[Proteomic identification and comparison of differentiation-related proteins in gastric carcinoma cell lines]

To investigate the differentiation-related proteins in human gastric carcinoma cell lines by comparative proteomics.

The holoproteins of human gastric carcinoma cell lines MKN28, SGC7901 and BGC823 were measured by two-dimensional gel electrophoresis and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Some proteins identified by proteomics were tested by Western blot in the cell strains and tissues of gastric carcinoma.

14 differential protein spots were found in the 3 gastric carcinoma cell lines, among them 8 spots were identified by MALDI-TOF-MS. These proteins were probably thioredoxin peroxidase, glyceraldehyde-3-phosphate dehydrogenase (GAPD), beta-tubulin polypeptide, hypothetical protein, zinc finger protein (ZNF) 139, protein-tyrosine kinase, calreticulin precursor, and tropomyosin, proteins related with biological behavior of gastric carcinoma cells such as signal transduction, cellular homeostasis, glycolysis, antioxidation action, multidrug resistance(MDR), etc. The expressions of those proteins in gastric cancer cells and tissues identified by Western blot were consistent with the results obtained by proteomics.

Differential proteins are found in 3 human gastric carcinoma cell lines, mainly, proteins related with cell signaling, maintenance of homeostasis, glycolysis, metabolism of anti-cancer drug and anti-oxidative injury, etc.