Background/aims: This study aimed to understand gradual biological variations during gastric tumorigenesis, and to identify the candidate genes that are involved in tumor progression and metastasis.
Methodology: cDNA microarray data were obtained from 10 pair of cancerous and normal adjacent tissue from gastric adenocarcinoma patients. The samples were divided in primary and advanced gastric adenocarcinoma with lymph node metastasis. Validation of the microarray data was accomplished by quantitative RT-PCR on additional 41 samples. The significantly modified genes were grouped in clusters according to their functional annotation, and comparison was done regarding molecular mechanisms involved tumor progression.
Results: A total of 136 genes were up-regulated and 96 genes were down-regulated by at least fourfold in tumor tissue. The analysis of gene clusters revealed a complex remodelling of normal gastric epithelium morphology and function associated with the tumorigenesis and metastasis. A large number of proteases are being overexpressed, together with keratins, genes associated with morphogenesis and anti-apoptosis. Between the most significant down-regulated genes, there were genes involved in gastric motility and synthesis and genes related to metabolic and pro-apoptotic processes. We also report, the identification of seven genes, significant up-regulated, that seem to be associated with tumor progression: KRT17, COL10A2, KIAA1199, SPP1, IL11, S100A2, and MMP3.
Conclusions: Our cDNA microarray study identified several genes that appeared to meet the criteria of a good biomarker, and may therefore be especially useful for the development of diagnostic tools, for the early detection, or for the prediction of tumor progression.