Abstract 5945: Exploring the antiproliferative potential of KHS101 on triple negative breast cancer cell lines

Abstract Breast cancer is the second leading cause of cancer deaths in the world. Among its subtypes, triple-negative breast cancer (TNBC) is highly aggressive, particularly affecting African American (AA) women, with limited treatment choices. HSP60 protein promotes tumorigenesis and is being studied as a possible biomarker to treat cancers such as TNBC. The small molecule KHS101 specifically binds and inhibits the mitochondrial chaperone HSP60. In this study, we hypothesized that KHS101 would inhibit the proliferation of TNBC cells and therefore may have a therapeutic potential. We studied the antiproliferative effects of KHS101 on TNBC cell lines (MDA-MB-231, MDA-MB-468, HCC1806) through MTT cell proliferation and colony forming assays at varying doses and time points (24, 48, 72, and 96 hours). We performed cell cycle analysis to understand the cell cycle response and apoptotic events in treated or control cells. Additionally, the gene expression and frequently altered pathways resulting from KHS101 treatment were analyzed by RNA sequencing of cells treated with vehicle (DMSO) or with various concentrations of KHS101 (1, 2. 5, 5, and 7. 5 uM) for 72 hours. We analyzed the data using GraphPad Prism and Microsoft Excel, with statistical significance set at p ≤ 0. 05. TNBC cell lines exhibited significant dose-response and antiproliferative effects with increased KHS101 doses and treatment durations. Notably, AA breast cancer cells (MDA-MB-468) displayed heightened cytotoxicity and reduced proliferation compared to Caucasian American (CA) breast cancer cells (MDA-MB-231 and HCC1806). Cell cycle analysis revealed G2/M phase arrest, consistent with RNA sequencing data showing downregulation of the activation of ATM/ATR response in KHS101-treated cell lines compared to the controls. Gene set enrichment analysis indicated downregulation of the cell cycle control genes in MDA-MB-231 cells after 72 hours of KHS101 treatment (7. 5 µM). Reactome pathway analysis in KHS101-treated MDA-MB-231 cells showed upregulation of IFN-gamma signaling and degradation of extracellular matrix. Similarly, Kegg pathway analysis showed upregulation in cell adhesion molecules, cytokine-cytokine receptor interaction, antigen processing and presentation, and Natural Killer cell-mediated cytotoxicity in KHS101-treated cancer cells compared to the controls. KHS101 demonstrates varying cytotoxic effects on TNBC cells, with potential implications for antitumor immune responses. Our findings highlight the distinct susceptibility of AA breast cancer cells and suggest KHS101 as a promising avenue for further research in understanding its mechanism of action and validating therapeutic potential in TNBC. Citation Format: Reshma Gurung, Alehegne W. Yirsaw, Muhammad G. Khodary, Temesgen Samuel, Maninder Sandey, Clayton C. Yates, Deepa Bedi. Exploring the antiproliferative potential of KHS101 on triple negative breast cancer cell lines 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 (6Suppl): Abstract nr 5945.