Expression of H type 1 antigen of ABO histo-blood group in normal colon and aberrant expressions of H type 2 and H type 3/4 antigens in colon cancer.

We have immunohistochemically examined the distribution of the H antigens of type 1, type 2 and type 3/4 chains of the ABO(H) histo-blood group system in human normal colon and in colon cancer using three monoclonal antibodies specific for each of the H type 1/2, H type 2, and the H type 3/4 chain. We unexpectedly found that mucosa of the normal colon from secretors but not that from nonsecretors expressed only H type 1 and did not express H type 2 or H type 3/4. The H type 1 was expressed in goblet cells. Positive goblet cells expressing H type 1 were decreased in number progressively from the proximal colon to the rectum. In tumors, 4 (57%) of 7 cancer tissues of the proximal colon from secretors expressed no H type 1, whereas all 8 cancer tissues of the distal colon from secretors expressed H type 1. The aberrant expressions of H type 2 and H type 3/4 (47 and 67%, respectively) were found in cancer tissues from both the proximal and the distal colon. Tumors from nonsecretors did not express any H antigens. Our results suggested that the expression of H type 1 in the normal colon and the aberrant expressions of H type 2 and H type 3/4 in colon cancer tissues were regulated by FUT2-encoded Se type α(1,2)fucosyltransferase. However, UEA-I-positive substance(s) rather than H type 2 were uniquely expressed throughout the normal colon and in colon cancers from both secretors and nonsecretors.