Targeting of c-Met and urokinase expressing human glioma cell lines by retrovirus vector displaying single-chain variable fragment antibody.
Amphotropic retroviruses with modified envelope displaying single-chain antibody fragment (scFv) directed against the c-Met receptor were recently generated and found to efficiently and selectively deliver genes into hepatocarcinoma cells. A large proportion of human gliomas also frequently overexpresses c-Met. We therefore explored the possibility of infecting glioma cells using such retroviruses bearing an scFv directed against c-Met. In one construct, a urokinase (uPA) cleavage site was inserted between the scFv and the envelope. We assessed the transduction by these chimeric viruses of a panel of seven human glioma cell lines that we characterized for their c-Met and uPA levels. We found that abundance of the c-Met receptor and viral infection were inversely correlated if we used the retrovirus displaying scFv directed against c-Met, suggesting that the chimeric virus binds preferentially to the c-Met receptor, resulting in virus sequestration. Addition of the uPA site between the scFv moiety and the envelope restored the infectivity of the virus, consistent with a "two-step" infection process: (1) virus binding to the c-Met receptor, (2) cleavage of the scFv moiety by uPA, enabling the virus to dissociate from c-Met and entry into the cells via the Pit-2 receptor. Our study has significant implications for the design of targeting strategies for gliomas expressing high levels of c-Met.
Solly
Sounkary K
SK
EMI 00-20, INSERM, Université Paris XI, Bat Grégory Pincus, Le Kremlin Bicêtre-cedex, France.
Nguyen
Tuan Huy
TH
Weber
Anne
A
Horellou
Philippe
P
D000906:Antibodies / Q000235:genetics / Q000276:immunology; D045744:Cell Line, Tumor; D018390:Gene Targeting; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism; D005910:Glioma / Q000235:genetics / Q000378:metabolism / Q000821:virology*; D006801:Humans; D007128:Immunoglobulin Fragments / Q000235:genetics*; D019859:Proto-Oncogene Proteins c-met / Q000378:metabolism*; D012190:Retroviridae / Q000235:genetics*; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism*
D000906:Antibodies; D007128:Immunoglobulin Fragments; D019859:Proto-Oncogene Proteins c-met; D014568:Urokinase-Type Plasminogen Activator