Hingtgen Shawn, Ren Xianghui, Terwilliger Ernie, Classon Marie, Weissleder Ralph, Shah Khalid
Massachusetts General Hospital, Harvard Medical School, 13th Street, Charlestown, MA 02129, USA.
Mol Cancer Ther. 2008 Nov;7(11):3575-85. doi: 10.1158/1535-7163.MCT-08-0640.
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively kills tumor cells. However, its short half-life, poor delivery, and TRAIL-resistant tumor cells have diminished its clinical efficacy. In this study, we explored whether novel delivery methods will represent new and effective ways to treat gliomas and if adjuvant therapy with the chemotherapeutic agent temozolomide would enhance the cytotoxic properties of TRAIL in glioma lines resistant to TRAIL monotherapy. We have engineered adeno-associated virus (AAV) vectors encoding recombinant secreted TRAIL (S-TRAIL) and bioluminescent-fluorescent marker fusion proteins and show that AAV-delivered S-TRAIL leads to varying degrees of killing in multiple glioma lines, which correspond with caspase-3/7 activation. In vivo, dual bioluminescent imaging revealed efficient delivery of therapeutic AAV vectors directly into the tumor mass, which induced marked attenuation of tumor progression. Treatment of glioma cells with the chemotherapeutic agent temozolomide alone lead to a significant accumulation of cells in G(2)-M phase, activated the cell cycle checkpoint protein Chk1, and increased death receptor expression in a time-dependent manner. Furthermore, combined treatment with AAV-S-TRAIL or neural stem cell-S-TRAIL and temozolomide induced cell killing and markedly up-regulated proapoptotic proteins in glioma cells least sensitive to TRAIL. This study elucidates novel means of delivering S-TRAIL to gliomas and suggests combination of clinically relevant temozolomide and S-TRAIL may represent a new therapeutic option with increased potency for glioblastoma patients.
肿瘤坏死因子相关凋亡诱导配体（TRAIL）可选择性杀死肿瘤细胞。然而，其半衰期短、递送效果差以及存在对TRAIL耐药的肿瘤细胞，这些因素削弱了它的临床疗效。在本研究中，我们探究了新型递送方法是否会成为治疗胶质瘤的新的有效途径，以及化疗药物替莫唑胺的辅助治疗是否会增强TRAIL对单药治疗耐药的胶质瘤细胞系的细胞毒性。我们构建了编码重组分泌型TRAIL（S-TRAIL）和生物发光-荧光标记融合蛋白的腺相关病毒（AAV）载体，并表明AAV递送的S-TRAIL可在多个胶质瘤细胞系中导致不同程度的杀伤，这与半胱天冬酶-3/7的激活相对应。在体内，双生物发光成像显示治疗性AAV载体可有效直接递送至肿瘤块中，从而显著减缓肿瘤进展。单独用化疗药物替莫唑胺处理胶质瘤细胞会导致细胞在G(2)-M期显著积累，激活细胞周期检查点蛋白Chk1，并以时间依赖性方式增加死亡受体表达。此外，AAV-S-TRAIL或神经干细胞-S-TRAIL与替莫唑胺联合治疗可诱导对TRAIL最不敏感的胶质瘤细胞杀伤，并显著上调促凋亡蛋白。本研究阐明了将S-TRAIL递送至胶质瘤的新方法，并表明临床相关的替莫唑胺和S-TRAIL联合使用可能为胶质母细胞瘤患者提供一种新的、效力更高的治疗选择。
