Higenamine Enhances the Antitumor Effects of Cucurbitacin B in Breast Cancer by Inhibiting the Interaction of AKT and CDK2.

Cucurbitacin B (Cu B), a tetracyclic triterpenoid derived from Trichosanthes kirilowii Maxim, exhibits anticancer effects against various types of tumor. Higenamine, isolated from Radix Aconiti Lateralis Preparata, has been used as a dietary supplement for regulating metabolic function. The present study suggested that higenamine enhances Cu B-induced cytotoxicity in breast cancer cells and in vivo. Network pharmacology analysis was used to identify the possible mechanism of action. Cu B alone inhibited breast cancer cell growth, induced apoptosis, and arrested the cell cycle in the G2/M phase. Cu B combined with higenamine potentiated the cytotoxic effect of Cu B, resulting in the enhanced induction of apoptosis and G2/M arrest. The network pharmacology analysis also found that the major predicted targets of Cu B in breast cancer were AKT, endoplasmic reticulum, farnesyltransferase, CAAX box, alpha, platelet-derived growth factor receptor alpha, peroxisome proliferator-activated receptor, RET proto-oncogene, and vascular endothelial growth factor A. The possible targets of higenamine involved in the synergic action were cyclin A2, cyclin-dependent kinase 2 (CDK2), dihydrofolate reductase, and protein kinase CAMP-activated catalytic subunit alpha. The associated pathways were summarized by Kyoto Encyclopedia of Genes and Genomes pathway analysis, and it was hypothesized that higenamine may enhance the antitumor effects of Cu B in breast cancer through inhibition of the interaction of AKT and CDK2. The protein expression was assayed by western blot analysis. The combined treatment also resulted in significant inhibition of growth in vivo.