5-Fluorouracil-related enhancement of adenoviral infection is Coxsackievirus-adenovirus receptor independent and associated with morphological changes in lipid membranes.
OBJECTIVE
To evaluate the mechanism underlying the effects of 5-Fluorouracil (5-FU) on adenoviral infection.


METHODS
Low and high Coxsackievirus-Adenovirus Receptor (CAR) expressing human colon carcinoma cell lines were treated with 5-FU and two E1-deleted adenoviral constructs, one transferring GFP (Ad/CMV-GFP) the other bax (Ad/CEA-bax). The number of infected cells were monitored by GFP expression. To evaluate the effects of 5-FU in a receptor free system, Ad/GFP were encapsulated in liposomes and treated with 5-FU. Ad/GFP release was estimated with PCR and infection of 293 cells with the supernatant. Electron microscopy of the Ad5-GFP-liposome complex was made to investigate morphological changes of the liposomes after 5-FU.


RESULTS
Infection rates of all cell lines increased from 50% to 98% with emerging 5-FU concentrations. The enhanced viral uptake was independent of the CAR expression. Additionally, 5-FU treated liposomes released 2-2.5 times more adenoviruses. Furthermore, 5-FU-treated liposomes appeared irregular and porous-like.


CONCLUSIONS
Adenoviral uptake is enhanced in the presence of 5-FU irrespective of CAR and is associated with morphological changes in membranes making the combination of both a promising option in gene therapy.
Cabrele
Chiara
C
Department of Surgery, Clinic of the Regensburg University, Franz-Josef-Strauss-Allee 11, D-93053, Regensburg, Germany.
Vogel
Mandy
M
Piso
Pompiliu
P
Rentsch
Markus
M
Schröder
Josef
J
Jauch
Karl W
KW
Schlitt
Hans J
HJ
Beham
Alexander
A
D000257:Adenoviridae Infections / Q000188:drug therapy*; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D002460:Cell Line; D045744:Cell Line, Tumor; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D005472:Fluorouracil / Q000494:pharmacology*; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000737:chemistry*; D049452:Green Fluorescent Proteins / Q000737:chemistry; D006801:Humans; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry; D008566:Membranes / Q000737:chemistry; D011991:Receptors, Virus / Q000378:metabolism / Q000502:physiology*
D000964:Antimetabolites, Antineoplastic; C568771:CLMP protein, human; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D008055:Lipids; D008081:Liposomes; D011991:Receptors, Virus; D049452:Green Fluorescent Proteins; D005472:Fluorouracil