bluuebunny/crossref_metadata_2025_split huggingface dataset:
T-bet Over-Expression in T Cells from Patients with Aplastic Anemia.
Authors: Solomou Elena E. , Keyvanfar Keyvan , Sloand Elaine M. , Weinstein Barbara , Nunez Olga , Young Neal S. 
Published: April 2020

Abstract
Acquired aplastic anemia (AA) is a bone marrow failure syndrome characterized by immune-mediated destruction of hematopoietic stem cells. T cells from patients with AA overproduce IFN-γ, a cytokine that inhibits hematopoietic stem cell proliferation and induces Fas-mediated apoptosis; stem cell depletion results in marrow hypoplasia and peripheral blood pancytopenia. In T cells, regulation of IFN-γ production occurs primarily at the level of transcription. A proximal site of the IFN-γ gene (−75 to −45bp of the IFN-γ promoter) is a binding site for different transcription factors including NFAT, AP-1, ATF, CREB, and T-bet. T-bet is a member of the T-box family of transcription factors, this family contains a highly conserved DNA binding domain, the T-box, that binds to a specific sequence in the promoter of different genes, including the IFN-γ promoter. T-bet is found in Th1 but not in Th2 cells and is the key regulator of Th1 development and function (Rengarajan et al., Immunol Today2000; 21: 479). The inducible expression of T-bet is mediated in part by Itk kinase (Sjabo et al., Science2005; 307: 430). In the present study, we examined T-bet protein levels in T cells from patients with AA. Samples from 17 of 20 patients examined (85%) by immunoblot showed increased T-bet protein levels in unstimulated T cells compared to normal controls (p = 0.0001). Normal controls showed undetectable T-bet protein levels in unstimulated T cells but T-bet expression was induced after 24 hrs of stimulation with PMA and ionomycin. In electrophoretical mobility shift assays, we observed increased T-bet binding to the proximal site of the IFN-γ promoter in T cells from patients with AA; no binding was detected in unstimulated T cells from healthy controls, but binding was present after stimulation for at least 24 hrs. T-bet protein levels correlated with disease activity. Patients with increased T-bet protein levels showed increased intracellular IFN-g levels compared to controls, as detected by flow cytometry (p&lt;0.05). Patients that expressed increased T-bet protein levels also showed increased levels of the Itk kinase (p=0.02). We examined if other kinases that lie downstream of Itk in the signal transduction activation cascade in T cells affected the inducible expression of T-bet. In normal T cells, rottlerin, a PKC-theta (PKC-𝛉) inhibitor, decreased T-bet protein levels by 50%; in AA T cells, rottlerin also decreased T-bet protein levels and IFN-γ intracellular levels by 50%. Our results suggest that the increased IFN-γ levels observed in AA are the result of activation of transcription of the IFN-γ gene by the regulator T-bet. Blocking of transcription of the IFN-γ gene by kinase inhibitors might represent a therapuetic strategy for AA and other human T cell-mediated autoimmune diseases.
Otx1 Enhances Erythroid Differenciation through Activation of the SCL Gene.
Authors: Sincennes Marie-Claude , Sanguin-Gendreau Virginie , Martin Richard , Grondin Benoit , Tremblay Mathieu , Cerisoli Francesco , Magli Christina , Hoang Trang 
Published: April 2020

Abstract
Members of the paired class of homeobox proteins are critical determinants of left-right asymmetry and establish the antero-posterior axis, suggesting that they could also be involved in asymmetric determination within the hematopoietic system. We have previously shown that mice lacking Otx1, a bicoid homeodomain-containing gene, exhibit an impairment of the erythroid compartment, associated with decreased SCL levels. In the present study, we show that Otx1 is coexpressed with SCL in yolk sac during embryonic development; in differentiating embryonic stem cells, Otx1 is upregulated with SCL in both primitive and definitive erythroid colonies, while Otx expression is absent in cardiomyocytes and skeletomyocytes. To address the role of Otx1 in hematopoiesis, we overexpressed Otx1 in primary hematopoietic cells using the MSCV retrovirus. The gain of Otx1 function gives rise to a 6-fold increase in endogenous SCL levels together with an increase in TER119-positive erythroid cells. Strikingly, the generation of CD11b-positive myeloid cells was almost abrogated by ectopic Otx1 expression, suggesting that Otx1 favours the erythroid lineage at the expense of the myeloid lineage. Furthermore, we took several approaches to provide molecular and functional evidence that SCL is a direct transcriptional target of Otx1. Indeed, Otx1 synergizes with GATA-1 to activate transcription from the SCL proximal promoter and this activity is dependent on the proximal GATA site of the SCL promoter. Next, we show by chromatin immunoprecipitation that Otx1 and GATA-1 occupy the SCL proximal promoter in vivo in erythroid cells. At the molecular level, we show that Otx1 physically interacts with GATA-1 in erythroid cells, and the homeodomain of Otx1 is sufficient for this interaction. Finally, a gain of function of SCL rescues the erythroid deficiency of Otx1−/− mice, consistent with the model in which SCL operates downstream of Otx1. Taken together, our observations indicate that Otx1, GATA-1 and SCL are involved in the same genetic pathway to specify the erythroid fate during hematopoiesis.
Characterization of a Megakaryocyte-Specific Enhancer of the Key Hemopoietic Transcription Factor GATA1.
Authors: Guyot Boris , Murai Kasumi , Fujiwara Yuko , Valverde-Garduno Veronica , Hammett Michele , Wells Sara , Dear Neil , Orkin Stuart H. , Porcher Catherine , Vyas Paresh 
Published: April 2020

Abstract
Specification and differentiation of the megakaryocyte and erythroid lineages from a common bipotential progenitor provides a well-studied model to dissect binary cell fate decisions. To understand how the distinct megakaryocyte- and erythroid-specific gene programs arise, we have examined the transcriptional regulation of the transcription factor GATA1, that is required for normal maturation of these two lineages. Megakaryocyte- and erythroid-specific mouse (m)GATA1 expression requires the mGata1 enhancer mHS-3.5. Within mHS-3.5, we previously showed that the 3′ 179 base pairs (bp) of mHS-3.5 are required for megakaryocyte but not red cell expression. Here, we show that mHS-3.5 binds key hemopoietic transcription factors in vivo (GATA1, SCL/TAL-1) and is required to maintain histone acetylation in the mGata1 locus in primary megakaryocytes. When deletional constructs containing mHS-3.5 were used to direct GATA1-LacZ reporter gene expression in transgenic mice, a 25 bp element within the 3′ 179bp in mHS-3.5, was critical for megakaryocyte expression. In vitro three uncharacterized DNA-binding activities A, B and C bind to the core of the 25 bp element, and these binding sites are conserved through evolution. Of these, only activity B is present in primary megakaryocytes but not red cells. Furthermore, mutation analysis in transgenic mice reveals that activity B is required for megakaryocyte-specific enhancer function. Bioinformatic analysis shows that sequence corresponding to the binding site for activity B is a previously unrecognised motif present in the cis-elements of other megakaryocyte-specific genes. In summary, we have identified a motif and a DNA-binding activity that are likely to be important in directing a megakaryocyte gene expression program distinct from that in red cells.
Severe Mucositis Adversely Affects Survival after Autologous Stem Cell Transplantation (ABMT) for Lymphoid Malignancies.
Authors: Bolwell Brian , Kalaycio Matt , Sobecks Ronald , Andresen Steven , Rybicki Lisa , Kuczkowski Elizabeth , Mendiola Sherry , Kohuth Joe , Bell Kimberly , Curtis Julie , Brown Stacey , Pohlman Brad 
Published: April 2020

Abstract
Mucositis is a well known short term complication of ABMT. Many studies of mucositis in ABMT, however, are flawed due to heterogeneity of both mobilizing regimens and high-dose preparative regimens. There is also sparse data on the long term consequences of mucositis after ABMT. This study retrospectively reviews all patients with lymphoid malignancies undergoing ABMT from 5/2000 to 2/2005 at our institution that received a uniform mobilizing regimen of VP-16 plus G-CSF and a uniform high dose preparative regimen of busulfan, cyclophosphamide and VP-16. 191 patients fit the entry criteria into this study. Mucositis was graded using the OMAS mucositis grading scale, which has a scoring range of 0–2.0. Severe mucositis for the purposes of this study was designated as having a maximal OMAS scale of ≥ 1.0. 87 patients experienced severe mucositis and 104 did not. Median age for patients was 52 years; underlying diagnoses were non-Hodgkin’s Lymphoma (n=155) and Hodgkin’s Disease (n=36). The two groups (developing severe mucositis vs not) were balanced with respect to disease status at transplant, number of courses of prior chemotherapy, prior exposure to radiation therapy of any kind, and elevated LDH at the time of transplant. Median CD34+ cell dose collected for the entire group was 8.5 x 106 /kg; there was no difference between the 2 groups. Severe mucositis correlated with mortality within 100 days of transplant. Patients with a maximal OMAS scale of &lt; 1.0 had 99% 100-day survival (103/104) as compared to 92% (80/87) for those with an OMAS scale ≥ 1.0 (p=0.015). To date, 30% of patients have relapsed with no difference in the two groups. However, Kaplan-Meier estimates of survival reveal that severe mucositis has a profound negative impact on survival (p=0.002) as shown graphically below:
Figure Figure
One of the key drivers of this difference in survival was the fact the patients with severe mucositis were more likely to experience pulmonary or multi-organ failure as a cause of death: 8 patients with severe mucositis died of these toxicities, as compared to zero in the less severe mucositis group. Multivariable Cox analysis was performed to analyze risk factors for mortality. Three variables were found to be significant: elevated LDH at transplant (p=0.03), number of prior chemotherapy regimens (for one regimen increase, p=0.024) and severe mucositis (p=0.003). In conclusion, patients that develop severe mucositis have a higher risk of mortality after ABMT. The etiology is likely multi-factorial; mucositis may directly contribute to mortality risk, and may also be a surrogate marker of other organ toxicities.
Melphalan 200mg/m2 (MEL 200) and MEL 140/DT-PACE Are Equally Effective in Multiple Myeloma (MM), While the Latter Is Less Toxic.
Authors: Tricot Guido , Reiner Maureen , Zangari Maurizio , van Rhee Frits , Barlogie Bart 
Published: April 2020

Abstract
MEL 200 is now generally accepted to represent the best preparative regimen for autotransplantation in MM patients. We have previously reported that DT-PACE is very effective in inducing rapid responses even in high risk myeloma (JCO 2003, 31: 73–80). The present study aimed at comparing outcome and toxicity of previously treated (≥ 2 cycles of prior therapy) MM patients, who were randomized to tandem transplants with either MEL 200 or MEL 140 plus full dose DT-PACE administered over two days (MEL/DT-PACE). The treatment in both arms consisted of one induction cycle with DT-PACE, followed by tandem transplants (randomized), one consolidation cycle with DT-PACE and 2 years of maintenance therapy with dexamethasone (20mg/d, days 1–4, every 3 weeks) plus thalidomide 100mg/day. 97 patients were enrolled; 93 collected sufficient stem cells for transplantation and were randomized to MEL 200 (N=48) or MEL140/DT-PACE (N=45). Event-free (EFS) and overall survival (OS) were analyzed using Kaplan-Meier plots. Graphs were compared with logrank statistics. Median age was 57 years. Prior to study enrollment β2M was ≥ 4mg/L in 28%; CRP ≥ 4 mg/L in 59%; LDH ≥ 250 U/L in 16%. 16% had &gt; 12 months preceding therapy and 27% showed abnormal metaphase cytogenetics. Baseline characteristics were similar in both groups, except for a trend of more patients with β2M ≥ 4mg/: in the MEL 200 arm (p=0.09). 100% of randomized patients proceeded to the first transplant and 82% to a second; 87% in the MEL/DT-PACE and 77% in the MEL 200 arm (p=0.23). The CR rates were identical (44% and 42%, respectively). EF/OS at 3 years were 51%/71% in the MEL/DT-PACE arm and 55%/79% in the MEL 200 arm (p=.89/.73) (Figure 1). Recovery of ANC &gt; 500μl plus platelets &gt; 20,000/μl untransfused, was comparable after the first (p=0.21) and second transplant (p=0.17). Grade 3–5 toxicity was lower in the MEL/DT-PACE arm in terms of mucositis (p=.006) and febrile neutropenia (p=.001). We conclude that both preparative regimens, MEL 200 and 140 with the addition of DT-PACE, appear equally effective in previously treated MM patients. However, the Mel 140 resulted in a significantly lower incidence of mucositis and febrile neutropenia and may thus be preferred in patients not in excellent clinical condition prio to transplantation.
Figure Figure
A Critical Role of Blockade of Cell Differentiation in BCR-ABL-Induced B-Cell Acute Lymphoblastic Leukemia (B-ALL): Basis for Superb Therapeutic Effect on B-ALL in Mice by Promotion of Pro-B Leukemic Cell Differentiation and Treatment with Imatinib.
Authors: Hu Yiguo , Kong Linghong , Staples Kevin , Mills Kevin , Monroe John G. , Li Shaoguang 
Published: April 2020

Abstract
The BCR-ABL oncogene induces human Philadelphia-positive (Ph+) B-cell acute lymphoblastic leukemia (B-ALL) and chronic myeloid leukemia (CML) that advances to acute phase of CML called blast crisis. In this acute phase, CML patients can develop either B-ALL or acute myeloid leukemia. In B-ALL, differentiation of leukemic cells are blocked at pro-/pre-B stage, and the underlying mechanism is unknown. We hypothesize that this blockade of B-cell differentiation may be important for the development of B-ALL induced by BCR-ABL, and if so, promotion of B-leukemic cell differentiation would create a novel therapeutic strategy for B-ALL. To test this hypothesis, we first compared the percentages of IgM+ B-leukemic cells in BALB/c and C57BL/6 (B6) mice with BCR-ABL-induced B-ALL, because we have previously found that B-ALL develops more quickly in BALB/c mice than in B6 mice (Li et al, J. Exp. Med.189:1399–1412, 1999). We expressed BCR-ABL in bone marrow (BM) using retroviral transduction and transplantation in these two different strains of inbred mice to induce B-ALL. There were significantly more peripheral blood B220+ B cells in BALB/c B-ALL mice than those in B6 mice, correlating to faster B-ALL in BALB/c mice than in B6 mice. Among these B220+ cells, IgM+ cells were much less in BALB/c mice than in B6 mice. We also compared rearrangement of the B cell antigen receptor (BCR) heavy chains (m chains) between BALB/c and B6 backgrounds using BCR-ABL-expressing pro-B cell lines isolated from the B-ALL mice. Normal m chains rearrangement was found in B6 leukemic cells, but not in BALB/c leukemic cells. These results indicate that more differentiated B-leukemic cells are associated with less aggressive disease. To further demonstrate the role of blockade of B-cell differentiation in B-ALL development, we induced B-leukemic cell differentiation by co-expression of BCR-ABL and intact immunoregulatory tyrosine activation motifs (ITAM) contained in immunoglobulin (Ig)_/Igß complexes in BM cells of B-ALL mice, comparing to expression of BCR-ABL alone. We treated these mice with imatinib (orally, 100 mg/kg, twice a day). The treated mice with B-ALL induced by co-expression of BCR-ABL and ITAM lived three-week longer than those with B-ALL induced by BCR-ABL only, with some mice in long-term remission. Prolonged survival was associated with 50% increased B220+/IgM+ B-leukemic cells in peripheral blood of the mice. Taken together, our results demonstrate that blockade of B-cell differentiation is critical for the development of B-ALL induced by BCR-ABL, and provide a rationale for combination therapy of B-ALL with imatinib and induction of leukemic cell differentiation.
WP1066: A Novel PI-3K Inhibitor with Antileukemic Activity in Philadelphia Chromosome-Positive ALL.
Authors: Ferrajoli Alessandra , Faderl Stefan , Wang Tony , Priebe Waldemar , Kantarjian Hagop , Talpaz Moshe , Estrov Zeev 
Published: April 2020

Abstract
Prognosis for patients with Philadelphia chromosome (Ph) positive ALL remains dismal. Ph+ ALL is characterized by the activation of several tyrosine kinases that provide the neoplastic clone with its proliferative capacity and survival advantage. We found that WP1066, a novel derivative of the tyrphostin AG490, inhibits the JAK-STAT pathway and cytokine-dependent and independent signaling pathways. Therefore, we sought to investigate the activity of WP1066 in Ph+ ALL. To do this, we first studied the effect of WP1066 on the Ph+ ALL cell lines Z-119 and Z-181 (Estrov Z et al. J. Cell Physiol.166(3):18, 1996). Using the MTT assay we found that WP1066 inhibited the growth of both Z-119 and Z-181 cells in a concentration-dependent manner with only 8% and 4% of the cells surviving at a concentration of 4 mM, respectively. Similarly, the clonogenic growth of both Z-119 and Z-181 cells was effectively inhibited by WP1066 with more than 90% reduction in colony numbers at concentration of 4 mM. Using Western Immunoblott analysis of cell lysates, we found that 4 mM of WP1066 induced caspase-3 cleavage in a time- and dose-dependent manner in both Z-119 and Z-181 cells. In addition, WP-1066 downregulated uncleaved poly (adenosine diphosphate-ribose) polymerase (PARP) and upregulated cleaved PARP protein levels in a time-dependent manner after 2 hours of exposure to 4 mM. We further evaluated induction of apoptosis using the annexin V-FITC assay and showed a dose dependent increase of the fraction of apoptotic cells in both Z-119 and Z-181 cells. After 24 hour of exposure to 4 mM of WP1066 the fraction of apoptotic cells increased by 23% and 43%, respectively. To elucidate the mechanisms by which WP1066 induces growth inhibition and apoptosis in Ph+ ALL cells, we investigated the effect of this agent on the phosphatidylinositol 3-kinase (PI-3K) pathway because the PI-3K pathway is constitutively activated in Ph+ leukemias. We found that WP1066 inhibited the phosphorylation of AKT in a time-dependent fashion in both cell lines and that this inhibitory effect lasted for 24 hours.
In conclusion, our data suggest that exposure to WP1066 induces caspase-dependent apoptosis, is associated with PI3-K inhibition and reduces the growth of the Ph+ cell lines Z-119 and Z-181. The activity of WP1066 in Ph+ ALL should be further studied.
Coculture of Pediatric Acute Lymphoblastic Leukemia (ALL) Blasts with CD40 Ligand Transfected Cells Leads to Changes of Surface Antigens and RNA Expression.
Authors: Stachel Daniel K. , Eickelmann Uta , Meilbeck Rita , Albert Michael H. , Buhmann Raymund , Hallek Michael , Schmid Irene 
Published: April 2020

Abstract
Although multi-agent chemotherapy is remarkably successful in the treatment of pediatric acute lymphoblastic leukemia (ALL), about 25% of patients experience relapse. A possible way to increase the cure rate for leukemia could be to modulate the immune response against leukemic cells.
It is known that ALL blasts are poor stimulators of cellular immune responses. This is believed to be mainly the result of a reduced presentation of costimulatory molecules on the surface of the ALL blasts.
For B cells, CD40 is an essential molecule which can be targeted therapeutically through its ligand, CD40 ligand or CD152. Normal B cells can induce cytotoxic T cell responses following stimulation with a soluble trimeric CD40 ligand.
We therefore hypothesized that by coculture with CD40 ligand transfected HeLa cells for four days, pediatric ALL blasts could be induced to upregulate costimulatory molecules, apoptosis inducing ligands and cytokines. The expression of the surface antigens CD40, CD40 ligand, CD80, CD86, CD95/fas, HLA-ABC and HLA-DR was evaluated by flow cytometry and the RNA expression of CD40, CD80, CD86, Fas ligand (FasL), TRAIL, IL-4, IL-6, IL-10, TGF-β was assessed by semiquantitative RT-PCR.
We found that coculture with CD40 ligand transfected HeLa cells significantly increased the expression of CD40 ligand, CD80, CD86 and CD95/fas while the expression of HLA-ABC, HLA-DR and CD40 remained unchanged. We found a significantly increased RNA expression of IL-6, TGF-β and CD80, a small but not significant increase of CD86, but no change in expression for IL-4, IL-10, FasL, TRAIL and CD40 after coculture. Addition of IL-4 to the culture did not influence the results.
In summary CD40 ligand mediated stimulation lead to increased expression of costimulatory molecules CD80 and CD86 and the pro-apoptotic CD95/fas, while the anti-apoptotic cytokines IL-6 and TGF-β were also upregulated.
Our results show that stimulation through CD40 ligation upregulates costimulatory molecules on pediatric ALL blasts, while it has differential effects on apoptosis inducers. This might have functional consequences which could be therapeutically exploited to modulate the immune system in an attempt to increase cure rates in pediatric ALL.
Vitamin K3 Selectively Induces Apoptosis in Acute Lymphoblastic Leukemia Cells with Constitutive Activation of IKKα/NF-kB Activation.
Authors: Zhu Ningxi , Gu Lubing , Findley Harry W. , Chiang Kuang-Yueh , Zhou Muxiang 
Published: April 2020

Abstract
Although the cytotoxic effect of vitamin K3 (VK3) on human cancer cells has been repeatedly reported, no clear conclusions from either in vitro or in vivo tests have so far been made for VK3 as an anticancer agent due to marked inter-tumor variability of efficacy in response to VK3 treatment. Here, we report that sensitivity of neoplastic cells to VK3-induced killing depends on IKKα expression/NF-kB activation in the cells. We tested the sensitivity to VK3 of 14 leukemic cell lines established from children with acute lymphoblastic leukemia (ALL). The 14 lines were classified into three groups: IKKα +/NF-kB+, IKKα +/NF-kB−, IKKα−/NF-kB−. IKKα +/NFkB+ cell lines that are generally resistant to doxorubicin are more sensitive to VK3 induced cell death than are the IKKα +/NFkB− lines that are usually sensitive to doxorubicin. The median of IC 50 values of VK3 and doxorubicin as tested by WST analysis for IKKα +/NFkB+ cells were 3.92 mM and 1.58 mM, respectively, compared to IKKα +/NFkB− cells (7.3 mM of VK3 and 0.71 mM of doxorubicin, p&lt;0.01, t-test). Assays by testing activation of caspase and cleavage of death substrate PARP as well as flow cytometry showed that apoptosis was induced in a line with high levels of IKKα/NF-kB activation at 2 h after VK3 treatment. In contrast, apoptosis was not induced by VK3 even at 48 h post-treatment in two lines that lack IKKa expression and NF-kB activation. To test if IKKα/NF-kB is a molecular target of VK3 inducing apoptosis in ALL, we examined the expression and activation of IKKα/NF-kB in VK3-treated cells. VK3 specifically reduced IKKα expression and inhibited NF-kB activation, resulting in downregulation of NF-kB-mediated gene expression and apoptosis. These results suggest that inhibition of IKKα/NF-kB signaling pathway is essential for VK3 to induce cell death, and that VK3, a dietary factor with no cytotoxic effect on normal cells, would be a useful adjuvant in the treatment of ALL and other cancer patients whose neoplastic cells express constitutive NF-kB and are resistant to chemotherapy.