肿瘤靶向腺相关病毒携带干扰素β和TRAIL对A549肺癌移植瘤的增强治疗效应

Enhanced antitumor effect of combining interferon β with TRAIL mediated by tumor-targeting adeno-associated virus vector on A549 lung cancer xenograft

摘要:

干扰素β(IFN-β) 和肿瘤坏死因子相关凋亡诱导配体 (TRAIL) 是有效抗癌药物。腺相关病毒(AAV) 为目前最有应用前景的基因转移载体之一。利用AAV携带IFN-β和TRAIL基因并置于hTERT启动子控制下分别构建成肿瘤靶向病毒AAV-hTERT-IFN-β和AAV-hTERT-TRAIL，且单个IFN-β或TRAIL基因治疗发挥了一定的抗癌效果。将AAV-hTERT-IFN-β和AAV-hTERT-TRAIL进行联合，旨在研究其对A549肺癌细胞体内外的生长抑制效应。ELISA法检测了AAV-hTERT-IFN-β感染A549细胞后分泌型IFN-β的表达；MTT法检测AAV-hTERT-IFN-β联合AAV-hTERT-TRAIL对肿瘤细胞的生长抑制作用；凋亡细胞染色和流式细胞仪分别检测了AAV-hTERT-IFN-β、AAV-hTERT-TRAIL及其联合对A549细胞的凋亡效应；进一步评价了联合AAV-hTERT-IFN-β和 AAV-hTERT-TRAIL对A549裸鼠移植瘤的抑癌效果。结果显示，联合治疗优于任一单独治疗并且导致了增强的肿瘤细胞毒性和凋亡诱导效应。更进一步显示，联合AAV-hTERT-IFN-β和AAV-hTERT-TRAIL治疗发挥了重要的抑制裸鼠移植瘤效果甚至消除全部移植瘤，为探究IFN-β和TRAIL联合抗癌的分子机制奠定了基础。

Abstract:

Interferon β (IFN-β) and TNF-related apoptosis-inducing ligand (TRAIL) are effective anticancer agents. Adeno-associated virus (AAV) is one of the current most promising gene delivery vectors. Previously, we constructed tumor-targeting AAV-hTERT-IFN-β and AAV-hTERT-TRAIL by inserting IFN-β or TRAIL gene into AAV controlled by hTERT promoter. The studies showed that either single IFN-β or TRAIL gene therapy exhibited a certain extent anticancer effect. Here, we report their inhibitory effects on A549 lung cancer cell growth in vitro and in vivo by combined AAV-hTERT-IFN-β and AAV-hTERT-TRAIL. Expression of secreted IFN-β in lung cancer A549 cells infected by AAV-hTERT-IFN-β was detected by enzyme-linked immunosorbent assay (ELISA). The growth-suppressing effect of AAV-hTERT-IFN-β in combination with AAV-hTERT-TRAIL on several cancer cell lines was assessed by MTT assay. Apoptosis of A549 cancer cells infected by AAV-hTERT-IFN-β alone, AAV-hTERT-TRAIL alone, and their combination was evaluated by apoptotic cell staining and flow cytometry (FCM), respectively. The antitumor effect of the combination of AAV-hTERT-IFN-β with AAV-hTERT-TRAIL in vivo was further evaluated through A549 lung cancer xenograft in nude mice. The results showed that the combinational treatment was superior to any alone and presented intensified tumor cytotoxic and apoptotic effect on A549 cancer cells. Most importantly, the combination of AAV-hTERT-IFN-β with AAV-hTERT-TRAIL exhibited significant antitumor effect and eliminated all tumor masses in nude mice, which lay a foundation for exploring the molecular mechanisms of combined IFN-β and TRAIL anti-tumor activity.