Tannous Bakhos A, Christensen Adam P, Pike Lisa, Wurdinger Thomas, Perry Katherine F, Saydam Okay, Jacobs Andreas H, García-Añoveros Jaime, Weissleder Ralph, Sena-Esteves Miguel, Corey David P, Breakefield Xandra O
Department of Neurology, Molecular Neurogenetics Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02129, USA.
Mol Ther. 2009 May;17(5):810-9. doi: 10.1038/mt.2009.33. Epub 2009 Mar 3.
Viral vectors have been used to deliver a wide range of therapeutic genes to tumors. In this study, a novel tumor therapy was achieved by the delivery of a mammalian brain sodium channel, ASIC2a, carrying a mutation that renders it constitutively open. This channel was delivered to tumor cells using a herpes simplex virus-1/Epstein-Barr virus (HSV/EBV) hybrid amplicon vector in which gene expression was controlled by a tetracycline regulatory system (tet-on) with silencer elements. Upon infection and doxycycline induction of mutant channel expression in tumor cells, the open channel led to amiloride-sensitive sodium influx as assessed by patch clamp recording and sodium imaging in culture. Within hours, tumor cells swelled and died. In addition to cells expressing the mutant channel, adjacent, noninfected cells connected by gap junctions also died. Intratumoral injection of HSV/EBV amplicon vector encoding the mutant sodium channel and systemic administration of doxycycline led to regression of subcutaneous tumors in nude mice as assessed by in vivo bioluminescence imaging. The advantage of this direct mode of tumor therapy is that all types of tumor cells become susceptible and death is rapid with no time for the tumor cells to become resistant.
病毒载体已被用于将多种治疗性基因递送至肿瘤。在本研究中，通过递送一种携带使其组成性开放的突变的哺乳动物脑钠通道ASIC2a，实现了一种新型肿瘤治疗方法。该通道通过单纯疱疹病毒1型/爱泼斯坦-巴尔病毒（HSV/EBV）杂交扩增载体递送至肿瘤细胞，其中基因表达由带有沉默元件的四环素调控系统（四环素诱导）控制。在肿瘤细胞中感染并经强力霉素诱导突变通道表达后，通过膜片钳记录和培养中的钠成像评估，开放通道导致了amiloride敏感的钠内流。数小时内，肿瘤细胞肿胀并死亡。除了表达突变通道的细胞外，通过间隙连接相连的相邻未感染细胞也死亡。通过体内生物发光成像评估，瘤内注射编码突变钠通道的HSV/EBV扩增载体并全身给予强力霉素可导致裸鼠皮下肿瘤消退。这种直接的肿瘤治疗方式的优点是所有类型的肿瘤细胞都变得敏感且死亡迅速，肿瘤细胞没有时间产生抗性。
