Identification of Potential Biomarkers for Early and Advanced Gastric Adenocarcinoma Detection

Background/Aiins: This study aimed to under, stand 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.