Abstract:
Objective To clone core sequence of hTERT promoter,and study transcriptional activity of hTERT promoter/SV40 enhancer in esophageal cancer cell. Methods hTERT promoter was amplified from human genomic DNA using polymerase chain reaction (PCR);hTERT promoter was inserted into pGL3-Basic and pGL3-enhancer to construct luciferase gene expression driven by hTERT promoter(named as pGL3-hTERTp) or by hTERT promter/SV40 enhancer(named as pGL3-hTERTp-SV40en),respectively.The recombinants were transiently transfected into esophageal cancer cells of Eca-109,EC1 and human embryo lung fibroblast MRC-5, respectively,then expression level of luciferase gene in transfected cells was studied to evaluate transcriptional activities of hTERT promoter and hTERT promoter/SV40 enhancer in esophageal cancer cells. Results A 213 bp core-sequence of hTETR promoter was cloned successfully,and DNA sequencing showed its sequence the same as that registered in GenBank;recombinants of pGL3-hTERTp and pGL3-hTERTp-SV40en were successfully constructed.hTERT promoter had transcriptional activity in esophageal cancer cells while no transcriptional activity in MRC-5 cells;The transcriptional level of hTERT promoter/SV40 enhancer in esophageal cancer cells was significantly higher than hTERT promoter alone. Conclusion hTERT promoter has selective transcriptional activity in esophageal cancer cells;SV40 enhancer could significantly elevate transcriptional level of hTERT promoter,and it could play an important role in targeting gene therapy for tumor.