Unveiling the mechanism of action of nature-inspired anti-cancer compounds using a multi-omics approach.

The 2020 global cancer registry has ranked breast cancer (BCa) as the most commonly diagnosed type of cancer and the most common cause of cancer-related deaths in women worldwide. Increasing resistance and significant side effects continue to limit the efficacy of anti-BCa drugs, hence the need to identify new drug targets and to develop novel compounds to overcome these limitations. Nature-inspired anti-cancer compounds are becoming increasingly popular since they often provide a relatively safe and effective alternative. In this study, we employed multi-omics techniques to gain insights into the relevant mechanism of action of two recently identified new nature-inspired anti-cancer compounds (SIMR3066 and SIMR3058). Discovery proteomics analysis combined with LC-MS/MS-based untargeted metabolomics analysis was performed on compound-treated vs DMSO-treated (control) MCF-7 cells. Downstream protein functional enrichment analysis showed that most of the responsive proteins were functionally associated with antigen processing and neutrophil degranulation, RNA catabolism and protein folding as well as cytoplasmic vesicle lumen and mitochondrial matrix formation. Consistent with the proteomics findings, metabolomic pathway analysis suggested that the differentially abundant compounds indicated altered metabolic pathways such as glycolysis, the Krebs cycle and oxidative phosphorylation. Furthermore, metabolomics-based enriched-for-action pathway analysis showed that the two compounds associate with mercaptopurine, thioguanine and azathioprine related pathways. Lastly, integrated proteomics and metabolomics analysis revealed that treatment of BCa with SIMR3066 disrupts several signaling pathways including p53-mediated apoptosis and the circadian entertainment pathway. Overall, the multi-omics approach we used in this study indicated that it is a powerful tool in probing the mechanism of action of lead drug candidates. SIGNIFICANCE: In this study we adopted a multi-omics (proteomics and metabolomics) strategy to learn more about the molecular mechanisms of action of nature-inspired potential anticancer drugs. Following treatment with SIMR3066 or SIMR3058, the integration of these multi-omics data sets revealed which biological pathways are altered in BCa cells. This study demonstrates that combining proteomics with metabolomics is a powerful method to investigate the mechanism of action of potential anticancer lead drug candidates.