ABSTRACT
<p><b>OBJECTIVE</b>To screen genes related to peritoneal metastasis of colorectal cancer.</p><p><b>METHODS</b>Specimens of primary cancer and normal mucosa tissues were collected from 3 patients with peritoneal metastasis of colorectal cancer. The total RNA were extracted and inversely transcribed into cDNA to synthesize aRNA using in vitro RNA synthesis. The synthesized aRNA, after labeling with Cy3, were hybridized with the whole human genome oligo microarray. The Empirical Bayes method was used to screen the differentially expressed genes, followed by confirmation of the selected genes by semi-quantitative RT-PCR.</p><p><b>RESULTS</b>With a threshold of P≤0.05, a total of 105 differentially expressed genes were identified in primary cancer lesions, including 42 up-regulated and 63 down-regulated genes. Three of the up-regulated genes (S100P, PRDX1 and SLPI) were selected and confirmed by RT-PCR, which yielded results consistent with those from gene microarray.</p><p><b>CONCLUSION</b>Gene microarray technique can provide valuable clues for locating the tumor markers of peritoneal metastasis in colorectal cancer patients.</p>