Microenvironment-dependent upregulation of Bcl-xL mediates loss of priming. (A) Bcl-xL immunoprecipitation in primary MCL cells (Pt 12) and Maver-1 cells cocultured or not on L-40L+Ck. The lysate (IN), immunoprecipitates (IP), and IP supernatants (OUT) were analyzed by immunoblotting for the indicated proteins. *Highlights different exposure for IP and IN/OUT. (B) Bcl-2 and Bcl-xL immunoprecipitation in Maver-1 cells cocultured or not on L-40L with or without VNT (3 hours, 50 nM) pretreatment. Lower, Quantification of protein level. (C) BH3-profiling of Maver-1 cells cultured as in panel B and performed as described in “Methods.” Values are the mean of 3 independent experiments. (D) Schematic representation of how microenvironment-dependent upregulation of Bcl-xL mediates loss of priming. (E) Maver-1 cells cultured or not on L-40L with or without VNT (50 nM) and Bcl-xL mimetic A1331852 (0.5 µM). Cell death was assessed using annexin-V staining. Values are the mean of 3 independent experiments.
