Abstract 5935: Non-allosteric inhibition of enolase 1 sensitizes triple-negative breast cancer for checkpoint inhibitors

Abstract Background: Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer that commonly returns and spreads. Currently, very few options are available for TNBC treatment. Cancer cells exploit glycolytic machinery for the Warburg effect and aerobic glycolysis. Enolase 1 (ENO1) is the glycolytic enzyme expressed in most tissues, and many cancer cells have higher expression. Apart from the glycolytic role in the cytosol, ENO1 also plays different roles in cancer cells, including as a surface receptor. Method: non-allosteric chemical inhibition was developed and tested in vitro for its efficacy and target validation. Subsequently, in vivo examinations were conducted on emerging small molecules in syngeneic and patient-derived murine models of breast cancer to unveil their anti-tumor efficacy. Results: Our non-allosteric small molecule inhibitor, SU212, binds to ENO1 and restricts its movement within cells. SU212 treatment leads to the accumulation of ENO1 in the nucleus where it restrains the activity of c-Myc. The treatment causes the production of truncated ENO1 called myc promoter-binding protein 1 (MBP-1), which limits the activity of c-Myc. Stand-alone treatment of SU212 restrains the tumor progression and metastasis in orthotopic syngeneic and PDX mouse models. Combining SU212 and Anti-PD1 significantly inhibits tumor growth and metastasis in mouse models. C-Myc is linked to protein transcription that aids immune resistance and tumor evasion of immune surveillance. Suppression of c-Myc activity via SU212 treatment sensitizes the TNBC tumors for anti-PD1 therapy. Conclusions: This study provides compelling preclinical data for further development of SU0212 as an immune therapy sensitizer for the treatment of TNBC. Citation Format: Dhanir Tailor, Fernando Jose Garcia-Marques, Abel Bermudez, Wenqi Li, Arpit Dheeraj, Sharon J. Pitteri, Sanjay V. Malhotra. Non-allosteric inhibition of enolase 1 sensitizes triple-negative breast cancer for checkpoint inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5935.