GTMB 7 - Gene Therapy & Molecular Biology

Gene Therapy and Molecular Biology Vol 7, page 79II. Preclinical studiesAntiproliferative gene therapy strategies designed forthe treatment of experimental cardiovascular diseaseinclude the following: 1) inactivation of positive cell cycleregulators (e. g., CDK/cyclins, protooncogenes, E2F,growth factors) by antisense approaches, ribozymes, andtranscription factor ‘decoy’ strategies (Figure 4), 2)overexpression of negative regulators of cell growth (e. g.,CKIs, p53, pRb, GAX, and GATA-6), and 3)overexpression of transdominant negative mutants ofpositive cell cycle regulators (e. g., Ras, mitogen-activatedprotein kinases).Table 2: Gene therapy clinical trials for vascular proliferative disease based on cytostatic strategies.Trial Design Strategy Disease Outcome Refs.PREVENT IPREVENT IIITALICSPREVENT:ITALICS:Randomized,double-blinded,single centerE2F decoy ODNex vivotransfectionof vein graftAutologousvein graftfailure afterperipheralartery bypass70-74% decreases inthe level of positivecell cycle regulatorsexpressed by VSMCsin the vein, andreduction in primarygraft failureMann etal, 1999RandomizedE2F decoy ODN Autologous vein Larger patency and Dzau et al,multicenter,ex vivograft failure after inhibition neointimal 2002double-blinded, transfection coronary artery thickeningplacebo-controlled of vein graft bypassRandomized, c-myc antisense In-stentNo reduction inKutryk etplacebo-controlled ODN delivery coronaryangiographical, 2002after stent restenosisrestenosis rateimplantationProject of ex-vivo vein graft engineering via transfectionInvestigation by the thoraxcenter of antisense DNA using local delivery and IVUS after coronary stentingFigure 4. Targeted gene inactivation by means of gene therapy strategies. Decoy approach by delivering a double-stranded ODNcorresponding to the optimum DNA recognition sequence of the transcription factor of interest (TF) leads to attenuation of its interactionwith the authentic cis-elements in cellular target genes, thus resulting in reduced gene transcription. Ribozymes inactivate the gene ofinterest by degrading their transcript. Antisense ODNs hybridize in a complementary fashion and stoicheometrically with the targetmRNA, thus causing blockade of translation or synthesis of a truncated (inactive) protein.79