Ultraconserved long non-coding RNA uc 112 is highly expressed in childhood T versus B-cell acute lymphoblastic leukemia

ABSTRACT Aberrant expression of long non-coding RNAs (lncRNAs) has been detected in several types of cancer, including acute lymphoblastic leukemia (ALL), but lncRNA mapped on transcribed ultraconserved regions (T-UCRs) are little explored. The T-UCRs uc.112, uc.122, uc.160 and uc.262 were evaluated by quantitative real-time PCR in bone marrow samples from children with T-ALL (n = 32) and common-ALL/pre-B ALL (n = 30). In pediatric ALL, higher expression levels of uc.112 were found in patients with T-ALL, compared to patients with B-ALL. T-cells did not differ significantly from B-cells regarding uc.112 expression in non-tumor precursors from public data. Additionally, among B-ALL patients, uc.112 was also found to be increased in patients with hyperdiploidy, compared to other karyotype results. The uc.122, uc.160, and uc.262 were not associated with biological or clinical features. These findings suggest a potential role of uc.112 in pediatric ALL and emphasize the need for further investigation of T-UCR in pediatric ALL.

Moyamoya syndrome associated with neurofibromatosis type I in a pediatric patient / Síndrome de moyamoya associada a neurofibromatose tipo I em paciente pediátrico

CONTEXT: Neurofibromatosis type 1 (NF-1) is the most prevalent autosomal dominant genetic disorder among humans. Moyamoya disease is a cerebral vasculopathy that is only rarely observed in association with NF-1, particularly in the pediatric age range. The present study reports an occurrence of this association in an infant. CASE REPORT: An eight-month-old female presented convulsive seizures with clonic movements. The patient suffered an ischemic stroke with hemiparesis. Magnetic resonance imaging revealed radiological findings compatible with moyamoya disease. The diagnosis of NF-1 was made at the age of 20 months. CONCLUSION: Despite the rarity of this association in childhood, children with focal neurological symptoms and a diagnosis of NF-1 deserve to be investigated for moyamoya syndrome.

CONTEXTO: Neurofibromatose tipo 1 (NF-1) é a doença genética autossômica dominante mais prevalente no ser humano. A doença de moyamoya é uma vasculopatia cerebral que raramente se encontra associada à NF-1, particularmente na faixa etária pediátrica. Este estudo descreve a ocorrência desta associação em um lactente. RELATO DE CASO: Paciente feminina, aos oito meses de idade, apresentou quadro de crise convulsiva com movimentos clônicos. Evoluiu com acidente vascular encefálico isquêmico e com hemiparesia à direita. Ressonância nuclear magnética mostrou achados compatíveis com a doença de moyamoya. O diagnóstico de NF-1 foi realizado aos 20 meses de vida. CONCLUSÃO: Apesar da raridade desta associação na faixa etária infantil, crianças com sintomas neurológicos focais e diagnóstico de NF-1 merecem ser investigadas para síndrome de moyamoya.

Antiproliferative effects of Tubi-bee propolis in glioblastoma cell lines

Propolis is a resin formed by a complex chemical composition of substances that bees collect from plants. Since ancient times, propolis has been used in folk medicine, due to its biological properties, that include antimicrobial, anti-inflammatory, antitumoral and immunomodulatory activities. Glioblastoma is the most common human brain tumor. Despite the improvements in GBM standard treatment, patients' prognosis is still very poor. The aim of this work was to evaluate in vitro the Tubi-bee propolis effects on human glioblastoma (U251 and U343) and fibroblast (MRC-5) cell lines. Proliferation, clonogenic capacity and apoptosis were analyzed after treatment with 1 mg/mL and 2 mg/mL propolis concentrations for different time periods. Additionally, glioblastoma cell lines were submitted to treatment with propolis combined with temozolomide (TMZ). Data showed an antiproliferative effect of tubi-bee propolis against glioblastoma and fibroblast cell lines. Combination of propolis with TMZ had a synergic antiproliferative effect. Moreover, propolis caused decrease in colony formation in glioblastoma cell lines. Propolis treatment had no effects on apoptosis, demonstrating a cytostatic action. Further investigations are needed to elucidate the molecular mechanism of the antitumor effect of propolis, and the study of its individual components may reveal specific molecules with antiproliferative capacity.

Multiple drug resistance protein (MDR-1), multidrug resistance-related protein (MRP) and lung resistance protein (LRP) gene expression in childhood acute lymphoblastic leukemia

CONTEXTO: Apesar dos avanços nos índices de cura da leucemia linfoblástica aguda (LLA) aproximadamente 25% das crianças sofrem recaídas da doença. A expressão dos genes de resistência múltipla a drogas (MDR-1), genes relacionados à proteína de resistência múltipla a drogas (MRP) e genes da proteína de resistência pulmonar (LRP) podem conferir o fenótipo de resistência ao tratamento das neoplasias. OBJETIVO: Analisar a expressão dos genes de resistência MDR-1, MRP e LRP em crianças diagnosticadas com LLA por meio da técnica da reação em cadeia da polimerase da transcriptase reversa (RT-PCR) semiquantitativa, associando estas expressões à sobrevida livre de eventos (SLE) e a variáveis clínico-laboratoriais. TIPO DE ESTUDO: Estudo clínico retrospectivo. LOCAL: Laboratório de Oncologia Pediátrica do Departamento de Puericultura e Pediatria da Faculdade de Medicina de Ribeirão Preto - Universidade de São Paulo, Brasil. MÉTODOS: Amostras de medula óssea de 30 crianças com o diagnóstico de leucemia linfoblástica aguda foram avaliadas quanto à expressão do RNA-mensageiro para os genes MDR-1, MRP e LRP, pela reação em cadeia da RT-PCR semiquantitativa. RESULTADOS: Dos três genes estudados, somente a expressão aumentada de LRP esteve relacionada a uma pior SLE (p = 0.005). A presença do antígeno para leucemia linfoblástica aguda comum (CALLA) se correlacionou à expressão aumentada de LRP (p = 0.009) e a risco aumentado de ocorrência de recaída ou óbito (p = 0.05). O risco relativo de ocorrência de recaída ou óbito é seis vezes maior em crianças com alta expressão de LRP ao diagnóstico (p = 0.05), o que se confirma na análise multivariada dos três genes estudados (p = 0.035). DISCUSSAO: A resistência celular a drogas é um determinante de resposta ao tratamento oncológico e sua avaliação por RT-PCR pode ser de importância. CONCLUSÕES: A avaliação da expressão dos genes de resistência a drogas antineoplásicas na leucemia linfoblástica aguda da criança ao diagnóstico, particularmente do gene LRP, pode ser de relevância clínica e deve ser objeto de estudos prospectivos.

Inactivation of the p15 gene in children with acute lymphoblastic leukemia

CONTEXT: Tumor suppressor genes act on the control of cell cycle progression. In pediatric neoplasias, some of these genes may be considered to be markers for diagnosis or relapse, thus probably representing prognostic indicators. OBJECTIVE: To study the inactivation of the p15 gene in children with acute lymphoblastic leukemia. TYPE OF STUDY: Retrospective study. SETTING: Laboratory of Molecular Biology, Department of Pediatrics, Faculdade de Medicina de Ribeiräo Preto, Universidade de Säo Paulo. PARTICIPANTS: Eighty-three children and adolescents with acute lymphoblastic leukemia were studied, with the examination of 83 bone marrow samples obtained at diagnosis, four obtained also during relapse, and two cerebrospinal fluid samples obtained from two cases of isolated relapse in the central nervous system. MAIN MEASUREMENTS: Homologous deletion of the p15 gene by multiplex polymerase chain reaction, and screening for point mutations by polymerase chain reaction/single-strand conformational polymorphism. RESULTS: Deletion of exon 2 of the p15 gene was observed in 15 children, including one case in which deletion was only verified during isolated central nervous system relapse. No case of exon 1 deletion, or that was suggestive of point mutations, was observed and no association between p15 gene inactivation and classic risk factors was established. CONCLUSION: According to the literature, inactivation of the p15 gene by deletion of exon 2 in acute lymphoblastic leukemia found in the population studied would be considered to be a molecular marker for diagnosis or relapse. However, no correlation between p15 gene deletion and clinical prognostic indicators was observed

Analysis of p16 gene mutations and deletions in childhood acute lymphoblastic leukemias

CONTEXT: The p16 tumor suppressor gene encodes a cyclin-dependent kinase 4 inhibitor that blocks cell division during the G1 phase of the cell cycle. Alterations in this gene have been reported for various neoplasia types, including acute lymphoblastic leukemias (ALL), especially T-cell acute lymphoblastic leukemias (ALL). OBJECTIVE: To determine probable alterations in the p16 gene in children with acute lymphoblastic leukemias using the polymerase chain reaction (PCR) and direct DNA sequencing and also to analyze event-free survival (EFS). DESIGN: Retrospective study. SETTING: Department of Child Care and Pediatrics, Faculty of Medicine of Ribeirão Preto, Universidade Federal de São Paulo. PARTICIPANTS: Fifty-six children with ALL (mean age 4 years). Forty (71.43 percent) had B-cell and 12 (21.43 percent) had T-cell ALL; 4 (7.1 percent) were biphenotypic. SAMPLE: DNA samples were extracted from bone marrow upon diagnosis and/or relapse. In 2 T-cell cases, DNA from cerebrospinal fluid (CSF) was analyzed. MAIN MEASUREMENTS: Deletions or nucleotide substitutions in exons 1, 2 and 3 of the p16 gene were determined by PCR and nucleotide sequencing. Event-free survival was determined by the Kaplan-Meyer and log-rank test for patients carrying normal and altered p16. RESULTS: Deletions in exon 3 were observed in five cases. Abnormal migration in PCR was observed in seven cases for exon 1, six for exon 2, and five for exon 3. Mutations in exon 1 were confirmed by direct DNA sequencing in four cases and in exon 2 in two cases. The Kaplan-Meyer survival curves and the log-rank test showed no significant differences in 5-year EFS between children with normal or altered p16, or between patients with B-ALL carrying normal or altered p16 gene. Patients with T-ALL could not be evaluated via Kaplan-Meier due to the small number of cases. CONCLUSIONS: Our results, particularly regarding deletion frequency, agree with others suggesting that deletions in the p16 are initial events in leukemia genesis. The small number of samples did not allow stablishment of correlation between childhood ALL and the p16 point mutations found in our study. Kaplan-Meier analysis revealed no significant correlation between EFS and alterations in ALL. The p16 alterations frequency observed for B and T-ALL agreed with reports from other centers

Prognostic significance of bi/oligoclonality in childhood acute lymphoblastic leukemia as determined by polymerase chain reaction

CONTEXT: The CDR-3 region of heavy-chain immunoglobulin has been used as a clonal marker in the study of minimal residual disease in children with acute lymphoblastic leukemia. Southern blot and polymerase chain reaction studies have demonstrated the occurrence of bi/oligoclonality in a variable number of cases of B-lineage acute lymphoblastic leukemia, a fact that may strongly interfere with the detection of minimal residual disease. Oligoclonality has also been associated with a poorer prognosis and a higher chance of relapse. OBJECTIVES: To correlate bi/oligoclonality, detected by polymerase chain reaction in Brazilian children with B-lineage acute lymphoblastic leukemia with a chance of relapse, with immunophenotype, risk group, and disease-free survival. DESIGN: Prospective study of patientsÆ outcome. SETTING: Pediatric Oncology Unit of the University Hospital, Faculty of Medicine of Ribeiräo Preto, University of Säo Paulo. PARTICIPANTS: 47 children with acute lymphoblastic leukemia DIAGNOSTIC TEST: Polymerase chain reaction using consensus primers for the CDR-3 region of heavy chain immunoglobulin (FR3A, LJH and VLJH) for the detection of clonality. RESULTS: Bi/oligoclonality was detected in 15 patients (31.9 percent). There was no significant difference between the groups with monoclonality and biclonality in terms of the occurrence of a relapse (28.1 percent versus 26.1 percent), presence of CALLA+ (81.2 percent versus 80 percent) or risk group (62.5 percent versus 60 percent). Disease-free survival was similar in both groups, with no significant difference (p: 0.7695). CONCLUSIONS: We conclude that bi/oligoclonality was not associated with the factors investigated in the present study and that its detection in 31.9 percent of the patients may be important for the study and monitoring of minimal residual disease