대한대장항문학회

Purpose : Nitric oxide (NO), the production of which is dependent on Nitric oxide<br>synthase (NOS), has been shown to contribute to pathogeneses in various diseases.<br>Recent investigations of NOS expression in tumor tissues indicate that NO may mediate<br>one or more roles during the growth of human cancers. The aim of this study was to<br>determine whether iNOS is expressed in human colon carcinoma cell lines and to<br>determine the types of NOS isozymes in colon carcinoma cell lines with high and low<br>metastatic potentials. Methods : We measured the expressions of iNOS and eNOS and<br>the formation of nitrotyrosine which indicates peroxinitrate production in highly<br>metastatic colon cancer cell (KM1214) and lowly metastatic colon cancer cell (KM12C)<br>by Western blots. Results : The iNOS were detected in both KM1214 and KM12C by<br>Western blot analysis. The expression of iNOS in KM1214 cells was significantly higher<br>than in KM12C cells. The expression of iNOS was increased with lipopolysaccharide<br>(LPS) in colon cancer cells but the rate of increase was higher in KM1214 cells than in<br>KM12C cells. Conclusions : In human colon carcinoma cells, iNOS is expressed in<br>cancer cells and expression of iNOS is higher in highly metastatic colon cancer cells<br>than in lowly metastatic colon cancer cells and iNOS expression may have some role in<br>colon cancer metastasis.<br>