Sialosyl-Tn Antigen: Its Distribution in Normal Human Tissues and Expression in Adenocarcinomas

Abstract

In normal adult human tissues, sialosyl-Tn antigen, detected by monoclonal antibody TKH2, was uniformly found in the bronchus, uterus, salivary gland, palatine tonsil, testis, stomach, duodenum, and capillary endothelium of several organs. It was also sporadically found in the small intestine, appendix, colorectum, gallbladder, urinary bladder, skin, and esophagus. The antigen was absent in the other organs. Even in the organs showing positive findings, the antigen was observed only in the limited areas. In contrast, sialosyl-Tn antigen was expressed in a large number of adenocarcinomas in many kinds of organs. It was expressed in more than one half the adenocarcinomas of the pancreas, ovary, uterus, stomach, colorectum, and gallbladder, but not in hepatocellular carcinomas, renal cell carcinomas, and papillary carcinomas of the thyroid gland. Sialosyl-Tn antigen expression also was observed in intestinal metaplasia of the stomach and in transitional mucosa adjacent to the colorectal carcinoma, which are considered to be cancer-related lesions. These results indicate that sialosyl-Tn antigen is a useful tumor marker, especially in adenocarcinomas of the mucin-producing organs, and suggest that the regulation of sialosyl-Tn antigen synthesis in adenocarcinomas is different from that in normal tissues.

RNAi-mediated gene silencing of ST6GalNAc I suppresses the metastatic potential in gastric cancer cells

“…The sialyl-Tn antigen (Neu5Aca2-6Gal-NAca1-O-Ser/Thr), also known as STn and CD175s, is a simple mucin-type carbohydrate antigen. STn is rarely expressed in normal tissue but is aberrantly expressed in a variety of carcinomas, including gastric [9][10][11], colorectal [12], ovarian [13], breast [14,15], and pancreatic [16] carcinomas, in which it is highly correlated with cancer invasion and metastasis [17][18][19].…”

CDX2 homeoprotein is involved in the regulation of ST6GalNAc-I gene in intestinal metaplasia

“…The biosynthesis of STn has been mostly attributed to ST6GalNAc-I activity, both in vitro and in vivo. [1][2][3][4] It is rarely observed in normal tissues but frequently accompanies cancer progression, being one of the most common features of premalignant lesions of the gastrointestinal tract, namely intestinal metaplasia (IM), 5,6 and of carcinomas, namely gastric carcinomas. [5][6][7] However, to date, little is known about ST6GalNAc-I regulation that might explain aberrant expression of STn in preneoplastic and cancer.…”

“…15 Both in the intestine and in IM foci in the stomach, CDX2 is coexpressed with MUC2, 12 ST6GalNAc-I 4 and STn. 5,6 Besides MUC2, CDX2 controls the expression of multiple other intestinal proteins, such as LI-cadherin (LI-cad), 16 sucrase-isomaltase (SI) 17 and CDX2 itself. 18 A chromatin immunoprecipitation (ChIP)-seq analysis performed in the human intestinal cell line Caco-2 has further revealed direct binding of CDX2 to novel target genes and binding sites, namely to a 3′-end enhancer element of the HNF4α gene.…”

Immunohistochemical detection of sialosyl‐Tn antigen in carcinoma of the prostate

“…tissues, STn is found in the limited area of the bronchus, uterus, salivary gland, palatine tonsil, testis, stomach, duodenum, and capillary endothelium of several organs. The glandular epithelium of the normal prostate is References completely negative [9], whereas STn is expressed in…”

“…The specimens were the presence of STn in human gastrointestinal [5], pancreatic [6], ovarian [7] and endometrial [8] carciobtained from Tru-cut needle biopsies or transurethral resection. None of the patients with prostatic carcinoma noma cells, whereas its expression in normal or hyperplastic tissues is highly restricted [9]. STn expression has had received previous endocrine treatment.…”