Bystander killing of tumour cells by antibody-targeted enzymatic activation of a glucuronide prodrug

Br J Cancer. 1999 Mar;79(9-10):1378-85. doi: 10.1038/sj.bjc.6690221.


RHI-betaG-PEG, formed by linking poly(ethylene glycol)-modified beta-glucuronidase to Mab RH1, was employed to examine bystander killing of antigen-negative N1S1 rat hepatoma cells by activation of a glucuronide prodrug (BHAMG) of p-hydroxyaniline mustard (pHAM) at antigen-positive AS-30D rat hepatoma cells. Sequential treatment of cells with 10 microg ml(-1) RH1-betaG-PEG and 20 microM BHAMG was not toxic to N1S1 cells but killed 99% of AS-30D cells. Over 98% of N1S1 cells, however, were killed in mixed populations containing as few as 2% AS-30D cells after identical treatment, demonstrating an in vitro bystander effect. Subcutaneous injection of AS-30D and N1S1 cells in BALB/c nu/nu mice produced solid tumours containing both cells. Uptake of radiolabelled RH1-betaG-PEG in solid AS-30D and mixed AS-30D/N1S1 tumours was 11.6 and 9.3 times greater than a control antibody conjugate 120 h after i.v. injection. Intravenous treatment with RH1-betaG-PEG and BHAMG cured seven of seven nude mice bearing solid s.c. AS-30D tumours and significantly delayed, compared with control conjugate and prodrug treatment, the growth of mixed N1S1/AS-30D tumours with one cure, showing that targeted activation of BHAMG kills bystander tumour cells in vivo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aniline Mustard / analogs & derivatives*
  • Aniline Mustard / metabolism
  • Aniline Mustard / therapeutic use
  • Animals
  • Antibodies, Monoclonal / metabolism
  • Antibodies, Monoclonal / therapeutic use
  • Antineoplastic Agents, Alkylating / metabolism
  • Antineoplastic Agents, Alkylating / therapeutic use*
  • Diffusion
  • Drug Screening Assays, Antitumor
  • Glucuronidase / metabolism
  • Glucuronidase / therapeutic use*
  • Immunohistochemistry
  • Immunotoxins / metabolism
  • Immunotoxins / therapeutic use*
  • Liver Neoplasms, Experimental / metabolism
  • Liver Neoplasms, Experimental / therapy
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Polyethylene Glycols / metabolism
  • Polyethylene Glycols / therapeutic use*
  • Prodrugs / metabolism
  • Prodrugs / therapeutic use*
  • Rats
  • Rats, Sprague-Dawley
  • Time Factors
  • Tumor Cells, Cultured


  • Antibodies, Monoclonal
  • Antineoplastic Agents, Alkylating
  • Immunotoxins
  • Prodrugs
  • hydroxyaniline mustard
  • Polyethylene Glycols
  • Aniline Mustard
  • Glucuronidase