Design of a novel bicistronic expression vector with demonstration of a p16INK4-induced G(1)-S block(1).

Traditional eukaryotic gene expression systems have many shortcomings that make them unsuitable for the analysis of cytotoxic and growth-arrest genes. An intestinal alkaline phosphatase bicistronic expression vector was specifically designed to facilitate such studies. Intestinal alkaline phosphatase serves as a marker of cells that have been transfected and, therefore, must also be co-expressing the gene under study. Using flow cytometry, a trivariate analysis was performed on p16INK4-transfected U87 glioblastoma cells. An average G1-S block of 77.5% was demonstrated compared to controls despite a 1% transfection efficiency. This vector has universal applications, including: (a) analysis of cytotoxic and growth-inhibitory genes in transient assays; (b) 100% enrichement in gene expression studies, especially in low transfection efficiency experiments; and (c) facilitation of the study of cell cycle kinetics.