A humanized single-chain Fv fragment with high targeting potential against human malignant gliomas.
A humanized ONS-M21 antibody (hM21) against human medulloblastoma and glioma cells was engineered as a single-chain Fv fragment (scFv), and its ability to internalize into tumor cells was evaluated by conjugation with ricin A. The scFv of hM21 (schM21) was easily purified from E.coli by one-step affinity column chromatography. Purified schM21 bound to a medulloblastoma ONS-76 cell with almost equal antigen-binding activity of hM21-Fab fragment. Furthermore, the schM21-ricin A conjugate inhibited the growth of ONS-76 cells, but not that of antigen-negative hepatoma HuH-7 cells, suggesting that the schM21 can be internalized after binding to antigen-positive cells. Thus, schM21 could be expected to act as a novel carrier of diagnostic and therapeutic agents for brain tumors.
Ohtomo
T
T
Chugai Pharmaceutical Co., Ltd., Fuji Gotemba Research Laboratories, Shizuoka, Japan.
Kawata
H
H
Sekimori
Y
Y
Shimizu
K
K
Kishima
H
H
Moriuchi
S
S
Miyao
Y
Y
Akamatsu
K
K
Tsuchiya
M
M
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D000951:Antigens, Neoplasm / Q000276:immunology; D001666:Binding Sites, Antibody; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D007140:Immunoglobulin Fab Fragments; D007135:Immunoglobulin Variable Region; D000922:Immunotoxins / Q000633:toxicity*; D011994:Recombinant Proteins; D012276:Ricin / Q000633:toxicity*; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D000951:Antigens, Neoplasm; D007140:Immunoglobulin Fab Fragments; D007135:Immunoglobulin Variable Region; D000922:Immunotoxins; D011994:Recombinant Proteins; D012276:Ricin