutations are significantly associated with a shorter OS and EFS (p=.001 and p=.02, resp.) KIT mutations are associated with a shorter EFS and RFS (p=.002 and p=.003) in t(8;21) patients but do not affect the outcome of inv(16) patients in our study. Patients with FLT3/D835 mutations have significantly shorter OS, EFS and RFS (p<.0001, p<.0001 and p=.0007, resp.). The outcome of each subgroup of CBF AML is affected by FLT3/D835 status. RAS mutations have no impact on outcome. Multivariate analysis show a persistent significant prognostic impact of RTKs mutations on OS, RFS and EFS.
Conclusion: Inv(16) and t(8;21) cytogenetics are classically associated with a low risk of relapse. Patients with CBF AML are no more considered by many teams for allogeneic stem cell transplantation, even with a related donor. However, screening for RTKs mutations may identify patients with a more adverse outcome and thus susceptible to benefit from intensified protocols or tyrosine kinase inhibitors.
Novel Stratification Scheme for AML Based on a Large-Scale DNA Microarray Analysis of CD133-Positive Blasts.
Authors: Mano Hiroyuki , Yamashita Yoshihiro 
Published: October 2019

Abstract
AML is a clonal disorder of immature hematopoietic blasts and has a variable clinical outcome. Current classification of AML is based predominantly on the cytogenetic abnormalities and morphology of the malignant blasts and is not always helpful for optimization of treatment strategy. It is, for instance, very difficult to predict the prognosis of AML patients with a normal karyotype, who constitute ~50% of the AML population. DNA microarray analysis has the potential to provide a novel stratification scheme for AML patients, which is based on gene expression profile, and might help to predict the prognosis of, and optimize the treatment strategy for, each affected individual. However, leukemic blasts derived from bone marrow (BM) of AML-related disorders, are not homogeneous. The blasts may constitute from 20% to almost 100% of mononuclear cells (MNCs) in the marrow. Furthermore, given that many leukemic blasts possess the ability to differentiate to a certain extent, the marrow of AML patients contains not only the immature blasts (leukemic stem clone) but also differentiated blasts. A simple comparison of BM MNCs among heterogeneous AML patients is thus likely to reveal a large number of changes in gene expression that only reflect differences either in the percentage of blasts or in the differentiation ability of the blasts. To minimize such population-shift effects in microarray analyses, we established a large-scale cell depository “Blast Bank” for the storage of CD133 (AC133)-positive hematopoietic stem cell-like fractions from individuals with a wide range of hematopoietic disorders. In the present study, we have used Affymetrix HGU133 A&B microarrays to measure the expression profiles of ~33,000 genes in the Blast Bank specimens of 99 adults with AML-related disorders: 83 individuals with AML and 16 patients in the RAEB stage of MDS. In contrast to the previous microarray analyses of BM MNCs of AML, unsupervised hierarchical clustering of the subjects based on the expression profile did not separate the patients into FAB subtype-matched subgroups. Comparison of gene expression profile between the long-time and short-time survivors has identified a small number of outcome-related genes. Supervised class prediction, based on these genes, with k-nearest neighbor method or Cox proportional hazard model both succeeded to clearly separate individuals into subgroups with statistically distinct prognoses. Our analysis may pave a way toward the expression profile-based novel stratification scheme for AML.