Cloning of human NKX3. 1 gene promoter and assay of its promoter activity in different tumor cell lines / 中国病理生理杂志

ABSTRACT

AIM: To study the basic mechanism of transcriptional regulation, NKX3.1 gene promoter was cloned and its promoter activities in prostate cancer cell lines and other cancer cell lines were tested. METHODS: 1.04 kb - promoter fragment of NKX3. 1 gene was obtained by PCR and cloned into pGL3 - basic and pEGFP - 1 that are promoter - less reporter vectors to examine its promoter activity driving the reporter gene transcription. The promoter activity was determined by dual -luciferase reporter assay and the expression of GFP reporter observed under fluorescence micro scope. RESULTS: The sequence of the cloned 1.04 kb promoter proved to be correct by DNA sequencing. The dual - lu ciferase reporter assay (M1/M2) showed that the promoter activity in LNCaP cell transfected with pGL3 - 1.04 kb promoter was about 1.5 - fold higher than that of pGL3 - control transfection and 50 - fold higher than that of pGL3 - basic transfec tion. To investigate the 1.04 kb - promoter activity in different tumor cell lines, the constructed pGL3 - 1.04 kb promoter and pEGFP - 1.04 kb promoter were transfected into several cell lines, respectively. The results showed that the activity of 1.04 kb promoterin LNCaP was highest among the tested cell lines. Multiple consensus sequence elements have been iden tified within the 1.04 kb fragment using TRANSFAC database. Further experiments will be done to determine their founc tions. CONCLUSION: Cloned 1.04 kb fragment upstream of NKX3.1 gene presented a strong promoter activity and its activity was highest in LNCaP cell among the tested tumor cell lines.