Poor intercellular transport and absence of enhanced antiproliferative activity after non-viral gene transfer of VP22-P53 or P53-VP22 fusions into p53 null cell lines in vitro or in vivo

✍ Scribed by David Zavaglia; Erh-Hsuan Lin; Mélanie Guidetti; Olivier Pluquet; Pierre Hainaut; Marie-Christine Favrot; Jean-luc Coll

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 239 KB
• Volume: 7
• Category: Article
• ISSN: 1099-498X
• DOI: 10.1002/jgm.741

✦ Synopsis

Abstract

Background

The herpes simplex virus type 1 (HSV‐1) VP22 protein has the property to mediate intercellular trafficking of heterologous proteins fused to its C‐ or N‐terminus. We have previously shown improved delivery and enhanced therapeutic effect in vitro and in vivo with a P27‐VP22 fusion protein. In this report, we were interested in studying the spread and biological activity of VP22 fused to the P53 tumor suppressor.

Methods

Expression of the VP22‐P53 and P53‐VP22 fusion proteins was shown by Western blot and intercellular spreading was monitored by immunofluorescence on transiently transfected cells. In vitro antiproliferative activity of wild‐type (wt) P53 and P53‐VP22 was assessed by proliferation assays and transactivating ability was studied by a reporter gene test and a gel‐shift assay. Antitumor activity was also tested in vivo by intratumoral injections of naked DNA in a model of subcutaneous tumors implanted in nude mice.

Results

Our results show that the C‐terminal fusion or the N‐terminal P53‐VP22 fusion proteins are not able to spread as efficiently as VP22. Moreover, we demonstrate that VP22‐P53 does not possess any transactivating ability. P53‐VP22 has an antiproliferative activity, but this activity is not superior to the one of P53 alone, in vitro or in vivo.

Conclusions

Our study indicates that a gene transfer strategy using VP22 cannot be considered as a universal system to improve the delivery of any protein. Copyright © 2005 John Wiley & Sons, Ltd.