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S H Itzkowitz

Publications and source records attributed to S H Itzkowitz.

At least 55 records · Page 3Linked to original sources
PubMed1989

Expression of Tn, sialosyl-Tn, and T antigens in human colon cancer.

Mucin glycoproteins are major secretory products of the colon and contain O-linked oligosaccharides synthesized on a polypeptide backbone. The initial step in the synthesis of O-linked oligosaccharides is the addition of N-acetylgalactosamine to serine or threonine residues forming the Tn antigen. This substance can then receive additional carbohydrate residues such as sialic acid to form sialosyl-Tn antigen, or galactose to form T antigen. In the colon, the T antigen is an oncodevelopmental cancer-associated antigen but little is known about Tn and sialosyl-Tn expression. The present comparative immunohistochemical study was performed to analyze the expression of these antigens in fetal, normal adult, and malignant colorectal tissues with an aim toward elucidating whether Tn and sialosyl-Tn are also oncodevelopmental colon cancer-associated antigens and to gain insight into the earliest steps of mucin glycosylation in colonocytes. We used three reagents to detect Tn antigen (two monoclonal antibodies ETn1.01 and CU-1, and one lectin Vicia villosa), two reagents to detect sialosyl-Tn (monoclonal antibodies TKH2 and B72.3) and one to detect T antigen (monoclonal antibody AH9-16). Except for occasional reactivity with VVA and CU-1, cells of normal colonic mucosa did not express Tn, sialosyl-Tn, or T antigens. However, in the transitional mucosa immediately adjacent to cancer, all three antigens were expressed (ranging from 35 to 67% of cases depending upon the reagent). In colon cancers, the percentage of cases expressing each antigen were as follows: Tn 72-81%, sialosyl-Tn 93-96%, and T 71%. Unlike T antigen, which was preferentially expressed by moderately well- and well-differentiated adenocarcinomas, both Tn and sialosyl-Tn antigens were expressed by most histological subsets of colon cancers, including poorly differentiated adenocarcinomas and mucinous (colloid and signet ring cell type) carcinomas. The majority of cancers expressed both Tn and sialosyl-Tn, usually in association with T antigen. Only one cancer lacked all three antigens. Fetal colonic mucosal cells expressed all three antigens, particularly in goblet cell mucin. These results indicate that like T antigen, Tn and sialosyl-Tn are oncodevelopmental cancer-associated antigens in the colon. Moreover, Tn and sialosyl-Tn antigens appear to be useful markers of poorly differentiated adenocarcinomas and mucinous carcinomas: two histological subsets that often fail to express other cancer-associated antigens and that are often associated with a poor clinical outcome.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibodies, Monoclonal↗
PubMed1989

Cell lineage markers in premalignant and malignant colonic mucosa.

Normal colonic epithelial cells consist of several cell types or lineages that are thought to arise from a common stem cell precursor. Neoplastic transformation may occur at different stages in the differentiation of a colonic stem cell to produce tumors that may retain characteristic cell lineage phenotypes. In this study, immunohistochemical techniques were used to identify cell lineage-related markers in fetal, normal, hyperplastic, adenomatous, and cancerous colonic tissue. These markers consisted of secretory component (columnar cells), a purified mucin antigen (mucous or goblet cells), chromogranin A (enteroendocrine cells), lysozyme (Paneth cells), and carcinoembryonic antigen (panepithelial cell marker). Colonic neoplasms, like normal mucosa, predominantly expressed the markers of columnar and goblet cell lineages. Chromogranin A was expressed in a small population of cells in most normal and fetal colonic crypts. Chromogranin A reactive cells were found in 55% of hyperplastic polyps, 31% of adenomatous polyps, and 33% of carcinomas. Lysozyme reactivity was rare in fetal, normal, and hyperplastic specimens, but was present in 86% of adenomas and 40% of carcinomas. Of 42 primary carcinomas, 9% were "pluripotent" and expressed markers of all four cell lineages. In addition to columnar and goblet cell markers, 7% expressed both enteroendocrine and Paneth cell markers, 17% expressed enteroendocrine cell markers, and 24% expressed Paneth cell markers. Two cases (5%) lacked expression of any of the cell lineage markers. The remainder expressed only columnar and goblet cell markers. The markers used in this study appear to identify the major cell lineages of fetal and normal colonic epithelium and can be used to delineate the altered cell lineage phenotypes in premalignant and malignant colonic mucosa.

Biomarkers, Tumor↗
PubMed1989

The expression of colorectal carcinoma-associated antigens in the normal colonic mucosa. An immunohistochemical analysis of regional distribution.

Immunohistologic studies were performed to evaluate the expression and regional distribution of 20 colorectal carcinoma-associated antigens in the colonic mucosa of 12 normal adults. A distinct regional variation was seen in the expression of blood group A, B, Lewis(b), and extended Lewis(y) antigens, which were expressed predominantly in the right colon, whereas Lewis(a), Lewis(y), and H-type 2 were prevalent throughout. Lewis(x) and X-like antigens were only occasionally expressed. Two antibodies against sialylated Lewis(a) showed different staining patterns, with CA19.9 positive in only two biopsies and CO29.11 intensely positive in most. Two of the three antibodies detecting carcinoembryonic antigen epitopes (3d6 and COL-4) stained many biopsies, whereas COL-12 was rarely detected. No regional gradient was found in the expression of the other antigens studied (B72.3, ME491; GA73.3, ND1, and ND4). This mapping data will provide an important baseline for future studies of epitope distribution in the colon in premalignant and neoplastic conditions.

ABO Blood-Group System↗
PubMed1988

Immunohistochemical comparison of Lea, monosialosyl Lea (CA 19-9), and disialosyl Lea antigens in human colorectal and pancreatic tissues.

The CA 19-9 antigen is a monosialosyl Lea blood group antigen which has been shown to be a useful tumor-associated antigen for the diagnosis of gastrointestinal cancers. Recently, a sialylated derivative of this antigen, disialosyl Lea, was isolated from a colon cancer liver metastasis and a monoclonal antibody (FH7) recognizing this novel determinant was developed. The present study simultaneously compared the expression of Lea, monosialosyl Lea, and disialosyl Lea antigens in a variety of nonmalignant, premalignant, and malignant tissues of the colorectum and pancreas with an aim toward elucidating whether disialosyl Lea is expressed as a tumor-associated antigen. In normal colonic mucosa, disialosyl Lea expression closely resembled Lea expression in overall frequency, segmental distribution, and cellular localization whereas monosialosyl Lea (CA 19-9) was essentially absent. Along the crypt axis, Lea was more often expressed in goblet cells of the upper crypt whereas disialosyl Lea was found in goblet cells along the entire crypt. Fetal colonic mucosa expressed all three antigens, as did most colorectal cancers regardless of location within the colon or degree of differentiation. The majority of hyperplastic polyps and practically all adenomatous polyps also expressed these three antigens, and in adenomas, antigen expression was independent of polyp size, villous morphology, or degree of dysplasia. In the normal pancreas, the three antigens were expressed on ductal, ductular and centroacinar cells of all specimens. The majority of pancreatic cancers expressed all three antigens. Thus, in the normal colon, the absence of monosialosyl Lea (CA 19-9) in the presence of disialosyl Lea suggests that an alpha 2,6 sialyltransferase is active, which results in the masking of CA 19-9 antigen expression. These results further support the concept that specific sialyltransferases play a role in regulating the expression of tumor-associated antigens.

Antibodies, Monoclonal↗
PubMed1988

Lex and Ley antigen expression in human pancreatic cancer.

Carbohydrate antigens are useful markers for the serological detection of pancreatic cancer. However, data concerning the expression of structurally well-defined carbohydrate antigens in normal and malignant pancreatic tissue is quite limited. The Lex and Leg antigens are closely related carbohydrate antigens synthesized on type 2 blood group oligosaccharide side chains of glycolipids and glycoproteins. Monoclonal antibodies anti-SSEA-1 and AH6 recognize "simple" Lex and Ley epitopes, respectively, regardless of the length of the carrier carbohydrate. Other monoclonal antibodies recognize Lex (FH4), sialyl Lex (FH6, IB9) or Ley (KH1, CC-1, CC-2) carried only by elongated type 2 side chains with or without internal alpha 1,3 fucosyl substitution. The present comparative immunohistochemical study used tissues of normal pancreas, chronic pancreatitis, and pancreatic cancer to determine the normal expression of Lex and Ley antigens in the pancreas and to elucidate any cancer-associated alterations. Lex-related antigens were not expressed in normal pancreas, expressed in only 10-20% of chronic pancreatitis tissues, but expressed in 50-70% of pancreatic cancer tissues. The frequency of Lex-related antigen expression in pancreatic cancer tissues was lowest in poorly differentiated cancers. Within a given specimen, at least three or all four of the Lex recognizing monoclonal antibodies were simultaneously expressed. Unlike Lex antigens, Ley-related antigens were expressed in 32-77% of specimens of normal pancreas, with similar frequencies in specimens of chronic pancreatitis and pancreatic cancer. In normal pancreas, simple Ley was expressed by both ductal and acinar cells, but extended Ley antigens were expressed only by acinar cells. In pancreatic cancer, extended Ley antigen expression was found in less than 10% of poorly differentiated tumors. Coexpression among the Ley-related antigens was less common than with the Lex-related antigens. Also in cancer specimens, simple Lex and simple Lex antigens were often concordantly expressed, whereas extended Lex and extended Ley antigen expression was often discordant. Hyperplastic ducts and ductules associated with pancreatic cancer expressed Lex-related antigens more frequently than morphologically similar lesions associated with chronic pancreatitis. These results demonstrate that Lex-related antigens are cancer-associated determinants in the human pancreas. The discrepant expression between Lex and Ley antigens in these tissues implies altered regulation of fucosyltransferase activity associated with the malignant state.

Antibodies, Monoclonal↗
PubMed1988

A comparison of three immunoperoxidase techniques for antigen detection in colorectal carcinoma tissues.

We compared the streptavidin-peroxidase conjugate (SP) method of immunoperoxidase histochemistry to the unlabeled antibody (PAP) and avidin-biotin-peroxidase complex (ABC) techniques in human colorectal carcinoma tissues stained with a monoclonal antibody for expression of carcinoembryonic antigen. Compared to the ABC and PAP method, the SP method produced stronger staining intensity and very low background staining. This was true when other antibody isotypes, other antibody species, other organs, and another tumor-associated antigen were used. Moreover, the SP procedure time could be reduced to one third that of the ABC or PAP methods without compromising accuracy, and the SP reagent is stable for several months. The chemical nature of the streptavidin molecule accounts, in large part, for the advantages of the SP method.

Avidin↗
PubMed1988

Carbohydrate antigen expression in the adenoma-carcinoma sequence.

Several alterations in carbohydrate antigen expression can occur in colon cancers. Modified structures such as extended LeX and LeY antigens could serve as cancer-associated antigens in the human colon, although none is specific only for colon cancer. Since LeX and LeY antigens are present in fetal tissues, but not in adult normal tissues, these antigens appear to be oncodevelopmental in nature. The expression in colon cancers of extended LeX and LeY antigens with internal fucosylation or terminal sialylation is considered rather cancer-specific since normal colonic mucosa does not express these antigens. Furthermore, these molecules may also be "markers" for premalignancy, since adenomatous polyps, but not hyperplastic polyps are capable of exhibiting these changes and antigenic expression often correlates with malignant potential in adenomatous polyps. The precise biochemical and molecular mechanisms for these alterations in LeX and LeY expression and their biological significance are not well understood at the present time. However, it is likely that the regulation of the glycosyltransferase enzymes responsible for the processes of polylactosamine elongation, fucosylation, and sialylation may be aberrant. Obviously further studies are needed to elucidate these mechanisms. However, it appears that the monoclonal antibodies directed against extended LeX and LeY antigens are a useful adjunct in the diagnosis of colonic neoplasia, and may also be helpful in elucidating the molecular and biochemical mechanisms involved in the adenoma-carcinoma sequence.

Adenoma↗
PubMed1987

An animal model for colon cancer metastasis: establishment and characterization of murine cell lines with enhanced liver-metastasizing ability.

A detailed understanding of the pathogenesis of colon cancer metastasis has been hindered by the lack of appropriate animal models which accurately reflect events in this complex process. An animal model for colon cancer metastasis is described in which spontaneously metastasizing colonic tumors are formed after injection of murine colon cancer cells into the cecal wall of BALB/c mice. Using this model, tumor cells with different liver-metastasizing potential were selected and shown to possess several properties known to be associated with other metastatic cell lines. The ability of tumor cells to invade a reconstituted basement membrane and to secrete type IV collagenase was directly proportional to their metastatic ability. In addition, liver-metastasizing cells preferentially migrated toward liver extracts in a Boyden chamber assay, as compared to extracts of brain or lung, and adhered rapidly to highly purified hepatic sinusoidal endothelial cells versus hepatic parenchymal cells in vitro. This model may thus be useful for studying many aspects of the pathogenesis of colon cancer metastasis.

Animals↗
PubMed1987

Cancer-associated alterations of blood group antigen expression in the human pancreas.

Certain alterations of blood group substance (BGS) expression have been observed in gastrointestinal cancer tissues. However, in the pancreas little is known about BGS expression by normal or malignant tissue. The present immunohistochemical study analyzed simultaneously the expression of A, B, H, Lewisa (Lea), and Lewisb (Leb) antigens in specimens of normal pancreas, chronic pancreatitis, and pancreatic carcinoma (primary and metastatic). In normal pancreas all five antigens were expressed in ducts, ductules, and acini, but not in islets. Acinar cells expressed A, B, H, and Leb in supranuclear cytoplasm, whereas Lea was found mainly on centroacinar cells. Only BGSs that were appropriate for the host's blood type were expressed, except for one case of Lea deletion. BGS expression by chronic pancreatitis tissue closely resembled that by normal tissue. In primary pancreatic cancer two cancer-associated alterations were noted that were not found in either normal pancreas or chronic pancreatitis. Deletion of an expected A, B, H, or Leb antigen occurred in approximately 25% of cases, particularly in more poorly differentiated cancers. Incompatible expression of an unexpected A or B antigen occurred in 33% of cases, regardless of degree of differentiation. Metastatic pancreatic cancers also exhibited BGS deletion and incompatibility. In both primary and metastatic cancers the incidence of incompatible A or B expression was higher in cancers from the United States than in cancers from Japan, but the incidence of BGS deletion was similar between the two countries. It was concluded that deletion of A, B, H, or Leb antigens and incompatible expression of A or B antigens are cancer-associated events in the pancreas.

ABO Blood-Group System↗
PubMed1987

Expression of LewisX and sialylated LewisX antigens in human colorectal polyps.

The LewisX (LeX) antigen [characterized by trisaccharide Gal beta 1----4 (Fuc alpha 1----3)N-acetylglucosamine] is an oncodevelopmental antigen in the human colon. Monoclonal antibodies (MoAbs), anti-SSEA-1 and AH8-183, which recognize LeX antigen either on short oligosaccharide side chains or as a terminal immunodeterminant on longer carbohydrate side chains of glycoconjugates, bind to most colon cancer tissues but also to some normal colon mucosae. However, the monoclonal antibodies FH1, FH4, FH6, and IB9, which recognize extended difucosylated and trifucosylated LeX structures or their sialylated derivatives, are more cancer-associated because they rarely bind to normal colon mucosa. In the present study, these MoAbs were used to compare the expression of various LeX-related antigens in premalignant (adenomatous) and nonpremalignant (hyperplastic) colorectal polyps. Antigen expression in polyps was also compared to antigen expressions of normal colon mucosa and colon cancer tissues. The four MoAbs recognizing extended LeX antigens bound to adenomatous polyps (APs) significantly more than to hyperplastic polyps (HPs). In contrast, anti-SSEA-1 and AH8-183 recognizing monofucosyl LeX were less able to distinguish between APs and HPs. In APs, staining with the four MoAbs recognizing extended LeX antigens correlated with the premalignant parameters of larger polyp size, more severe dysplasia, and increased villose component. However, staining with AH8-183 correlated only with polyp size, and anti-SSEA-1 correlated only with polyp size and degree of dysplasia. In general, the staining frequency of HPs was similar to that of normal colon mucosa, although FH6, which did not stain any specimens of normal mucosa, stained a few HPs. The staining frequency of APs was less than that of colon cancer tissues, but these differences were generally not statistically significant. In conclusion, extended LeX antigens and their sialylated derivatives are cancer-associated antigens that are expressed preferentially in premalignant colon polyps, that tend to correlate with malignant potential in these polyps, and that may eventually help to define mechanisms involved in the polyp-to-cancer sequence.

Antibodies, Monoclonal↗
PubMed1986

Conditions that mimic inflammatory bowel disease. Diagnostic clues and potential pitfalls.

Many of the features that identify idiopathic inflammatory bowel disease are also found with other colorectal conditions that are often encountered by the primary care physician. Although, initially, symptoms of these disorders may appear to be caused by ulcerative colitis or Crohn's disease, the cause could be bacterial, viral, parasitic, or fungal infection. Ischemic colitis and radiation colitis are other conditions that are similar in presentation to ulcerative colitis. In most cases, the physician should be able to make a differential diagnosis from a thorough history and physical examination, anoscopy or sigmoidoscopy, rectal biopsy, stool examination, and serology. An occasional patient, in whom diagnosis is not made by these methods, may require a barium enema study, colonoscopy, or referral to a gastroenterologist.

Colitis, Ulcerative↗
PubMed1986

Heterogeneous expression of two oncodevelopmental antigens, CEA and SSEA-1, in colorectal cancer.

Colorectal carcinomas are composed of heterogeneous cell subpopulations which may be instrumental in conferring metastatic potential and therapeutic refractoriness to these tumours. To assess cellular heterogeneity, the expression has been examined of two oncodevelopmental antigens, carcinoembryonic antigen (CEA) and stage-specific embryonic antigen 1 (SSEA-1), by double immunofluorescence microscopy on 11 human colorectal carcinomas. Although both antigens were expressed in each tumour, their regional and cellular locations differed considerably. SSEA-1 expression was rarely expressed in poorly differentiated cancers but was enhanced with increasing degrees of differentiation. CEA expression was independent of histological differentiation. SSEA-1 was expressed with similar frequency in cell membranes, cytoplasm, and glandular contents regardless of degree of differentiation. Cytoplasmic staining with CEA however, was limited to more poorly differentiated tumours. In normal mucosa remote from the tumours and transitional mucosa adjacent to them, SSEA-1 stained only a few lower crypts whereas CEA stained a majority of both upper and lower crypts. Although biochemical studies have indicated that the SSEA-1 epitope may reside on CEA molecules, the fact that colon cancer tissues express these two antigens quite heterogeneously suggests differences in antigenic processing which may be dependent upon the degree of cellular differentiation.

Adenocarcinoma↗
PubMed1986

Cancer-associated alterations of blood group antigen expression in human colorectal polyps.

Human colorectal carcinoma tissues may exhibit several patterns of altered blood group substance (BGS) expression: reappearance of A, B, H, or Lewisb antigens in distal colon; deletion of BGS in the proximal colon with or without precursor substance accumulation; and incompatible BGS expression in proximal or distal colon. The present study evaluated these cancer-associated alterations in colorectal polyps with different malignant potential. With respect to ABH antigens, hyperplastic polyps (HPs), considered to have no malignant potential, did not exhibit incompatibility and only a few cases demonstrated BGS reappearance or deletion. Adenomatous polyps (APs) however, frequently reexpressed ABH antigens or expressed incompatible BG-A or B in 27% of polyps; one specimen demonstrated BG-B deletion. Precursor expression was not found in HPs but was frequently observed in APs. Reappearance of ABH in distal polyps was significantly correlated with increasing grade of dysplasia, but was not significantly correlated with polyp size or histological type. With respect to Lewis antigen expression, Lewisb reappearance occurred in almost every distal polyp, and Lewisa-Lewisb coexpression was also quite common. Lea deletion was frequently noted, especially in HP, but the significance of this finding is unclear. This study indicates that several antigenic alterations that occur in colorectal cancer tissues also appear in premalignant polyps, and often in early stages of the neoplastic process. The observation that incompatible expression of BG-A or B occurs only in AP and cancer tissues (as well as mucosa adjacent to cancer) but not in fetal colonic mucosa, adult normal colonic mucosa, or HP, suggests that this may be a cancer-specific phenomenon.

ABO Blood-Group System↗
PubMed1986

Expression of LeY and extended LeY blood group-related antigens in human malignant, premalignant, and nonmalignant colonic tissues.

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 LeX 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 LeX antigens. The present investigation compared the expression of simple and extended LeY antigens in a variety of malignant and nonmalignant human colonic tissues to gain insight into the normal distribution and cancer-associated expression of these antigens. Monoclonal antibody AH-6, 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 KH-1, which is specific to trifucosyl LeY, preferentially stained malignant colonic tissues and rarely stained normal colonic mucosae. Mucosa immediately adjacent to cancer usually stained with AH-6 but not with KH-1, CC-1, or CC-2. Extended or trifucosyl LeY antigen expression was limited exclusively to premalignant (adenomatous) polyps and was invariably absent from nonpremalignant (hyperplastic) polyps. Moreover, among adenomatous polyps, extended LeY antigen expression tended to correlate with three parameters of malignant potential: larger polyp size; villous histology, and severe dysplasia. AH-6 failed to distinguish between hyperplastic and adenomatous polyps. In second-trimester fetal colonic mucosa, AH-6 bound 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 LeY hapten is an oncodevelopmental cancer-associated antigen and extended LeY antigens are highly specific markers for malignancy and premalignancy.

Antibodies, Monoclonal↗
PubMed1986

Lewisx- and sialylated Lewisx-related antigen expression in human malignant and nonmalignant colonic tissues.

Biochemical studies have revealed that some normal cells express the LeX trisaccharide Gal beta 1----4(Fuc alpha 1----3)GlcNAc either on short-chain fucolipids or as a single immunodeterminant on glycolipid oligosaccharide side chains. Cancer cells, including those from colonic adenocarcinomas, express this antigen on longer type 2 blood group side chains as difucosylated or trifucosylated fucolipids. Moreover, sialylated forms of difucosylated LeX also accumulate in colon cancer but not in normal colonic mucosa. In the present study, six monoclonal antibodies which selectively recognize the various LeX-related antigens were used for immunohistochemical examination of these antigens in serial sections of human colonic tissue. All of these antigens were oncodevelopmental in human colon. Monoclonal antibodies anti-SSEA-1 and AH8-183, directed against short-chain, monofucosylated LeX, were unable to discriminate well between normal and malignant colonic tissue. However, the other four antibodies were much better at distinguishing cancer from normal tissue. FH6 was the most specific in that no normal tissues bound this antibody. However, FH6 failed to stain poorly differentiated cancers and some colloid-type carcinomas. FH4, which was also highly specific, stained almost all cancers, regardless of the degree of differentiation. FH4 primarily stained cancer cell cytoplasm, whereas the sialylated antigen defined by FH6 predominantly stained cell membranes. Differences were noted between the expression of LeX-related antigens in autopsied normal mucosa compared to mucosa of benign colonic diseases. Monoclonal antibodies recognizing long-chain polyfucosylated and sialylated LeX-related antigens appear to be useful tools for detection of colon cancer.

Antibodies, Monoclonal↗
PubMed1986

Comparison of T-antigen expression in normal, premalignant, and malignant human colonic tissue using lectin and antibody immunohistochemistry.

The Thomsen-Friedenreich antigen has been implicated as a cancer-associated antigen in some human organs including the colon. Most previous studies of Thomsen-Friedenreich antigen expression in the colon used peanut agglutinin (PNA) to identify the immunodeterminant in tissues. However, evidence from other organs suggests that anti-T antibodies have specificities which differ from those of peanut lectin. To elucidate the nature of the T-immunodeterminant in colonic mucosa, we compared staining by PNA to that of a polyclonal (PAb) and monoclonal (MAb) anti-T antibody. PNA demonstrated the best sensitivity (91%) in cancer tissues but the lowest specificity (68%) in normal mucosa. Staining with MAb was only 76% sensitive but 100% specific. Sensitivity and specificity of PAb were intermediate between PNA and MAb. MAb stained fewer adenomatous polyps than either PNA or PAb, but staining appeared to correlate with premalignant features of the polyps. PNA-binding sites were more prevalent than either PAb or MAb in hyperplastic polyps. Cell cytoplasm was stained by both antibodies more often than by PNA. The majority of fetal colonic specimens stained with all three reagents suggesting that Thomsen-Friedenreich antigen may be an oncodevelopmental antigen in human colon. Differences in staining patterns in some tissues may be due to different antigenic specificities among PNA, PAb, and MAb.

Adenoma↗