Groenlandicine enhances cisplatin sensitivity in cisplatin-resistant osteosarcoma cells through the BAX/Bcl-2/Caspase-9/Caspase-3 pathway

Groenlandicine is a protoberberine alkaloid isolated from Coptidis Rhizoma, a widely used traditional Chinese medicine known for its various biological activities. This study aims to validate groenlandicine's effect on both cisplatin-sensitive and cisplatin-resistant osteosarcoma (OS) cells, along with exploring its potential molecular mechanism. The ligand-based virtual screening (LBVS) method and molecular docking were employed to screen drugs. CCK-8 and FCM were used to measure the effect of groenlandicine on the OS cells transfected by lentivirus with over-expression or low-expression of TOP1. Cell scratch assay, CCK-8, FCM, and the EdU assay were utilized to evaluate the effect of groenlandicine on cisplatin-resistant cells. WB, immunofluorescence, and PCR were conducted to measure the levels of TOP1, Bcl-2, BAX, Caspase-9, and Caspase-3. Additionally, a subcutaneous tumor model was established in nude mice to verify the efficacy of groenlandicine. Groenlandicine reduced the migration and proliferation while promoting apoptosis in OS cells, effectively damaging them. Meanwhile, groenlandicine exhibited weak cytotoxicity in 293T cells. Combination with cisplatin enhanced tumor-killing activity, markedly activating BAX, cleaved-Caspase-3, and cleaved-Caspase-9, while inhibiting the Bcl2 pathway in cisplatin-resistant OS cells. Moreover, the level of TOP1, elevated in cisplatin-resistant OS cells, was down-regulated by groenlandicine both in vitro and in vivo. Animal experiments confirmed that groenlandicine combined with cisplatin suppressed OS growth with lower nephrotoxicity. Groenlandicine induces apoptosis and enhances the sensitivity of drug-resistant OS cells to cisplatin via the BAX/Bcl-2/Caspase-9/Caspase-3 pathway. Groenlandicine inhibits OS cells growth by down-regulating TOP1 level.Therefore, groenlandicine holds promise as a potential agent for reversing cisplatin resistance in OS treatment.