bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Avidity Leukemia-Associated Antigen-Specific CD8+ T Cells Preferentially Localize to the Bone Marrow in Patients with Myeloid Malignancies.
Authors: Melenhorst J. Jopseph , Scheinberg Phillip , Chattopadhyay Pratip K. , Gostick Emma , Roederer Mario , Hensel Nancy F. , Douek Daniel C. , Barrett A. John , Price David A. 
Published: October 2019

Abstract
Both acute and chronic myeloid leukemias (AML and CML) and myelodysplastic syndromes (MDS) over-express and present self-antigens such as the HLA-A*0201-restricted proteinase 3 (PR1) and Wilm’s tumor-1 (WT1) epitopes, making these leukemia-associated antigens selectively amenable to immunotherapeutic intervention. Here, we examined the antigen avidity properties of circulating and bone marrow-resident CD8+ T cells specific for PR1 and WT1 in patients with AML (n=11), CML (n=10) and MDS (n=3). A total of 19 bone marrow (BM) samples and 27 peripheral blood (PB) samples were studied both prior to and following stem cell transplantation (SCT). Cognate HLA-A*0201 tetramers with identical TCR docking platforms were produced using three distinct monomeric HLA-A*0201 complexes with differential coreceptor binding properties to dissect the avidity of antigen binding directly ex vivo:
“CD8-null” tetramers, which contain a compound D227K/T228A mutation in the a3 domain of the heavy chain that abrogates CD8 binding; wildtype tetramers; and, “CD8-enhanced” tetramers, which contain a Q115E mutation in the a2 domain of the heavy chain that moderately increases CD8 binding.
We have shown previously that CD8-null tetramers engage only high avidity antigen-specific CD8+ T cells; in contrast, CD8-enhanced tetramers can engage populations of antigen-specific CD8+ T cells with low avidities that fall below the threshold for detection with wildtype tetramers. Using these reagents, we developed a polychromatic flow cytometric panel that enabled the simultaneous assessment of phenotype, function and avidity within antigen-specific CD8+ T cell populations. Either PR1- and/or WT1-specific CD8+ T cells were identified in 12/19 BM samples and 6/27 PB samples. Notably, one of the pre-SCT samples contained only low avidity leukemia-associated antigen-specific CD8+ T cells; in contrast, all of the specific populations identified in the post-SCT samples engaged their cognate antigen with high avidity. In 5/7 patients, analysis of paired BM/PB samples revealed the presence of high avidity PR1- and/or WT1-specific CD8+ T cells confined almost exclusively to the BM. Phenotypic analysis demonstrated a mixture of central and effector memory cells in all cases, thereby confirming that these PR1- and WT1-specific CD8+ T cell populations were antigen-experienced. Thus, high avidity CD8+ T cells specific for leukemia-associated antigens are present in vivo and preferentially localize to BM in myeloid malignancies.
Increasing Functional Avidity of T Cell Receptor (TCR)-Redirected T Cells by Removing Defined N-Glycoslyation Sites in the Constant Domain of Introduced TCR Chains.
Authors: Kuball Juergen , Hauptrock Beate , Wolfl Matthias , Voss Ralf Holger , Strong Roland , Theobald Matthias , Greenberg Phil 
Published: October 2019

Abstract
Adoptive transfer of T lymphocytes transduced with a TCR to impart tumor reactivity has been reported as potential strategy to redirect immune responses to target cancer cells. However, the affinities of most TCRs specific for shared tumor antigens that can be isolated are usually low, in part reflecting the nature of the targeted tumor antigens which are self-proteins. Thus strategies that can increase the affinity or functional avidity of TCRs to be used in therapy to transduce T cells might be therapeutically beneficial. However, current strategies for increasing TCR affinity require extensive and usually random mutagenesis followed by screening the many derived mutations, and must be individualized for each TCR. Since glycosylation impacts the flexibility, movement, and interactions of surface molecules, we tested if removing conserved N-glycoslyation sites in the constant regions of TCR a or b chains can increase the functional avidity of T cells transduced with such modified TCR. We observed enhanced functional avidity and improved recognition of tumor cells by CD8 T cells harboring partially N-deglycosylated as compared to wild type (wt) TCR chains. T cells transduced with wt or N-deglycosylated TCR chains bound tetramer equivalently at 4°C, but tetramer-binding was enhanced at 37°C, reflecting predominantly reduced tetramer dissociation, suggesting an energy-dependent conformational change and/or enhanced clustering of N-deglycosylated TCR chains. The enhanced avidity was evident in the presence or absence of the CD8 co-receptor. This strategy was effective with murine and human TCRs specific for different antigens, and thus should be readily translated to TCRs with any specificity. Thus, transfer of partially deglycosylated TCR chains is a generally applicable strategy that can be used to increase functional avidity of TCR-transduced T cells.
Electrocardiographic Screening for Cardiac Iron in Thalassemia Major.
Authors: Detterich Jon A. , Miller Janelle , Coates Thomas D. , Wood John C. 
Published: October 2019

Abstract
Electrocardiographic abnormalities are common in Thalassemia Major patients as well as in animal models of iron overload. The relationship between these ECG abnormalities and the degree of cardiac iron overload has not been well characterized.
Hypothesis: Standard 12-lead ECG identifies preclinical cardiac iron deposition.
Methods: Fifty-four patients with Thalassemia Major underwent MRI quantification of cardiac iron within one month of a standard 12-lead ECG. Cardiac T2* measurements to quantify iron were performed using a validated multiecho gradient-echo sequence performed on a 1.5 Tesla General Electric CVi scanner. The PR, QRS, QT, and QTc durations as well as P-wave, T-wave and QRS axes and heart rates were measured. Normative data was derived from 20 control patients without detectable cardiac iron (T2* > 20 ms) and age-appropriate norms were created for each ECG criteria. Z-scores for the ECG parameters were then calculated for 34 patients having detectable cardiac iron (T2* < 20ms).
Results: ECG parameters varied significantly with age, with correlation coefficients ranging from 0.39 (QTc interval) to 0.66 (PR interval). Cardiac iron was associated with lower heart rates (Z=−0.44, p=0.06), QTc prolongation (Z=0.48, p=0.04) and leftward shift of the P and T wave axes [P-Axis (Z = −1.53, p<0.001); T-Axis (Z= −1.91, p<0.001)]. In total, 31 of 34 pts with cardiac iron had one or more ECG abnormalities (|Z|>2), compared to only 7 of 20 control pts (p<0.0001). Subjective ECG review was consistent with Z-score. The most common abnormalities associated with cardiac iron were non-specific ST-T wave changes (n = 15), sinus bradycardia (n=4), symmetric T-wave inversions (n = 4) and LVH (n = 4). The presence of any of these findings on ECG predicts detectable cardiac iron with a sensitivity and specificity of 68% and 85%. A combined metric of PR prolongation (Z>2), left shift of P or T axis (Z<–2), bradycardia, LVH, ST changes, or symmetric T-wave inversions produced a sensitivity of 94% and specificity of 75% for detectable cardiac iron.
Conclusions: Cardiac iron overload produces characteristic abnormalities in atrial conduction and ventricular repolarization. ECG may be an effective and inexpensive screening modality for cardiac iron overload.
Figure Figure Figure Figure
Long-Term Effects of Combined Chelation Therapy on Glucose Metabolism of Thalassemic Patients.
Authors: Farmaki Kalistheni , Angelopoulos Nicholas , Berdoukas Vasilios , Tsoumari Ioanna , Pappa Christina , Pappagianni Kiki 
Published: October 2019

Abstract
• The incidence of impaired glucose tolerance and diabetes in thalassemiamajor patients varied from 9% to 15%, depending on the age of assessment and intensity (and compliance) of chelation and transfusion. It is uncertain whether early assessment and tailored chelation can prevent diabetes and preserve pancreatic reserve. There are now reports of endocrine improvements with intense chelation in regards to glucose metabolism which are limited to 3 years of follow up. However, whether the pancreas may regenerate or remodel even with reduction in hemosiderosis is unknown and questions have arisen whether these are lasting improvements reflecting an overtime advantage earned by the intensification of chelation. The aim was to determine the long-term effects of combined chelation therapy on glucose metabolism in beta-thalassaemic patients • From January 2001 to October 2003, 42 thalassemic patients (initially treated with deferoxamine DFO monotherapy) were gradually switched to an individually tailored combined regimen with DFO and deferiprone. Glucose metabolism characteristics were evaluated by Oral glucose tolerance test (OGTT). Each patient was assessed separately before initiating combined therapy, and all patients were thereafter yearly reassessed (June 2005, June 2006 and June 2007). Full biochemical data (4 consecutive measurements) were available in 30 patients (3 got pregnant during this period, 5 denied repeated OGTT and 4 patients with severe and sustained hyperglycaemia started antidiabetic drugs after the second assessment in 2006). Insulin sensitivity and beta-cell function were assessed by calculated indices, using the most widely applied insulin sensitivity index - the homeostasis assessment model (ISI HOMA) which is based on fasting glucose and insulin alone. The area under the curve (AUC) was also calculated for estimating integrated response during OGTT for both glucose and insulin. Significant variations over time for each parameter were examined with ANOVA (general linear model) for repeated measurements. Ferritin levels were significantly decreased (P<0.01),AUCglu decreased (P=0.002)and SCHoma increased (P=0.004) as illustrated in Table 1. 70% of patients had abnormal glucose response during the first OGTT (diabetic response, Impaired glucose tolerance or impaired fasting glucose, according to the latest criteria of the American Diabetes Association published in September 2005). In May 2007, only 20% exhibited abnormal glucose response with the same provocative test (P<0.001,non-parametric McNemar test). Our 6-year follow-up demonstrates that use of combined chelation therapy continues to be of benefit in terms of glucose metabolism in thalassemic patients.
Parameters (Mean value) 1st assessment 2005 2006 2007 Ferritin 2960 551 585 629 SCHoma 133.4 215.6 200.6 209.9 ISI Homa 1.101 0.964 1.085 0.886 AUCglucose 18217 16166 16526 15655
The Synthetic Hest Shock Protein (Hsp) 90 Inhibitor EC141 Induces Degradation of the Bcr-Abl p190 Protein and Apoptosis of Philadelphia Chromosome (Ph)-Positive Acute Lymphoblastic Leukemia (ALL) Cells.
Authors: Ferrajoli Alessandra , Wang Yongtao , O’Brien Susan M. , Faderl Stefan H. , Harris David M. , Van Quin , Hallevi Inbal , Liu Zhiming , Koch Patricia E. , Sensintaffar John , Burrows Francis , Kantarjian Hagop M. , Keating Michael J. , Estrov Zeev 
Published: October 2019

Abstract
High dose chemotherapy of Ph+ ALL is rarely curative and clinical responses to protein kinase inhibitors have been transient. Although new regimens combining chemotherapy with Bcr-Abl kinase inhibitors improve survival, the long-term prognosis of patients with Ph+ ALL remains guarded. Thus, novel therapeutic strategies are needed. Hsp90 is a ubiquitous molecular chaperone protein required for the folding, activation and assembly of mediators of signal transduction, cell cycle control, and transcription regulation. The Hsp90 inhibitor EC141 (Biogen Idec, Inc.) blocks the chaperone activity of Hsp90 and induces proteasomal degradation of it’s client proteins. Because Hsp90 is a chaperone of Bcr-Abl we investigated the activity of EC141 against the Ph+ ALL B-cell lines Z-119, Z-181 and Z-33 (Estrov et al. J Cell Physiol166: 618, 1996; Leukemia10:1534, 1996). First we studied the effect of EC141 on Hsp levels in Ph+ ALL cells. EC141 (50 nM) down-regulated the protein levels of Hsp90 and upregulated those of Hsp70. Then, the effect of EC141 on the proliferation of Ph+ ALL cells was evaluated using the MTT assay. EC141 inhibited the growth and metabolic activity of Z-119, Z-181 and Z-33 Ph+ ALL cells in a dose-dependent manner at concentrations ranging from 1 to 100 nM. Similar results were obtained with primary bone marrow cells from patients with Ph+ ALL. Using the ALL blast colony culture assay we found that EC141 inhibited the proliferation of marrow-derived ALL colony-forming cells in a dose-dependent fashion. To explore the mechanism of action Z-181 were incubated cells with increasing concentrations of EC141; immunoprecipitation and Western immunoblotting were used to detect changes in cellular protein levels. EC141 degraded the Bcr-Abl p190 protein and inhibited the phosphorylation of CrkL in a dose-dependent manner. Furthermore, exposure of Z-181 cells to EC141 resulted in a time- and dose-dependent activation of procaspase 3, cleavage of poly (adenosine diphosphate-ribose) polymerase and apoptotic cell death as assessed by Annexin V. Taken together, our data suggest that EC141 degrades the Bcr-Abl p190 protein, inhibits proliferation, and induces apoptosis of Ph+ ALL cells. Additional studies aimed at investigating the in vivo activity of EC141 in Ph+ ALL are warranted.
Oncogenic NK-Like Homeodomain Proteins Inhibit Etoposide-Induced Apoptosis in T-ALL Cell Lines by Activation of the Polycistronic miR-17-92 Transcript.
Authors: Nagel Stefan , Venturini Letizia , Meyer Corinna , Drexler Hans G. , MacLeod Roderick A.F. , Scherr Michaela 
Published: October 2019

Abstract
Homeobox genes of the NK-like familiy, including TLX1, TLX3 and NKX2-5, are ectopically activated in T-cell acute lymphoblastic leukemia (T-ALL) cells mostly via chromosomal aberrations. The pathologic function of these closely related genes is still unclear. Here we analyzed their effect on the C13ORF25 gene, containing the miR-17-92 cluster. Micro RNAs (miRNAs) are a class of small non-coding RNAs which are part of an evolutionarily highly conserved intracellular mechanism, regulating gene expression by hybridization to complementary sequences usually located in the 3′untranslated region of coding transcripts. The primary transcripts (pri-mRNA) are processed to short mature miRNAs, mediating either inhibition of mRNA translation or mRNA cleavage. Aberrant expression of specific miRNAs is involved in oncogenesis as recently described for several human malignancies. The miR-17-92 polycistron encodes miRNAs which decrease E2F1 protein expression. Transcription of both E2F1 and miR-17-92 is induced by MYC, itself a target of E2F1, generating a highly regulated interactive network. Depending on the cellular context, E2F1 performs conflicting tasks by triggering proliferation or inducing apoptosis. We investigated the expression of the miR-17-92 cluster in T-ALL cell lines. Real-time RT-PCR analysis of both miR-17-92 pri-mRNA and mature miRNAs revealed different expression levels in these cells, suggesting a possible implication of the NK-like homeodomain proteins in the regulation of the miR-17-92 cluster in T-ALL. HELA cells transfected with TLX1 or NKX2-5 expression constructs showed elevated miR-17-92 pri-mRNA expression, demonstrating an activating effect. Lentiviral-mediated overexpression of NKX2-5 in the T-ALL cell line MOLT-4 consistently showed increased miR-17-92 pri-mRNA levels and decreased E2F1 protein amounts. For functional analysis of these downstream targets, another T-ALL cell line (PEER) was lentivirally transduced with expression constructs for either miR-17-92 or E2F1, resulting in reduced or elevated E2F1 protein levels, respectively. Overexpression of miR-17-92 or E2F1 did not significantly influenced the cell proliferation. However, induction of apoptosis by treating these cells with etoposide, an inhibitor of topoisomerase II, indicated that overexpression of miR-17-92 and E2F1 resulted in enhanced and reduced cell viability, respectively, as analyzed by MTT assay. In summary, these data indicate an activatory effect of oncogenic NK-like homeodomain proteins on miR-17-92 expression, reducing E2F1 protein levels and thereby enhancing survival of leukemic T-cells.
Frequent Mitochondrial DNA Mutations and Polymorphisms in Long-Term Survivors of Childhood Acute Lymphoblastic Leukemia.
Authors: Lipshultz Steven E. , Walker Vernon E. , Torres Salina M. , Walker Dale M. , Barry Elly , Miller Tracie L. , Scully Rebecca E. , Sallan Stephen E. 
Published: October 2019

Abstract
Progressive myocardial dysfunction, which can lead to cardiomyopathy, congestive heart failure, and sudden cardiac death, is a well-recognized late effect of several agents used in the treatment of childhood cancer. While the mechanism of this damage is not yet fully characterized, mounting data from rodent models implicate treatment-induced mitochondrial DNA (mtDNA) mutations as one potential mechanism of late cardiotoxicity. In the current study, the Dana-Farber Cancer Institute Acute Lymphoblastic Leukemia (ALL) Consortium collected peripheral blood mononuclear cell samples from 93 long-term ALL survivors who were 4 or more years post-doxorubicin and other multi-agent therapy including asparaginase, corticosteroids, vincristine, and methotrexate, as well as radiation therapy. Data from healthy newborn children (n=45) represented a negative control and data from children receiving highly active antiretroviral therapy (HAART) (mean age=11.3 years; SD=2.61; n=51) provided a positive control for mtDNA mutations. Maximum cumulative doxorubicin dose varied among patients by treatment protocol (median=300 mg/m2; range 45 mg/m2 to 470 mg/m2). Median age at treatment was 4.5 years (range=0.5 to 20.8 years) and at mtDNA screening, 14.9 years (range=6.0 to 41.1 years). The mitochondrial tRNA genes and flanking regions were screened via PCR-based denaturing gradient gel electrophoresis (DGGE). Preliminary data showed 47 confirmed polymorphisms or mutations in 39 of 93 ALL survivors screened (42%), occurring in PCR products from 6 of 13 primer sets. The mutation incidence in HIV positive controls receiving HAART was 35 changes in 25 of 51 patients (49%). To date, the negative control population data suggest the occurrence of very few to no polymorphisms or mutations. Most mtDNA changes in ALL survivors were distinct from those in children receiving HAART, and included some sequence variants with suggested pathogenic characteristics. Analysis of cardiac function is ongoing. These data suggest that childhood ALL and its treatment may lead to mutations, over-expression of rare polymorphisms, and the induction of persistent changes that when spontaneously occurring have been associated with clinically significant cardiac effects. Conclusive evidence that doxorubicin-containing multi-agent therapy leads to persistent mtDNA mutations fundamental to cardiac dysfunction might allow for the isolation and prevention of these cardiotoxic effects.
Dynamic In Vivo Imaging Reveals That Leukemia-Induced Changes in the Bone Marrow Microenvironment Alter Mechanisms of Metastasis.
Authors: Colmone Angela , Krishnamoorthy Veena , Sipkins Dorothy A. 
Published: October 2019

Abstract
Tissue microenvironments have been shown to critically regulate cancer cell survival and proliferation. Conversely, while tumor growth can induce neovascularization, the impact of other tumor-induced changes in the microenvironment are less well understood. Here we utilize a xenograft model of Nalm-6 pre-B acute lymphoblastic leukemia (ALL) in SCID mice to examine how tumor growth alters the bone marrow (BM) microenvironment. Using dynamic confocal and multiphoton in vivo imaging, we find that tumor growth dramatically down-regulates expression of the chemokine SDF-1 in the BM microvasculature in areas of leukemic proliferation. SDF-1 has been shown to play a key role in cancer cell metastasis for numerous cell types including Nalm-6, and directs initial Nalm-6 homing to specific SDF-1-positive vascular beds. In contrast, we found that Nalm-6 introduced in mice previously engrafted with leukemia home to SDF-1-negative vasculature, predominantly at the advancing tumor margin. Furthermore, inhibition of chemokine signaling by pertussis toxin pre-treatment of Nalm-6 cells demonstrates that Nalm-6 homing in engrafted mice is chemokine-independent. In summary, these findings suggest that leukemic growth profoundly alters the mechanisms underlying the metastatic process by inducing changes in the host vascular microenvironment. These changes may increase the efficiency of the metastatic process and/or the advancement of the tumor margin. Therapies directed at blocking tumor metastases, therefore, may need to be tailored according to tumor stage.
Genetic Profiling of Adult Acute Lymphoblastic Leukemia Cells by Single Nucleotide Polymorphism Oligonucleotide Microarray.
Authors: Okamoto Ryoko , Ogawa Seishi , Akagi Tadayuki , Kato Motohiro , Sanada Masashi , Miller Carl W. , Kawamata Norihiko , Haferlach Claudia , Haferlach Torsten , Koeffler H. Phillip 
Published: October 2019

Abstract
Acute lymphoblastic leukemia (ALL) is a malignant disease of bone marrow cells, resulting from accumulation of genetic alterations of these cells. We analyzed 74 adult ALL samples by single-nucleotide polymorphism DNA microarray (SNP-Chip) using the new algorithm AsCNAR (allele-specific copy-number analysis using anonymous references). 71 samples (96%) showed genomic abnormalities in a mean 4.5 chromosomes including duplications, deletions and loss of heterozygosity with normal copy number [we call this uniparental disomy (UPD)]. About 25% of samples had a normal karyotype but each had genomic changes detectable by SNP-Chip. Importantly, 21 cases (28%) had UPD, and 29% of these had 9p UPD. Other genomic defects included deletions of p16INK4A in 18 cases (24%), deletions of ETV6 in 7 cases (9%), and hyperdiploidy (>50 chromosomes) in 3 cases (4%). In contrast, we also analyzed 399 pediatric ALL samples and deletions occurred in p16INK4A (28%) and ETV6 (22%) and 29% cases had hyperdiploidy. Hyperdiploidy is associated with a good prognosis and occured much more frequency in pediatric ALL (29%) than adult ALL (4%) which may in part explain the better prognosis in pediatric ALL compared to adult ALL. Also, small copy number changes were detected in adult ALL including deletion of B-cell differentiation genes: EBF (4 cases, 5%), Pax5 (5 cases, 7%) and IKZF (Ikaros) (8 cases, 11%), as well as, deletion of miR-15a and miR-16-1 (2 cases, 3%), which is often found in CLL. Amplification of Rel and BCL11A occurred in one case and amplification of Akt2 occurred in another case. Moreover, we found PAX5/ETV6 fusion in one case (1%); in comparison, 14 of 399 pediatric ALL cases (4%) had PAX5 fusion genes. In summary, we discovered hidden abnormalities including small copy number change and UPD in adult ALL and identified differences between adult and pediatric ALLs. In the future, routine SNP-Chip analysis may provide novel subclassification criteria for ALL and identify unique therapeutic targets.