Deregulated FADD expression and phosphorylation in T-cell lymphoblastic lymphoma

// José L. Marín-Rubio 1, 2, 3 , María C. de Arriba 4, 5 , María A. Cobos-Fernández 1, 2 , Laura González-Sánchez 1, 2, 6 , Inmaculada Ors 3 , Isabel Sastre 1 , José Fernández-Piqueras 1, 2, 3, 6 , María Villa-Morales 1, 2, 3, 6 1 Centro de Biología Molecular Severo Ochoa (CBMSO), Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain 2 IIS-Fundación Jiménez Díaz, Madrid, Spain 3 Universidad Autónoma de Madrid, Departamento de Biología, Madrid, Spain 4 Universidad Carlos III, Departamento de Bioingeniería, Madrid, Spain 5 Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain 6 Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), Valencia, Spain Correspondence to: María Villa-Morales, email: mvilla@cbm.csic.es José Fernández-Piqueras, email: jfpiqueras@cbm.csic.es Keywords: T-cell lymphoblastic lymphoma, Fas-associated death domain protein (FADD), expression and phosphorylation, tumor aggressiveness, prognostic marker Received: April 20, 2016 Accepted: August 11, 2016 Published: August 18, 2016 ABSTRACT In the present work, we show that T-cell lymphoblastic lymphoma cells exhibit a reduction of FADD availability in the cytoplasm, which may contribute to impaired apoptosis. In addition, we observe a reduction of FADD phosphorylation that inversely correlates with the proliferation capacity and tumor aggressiveness. The resultant balance between FADD-dependent apoptotic and non-apoptotic abilities may define the outcome of the tumor. Thus, we propose that FADD expression and phosphorylation can be reliable biomarkers with prognostic value for T-LBL stratification.