Abstract 2329: ONC212-induced impairment of oxidative phosphorylation is synergistic with glycolysis inhibition in treatment of pancreatic cancer in vitro and in vivo

Abstract

Abstract ONC212 is a fluorinated imipridone shown to have preclinical efficacy against multiple cancers, including pancreatic cancer. One of the binding targets of ONC212 is the mitochondrial peptidase, ClpP, but its role in the anticancer activity of ONC212 is incompletely understood. Understanding the effects of ONC212 on the bioenergetics of pancreatic cancer could facilitate understanding and amplification of its anti-tumor effects. On extracellular flux analysis, ONC212 impairs mitochondrial ATP production and oxidative phosphorylation in multiple pancreatic cancer lines. However, pancreatic adenocarcinoma uses both glycolysis and mitochondrial function to meet its energy demands. Some pancreatic cancer cell lines are resistant to ONC212 inhibition of oxidative phosphorylation alone, but co-treatment with glycolytic inhibitor 2-deoxy-D-glucose (2-DG) synergizes with ONC212 and increases tumor cell death in vitro. Suppression of ClpX, the regulatory binding protein of ClpP, occurs with ONC212 treatment and was used as a biomarker of ONC212 activity. This suppression was demonstrated in multiple pancreatic cancer lines in vitro and in vivo. In a xenograft mouse tumor model of pancreatic cancer using both the ONC212 resistant Bxpc3 pancreatic cancer cell line and the more sensitive HPAF-II cell line, the combination of ONC212 and 2-DG treatment significantly decreased tumor growth and reduced the intertumoral variability. Immunohistochemistry also revealed increased apoptotic markers in these tumors. There was no significant toxicity from dual treatment in mice, which suggests that tumor energy deprivation from dual inhibition of oxidative phosphorylation and glycolysis via ONC212 and 2-DG has a therapeutic window and should be explored further as a potential combination therapy. In addition, if this effect holds true across other models and cancer types, baseline mitoATP percentage could be used as a functional biomarker of sensitivity to ONC212. Citation Format: Anna Donovan Louie, Isacco Ferrarini, Lanlan Zhou, Wafik S. El-Deiry. ONC212-induced impairment of oxidative phosphorylation is synergistic with glycolysis inhibition in treatment of pancreatic cancer in vitro and in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2329.