Identification of tyrosine-phosphorylated proteins associated with lung cancer metastasis using label-free quantitative analyses

J Proteome Res. 2010 Aug 6;9(8):4102-12. doi: 10.1021/pr1006153.


Lung cancer is a lethal disease, and early metastasis is the major cause of treatment failure and cancer-related death. Tyrosine phosphorylated (P-Tyr) proteins are involved in the invasive and metastatic behavior of lung cancer; however, only a limited number of targets were identified. We attempt to characterize P-Tyr proteins and events involved in the metastatic process. In a previous work, we have developed a strategy for identification of protein phosphorylation. Here, this strategy was used to characterize the tyrosine phosphoproteome of lung cancer cells that have different invasive abilities (CL1-0 vs. CL1-5). Using our analytical strategy, we report the identification of 335 P-Tyr sites from 276 phosphoproteins. Label-free quantitative analysis revealed that 36 P-Tyr peptides showed altered levels between CL1-0 and CL1-5 cells. From this list of sites, we extracted two novel consensus sequences and four known motifs for specific kinases and phosphatases including EGFR, Src, JAK2, and TC-PTP. Protein-protein interaction network analysis of the altered P-Tyr proteins illustrated that 11 proteins were linked to a network containing EGFR, c-Src, c-Myc, and STAT, which is known to be related to lung cancer metastasis. Among these 11 proteins, 7 P-Tyr proteins have not been previously reported to be associated with lung cancer metastasis and are of greatest interest for further study. The characterized tyrosine phosphoproteome and altered P-Tyr targets may provide a better comprehensive understanding of the mechanisms of lung cancer invasion/metastasis and discover potential therapies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaline Phosphatase
  • Blotting, Western
  • Cell Line, Tumor
  • Chromatography, Liquid
  • Computational Biology
  • ErbB Receptors / metabolism
  • Humans
  • Immunoprecipitation
  • Janus Kinase 2 / metabolism
  • Lung Neoplasms / pathology*
  • Neoplasm Metastasis / diagnosis*
  • Phosphoproteins / analysis*
  • Phosphoproteins / metabolism*
  • Phosphorylation
  • Protein Tyrosine Phosphatase, Non-Receptor Type 2 / metabolism
  • Proteomics / methods*
  • Tandem Mass Spectrometry
  • Titanium
  • Tyrosine / metabolism*
  • src-Family Kinases / metabolism


  • Phosphoproteins
  • titanium dioxide
  • Tyrosine
  • Titanium
  • EGFR protein, human
  • ErbB Receptors
  • JAK2 protein, human
  • Janus Kinase 2
  • src-Family Kinases
  • Alkaline Phosphatase
  • PTPN2 protein, human
  • Protein Tyrosine Phosphatase, Non-Receptor Type 2