Chelerythrine: a novel candidate for targeting miR-21/PTEN/PI3K/AKT in nasopharyngeal carcinoma.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is characterized by high metastatic potential and therapeutic resistance, necessitating the development of novel and safe therapeutic strategies. Hyperactivation of the PI3K/AKT signaling pathway, often driven by the oncogenic microRNA-21 (miR-21) and the subsequent suppression of PTEN, plays a key role in NPC progression. Chelerythrine (CHE), a natural plant-derived alkaloid, exhibits potent anti-tumor activities; however, its precise regulatory mechanisms and translational potential in NPC remain elusive.

METHODS: Network pharmacology was employed to predict the core downstream cascades of CHE against NPC. In vitro, CCK-8, real-time cellular analysis (RTCA), flow cytometry, wound healing, and Transwell assays were utilized to evaluate the specific cytotoxicity and anti-malignant effects of CHE in normal nasopharyngeal epithelial cells (NP69) and NPC cells (5-8 F and 6-10B). RT-qPCR was used to quantify the expression of primary (pri-miR-21), precursor (pre-miR-21), and mature miR-21. In vivo, a BALB/c nude mouse xenograft model was established to systematically assess the tumor-suppressive efficacy and macroscopic/histological biosafety of CHE. Furthermore, definitive rescue experiments were conducted using a specific PI3K activator and lentivirus-mediated miR-21 modification cell lines.

RESULTS: Network pharmacology highlighted the PI3K/AKT pathway as the key effector cascade of CHE. Functionally, CHE exhibited a highly favorable safety profile in NP69 cells and in vivo major organs, while significantly inhibiting NPC cell proliferation, migration, and invasion, and inducing apoptosis. Mechanistically, CHE synchronously suppressed the expression of pri-miR-21 and pre-miR-21, indicating a transcriptional downregulation of miR-21. This upstream suppression led to the restoration of the tumor suppressor PTEN, subsequent inactivation of the PI3K/AKT pathway, and reversal of the epithelial-mesenchymal transition (EMT) phenotype. Importantly, co-treatment with a PI3K activator or lentiviral overexpression of miR-21 significantly counteracted the tumor-suppressive effects of CHE, whereas miR-21 knockdown synergistically potentiated its efficacy.

CONCLUSION: Collectively, our findings indicate that CHE is a safe and effective therapeutic candidate for NPC. It exerts its anti-tumor and anti-metastatic effects by transcriptionally downregulating miR-21, thereby relieving PTEN suppression and systematically inactivating the PI3K/AKT signaling axis.