1B50-1, a mAb raised against recurrent tumor cells, targets liver tumor-initiating cells by binding to the calcium channel α2δ1 subunit

Cancer Cell. 2013 Apr 15;23(4):541-56. doi: 10.1016/j.ccr.2013.02.025.

Abstract

The identification and targeted therapy of cells involved in hepatocellular carcinoma (HCC) recurrence remain challenging. Here, we generated a monoclonal antibody against recurrent HCC, 1B50-1, that bound the isoform 5 of the α2δ1 subunit of voltage-gated calcium channels and identified a subset of tumor-initiating cells (TICs) with stem cell-like properties. A surgical margin with cells detected by 1B50-1 predicted rapid recurrence. Furthermore, 1B50-1 had a therapeutic effect on HCC engraftments by eliminating TICs. Finally, α2δ1 knockdown reduced self-renewal and tumor formation capacities and induced apoptosis of TICs, whereas its overexpression led to enhanced sphere formation, which is regulated by calcium influx. Thus, α2δ1 is a functional liver TIC marker, and its inhibitors may serve as potential anti-HCC drugs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / immunology*
  • Antibodies, Monoclonal / metabolism
  • Apoptosis / drug effects
  • Calcium Channels / metabolism*
  • Carcinoma, Hepatocellular / immunology*
  • Carcinoma, Hepatocellular / metabolism
  • Carcinoma, Hepatocellular / pathology
  • Carcinoma, Hepatocellular / therapy
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Humans
  • Liver Neoplasms / immunology*
  • Liver Neoplasms / metabolism
  • Liver Neoplasms / pathology
  • Liver Neoplasms / therapy
  • Mice
  • Mice, Inbred NOD
  • Mice, SCID
  • Neoplasm Recurrence, Local / immunology*
  • Neoplasm Recurrence, Local / metabolism
  • Neoplasm Recurrence, Local / pathology
  • Neoplastic Stem Cells / immunology*
  • Neoplastic Stem Cells / metabolism
  • Neoplastic Stem Cells / pathology

Substances

  • Antibodies, Monoclonal
  • Calcium Channels