Uncovering Anticancer Mechanisms of Spiramycin Derivatives Using Transcriptomic and Metabolomic Analyses

Background: Carrimycin is a mixture of spiramycin derivatives with antibacterial functions. However, recent studies have shown that it possesses certain anticancer properties. The specific mechanism of the anticancer activity is unknown. Methods: To study the anticancer mechanism of carrimycin, we synthesized a derivative of spiramycin, n-hexyl spiramycin (h-SPM), and used a combination of metabolomics and transcriptomics methods. Capillary electrophoresis-mass spectrometry (CE-MS) was used to detect polar small molecule metabolites, and liquid chromatography-mass spectrometry (LC-MS) was used to detect lipid metabolites in cells. Transcriptomics was used to measure mRNA content in cells. Finally, by processing these data using specific bioinformatics methods, the mechanism underlying anticancer effect of carrimycin was determined. Results: Metabolomics and transcriptomic results showed that lipid metabolism and mitochondrial biogenesis pathways in the cells changed after hSPM treatment, NR1D1 genes and ceramide were enriched from these pathways, implicating the involvement of ROS and pro-inflammatory response. Western blotting verified that the protein levels of NR1D1 decreased after h-SPM treatment, and ROS stating and qPCR demonstrated that ROS levels and the mRNA levels of pro-inflammatory genes were greatly induced by h-SPM. Conclusions: h-SPM reduced the protein level of NR1D1, disrupted metabolic regulation, accumulating ceramide, and the subsequent increased ROS generation promoted apoptosis and pro-inflammatory-like response of cells. Our findings unveiled the anticancer mechanism of a potent anticancer derivative of spiramycin and unveiled its mechanism of action.