Abstract
Background and Purpose
Colorectal cancer is the third most common cancer worldwide. HER2 and HER3 are two members of human epidermal receptor family of tyrosine kinase receptors (RTKs) and associated with poor survival in colorectal cancer. They have been observed as important therapeutic targets in various types of cancer. Corosolic acid, a natural pentacyclic triterpene, has been demonstrated to have a significant anti‐cancer activity. However, the target of corosolic acid has not yet been explored. This study aimed to reveal the direct targets of corosolic acid underlying its anti‐cancer activities.
Experimental Approach
The targets of corosolic acid were revealed by the phospho‐RTK array, bio‐layer interferometry, co‐immunoprecipitation, and proximity ligation assay. The inhibitory action of corosolic acid on HER2/HER3 heterodimerization and related downstream signalling were investigated in HCT116 and SW480 cells. In addition, the chemo‐preventive effects of corosolic acid were validated in both HCT116 xenograft model and AOM/DSS model.
Key Results
Our results demonstrated that corosolic acid could prevent NRG1‐induced HER2/HER3 heterodimerization and suppress the phosphorylation of both HER2 and HER3. Furthermore, HER2 and HER3 could regulate the downstream signalling pathways of RalA/RalBP1/CDK1 and PI3K/Akt/PKA, respectively, resulting in the changes in phosphorylation of Drp1 and mitochondrial dynamics. corosolic acid exhibited anti‐cancer activity in both HCT116 xenograft model and AOM/DSS model.
Conclusions and Implications
Collectively, our results demonstrated corosolic acid directly targeted HER2 and HER3 heterodimerization and inhibited mitochondrial fission via regulating RalA/RalBP1/CDK1 and PI3K/Akt/PKA pathways, revealing a novel mechanism underlying the beneficial effects of corosolic acid on colorectal cancer.
… Eagle Medium (KeyGen, Nanjing, China) with 10% fetal bovine serum (FBS, cell science, Germany). CRA was purchased from Chengdu Biopurify Phytochemicals Ltd (Chengdu, China). Mdivi-1 and azoxymethane (AOM) were obtained from Sigma-Aldrich (St Louis …
