Dataset Information

Therapeutically targeting glypican-3 via a conformation-specific single-domain antibody in hepatocellular carcinoma.

ABSTRACT: Glypican-3 (GPC3) has emerged as a candidate therapeutic target in hepatocellular carcinoma (HCC), but the oncogenic role of GPC3 in HCC is poorly understood. Here, we report a human heavy-chain variable domain antibody, HN3, with high affinity (Kd = 0.6 nM) for cell-surface-associated GPC3 molecules. The human antibody recognized a conformational epitope that requires both the amino and carboxy terminal domains of GPC3. HN3 inhibited proliferation of GPC3-positive cells and exhibited significant inhibition of HCC xenograft tumor growth in nude mice. The underlying mechanism of HN3 action may involve cell-cycle arrest at G1 phase through Yes-associated protein signaling. This study suggests a previously unrecognized mechanism for GPC3-targeted cancer therapy.

SUBMITTER: Feng M

PROVIDER: S-EPMC3607002 | biostudies-literature | 2013 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Therapeutically targeting glypican-3 via a conformation-specific single-domain antibody in hepatocellular carcinoma.

Feng Mingqian M Gao Wei W Wang Ruoqi R Chen Weizao W Man Yan-Gao YG Figg William Douglas WD Wang Xin Wei XW Dimitrov Dimiter S DS Ho Mitchell M

Proceedings of the National Academy of Sciences of the United States of America 20130305 12

Glypican-3 (GPC3) has emerged as a candidate therapeutic target in hepatocellular carcinoma (HCC), but the oncogenic role of GPC3 in HCC is poorly understood. Here, we report a human heavy-chain variable domain antibody, HN3, with high affinity (Kd = 0.6 nM) for cell-surface-associated GPC3 molecules. The human antibody recognized a conformational epitope that requires both the amino and carboxy terminal domains of GPC3. HN3 inhibited proliferation of GPC3-positive cells and exhibited significan ...[more]

PMID: 23471984

Similar Datasets

Project description:UnlabelledHepatocellular carcinoma (HCC) is an increasingly lethal malignancy for which management is critically dependent on accurate imaging. Glypican-3 (GPC3) is a cell surface receptor overexpressed in most HCCs and provides a unique target for molecular diagnostics. The use of monoclonal antibodies (mAbs) that target GPC3 (αGPC3) in PET imaging has shown promise but comes with inherent limitations associated with mAbs such as long circulation times. This study used (89)Zr-conjugated F(ab')2 fragments directed against GPC3 ((89)Zr-αGPC3-F(ab')2) to evaluate the feasibility of the fragments as a diagnostic immuno-PET imaging probe.MethodsImmobilized ficin was used to digest αGPC3, creating αGPC3-F(ab')2 fragments subsequently conjugated to (89)Zr. In vivo biodistribution and PET studies were performed on GPC3-expressing HepG2 and GPC3-nonexpressing RH7777 orthotopic xenografts.ResultsReliable αGPC3-F(ab')2 production via immobilized ficin digestion was verified by high-performance liquid chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis. (89)Zr-αGPC3-F(ab')2 demonstrated F(ab')2-dependent, antigen-specific cell binding. HepG2 tumor uptake was higher than any other tissue, peaking at 100 ± 21 percentage injected dose per gram (%ID/g) 24 h after injection, a value 33- to 38-fold higher than GPC3-nonexpressing RH7777 tumors. The blood half-life of the (89)Zr-αGPC3-F(ab')2 conjugate was approximately 11 h, compared with approximately 115 h for historic mAb controls. This shorter half-life enabled clear tumor visualization on PET 4 h after administration, with a resultant peak tumor-to-liver contrast ratio of 23.3. Blocking antigen-expressing tumors with an excess of nonradiolabeled αGPC3 resulted in decreased tumor uptake similar to native liver. The kidneys exhibited high tissue uptake, peaking at 24 h with 83 ± 12 %ID/g. HepG2 tumors ranging from 1.5 to 7 mm were clearly visible on PET, whereas larger RH7777 tumors displayed signal lower than background liver tissue.ConclusionThis study demonstrates the feasibility of using (89)Zr-αGPC3-F(ab')2 for intrahepatic tumor localization with small-animal PET. Faster blood clearance and lower background liver uptake enable excellent signal-to-noise ratios at early time points. Increased renal uptake is similar to that as has been seen with clinical radioactive peptide imaging. (89)Zr-αGPC3-F(ab')2 addresses some of the shortcomings of whole-antibody immuno-PET probes. Further optimization is warranted to maximize probe sensitivity and specificity in the process of clinical translation.

Dataset Information

Therapeutically targeting glypican-3 via a conformation-specific single-domain antibody in hepatocellular carcinoma.

Publications

Therapeutically targeting glypican-3 via a conformation-specific single-domain antibody in hepatocellular carcinoma.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets