Expression of LeYand Extended LeYBlood Group-related Antigens in Human Malignant , Premalignant , and Nonmalignant Colonie Tissues 1

The LeY determinant, a difucosylated type 2 blood group-related antigen, is a positional isomer of the Leb blood group antigen and a fucosylated derivative of the Lex antigen. The Le" antigen behaves like an oncodevelopmental tumor-associated antigen in human colon cancer, and extended polyfucosyl Lex antigens are more specific for colon cancer tissues than are simple, monofucosyl Le" antigens. The present investi gation compared the expression of simple and extended Le* antigens in a variety of malignant and nonmalignant human colonie tissues to gain insight into the normal distribution and cancer-associated expression of these antigens. Monoclonal antibody \I! -(>. which recognizes the LeY epitope irrespective of its carrier carbohydrate chain, stained the majority of specimens regardless of malignant potential or location within the colon. In contrast, CC-1 and CC-2 monoclonal antibodies, which recognize extended LeY structures, and M I-I. which is specific to trifucosyl Lev, preferentially stained malignant colonie tissues and rarely stained normal colonie mucosae. Mucosa immediately adjacent to cancer usually stained with AU-i. but not with KH-1, CC-1, or CC-2. Extended or trifucosyl Lev antigen expression was limited exclusively to premalignant (adenomatous) polyps and was invariably absent from nonpremalignant (hyperplastic) polyps. Moreover, among adenomatous polyps, extended Lev antigen expression tended to correlate with three parameters of malignant potential: larger polyp size; Â» Â¡linns histology, and severe dysplasia. A116 failed to distinguish between hyperplastic and adenomatous polyps. In second-trimester fetal colonie mucosa, A11-6bound to both proximal and distal segments whereas KH-1, CC-1, and CC-2 bound only to proximal segments. We conclude that in human colon, the Lev hapten is an oncodevelopmental cancer-associated antigen and extended LeYantigens are highly specific markers for malignancy and premalignancy. INTRODUCTION With the advent of hybridoma technology, numerous Mabs4 have been prepared which recognize cancer-associated antigens. Among the Mabs that hold promise for the detection of gas trointestinal malignancies, many have been demonstrated to recognize carbohydrate structures related to blood group anti gens. Some of these cancer-associated antigens include the A, B, and H blood group substances (1, 2), Le" and Leb (2-5), sialylated Le" (6), Lex (7), sialylated Lex (8, 9), I(Ma) (5), and T-antigen(lO). Received 3/4/86; revised 7/22/86; accepted 7/25/86. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. 1Supported by the Veterans Administration Medical Research Service (Y. S. K., M. Y., S. H. I., Q. S.); VA Medical Investigator Award (Y. S. K.); VA Associate Investigator Award (S. H. I.); and Grant CP15738 from the Division of Cancer Cause and Prevention, National Cancer Institute, NIH (B. F. T.). The work participated in by T. K. and S. H. (preparation of KH-1 antibody) has been supported by a grant from the Otsuka Research Foundation. The preparation of AH6 antibody was supported by NIH grant GM 23100 (S. H.). 2 Medical Investigator of the Veterans Administration. To whom requests for reprints should be addressed, at G. I. Research Lab (151M2), VA Medical Center, 4150 Clement St, San Francisco, CA 94121. 3Present address: Japan Immunoresearch Laboratories, Takasaki-shi, Gumma-ken, Japan. 4 The abbreviations used are: Mab, monoclonal antibody: GlcNAc: yV-acetylglucosamine; HP, hyperplastic polyps; AP, adenomatous polyps; TM, transitional The LeY antigen [Y hapten] is a difucosylated tetrasaccharide [Fucal-Â»2GaI/31->4(Fucal-Â»3)GlcNAc] found on type 2 blood group oligosaccharides of glycolipids (11-16) and glycoproteins (14, 17). This antigen is a positional isomer of the Leb blood group antigen and a fucosylated derivative of the Lex hapten (see Table 1). Studies have identified the Lev antigen in various human tissues including ovarian cyst fluid (17), adult intestine (11), fetal intestine (12), erythrocytes (13), granulocytes, gastric mucosa, gastric secretions (14), urine from a lactating mother (15), and recently a colon cancer liver metastasis (16). By immunization of mice with cell lines derived from human gastric cancer (16), lung cancer (18), and ovarian teratocarcinoma (19) and with membranes from a human colonie adenoma (14), several Mabs have been raised which recognize the Lev determinant (Table 1). Immunohistochemical observations suggest that the LeYhap ten behaves as an oncodevelopmental cancer-associated antigen in the human colon (24), although other normal gastrointestinal and extraintestinal tissues also express this antigen (25-27). These immunohistochemical observations were performed us ing Mabs that recognize the LeYepitope regardless of the length of its carrier oligosaccharide side chain (so-called "simple" LeY determinant). Recently, however, LeY determinants present on extended oligosaccharide side chains have been isolated from metastatic colon cancer cells (Table 1), and Mabs have been developed which preferentially recognize these elongated epitopes. Two Mabs, CC-1 and CC-2, prepared by immunizing mice with the human colon cancer cell line HT-295 react preferentially with extended LeY epitopes, and Mab KH-1, raised against purified trifucosyl nonaosylceramide LeY, has a specific affinity for an extended Y determinant with internal fucosylation (trifucosyl LeY) (20). To date no information is available concerning the histological distribution of the LeY antigens defined by antibodies that can discriminate between extended LeYor internally fucosylated Lev and simple (or short chain) Lev. Because an earlier immu nohistochemical study demonstrated that in human colon can cer tissues extended Lex antigens demonstrated greater tissue specificity than short chain (simple) Lex antigens (28), we decided to compare the expression of simple Lev and extended LeY (with and without internal fucosylation) in various malig nant, premalignant, and nonmalignant colonie tissues. MATERIALS AND METHODS Tissues. Unless stated otherwise, "proximal" colon refers to cecum, ascending colon, and transverse colon, and "distal" colon refers to descending colon, sigmoid colon, and rectum. Fetal colonie tissue was obtained from 13 second-trimester abortuses as approved by the Human Experimentation Committee of the University of California, San Fran5Q. Sun, B. Siddiqui, E. Nudelman, S. Hakomori, J. J. L. Ho, and Y. S. Kim. Murine monoclonal antibodies to a human colonie cancer-associated glycolipid, submitted for publication.