Clin Chem Lab Med 2018; aop Margaritis Avgeris, Lamprini Stamati, Christos K. Kontos, Despina Piatopoulou, Antonios Marmarinos, Marieta Xagorari, Margarita Baka, Dimitrios Doganis, Theodora Anastasiou, Helen Kosmidis, Dimitrios Gourgiotis and Andreas Scorilas* BCL2L12 improves risk stratification and prediction of BFM-chemotherapy response in childhood acute lymphoblastic leukemia https://doi.org/10.1515/cclm-2018-0507 Received January 22, 2018; accepted June 7, 2018 Abstract Background: Risk-adjusted treatment has led to outstand- ing improvements of the remission and survival rates of childhood acute lymphoblastic leukemia (ALL). Never- theless, 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 extrac- tion and reverse transcription, BCL2L12 expression levels were determined by qPCR. Patients’ cytogenetics, immu- nophenotyping 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 expres- sion 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 predic- tion of patients’ outcome and improved specificity of BFM risk stratification. Conclusions: The expression levels of the apoptosis- related BCL2L12 predict response to treatment and sur- vival outcome of childhood ALL patients receiving BFM chemotherapy. Keywords: apoptosis; BCL2; BCL2-like 12; Berlin-Frank- furt-Münster; biomarker; cancer marker; childhood ALL; hematological cancer; pediatric cancer; tumor marker. Introduction Acute lymphoblastic leukemia (ALL) represents the most frequently diagnosed childhood malignancy, responsi- ble for approximately 75% of pediatric leukemias and 25% of all pediatric cancers, worldwide [1]. Treatment advances over the past decades have led to considerable improvements of patients’ remission and survival rates, now approaching 80% and 90% in Western populations, respectively [2, 3]. Chemotherapy protocols based on the original Ber- lin-Frankfurt-Münster (BFM) backbone protocol are fre- quently administered for disease management. Patients’ risk stratification represents the “gold-standard” approach for the adjustment of treatment intensity and prediction *Corresponding author: Prof. Andreas Scorilas, Department of Biochemistry and Molecular Biology, Faculty of Biology, National and Kapodistrian University of Athens, 157 01 Panepistimiopolis, Athens, Greece, Phone: +30-210-727-4306, Fax: +30-210-727-4158, E-mail: ascorilas@biol.uoa.gr. http://orcid.org/0000-0003-2427-4949 Margaritis Avgeris and Christos K. Kontos: Department of Biochemistry and Molecular Biology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece. http://orcid. org/0000-0002-9935-8461 (C.K. Kontos) Lamprini Stamati, Despina Piatopoulou, Antonios Marmarinos, Marieta Xagorari and Dimitrios Gourgiotis: Laboratory of Clinical Biochemistry – Molecular Diagnostics, Second Department of Pediatrics, National and Kapodistrian University of Athens, Medical School, “P. & A. Kyriakou” Children’s Hospital, Athens, Greece Margarita Baka, Dimitrios Doganis and Helen Kosmidis: Department of Pediatric Oncology, “P. & A. Kyriakou” Children’s Hospital, Athens, Greece Theodora Anastasiou: Laboratory of Hematology, “P. & A. Kyriakou” Children’s Hospital, Athens, Greece Brought to you by | University of Sussex Library Authenticated Download Date | 7/18/18 9:04 PM