Rational design of a BCL6 peptide inhibitor. The figure shows the structure, average GI50, and dose frequency (ie, the number of doses given over a 48-hour period) for successive versions of BPI. GI50 for the different peptides is an average of those obtained in the OCI-Ly1, OCI-Ly7, and OCI-Ly10 DLBCL cell lines. Each peptide and its respective control were tested at multiple doses and frequencies, with the goal of reaching the same potency as recombinant BPI with a single dose administration. The S3 and S6.2 (RI-BPI) peptides (shown in bold) were selected for further studies for the rest of the experiments shown in this article. GI50 indicates growth inhibitory concentration 50%; DF, dose frequency during a 48-hour interval; R, recombinant; S, synthetic; NA, not applicable; light-gray background, L peptides; white background, L-D hybrid peptides; and dark-gray background, D peptides.
