Mitotic Spindle Directed Therapeutics for Early Stage Breast Carcinoma

摘要

For the proposed studies, we used a recombinant adenovirus that carries anti-stathmin ribozyme, Rz184, for inhibiting stathmin expression in breast cancer cells. We used a bicistronic expression vector, pAdCMV5- IRES-GFP, that contains an adenovirus origin of replication and 2.5 kilobases of human adenovirus type 5 (AdS) DNA for efficient homologous recombination. This vector also contains an internal ribosome entry site (IRES) element derived from the encephalomyocarditis virus that permits the translation of two open reading frames from the same messenger RNA. The IRES expression cassette of this vector is downstream from a unique cloning site to allow co-expression of a green fluorescent protein (GFP) selectable marker and the therapeutic gene i.e. the ribozyme. Both the selectable and the therapeutic gene are placed under the control of CMV5, a CMV promoter-enhancer modified for maximal expression. This arrangement allows high-level expression of the transgene and easy visualization and/or selection of transduced cells. We also generated a control adenovirus that carries GFP but not the ribozyme. The schematic illustrations of the adenoviral vectors are shown in Fig. 1. We tested the activity of these recombinant adenoviruses in JC and SC 115 in vitro murine models of breast cancer.