High thermal stability is essential for tumor targeting of antibody fragments: Engineering of a humanized anti-epithelial glycoprotein-2 (epithelial cell adhesion molecule) single-chain Fv fragment

Citation
J. Willuda et al., High thermal stability is essential for tumor targeting of antibody fragments: Engineering of a humanized anti-epithelial glycoprotein-2 (epithelial cell adhesion molecule) single-chain Fv fragment, CANCER RES, 59(22), 1999, pp. 5758-5767
Citations number
54
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Oncology,"Onconogenesis & Cancer Research
Journal title
CANCER RESEARCH
ISSN journal
0008-5472 → ACNP
Volume
59
Issue
22
Year of publication
1999
Pages
5758 - 5767
Database
ISI
SICI code
0008-5472(19991115)59:22<5758:HTSIEF>2.0.ZU;2-Z
Abstract
The epithelial glycoprotein-2 is abundantly expressed on many solid tumors and is a suitable target for antibody-based therapy. In the present study, an antiepithelial glycoprotein-2 single-chain Fv (scFv) was derived from th e hybridoma MOC31 by phage display, Despite its high affinity (K-D = 3.9 x 10(-9) M), however, this antibody fragment failed to significantly enrich a t lung tumor xenografts in mice, mostly because of its insufficient thermal stability. To overcome this Limitation, the antigen-binding residues of th e MOC31 scFv fragment were grafted onto the framework of the highly stable and well-folding anti-c-erbB2 scFv 4D5, Further modification of the resulti ng 4D5 MOC-A, which was performed by transferring eight additional residues of the heavy chain variable domain core of the parent MOC31 antibody, prod uced 4D5 MOC-B, resulting in increased serum stability at 37 degrees C and also significantly improved expression behavior while retaining the antigen specificity and affinity of the parent MOC31 scFv, In mice, the scFv 4D5 M OC-B, which was radiolabeled with (99m)technetium using a new histidine-tag specific labeling method (Waibel et ol,, Nature Biotechnol., 17: 897-901, 1999), showed favorable blood clearance and efficient enriches at lung tumo r xenografts, with a tumor:blood ratio of 5.25 and a total dose of 1.47% in jected dose per gram after 24 h, Biophysical properties such as high therma l stability are thus decisive for whether these molecules are useful ill vi vo and our approach may provide a general strategy to solve this problem. T his is also the first report of using a humanized anti-EGP-2 scFv in vivo f or targeting solid tumors, which is a promising targeting moiety for the di agnostics and therapy of EGP-2-positive tumors in patients,