A gene expression in study human gastric adenocarcinoma using a cDNA microarray.

Background/aims: cDNA microarray provides a powerful alternative with an unprecedented view scope in monitoring gene expression levels and leads to discoveries of regulatory pathways involved in complicated biological processes. Our aim was to explore the different gene expression patterns in early and advanced gastric cancer.

Methods: By using a cDNA microarray representing 4,608 cDNA clusters, we studied the expression profiling in 10 paired gastric adenocarcinoma samples and the adjacent noncancerous gastric tissues. The alterations in gene expression levels were confirmed by Northern blot and reverse-transcription (RT) PCR.

Results: Genes that were differently expressed in cancer and noncancerous tissues were identified. Forty-four and 92 (26 and 43 of them were known, respectively) genes or cDNA were up- and down-regulated, respectively, in more than 80% of gastric adenocarcinoma samples. The semi-quantitative RT-PCR results were consistent with the microarray findings. To distinguish between early and advanced gastric cancers, we used a supervised learning classification approach. When we used 16 and 20 genes as predictors, the prediction was all yielded statistically significant. Moreover, when we used 9 genes, we could predict with the highest accuracy.

Conclusions: These results may provide not only a new molecular basis for understanding biological properties of gastric adenocarcinoma, but also useful resources for future development of therapeutic targets and diagnostic markers for gastric adenocarcinoma.