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Sci Rep ; 11(1): 21689, 2021 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-34737376


The mechanistic target of rapamycin (mTOR) is a kinase whose activation is associated with poor prognosis in pre-B cell acute lymphoblastic leukemia (B-ALL). These and other findings have prompted diverse strategies for targeting mTOR signaling in B-ALL and other B-cell malignancies. In cellular models of Philadelphia Chromosome-positive (Ph+) B-ALL, mTOR kinase inhibitors (TOR-KIs) that inhibit both mTOR-complex-1 (mTORC1) and mTOR-complex-2 (mTORC2) enhance the cytotoxicity of tyrosine kinase inhibitors (TKIs) such as dasatinib. However, TOR-KIs have not shown substantial efficacy at tolerated doses in blood cancer clinical trials. Selective inhibition of mTORC1 or downstream effectors provides alternative strategies that may improve selectivity towards leukemia cells. Of particular interest is the eukaryotic initiation factor 4F (eIF4F) complex that mediates cap-dependent translation. Here we use novel chemical and genetic approaches to show that selective targeting of either mTORC1 kinase activity or components of the eIF4F complex sensitizes murine BCR-ABL-dependent pre-B leukemia cells to dasatinib. SBI-756, a small molecule inhibitor of eIF4F assembly, sensitizes human Ph+ and Ph-like B-ALL cells to dasatinib cytotoxicity without affecting survival of T lymphocytes or natural killer cells. These findings support the further evaluation of eIF4F-targeted molecules in combination therapies with TKIs in B-ALL and other blood cancers.

J Pediatr Genet ; 9(3): 203-206, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32714623


Severe neutropenia is defined as an absolute neutrophil count (ANC) of less than 0.5 × 10 9 /L. Severe congenital neutropenia (SCN) is an inborn disorder with maturation arrest of granulocytes due to various genetic abnormalities, which may lead to immunodeficiency. Among several associated genetic mutations, the variants or heterozygous mutations of the ELANE gene coding neutrophil elastase comprise approximately 50% of the genetic causes of SCN. We present a newborn (male) with severe neutropenia due to a novel ELANE gene mutation. The newborn was born at 38 6/7 weeks gestation to a 25-year-old mother with hypertension and morbid obesity. Pregnancy and delivery were uncomplicated but the baby obtained a complete blood count (CBC) on day of life 2 for a work up of hyperbilirubinemia. He was noted to initially have an ANC of 0.2 × 10 9 /L and 0 on subsequent blood counts. A bone marrow biopsy showed a left shift and consistent with myeloid maturation arrest. In direct DNA sequencing analysis, we found an ELANE gene mutation (Val119Glu, V119E), which may be a new gene mutation to cause SCN. The diagnosis of SCN in newborns is usually based on neutropenia identified on a routine CBC. Sufficient awareness and high suspicion of this rare disease can prevent missed or delayed diagnosis of SCN. Our analysis also suggests a new pathological mutation in the ELANE gene and supports the important role of molecular testing in SCN.

J Pediatr Hematol Oncol ; 42(8): 474-481, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32282650


The Ewing sarcoma family of tumors (ESFT) are high-grade small round blue cell malignancies traditionally presenting in children and adolescents. The most common site of primary disease is bone, though extraskeletal primary sites are well-recognized. We present 6 cases of primary ESFT of the kidney and 1 case of the adrenal gland. Patients were 11 to 18 years of age at diagnosis. Metastases at diagnosis were present in most cases (n=6). All patients underwent surgery, and most received radiation (n=5). Five patients relapsed after initial remission. Comprehensive review of the primary renal ESFT literature was used to analyze various factors, including age, sex, disease metrics, metastases at diagnoses, and overall survival in a total of 362 cases. Notably, while the general ESFT population has reported rates of metastasis at diagnosis of 20% to 25%, this rate in the renal ESFT population was 53% with a rate of 59% in adolescent and young-adult patients (11 to 24 y). Nodal disease at diagnosis was present in 24% of renal ESFT cases compared with 3.2% in patients with primary skeletal ESFT. While this malignant process may share histologic and molecular features with its bone and soft tissue counterparts, primary renal ESFT presentations seem to be more aggressive and have worse outcomes.

Neoplasias Renais/patologia , Sarcoma de Ewing/patologia , Adolescente , Criança , Feminino , Humanos , Neoplasias Renais/genética , Neoplasias Renais/mortalidade , Neoplasias Renais/terapia , Masculino , Sarcoma de Ewing/genética , Sarcoma de Ewing/mortalidade , Sarcoma de Ewing/terapia
J Pediatr Hematol Oncol ; 42(6): e491-e493, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-31764515


Langerhans cell histiocytosis (LCH) is the most common histiocytic disorder, characterized by the pathologic clonal proliferation and accumulation of immature Langerhans cells within organs. Multiple organ systems can be affected, resulting in a spectrum of clinical manifestations. Isolated gastrointestinal involvement in LCH is rare and usually presents in childhood as a multisystem disease and usually has poor outcomes. We describe a 20-year-old Hispanic female with multifocal, single-system gastrointestinal LCH. Initially diagnosed from a CD1a, S100, and CD207 (Langerin) positive appendix tissue after an appendectomy and confirmed multifocal with an endoscopy. She had a full clinical and endoscopic resolution of disease with cytarabine therapy.

Gastroenteropatias/patologia , Histiocitose de Células de Langerhans/patologia , Adulto , Antimetabólitos Antineoplásicos/uso terapêutico , Citarabina/uso terapêutico , Feminino , Gastroenteropatias/complicações , Gastroenteropatias/tratamento farmacológico , Histiocitose de Células de Langerhans/complicações , Histiocitose de Células de Langerhans/tratamento farmacológico , Humanos , Prognóstico , Adulto Jovem
Oncotarget ; 9(5): 6562-6571, 2018 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-29464092


High-risk subtypes of B-cell acute lymphoblastic leukemia (B-ALL) include Philadelphia chromosome-positive (Ph+) B-ALL driven by the BCR-ABL1 oncogene and a more recently identified subtype known as BCR-ABL-like or Ph-like B-ALL. A hallmark of both Ph+ and Ph-like B-ALL is constitutive activation of tyrosine kinase signaling that is potentially targetable with tyrosine kinase inhibitors (TKIs). B-ALL cells also receive extracellular signals from the microenvironment that can maintain proliferation and survival following treatment with TKIs. Therefore, there is strong rationale for combining TKIs with other therapies targeting signal transduction pathways. Here we show that combinations of the ABL-directed TKI dasatinib with mTOR kinase inhibitors (TOR-KIs) are more effective than TKI alone against patient-derived Ph-like B-ALL cells harboring rearrangements of ABL1 or ABL2. We also report the establishment of a new human Ph-like B-ALL cell line that is stromal cell-independent in vitro and can be used for xenograft experiments in vivo. These findings provide rationale for clinical testing of TKI plus TOR-KIs in children and adults with Ph-like B-ALL and a new experimental tool to test promising therapeutic strategies in this poor prognosis subtype of B-ALL.

Exp Mol Pathol ; 103(3): 263-266, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29155023


BACKGROUND: Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy. Acute myeloid leukemia or myelodysplastic syndrome during the course of ALL is a rare entity. Some of these cases are therapy-related while the others occur due to lineage switch. The correct diagnosis relies on comparing the immunophenotypes and cytogenetic/molecular alterations of the myeloid neoplasm and the ALL. We present the clinical, pathologic and cytogenetic features of a case of an 18-year-old male with prior treatment for B-lymphoblastic leukemia (B-ALL) who developed therapy-related myeloid neoplasm (t-MN) 4-5years after his initial diagnosis of B-ALL. CASE PRESENTATION: A 13-year-old boy with no significant past medical history presented to Harbor-UCLA Medical Center (HUMC) in November 2012 with night sweats, fevers and chills, nausea, vomiting, diarrhea, fatigue, weakness, and weight loss. Peripheral blood flow cytometric analysis disclosed B-ALL. The blasts expressed CD10, CD19, CD22 (dim), CD34, CD38, HLA-DR, and TdT, and were negative for CD20, CD13, CD33, CD117, and cytoplasmic MPO. Chromosomal analysis and a supplemental fluorescence in situ hybridization (FISH) study performed on the bone marrow aspirate showed an abnormal karyotype (47,XY,+X,del(9)(p21p21)[4]/46,XY[16]). He achieved remission after induction chemotherapy and remained in remission until March 2016 when bilateral testicular masses were noted. Biopsy of the left testicular mass showed relapsed B-ALL. Cerebrospinal fluid (CSF) contained rare TdT-positive blasts, suggestive of minimal/early involvement by B-ALL. However, there was no evidence of acute leukemia in his bone marrow at this time. He was then treated with COG protocol AALL1331 randomized to blinatumomab arm and achieved second remission. In June 2017, the patient's peripheral blood smear showed 11% circulating monoblasts. By flow cytometry, the blasts expressed CD4, CD11b, CD13, CD15, CD33, CD38, CD56, and CD64. In addition, a few TdT-positive blasts were seen in his CSF cytospin smear. Bone marrow biopsy was subsequently performed which was consistent with evolving acute myeloid leukemia. A diagnosis of myeloid neoplasm, consistent with t-MN was made. Chromosomal analysis and FISH studies performed on his bone marrow aspirate showed normal karyotype (46,XY[20]), negative FISH result for deletion 9p21 locus, and positive KMT2A (MLL) rearrangement, respectively. Despite of chemotherapy, the patient died within one month after diagnosis. DISCUSSION AND CONCLUSION: Diagnosis of t-MN should be suspected in patients with a history of receiving cytotoxic agents and/or irradiation. In this case study, we diagnosed t-MN with KMT2A rearrangement in a patient with history of B-ALL with 9p deletion and gain of X chromosome. Unusual features associated with this case are discussed.

Histona-Lisina N-Metiltransferase/genética , Leucemia Mieloide Aguda/genética , Proteína de Leucina Linfoide-Mieloide/genética , Segunda Neoplasia Primária/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Adolescente , Cromossomos Humanos Par 9/genética , Cromossomos Humanos X/genética , Regulação Leucêmica da Expressão Gênica , Humanos , Hibridização in Situ Fluorescente , Quimioterapia de Indução/efeitos adversos , Leucemia Mieloide Aguda/induzido quimicamente , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/patologia , Masculino , Proteínas de Neoplasias/genética , Segunda Neoplasia Primária/induzido quimicamente , Segunda Neoplasia Primária/diagnóstico , Segunda Neoplasia Primária/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicações , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia