BCL2L12 improves risk stratification and prediction of BFM-chemotherapy response in childhood acute lymphoblastic leukemia.

Background Risk-adjusted treatment has led to outstanding improvements of the remission and survival rates of childhood acute lymphoblastic leukemia (ALL). Nevertheless, overtreatment-related toxicity and resistance to therapy have not been fully prevented. In the present study, we evaluated for the first time the clinical impact of the apoptosis-related BCL2L12 gene in prognosis and risk stratification of BFM-treated childhood ALL. Methods Bone marrow specimens were obtained from childhood ALL patients upon disease diagnosis and the end-of-induction (EoI; day 33) of the BFM protocol, as well as from control children. Following total RNA extraction and reverse transcription, BCL2L12 expression levels were determined by qPCR. Patients' cytogenetics, immunophenotyping and minimal residual disease (MRD) evaluation were performed according to the international guidelines. Results BCL2L12 expression was significantly increased in childhood ALL and correlated with higher BCL2/BAX expression ratio and favorable disease markers. More importantly, BCL2L12 expression was associated with disease remission, while the reduced BCL2L12 expression was able to predict patients' poor response to BFM therapy, in terms of M2-M3 response and MRD≥0.1% on day 15. The survival analysis confirmed the significantly higher risk of the BFM-treated patients underexpressing BCL2L12 at disease diagnosis for early relapse and worse survival. Lastly, evaluation of BCL2L12 expression clearly strengthened the prognostic value of the established disease prognostic markers, leading to superior prediction of patients' outcome and improved specificity of BFM risk stratification. Conclusions The expression levels of the apoptosis-related BCL2L12 predict response to treatment and survival outcome of childhood ALL patients receiving BFM chemotherapy.

Clinical utility of miR-143/miR-182 levels in prognosis and risk stratification specificity of BFM-treated childhood acute lymphoblastic leukemia.

Although childhood acute lymphoblastic leukemia (ALL) is characterized by high remission rates, there are still patients who experience poor response to therapy or toxic effects due to intensive treatment. In the present study, we examined the expression profile of miR-143 and miR-182 in childhood ALL and evaluated their clinical significance for patients receiving Berlin-Frankfurt-Münster (BFM) protocol. Bone marrow specimens from 125 childhood ALL patients upon diagnosis and the end-of-induction (EoI; day 33), as well as from 64 healthy control children undergone RNA extraction, polyadenylation, and reverse transcription. Expression levels of miRNAs were quantified by qPCR analysis. Patients' cytogenetic, immunohistotype and MRD evaluation was performed according to international guidelines. Median follow-up time was 86.0 months (95% CI 74.0-98.0), while patients' mean DFS and OS intervals were 112.0 months (95% CI 104.2-119.8) and 109.2 months (95% CI 101.2-117.3), respectively. Bone marrow levels of miR-143/miR-182 were significantly decreased in childhood ALL patients at diagnosis and increased in more than 90% of patients at the EoI. Patients' survival analysis highlighted that children overexpressing miR-143/miR-182 at the EoI presented significantly higher risk for short-term relapse (log-rank test: p = 0.021; Cox regression: HR = 4.911, p = 0.038) and death (log-rank test: p = 0.028; Cox regression: HR = 4.590, p = 0.046). Finally, the evaluation of the miR-143/miR-182 EoI levels along with the established disease prognostic markers resulted to improved prediction of BFM-treated patients' survival outcome and response to therapy and additionally to superior BFM risk stratification specificity. Concluding, miR-143 and miR-182 could serve as novel prognostic molecular markers for pediatric ALL treated with BFM chemotherapy.

miR-125b predicts childhood acute lymphoblastic leukaemia poor response to BFM chemotherapy treatment.

BACKGROUND: Despite the favourable survival rates of childhood acute lymphoblastic leukaemia (ALL), a significant number of patients present resistance to antileukaemic agents and dismal prognosis. In this study, we analysed miR-125b expression in childhood ALL and evaluated its clinical utility for patients treated with Berlin-Frankfurt-Münster (BFM) protocol. METHODS: The study included 272 bone marrow specimens obtained on diagnosis and on BFM day 33 from 125 patients and 64 healthy children. Following extraction, RNA was polyadenylated and reverse transcribed. miR-125b levels were quantified by quantitative PCR. Cytogenetics, immunohistotype and MRD were analysed according to international guidelines. RESULTS: Downregulated miR-125b levels were detected in childhood ALL patients and correlated with adverse prognosis. Following BFM induction, miR-125b levels were significantly increased, however, elevated day 33/diagnosis miR-125b ratio was associated with unfavourable disease features. Loss of miR-125b during diagnosis and higher day 33/diagnosis ratio were correlated with stronger risk for disease short-term relapse and patients' worse survival. Moreover, multivariate regression models highlighted the independent prognostic value of miR-125b for childhood ALL. Finally, the combination of miR-125b with clinically used disease markers clearly enhanced the prediction of patients' resistance to BFM chemotherapy. CONCLUSIONS: miR-125b significantly improves the prognosis of childhood ALL patients' outcome under BFM treatment.

Overexpression of BCL2 and BAX following BFM induction therapy predicts ch-ALL patients' poor response to treatment and short-term relapse.

PURPOSE: The identification of childhood acute lymphoblastic leukemia (ch-ALL) patients who are at a higher risk of chemotherapy resistance and relapse is essential for successful treatment decisions, despite the application of novel therapies. The aim of the study is the evaluation of BCL2 and BAX expression for the prognosis of ch-ALL patients treated with Berlin-Frankfurt-Münster (BFM) backbone protocol. METHODS: Bone marrow specimens were obtained at the time of diagnosis and on day 33 following BFM treatment induction from 82 ch-ALL patients, as well as from 63 healthy children. Following extraction, total RNA was reverse transcribed and BCL2 and BAX expression levels were determined by qPCR. RESULTS: BCL2 expression and BCL2/BAX ratio were strongly upregulated in ch-ALL compared to healthy children and were correlated with favorable prognostic disease features. Increased levels of BCL2 and BAX expression were associated with disease remission, as ch-ALL patients with lower expression ran a significantly higher risk of M2-M3 response, positive MRD and poor survival outcome. Moreover, the upregulation of BCL2 and BAX following BFM treatment induction was shown to represent an independent predictor of patients' short-term relapse, which was further confirmed in ch-ALL patients with favorable prognostic markers. CONCLUSIONS: In conclusion, BCL2 and BAX could be effectively used for an enhanced prediction of BFM-treated patients' outcome.