Human recombinant arginase I (Co)-PEG5000 [HuArgI (Co)-PEG5000]-induced arginine depletion is selectively cytotoxic to human glioblastoma cells

Oula Khoury, Noura Ghazale, Everett Stone, Mirvat El-Sibai, Arthur E. Frankel, Ralph J. Abi-Habib

Research output: Contribution to journalArticlepeer-review

42 Scopus citations


In this study, we attempt to target Arginine auxotrophy in glioblastoma multiforme (GBM) cells using a pegylated recombinant human Arginase I cobalt [HuArgI (Co)-PEG5000]. We tested and characterized the activity of HuArgI (Co)-PEG5000 on a panel of 9 GBM cell lines and on human fetal glial cells (SVG-p12). HuArgI (Co)-PEG5000 was cytotoxic to all GBM cells tested. SVG-p12 cells were not sensitive demonstrating the selective cytotoxicity of HuArgI (Co)-PEG5000-induced arginine deprivation. Addition of l-citrulline led to the rescue of 6 GBM cell lines but only at concentrations of 11.4 mM, reflecting the extent of arginine auxotrophy in GBM. The ability of l-citrulline to rescue cells was dependent on the expression of argininosuccinate synthetase-1 (ASS1) with the cells that were not rescued by l-citrulline being negative for ASS1 expression. Knocking-down ASS1 reversed the ability of l-citrulline to rescue GBM cells, further illustrating the dependence of arginine auxotrophy on ASS1 expression. Inhibition of autophagy increased cell sensitivity to HuArgI (Co)-PEG5000 indicating that, following arginine deprivation, autophagy plays a protective role in GBM cells. Analysis of the type of cell death revealed a lack of AnnexinV staining and caspase activation in HuArgI (Co)-PEG5000-treated cells, indicating that arginine deprivation induces caspase-independent, non-apoptotic cell death in GBM. We have shown that GBM cells are auxotrophic for arginine and can be selectively targeted using HuArgI (Co)-PEG5000-induced arginine depletion, thus demonstrating that l-Arginine deprivation is a potent and selective potential treatment for GBM.

Original languageEnglish (US)
Pages (from-to)75-85
Number of pages11
JournalJournal of Neuro-Oncology
Issue number1
StatePublished - Mar 2015


  • Arginine
  • Autophagy
  • GBM
  • HuArgI (Co)-PEG5000

ASJC Scopus subject areas

  • Oncology
  • Neurology
  • Clinical Neurology
  • Cancer Research


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