Figure 6.

ETV6 silencing has an important cytotoxic effect in aggressive B-cell lymphoma cell lines. (A,B) Representative plots of apoptosis (A) and quantification of apoptosis (B) in RIVA and OCI-Ly3 ABC-type cells (top and bottom or left and right, respectively) transduced with shCTRL, shETV6#1 and shETV6#2 shortly after puromycin selection and maintained for 48 h in regular culture medium (20% FCS). In (B), data are represented as Mean ± SD of two independent experiments. For statistical analysis, an unpaired t-test was used. (C) Western blot evaluating the expression levels of cleaved PARP-1, XIAP and Survivin/BIRC5 in OCI-Ly3 and RIVA cells transduced with shCTRL, shETV6#1 and shETV6#2. β-actin was used as loading control. Relative protein expressions (normalized to loading control) are shown on top of appropriate panels. (D) Evaluation of ETV6 and BIRC5 protein expression levels in DLBCL cell lines of different molecular subtypes (ABC and GCB-type) and Burkitt lymphoma (BL) cell lines using immunoblotting. Tubulin is shown as loading control. The numbers above the blots indicate expression levels relative to the loading control. Genetic subgroups [36] of the cell lines are also shown. EZB = EZH2 mutations and BCL2 translocations, MCD = MYD88 and CD79b mutations. kD = kilodaltons. (E) Linear regression analysis of the relationship between ETV6 and BIRC5 protein levels in B-cell lymphoma cell lines shown in (D). (F) Dot plot showing the inhibitory concentration determining 50% loss of viability (IC50) for the BIRC5 inhibitor YM155 in relation to ETV6 protein expression levels in B-cell lymphoma cell lines (n = 9). For statistical analysis, an unpaired t-test was used.