Genome-wide mRNA profile of human gastric normal and gastric cancer tissues

Gastric cancer is the fourth common cancer and second leading cause of cancer related mortality. The survival probability of gastric cancer patients is often less due to the diagnosis at late stage and also due to the heterogenous nature of tumors. Molecular and transcriptome-wide understanding of the dysregulations in gastric tumors from different populations is highly required to delineate the heterogeneity. To delineate the key oncogenic dysregulations in terms of the transcripts, transcription programs and signaling pathways, we performed genome-wide mRNA profiling of human gastric normal and gastric cancer tissues using Affymetrix Human Transcriptome 2.0 arrays. Gastric cancer and adjacent gatric normal tissues were freshly collected in RNAlater solution and stored at -80°C. Total RNA was isolated from gastric normal and tumor tissues. 50 gastric tumor and 15 adjacent gastric normal tissues, with the RIN value (≥5) were profiled using GeneChip® Human Transcriptome Array 2.0 (HTA-2_0). The differentially expressed genes (DEG's) were analyzed using Transcriptome Analysis Console V4.0. Gene-set enrichment analysis and Gene Ontology analysis of DEG's were used to identify the enrichment of biological pathways and processes involved in gastric carcinogenesis.