Identification of 14-3-3β in human gastric cancer cells and its potency as a diagnostic and prognostic biomarker

Gastric cancer is the second most common cause of cancer deaths worldwide and due to its poor prognosis, it is important that specific biomarkers are identified to enable its early detection. Through 2-D gel electrophoresis and MALDI-TOF-TOF-based proteomics approaches, we found that 14-3-3 beta, which was one of the proteins that were differentially expressed by 5-fluorouracil-treated gastric cancer SC-M1 cells, was upregulated in gastric cancer cells. 14-3-3 beta levels in tissues and serum were further validated in gastric cancer patients and controls. The results showed that 14-3-3 beta levels were elevated in tumor tissues (n=40) in comparison to normal tissues (n=40; p<0.01), and serum 14-3-3 beta levels in cancer patients (n=145) were also significantly higher than those in controls (n=63; p<0.0001). Elevated serum 14-3-3 beta levels highly correlated with the number of lymph node metastases, tumor size and a reduced survival rate. Moreover, overexpression of 14-3-3 beta enhanced the growth, invasiveness and migratory activities of tumor cells. Twenty-eight proteins involved in anti-apoptosis and tumor progression were also found to be differentially expressed in 14-3-3 beta-overexpressing gastric cancer cells. Overall, these results highlight the significance of 14-3-3 beta in gastric cancer cell progression and suggest that it has the potential to be used as a diagnostic and prognostic biomarker in gastric cancer.