[Comparative proteomic analysis of human large cell lung cancer cell line with high and low metastasis potentials].

OBJECTIVE: A comparative proteomic analysis on two human large cell lung cancer strains with high metastasis potential (L9981) and low metastasis potential (NL9980) were conducted.

METHODS: The total proteins of the two cell lines were separated by immobilized pH gradient (IPG )-based two-dimensional gel electrophoresis. The differential expression proteins of the two cell lines were analyzed using image analysis software. Thirteen differential expressed proteins were further identified using in-gel digestion with trypsin, of which peptide extracts were prepared for MALDI-TOF MS/MS analysis by Daltonics AutoFlex TOF-TOF LIFT Mass Spectrometer (Bruker). Protein identifications were searched in the NCBInr protein database using the Mascot search engine.

RESULTS: Protein image analysis indicated that 8 protein spots were observed only in L9981, not in NL9980; 8 protein spots were observed only in NL9980, not in L9981; 19 protein spots were detected in both L9981 and NL9980, of which 9 showed significantly higher volumes in L9981 than in NL9980 and 10 showed significantly higher volumes in NL9980 than in L9981. MS and biological informatics study found that the expressions of heat shock 70 kD protein 9B precursor, MTHSP75 and glutathione synthetas incerased in L9981 cells. However, a variant of P47 protein, immunoglobulin heavy chain variable region, enolasel, heat shock protein and eukaryotic translation initiation fact 3 were down-regulated in L9981 cells. Pyruvate kinase (PK) was only expressed in L9981 cells while WD-40 repeat protein was only expressed in NL9980 cells.

CONCLUSIONS: The metastatic lung cancer cell lines display different protein profiles compared to the non metastatic lung cancer cell lines. The identified proteins are likely to be associated with tumor metastasis, 4hich could serve as a basis for searching potential prognosis markers of lung cancer and elucidating the mechanisms of the metastasis of lung cancer.