Rabdosin B suppresses proliferation of nonsmall cell lung cancer by regulating the SRC/PI3K/AKT signaling pathway

Rabdosin B (RB), an active compound derived from the Chinese herb Isodon japonicus (Burm. f.) H. Hara, has demonstrated inhibitory effects on non-small cell lung cancer (NSCLC) cell proliferation in prior studies. However, its precise mechanism of action remains unclear.

To investigate the mechanism of RB against NSCLC and its synergistic effect with cisplatin (CDDP) via the SRC/PI3K/AKT signaling pathway.

In vitro assays, CCK-8, colony formation, flow cytometry, scratch, Transwell, and Western blot assessed proliferation, apoptosis and migration. Network pharmacology, molecular docking, molecular dynamics simulation (MDS) and cellular thermal shift assay (CETSA) were employed to validate molecular targets. King's formula was used to evaluate the combined effect of RB and CDDP, with xenograft models confirming in vivo efficacy.

In vitro, RB significantly suppressed NSCLC proliferation, migration, and invasion while inducing apoptosis. Mechanistically, network pharmacology predicted SRC as a core target. MDS and CETSA subsequently confirmed the direct and stable binding of RB to SRC. Western blot analysis revealed that RB exerted its effect by inhibiting SRC/PI3K/AKT signaling. Notably, RB synergistically enhanced CDDP sensitivity by blocking SRC/PI3K/AKT pathway activation, thereby potentiating apoptosis. Finally, in vivo experiments validated that RB effectively suppressed tumor growth with favorable safety.

RB inhibits NSCLC progression and sensitizes cells to CDDP by directly targeting SRC to inactivate the PI3K/AKT pathway. These findings identify a novel mechanism of RB against NSCLC and suggest its potential as a therapeutic strategy.