Evaluation of the functional activity and specificity of the hSLPI gene promoter

BACKGROUND: One of the main problems of modern oncotherapy is the lack of selectivity of the antitumor drugs, leading to their systemic toxicity on the body. Targeted expression of therapeutic genes represents a new approach in cancer gene therapy. One of the ways to achieve the selectivity of action of the therapeutic genes towards tumor cells is the use of promoters that are active only in tumor cells, but not in normal cells.

AIM: To evaluate the functional activity and specificity of the promoter of the human secretory leukocyte protease inhibitor hSLPI.

MATERIALS AND METHODS: The promoter of the hSLPI gene was cloned into the promotorless vector pTurboGFP-PRL. The functional activity and specificity of the promoter were assessed by the expression of the mRNA of the TurboGFP reporter gene and the intensity of its luminescence in A549, MCF-7, HeLa tumor cells and WI-38 normal cells using real-time polymerase chain reaction with reverse transcription and fluorescence analysis, respectively.

RESULTS: Despite the literature data, the promoter of the hSLPIa gene demonstrated high transcriptional activity only against HeLa cervical cancer tumor cells. At the same time, in the cells of lung adenocarcinoma A549 and breast cancer MCF-7, as in normal WI-38 cells, a reduced level of promoter activity was observed.

CONCLUSION: The data obtained confirm the need for a preliminary assessment of the functional activity of tumor-specific promoters in relation to tumor and normal cells.