Background: Recently, researchers have tried to predict patient prognosis using biomarker expression in cancer patients. The aim of this study was to develop a nomogram predicting the 5-year recurrence-free probability (RFP) of gastric cancer patients using prognostic biomarker gene expression. Methods: We enrolled 360 patients in the training data set to develop the predictive model and nomogram. We analyzed the patients' general variables and the gene expression levels of 10 prognostic biomarker candidates between the nonrecurrence and recurrence groups. We also performed external validation using 420 patients from the validation data set. Results: The final nomogram was composed of age, sex, and the expression levels of CAPZA, PPase, OCT-1, PRDX4, gamma-enolase, and c-Myc. The five-year RFPs were 89%, 75%, 54% and 32% for the patients in the low-risk, intermediate-risk, high-risk and very-high-risk groups in the development cohort, respectively. In the external validation cohort, the 5-year RFPs were 89%, 75%, 63% and 60%, respectively. The areas under the curve were 0.718 (95% CI, 0.65e0.78) and 0.640 (95% CI, 0.57e0.70) for the training and validation data sets, respectively. The RFP Kaplan-Meier curves were significantly different among the 4 groups in the training and validation data sets (p < 0.0001). Conclusion: This newly developed nomogram using gene expression can predict the 5-year RFP for gastric cancer patients after surgical treatment. We hope that this nomogram will help in the therapeutic decision between endoscopic treatment and gastrectomy.

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PurposeEnolase is a cytoplasmic enzyme that catalyzes the conversion of 2-phosphoglycerate to phosphoenolpyruvate in the glycolytic pathway. The aim of this study was to investigate whether the overexpression of neuron-specific enolase (NSE) can serve as a prognostic factor in patients with gastric cancer (GC).Materials and MethodsTo assess its prognostic value in GC, NSE expression was measured by immunohistochemistry in a clinically annotated tissue microarray comprising of 327 human GC specimens. Cytoplasmic NSE expression was scored from 0 to 4, reflecting the percentage of NSE-positive cells.ResultsIn terms of histology as per the World Health Organization criteria (P=0.340), there were no differences between the NSE overexpression (NSE-OE) and NSE underexpression (NSE-UE) groups. The NSE-OE group showed a significantly lower rate of advanced GC (P<0.010), lymph node metastasis (P=0.010), advanced stage group (P<0.010), cancer-related death (P<0.010), and cancer recurrence (P<0.010). Additionally, a Kaplan-Meier survival analysis revealed that the NSE-OE group had longer cumulative survival times than the NSE-UE group (log-rank test, P<0.010). However, there were no significant differences in the serum levels of NSE expression in patients with GC and healthy volunteers (P=0.280).ConclusionsPatients with NSE overexpressing GC tissues showed better prognostic results, implying that NSE could be a candidate biomarker of GC.

Peroxiredoxin IV (PRDX4) is a multifunctional protein that is involved in cell protection against oxidative injury, regulation of cell proliferation, modulation of intracellular signaling, and the pathogenesis of tumors. We previously conducted a proteomic analysis to investigate tumor-specific protein expression in gastric cancer. The aim of the present study was to investigate whether PRDX4 could be a marker of poor prognosis in patients with gastric cancer. Immunohistochemistry was used to validate PRDX4 as a prognostic marker for gastric cancer. Short hairpin RNA (shRNA)-mediated knockdown of PRDX4 expression in AGS cells and MKN28 cells was used for functional studies, and PRDX4 overexpression in PRDX4-depleted cells was used for knock-in studies. Based on immunohistochemistry data, TNM stage and PRDX4 were independent prognostic factors in the Cox proportional hazard model (P<0.05). In the survival analysis, the PRDX4-overexpressing group demonstrated significantly worse survival than the PRDX4-underexpression group (P<0.01). In vitro, knockdown of PRDX4 expression by shRNA caused a significant decrease in cancer invasion. Conversely, overexpression of PRDX4 in PRDX4-depleted cancer cells promoted migration and invasion. By measuring the expression of EMT-related genes, we found that E-cadherin was increased in shPRDX4 cells compared with control shMKN28 cells, and snail and slug were decreased in shPRDX4-1 cells compared with sh-control cells. Furthermore, the expression levels of these genes could be recovered in rescue experiments. In conclusion, the results of the present study suggested that PRDX4 is a marker of poor prognosis in gastric cancer and that PRDX4 is associated with cancer cell migration and invasion via EMT.