A new functional Ras antagonist inhibits human pancreatic tumor growth in nude mice

Boaz Weisz, Klaudia Giehl, Mali Gana-Weisz, Yaakov Egozi, Gilad Ben-Baruch, Daniela Marciano, Peter Gierschik, Yoel Kloog

Research output: Contribution to journalArticlepeer-review


Constitutively active Ras proteins, their regulatory components, and overexpressed tyrosine kinase receptors that activate Ras, are frequently associated with cell transformation in human tumors. This suggests that functional Ras antagonists may have anti-tumor activity. Studies in rodent fibroblasts have shown that S-trans, transfarnesylthiosalicylic acid (FTS) acts as a rather specific nontoxic Ras antagonist, dislodging Ras from its membrane anchorage domains and accelerating its degradation. FTS is not a farnesyltransferase inhibitor, and does not affect Ras maturation. Mere we demonstrate that FTS also acts as a functional Ras antagonist in human pancreatic cell lines that express activated K-Pas (Panc-1 and MiaPaCa-2). In Panc-1 cells, FTS at a concentration of 25-100 μM reduced the amount of Ras in a dose-dependent manner and interfered with serum-dependent and epidermal growth factor-stimulated ERK activation, thus inhibiting both anchorage-dependent and anchorage-independent growth of Panc-1 cells in vitro. FTS also inhibited tumor growth in Panc-1 xenografted nude mice, apparently without systemic toxicity. Daily FTS treatment (5 mg/kg intraperitoneally) in mice with tumors (mean volume 0.07 cm3) markedly decreased tumor growth (after treatment for 18 days, tumor volume had increased by only 23 ± 30-fold in the FTS-treated group and by 127 ± 66-fold in controls). These findings suggest that FTS represents a new class of functional Ras antagonists with potential therapeutic value.

Original languageEnglish
Pages (from-to)2579-2588
Number of pages10
Issue number16
StatePublished - 22 Apr 1999


  • EGF
  • FTS
  • Human pancreatic tumor
  • MAPK
  • Panc-1
  • Ras antagonists
  • Ras oncogenes


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