Multiparametric analysis of HA14-1-induced apoptosis in follicular lymphoma cells

The compounds aimed to directly bind and inhibit Bcl-2 and related anti-apoptotic proteins have entered the clinical or pre-clinical stage of evaluation and represent a promising new strategy to combat cancer. Having reported a pro-apoptotic function of a small molecule inhibitor of Bcl-2, HA14-1, in follicular lymphoma cell lines, we provide herein further insights into the action of this compound in our model. Employing both pharmacological inhibitor studies and multiparametric flow cytometry assays, we demonstrated that following HA14-1 treatment caspase activation occurs solely as a consequence of mitochondrial breach. Moreover, applying bivariate analysis of the DNA content and fluorochrome-labeled inhibitor of caspases (FLICA) binding, we investigated for the first time the cell cycle specificity of HA14-1-evoked apoptosis in FL cells upon different exposure scenarios. Overall, the study provides both mechanistic and clinically relevant information about the action of HA14-1.