Purified herpes simplex virus thymidine kinase retroviral particles: III. Characterization of bystander killing mechanisms in transfected tumor cells
Purified herpes simplex virus thymidine kinase retroviral particles: III. Characterization of bystander killing mechanisms in transfected tumor cells
复制标题
DOI：
10.1038/sj/cgt/7700401
复制
发表时间：
2002-01-01
影响因子：
6.4
通讯作者：
Kruse, CA
中科院分区：
文献类型：
--
作者：
Burrows, FJ;Gore, M;Kruse, CA
自杀基因治疗范例的一个重要后果是旁观者细胞杀伤现象，即在用抗病毒药物更昔洛韦（GCV）治疗后，未被来自单纯疱疹病毒（HSV）的胸苷激酶（TK）基因转导的相邻肿瘤细胞的死亡。胶质瘤细胞系体外定量分析的证据表明，鼠和人胶质瘤在表达对旁观者效应的高敏感性方面是相似的。在所检查的六个神经胶质肿瘤中的五个中，培养物中仅存在5%的表达HSV-TK的转导细胞导致在添加GCV后>90%的肿瘤细胞死亡/停滞。许多证据支持间隙连接细胞间通讯（GJIC）在旁观者效应中起重要作用。在体外代谢试验中，与GCV在培养基中进行，表明更多的肿瘤负荷减少时，培养条件支持细胞-细胞接触的父母和HSV-TK-转导的细胞。此外，双染料转移测定显示，通过差距连接的细胞通讯对于神经胶质瘤最大，对于黑素瘤较少，并且对于结肠直肠癌细胞系少得多。TK+ /TK -同源肿瘤细胞混合物的体外代谢试验证实，胶质瘤细胞系比黑色素瘤更容易受到旁观者杀伤。用TK+ /TK -细胞的嵌合肿瘤混合物进行的测定表明，获得的旁观者杀伤水平是TK-旁观者细胞的特征。在体内用GCV处理的由TK+/TK-细胞组成的同源和嵌合肿瘤证实了体外结果。第21天的平均肿瘤体积（MTV）表明，获得的生长是旁观者活动的特征，反映了未转导的细胞群。此外，嵌合肿瘤块中的非转导的高GJIC细胞似乎有效地桥接转导的肿瘤细胞和沟通不良的非转导细胞。最后，利用HT 29低GJIC细胞系证明了间隙连接蛋白（例如连接蛋白-43）在促进旁观者效应方面的重要性。当TK-非转导的细胞群体表达连接蛋白-43时，与亲本对应物相比，实现了更好的旁观者杀伤。
An important consequence of the suicide gene therapeutic paradigm is the phenomenon of bystander cell killing, the death of adjacent tumor cells not transduced with the thymidine kinase (TK) gene from herpes simplex virus (HSV) after treatment with the antiviral drug, ganciclovir (GCV). Evidence from quantitative in vitro assays of glioma cell lines suggest that both murine and human gliomas are similar in expressing high sensitivity to the bystander effect. In five of six glial tumors examined, the presence of only 5% of HSV-TK-expressing transduced cells in the culture resulted in >90% tumor cell death/stasis after addition of GCV. Several lines of evidence support gap junction intercellular communication (GJIC) as important in the bystander effect. In vitro metabolic assays, performed with GCV in the medium, indicated that more tumor burden was reduced when culture conditions supported cell-cell contact of parental and HSV-TK-transduced cells. Additionally, a double dye transfer assay showed that cell communication through the gap junction is greatest for glioma, less for melanoma, and much less for colorectal carcinoma cell lines. In vitro metabolic assays with mixtures of TK+ /TK - homologous tumor cells confirmed that glioma cell lines were more susceptible to bystander killing than melanomas. Assays with chimeric tumor mixtures of TK+ /TK - cells showed that the level of the bystander killing obtained was characteristic of the TK- bystander cells. The in vitro findings were confirmed in vivo with GCV-treated homologous and chimeric tumors composed of TK+/TK- cells. Day 21 mean tumor volumes (MTVs) indicated the growths obtained were characteristic of the bystander activity reflective of the nontransduced cell population. Furthermore, nontransduced, high-GJICcells in a chimeric tumor mass appeared to effectively bridge between transduced tumor cells and poorly communicating nontransduced cells. Finally, the importance of a gap junction protein, such as connexin-43, in facilitating the bystander effect was demonstrated with the HT29 low-GJIC cell line. When the TK-nontransduced cell population expressed connexin-43, a better bystander kill was achieved compared to the parental counterpart.