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.

Clinical, demographic, anatomopathological, and molecular findings in patients with medulloblastoma treated in a single health facility / Achados clínicos, demográficos, anatomopatológicos e moleculares de portadores de meduloblastoma tratados em uma única instituição

ABSTRACT Objective: To describe the clinical, demographic, anatomopathological, molecular, and survival characteristics of patients with medulloblastoma. Methods: Retrospective study based on patient information obtained from the review of medical records. Overall and event-free survival were analyzed using the Kaplan-Meier estimator, and the curves were compared by the log-rank test. Results: Among the patients investigated, 70 were male (66%), and age at diagnosis ranged from 2 months to 22 years. The most frequent signs and symptoms were headache (80.8%) and vomiting (75.8%). Regarding treatment, most patients (63.2%) underwent complete surgical resection, with a predominance of classic histology (63.2%). The 5-year overall survival rate was 67.9%, and the 10-year rate was 64.2%. Patients with molecular profile characteristic of the wingless (WNT) subgroup had a better prognosis, with 5-year overall survival of 75%. Conclusions: The clinical, demographic, anatomopathological, and molecular characteristics of patients with medulloblastoma described in the present study were mostly similar to those reported in the literature. Patients submitted to complete tumor resection had better clinical outcomes than those who underwent incomplete resection/biopsy. Patients classified as high-risk showed worse overall and event-free survival than those in the standard-risk group, and the presence of metastasis at diagnosis was associated with recurrence.

RESUMO Objetivo: Descrever as características clínicas, demográficas, anatomopatológicas, moleculares e de sobrevida de pacientes portadores de meduloblastoma. Métodos: Estudo retrospectivo, no qual as informações dos pacientes foram obtidas pela revisão dos prontuários médicos. Análises de sobrevida global e de sobrevida livre de eventos foram realizadas por meio da construção de curvas de Kaplan-Meier e a comparação entre as curvas foi feita pelo teste log-rank. Resultados: Entre os pacientes analisados, 70 pertenciam ao sexo masculino (66%) e a idade ao diagnóstico variou de dois meses a 22 anos. Os sinais e sintomas de maior frequência foram cefaleia (80,8%) e vômitos (75,8%). Em relação ao tratamento, a maioria (63,2%) dos pacientes foi submetida à ressecção cirúrgica total e apresentava como histologia predominante a forma clássica (63,2%). A taxa de sobrevida global em cinco anos foi de 67,9% e, em 10 anos, de 64,2%. Os pacientes com perfil molecular característico do subgrupo wingless (WNT) apresentaram melhor prognóstico, com sobrevida global em cinco anos de 75%. Conclusões: As características clínicas, demográficas, anatomopatológicas e moleculares dos pacientes com meduloblastoma descritas no presente estudo foram majoritariamente semelhantes às descritas na literatura. Pacientes submetidos à ressecção completa do tumor tiveram melhor evolução clínica do que aqueles com ressecção incompleta/biópsia. Pacientes estratificados como de alto risco apresentaram pior sobrevida global e livre de eventos do que o grupo standard e a presença de metástases ao diagnóstico se mostrou associada à ocorrência de recidiva da doença.

Comparison between qualitative and real-time polymerase chain reaction to evaluate minimal residual disease in children with acute lymphoblastic leukemia

Introduction: Minimal residual disease is an important independent prognostic factor that can identify poor responders among patients with acute lymphoblastic leukemia. Objective: The aim of this study was to analyze minimal residual disease using immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements by conventional polymerase chain reaction followed by homo-heteroduplex analysis and to compare this with real-time polymerase chain reaction at the end of the induction period in children with acute lymphoblastic leukemia. Methods: Seventy-four patients diagnosed with acute lymphoblastic leukemia were enrolled. Minimal residual disease was evaluated by qualitative polymerase chain reaction in 57 and by both tests in 44. The Kaplan-Meier and multivariate Cox methods and the log-rank test were used for statistical analysis. Results: Nine patients (15.8%) were positive for minimal residual disease by qualitative polymerase chain reaction and 11 (25%) by real-time polymerase chain reaction considering a cut-off point of 1 × 10−3 for precursor B-cell acute lymphoblastic leukemia and 1 × 10−2 for T-cell acute lymphoblastic leukemia. Using the qualitative method, the 3.5-year leukemia- free survival was significantly higher in children negative for minimal residual disease compared to those with positive results (84.1% ± 5.6% versus 41.7% ± 17.3%, respectively; p-value = 0.004). There was no significant association between leukemia-free survival and minimal residual disease by real-time polymerase chain reaction. Minimal residual disease by qualitative polymerase chain reaction was the only variable significantly correlated to leukemia-free survival. Conclusion: Given the difficulties in the implementation of minimal residual disease monitoring by real-time polymerase chain reaction in most treatment centers in Brazil, the qualitative polymerase chain reaction strategy may be a cost-effective alternative.