Cantharidin Suppresses Cell Viability and Induces Apoptosis of SK-N-SH and SH-SY5Y Cells

Neuroblastoma (NBL) is a pediatric malignancy with high mortality, particularly within the first year of life. Cantharidin, a natural terpenoid derived from blister beetles, has shown anticancer activity against several malignancies; however, its effect on NBL remains unexplored. In this study, we evaluated the antiproliferative and pro-apoptotic effects of cantharidin on SH-SY5Y and SK-N-SH NBL cell lines. The cell viability and appearance of sub-G1 were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry, respectively. The alterations of apoptosis-related molecules were determined by western blotting. MTT assays revealed that treatment with 5 and 10 μM cantharidin for 24 and 48 h significantly reduced viability of both SH-SY5Y and SK-N-SH cells (all p<0.05), with 10 μM for 48 h reducing viability by 65.3% and 72.3%, respectively. Flow cytometry showed that 10 μM cantharidin induced apoptosis of 51.0% of SH-SY5Y and 68.3% of SK-N-SH cells at 48 h (p<0.05). Western blot analysis demonstrated increased expression of cleaved caspase-3, -8 and -9, and pro-apoptotic proteins BCL2-associated X (BAX) and BH3-interacting domain death agonist (BID), alongside reduced levels of anti-apoptotic BCL2 apoptosis regulator (BCL2) and B-cell lymphoma-extra large (BCL-xL). Cytochrome c release was also elevated, confirming mitochondrial pathway involvement. Additionally, phosphorylation of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) was significantly suppressed by 10 μM cantharidin at 48 h, suggesting JAK2 and STAT3 pathway inhibition contributes to apoptosis. These findings support the hypothesis that cantharidin induces apoptosis via both intrinsic and extrinsic pathways, as well as through suppression of the JAK2-STAT3 axis. Our results reveal that cantharidin holds significant promise as a multi-target therapeutic candidate for NBL, justifying additional in vivo validation and clinical translation efforts.