Abstract

The goal of our team is to develop a sensitive system to specifically kill liver cancer cells via genetic

circuits, by using the combination of liver cancer-specific promoters and miRNAs.

The expression of Gal4-VP16 fusion protein was under the control of liver cancer cells-specific AFP,

hTERT or ZEB1-AS1 promoters.

The Gal4-VP16 in turn drives the HSV-thymidine kinase (HSV-TK) expression by binding to nine tandem

UAS elements in the promoter.

Furthermore, the expression of Gal80, a Gal4 inhibitor, is controlled under a CMV promoter as well as a

cluster of miRNA93/miRNA-362-5p/miRNA-221 binding sites at the 3’-end.

As miRNA93/miRNA-362-5p/miRNA-221 are liver cancer cells-specific miRNAs, the expression of Gal80

is significantly suppressed in the liver cancer cells compared with normal cells.

As a result, the nontoxic ganciclovir is converted by HSV-TK to a cell-killing drug in the liver cancer cells,

but not normal cells.