Targeting of adenovirus vectors carrying a tumor cell-specific peptide: in vitro and in vivo studies

Abstract

Previously, we have identified a tumor cell-specific peptide, HEW, by panning of phage display libraries on the human colorectal cancer cell line WiDr. In this report we demonstrate that this peptide can modify the infection properties of adenovirus vectors. Increased infectivity of replication-deficient adenovirus 5 vectors in WiDr cells was observed upon genetic insertion of the HEW peptide in the HI loop of the fiber knob. Moreover, whereas the coxsackie and adenovirus receptor (CAR)-ablating fiber mutation S408E abolished apparent infection in CAR-positive WiDr cells, the insertion of HEW completely restored infectivity toward these cells in vitro. To assess whether the de-and re-targeted infection profile was maintained in vivo, the fiber-modified adenovirus vectors were injected intratumorally or intravenously in WiDr tumor-bearing Swiss nu/nu mice. No significant differences in efficiency of infection could be observed suggesting alternative viral uptake mechanisms in vivo. Next, we have included the fiber shaft mutation S* in our studies, which was described to confer a de-targeted phenotype in vivo. Reduced gene transfer due to the S* mutation both in vitro and in vivo could be confirmed. Insertion of HEW in the HI knob loop of shaft-mutated fiber, however, did not rescue infectivity in target cells neither in vitro nor in vivo. We demonstrate the efficient ligand-mediated re-targeting of adenoviral vector infection to the human cancer cell line WiDr. The lack of apparent re-targeting in the in vivo situation is described.

Improved systemic antitumor therapy with oncolytic adenoviruses by replacing the fiber shaft HSG-binding domain with RGD

“…6 Alternatively, the mutation of the heparan sulfate glycosaminoglycan (HSG) putative-binding site KKTK of the Ad5 fiber shaft domain detargets liver transduction, probably because of affectation of the bending or structure of the fiber. 2,7,8 On the other hand, the HI-loop of the fiber knob domain has been used to accommodate a broad range of tumor-selective peptides for tumor targeting [9][10][11] Among all peptides incorporated into the HI loop, the CDCRGDCFC motif (known as RGD-4C) has been broadly used and confers on Ad5 a CAR-independent entry mechanism by using aV-b3 and aV-b5 integrins as primary receptors. 12,13 As integrins are a large family of adhesive receptors involved in the spread and adhesion of tumor cells, the RGD-4C motif leads to the enhancement of tumor cell infectivity and oncolytic effect both in vitro and in vivo.…”

Replacement of Adenovirus Type 5 Fiber Shaft Heparan Sulfate Proteoglycan-Binding Domain with RGD for Improved Tumor Infectivity and Targeting

“…In vitro competition analysis with heparin supports a major role of HSPGs in Ad5 entry in the absence of CAR (Smith et al, 2002(Smith et al, , 2003bBayo-Puxan et al, 2006). The KKTK domain contributes to Ad5 liver transduction in vivo, as its mutation to GATK or GAGA detargets liver transduction (Smith et al, 2003a,b;Nicol et al, 2004;Bayo-Puxan et al, 2006;Kritz et al, 2007;Rittner et al, 2007).…”

Adenovirus-mediated Double Suicide Gene Selectively Kills Gastric Cancer Cells

“…The application of a single enzyme/pro-drug system barely achieves the purpose of cancer cure, and multiple suicide gene combinations are some of the ways to improve the effect of such systems (Rittner et al, 2007). Therefore, the current study used the pAdEasy system to construct a CD/TK double suicide fusion recombinant adenovirus.…”