[Copy number alterations in adult patients with mature B acute lymphoblastic leukemia treated with specific immunochemotherapy]

Abstract

Background and objective: Unlike Burkitt lymphoma, molecular abnormalities other than C-MYC rearrangements have scarcely been studied in patients with mature B acute lymphoblastic leukemia (B-ALL). The aim of this study was to analyze the frequency and prognostic significance of copy number alterations (CNA) in genes involved in lymphoid differentiation, cell cycle and tumor suppression in adult patients with B-ALL.

Patients and methods: We have analyzed by multiplex ligation-dependent probe amplification the genetic material from bone marrow at diagnosis from 25 adult B-ALL patients treated with rituximab and specific chemotherapy.

Results: The most frequent CNA were alterations in the 14q32.33 region (11 cases, 44%) followed by alterations in the cell cycle regulator genes CDKN2A/B and RB1 (16%). No correlation between the presence of specific CNA and the clinical-biologic features or the response to therapy was found.

Conclusions: The high frequency of CNA in the 14q32.33 region, CDKN2A/B and RB1 found in our study could contribute to the aggressiveness and invasiveness of mature B-ALL.

Keywords: 14q32.33 region; Alteraciones del número de copias; Amplificación de sondas dependiente de ligamento múltiple; Copy number alterations; Leucemia linfoblástica B madura; Mature B-leukemia; Multiplex ligation-dependent probe amplification; Región 14q32.33.