[The expression of Tn and S-Tn antigens in cancer and pre-malignant lesion of colorectal tissues by enzyme immunohistochemical method].

Expression of Tn and S-Tn antigens was examined by enzyme immunohistochemical SABC method in cancer, adenoma, hyperplastic polyps, normal adult and fetal colorectal tissues. Both antigens were proved to be oncofetal colorectal cancer-associated. S-Tn was considered to be the better marker, which give no expression in normal adult colorectal tissues, but does express in 81.3% of the cancer tissues, as well as in adenoma. S-Tn increased parallelly with the development of malignant potential changes, such as increasing of size, degree of dysplasia, and increase of villous histological patterns. Experimental data also demonstrated that in colonic cancer cells, a special sialic acid transferase, which is not existent in normal adult colon epithelium, partly changes Tn antigen to S-Tn; thus, T, Tn, and S-Tn antigens are possible to be coexistent in colorectal carcinoma.