Abstract 1463 The discovery of botanical extracts with selective TNBC activity

Among women, breast cancer is the most common type of cancer and second leading cause of cancer-related death. Triple-negative breast cancer (TNBC) is a type of breast cancer that does not express the estrogen, progesterone, and HER2 receptors which are pathologically used to classify breast cancers. Because TNBC lacks these 3 receptors, chemotherapy is the only main systemic treatment option for these patients. This limitation in treatment options places TNBC at a high-risk of relapse, short progression-free survival, and lower overall survival. Due to the molecular heterogeneity of TNBC which stratifies the disease into 4 distinct subtypes (BL1, BL2, LAR and M), the development of a single effective therapy has been challenging. Considering that many current anti-cancer therapeutic agents like Paclitaxel and Vincristine originate from natural sources, natural product from botanical extracts found in the San Antonio, TX area will be a rich source to identify drug leads that will selectively target a distinct subtype of TNBC. This was done by collecting and identifying plant samples, lyophilizing them and preparing methanolic extracts by Soxhlet extraction. These samples were placed in a 96-well plate and tested for selective anti-TNBC activity using the colorimetric SRB assay. Among these, the extract of Euphorbia milii displayed robust selective cytotoxicity against cells belonging to the basal like 2 (BL2) subtype of TNBC. The findings from this study will assist in the identification of components from natural products with potential selective TNBC activity conducive to the development of improved treatments against the disease. Additionally, the identified compounds will inform on druggable oncogenic pathways in TNBC. This material is based upon work supported by the National Science Foundation under Grant No. (NSF 1741933). This project was also supported by the Welch Foundation (BN-0032) and the Department of Chemistry and Biochemistry at the University of the Incarnate Word.