NTSR2 silencing decreases B-CLL viability and induces apoptosis. (a) Representative western blot of B-CLL lymphocytes transfected with either a non-relevant siRNA (siRNA control, siCo) or a pool of four different siRNAs directed against NTSR2 (siNTSR2). (b) NTSR2 protein level, expressed as fold change vs control (siCo), normalized against actin, in three different B-CLL patients. (c) B-CLL cell viability (n=4), expressed as a percentage, 72 h after NTSR2 depletion (siCo vs SiNTSR2). (d) Representative fluorescence-activated cell sorting analysis of apoptosis induction, assessed by Annexin V-fluorescein Isothiocyanate/PI dual staining of B-CLL cells (n=4) depleted or not for NTSR2. (e) Percentage of apoptotic cells (Annexin V-positive cells) after NTSR2 silencing in B-CLL vs siCo. (f) Apoptotic ratio in B-CLL cells (n=5) 72 h after NTSR2 depletion, assessed by cell death ELISA, expressed as fold change vs control (siCo). (g) Representative western blot analysis of p-Src and Bcl-2 expression from B-CLL cell lysates, depleted of NTSR2 or not for 72 h. (h, i) Histogram bars represent the fold change in phosphorylation level of Src or Bcl-2 expression in siNTSR2 cells, normalized against actin, in comparison with siCo. Significant P-values are indicated in the graphs **P<0.01, ***P<0.001.