Expression of the Apoptotic Proteins in Glioblastoma U87-MG Cell Line Treated by Botulinum Toxin

Background: Glioblastoma multiforme (GBM) is the most type of brain malignancy in adults. Radical excision surgery, chemotherapy, and radiotherapy in some cases are still unsuccessful, and most patients with GBM die within three to six months following diagnosis. Botulinum toxin type A (BtxA) has cellular toxin effects and suppresses the cell division of certain types of cancer cell lines in vivo and in vitro study. The present study designed to evaluate the apoptotic effect of BtxA on the GBM cell line.

Material & methods: U87-MG GBM cell line cultured according to the routing protocols, divided into two groups including, trial (BtxA treated) and control groups. Cells of the trial group exposed to different doses of BtxA. The cell viability, cycle arrest, and pro-apoptotic proteins evaluated respectively by MTT assay, SubG1, and Western blotting.

Results: MTT assay showed that the viability of the BtxA treated cells at doses of 1.45 Unit and other doses after 24 to 48 hours, significantly decreased (p<0.001) compared to the control groups. Apoptosis percentage of the SubG1 test also indicated that 1.45 Unit dose significantly increased in the cells exposed to BtxA compared to the control group in 24 hours. The expression of P53 and Caspase 3 proteins indicated a significant increase.

Conclusion: BtxA induces apoptosis in U87- MG cell line via p53 and caspase three pathways and could have clinical applications. In vivo studies need to confirm the clinical application of the present findings.