Abstract:
Present study aimed to investigate biomarkers for early diagnosis and prognosis of gastric cancer. For this purpose, ten of the most recent gene expression profiles were chosen (GSE54129, GSE79973, GSE161533, GSE103236, GSE33651, GSE19826, GSE118916, GSE112369, GSE13911 and GSE81948) and analyzed to identify common differentially expressed genes (DEGs). Microarray based datasets were arranged in subsets of different datasets combinations (i.e., 5, 4, 3). All subsets were subjected to extensive in silico analysis. One of the five-five datasets combination scheme (GSE161533, GSE54129, GSE33651, GSE19826, and GSE79973) shared one DEG, i.e., ESSRG. Two four-four dataset combination schemes shared one DEG, respectively, i.e., ESSRG and RAB31. Among three-three datasets schemes, first datasets combination scheme (GSE13911, GSE581948, GSE79973) had eighteen shared DEGs (CWH43, ATP4B, ATP4A, TRIM50, ESRRG, KCNJ16, CCKBR, GHRL, ADH7, AQP4, LINC00982, COL6A3, COL12A1, FGD4, DGKD, SPARC, CKMT2, KCNJ15), second datasets combination scheme (GSE19826, GSE79973, GSE103236) had eight shared DEGs (ESRRG, CCKBR, CKMT2, APOBEC2, THY1, BGN, TIMP1, SPARC), third datasets combination (GSE19826, GSE13911, GSE103236) had five shared DEGs (ESRRG, CCKBR, CKMT2, ATP11A, SPARC), and fourth datasets combination (GSE19826, GSE79973, GSE118916) had three shared DEGs (ESRRG, TMEM161B, ADH7). Among all these DEGs, five genes including ATP4B, ATP4A, CCKBR, KCNJ15, and KCNJ16 were identified as the part of gastric acid secretion, and collecting duct acid secretion pathways. Further expression validation of these five genes using three additional datasets (GSE31811, GSE26899, and GSE26272) confirmed their significant up-regulation in gastric cancer samples relative to normal controls. Finally, through survival analysis, we noted that higher expressions of these 5 DEGs were also associated with poor survival durations of the gastric patients. In conclusion, this study revealed a panel of 5 genes, which might be used for diagnostic purpose in gastric cancer patients.