Cytochalasin B-Induced Membrane Vesicles from TRAIL-Overexpressing Mesenchymal Stem Cells Induce Extrinsic Pathway of Apoptosis in Breast Cancer Mouse Model

Tumor-necrosis-factor-associated apoptosis-inducing ligand (TRAIL) is one of the most promising therapeutic cytokines that selectively induce apoptosis in tumor cells. It is known that membrane vesicles (MVs) can carry the surface markers of parental cells. Therefore, MVs are of interest as a tool for cell-free cancer therapy. In this study, membrane vesicles were isolated from TRAIL-overexpressing mesenchymal stem cells using cytochalasin B treatment (CIMVs). To evaluate the antitumor effect of CIMVs-TRAIL in vivo, a breast cancer mouse model was produced. The animals were intratumorally injected with 50 µg of native CIMVs or CIMVs-TRAIL for 12 days with an interval of two days. Then, tumor growth rate, tumor necrotic area, the expression of the apoptosis-related genes CASP8, BCL-2, and BAX and the level of CASP8 protein were analyzed. A 1.8-fold increase in the CAS8 gene mRNA and a 1.7-fold increase in the CASP8 protein level were observed in the tumors injected with CIMVs-TRAIL. The expression of the anti-apoptotic BCL-2 gene in the CIMV-TRAIL group remained unchanged, while the mRNA level of the pro-apoptotic BAX gene was increased by 1.4 times, which indicated apoptosis activation in the tumor tissue. Thus, CIMVs-TRAIL were able to activate the extrinsic apoptosis pathway and induce tumor cell death in the breast cancer mouse model.