Cell cycle regulated promoters for the targeting of tumor endothelium.

Targeting of gene expression to tumors is one of the major challenges in cancer gene therapy. In this context both vector targeting and cell-specific transcription are of particular importance. Promotors or enhancers, which are potentially useful for gene therapy, have been shown to be selectively or preferentially active in certain cell types [1] or tumors [2–4] or to be inducible by drugs [5] or radiation [6]. We have designed a new concept, in which cell cycle regulated promoters are used to express therapeutic genes specifically in proliferating cells [7].