Elevated expression of caveolin-1 in adenocarcinoma of the colon

Caveolins 1, 2, and 3 are the principal proteins of caveolae, the vesicular invaginations of the plasma membrane. several reports have suggested that caveolin-1 may have a role in cellular transformation and tumorigenesis. We studied the expression of caveolin-1 and caveolin-2 in normal epithelium, adenoma, and adenocarcinoma of the colon and their possible role in tumorig enesis. Formalin-fixed, paraffin-embedded sections of 41 cases of adenocarc inoma and 13 cases of adenoma of the colon were stained immunohistochemical ly with anti-caveolin-1 and anti-caveolin-2 antibodies. The expression of c aveolin-1 was elevated in the overwhelming majority of the adenocarcinomas, while most normal colonic epithelium and adenomas showed little or no stai ning. There was significant statistical correlation of the expression of ca veolin-1 with adenocarcinoma but not with tumor stage. Expression of caveol in-2 was undetectable in all of the normal colonic glands, adenomas, and ca rcinomas. We discuss the possible clinical implications of our findings wit hin the context of caveolins and signal transduction.