Abstract：
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.
摘要：
肿瘤坏死因子相关的凋亡诱导配体（TRAIL）是选择性诱导肿瘤细胞凋亡的最有前途的治疗细胞因子之一。已知膜囊泡(MV)可以携带亲本细胞的表面标记。因此,MV作为无细胞癌症治疗的工具是令人感兴趣的。在这项研究中,使用细胞松弛素B处理(CIMV)从过表达TRAIL的间充质干细胞中分离膜囊泡。为了评估CIMVs-TRAIL的体内抗肿瘤作用，制作了乳腺癌小鼠模型。对动物进行瘤内注射50µg的nativeCIMVs或CIMVs-TRAIL12天，间隔两天。然后，肿瘤生长速率,肿瘤坏死区，分析细胞凋亡相关基因CASP8、BCL-2和BAX的表达及CASP8蛋白水平。在注射CIMVs-TRAIL的肿瘤中观察到CAS8基因mRNA增加1.8倍，CASP8蛋白水平增加1.7倍。抗凋亡BCL-2基因在CIMV-TRAIL组中的表达保持不变，而促凋亡BAX基因的mRNA水平增加了1.4倍，这表明肿瘤组织中的细胞凋亡激活。因此，在乳腺癌小鼠模型中，CIMVs-TRAIL能够激活外源性凋亡途径并诱导肿瘤细胞死亡。
