CXCR4启动子的克隆及在MCF-7乳腺癌细胞中的特异转录活性

Cloning of CXCR4 promoter and its specific transcriptional activity in MCF-7 breast cancer cell

目的证实CXCR4启动子在乳腺癌细胞MCF-7中的特异转录活性。方法采用PCR方法扩增CXCR4启动子序列,将其分别克隆到含有报告基因增强绿色荧光蛋白(EGFP)的质粒载体pEGFP-1和含有Luciferase的质粒载体pGL3-Basic,经脂质体分别转染人正常乳腺上皮细胞系HBL-100和乳腺癌细胞MCF-7,荧光显微镜下观察EGFP的表达情况,同时测定两种细胞中荧光素酶表达的差异。结果CXCR4基因的启动子在肿瘤细胞中呈现高的转录活性;而在正常细胞中转录活性极低。结论CXCR4启动子在乳腺癌MCF-7细胞中具有很强的特异性,为进一步开发肿瘤的特异性基因治疗奠定了实验基础。

[Objective] To identgy the specific transcription of CXCR4 promoter in MCF-7 breast cancer ceils. [Methods] CXCR4 gene minimal promoter was PCR amplified anti cloned into the reporter plasrnid pEGFP-1 and pGL3-Basie. The constructs pEGFP/CXCR4 and pGL.3/CXCR4 were transfeeted into MCF-7 breast cancer cell and HBL-100 human epitheli＇,d cells respectively. The expression of EGFP and lueiferase were investigated respectively. [Results] 279 bp CXCR4 gene minimal promoter was obtained successfully by PCR from MCF-7 cell genomie DNA and pEGFP/CXC1R4 and pGL3/CXCR4 bearing CXCR4 gene promoter were constructed. At 20 hour post trans- feetion, the speeifie expression of the EGFP was detected in MCF-7 cell while litde expression of EGFP was in HBL-100 cell. In accordance with EGFP, lueiferase driven by CXCR4 also showed specific and high activity. [ Conclusion] The high transcriptional activity of CXCR4 gene promoter in MCF-7 cell indicates its potential utility as a novel candidate for transcriptional targeting of breast eancer.