Figure 1.

Schematic representation of transcriptionally targeted gene expression. Tissue- or cancer-specific promoter-driven reporter or therapeutic gene is incorporated into a gene delivery vector (depicted as recombinant adenovirus here). Gene transfer can occur in both targeted cancer cells and non-targeted normal cells. However, trans-gene expression can only occur in cancer cells due to the presence of transcription factors competent to mediate expression of the specific promoter. Red squares denote the endogenous gene product expressed from the specific promoter. The swirls denote the reporter/therapeutic gene product.