Brockstedt Dirk G, Diagana Melissa, Zhang Ying, Tran Kimvan, Belmar Nicole, Meier Melinda, Yang Adrienne, Boissiere Florence, Lin Augustine, Chiang Yawen
Aventis Gencell, 3825 Bay Center Place, Hayward, California 94520, USA.
Mol Ther. 2002 Nov;6(5):627-36.
Gene therapy for cancer using suicide genes such as the herpes simplex virus thymidine kinase gene (HSVtk) has been explored extensively in preclinical and clinical studies. We have improved the use of HSVtk by combining it with two cytokine genes encoding granulocyte/macrophage-colony-stimulating factor (GM-CSF) and interleukin-2 (IL-2), and determined their additive/synergistic effects on tumor regression and inhibition of metastases in the non-immunogenic, spontaneously metastatic mammary tumor model, 4T1. Two adenoviral vectors (AV) were constructed, one carrying HSVtk (AV-TK) and the second (AV-GM/IL2) carrying Gm-CSf and Il2. Only the combination of AV-TK/GCV and AV-GM/IL2 showed a significant decrease in tumor growth and reduction of distant metastases with 25% of the tumors undergoing complete regression. When surgical excision of primary tumors was included in the regimen, local treatment with AV-TK/GCV plus AV-GM/IL2 further enhanced long-term survival. A fraction of the treated mice developed anti-tumor immunity and survived a second challenge with 4T1. Functional analyses demonstrated infiltration of lymphocytes within the tumor and a strong tumor-specific cytotoxic T lymphocyte response in TK- plus cytokine-treated animals. These data indicate that the coexpression of GM-CSF and IL-2 can augment the effect of HSVtk suicide gene therapy.
利用单纯疱疹病毒胸苷激酶基因（HSVtk）等自杀基因进行癌症基因治疗已在临床前和临床研究中得到广泛探索。我们通过将HSVtk与编码粒细胞/巨噬细胞集落刺激因子（GM-CSF）和白细胞介素-2（IL-2）的两个细胞因子基因相结合，改进了HSVtk的应用，并在非免疫原性、自发转移的乳腺肿瘤模型4T1中确定了它们对肿瘤消退和转移抑制的相加/协同作用。构建了两种腺病毒载体（AV），一种携带HSVtk（AV-TK），另一种（AV-GM/IL2）携带Gm-CSf和Il2。只有AV-TK/GCV和AV-GM/IL2的组合显示肿瘤生长显著减少，远处转移减少，25%的肿瘤完全消退。当在治疗方案中加入原发性肿瘤的手术切除时，用AV-TK/GCV加AV-GM/IL2进行局部治疗可进一步提高长期生存率。一部分接受治疗的小鼠产生了抗肿瘤免疫力，并在第二次接种4T1后存活下来。功能分析表明，在TK加细胞因子治疗的动物中，肿瘤内有淋巴细胞浸润，并有强烈的肿瘤特异性细胞毒性T淋巴细胞反应。这些数据表明，GM-CSF和IL-2的共表达可以增强HSVtk自杀基因治疗的效果。
