Abstract
Emerging evidence has suggested that targeting glycolysis may be a promising strategy for cancer treatment. Betulinic acid (BA) is a natural pentacyclic terpene that has been reported to be active in inhibiting various malignancies. Here, we showed that BA could inhibit aerobic glycolysis activity in breast cancer cell lines MCF-7 and MDA-MB-231 by hampering lactate production, glucose uptake and extracellular acidification rate (ECAR), as well as suppressing aerobic glycolysis-related proteins including c-Myc, lactate dehydrogenase A (LDH-A) and p-PDK1/PDK1 (pyruvate dehydrogenase kinase 1). Mechanistic studies validated Caveolin-1 (Cav-1) as one of key targets of BA in suppressing aerobic glycolysis, as BA administration resulted in Cav-1 upregulation, whereas silencing Cav-1 abrogated the inhibitory effect of BA on aerobic glycolysis. Further investigations demonstrated that BA suppressed aerobic glycolysis in breast cancer cells by regulating the Cav-1/NF-κB/c-Myc pathway. More meaningfully, BA significantly inhibited breast cancer growth and glycolytic activity in both the transgenic MMTV-PyVT+/- breast cancer spontaneous model and the zebrafish breast cancer xenotransplantation model without any detectable side effects in vivo. Taken together, our study sheds novel insights into BA as a promising candidate drug for suppressing aerobic glycolysis, highlighting Cav-1 as a potential molecular target of BA and aerobic glycolysis regulation.