Jaceidin Inhibits Proliferation and Promotes Apoptosis in Oral Squamous Cell Carcinoma Cells by Regulating Survivin and AKT/ERK Signaling Pathways

Abstract

Oral squamous cell carcinoma (OSCC) remains a clinically challenging malignancy because of recurrence, treatment resistance, and limited therapeutic efficacy in advanced disease. This study investigated the anticancer effects and molecular mechanisms of jaceidin (JAC), a naturally occurring flavonoid derivative, in human OSCC cells. SCC-1 and SCC-47 cells were treated with JAC, and cell viability, colony formation, cell cycle distribution, apoptosis, and apoptosis-related signaling pathways were examined. JAC reduced OSCC cell viability and colony formation in a dose- and time-dependent manner. It also induced G2/M cell cycle accumulation and decreased the expression of cyclin D1, cyclin E1, phosphorylated cdc2, and CDK2/4/6. Apoptosis analyses showed that JAC promoted caspase-dependent apoptotic signaling, as evidenced by increased cleavage of caspase-3, caspase-8, caspase-9, and PARP. JAC modulated death receptor-associated signaling, characterized by increased Fas, TRADD, and DR5 expression and caspase-8 cleavage, while the decoy receptors DcR2 and DcR3 were also upregulated. JAC also promoted mitochondrial apoptotic signaling by increasing Bax, Bak, and Bim expression while decreasing Mcl-1. In addition, JAC attenuated AKT and ERK1/2 phosphorylation, and pharmacological inhibition with LY294002 or U0126 further enhanced JAC-induced apoptotic signaling. Furthermore, JAC reduced survivin expression and attenuated survivin-mediated apoptotic resistance. These findings suggest that JAC suppresses OSCC cell survival in association with modulation of AKT/ERK–survivin signaling and caspase-dependent apoptosis.