The potential of 5-fluorocytosine/cytosine deaminase enzyme prodrug gene therapy in an intrahepatic colon cancer model
The potential of 5-fluorocytosine/cytosine deaminase enzyme prodrug gene therapy in an intrahepatic colon cancer model
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DOI：
10.1038/sj.gt.3301706
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发表时间：
2002-07-01
期刊：
影响因子：
5.1
通讯作者：
Lawrence, TS
中科院分区：
文献类型：
--
作者：
Nyati, MK;Symon, Z;Lawrence, TS
结直肠癌可以转移到肝脏，但多年来仍局限于肝脏。开发肝内癌治疗方法的关键一步涉及原位肝内模型的评估。本研究的目的是开发一种非侵入性肝内肿瘤模型，以研究基于 5-氟胞嘧啶/酵母胞嘧啶脱氨酶（5FC/yCD）的基因治疗对肝脏肿瘤的疗效。通过逆转录病毒感染产生表达荧光素酶的人结直肠癌（HT-29luc）细胞，并将其植入裸鼠的左肝叶中。每周测量生物发光，持续1个月，然后处死动物并用卡尺测量肿瘤。在我们发现光子计数与肿瘤大小之间的相关性后，动物被植入由 0%、10% 或 10% 组成的肿瘤；或 100% yCD/HHT-29luc 细胞，并用 5FC 处理。在治疗期间测量肿瘤生物发光，并在死亡时检查肿瘤组织学。我们发现 5FC 导致表达 yCD 的肿瘤显着消退。此外，死亡时可见的肿瘤几乎不发出生物发光，几乎不含或根本不含存活的肿瘤。然后我们开发了 yCD 的腺病毒载体。腹腔内给予含有 yCD 的腺病毒导致肝内肿瘤内产生 yCD 酶。这些结果表明（1）当细胞表达yCD时，肝内癌对5FC有反应； (2)荧光素-荧光素酶系统允许对活的肝内癌进行非侵入性实时成像； (3)该系统可用于利用yCD腺病毒进行基因治疗实验。
Colorectal cancer can metastasize to the liver, but remain liver confined for years. A critical step in developing treatments for intrahepatic cancer involves assessment in an orthotopic intrahepatic model. The purpose of this study was to develop a noninvasive intrahepatic tumor model to study the efficacy of 5-flucytosine/yeast cytosine deaminase (5FC/yCD)-based gene therapy for liver tumors. Luciferase expressing human colorectal carcinoma (HT-29luc) cells were generated by retroviral infection and implanted in the left liver lobe of nude mice. The bioluminescence was measured every week for a period of 1 month, then animals were killed and tumors were measured by calipers. After we found a correlation between photon counts and tumor size, animals were implanted with tumors composed of either 0%, 10%; or 100% yCD/HHT-29luc cells, and treated with 5FC. Tumor bioluminescence was measured during treatment and tumor histology examined at the time of death. We found that 5FC caused significant regression of yCD expressing tumors. Furthermore, visible tumors at the time of death, which emitted little bioluminescence, contained little or no viable tumor. We then developed an adenoviral vector for yCD. Intraperitoneal administration of adenovirus containing yCD led to the production of yCD enzyme within intrahepatic tumors. These results suggest that (1) intrahepatic cancer responds to 5FC when cells express yCD; (2) the luciferin-luciferase system permits non-invasive real time imaging of viable intrahepatic cancer; and (3) this system can be used to carry out gene therapy experiments using yCD adenovirus.