A tumor suppressor gene, Cx26, also mediates the bystander effect in HeLa cells.
A tumor suppressor gene, Cx26, also mediates the bystander effect in HeLa cells.
复制标题
肿瘤抑制基因 Cx26 也在 HeLa 细胞中介导旁观者效应。
作者：
M. Mesnil;C. Piccoli;H. Yamasaki
连接蛋白26（Cx 26）基因在体外和体内抑制HeLa细胞的生长。我们探讨了Cx 26基因不仅抑制生长，而且还可以介导在一些基因治疗中观察到的旁观者效应的可能性。在单纯疱疹病毒胸苷激酶介导的基因治疗中，更昔洛韦的毒性不仅影响转导基因的细胞，还影响邻近的肿瘤细胞;有人认为间隙连接细胞间通讯（GJIC）可能在这种旁观者效应中发挥作用。用单纯疱疹病毒胸苷激酶（tk+）基因转染表达Cx 26基因（Cx 26+）或不表达Cx 26基因的HeLa细胞，产生Cx 26（-）-tk-、Cx 26（-）-tk+、Cx 26 +-tk-和Cx 26 +-tk+细胞。通过将这些细胞进行不同类型的共培养，我们观察到了明显的旁观者杀伤效应，通过中性红毒性试验评估，在Cx 26 +-tk-/Cx 26 +-tk+细胞的共培养中。旁观者效应被GJIC的长期抑制剂18-α-大黄酸显著阻止，这表明观察到的旁观者效应的主要部分通过Cx介导的GJIC发生。这些数据表明，使用Cxs作为肿瘤抑制基因和更昔洛韦毒性的扩散剂在治疗方法的可能性。
The connexin 26 (Cx26) gene suppresses the growth of HeLa cells in vitro and in vivo. We explored the possibility that the Cx26 gene not only suppresses growth but can also mediate the bystander effect that is observed in some gene therapy. In gene therapy mediated by the herpes simplex virus thymidine kinase, the toxicity of ganciclovir affects not only the cells transduced with the gene but also affects neighboring tumor cells; it has been suggested that gap junctional intercellular communication (GJIC) may play a role in such a bystander effect. HeLa cells expressing the Cx26 gene (Cx26+) or not expressing the Cx26 gene were transfected with the herpes simplex virus thymidine kinase (tk+) gene, producing Cx26(-)-tk-, Cx26(-)-tk+, Cx26+-tk-, and Cx26+-tk+ cells. By making different kinds of cocultures of these cells, we observed a clear bystander killing effect, assessed by the neutral red toxicity test, in the coculture of Cx26+-tk-/Cx26+-tk+ cells. The bystander effect was markedly prevented by a long-term inhibitor of GJIC, 18-alpha-glycyrrhetinic acid, demonstrating that a major part of the bystander effect seen occurred through Cx-mediated GJIC. These data suggest the possibility of using of Cxs as both tumor suppressor genes and as diffusers of ganciclovir toxicity in therapeutic approaches.