The endothelin axis in the metastatic process of colon carcinoma.

BACKGROUND The endothelin axis has recently emerged as an important factor in tumour metastasis. The aim of this study was to investigate the endothelin axis and its downstream pathways related to metastasis in colon carcinoma. MATERIALS AND METHODS mRNA expression of 36 genes associated with the endothelin axis in 18 non-metastatic and 20 metastatic colon carcinomas with individual-matched normal mucosa were evaluated using real-time reverse transcription polymerase chain reaction. RESULTS Seventeen out of 36 genes, including endothelin A receptor, were significantly overexpressed in the tumour tissue compared to the individual-matched normal mucosa. Seven out of 36 genes, including endothelin B receptor, were significantly down-regulated in tumour tissue. Phosphatase and tensin homolog (PTEN) was significantly down-regulated in the metastatic patients compared to the non-metastatic patients. CONCLUSION This study indicated that central genes in the endothelin axis are overexpressed when colon tissue becomes malignant. Down-regulation of PTEN may promote a progressive phenotype of colon carcinomas.