bluuebunny/crossref_metadata_2025_split huggingface dataset:
Different Number of AML1/ETO Transcripts in Single Leukemic Cell, Estimated by Combined Measurement of MRD by FISH and Real-Time PCR, Is a Powerful Predictor of Relapse.
Authors: Maeba Hideaki , Nishimura Ryosei , Kuroda Rie , Horisawa Toru , Saikawa Yutaka , Koizumi Shoichi 
Published: October 2019

Abstract
The t(8;21)(q22;q22) translocation is observed in about 40% of pediatric cases of AML M2. Although patients with t(8;21) AML have a relatively good prognosis, relapses still occur in about 30% cases. To predict relapse, several studies examining sequential quantitation of minimal residual disease (MRD) by real-time PCR after chemotherapy or BMT have been attempted. However, these studies have shown that only a very small number of AML1/ETO transcripts are detectable in most t(8;21) AML patients who maintain complete long-term remission (CR). A recent study clearly demonstrated the existence of nonmalignant stem cells with leukemia specific genes. In another study, the suppression of AML1/ETO by siRNA in vitro resulted in the increased expression of genes associated with myeloid differentiation as well as antiproliferative genes in both leukemic blasts and cell lines. This suggests that cells expressing lower level of AML1/ETO might be well-differentiated malignant cells with slower proliferation rates compared to those expressing higher levels of AML1/ETO. Taken together, we hypothesized that the translocated gene detected by PCR, even in long-term remission patients, might be derived from nonleukemic stem cells or well-differentiated leukemic cells. If we can estimate AML1/ETO transcripts in single cells possessing leukemic translocation genes in BM in CR, we can predict, with high reliability, whether early relapse would occur or not. To test this hypothesis, we simultaneously assessed MRD by FISH with locus-specific probes with higher sensitivity and by quantitative real-time PCR in BM samples obtained from seven pediatric patients with AML1/ETO during and after chemotherapy/BMT. We then evaluated the value which was calculated by dividing normalized AML1/ETO copies/μgRNA by the percentage of t(8;21)-positive cells by FISH (RQ-PCR/FISH), which ideally reflected actual number of AML1/ETO transcripts in single cell with leukemic translocation in BM cells. RQ-PCR/FISH of non-relapse patients ranged from 5.5 × 102 to 5.5 × 103 (mean 2.5 × 103 ) in BM in CR. In marked contrast, 8.0 × 103 to 1.8 × 105 (mean 5.9 × 104 ) was observed from the patients who finally relapsed. Indeed, we demonstrated that in some cases showing low value of RQ-PCR/FISH, the AML1/ETO was detected only in terminally differentiated basophils (CD34− CD203c+ ), not in stem cell fractions (CD34+ CD203c± ). In conclusion, we propose that RQ-PCR/FISH can be a powerful predictor of relapse, especially in patients with lasting MRD positive after chemotherapy/BMT.
Short Telomeres Combined with Low Telomerase Activity Are Associated with a Longer Survival in Patients with Acute Myeloid Leukemia.
Authors: Saada Veronique , Ba Loc Pierre Tran , Legeai Camille , Castaing Marine , Bourhis Jean-Henri , Raphael Martine , Bennaceur-Griscelli Annelise 
Published: October 2019

Abstract
Telomeres - the terminal regions of human chromosomes, and enzyme telomerase - a ribonucloprotein that synthesizes telomeric DNA onto chromosomal ends, have been thoroughly investigated as potential markers for the prognosis of various cancers including leukemia. However, it is important to consider both parameters and only few studies have investigated the prognostic value of these two combined biomarkers in patients with acute myeloid leukemia (AML). Our work was designed to determine the impact of telomere length together with telomerase activity (TA) on survival in patients with AML. In this current retrospective study, TA (reflected by the quantitative expression of the catalytic subunit of telomerase i.e the hTERT mRNA/18s RNA ratio measured by Q-RT-PCR) and telomere length (determined by southern blot analysis of terminal restriction fragments) were assayed in the bone marrow of 40 patients diagnosed with AML between 1999 and 2003 at Institute Gustave Roussy’s division of Hematology. The patients’ characteristics are shown on table 1. All patients were treated according to standard AML-type chemotherapy protocols. The median of TA (hTERT mRNA/18s RNA ratio) was 0.0458. TA was not detectable in 4 patients. The median of telomere length was 7.6 Kb (range: 3.5–11.2 Kb). No correlation was found between TA and telomere length. A negative correlation existed between telomere length and age (r= −0.42; p=0.0097). The Kaplan-Meier statistical method and logrank test were used for univariate survival analysis and the Cox proportional hazard regression models for multivariate survival analysis. In multivariate analysis, when adjusted for age (>= 50 years versus younger), cytogenetics findings (poor prognosis versus others) and the nature of leukemia (secondary versus de novo), improved survival was found in patients with a combination of short telomere length (<7.6 Kb) and weak TA (<0.09, cut off point separating the upper tertile) and the worse survival was found in patients with long telomere length (>=7.6 Kb) and high TA (>=0.09) (hazard ratio=9.91; 95% CI: 1.75–56.03; p=0.01). Our results suggest that the combination of telomere length and telomerase activity can be considered as an independent prognostic factor for survival in patients with AML.
Table 1: Patients characteristics Sex (no. of patients) * AML post solid tumor (n=7), post myelodysplastic syndrome (n=1), post chronic myeloid leukemia (n=1) M 18 F 22 Age (years) Median 50 Range 22–74 Leukocyte count (Giga/L) Median 24.2 Range 1.3–360 Bone marrow blast percentage Median 76.5 Range 20–99 FAB Classification (no. of patients) M0 6 M1 9 M2 5 M4–M5 12 M4Eo 3 M6 1 Biphenotypic AL 3 NK AML 1 Type of leukemia (no. of patients) De novo 31 Secondary 9* Prognosis (based on karyotype) Good 5 Intermediate 21 Poor 10 Missing 4
Elevated Fas Ligand and BA21 Serorecognition as Disease Correlates in Bone Marrow Failure Disorders: Taking Advantage of the LGL Leukemia Model.
Authors: Nyland Susan B. , Cuthbertson David , Loughran Thomas P. 
Published: October 2019

Abstract
Persistently expanded large granular lymphocytes (LGL) are found in bone marrow failure disorders such as pure red cell aplasia, myelodysplastic syndromes, aplastic anemia, paroxysmal nocturnal hemoglobinuria (PNH), and in LGL leukemia. Many of the characteristics of BMF diseases overlap and it is postulated they share a fundamental pathogenetic link. LGL leukemia represents the best characterized disease of LGL, and was used as a model to study pathogenic LGL proliferation in bone marrow failure diseases. LGL leukemia cells are characteristically resistant to Fas-regulated death, despite expressing high levels of Fas receptor and Fas ligand (FasL). Elevated FasL may cause the neutropenia that is observed in many LGL leukemia patients. A poorly understood feature of LGL leukemia is serorecognition of a discreet epitope derived from the HTLV envelope BA21 region. To query the common pathogenesis in all of the BMF disorders, FasL expression and BA21 seroreactivity levels were obtained for patients with bone marrow failure disease (n=87). The serum FasL levels as determined by antigen capture were inversely correlated with neutrophil counts regardless of disease subtype. A positive correlation was noted between FasL expression and lymphocytosis, basophile counts, and serum chloride mEgL (Pearson correlation p values 0.0621, 0.0224, 0.0465). Negative correlations for FasL included neutrophil count and serum albumin levels (p= 0.0333 and 0.0657 respectively). Initial data from an assay we designed to obtain standardized anti-BA21 IgG data revealed a strong negative correlation for BA21 IgG and FasL (−0.3668) for the PNH cohort. An additional moderately positive Pearson correlation for FasL and BA21 IgG was found only for the LGL leukemia group (0.1813), although all BMF groups demonstrated elevated IgG recognition of BA21 (n=78). In addition, FasL and BA21 IgG levels were most elevated in female patients. Our results suggest that FasL and BA21 IgG levels correlate with certain laboratory features of hematopoeitic inhibition as well as with patient gender. A potential utility in discriminating between bone marrow failure disease subtypes and determining treatment response potentials could also be realized with further study.
Abnormal CD34 Positive Cells Are Present in NPM+ Acute Myeloid Leukemia (AML) Samples at Diagnosis.
Authors: Martinez Clara M. , Bussaglia Elena , Hernandez Carmen , Estivill Camino , Ubeda Josep , Brunet Salut , Aventin Anna M. , Sierra Jorge , Nomdedeu Josep F. 
Published: October 2019

Abstract
Nucleophosmin (NPM) gene mutations are the molecular hallmark of a large primary AML subgroup of patients. NPM mutated cases are commonly associated with FLT3-internal tandem duplications which seem to confer an adverse prognostic meaning. Blasts from NPM+ leukemias have been described as CD34 negative.
Objective: To assess the presence of CD34 positive populations and their phenotypic profile in NPM mutated samples at diagnosis. To investigate whether there are differences between NPM/FLT3- and those with an associated FLT3-ITD.
Patients and methods: Cells from forty-three bone marrow de novo NPM+ AML (26 females/ 17 males) patients enrolled in AML-CETLAM protocols were analyzed at diagnosis by means of multiparameter flow cytometry (MFC). In 18 cases an associated FLT3-ITD was detected (NPM+/FLT3+ group). Immature antigenic markers were investigated by triple combinations of direct conjugated MoAbs to CD15, CD34 and HLA-Dr ; CD34, CD123 and HLA-Dr; CD34, CD33 and CD19; CD15, CD117 and CD45. Minimal residual disease studies (7 cases) were performed in samples in complete remission using flow cytometry and real-time PCR (ABIPRISM 7700).
Results: In all the patients we were able to detect an abnormal CD34 population. CD15 coexpression, abnormal light scatter patterns, CD117 clusterization, antigenic overexpression and abnormal CD123 expression were all detected in these cases. NPM+/FLT3+ patients had 2,24% CD34+ cells(0,12%–42%) whereas for NPM+/FLT3- cases the mean CD34+ value was 1,05% (0,1–92%)(n.s.). Sequential samples to test in parallel the abnormal immunophenotype and NPM transcripts by real-time PCR were available in 7 cases (5 NPM+/FLT3+ and 2 NPM+/FLT3-). Relapses were observed in two NPM+/FLT3+ cases (4% and 42% CD34+ cells at diagnosis) and 1 NPM+/FLT3- patient (0.1% CD34+ cells at diagnosis). No definite pattern of relapse could be established given that in some cases NPM rises preceded the detection of phenotypically abnormal cells.
Conclusions: NPM mutated AML patients may be mostly categorized as CD34 negative following standard flow-cytometry positivity thresholds. Nevertheless, the constant detection of immature abnormal cells (CD34+CD123+CD117++) may help to identify the leukemic stem-cell pool in NPM+ and FLT3+ leukemias. It remains to be investigated whether the size of this compartment has prognostic relevance in some groups of normal karyotype AML.
Comprehensive Analysis of Genetic Alterations in Acute Myeloid Leukemia According to the WHO Classification.
Authors: Ishikawa Yuichi , Kiyoi Hitoshi , Tsujimura Akane , Miyazaki Yasusi , Tomonaga Masao , Kuriyama Kazutaka , Miyawaki Syuichi , Naoe Tomoki 
Published: October 2019

Abstract
Acute myeloid leukemia (AML) is a heterogeneous clonal disorder of hematopoietic progenitor cells, and is thought to be the consequence of two broad complementation classes of mutations: those that confer a proliferative and/or survival advantage to hematopoietic progenitors, and those that impair hematopoietic differentiation and confer properties of self-renewal. To date, several genetic alterations, which are involved in the pathophysiology of the AML development, have been apparent, and some of them have been disclosed to have an impact on the clinical management. Therefore, it is required to establish the detailed classification of AML according to the genetic status. In this study, we comprehensively analyzed the genetic alterations in AML patients in comparison with the WHO classification. The study population included 115 newly diagnosed AML patients consisting of 25 recurrent genetic abnormalities, 25 multilineage dysplasia, 7 therapy-related and 56 not otherwise categorized WHO subcategories. Bone marrow samples were obtained from the patients after obtaining informed consent for banking and molecular analyses. Mutations in FLT3, cKIT, NPM1, N-RAS, p53, C/EBPa, AML1 and AKT1 genes were analyzed as previously described. In consistent with previous reports, FLT3 (20.9%), NPM1 (14.8%) and C/EBPa (13.0%) mutations were frequently observed, while no AKT1 mutation was found. Furthermore, NPM1 mutation was not found in AML with recurrent genetic abnormalities and C/EBPa mutation was not found in AML with recurrent genetic abnormalities or therapy related. Nine cases have double mutations of FLT3 and NPM1 genes, and 3 have FLT3 and C/EBPa mutations. Of note is that 15 of 25 (60%) AML with multilineage dysplasia cases have at least one mutation in p53, NPM1, C/EBPa, FLT3, N-RAS and AML1 genes and that p53 mutation was selectively found in the cases with complex karyotype. However, 4 AML with multilineage dysplasia cases with normal karyotype did not have any mutations in the analyzed genes. Comprehensive genetic analysis clarifies the detailed molecular base of AML and could make the subdivision of the WHO classification by combining the analysis for clinical impacts. Especially, mutation status in p53, NPM1 and C/EBPa genes seems to be useful for the subdivision of the AML with multilineage dysplasia, which is the most heterogeneous subcategory in the WHO classification.
One-Mutation Model Can Explain Age Incidence in AML Carrying Nucleophosmin (NPM1) Mutations.
Authors: Liso Arcangelo , Castiglione Filippo , Cappuccio Antonio , Stracci Fabrizio , Thiede Christian , Ehninger Gerhard , Schnittger Susanne , Haferlach Torsten , Valk Peter , Lowenberg Bob , Martelli Massimo F. , Falini Brunangelo 
Published: October 2019

Abstract
Acute myeloid leukemia (AML) carrying nucleophosmin (NPM1) mutations and cytoplasmic NPM (NPMc+ AML) accounts for about one-third of all AML patients, and exhibits distinctive biological and clinical features. The role of NPM1 mutations in leukemogenesis remains elusive. Mathematical models have been developed that, starting from cancer incidence data, allow to infer the somatic mutation rate, or the number of genetic events required to cause cancer. We collected data on age at diagnosis of AML patients from four centers in three different countries, and calculated age-specific rates of NPMc+ AML. A total of 4,155 AML patients were investigated. NPM1 mutations these were detected in 1288. Patients carrying NPM1 mutations with age below 20 years and above 59 years were excluded from the study because of the low number of younger cases and because older patients are not always referred to major institutions for diagnosis and treatment. To investigate NPMc+ AML we adapted one-mutation model published by Michor et al (PNAS, 2006; 103: 14931). The mathematical model consider a population of N (hemopoietic stem) cells that at beginning are wild-type. These cells proliferate according to the Moran process. The growth follows a logistic law with a saturation term. Our process follows the “classical” Moran process up to the appearance of a successful mutant. After that, the clone expands to a limiting population size. This is done to account for the dramatic expansion of the initial compartment peculiar of AML. Finally the rate of AML detection is proportional to the number of mutated cells. Experimental incidence curves of AML in Germany (Ge), Netherlands (Nl), and Italy (It) plotted simultaneously with predicted one-mutation model estimates are shown in Fig. 1. Linear regression of curves representing age-specific rate of diagnoses per year showed similar slopes (about 4 on a double-log scale) in different countries. The one-event model reproduces well the “exponential phenotype” of NPMc+ AML. In conclusion the model is in accordance with the hypothesis that NPM1 mutations by themselves are sufficient to cause NPMc+ AML. Alternatively, it is still possible that NPM1 mutations might cooperate with other molecular alterations to cause AML. In particular, since NPM1 mutations cause haploinsufficiency of wild-type NPM in leukemic cells and in knock-out mice NPM haploinsufficiency results in a MDS-like syndrome and given that the NPM1 mutant has oncogenic properties, these alterations could act in concert to cause AML. Indeed, the effect of these two alterations occurring simultaneously could be seen as a single genetic event.
Figure Figure
CD52 Is Expressed in Childhood Acute Myeloid Leukemia and May Be a Target for Alemtuzumab.
Authors: Wegmann Matthew K. , Berger James , Bostrom Bruce , Messinger Yoav H. 
Published: October 2019

Abstract
Event free survival in children with Acute Myeloid Leukemia (AML) remains low at approximately 50%, and more effective therapy is urgently needed. Alemtuzumab is an anti-CD52 humanized antibody with activity in Chronic Lymphocytic Leukemia. In adults with AML, CD52 was expressed in 36% of patients. Alemtuzumab treatment in relapsed adult AML patients resulted in complete response without platelet recovery (CRp) in 2/9 (22%), reduction of marrow blasts in 1/9 (11%) and reduction of peripheral blasts in 5/9 (56%) (Cancer, 2006;106:2645–51). The expression of CD52 has not been reported in childhood AML. AML (excluding M3) was diagnosed in 48 children at our institution from February 2002 to February 2007. The flow cytometric expression of CD52 antigens was studied in 41 pediatric patients at diagnosis: 20 girls and 21 boys and median age 5.1 years (range 0–18). CD52 expression ≥ 20% of leukemic blasts was considered positive. Of the 41 AML patients, 19 (46%) were positive and 22 (54%) were negative for CD52. In the CD52 positive patients the median expression was 72% (range 22%–99%), and intensity was moderate to dim. Expression by cytogenetic risk groups is demonstrated in Table 1:
Cytogenetic Risk Group Low Risk: t(8;21) or Inv(16)/t(16;16) Intermediate Risk High Risk: −7 or -5/5q- Down Syndrome CD52 positive 7 9 2 1 CD52 negative 2 13 3 4
More low-risk patients were CD52 positive than negative, but the reverse was true for patients with Down syndrome. Age, gender, FAB subtype or presenting white blood cell count did not correlate with CD52 expression. Event free survival and overall survival were similar in CD52 positive and negative patients. In summary, CD52 is expressed in almost half of children with AML. The activity of single agent Alemtuzumab in adults with AML suggests that this agent should be evaluated to treat CD52-positive pediatric AML patients in combination with chemotherapy.
Clinicopathological Analysis of 32 Cases of Extra-Medullary Myeloid Tumour.
Authors: Todd Tony , Besser Martin W. , Craig Jenny I. , Marcus Robert E. 
Published: October 2019

Abstract
We performed a retrospective analysis of 32 cases of extramedullary myeloid tumour in patients aged 11 weeks – 85 years (median 26 years), identified from the records of the Addenbrooke’s Hospital Department of Pathology over a 10 year period from 1st January 1997 to 15th January 2007. Records were reviewed for diagnosis, immunohistochemical stains, demographics, clinical and radiological features, treatment and outcome. 9 patients (28%) had a pre-existing haematological disorder, 6 (19%) presented with simultaneous EMMT and leukaemia, and 17 cases (53%) with de novo isolated EMMT. The most commonly positive immunohistochemical stains were CD43 (100%), CD45 (95%), CD68-PGM1 (91%), MPO (83%), CD 15 (78%) and CAE (73%). None of the 26 cases tested was positive for CD3, cytokeratin was negative in all tested patients, two cases were positive for CD79a, 9 of 9 cases were strongly positive for MIB1, 6 of 6 were positive for bcl-2, and vimentin positive in 3 of 3 cases. Misdiagnosis occurred in 10 out of the 17(59%) isolated de novo presentations. These were thought to be lymphoma (6/10), sarcoma (1/10), plasmacytoma (1/10), rhabdomyosarcoma (1/10) and fibromyomatosis (1/10). All the bcl-2 positive cases were misdiagnosed as non-Hodgkin’s lymphoma, even in the absence of specific B- or T-cell markers, and 1 vimentin positive case as sarcoma. No misdiagnosed case was initially tested for chloroacetate esterase or myeloperoxidase, in 9 subsequent testing showed one or both to be positive. 9 of 32 cases were (28%) long term survivors with a median follow up 1610 days, 7 adults and 2 children. Two received local therapy only with excision and radiotherapy, all others received intensive AML chemotherapy. There was only 1 long term survivor of the 6 patients initially given non-AML chemotherapy as a result of misdiagnosis. In that patient the diagnosis was revised within 14 days. All other misdiagnosed patients treated with non AML chemotherapy progressed to AML and were unsalvageable. Isolated EMMT may give rise to significant diagnostic difficulty. These tumours are usually positive for CD45, MPO and CAE but unless these are tested for, isolated expression of vimentin and bcl-2 may be misleading. In our series outcome was adversely affected by diagnostic delay, initial non-AML therapy, lymphadenopathy and tumour bulk (>10cm) at diagnosis. In correctly diagnosed patients AML chemotherapy alone may be sufficient to achieve long-term disease free survival in contrast to other recently published studies.
Flt3 Mutations in Proximity to an Ubiquitin Dependent Endocytosis Motif Suspend Its Hdm2 Modulation.
Authors: Wergeland Line , Oveland Eystein , Sjoholt Gry , Bedringaas Siv Lise , Hovland Randi T. , Bruserud Oystein , Gjertsen Bjorn T. 
Published: October 2019

Abstract
Acute myeloid leukemia (AML) frequently features mutations in the receptor tyrosine kinase Flt3 and elevated expression of the oncogenic E3 ubiquitin ligase Hdm2. Additional to the p53 inhibitory effect of Hdm2, Hdm2 appears involved in endocytosis of cell surface receptors. In this study we explore the possibility of Flt3 modulation by Hdm2 in primary AML cells and cell lines (NB4 and MV4–11) with wild type Flt3 (Flt3-wt) or mutated Flt3 (Flt3-ITD). Flt3 ligand (FL), small molecular inhibitors and small interfering RNA (siRNA) were used to elucidate the relation between Flt3 and Hdm2 on protein level, mRNA expression and modulation of apoptosis. The basal level of Flt3 is higher in AML patients with Flt3-ITD than in patients with Flt3-wt. Flt3-ITD affects a ubiquitin endocytosis motif that in some patients are duplicated, possibly resulting in enhanced receptor cycling. Down-regulation of Flt3-wt by FL, small interfering RNA or PKC412 resulted in elevated level of Hdm2. Similarly, Hdm2 attenuation resulted in increased Flt3 protein expression. Flt3-ITD responded less to Flt3 down-regulation, and was only weakly responding to Hdm2 modulation. We demonstrate that modulation of Flt3 or Hdm2 results in reciprocal regulation, and that Flt3 with internal tandem duplications may suspend its Hdm2 modulation. Together, Flt3-ITD results in dysregulated receptor turnover and elevated Hdm2 thus interconnecting the two pathways of Flt3 and p53, both related to chemoresistance in AML.