Wu X, He Y, Falo L D, Hui K M, Huang L
Center for Pharmacogenetics, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
Mol Ther. 2001 Mar;3(3):368-74. doi: 10.1006/mthe.2001.0280.
The tumor necrosis factor (TNF)-related apoptosis-inducing ligand, TRAIL, is a new member of the TNF family. It can specifically induce apoptosis in a variety of human tumors. To investigate the possibility of employing the TRAIL gene for systemic cancer therapy, we constructed a recombinant gene encoding the soluble form of the human Flt3L gene (hFlex) at the 5' end and the human TRAIL gene at the 3' end. Such design allows the TRAIL gene product to be secreted into the body circulation. We have also demonstrated that the addition of an isoleucine zipper to the N-terminal of TRAIL greatly enhanced the trimerization of the fusion protein and dramatically increased its anti-tumor activity. The fusion protein reached the level of 16-38 microg/ml in the serum after a single administration of the recombinant gene by hydrodynamic-based gene delivery in mice. A high level of the fusion protein correlated with the regression of a human breast tumor established in SCID mice. No apparent toxicity was observed in the SCID mouse model. In addition, the fusion protein caused an expansion of the dendritic cell population in the C57BL/6 recipient mice, indicating that the hFlex component of the fusion protein was functional. Thus, the hFlex-TRAIL fusion protein may provide a novel approach, with the possible involvement of dendritic cell-mediated anti-cancer immunity, for the treatment of TRAIL-sensitive tumors.
肿瘤坏死因子（TNF）相关凋亡诱导配体（TRAIL）是TNF家族的新成员。它能特异性诱导多种人类肿瘤细胞凋亡。为了研究利用TRAIL基因进行全身性癌症治疗的可能性，我们构建了一个重组基因，其5'端编码人Flt3L基因（hFlex）的可溶性形式，3'端编码人TRAIL基因。这种设计使得TRAIL基因产物能够分泌到体循环中。我们还证明，在TRAIL的N端添加异亮氨酸拉链可大大增强融合蛋白的三聚化，并显著提高其抗肿瘤活性。通过水动力基因递送在小鼠单次注射重组基因后，血清中融合蛋白水平达到16 - 38微克/毫升。融合蛋白的高浓度与SCID小鼠中建立的人乳腺肿瘤的消退相关。在SCID小鼠模型中未观察到明显毒性。此外，融合蛋白导致C57BL/6受体小鼠中树突状细胞群体扩增，表明融合蛋白的hFlex成分具有功能。因此，hFlex - TRAIL融合蛋白可能为TRAIL敏感肿瘤的治疗提供一种新方法，可能涉及树突状细胞介导的抗癌免疫。
