Figure 1.
Combination therapy with EZH2 and Bcl-2 inhibitors has in vitro antitumor activity in DLBCL model systems. (A) Cell viability, as measured by CellTiter-Glo, in a panel of DLBCL cell lines treated with vehicle, venetoclax alone (V), tazemetostat alone (T), or venetoclax and tazemetostat in combination (C). Drug dosing for each cell line was optimized to approximate 50% killing (supplemental Table 2). Results represent the mean of 3 biologic replicates, each of which was performed in experimental triplicates. Error bars represent standard error of the mean (SEM). (B) Confidence interval value for DLBCL cells treated with vehicle, venetoclax alone, tazemetostat alone, or venetoclax and tazemetostat in combination over a range of doses at fixed ratios (supplemental Table 3). Cell viability was measured using CellTiter-Glo. Synergy was calculated using CompuSyn. Results represent the mean of 3 biologic replicates, each of which was performed in experimental triplicates. Error bars represent SEM. (C-D) Immunofluorescence of DLBCL organoids treated with vehicle, 50 nM venetoclax, 5 μM tazemetostat, or venetoclax and tazemetostat in combination. Live and dead cells were identified by calcein-AM and ethidium homodimer, respectively, on day 8. Image were obtained on a Nikon TE200U microscope. (E) Percentage of live OCI-Ly1 cells by flow cytometry. Cells were stained for live and dead populations using a LIVE/DEAD Fixable Far Red Dead Cell Stain Kit (Thermo Fisher Scientific; cat. no. L34974). (F) Heat map showing RNA sequencing log2 fold change in BCL2 family members in DLBCL cell lines treated with vehicle vs tazemetostat. The Wilcoxon test was used to determine statistical significance. (G) BH3 profiling of DLBCL PDX cells treated with tazemetostat or vehicle. BIM and PUMA evaluate general priming, BAD evaluates Bcl-2–specific priming, MS1 evaluates MCL-1 priming, and HRK evaluates BCL-XL priming. Error bars represent SEM. *P < .05, **P < .01, ***P < .001, ****P < .0001. Com, combination; ns, not significant; Taz, tazemetostat; Veh, vehicle; Ven, venetoclax.

Combination therapy with EZH2 and Bcl-2 inhibitors has in vitro antitumor activity in DLBCL model systems. (A) Cell viability, as measured by CellTiter-Glo, in a panel of DLBCL cell lines treated with vehicle, venetoclax alone (V), tazemetostat alone (T), or venetoclax and tazemetostat in combination (C). Drug dosing for each cell line was optimized to approximate 50% killing (supplemental Table 2). Results represent the mean of 3 biologic replicates, each of which was performed in experimental triplicates. Error bars represent standard error of the mean (SEM). (B) Confidence interval value for DLBCL cells treated with vehicle, venetoclax alone, tazemetostat alone, or venetoclax and tazemetostat in combination over a range of doses at fixed ratios (supplemental Table 3). Cell viability was measured using CellTiter-Glo. Synergy was calculated using CompuSyn. Results represent the mean of 3 biologic replicates, each of which was performed in experimental triplicates. Error bars represent SEM. (C-D) Immunofluorescence of DLBCL organoids treated with vehicle, 50 nM venetoclax, 5 μM tazemetostat, or venetoclax and tazemetostat in combination. Live and dead cells were identified by calcein-AM and ethidium homodimer, respectively, on day 8. Image were obtained on a Nikon TE200U microscope. (E) Percentage of live OCI-Ly1 cells by flow cytometry. Cells were stained for live and dead populations using a LIVE/DEAD Fixable Far Red Dead Cell Stain Kit (Thermo Fisher Scientific; cat. no. L34974). (F) Heat map showing RNA sequencing log2 fold change in BCL2 family members in DLBCL cell lines treated with vehicle vs tazemetostat. The Wilcoxon test was used to determine statistical significance. (G) BH3 profiling of DLBCL PDX cells treated with tazemetostat or vehicle. BIM and PUMA evaluate general priming, BAD evaluates Bcl-2–specific priming, MS1 evaluates MCL-1 priming, and HRK evaluates BCL-XL priming. Error bars represent SEM. *P < .05, **P < .01, ***P < .001, ****P < .0001. Com, combination; ns, not significant; Taz, tazemetostat; Veh, vehicle; Ven, venetoclax.

Close Modal
This Feature Is Available To Subscribers Only

or Create an Account

Close Modal
Close Modal