Exploration of atractylenolide III targeting MDM2/p53 axis in breast cancer cell progression based on network pharmacology, molecular docking and ubiquitination analysis

Atractylenolide III (AT III) is a promising drug used for cancer treatment. Herein, this study aimed to explore the anti-tumor mechanism of AT III in breast cancer (BC) associated with murine double minute 2 (MDM2) and p53 through network pharmacology, molecular docking, ubiquitination analysis and cell experiments. The common targets between AT III and BC were obtained using Venn diagram followed by screening of hub targets using network pharmacology analysis. Molecular docking between AT III and hub targets (MAPK1, MDM2, and PPARG) was performed by AutoDock vina software, and docking results were evaluated by molecular dynamics simulation. Cell viability, proliferation, apoptosis, and migration/invasion were assessed through cell counting kit-8 (CCK-8), colony formation assay, flow cytometry and transwell assay. Western blot was performed for protein detection. AT III and MDM2 binding was analyzed by cellular thermal shift assay (CETSA). The ubiquitination effect of AT III on p53 was researched using ubiquitination assay. Network pharmacology analysis has screened three hub targets MAPK1, MDM2, and PPARG. Molecular docking and dynamic simulation showed the high binding between AT III and MAPK1, MDM2, or PPARG. AT III treatment significantly impeded proliferation, migration and invasion while promoting apoptosis of BC cells. AT III could bind to MDM2 and inhibit the ubiquitination of p53. MDM2/p53 reversed the anti-cancer regulation of AT III in BC cells. These results identified MDM2 as a target of AT III, and AT III played a tumor-inhibiting role in BC by mediating ubiquitination of p53 through targeting MDM2.