用于化学预防剂筛选的转基因细胞模型的建立

Establishment of a Transgenic Cell Model for Preliminary Screening of Chemopreventive Agents

摘要:

建立TK启动子以及抗氧化反应元件（ARE）增强子调控报告基因GFP在HepG₂细胞中稳定表达的细胞模型。人工合成ARE增强子序列，经退火和磷酸化后插入pTK-GFP载体的TK启动子上游，构建pARE-TK-GFP重组质粒。PCR法扩增TK和ARE-TK目的片段克隆到pEGFP-N₁上，构建TK启动子启动以及上游由ARE增强子调控的报告基因表达载体pTK-GFP/Neo和pARE-TK-GFP/Neo。脂质体转染法转染人HepG₂肝癌细胞后加G418筛选出阳性克隆。经扩大培养的克隆细胞中加入化学预防剂PDTC和香菇多糖作用48h后检测细胞中GFP荧光强度，结果显示pARE-TK-GFP/Neo表达载体中的GFP基因受ARE增强子的调控，其表达水平高于对照载体且在一定范围内与化学预防剂的浓度呈剂量效应关系，从而表明所构建的细胞模型可用于各种天然或人工合成的化学预防剂的初步筛选

Abstract:

To develop a GFP transgenic cell model under the transcriptional control of TK promoter adjacent to which ARE enhancer was inserted. Synthetic oligonucleotide ARE motif was annealed and purified then inserted into pTK-GFP to construct the vector of pARE-TK-GFP. The TK and ARE-TK fragments were amplified by PCR and cloned into pEGFP-N₁ to reconstruct eukaryotic expression vectors of pTK-GFP/Neo and pARE-TK-GFP/Neo. They were transfected into HepG^{2 cells and clones resistant G418 were isolated. PDTC and Lentinan were used to induce the cell levels of GFP and the fluorescence was measured using a fluorescence plate reader. The results showed that the induced level of GFP is significantly increased and have dose-dependeny in a certain range. This findings indicated that such a cell model offered a potential platform for preliminary screening of all kinds of natural or synthetic chemopreventive agents.}