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

Proc Natl Acad Sci U S A. 2013 Mar 19;110(12):E1083-91. doi: 10.1073/pnas.1217868110. Epub 2013 Mar 5.

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.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Animals
  • Antibodies, Neoplasm / pharmacology*
  • Antineoplastic Agents / pharmacology*
  • Carcinoma, Hepatocellular / drug therapy*
  • Carcinoma, Hepatocellular / metabolism
  • Carcinoma, Hepatocellular / pathology
  • G1 Phase Cell Cycle Checkpoints / drug effects
  • Glypicans / antagonists & inhibitors*
  • Glypicans / metabolism
  • Humans
  • Liver Neoplasms / drug therapy*
  • Liver Neoplasms / metabolism
  • Liver Neoplasms / pathology
  • Mice
  • Mice, Nude
  • Neoplasm Proteins / antagonists & inhibitors*
  • Neoplasm Proteins / metabolism
  • Neoplasm Transplantation
  • Single-Chain Antibodies / pharmacology*
  • Transplantation, Heterologous
  • Xenograft Model Antitumor Assays / methods

Substances

  • Antibodies, Neoplasm
  • Antineoplastic Agents
  • GPC3 protein, human
  • Glypicans
  • Neoplasm Proteins
  • Single-Chain Antibodies