Overexpression of the novel member of the BCL2 gene family, BCL2L12, is associated with the disease outcome in patients with acute myeloid leukemia Hellinida Thomadaki a , Konstantinos V. Floros a , Sonja Pavlovic b , Natasa Tosic b , Dimitrios Gourgiotis c , Milica Colovic d , Andreas Scorilas a, ⁎ a Department of Biochemistry and Molecular Biology, University of Athens, Athens, Greece b Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia c Research Laboratories, 2nd Department of Pediatrics, University of Athens, Faculty of Medicine, “P. & A. Kyriakou” Children's Hospital, Athens, Greece d Institute of Hematology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia abstract article info Article history: Received 2 May 2012 Received in revised form 31 May 2012 Accepted 12 June 2012 Available online 19 June 2012 Keywords: AML BCL2 family Apoptosis Real-time PCR Prognosis Objectives: BCL2L12 is a recently discovered and cloned gene from members of our research team. It is a novel member of the BCL2 gene family, members of which are implicated in different hematological malig- nancies. In the present study, we investigated and studied the expression profile of BCL2L12 in acute myeloid leukemia (AML). Design and methods: Total RNA was isolated from peripheral blood of 67 AML patients and healthy do- nors. The expression profile of BCL2L12 was studied using real-time PCR methodology (SYBR Green chemis- try). We also evaluated the association of the BCL2L12 mRNA expression level with clinical and pathological disease parameters, as well with disease-free survival (DFS) and overall survival (OS), using the chi-square (χ 2 ) test or the Fisher's exact test, where appropriate. Results: Leukemia patients expressing high level of BCL2L12 were 3 times more likely to relapse (p = 0.004) or die (p = 0.007) than patients with low level of BCL2L12 expression. Additionally, statistically significant relationships were revealed between BCL2L12 expression level and CD117 expression, the pres- ence of splenomegaly and chemotherapy response. Conclusions: Our results suggest that BCL2L12 can be considered as a new independent prognostic and chemotherapy response marker in AML. © 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved. Introduction Acute myeloid leukemia (AML) encompasses a phenotypically and genetically heterogeneous group of malignant disorders, arising be- cause of uncontrolled proliferation of clonal leukemic progenitor cells, arrested at various stages of myeloid differentiation. The devel- opment of AML is associated with acquired genetic alterations (such as balanced translocations and other cytogenetic abnormalities) and epigenetic changes that alter the normal mechanisms of cell growth, proliferation, differentiation and death. Many of these alterations are used as diagnostic and prognostic markers, as well as markers of minimal residual disease (MRD) status. There is also a variety of clin- ical symptoms for AML, including hepatomegaly, splenomegaly, leu- kemia cutis and lymphadenopathy due to the leukemic penetration of the bone marrow [1]. Another marker of AML is the expression of c-kit (CD117), which is a tyrosine kinase receptor expressed in a va- riety of cell types and which mediates proliferation as well as anti- apoptotic effects [2]. Treatment of AML usually involves an aggressive chemotherapy regimen, which leads to a complete remission rate of ~ 72% and a sur- vival rate of only ~35%. The primary cause of treatment failure in adult AML patients is the emergence of resistant disease. Multiple mechanisms may account for the reason why leukemic cells become resistant to chemotherapy, but the common causes include defects in apoptotic pathways [3]. Recent research approaches support the hypothesis that impair- ment of apoptosis is central to tumorigenesis. Many genes involved in apoptosis, e.g. the BCL2 family members, have been suggested as prognostic biomarkers of cancer, because of their characteristic ex- pression in different types of tumors. It is well known that changes in the expression level of the main regulators of the apoptosis ma- chinery, such as BCL2, BAD and BAX, contribute to poor outcome in pa- tients with AML [4]. BCL2-like 12 (BCL2L12) is a member of the BCL2 family, discovered and cloned by members of our group in 2001. The BCL2L12 gene is lo- cated on chromosome 19q13.3, between the IRF3 and the PRMT1/ Clinical Biochemistry 45 (2012) 1362–1367 ⁎ Corresponding author at: Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Athens, Panepistimiopolis, Athens 15701, Greece. Fax: + 30 2107274158. E-mail address: ascorilas@biol.uoa.gr (A. Scorilas). 0009-9120/$ – see front matter © 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved. doi:10.1016/j.clinbiochem.2012.06.012 Contents lists available at SciVerse ScienceDirect Clinical Biochemistry journal homepage: www.elsevier.com/locate/clinbiochem