scholarly journals Gene Expression Profiling in the Classification of Acute Leukemia Brazilian Patients

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5315-5315
Author(s):  
Carolina Pereira de Souza Melo ◽  
Catharina Brant Campos ◽  
Alvaro Pimenta Dutra ◽  
Angelo Atalla ◽  
Mara Albonei Dudeque Pianovski ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Leukemia ◽  
De Novo ◽  
Conflicts Of Interest ◽  
Bioinformatic Analysis ◽  
Gene Signature ◽  
World Health ◽  
Prediction Algorithm ◽  
Lymphoid Leukemia ◽  
Number Of Patients

Abstract In the past few decades, genetic data has become increasingly important for acute leukemia diagnosis and patients stratification. Indeed, the present World Health Organization (WHO) leukemia classification system is largely based upon genetically defined subgroups. Gene expression profile (GEP) may correctly predict most genetic leukemia subtypes, but so far no GEP report has evaluate patients from Latin America. In the present study, we used gene expression microarray data to build an acute leukemia classifier. Bone marrow samples were collected from 231 individuals at diagnosis, 110 presented de novo acute myeloid leukemia (AML), 97 had de novo acute lymphoid leukemia (ALL) and the remaining 24 were controls who had other conditions including chronic leukemias or non-hematological diseases. GEP was evaluated based on mRNA expression signatures obtained with the Sure Print G3 Human GE (60k) system (Agilent Technologies). k-nearest neighbors prediction algorithm was applied and the top 60 informative genes were selected for each of the most prevalent genetic subtypes (T-ALL, B-ALL BCR-ABL, B-ALL ETV6-RUNX1, B-ALL TCF3-PBX1, AML PML-RARa, AML RUNX1-RUNX1T1, AML FLT3-ITD, AML NPM1mut). The less prevalent groups such as MLL rearranged and CBFB-MYH11 were not included in the classifier because of the low number of patients carrying these aberrations in our cohort. Performance of each prediction model was assessed by leave-one-out crossvalidation through the GenePattern platform (Broad Institute). The average classifier accuracy was 94.75%. Higher accuracy and precision were achieved for T-ALL (99%/96%) and AML PML-RARa (97%/97%). However, for ALL BCR-ABL, AML FLT3-DIT and AML NPM1mut the gene signature had low precision rates (74%, 66% and 80%, respectively). The data presented here confirm that a single platform of gene expression followed by bioinformatic analysis can correctly classify genetic subgroups, but a refinement of the classifier developed is needed in order to improve the detection of heterogeneous entities such as BCR-ABL or FLT3-ITD carriers. Disclosures No relevant conflicts of interest to declare.

Characteristics of De Novo Acute Leukemia Patients with Glycosylphosphatidylinositol (GPI) Protein-Negative Population of Leukemic Cells.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4462-4462
Author(s):  
Hideyoshi Noji ◽  
Tsutomu Shichishima ◽  
Masatoshi Okamoto ◽  
Kazuhiko Ikeda ◽  
Akiko Nakamura ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Leukemia ◽  
De Novo ◽  
Bone Marrow Failure ◽  
Flow Cytometric Analysis ◽  
Leukemic Cells ◽  
Remission Induction ◽  
Color Flow ◽  
Flow Cytometric ◽  
Number Of Patients

Abstract Paroxysmal nocturnal hemoglobinuria (PNH) is considered to be an acquired stem cell disorder affecting all hematopoietic lineages, which lack GPI-anchored membrane proteins, such as CD59, because of abnormalities in the phosphatidylinositol glycan-class A (PIG-A) gene. Also, PNH is one disorder of bone marrow failure syndromes, including aplastic anemia and myelodysplastic syndrome, which are considered as pre-leukemic states. In this study, to know some characteristics of patients with de novo acute leukemia, we investigated expression of CD59 in leukemic cells from 25 patients (female: male=8: 17; mean age ± standard deviation, 57.8 ± 19.5 years) with de novo acute leukemia by single-color flow cytometric analysis. In addition, the PIG-A gene from CD59− leukemic cells sorted by FACS Vantage in 3 patients with acute leukemia was examined by sequence analysis. All the patients had no past history of PNH. Based on the French-American-British criteria, the diagnosis and subtypes of acute leukemia were determined. The number of patients with subtypes M1, M2, M3, M4, M5, and M7 was 1, 14, 2, 4, 2, and 2, respectively. Two of the patients were classified into acute myeloid leukemia with trilineage myelodysplasia from morphological findings in bone marrow. Chromosomal analyses presented abnormal karyotypes in 14 of 25 patients. Flow cytometric analyses showed that leukemic cells from 16 of 25 patients (64%) had negative populations of CD59 expression and the proportion of the populations was 63.3 ± 25.7%, suggesting the possibility that CD59− leukemic cells from patients with de novo acute leukemia might be derived from PNH clones. In fact, the PIG-A gene analyses showed that monoclonal or oligoclonal PIG-A mutations in coding region were found in leukemic cells from 3 patients with CD59− leukemic cells and all of the clones with the PIG-A mutations were minor. Then, various clinical parameters, including rate of complete remission for remission-induction chemotherapy, peripheral blood, bone marrow blood, and laboratory findings, and results of chromosomal analyses were statistically compared between 2 groups of patients with (n=16) and without (n=9) CD59− leukemic cells. The reticulocyte counts (10.5 ± 13.0 x 104/μl) and proportions of bone marrow erythroblasts (17.5 ± 13.9%) in patients with only CD59+ leukemic cells were significantly higher than those (2.5 ± 1.7 x 104/μl, p<0.05; and 5.6 ± 6.2%, p<0.01, respectively) in patients with CD59− leukemic cells. The proportions of bone marrow blasts (69.3 ± 21.1%) in patients with CD59− leukemic cells were significantly higher than those (45.5 ± 19.3%, p<0.02) in patients with only CD59+ leukemic cells. In conclusion, our findings indicate that leukemic cells derived from PNH clones may be common in de novo acute leukemia patients, suggesting that bone marrow failure may have already occurred in localized bone marrow even in de novo acute leukemia.

Microarray Classification of Myelodysplastic Syndrome (MDS) Identifies Subgroups with Distinct Clinical Outcomes.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2426-2426
Author(s):  
Ken I. Mills ◽  
Alex Kohlmann ◽  
Mickey Williams ◽  
Wei-Min Liu ◽  
Rachel Li ◽  
...  
Keyword(s):  
Gene Expression ◽  
De Novo ◽  
Cell Signalling ◽  
Bioinformatic Analysis ◽  
Initial Study ◽  
Outcome Data ◽  
Kaplan Meier ◽  
Significant Difference ◽  
Gene Expression Signatures ◽  
Microarray Classification

Abstract The MILE (Microarray Innovations in LEukemia) study has previously shown that gene expression signatures associated with initial leukaemia classifier (LCver7) give an overall cross-validation accuracy of >95% for distinct sub-classes of pediatric and adult leukemias. However, only 50% of the 174 MDS samples in the whole-genome microarray analysis (Stage 1) of the MILE study were correctly identified; the remainder showed AML-like or non-leukemia-like gene profiles. An external morphological review (DB & HL) according to FAB and WHO criteria, of the 174 slides was performed independently (blind) which resulted in 6 samples being reclassified as AML and 4 non-leukemia cases excluded from the study. A recently improved, hierarchical based algorithm correctly identified 100% of the confirmed MDS cases. In this study, using LCver7, the confirmed 164 samples had 50% MDS classifications (Class 17), 23.8% non-leukemia classifications (Class 18), and 22.6% AML classifications (Classes 13 or 14) with the remaining 3.7% having a classification tie between 2 or 3 Classes (due to low confidence). No 5q- syndrome patients had an AML call, whilst 68.3% of RAEB2 patients had an AML classification and none were Class 18. Similarly, 95.6% of Low IPSS patients were classified as Class 17 or 18, whilst all patients (n=5) with High IPSS had an AML call. The classification was independent of blast cells: 10.2% of Class 18 calls had >5% blasts; 28.2% of AML-like cases had <5% blasts. Outcome data (132 MDS patients) was correlated with Class: significant difference (p<0.028, (Kaplan-Meier)) was seen in overall survival; with p <0.004 if AML (Classes 13 & 14) was compared to “non AML” (Classes 17 & 18). Statistically significant differences were seen for time to transformation to AML between the classes (p<0.0001) and between AML and “non AML” (p<0.00007, Kaplan-Meier)) with a probability of transformation of 44% at 18 months for the AML group compared to <8% for the “non-AML” group. A further linear classifier has been used to discriminate patients who transform to AML within 18 months (poor prognosis) with patients with no transformation after >60 months (good prognostic group). Bioinformatic analysis of molecular mapped functions and canonical pathways showed that cell signalling processes were over-represented when comparing de novo AML (n=204) with MDS, from the MILE study, whilst signal transduction pathways were deregulated when comparing non-leukemia samples (n=71) with MDS. Similar pathways and functions were also deregulated when comparing the correctly classified MDS with Class 17 call against MDS with Class 18 call and MDS with AML Classes 13 or 14 calls. In conclusion, the use of microarrays within the initial study, solely intended for diagnostic purposes, has now evolved towards a position in which novel prognostic value may be gained from distinct gene expression signatures. This has also resulted in a better molecular understanding of the progression from non-leukemia, through MDS into full blown AML.

A Meta-Analysis of CAG (cytarabine, aclarubicin, G-CSF) Regimen for the Treatment of 1045 Patients with Leukemia in China and Japan,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3638-3638
Author(s):  
Guoqing Wei ◽  
Wanmao Ni ◽  
Dicky Chiao ◽  
He Huang ◽  
Zhen Cai ◽  
...  
Keyword(s):  
Acute Leukemia ◽  
Fixed Effects ◽  
De Novo ◽  
Conflicts Of Interest ◽  
Meta Analysis ◽  
Early Death ◽  
Newly Diagnosed ◽  
Significant Difference ◽  
China And Japan ◽  
Better Than

Abstract Abstract 3638 Background: CAG regimen (cytarabine, aclarubicin, G-CSF) has been commonly used in China and Japan for the treatment of AML and MDS. This study is to summarize the data and to analyze the efficacy as well as the toxic effects of CAG regimen in acute leukemia (AL) and MDS pts. Methods: The databases of PubMed, Wanfang Data, as well as American Society of Hematology (ASH) annual meeting abstracts were searched for articles published in English, Chinese and Japanese languages between January 1995 and December 2010. Eligible studies were relevant clinical trials on AL and MDS pts treated with CAG regimen. Complete remission (CR) rates and odds ratio (OR) were compared through a meta-analysis using a random-effects or fixed-effects model. Results: 37 trials with a total of 1045 AL and MDS pts were included for analysis. Among the 1045 pts treated with CAG, 819 pts were AML, 215 pts were de novo MDS or transformed AML (MDS/tAML), 6 pts were ALL, and 5 pts were biphenotypic acute leukemia (BAL). The AML CR rate of CAG from 29 studies was 58.0% (95% CI, 53.1%-62.7%). The MDS/t-AML CR rate from 12 studies was 45.7% (95% CI, 39.0%-52.4%). The AML CR rate was significantly better than that of MDS /tAML (Q=8.072, p<0.01). Among 819 AML pts, 327 pts were newly diagnosed, 370 pts were relapsed/refractory (R/R) AML. The AML status was not specified in the rest 122 pts. Interestingly, no significant difference in CR rates was noted between the newly diagnosed (57.0%, 95% CI 51.5%-62.3%) and R/R AML pts (60.1%, 95% CI 50.5%-68.9%) (Q=0.312, p>0.05). The CR rate for the 367 elderly AML pts was 52% (95% CI 51.5%-62.3%). The CR rate was also significantly higher in pts with favorable (64.5%, 95% CI 38.8%-83.9%) and intermediate (69.6%, 95% CI 60.4%-77.5%) cytogenetics than those with unfavorable one (29.5%, 95% CI 19.7%-41.8%) (p<0.05). There were 7 trials that compared the CR rates of CAG regimen with those of other induction regimens in AML pts. Surprisingly, the CR rate of CAG was significantly higher than those of other induction regimens (OR 2.425, 95% CI, 1.515–3.880). CAG regimens were well tolerated with cardiotoxicity in 0.42% cases (4/954) and early death occurred in 4.40% cases (44/1000). Conclusions: CAG regimen induced significantly higher CR rates in AML than in MDS pts. The CR rates of CAG regimen was significantly better than those of other induction regimens in AML pts. This regimen was well tolerated with low cardiotoxicity and early death rate. Disclosures: No relevant conflicts of interest to declare.

Disease-Relevant Expression Of TRAF6 In Mouse HSC Results In An MDS-Like Disease

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 101-101
Author(s):  
Jing Fang ◽  
Xiaona Liu ◽  
Brenden Barker ◽  
Lyndsey Bolanos ◽  
Yue Wei ◽  
...  
Keyword(s):  
Gene Expression ◽  
Conflicts Of Interest ◽  
Early Stage ◽  
Bone Marrow Failure ◽  
Gene Signature ◽  
Sublethal Dose ◽  
Hematopoietic Tissue ◽  
Hematopoietic Stem ◽  
Disease Evolution ◽  
Cd34 Cells

Abstract Overexpression of immune-related genes is widely reported in Myelodysplastic Syndrome (MDS), and chronic immune stimulation increases the risk for developing MDS. We find that TNF receptor associated factor 6 (TRAF6), an innate immune protein, is overexpressed approximately 2-fold in CD34+ cells from 40% of MDS patients, and may explain immune pathway activation in the MDS-initiating hematopoietic stem/progenitor cell (HSPC). In support of these observations and our hypothesis that TRAF6 is important in the pathophysiology of MDS, a gene expression analysis revealed that TRAF6 controls an MDS gene signature in human cells. We, and others, have previously shown that retroviral overexpression of TRAF6 in mouse HSPC results in MDS and Acute Myeloid Leukemia (AML). However, interpretations of these findings are hampered by supra-physiological levels of TRAF6 (>10-fold overexpression) and the stress associated with HSPC transduction/transplantation. To investigate the consequences of TRAF6 overexpression to MDS, we generated a transgenic mouse model overexpressing TRAF6 from a hematopoietic-specific Vav promoter. Expression of TRAF6 in HSPC was approximately 2-fold higher as compared to endogenous TRAF6 and in line with MDS patient CD34+ cells. By 15 months of age, half of Vav-TRAF6 mice succumbed to a hematologic disease resembling MDS associated with bone marrow failure (BMF). In contrast to the retroviral overexpression approach, Vav-TRAF6 mice did not develop AML. Examination of sick mice revealed stage-specific disease evolution. Initially, all Vav-TRAF6 mice exhibit an inversion of myeloid/lymphoid proportions. For Vav-TRAF6 mice that develop a fatal disease, they present with a hypocellular marrow, dysplasic myeloid cells, and neutropenia. A subset of mice also display anemia with nucleated red blood cells, poikilocytosis, and extramedullular erythropoiesis. In support of a BMF phenotype, HSPC from Vav-TRAF6 mice form fewer colonies in methylcellulose. To investigate the consequences of an acute exposure to pathogen, early-stage Vav-TRAF6 mice were treated with a single sublethal dose of lipopolysaccharide (LPS). Unlike wild-type (WT) mice, Vav-TRAF6 mice developed a rapid and reversible anemia, suggesting environmental factors can influence the severity of the disease. To gain insight into the mechanism contributing to BMF, gene expression profiling was performed in WT and Vav-TRAF6 HSPC. One of the enriched pathways consisted of AKT activation and FOXO downregulation. Consistent with the microarray analysis, AKT is constitutively phosphorylated at Thr308 in hematopoietic tissue from Vav-TRAF6 mice. SOD2, a transcriptional target of FoxO3a that is suppressed by activated AKT, is decreased in Vav-TRAF6 HSPC. Given that AKT/FOXO regulate reactive oxygen species (ROS) in cells, we investigated ROS levels in HPSC from Vav-TRAF6 and WT mice. Intracellular ROS is significantly elevated in BM cells from Vav-TRAF6 mice, and restored to normal levels when AKT was inhibited. In conclusion, we propose the potential role of TRAF6 in the development of MDS-associated BMF, partly due to constitutive activation of AKT and subsequent ROS elevation in HSPC cells. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Trisomy 13: a new recurring chromosome abnormality in acute leukemia

Blood ◽  
1990 ◽  
Vol 76 (8) ◽  
pp. 1614-1621 ◽  
Author(s):  
H Dohner ◽  
DC Arthur ◽  
ED Ball ◽  
RE Sobol ◽  
FR Davey ◽  
...  
Keyword(s):  
Acute Leukemia ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Chromosome Abnormality ◽  
Cell Receptor ◽  
Trisomy 13 ◽  
Lymphoid Leukemia ◽  
High Incidence ◽  
T Cell Receptor Beta ◽  
Hematopoietic Precursor

Abstract A new recurring chromosome abnormality was identified in 8 of 621 consecutive successfully karyotyped adults with de novo acute leukemia. These eight patients had trisomy 13 as the sole cytogenetic abnormality. On central morphologic review, five cases were classified as subtypes of acute myeloid leukemia, one as acute mixed lymphoid and myeloid leukemia, one as acute lymphoid leukemia, and one as acute undifferentiated leukemia. Blasts of all eight cases expressed one or more myeloid differentiation antigens. Three also expressed T-lineage- associated antigens; however, none of these had rearrangement of the T- cell receptor beta, gamma, or delta genes. Four of six cases tested were TdT positive. All eight patients with trisomy 13 were treated with intensive induction chemotherapy; only three entered a short-lived complete remission. Survival of patients with trisomy 13 ranged from 0.5 to 14.7 months, and was significantly shorter than that of the remaining patients (median 9.5 v 16.2 months, P = .007). We conclude that trisomy 13 is a rare, recurring clonal chromosome abnormality in acute leukemia associated with a poor prognosis. Malignant transformation of an immature hematopoietic precursor cell is suggested by the expression of antigens characteristic of both the myeloid and lymphoid lineage, the high incidence of TdT positivity, and the morphologic heterogeneity in these leukemias.

Poor Outcome in Secondary Acute Myeloid Leukemia (AML): A First Report From the Population-Based Swedish Acute Leukemia Registry

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 130-130 ◽  
Author(s):  
Soren Lehmann ◽  
Vladimir Lazarevic ◽  
Ann-Sofi Hörstedt ◽  
Erik Hulegårdh ◽  
Christer Nilsson ◽  
...  
Keyword(s):  
Acute Leukemia ◽  
De Novo ◽  
Conflicts Of Interest ◽  
Performance Status ◽  
Population Based ◽  
Induction Treatment ◽  
Secondary Aml ◽  
Male Predominance ◽  
Hematological Disorder ◽  
De Novo Aml

Abstract Abstract 130 Secondary AML comprises AML patients with an antecedent hematological disorder (AHD) or previous exposure to chemotherapy and/or radiation (therapy-related AML; tAML). Population-based data on this patient group are scarce. Here, we report for the first time, data on secondary AML from the Swedish Acute Leukemia Registry covering 98% of all AML cases diagnosed in Sweden between 1997 and 2006. In total, 3372 AML patients were registered during this period. Of these, 949 (28%) had secondary AML; 655 (19%) had a history of AHD and 294 (8.7%) had tAML. The proportion of secondary AML increased from 8% in patients below the age of 40 years to 36% in patients between 70–79 years. Of patients with AHD, 423 (65%) had previously been diagnosed with myelodysplastic syndrome (MDS) and 227 (35%) with various types of myeloproliferative disorders (MPN). AML with AHD showed male predominance (57%), whereas tAML showed female predominance (64%). This distribution was significantly different (p<0.001) compared to de novo AML with an equal gender distribution. Median and mean ages for patients with AML with antecedent hematological disorder were 73 and 71 years, which differed significantly from de novo AML with 70 and 66 years, respectively (p<10−11). For tAML, median and mean ages were 71 and 67 years, respectively, not significantly different from de novo AML. Patients with secondary AML had slightly worse WHO/ECOG performance status (WHO PS) with lower incidence of WHO PS 0 (10%: 14%: 18% for AML with AHD:tAML:de novo AML) and a higher incidence of WHO PS 3–4 (27%: 24%: 20%). The proportion of patients with PS 1 and PS2 was similar for secondary AML and de novo AML. Intensive induction treatment was given to 45% of all patients with AHD, to 57% of patients with tAML compared to 68% for patients with de novo AML. In patients below the age of 65, the proportion of intensively treated patients was 76, 85 and 98%, respectively. CR rates for in patients including all ages were 40% for AML with AHD, 54% for tAML and 72 % for de novo AML (p-values<0.0001 for all calculations). CR rates were lower in all cytogenetic risk groups in both AML with AHD and tAML compared to de novo AML (Low risk NA: 70%: 91%; intermediate risk 53%: 56%: 89%; high risk 30%: 43%: 76%). CR rates were lower for both secondary leukemia types within all WHO PS groups, despite similar early death rates in secondary and de novo AML. Median survival for all patients regardless of age or type of treatment was 4 mo, 4 mo and 9 mo respectively for patients with AML with AHD, tAML and de novo AML, respectively. For all patients receiving intensive induction treatment, corresponding figures were 7 mo, 9 mo and 17 mo, and for patients below 65 years of age 7 mo, 9 mo and 38 mo. We conclude that secondary AML is less common in younger patients and that the proportion increases to a third of patients above 70. Patients with AHD and tAML less often receive intensive induction treatment than those with de novo AML and treatment responses are poor regardless of cytogenetic risk group or performance status also in intensively treated patients. Disclosures: No relevant conflicts of interest to declare.

Glycosylphosphatidylinositol (GPI) Protein-Negative Population of Leukemic Cells in Patients with De Novo Acute Leukemia.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3264-3264
Author(s):  
Hideyoshi Noji ◽  
Tsutomu Shichishima ◽  
Masatoshi Okamoto ◽  
Kazuhiko Ikeda ◽  
Akiko Nakamura ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Leukemia ◽  
De Novo ◽  
Past History ◽  
Bone Marrow Failure ◽  
Flow Cytometric Analysis ◽  
Leukemic Cells ◽  
Color Flow ◽  
Flow Cytometric ◽  
Number Of Patients

Abstract Paroxysmal nocturnal hemoglobinuria (PNH) is considered to be an acquired stem cell disorder affecting all hematopoietic lineages, which lack GPI-anchored membrane proteins, such as CD59, because of abnormalities in the phosphatidylinositol glycan-class A (PIG-A) gene. Also, PNH is one disorder of the bone marrow failure syndromes, including aplastic anemia and myelodysplastic syndrome, which are considered as pre-leukemic states. In this study, to know some condition of pre-leukemic states in patients with de novo acute leukemia, we investigated the expression of CD59 in leukemic cells from 25 patients (female: male=8: 17; mean age, 57.8 ± 19.5 years) with de novo acute leukemia by single-color flow cytometric analysis. In addition, the PIG-A gene from CD59− leukemic cells, sorted by FACS Vantage, in 10 patients with acute leukemia was examined by sequence analysis. All the patients had no past history of PNH. Based on the French-American-British criteria, the diagnosis and subtypes of acute leukemia were determined. The number of patients with subtypes M1, M2, M3, M4, M5, and M7 was 1, 14, 2, 4, 2, and 2, respectively. Two of the patients were classified into acute myeloid leukemia with trilineage myelodysplasia from morphological findings in bone marrow. Chromosomal analyses presented abnormal karyotypes in 14 of 25 patients. Flow cytometric analyses showed that leukemic cells from 16 of 25 patients (64%) had negative populations of CD59 expression and the mean proportion of the populations was 63.3 ± 25.7%, suggesting the possibility that CD59− leukemic cells from patients with de novo acute leukemia might be derived from PNH clones. In fact, the PIG-A gene analyses showed that single (n=4) or multiple (n=6) PIG-A mutations in coding region were found in leukemic cells from 10 patients with CD59− leukemic cells and all of the clones with the PIG-A mutations were statistically minor. Then, various clinacal parameters, including peripheral blood, bone marrow blood, and laboratory findings and the results of chromosomal analyses were statistically compared between 2 groups of patients with (n=16) and without CD59− leukemic cells (n=9). The reticulocyte counts (mean ± standard deviation; 10.5 ± 13.0 x 104/μl) and proportions of bone marrow erythroblast (17.5 ± 13.9%) in patients with only CD59+ leukemic cells were significantly higher than those in patients with CD59− leukemic cells (2.5 ± 1.7 x 10 4/μl; p&lt;0.05 and 5.6 ± 6.2%; p&lt;0.01, respectively). The proportions of bone marrow blasts (69.3 ± 21.1%) in patients with CD59− leukemic cells were significantly higher than that those in patients with only CD59+ leukemic cells (45.5 ± 19.3%; p&lt;0.02). In conclusion, our findings indicate that leukemic cells derived from PNH clones may be fairly common in de novo acute leukemia patients, suggesting that bone marrow failure as pre-leukemic states may have already occurred in localized bone marrow even in de novo acute leukemia.

Indolent Mastocytosis in 159 Adults: Smoldering but Not Bone Marrow Only Variant Is Prognostically Significant.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2906-2906
Author(s):  
Animesh D. Pardanani ◽  
Ken-Hong Lim ◽  
Terra L Lasho ◽  
Christy Finke ◽  
Rebecca McClure ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Leukemia ◽  
Clinical Characteristics ◽  
Who Classification ◽  
Conflicts Of Interest ◽  
World Health ◽  
Serum Tryptase ◽  
Cytogenetic Abnormalities ◽  
Tryptase Level ◽  
Health Organization

Abstract Abstract 2906 Poster Board II-882 Background: The World Health Organization (WHO) classification system recognizes indolent SM (ISM) as an entity characterized by low systemic mast cell (MC) burden but frequent skin involvement. The WHO system also recognizes 2 provisional ISM sub-variants: smoldering SM (SSM) and bone marrow (BM) mastocytosis (BMM). The two are respectively characterized by increased systemic MC burden (presence of ≥ 2 ‘B-findings') and BM MC infiltration in the absence of skin or multiorgan visceral lesions. The prognostic relevance of this sub-classification remains unclear. Methods: The study population was drawn from a larger cohort of 342 adult SM patients (Blood. 2009 Jun 4;113(23):5727). Clinical data and BM histology were reviewed, and the diagnosis of ISM and its subclassification confirmed per the 2008 WHO proposal. The primary objectives of the study were to: (i) describe the clinical characteristics of a large cohort of ISM patients, within the context of the WHO classification; (ii) evaluate the prevalence of molecular and cytogenetic abnormalities; (iii) evaluate whether ISM subclassification is prognostically relevant on the basis of survival and risk of transformation to acute leukemia or aggressive SM (ASM). Results: (i) Clinical characteristics: 159 ISM patients were evaluated (69 males; median age 49 years, range 19-84); 22 (14%) had SSM, 36 (23%) BMM, and 101 (63%) ‘ISM-other' (ISMo). By definition, ‘B-findings' were absent in BMM patients. ‘B-findings' in SSM (and ISMo) patients was as follows: hepatosplenomegaly and/or lymphadenopathy 91% (21%), BM MC >30% or serum tryptase level >200ng/mL 68% (8%), and hypercellular BM or dysmyelopoiesis without cytopenias 50% (2%). SSM patients were older (p<0.01) and more frequently displayed constitutional symptoms (p<0.01), and anemia (p<0.01). MC mediator-release symptoms (p=0.01), including anaphylaxis (p<0.01), were more frequent in BMM. The following MC-mediators were studied: serum tryptase (57%), beta prostaglandin F2alpha (45%), urine methylhistamine (32%), and urine histamine (21%) – significant differences were noted amongst the ISM subgroups with the following relationship: SSM>ISMo>BMM (p<0.01). (ii) Molecular and cytogenetic abnormalities: Complete karyotype information was available for 55 patients; only 1 patient (with ISMo) had an abnormal karyotype. Fifty nine patients were screened for KITD816V and JAK2V617F; JAK2V617F was universally absent, and distribution of KITD816V was not significantly different amongst the ISM subgroups: SSM (100%), BMM (92%), and ISMo (69%). (iii) Survival and risk of disease transformation: At a median follow of 27 months (range <1-417), 26 deaths were recorded (ISMo 14, SSM 10, and BMM 2), and the combined median survival was 198 months: ISMo 301 months, SSM 120 months, and BMM (not reached) (p<0.01; Figure). Transformation to acute leukemia and ASM was seen in 1 patient (SSM) and 3 patients (2 SSM and 1 ISMo), respectively. Conclusions: Among WHO-defined ISM patients, SSM is associated with significantly shorter survival whereas BMM and ISMo are prognostically similar. If these observations are confirmed by others, consideration may be given to classifying SSM as a distinct subcategory of SM, instead of a sub-variant of ISM as it currently stands. Disclosures: No relevant conflicts of interest to declare.

Long Noncoding RNAs in Erythropoiesis and Megakaryopoiesis.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2331-2331
Author(s):  
Vikram R Paralkar ◽  
Tejaswini Mishra ◽  
Jing Luan ◽  
Yu Yao ◽  
Neeraja Konuthula ◽  
...  
Keyword(s):  
Gene Expression ◽  
De Novo ◽  
Conflicts Of Interest ◽  
Noncoding Rnas ◽  
Cell Types ◽  
Long Noncoding Rnas ◽  
Read Length ◽  
Rna Seq ◽  
Erythroid Progenitors ◽  
Specific Expression

Abstract Abstract 2331 Lnc (long noncoding) RNAs are RNA transcripts greater than 200nt that regulate gene expression independent of protein coding potential. It is estimated that thousands of lncRNAs play vital roles in diverse cellular processes and are involved in numerous diseases, including cancer. We hypothesize that multiple lncRNAs regulate erythrocyte and megakaryocyte formation by modulating gene expression. To identify lncRNAs in erythro-megakaryopoiesis, we purified two biological replicates each of murine Ter119+ erythroblasts, CD41+ megakaryocytes and bipotential megakaryocyte-erythroid progenitors (MEPs) [Lin− Kit+, Sca1−, CD16/32−, CD34−]. We performed strand-specific, paired-end, 200nt-read-length deep sequencing (RNA-Seq) to a depth of ∼200 million reads per sample using the Illumina GAII platform. We used the Tophat and Cufflinks suite of bioinformatic tools to assemble and compare de-novo transcriptomes from these three cell types, producing a high-confidence set of 69,488 transcripts. We confirmed that the RNA-seq assemblies accurately reflect gene expression predicted from prior studies. For example, Ter119+ cells were highly enriched for key erythroid transcripts encoding globins, heme synthetic enzymes and specialized membrane proteins. Megakaryocytes expressed high levels of gene encoding lineage-specific integrins and platelet markers. MEPs expressed numerous progenitor genes including Gata2, Kit and Myc. Thus, the RNA-seq data are of high-quality and sufficient complexity to accurately represent erythroid, megakaryocytic and MEP transcriptomes. We used a series of Unix-based bioinformatic filtering tools to identify lncRNAs that are expressed in these transcriptomes. We identified 605 “stringent” lncRNAs, and 813 “potential noncoding” transcripts. 47% of the lncRNAs are novel unannotated transcripts, validating the use of de-novo RNA-Seq in unique cell populations for lncRNA discovery. Among the 605 “stringent” lncRNAs, 103 are erythroid-restricted, 133 are meg-restricted and 280 are MEP-restricted, consistent with reports that lncRNAs exhibit exquisitely cell-type specific expression. Current efforts are aimed at generating a more comprehensive map of lncRNA expression at specific stages of erythroid and megakaryocyte/platelet development, and performing high throughput functional screens to analyze currently identified lncRNAs. Our studies are beginning to define new layers of gene regulation in normal erythro-megakaryopoiesis and are relevant to the pathophysiology of related disorders including various anemias, myeloproliferative and myelodysplastic syndromes and leukemias. Disclosures: No relevant conflicts of interest to declare.

Estradiol Induces Gene Proximity and MLL-MLLT3 Fusion In An AICDA-Mediated Pathway

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 806-806
Author(s):  
Andrew T Vaughan ◽  
Rebecca Wright ◽  
Katrina Slemmons
Keyword(s):  
Acute Leukemia ◽  
Dna Cleavage ◽  
De Novo ◽  
Conflicts Of Interest ◽  
Hot Spot ◽  
Clinical Samples ◽  
Common Mechanism ◽  
Mll Gene ◽  
Increased Risk ◽  
Translocation Breakpoints

Abstract Translocation breakpoints involving the MLL gene linked to Infant Acute Leukemia (IAL) and therapy related acute leukemia (tAL) are tightly clustered between MLL exons 8 and 12. Exon 12 also marks the location of a well-described cleavage hotspot that is synchronous with a sharp decline in total MLL fusions observed in clinical samples. Though multiple MLL fusion partners have been identified, fusions to MLLT3 (AF9) and AFF1 (AF4) comprise 56% of all clinical rearrangements so far assayed. Epidemiological data has linked maternal exposure to birth control formulations with an increased risk of IAL involving MLL gene rearrangements. Subsequent in-vitro studies suggested a role of estradiol (E2) in the generation of such rearrangements. In order to probe the action of E2 in generating these lesions, the ability of E2 to impact MLL rearrangement formation was studied, focusing on the exon 12 hotspot and using immortalized but not transformed TK6 lymphoblastoid cells. Real-time PCR studies showed that in this cell line, transient exposure to 10 nM E2 enhanced transcription of MLL eight fold over controls. E2 treatment also increased transcription of MLL partner genes, MLLT3 and AFF1, through to a lesser degree. To determine if the process of transcription led to gene co-localization, chromatin conformation capture (3C) experiments were performed. Here, brief exposure to 10 nM E2 led to the co-localization of MLL with MLLT3, using primer sets targeting both MLL introns 9 and 13 and MLLT3 introns 4 and 8. These data indicated contact between these two genes, over a substantial region, consistent with their occupation of an operationally defined “transcription factory”. Surprisingly, low levels of E2 also stimulated the generation of de-novo MLL- MLLT3 fusion transcripts, without the application of any genotoxic stressors. To identify the process whereby each gene is fragmented, an essential precursor to any rearrangement, RNAi knockdown of activation induced cytidine deaminase (AICDA) was studied. AICDA activity is normally associated with class switch recombination and somatic hypermutation, but has recently been identified as the fragmenting agent associated with c-myc/IgH fusions in Burkitts lymphoma. RNAi knockdown of AICDA suppressed the induction of MLL-MLLT3 fusion transcript formation observed with E2 treatment, suggesting AICDA involvement in MLL and partner gene fragmentation. To probe this association in more detail, a ChIP analysis was performed targeting AICDA recruitment to MLL intron 11 (hot spot for rearrangements) or intron 12 (few MLL rearrangements). Here, E2 dependent localization of AICDA was noted upstream of the DNA cleavage hotspot and within the region of elevated MLL fusions in intron 11, but not in a region showing few rearrangements. Combined, these studies show that concentrations of E2 that occur during pregnancy, or during use of oral contraceptives, have the potential to initiate MLL fusions through an endogenous AICDA-mediated mechanism, that is enhanced by gene proximity associated with synchronous transcription of both MLL and partner genes. Further, the link between transcription-induced co-localization and MLL rearrangements may identify a common mechanism of MLL fusion gene formation relevant to a wider range of clinical diagnoses. If correct, then this mechanism may be a target for manipulation, particularly in controlled settings such as the delivery of potentially leukemogenic therapeutics. Disclosures: No relevant conflicts of interest to declare.

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