Cloning of hTERT promoter and its specific transcriptional activity in MCF7 breast cancer cell / 中国癌症杂志

ABSTRACT

Background and purpose:Gene therapy is a novel approach for the treatment of the patients with breast cancer. One of the effective ways is to direct transgenic expression to specific tissues or tumors with the use of tissue-specific-promoters (TSP). hTERT (human telomerase reverse transcriptase) is highly expressed in many types of cancers including breast cancer. Thus, we hypothesized that the hTERT promoter targeting with gene therapy vectors could be exploited for breast cancer. In this study, we amplified hTERT gene promoter and cloned it into the reporter vector pEGFP and pGL3-Basic. Afterwards, the specific transcription of hTERT promoter in MCF7 cells was evaluated. Methods:hTERT gene minimal promoter was PCR amplified and cloned into the reporter plasmid pEGFP-1 and pGL3-Basic.The constructs pEGFP/TERT and pGL3/TERT were transfected into MCF7 breast cancer cells and HBL100 human epithelial cells, respectively.The expression of EGFP and luciferase were investigated, respectively..Results:pEGFP/TERT and pGL3 /TERT bearing hTERT gene promoter were constructed. The specific expression of EGFP was detected in MCF7 cells while little expression of EGFP was seen in HBL100 cells.In accordance with EGFP, luciferase driven by hTERT also showed specific and high activity in MCF7 cell (RLU/U 33784), which is 15 times higher than in HBL100 (RLU/U 2400).Conclusions:The high transcriptional activity of hTERT gene promoter in MCF7 cell indicates its potential utility as a novel candidate for transcriptional targeting of breast cancer.