Biochemical and cellular effects of c-Src kinase-selective pyrido[2, 3-d]pyrimidine tyrosine kinase inhibitors

Biochem Pharmacol. 2000 Oct 1;60(7):885-98. doi: 10.1016/s0006-2952(00)00405-6.


Increased expression or activity of c-Src tyrosine kinase has been associated with the transformed phenotype in tumor cells and with progression of neoplastic disease. A number of pyrido[2, 3-d]pyrimidines have been characterized biochemically and in cells as part of an assessment of their potential as anti-tumor agents. The compounds were ATP-competitive inhibitors of c-Src kinase with IC(50) values < 10 nM and from 6 to >100-fold selectivity for c-Src tyrosine kinase relative to basic fibroblast growth factor receptor (bFGFr) tyrosine kinase, platelet-derived growth factor receptor (PDGFr) tyrosine kinase, and epidermal growth factor receptor (EGFr) tyrosine kinase. The compounds yielded IC(50) values < 5 nM against Lck. Human colon tumor cell growth in culture was inhibited, as was colony formation in soft agar at concentrations < 1 microM. Phosphorylation of the c-Src cellular substrates paxillin, p130(cas), and Stat3 was also inhibited at concentrations < 1 microM. Autophosphorylation of EGFr tyrosine kinase or PDGFr tyrosine kinase was not inhibited by c-Src inhibitors, thus showing the selective nature of the compounds in cells. In a mitogenesis assay measuring thymidine incorporation stimulated by specific mitogens, the c-Src tyrosine kinase inhibitors reduced incorporated thymidine in a manner consistent with previously reported roles of c-Src in mitogenic signaling. Progression through the cell cycle was inhibited at G(2)/M in human colon tumor cells treated with two of the c-Src-selective compounds, which is also consistent with earlier reports describing a requirement for active c-Src tyrosine kinase for G(2) to M phase progression. The compounds described here are selective inhibitors of c-Src tyrosine kinase and have antiproliferative effects in tumor cells consistent with inhibition of c-Src.

MeSH terms

  • CSK Tyrosine-Protein Kinase
  • Cell Cycle / drug effects
  • Cell Division / drug effects
  • DNA / biosynthesis
  • DNA / drug effects
  • Enzyme Inhibitors / pharmacology*
  • HT29 Cells
  • Humans
  • Phenotype
  • Phosphorylation / drug effects
  • Protein-Tyrosine Kinases / antagonists & inhibitors*
  • Protein-Tyrosine Kinases / metabolism
  • Pyrimidines / chemistry
  • Pyrimidines / pharmacology*
  • Thymidine / metabolism
  • Tumor Cells, Cultured
  • src-Family Kinases


  • Enzyme Inhibitors
  • PD 173074
  • Pyrimidines
  • DNA
  • Protein-Tyrosine Kinases
  • CSK Tyrosine-Protein Kinase
  • src-Family Kinases
  • CSK protein, human
  • Thymidine