Background: Gastric cancer is one of the most frequently diagnosed malignancies in the world. The gene expression profile and molecular grouping of gastric cancer has been a challenging task due to its inherent complexity and variation among individuals.
Aims: To determine the molecular mechanism associated with gastric carcinogenesis.
Methods: We analyzed the gene expression profiles of 20 cancerous tissues and their tumor-adjacent tissue from patients with gastric cancer by using a 14 K cDNA microarray. The differentially expressed genes and their products were verified by semiquantitative reverse transcription PCR (RT-PCR), western blotting and immunohistochemistry of gastric cancer and normal tissue samples.
Results: A total of 69 genes were found to be differentially regulated in the cancerous tissue. Among them, genes such as CDH17, ETV4, S100A6, S100A11, Ephb4, and KLK10 were confirmed by RT-PCR to be up-regulated, while genes such as NK4 and PPP2R1B were down-regulated. Western blotting and immunohistochemistry indicated that Ephb4 was over-expressed and localized to the cytoplasm of gastric cancer cells. Moreover, Ephb4 protein was observed as being significantly related to tumor size and pN category (p = 0.001 and 0.007, respectively).
Conclusions: These newly identified genes might provide a valuable resource for understanding the molecular mechanism associated with the carcinogenesis of gastric cancer and for finding potential diagnostic markers of gastric cancer.