Applying proteomic methodologies to analyze the effect of methionine restriction on proliferation of human gastric cancer SGC7901 cells.

Background: Methionine dependence is a feature unique to cancer cells, exhibited as inability to grow in a methionine-depleted environment supplemented with homocysteine, the immediate metabolic precursor of methionine. However, the molecular mechanisms by which methionine restriction inhibits cancer cells growth have not been elucidated. The effect of methionine restriction on the protein expression in gastric cancer cells was studied.

Methods: SGC7901 cells were treated with M-H+ medium for 5 days, which was followed by analysis of total cellular protein from cells by a combination of 2-DE and MS. Then the differential expressional levels of partially identified proteins were determined by Western blot analysis.

Results: The well-resolved, reproducible 2-DE patterns of SGC7901 cells cultured in M+H- or M-H+ medium were established. The 10 differential proteins between pairs of gastric cancer cells SGC7901 cultured either in M+H- medium or M-H+ medium, were identified by MALDI-TOF/TOF MS, and the differential expression levels of 2 identified proteins were confirmed.

Conclusion: These data will be valuable for further study of the molecular mechanisms by which methionine restriction induces cell cycle arrest and apoptosis in human gastric cancer.