Differential promoter activity in benign and malignant human cells of skin origin.

In order to develop systems to express mammalian proteins in human skin-derived cells, we tested 6 different viral and 1 eukaryoktic promoter (pCMV, pRSV, pSV, pMMTV, pPoly E, pPoly L, pHMT) for their ability to drive the expression to the chloramphenicol acetyltransferase (CAT) enzyme in different human skin-derived cells. DNA was transfected in human keratinocytes derived from normal foreskin and cervix in the HPV-negative cervical cancer line HT3 and in malignant melanoma cell lines (SK-Mel 23, SK-Mel 37) using a liposome-based technique or calcium precipitation. Transfection efficacy was controlled by cotransfection of a β-galactosidase gene construct. The enzymatic activity of the CAT-gene expression was determined of the cell extract prepared from the transfected cell with 14 C-labeled chloramphenicol. The CMV promoter was highly active in all skin- or mucosal-derived cells. In contrast to the strong CMV-promoter, was highly active in all the skin- or mucosal-derived cells. In contrast to the strong CMV-promoter, the RSV-. SV-, and HMT-promoter were less active and varied in dependence of the cell type. The pattern of the promoter activity differed between benign and transformed genital keratinocytes. Only The SV-promoter showed a comparable strong basal activity, which was restricted to the SK-Mel 37 cells, In conclusion, the promoter activity has to be tested for each cell type depending on the aims of the gene expression. [ABSTRACT FROM AUTHOR]