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

Oncogene. 1999 Apr 22;18(16):2579-88. doi: 10.1038/sj.onc.1202602.


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. Here we demonstrate that FTS also acts as a functional Ras antagonist in human pancreatic cell lines that express activated K-Ras (Panc-1 and MiaPaCa-2). In Panc-1 cells, FTS at a concentration of 25-100 microM 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / therapeutic use*
  • Antineoplastic Agents / toxicity
  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism
  • Dose-Response Relationship, Drug
  • Enzyme Activation
  • Epidermal Growth Factor / pharmacology
  • Farnesol / analogs & derivatives*
  • Farnesol / chemistry
  • Farnesol / therapeutic use
  • Farnesol / toxicity
  • Humans
  • Mice
  • Mice, Nude
  • Pancreatic Neoplasms / drug therapy*
  • Salicylates / chemistry
  • Salicylates / therapeutic use*
  • Salicylates / toxicity
  • Tumor Cells, Cultured
  • ras Proteins / antagonists & inhibitors*


  • Antineoplastic Agents
  • Salicylates
  • farnesylthiosalicylic acid
  • Farnesol
  • Epidermal Growth Factor
  • Calcium-Calmodulin-Dependent Protein Kinases
  • ras Proteins