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Synergistic Anti-Tumor Activity of EZH2 Inhibitors and Glucocorticoid Receptor Agonists in Models of Germinal Center Non-Hodgkin Lymphomas.

Knutson SK, Warholic NM, Johnston LD, Klaus CR, Wigle TJ, Iwanowicz D, Littlefield BA, Porter-Scott M, Smith JJ, Moyer MP, Copeland RA, Pollock RM, Kuntz KW, Raimondi A, Keilhack H - PLoS ONE (2014)

Bottom Line: Dramatic synergy was observed when EPZ-6438 is combined with Prednisolone alone, and a similar effect was observed with Dexamethasone, another GRag.Remarkably, the anti-proliferative effect of the EPZ-6438+GRag combination extends beyond EZH2 mutant-bearing cells to more generally impact germinal center NHL.The data also suggest the possibility of a significant and practical benefit of combining EZH2 inhibitors and GRag that warrants further investigation in a clinical setting.

View Article: PubMed Central - PubMed

Affiliation: Research and Development, Epizyme Inc., Cambridge, Massachusetts, United States of America.

ABSTRACT
Patients with non-Hodgkin lymphoma (NHL) are treated today with a cocktail of drugs referred to as CHOP (Cyclophosphamide, Hydroxyldaunorubicin, Oncovin, and Prednisone). Subsets of patients with NHL of germinal center origin bear oncogenic mutations in the EZH2 histone methyltransferase. Clinical testing of the EZH2 inhibitor EPZ-6438 has recently begun in patients. We report here that combining EPZ-6438 with CHOP in preclinical cell culture and mouse models results in dramatic synergy for cell killing in EZH2 mutant germinal center NHL cells. Surprisingly, we observe that much of this synergy is due to Prednisolone - a glucocorticoid receptor agonist (GRag) component of CHOP. Dramatic synergy was observed when EPZ-6438 is combined with Prednisolone alone, and a similar effect was observed with Dexamethasone, another GRag. Remarkably, the anti-proliferative effect of the EPZ-6438+GRag combination extends beyond EZH2 mutant-bearing cells to more generally impact germinal center NHL. These preclinical data reveal an unanticipated biological intersection between GR-mediated gene regulation and EZH2-mediated chromatin remodeling. The data also suggest the possibility of a significant and practical benefit of combining EZH2 inhibitors and GRag that warrants further investigation in a clinical setting.

No MeSH data available.


Related in: MedlinePlus

Glucocorticoid agonists enhance potency of EPZ-6438 in EZH2 mutant and wild-type germinal center B cell lymphoma.Combinations of EPZ-6438 with Prednisolone or Dexamethasone in WSU-DLCL2 EZH2 mutant (A, B) and DOHH2 EZH2 wild-type (C, D) GCB lymphoma cell lines, respectively. All dose response plots were generated in Graphpad Prism and curves fitted to a four-parameter model with variable slope (2 biological replicates). Doses of EPZ-6438 ranged from 15.6–1000 nM, doses of Prednisolone ranged from 7.8–1000 nM, and doses of Dexamethasone ranged from 0.8–100 nM. A, B) Potency of EPZ-6438 was increased with Prednisolone or Dexamethasone in EZH2 mutant WSU-DLCL2 cells. C, D) EPZ-6438 showed no anti-proliferative effect as a single agent in DOHH2 EZH2 wild-type cells, therefore the potency shift of Prednisolone or Dexamethasone was measured. The potency of Prednisolone or Dexamethasone was increased with addition of EPZ-6438 in DOHH2 cells.
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pone-0111840-g002: Glucocorticoid agonists enhance potency of EPZ-6438 in EZH2 mutant and wild-type germinal center B cell lymphoma.Combinations of EPZ-6438 with Prednisolone or Dexamethasone in WSU-DLCL2 EZH2 mutant (A, B) and DOHH2 EZH2 wild-type (C, D) GCB lymphoma cell lines, respectively. All dose response plots were generated in Graphpad Prism and curves fitted to a four-parameter model with variable slope (2 biological replicates). Doses of EPZ-6438 ranged from 15.6–1000 nM, doses of Prednisolone ranged from 7.8–1000 nM, and doses of Dexamethasone ranged from 0.8–100 nM. A, B) Potency of EPZ-6438 was increased with Prednisolone or Dexamethasone in EZH2 mutant WSU-DLCL2 cells. C, D) EPZ-6438 showed no anti-proliferative effect as a single agent in DOHH2 EZH2 wild-type cells, therefore the potency shift of Prednisolone or Dexamethasone was measured. The potency of Prednisolone or Dexamethasone was increased with addition of EPZ-6438 in DOHH2 cells.

Mentions: The combination of EPZ-6438+Mafosfamide displayed additivity in both EZH2 mutant cell lines (Fig. 1A, D). In WSU-DLCL2 cells, EPZ-6438+Doxorubicin acted synergistically in the 4+3 model (Fig. 1B), while this combination was additive in SUDHL10 cells (Fig. 1E). The combination of EPZ-6438+Vincristine also demonstrated additivity in both cell lines (Fig. 1C, F). Treatment of WSU-DLCL2 cells with Prednisolone+EPZ-6438 caused an enhancement of EPZ-6438 activity (Fig. 2A), with a maximum 24-fold reduction in EPZ-6438 IC50 (Fig. 3A and S1 File table B). Treatment with a different GRag, Dexamethasone, resulted in an even greater 30-fold reduction in the IC50 of EPZ-6438 (Fig. 2B, 3B and S1 File table B). At biologically relevant concentrations of 1 µM for Prednisolone and 100 nM for Dexamethasone the potency enhancements were 7 and 15-fold, respectively (S1 File table C); enhancement of EPZ-6438 potency was also observed in SUDHL10 and SUDHL6 cells (S1 File figure A, tables B and C).


Synergistic Anti-Tumor Activity of EZH2 Inhibitors and Glucocorticoid Receptor Agonists in Models of Germinal Center Non-Hodgkin Lymphomas.

Knutson SK, Warholic NM, Johnston LD, Klaus CR, Wigle TJ, Iwanowicz D, Littlefield BA, Porter-Scott M, Smith JJ, Moyer MP, Copeland RA, Pollock RM, Kuntz KW, Raimondi A, Keilhack H - PLoS ONE (2014)

Glucocorticoid agonists enhance potency of EPZ-6438 in EZH2 mutant and wild-type germinal center B cell lymphoma.Combinations of EPZ-6438 with Prednisolone or Dexamethasone in WSU-DLCL2 EZH2 mutant (A, B) and DOHH2 EZH2 wild-type (C, D) GCB lymphoma cell lines, respectively. All dose response plots were generated in Graphpad Prism and curves fitted to a four-parameter model with variable slope (2 biological replicates). Doses of EPZ-6438 ranged from 15.6–1000 nM, doses of Prednisolone ranged from 7.8–1000 nM, and doses of Dexamethasone ranged from 0.8–100 nM. A, B) Potency of EPZ-6438 was increased with Prednisolone or Dexamethasone in EZH2 mutant WSU-DLCL2 cells. C, D) EPZ-6438 showed no anti-proliferative effect as a single agent in DOHH2 EZH2 wild-type cells, therefore the potency shift of Prednisolone or Dexamethasone was measured. The potency of Prednisolone or Dexamethasone was increased with addition of EPZ-6438 in DOHH2 cells.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4262195&req=5

pone-0111840-g002: Glucocorticoid agonists enhance potency of EPZ-6438 in EZH2 mutant and wild-type germinal center B cell lymphoma.Combinations of EPZ-6438 with Prednisolone or Dexamethasone in WSU-DLCL2 EZH2 mutant (A, B) and DOHH2 EZH2 wild-type (C, D) GCB lymphoma cell lines, respectively. All dose response plots were generated in Graphpad Prism and curves fitted to a four-parameter model with variable slope (2 biological replicates). Doses of EPZ-6438 ranged from 15.6–1000 nM, doses of Prednisolone ranged from 7.8–1000 nM, and doses of Dexamethasone ranged from 0.8–100 nM. A, B) Potency of EPZ-6438 was increased with Prednisolone or Dexamethasone in EZH2 mutant WSU-DLCL2 cells. C, D) EPZ-6438 showed no anti-proliferative effect as a single agent in DOHH2 EZH2 wild-type cells, therefore the potency shift of Prednisolone or Dexamethasone was measured. The potency of Prednisolone or Dexamethasone was increased with addition of EPZ-6438 in DOHH2 cells.
Mentions: The combination of EPZ-6438+Mafosfamide displayed additivity in both EZH2 mutant cell lines (Fig. 1A, D). In WSU-DLCL2 cells, EPZ-6438+Doxorubicin acted synergistically in the 4+3 model (Fig. 1B), while this combination was additive in SUDHL10 cells (Fig. 1E). The combination of EPZ-6438+Vincristine also demonstrated additivity in both cell lines (Fig. 1C, F). Treatment of WSU-DLCL2 cells with Prednisolone+EPZ-6438 caused an enhancement of EPZ-6438 activity (Fig. 2A), with a maximum 24-fold reduction in EPZ-6438 IC50 (Fig. 3A and S1 File table B). Treatment with a different GRag, Dexamethasone, resulted in an even greater 30-fold reduction in the IC50 of EPZ-6438 (Fig. 2B, 3B and S1 File table B). At biologically relevant concentrations of 1 µM for Prednisolone and 100 nM for Dexamethasone the potency enhancements were 7 and 15-fold, respectively (S1 File table C); enhancement of EPZ-6438 potency was also observed in SUDHL10 and SUDHL6 cells (S1 File figure A, tables B and C).

Bottom Line: Dramatic synergy was observed when EPZ-6438 is combined with Prednisolone alone, and a similar effect was observed with Dexamethasone, another GRag.Remarkably, the anti-proliferative effect of the EPZ-6438+GRag combination extends beyond EZH2 mutant-bearing cells to more generally impact germinal center NHL.The data also suggest the possibility of a significant and practical benefit of combining EZH2 inhibitors and GRag that warrants further investigation in a clinical setting.

View Article: PubMed Central - PubMed

Affiliation: Research and Development, Epizyme Inc., Cambridge, Massachusetts, United States of America.

ABSTRACT
Patients with non-Hodgkin lymphoma (NHL) are treated today with a cocktail of drugs referred to as CHOP (Cyclophosphamide, Hydroxyldaunorubicin, Oncovin, and Prednisone). Subsets of patients with NHL of germinal center origin bear oncogenic mutations in the EZH2 histone methyltransferase. Clinical testing of the EZH2 inhibitor EPZ-6438 has recently begun in patients. We report here that combining EPZ-6438 with CHOP in preclinical cell culture and mouse models results in dramatic synergy for cell killing in EZH2 mutant germinal center NHL cells. Surprisingly, we observe that much of this synergy is due to Prednisolone - a glucocorticoid receptor agonist (GRag) component of CHOP. Dramatic synergy was observed when EPZ-6438 is combined with Prednisolone alone, and a similar effect was observed with Dexamethasone, another GRag. Remarkably, the anti-proliferative effect of the EPZ-6438+GRag combination extends beyond EZH2 mutant-bearing cells to more generally impact germinal center NHL. These preclinical data reveal an unanticipated biological intersection between GR-mediated gene regulation and EZH2-mediated chromatin remodeling. The data also suggest the possibility of a significant and practical benefit of combining EZH2 inhibitors and GRag that warrants further investigation in a clinical setting.

No MeSH data available.


Related in: MedlinePlus