bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correlation between WT1 Levels and Chimeric Transcripts in Core Binding Factor AML: Discrepancies Are Not Uncommon AML1-ETO Leukemias.
Authors: Lasa Adriana , Carricondo Maite , Cilloni Daniela , Brunet Salut , Aventin Anna M. , Sierra Jorge , Nomdedeu Josep F. 
Published: October 2019

Abstract
The Wilms tumor gene (WT1) was identified as a tumor suppressor gene coding for a zinc-finger transcription factor. It has been demonstrated that WT1 is overexpressed in acute leukemias and detection of increased levels of WT1 transcripts mainly in peripheral blood, has been associated with clonal growth and relapses. Most AML patients do not have a suitable molecular marker for minimal residual disease (MRD) monitoring. WT1 quantification seems to be an attractive strategy of universal leukemia follow-up. Bone marrow samples from 46 core binding factor (CBF) AML patients were tested for WT1 expression in parallel to AMLI/ETO and CBFb/MYH11quantification. Total RNA was purified using the Trizol reagent (Invitrogen). Chimeric detection was performed following the BIOMED recommendations. The WT-1 mRNA expression was measured by real-time quantitative polymerase chain reaction (RQ-PCR) in an ABI7700 genetic analyzer (Applied Biosystems, Foster City). For WT1 copy number titration the IPSOGEN plasmid was employed (Ipsogen, Marseilles). One hundred and fifty bone marrow (BM) samples from AML1-ETO patients (23 samples at diagnosis and 127 during follow-up) and 195 from CBFbeta-MYH11 cases (21 samples at diagnosis and 174 during follow-up) were included in the study. Bone marrow samples from 6 healthy donors were used to establish the highest acceptable value of WT1 copy number (80 copies). The WT1 expression was significantly increased (up to 3 orders) in bone marrow samples of AML patients at diagnosis compared to BM samples of healthy donors (P < 0.0001). Relapses were observed exclusively in the CBFbeta-MYH11 group and were always preceded by rising amounts of WT1 levels. A good concordance between WT1 levels (80 copies) and prognostically relevant chimeric trancript copy number (1 copy) was detected in 96.23% of the samples. Discrepancies between WT1 and specific fusion genes were observed in 11 AML1-ETO samples and in two CBFbeta-MYH11 cases. In ten follow up AML1-ETO samples with copy values of 1 or less a WT1 result exceeding the 80 threshold was detected. This discordant result was found in a single CBFbeta-MYH11 sample. Our findings suggest that WT1 is a reliable MRD marker in CBFbeta-MYH11 AML. It remains to be investigated the meaning of high titers of WT1 in AML1-ETO acute leukemias.
SNS-595 a Novel S Phase Active Cytotoxic Acts Synergistically with Cytarabine To Reduce Bone Marrow Cellularity and Circulating Neutrophils.
Authors: Arbitrario Jennifer , Kumer Jeffrey , Howlett Anthony , Silverman Jeffrey 
Published: October 2019

Abstract
SNS-595 is a novel naphthyridine analog, a class of compounds not previously used for cancer treatment. SNS-595 is currently in an escalating-dose phase 1 trial in acute leukemia and several phase 2 studies in solid tumors. SNS-595 has a unique mechanism of action; causing double-strand breaks during S phase that are solely repaired through a DNA-PK-dependent pathway. This damage induces DNA damage-repair signals through both p53 and p73 pathways during DNA synthesis and is accompanied by a rapid onset of apoptosis and an irreversible G2 arrest. This mechanism suggests that SNS-595 could interact in combination favorably with other DNA damaging agents that utilize different mechanisms of damage signaling and repair. SNS-595 demonstrates potent anti-proliferative effects on human leukemic cell lines in vitro and is active in LM-3 Jck and CCRF-CEM hematologic xenograft models. Previously, we have shown that administration of SNS-595 results in a dose dependent loss in bone marrow cellularity and reduction in circulating neutrophils in mice (Proc. Amer. Assoc. Cancer. Res.47: 4726, 2006). These data suggest that SNS-595 activity in bone marrow and circulating blood may provide a therapeutic rationale for the treatment of acute leukemias and advanced chronic myelogenous leukemia. In this study we evaluated the effects of SNS-595 on peripheral white blood cells and bone marrow cellularity as a single agent and in combination with cytarabine (Ara-C) and daunorubicin (DNR). SNS-595 dosed once a day at 10 mg/kg IV as a single agent and Ara-C dosed three times a day as a single agent at 20 mg/kg SC, on day 0 and 4, resulted in 44% and 12% reductions in cellularity, respectively. In contrast, combination dosing of SNS-595 once a day at 10 mg/kg IV with Ara-C dosed three times a day at 20 mg/kg SC resulted in a 93% reduction in cellularity. Normal cellularity recovered on Day 12 (8 days post last dose). Furthermore, the SNS-595/Ara-C combination reduced cellularity more than Ara-C dosed at the MTD of 60 mg/kg three times a day SC (42% reduction in cellularity). Circulating leukocyte levels were also reduced including neutrophils that dropped from 1359 cells/ml to 587 cells/ml for SNS-595 dosed at 10 mg/kg IV and 1212 cells/ml for Ara-C dosed three times a day at 20 mg/kg SC on day 8. The co-administration of these two doses resulted in a near elimination of circulating neutrophils (29 cells/ml). Leukocyte counts subsequently returned to normal levels by Day 18 (14 days post last dose). In conclusion, co-administration of SNS-595 and Ara-C reversibly ablates murine bone marrow cells and reversibly depletes circulating neutrophils. These data indicate that SNS-595 has the potential to combine effectively with Ara-C for the treatment of acute leukemias and suggests that additional studies in patients with advanced hematologic malignancies are warranted.
Loss of Heterozygosity (LOH) of the NUP98 Gene Is an Adverse Prognostic Factor in Acute Myeloid Leukemia (AML).
Authors: Plasilova Magdalena , Ommen Hans B. , Jelinek Jaroslav , Issa Jean-Pierre , Riedel Elyn R. , Mathew Susan , Chadburn Amy , Zhou Pengbo , Hokland Peter , Moore Malcolm A.S. 
Published: October 2019

Abstract
The NUP98 gene on chromosome 11p15 encodes a 98kDa protein component of the nuclear pore complex that is involved in the nucleocytoplasmic transport of proteins and RNAs. Chromosomal translocations creating NUP98 fusion genes have been described in various hematologic malignancies including AML and myelodysplastic syndromes (MDS). The molecular mechanisms involving NUP98 gene locus and its function in leukemogenesis remain unknown, however, frequent allelic loss at the 11p locus has been reported in solid tumors and AML. We have evaluated NUP98 gene disruption by LOH in AML subtypes and correlated LOH with clinical outcomes including disease relapse and survival rates. A total of 101 patients with AML and 49 with MDS treated between 2002–2006 were evaluated for LOH at five markers in and around the NUP98 gene. We found a high frequency of 11p15 LOH of the NUP98 region in patients with overt AML (32/101) and a lower frequency in preleukemic MDS patients (4/49). The median follow-up for survivors was 26 months (range 15–43). Patients with NUP98 LOH had a significantly decreased overall survival as compared to patients without NUP98 LOH (median survival 4 and 13 months, respectively, p=0.007). In the subset of patients with no evidence of disease after treatment (n=57), the presence of NUP98 LOH was significantly associated with a decreased disease free interval (5 months vs. 24 months, p <0.0001). The NUP98 disruption was not associated with age, gender, cytogenetic findings, FAB subtype, FLT3-ITD status, prior history of MDS, WBC or platelet counts as confirmed by multivariate statistical model. We did not observe the silencing of the NUP98 gene by methylation of its promoter compared to the p57 gene, located on the same chromosome. In addition to LOH, we screened for chromosomal translocations involving the NUP98 region. In one AML patient we found both NUP98-HOXA9 translocation and LOH. By using the NUP98 antibody that detects both wild type and fusion protein, we found a significantly impaired localization of NUP98 protein and the presence of NUP98 co-localization aggregates within both the nucleus and cytoplasm of one patient, which indicated both NUP98-HOXA9 translocation and LOH. In summary, NUP98 LOH is associated with a worse clinical outcome for AML patients. The presence of NUP98 LOH supports the hypothesis that NUP98 allelic loss may be an important event in de novo leukemogenesis, when leukemia develops after MDS. NUP98 translocations associated with NUP98 fusions contribute to leukemogenesis, particularly in association with NUP98 LOH.
Novel Leukemia Associated Immunophenotype (LAIP) Absent from Normal and Regenerating Bone Marrow Identified by Multiparameter 6-Color Flow Cytometry.
Authors: Guyotat Denis , Olaru Daniela , Flandrin Pascale , Nadal Nathalie , Campos Lydia 
Published: October 2019

Abstract
Flow cytometry analysis of minimal residual disease (MRD) in acute myeloid leukemia (AML) is based on the detection of aberrant phenotypes responsible for the relapse. Until now, all studies were performed by 3 or 4 color immunostaining, allowing the identification of LAIP in 80% of cases. Moreover, no data is available regarding the existence of such phenotypes in regenerating bone marrow. The new generation of cytometers allows the study of 8 parameters that permit a better distinction of malignant from normal phenotypes. In our study we analyzed 20 bone marrow samples from allogeneic donors, 20 ALL regenerating bone marrows after chemotherapy and 53 AML samples at diagnosis. Multiparameter 4 colour and 6 colour flow cytometry was used in order to define antigen combinations which are totally absent or present at very minimal levels in normal and regenerating hematopoiesis. “Blast cells” were gated according to CD45/SSC properties.For the first time we describe by 6 color flow cytometry 47 phenotypes totally absent from “blasts” gate in all normal bone marrow (ex: CD34+DR−117+33−15+, CD34+38+33−56+19−, CD14−DR+4+11B+64+). Another 41 phenotypes were identified as presents at a frequency < 0,05% of total cells (ex: CD34+DR+117−33+15+, CD14−DR+4+11B+64−, CD34+65−56+4−16−). There was no significant difference between normal and regenerating marrows. The 4 color panel of moAbs allowed us to identify only 30 phenotypes presents at a frequency < 0,05% of total cells (ex: CD34+33−13+, CD34+117+11b+, CD34+DR−13+). 53 AML at diagnosis were studied using 6 color immunophenotyping and 58 % of phenotypes described as aberrant or infrequent in normal myeloid hematopoiesis were found in at least one AML at diagnosis in more than 1% of total cells. All AML cases show at least one LAIP but frequently we observed more than one LAIP blast subpopulation in the same sample. Some examples of LAIP observed are CD34+ 38+ 33+ 56+ 19−, CD34+ 38+ 33+ 56− 19+, CD34− DR− 117+ 33+ 15−. In conclusion our results shows that (1) the ability to clearly distinguish leukemic from the healthy cells is considerably increased by 6 color approach (8 parameters analyzed) than 4 color. (2) Furthermore that these aberrant or infrequent phenotypes in normal or regenerating bone marrow samples are identified in AML cases and can be utilized in AML minimal residual disease study. (3) Knowledge of the expression of different markers in normal hematopoietic development provides a frame of reference for identification of abnormal differentiation patterns.
Interaction of the Leukemogenic CALM/AF10 Fusion Protein with the Hematopoietic Key Regulator Ikaros.
Authors: Greif Philipp A. , Tizazu Belay , Kremmer Elisabeth , Krause Alexandre , Bohlander Stefan K. 
Published: October 2019

Abstract
The focus of our research group is the study of the t(10;11)(p13;q14) translocation that leads to the fusion of the proteins CALM and AF10. This translocation can be found in acute lymphoblastic leukemia (ALL), acute myeloid leukemia (ALL) and also in malignant lymphomas. In some patients the t(10;11) is the only cytogenetic abnormality which indicates that the CALM/AF10 fusion is a causal event during leukemogenesis. Previous studies of our group have shown that the expression of CALM/AF10 in hematopoietic stem cells triggers the development of an aggressive leukemia in a murine bone marrow transplantation model. CALM (Clathrin Assembly Lymphoid Myeloid leukemia gene) has a function in Clathrin mediated endocytosis. AF10, a putative transcription factor with a PHD-Motive (Plant Homeo Domain) and a Leucine Zipper domain, was initially identified as fusion partner of MLL. The underlying mechanism of CALM/AF10 dependent leukemogenesis, however, remains mostly unknown. Recently we could show that AF10 interacts with the transcription factor Ikaros (ZNFN1A1) in yeast-two-hybrid assays. Interestingly, Ikaros is a key regulator of hematopoesis, required for normal differentiation and proliferation of B- and T-lymphocytes. The structure of the protein is characterized by a DNA-binding and an oligomerisation domain. Through interaction with many factors in the cell nucleus, Ikaros can act both as activator and repressor of transcription. In various forms of ALL as well as chronic myeloid leukemia (CML) an aberrant expression pattern of Ikaros has been found. In a murine model the expression of a dominant negative isoform of Ikaros causes leukemias and lymphomas. Using various AF10 deletion mutants in the yeast, the Ikaros interaction domain of AF10 was mapped to the Leucine Zipper domain of AF10 which has also been shown to be required for malignant transformation by the MLL/AF10 fusion protein. Overexpression of fluorescently labelled proteins reveals a similar distribution pattern of AF10 and Ikaros in the nucleus, whereas in the presence of CALM/AF10 Ikaros appears to be localized predominately in the cytoplasm. The interaction between AF10 and Ikaros has been confirmed by GST-pull-down assays. In order to further study this interaction and its role in leukemogenesis we have raised monoclonal antibodies against the C-terminus of AF10. These antibodies are currently established for Western Blot analysis and Immunoprecipitation experiments. Reporter gene assays are carried out to measure the impact of CALM/AF10 on Ikaros’ function as repressor or activator of transcription. These studies may provide new insights into the mechanism of CALM/AF10 induced leukemia and thereby facilitate the development of new therapies.
Malignant Cells in the Marrow and Blood of Patients with Hematopoietic Malignancies Have Higher Mitochondrial Membrane Potential as Measured with the Potentiometric Dye JC-1.
Authors: Gardner Jeffrey R. , Zhang Rong H. , Rose Ruth , McKenzie Sue , Maslak Peter , Heaney Mark L. 
Published: October 2019

Abstract
Background: Immunophenotyping is an important method to define hematopoietic malignancies, but used alone, its ability to provide functional information about the malignant cells is limited. JC-1 is a fluorescent dye used to measure mitochondrial membrane potential in cells. We have developed a flow cytometric assay using JC-1 in conjunction with standard cell surface markers to characterize clinical samples from patients with hematologic malignancies.
Methods: Ficoll-purified cells derived from the blood or marrow were stained with JC-1, and analyzed at 530 nm and 590nm to assess mitochondrial mass and mitochondrial membrane potential, respectively. Malignant and normal cell populations were assigned and gated by analysis of forward scatter and side scatter. Gating in this manner identified energetically discrete cell populations confirmed by back gating analysis.
Results: To date we have measured the mitochondrial membrane potential from the bone marrow or peripheral blood of 3 normal individuals and 22 patients with acute and chronic leukemias and lymphoma involving the marrow. Samples have been analyzed from AML (6), ALL (3), CML- chronic phase (2), CLL (5), mantle cell lymphoma (3), diffuse large B-cell lymphoma (1) and acute biphenotypic leukemia (2). Compared with samples derived from normal individuals, malignant cells have a different energetic signature, and in nearly all instances, a substantially higher mitochondrial membrane potential. The mitochondrial membrane potential of malignant cells was 5.5 times higher (range 2.15–12) than normal cells within the same samples in 19 of 20 specimens (given the overlap in cell populations, CML samples were excluded and 1 CLL sample had a mitochondrial membrane potential that was the same as the normal population). Mitochondrial membrane potential is also higher in malignant cells compared with peripheral blood and marrow cells from normal individuals. While cells derived from patients with acute leukemias appear to be energetically homogeneous, cells from both patients with CML and 4 of 5 patients with CLL had at least 2 energetically discrete subpopulations despite being cytogenetically homogeneous (in the case of the CML samples) or immunophenotypically homogenous (in the case of the CLL samples).
Conclusions: JC-1 staining can be performed reliably in concert with immunocytochemistry and provides insight into the metabolism of malignant hematopoietic cells. Preliminary data indicate that malignant cells from patients with leukemia and lymphoma have a high mitochondrial membrane potential which may reflect altered oxidative metabolism. This may serve as a metabolic signature for monitoring minimal residual disease or assessing the effect of therapeutic agents on functional status of malignant populations.
Rituximab-Mediated Upregulation of PTEN Expression and Inhibition of Both the PI3K/AKT Pathway and Pleitrophin (PTN) Expression in B-NHL: Roles in Cell Growth Inhibition and Chemosensitization.
Authors: Suzuki Eriko , Chen Haiming , Baritaki Stavroula , Vega Mario I. , Gordon Melinda , Schiller Gary J. , Berenson James , Bonavida Benjamin 
Published: October 2019

Abstract
We have recently reported that rituximab treatment of B-NHL cell lines, like Ramos, inhibited the PI3K/AKT signaling pathway and downregulated Bcl-xL expression. The role of the AKT pathway in chemosensitization was corroborated by treating Ramos cells with the AKT inhibitor, LY294002, and resulted in sensitization of the cells to drug-induced apoptosis. We have investigated a potential underlying mechanism responsible for the rituximab-mediated inhibition of the AKT pathway. PTEN (phosphatase and tensin homologue deleted on chromosome 10) is a tumor suppressor phosphatase and functions as a negative regulator of the PI3K pathway through its phosphatase activity. We hypothesized that rituximab may upregulate PTEN expression and thus, inhibiting the AKT pathway. Treatment of Ramos cells with rituximab (20μg/ml for 20h) resulted in significant upregulation of PTEN expression (as assessed by both Western and RT-PCR). Time kinetic analysis showed that PTEN is upregulated as early as 6–9h post rituximab treatment. In addition, since rituximab inhibits cell proliferation and cell growth, we have examined the effect of rituximab on the expression of the growth factor pleitrophin (PTN). PTN is a heparin-binding and secreted growth differentiation factor that mediates various functions such as cell motility and migration, survival, growth and differentiation. Treatment of Ramos cells with rituximab inhibited PTN expression as early as 12h post treatment. The present findings suggested that rituximab-mediated induction of PTEN expression and inhibition of both the AKT pathway and PTN epxression may be interrelated and play an important role in rituximab-mediated cell growth inhibition and chemosensitization. A recent report by Li et al., (JBC, 281:10663,2006) demonstrated that PTEN null cells exhibited upregulation of PTN expression and activation of the PI3K/AKT pathway. Further, inhibition of PTN resulted in inhibition of the AKT pathway, thus establishing a feedback mechanism. Our findings with rituximab are consistent with the Li’s findings’. The mechanism by which rituximab inhibits PTN expression is not clear. Reported studies have implicated the role of AP-1 in PTN transcription and in agreement, our findings have also demonstrated that rituximab inhibits AP-1. Overall, the present studies suggest novel targets modified by rituximab namely, PTN and PTEN, which can be considered for therapeutic intervention in the treatment of both rituximab-sensitive and rituximab-resistant tumors.
Polymorphisms of Thymidylate Synthase in the 5′- and 3′-Untranslated Regions Associated with Risk of Non-Hodgkin’s Lymphoma.
Authors: Kim Hee Nam , Tran Huong Thi Thanh , Lee Il-Kwon , Kim Yeo-Kyeoung , Yang Deok-Hwan , Lee Je-Jung , Shin Myung-Geun , Kook Hoon , Hwang Tai Ju , Park Moo Rim , Jo Deog Yeon , Won Jong Ho , Kim HyeoungJoon 
Published: October 2019

Abstract
Thymidylate synthase (TS) catalyzes the conversion of dUMP by 5,10-methylenetetrahydrofolate to dTMP in DNA synthesis. Polymorphisms in the untranslated regions(UTRs) of TS, which may modulate TS transcription and expression, have been associated with susceptibility to several malignancies. In this study, to evaluate the association with TS the 28-bp tandem repeat(2R→3R) and the 6-bp deletion(6 bp-) and susceptibility to non-Hodgkin’s lymphoma(NHL), large-scale population-based case-control study was conducted in Chonnam National University Hospital between Mar 1997 and Feb 2006. 553 patients with histologically comfirmed lymphoma and 1,324 controls were evaluated. The cases consisted of 275 diffuse large B-cell lymphomas (DLBCL), 109 T-cell lymphomas and 169 unclassifiable lymphomas. TS 2R2R genotype was significantly associated with increased risk for NHL and T-cell lymphoma, but not for DLBCL. Using subjects with the TS 3R3R as a reference group, the OR of TS 2R2R was 2.00 (95% CI 1.21–3.31, p=0.007) for NHL and 3.30 (95% CI 1.52–7.17, p=0.003) for T-cell lymphoma. The association was 1.65 fold higher and more evident for T-cell lymphoma than NHL. However, there was no significant association of TS 6bp- with NHL.
In conclusion, theses results suggest that TS (2R→3R) may play an important role in the pathogenesis of NHL, and that DNA synthesis may play a crucial roles in the pathogenesis of specific NHL subtypes.