Adrenomedullin (ADM), initially identified in human
pheochromocytoma, participates in a wide range of physiological and
pathological processes, including vasorelaxation, angiogenesis and apoptosis. Recent studies have reported that ADM protected
tumor cells against apoptotic cell death via the upregulation of Bcl-2 or the activation of the
phosphatidylinositol 3-kinase/Akt pathway. Several studies have also provided evidence that ADM is involved in
tumor initiation and progression. However, this has not been shown in gastrointestinal
tumors. To investigate the role of ADM in gastrointestinal
tumor progression, we determined the expression levels of ADM in 72 cases of
stomach cancer and 84 cases of
colon cancer and determined whether there was an association between the ADM expression levels and pathological parameters or clinical survival rates. We found that the expression levels of ADM were significantly higher in
colon cancers than in matching normal mucosal tissues. In addition, the expression levels of ADM in
colon cancers were correlated with
cancer stage and clinical survival rate. However, we did not find any significant correlations between ADM expression levels and clinical or pathological parameters in
stomach cancers. Taken together, our data strongly suggest that ADM is involved in the progression of
colon cancer.