Rationally designed hydrolytically activated etoposide prodrugs, a novel strategy for the treatment of neuroblastoma

Cancer Lett. 2003 Jul 18;197(1-2):225-30. doi: 10.1016/s0304-3835(03)00106-x.

Abstract

Effective chemotherapy in neuroblastoma is limited by poor anti-tumor efficacy, systemic toxicity and the induction of drug resistance. Here, we provide further evidence that a hydrolytic activated prodrug design may overcome these problems. For this purpose, VP-16 was functionally blocked by a carbonate linker to generate two novel chemically stable prodrugs of VP-16, ProVP-16 I and II. We demonstrate profoundly different biological effects in vitro and in vivo of the prodrugs compared to parental VP-16. First, we established an up to >2 log higher in vitro toxicity of the two prodrugs compared to VP-16 on a panel of neuroblastoma cell lines. The highest increase of prodrug mediated cytotoxicity was observed in multi drug resistant cell lines. Second, in vivo studies showed a maximum tolerated dose (MTD) of ProVP-16 II (60 mg/kg), which was at least threefold higher than that of VP-16 (20 mg/kg). Tests of ProVP-16 II in a syngeneic NXS2 neuroblastoma model indicated that mice treated with this prodrug at 1/3 of the MTD was as effective as VP-16 parental compound used at the MTD in suppression of tumor growth. In summary, the etoposide prodrugs proved effective and less toxic and are therefore highly promising new anti-neuroblastoma compounds.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents, Phytogenic / pharmacology*
  • Biotransformation
  • Cell Survival / drug effects
  • DNA Primers / chemistry
  • Drug Design
  • Drug Resistance, Multiple
  • Drug Resistance, Neoplasm
  • Drug Screening Assays, Antitumor
  • Etoposide / pharmacology*
  • Female
  • Humans
  • Hydrolysis
  • Maximum Tolerated Dose
  • Mice
  • Neuroblastoma / drug therapy*
  • Neuroblastoma / metabolism
  • Neuroblastoma / pathology
  • Plasmids
  • Prodrugs / chemical synthesis
  • Prodrugs / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tumor Cells, Cultured

Substances

  • Antineoplastic Agents, Phytogenic
  • DNA Primers
  • Prodrugs
  • Etoposide