Fusion of the TEL gene on 12p13 to the AML1 gene on 21q22 in acute lymphoblastic leukemia.

Chromosomal rearrangements involving band 12p13 are found in a wide variety of human leukemias but are particularly common in childhood acute lymphoblastic leukemia. The genes involved in these rearrangements, however, have not been identified. We now report the cloning of a t(12;21) translocation breakpoint involving 12p13 and 21q22 in two cases of childhood pre-B acute lymphoblastic leukemia, in which t(12;21) rearrangements were not initially apparent. The consequence of the translocation is fusion of the helix-loop-helix domain of TEL, an ETS-like putative transcription factor, to the DNA-binding and transactivation domains of the transcription factor AML1. These data show that TEL, previously shown to be fused to the platelet-derived growth factor receptor beta in chronic myelomonocytic leukemia, can be implicated in the pathogenesis of leukemia through its fusion to either a receptor tyrosine kinase or a transcription factor. The TEL-AML1 fusion also indicates that translocations affecting the AML1 gene can be associated with lymphoid, as well as myeloid, malignancy.

Dissecting the signaling mechanisms of IL-7-mediated autophagy regulation in T-cell acute lymphoblastic leukemia

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Increased fibrinogen levels at diagnosis are associated with adverse outcome in patients with acute myeloid leukemia

Increased plasma fibrinogen levels are associated with shortened overall survival (OS) in some solid tumor types. In contrast, the prognostic significance of varying fibrinogen levels in acute myeloid leukemia (AML) at diagnosis is unknown. In this study, we assessed the prognostic significance of fibrinogen levels in AML patients. In a comprehensive retrospective single-center study, we determined the survival rates of 375 consecutive AML patients undergoing at least one cycle of intensive chemotherapy induction treatment. Patients were dichotomized between low (<4.1 g/L) and high fibrinogen levels (≥4.1 g/L) at diagnosis of AML before initiation of treatment. Subsequently, quartile ranges were applied to analyze the association of varying fibrinogen levels on survival. We observed that the rates of complete remission, early death, and admission to intensive care unit were equal in the low versus high fibrinogen group. However, OS was significantly better in the low fibrinogen group (27.3 vs 13.5 months; p = 0.0009) as well as progression-free survival (12.3 vs 7.8 months; p = 0.0076). This survival difference remained significant in the multivariate analysis (p = 0.003). Assessing quartiles of fibrinogen values, we further confirmed this observation. Our data suggest that high fibrinogen levels at diagnosis of AML are associated with unfavorable OS and progression-free survival but not with increased mortality during induction treatment.

Long-term outcome after intensive therapy with etoposide, melphalan, total body irradiation and autotransplant for acute myeloid leukemia

Intensive therapy and autologous blood and marrow transplantation (ABMT) is an established post-remission treatment for acute myeloid leukemia (AML), although its exact role remains controversial and few data are available regarding longer-term outcomes. We examined the long-term outcome of patients with AML transplanted at a single center using uniform intensive therapy consisting of etoposide, melphalan and TBI. In all, 145 patients with AML underwent ABMT: 117 in first remission, 21 in second remission and seven beyond second remission. EFS and OS were significantly predicted by remission status (P

Disseminated Scedosporium prolificans infection and survival of a child with acute lymphoblastic leukemia

Scedosporium prolificans is a saprophytic fungus responsible for an increasing number of infections among immumocompromised hosts. Historically, disseminated infection with this organism has resulted in death. We report on a pediatric patient who developed overwhelming S. prolificans sepsis after induction chemotherapy for acute lymphoblastic leukemia. She is well 18 months after the diagnosis of fungal sepsis and continues to receive chemotherapy for leukemia, which remains in remission.

Body composition in children in remission from acute lymphoblastic leukemia

Background: Changes in body composition are commonly reported in pediatric survivors of acute lymphoblastic leukemia (ALL). However, the effect of ALL and of its treatment on body composition in children in remission from ALL has not been fully examined with the use of a reference method. Objectives: We aimed to determine the body composition and composition of fat-free mass (FFM) in children in remission from ALL. We also aimed to compare the effects that prednisolone and dexamethasone had on the body composition of an ALL survivor population. Design: This cross-sectional study measured height, weight, body volume, total body water, and bone mineral content in 24 children in remission from ALL and 24 age-matched, healthy control subjects. Body composition and FFM composition were evaluated by using the 4-component model. Results: The mean body mass index and fat mass index were significantly (P = 0.05 for both) higher in the ALL survivors than in age-matched control subjects. The composition of the FFM in the 2 treatment groups was not observed to differ significantly. Examination of the composition of FFM made it evident that children in remission from ALL had both significantly greater hydration (P = 0.001) and lower density (P = 0.0001) of FFM than did the control children. Conclusions: Children in remission from ALL may develop excess body fat. To measure body composition accurately in an ALL population, the high hydration and low density of FFM in this population should be taken into consideration.

Prevention of oral lesions in children with acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common form of cancer in children and is responsible for severe stomatologic complications. Treatment consists of four phases of chemotherapy, the main side effect of methotrexate, the drug most used during the intensification phase, is oral mucositis. OBJECTIVE: To evaluate the clinical aspects of the oral mucosa of children with ALL and to determine the effect of 0.12% chlorhexidine gluconate on the prevention of stomatologic complications in these patients. PATIENTS AND METHODS: Thirty-three children treated for ALL ranging in age from 2 to 15 years, without distinction of gender or race, were submitted to visual examination, digital palpation of the oral mucosa and cytologic examination of the buccal mucosa, and divided into two groups: group I consisted of 23 children using an oral solution of 0.12% chlorhexidine gluconate twice a day, and group II consisted of 10 children who did not receive this solution. All children received daily oral hygiene care guided by the dentist throughout treatment. RESULTS: Mucositis was observed in six children of group I and eight of group II, and was characterized by erythema, edema and ulcers. Uniform cytologic findings were obtained for the two groups, with a clear predominance of cells of the intermediate layer in all smears, in addition to a perinuclear halo in 18% of the smears. CONCLUSION: The present results suggest that systematic preventive treatment with 0.12% chlorhexidine gluconate and oral hygiene care reduce the occurrence of oral complications in children with ALL undergoing antineoplastic chemotherapy.

Prevention of oral lesions in children with acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common form of cancer in children and is responsible for severe stomatologic complications. Treatment consists of four phases of chemotherapy, the main side effect of methotrexate, the drug most used during the intensification phase, is oral mucositis. OBJECTIVE: To evaluate the clinical aspects of the oral mucosa of children with ALL and to determine the effect of 0.12% chlorhexidine gluconate on the prevention of stomatologic complications in these patients. PATIENTS AND METHODS: Thirty-three children treated for ALL ranging in age from 2 to 15 years, without distinction of gender or race, were submitted to visual examination, digital palpation of the oral mucosa and cytologic examination of the buccal mucosa, and divided into two groups: group I consisted of 23 children using an oral solution of 0.12% chlorhexidine gluconate twice a day, and group II consisted of 10 children who did not receive this solution. All children received daily oral hygiene care guided by the dentist throughout treatment. RESULTS: Mucositis was observed in six children of group I and eight of group II, and was characterized by erythema, edema and ulcers. Uniform cytologic findings were obtained for the two groups, with a clear predominance of cells of the intermediate layer in all smears, in addition to a perinuclear halo in 18% of the smears. CONCLUSION: The present results suggest that systematic preventive treatment with 0.12% chlorhexidine gluconate and oral hygiene care reduce the occurrence of oral complications in children with ALL undergoing antineoplastic chemotherapy.

Inter-Laboratory Evaluation of a Next-Generation Sequencing Panel for Acute Myeloid Leukemia

INTRODUCTION: Acute myeloid leukemia (AML) is a heterogeneous clonal disorder often associated with dismal overall survival. The clinical diversity of AML is reflected in the range of recurrent somatic mutations in several genes, many of which have a prognostic and therapeutic value. Targeted next-generation sequencing (NGS) of these genes has the potential for translation into clinical practice. In order to assess this potential, an inter-laboratory evaluation of a commercially available AML gene panel across three diagnostic centres in the UK and Ireland was performed.

METHODS: DNA from six AML patient samples was distributed to each centre and processed using a standardised workflow, including a common sequencing platform, sequencing chips and bioinformatics pipeline. A duplicate sample in each centre was run to assess inter- and intra-laboratory performance.

RESULTS: An average sample read depth of 2725X (range 629-5600) was achieved using six samples per chip, with some variability observed in the depth of coverage generated for individual samples and between centres. A total of 16 somatic mutations were detected in the six AML samples, with a mean of 2.7 mutations per sample (range 1-4) representing nine genes on the panel. 15/16 mutations were identified by all three centres. Allelic frequencies of the mutations ranged from 5.6 to 53.3 % (median 44.4 %), with a high level of concordance of these frequencies between centres, for mutations detected.

CONCLUSION: In this inter-laboratory comparison, a high concordance, reproducibility and robustness was demonstrated using a commercially available NGS AML gene panel and platform.

Specific JAK2 mutation (JAK2R683) and multiple gene deletions in Down syndrome acute lymphoblastic leukemia

Children with Down syndrome (DS) have a greatly increased risk of acute megakaryoblastic leukemia (AMKL) and acute lymphoblastic leukemia (ALL). Both DS-AMKL and the related transient myeloproliferative disorder (TMD) have GATA1 mutations as obligatory, early events. To identify mutations contributing to leukemogenesis in DS-ALL, we undertook sequencing of candidate genes, including FLT3, RAS, PTPN11, BRAF, and JAK2. Sequencing of the JAK2 pseudokinase domain identified a specific, acquired mutation, JAK2R683, in 12 (28%) of 42 DS-ALL cases. Functional studies of the common JAK2R683G mutation in murine Ba/F3 cells showed growth factor independence and constitutive activation of the JAK/STAT signaling pathway. High-resolution SNP array analysis of 9 DS-ALL cases identified additional submicroscopic deletions in key genes, including ETV6, CDKN2A, and PAX5. These results infer a complex molecular pathogenesis for DS-ALL leukemogenesis, with trisomy 21 as an initiating or first hit and with chromosome aneuploidy, gene deletions, and activating JAK2 mutations as complementary genetic events. (Blood. 2009; 113: 646-648)

Emergency emicolectomy for intestinal primary Aspergillosis in acute myeloid leukemia

ntestinal aspergillosis is an infection with a very high death rate especially in leukemic patients. Here we describe a case of a 46 years old woman with acute myeloid leukemia (LAM M5) who developed intestinal primary aspergillosis. This patient was diagnosed with LAM M5 through bone marrow aspiration and bone biopsy in March 2004. Symptoms of the disease were slight persistent fever, weight loss, asthenia, anemia, thrombocytopenia,and leukocytosis with high number of blasts in peripheral blood. After induction chemotherapy with ICE (Ifosfamide, Carboplatin, Etoposide), she developed neutropenia and high fever without apparent infective foci. She was treated with empiric antibiotic therapy, nevertheless she developed an intense diarrhea and ileo-cecal distention. Diagnostic exams didn’t show signs of a focal lesion. Despite the change in antibiotic treatment and the transfusions of granulocytes and blood cells, the patient developed extremely critical conditions with persistence of neutropenia and abdominal distention. A surgical treatment was decided at the time. We treated the patient with a two steps surgical procedure. The first step was a right abdominal ileostomy followed by improvement of general conditions and then the second step a right colectomy. The histological morphology confirmed necrotizing colitis with Aspergillus ife. At that time , treatment with voriconazole was started. The general conditions of the patient improved rapidly and we were able to treat the patient with other medical anti-leukemic therapies. The patient is now cured and in healthy state. We obtained a good clinical result as only in other few cases described in literature.

Proscillaridin A effects on histone acetylation and C-MYC degradation in acute lymphoblastic leukemia

La leucémie lymphoblastique aiguë (LLA) représente environ 25% des cancers pédiatriques diagnostiqués chaque année. Dans 80 % des cas, une rémission complète est observée. Cependant, les patients résistants aux traitements ainsi que les patients en rechute présentent un mauvais pronostique. Les altérations épigénétiques sont des facteurs essentiels dans le développement et la progression de la maladie, ainsi qu’à la résistance aux traitements. Lors d’un criblage de médicaments approuvés par la FDA, nous avons découvert des molécules ayant des caractéristiques anticancéreux et épigénétiques. Pour évaluer l’activité de ces molécules, nous avons procédé à un criblage secondaire sur plusieurs lignées cellulaires leucémiques. Nous avons découvert qu’une de ces molécules, un glucoside cardiotonique appelé la proscillaridine A, avait une activité anticancéreuse spécifique pour des cellules leucémiques. Nous faisons donc l’hypothèse que la proscillaridine A pourrait avoir des effets épigénétiques et anticancéreux dans des modèles précliniques de LLA. Pour tester cette hypothèse, nous avons traité deux lignées cellulaires de LLA Nalm-6 (LLA pre-B) et Molt-4 (T-LLA) in vitro pendant 2 à 96 heures à des doses pertinentes sur le plan clinique. Nous avons alors pu observer une inhibition de croissance qui était dépendante de la dose administrée dans les deux lignées cellulaires, avec des valeurs de 50% d’inhibition de croissance (CI50) de 3.0 nM pour les Nalm-6 et de et 2.3 nM pour les Molt-4. De plus, nos études sur le cycle cellulaire par BrdU démontrent un arrêt en phase G2/M. Nous avons également détecté par immunobuvardage de type western des baisses significatives de l’acétylation de résidus de l’histone 3. Les niveaux d’expression des enzymes responsables de cette acétylation, les histones acétyltransférases CBP, P300 et TIP60 ainsi que de l’oncogène C-MYC étaient également diminuées. Par des analyses de séquençage de l’ARN, nous avons observé une augmentation de l’expression des gènes impliquées dans les processus d’apoptose et de différentiation cellulaire, ainsi qu’une diminution des gènes impliqués dans la prolifération cellulaire comme en particulier les gènes cibles de C-MYC. Ces résultats prometteurs suggèrent le potentiel prometteur de la proscillaridine A comme nouvelle thérapie pour les patients atteints de LLA.