The binding of peroxidase-labelled lectins to human breast epithelium. III--Altered fucose-binding patterns of breast carcinomas and their significance

Lectin histochemistry for light and electron microscopy

Glycoconjugates are complex macromolecules present in all tissues throughout the body. Depending on the tissue region, glycoconjugates express different carbohydrate moieties, which can be used to both distinguish cell type and examine changes in cell phenotype.Although the periodic acid-schiff (PAS) method has long been used to study the distribution of glycoconjugates, the usefulness of the technique is severely limited by its lack of specificity. A more specific technique makes use of the affinity that plant-derived lectins have for different carbohydrate moieties in glycoconjugates. Binding of lectins is therefore a particularly useful adjunct to conventional histology when it is important to characterise cell type. These well-characterised binding patterns have proved particularly valuable in helping us understand the pathogenesis of kidney disease, changes in cell surface carbohydrates on normal and neoplastic cells in tumours, and blood group biology.When labeled with a reporter molecule such as biotin or gold, lectin binding can be easily identified using light and electron microscopy. In this chapter, we describe the appropriate experimental protocols for light and electron microscopic examination of lectin binding, emphasising their utility in characterising nephron segments in renal disease.

Lectin histochemical HPA-binding pattern of human breast and colon cancers is associated with metastases formation in severe combined immunodeficient mice

Metastasis formation is a major clinical problem in cancer treatment, and no significant progress in the treatment of metastatic spread has been made. This apparent lack of progress is partly caused by the absence of clinically relevant animal models of metastases. The binding of the lectin Helix pomatia agglutinin (HPA) has been associated with a poor prognosis in breast and colon cancer patients. HPA-positive and -negative human breast and colon cancer cell lines were transplanted into severe combined immunodeficient (SCID) mice. HPA-positive breast cancer cell lines (MCF-7 and T47D) metastasized in SCID mice, whereas the HPA-negative ones (BT20, HS578T and HBL100) did not. The HPA-positive colon cancer cell line HT29 metastasized, while the HPA-negative ones (COLO320DM, SW480 and SW620) did not. However, in two of eight SCID mice inoculated with the HPA-negative colon cancer cell line, CACO2 metastatic deposits were found. Despite this exception, HPA binding is a good indicator of the metastasis of human breast and colon cancer cells in SCID mice: 23 out of 26 HPA-positive cancers metastasized, as opposed to only two out of 38 HPA-negative cancers. This experimental model is well suited for investigating the functional role of carbohydrate residues recognized by HPA in breast and colon cancer metastasis.

The loss of lectin reactivity from human endometrium is a feature of malignant change

Changes in the cell surface glycoproteins were investigated in endometrial adenocarcinomas using eight biotin-labelled lectins (Con A, LCA, WGA, e-PHA, l-PHA, SBA, PNA, LTA) which select for the major classes of N-linked and O-linked oligosaccharides. The tissues studied were 14 normal endometria, 20 cases of simple hyperplasia and 30 endometrial adenocarcinomas. Sections were cut at 5 microns from formalin fixed paraffin embedded blocks and were stained with an avidin-peroxidase method. All normal and hyperplastic endometria contained the full range of expected saccharides (positive staining for Con A, LCA, WGA, SBA, PNA, LTA, e-PHA and l-PHA). By contrast, over half of the endometrial adenocarcinomas exhibited a loss of galactosamine (56.7%) and over a third of them failed to reveal galactose (36.7%) and fucose (30.0%) (negative staining for SBA, PNA and LTA, respectively). Interestingly, following neuraminidase treatment, galactose was identified in all adenocarcinomas studied, but the expression of galactosamine and fucose was unaffected. There was a discrete linear staining at the level of the basement membranes in a proportion of endometrial glands treated with e-PHA, l-PHA and LCA; this was continuous in normal and hyperplastic endometria, while it was fragmentary in endometrial adenocarcinomas. The loss of galactosamine reactivity from endometrial adenocarcinomas was significantly correlated with high grade differentiation, and also with the more frequent occurrence of a poor oestrogen (ER) and progesterone (PR) receptor status and with an unfavourable 5-year survival. No relationship was found between fucose reactivity and tumour differentiation, stage of disease, hormone receptor status or prognosis. It is concluded that galactosamine loss, together with reduced fucose expression, is a common feature of endometrial malignancy, and that galactosamine deficient tumours may reflect a more aggressive biological behaviour.

Ulex Europeus Agglutinin (UEA-I) lectin binding in breast carcinoma and its relationship to prognostic factors

In this study, lectin binding was compared with pathological prognostic factors and clinical follow-up details. Formalin-fixed, paraffin-embedded tissues from 43 cases of breast carcinoma were studied for binding with Ulex Europeus Agglutinin (UEA-I) lectin. Staining results were compared with tumor size, histologic and nuclear grade, lymph node status (number, capsular and pericapsular invasion), blood and lymphatic vessel invasion, ER and PR status, clinical stage and the patients' short-term follow-up details. Analysis of staining with UEA-I showed a significant relationship with blood vessel invasion (P < 0.01) and lymphatic vessel invasion (P < 0.05). Furthermore, PR showed a significant inverse correlation with lectin binding (P < 0.05). Staining with UEA-I related significantly with axilliary lymph node metastases (P < 0.05). UEA-I was positive in four (66.6%) out of six cases with distant organ mestastasis. This study confirms that, in breast cancer, lectin binding to the cancer cells can be a reliable indicator for axilliary metastases, and the need for additional therapeutic interventions.

Characterization of human ovarian epithelial tumors (ex vivo) by proton magnetic resonance spectroscopy

Proton magnetic resonance spectroscopy (1H MRS) offers an alternative investigational modality that will assist current pathologic techniques in the diagnosis of human ovarian epithelial tumors. Histologically normal human ovarian tissue (n = 12) was compared with ovarian benign fibromas (n = 3) and surface epithelial-stromal tumors (benign, n = 18; proliferating, n = 9; frankly malignant, n = 30) ex vivo by 1H MRS. The distinction between carcinomatous and benign or normal tissue (P<0.0001; Student's t-test) was made on one-dimensional (1-D) 1H MR spectra utilizing differences in resonance intensities of cellular lipid, creatine/phosphocreatine and lysine. The sensitivity and specificity of the test were 87% and 91%, respectively. Two-dimensional (2-D) MRS of carcinomatous biopsies showed multiple crosspeaks attributable to cell-surface fucosylation that correlated with tumor grade and loss of cellular differentiation. The multiple fucose crosspeaks were absent in spectra from normal ovary and benign tumors. The distinction between carcinomatous and normal or benign tissue based on MR-visible fucosylation gave a sensitivity and specificity of 88% and 97%, respectively. Proliferating tumors exhibited a range of cell-surface fucosylation patterns indicative of malignant potential.

Lectin histochemistry of normal and neoplastic peripheral nerve sheath. 2. Lectin binding patterns of schwannoma and neurofibroma

Lectin binding patterns of 31 schwannomas and 6 neurofibromas were examined using 12 lectins, and the results were compared with those of normal peripheral nerves. Tumors obtained from 10 cases of neurofibromatosis and 4 recurrent schwannomas were included. Changes of glycoconjugates were observed in association with a neoplastic transformation of Schwann cells; Arachis hypogaea (PNA) staining after neuraminidase treatment seen in normal Schwann cells was reduced in schwannoma of Antoni type A, and bindings with Glycine max (SBA) and Helix pomatia (HPA) after sialic acid removal, which were not seen in normal Schwann cells, appeared in schwannoma cells. Intensities of staining of tumor cells with each lectin were higher in Antoni type B than those in Antoni type A. No differences in lectin binding patterns were observed between schwannomas in patients with neurofibromatosis or recurrent schwannomas and ordinary, primary schwannomas in patients without stigmata of neurofibromatosis. Lectin binding patterns of Schwann cells and perineurial cells in neurofibroma were almost similar to those in normal peripheral nerves with an exception of faint stain of Schwann cells with HPA after neuraminidase pretreatment. This result suggests differences in extent of differentiation between schwannoma cells and neoplastic Schwann cells in neurofibroma. Specific PNA binding to perineurial cells in neurofibroma indicates the significance of this lectin as a marker of these cells.

Lectin binding patterns in normal liver, chronic active hepatitis, liver cirrhosis, and hepatocellular carcinoma. An immunohistochemical and immunoelectron microscopic study

We studied the binding patterns of 14 lectins in human normal and cirrhotic liver (LC) tissues and hepatocellular carcinomas (HCC) using the ABC method. Lectins were divided into 4 groups according to their binding patterns in normal tissues: (A) PHA, MPA, LcH, RCA-I, and WGA, which bound to hepatocytes and all three types of sinusoidal cells; (B) BPA, GS-I, PNA, and SBA, which bound to Kupffer cells and endothelia of interlobular arteries and veins and bile duct epithelia in the portal tract, but not to hepatocytes; (C) UEA-I, which bound only to endothelia of interlobular arteries and veins and bile duct epithelia in the portal tract; (D) LBA, Lotus, LPA, and SJA, which showed no binding. Thus group B lectins may be useful markers of Kupffer cells. Only electron microscopic examination revealed the precise binding sites of lectins in sinusoidal cells and hepatocytes. Hepatocyte cell surface polarities demonstrated by lectin binding in LC and HCC were different from those in the normal liver. The binding pattern of PHA to LC hepatocytes changed from a membranous to both a membranous and a cytoplasmic pattern, and that of LcH to HCC cells changed to dot-like staining in the cytoplasm. These changes of polarities in LC and HCC might be caused by changes in the distribution of lectin-binding carbohydrates or by the altered glycosylation of glycoconjugates.

Assessment of milk fat globule membrane antibodies and lectins as markers of short-term prognosis in breast cancer

The milk fat globule membrane antibodies HMFG1, HMFG2, NCRC 11 and four of the Mam 6 series, and the lectins peanut agglutinin, wheat germ agglutinin, Concanavalin A, Lotus tetragonolobus and Ulex europaeus I have been applied to 115 stage I and II breast carcinomas (median follow up = 36 months) to assess their value as prognostic markers. Of the milk fat globule membrane antibodies only NCRC 11 staining showed a relationship to development of recurrent disease and overall survival, but this did not act as an independent indicator over and above that provided by histological grade. None of the lectins gave prognostic information, including those whose binding related to node status or grade. It is concluded that for short-term prognosis none of the markers can given independent prognostic information over and above that provided by histological evaluation.

Differences in lectin binding patterns of normal endometrium and endometrial adenocarcinoma, with special reference to staining with Ulex europeus agglutinin 1 and peanut agglutinin

Differences in glycoconjugate composition between proliferative endometrium and endometrial adenocarcinoma were investigated by histochemical techniques using seven different lectins as probes. For light microscopy, the avidin-biotin-peroxidase complex (ABC) method was used. Concanavalin A (Con A), wheat germ agglutinin (WGA), and Ricinus communis agglutinin (RCA) stained almost all glandular cells in both proliferative (normal) and malignant endometria. Ulex europeus agglutinin 1 (UEA-1) strongly stained cancer cells, especially well-differentiated adenocarcinoma, but it scarcely stained normal endometrium. Peanut agglutinin (PNA) binding sites were observed only along the apical surface of normal endometrial glands, while the cytoplasm of endometrial adenocarcinoma cells was often positive for PNA. Soybean agglutinin (SBA) faintly reacted with proliferative endometrium and occasionally with malignant cells. Dolichos biflorus agglutinin (DBA) slightly stained proliferative and malignant endometria. By electron microscopic examinations using horseradish peroxidase (HRP)-labeled lectins, we observed that UEA-1, PNA, and Con A stained the Golgi membranes and plasma membrane of carcinoma cells. In addition, the Con A reaction was positive in the endoplasmic reticulum and nuclear envelope. These results revealed the differences in oligosaccharide chains between normal and malignant endometria, suggesting that UEA-1 and PNA, in particular, may be useful indicators of malignancy of the endometrium.

The use of lectins in histopathology

Lectins are proteins and glycoproteins extracted predominantly from plants which have the capacity to bind sugars specifically. This property makes them of interest for histopathology since they will bind to saccharides forming parts of glycoproteins and glycolipids of tissue constituents. Lectins have and can be used as reagents for mucin histochemistry, to identify specific cells, in the recognition of glycoprotein alterations in disease states, in studies of infectious diseases, and in the assessment of glycoconjugate alterations occurring with malignancy. They can be used for both light microscopic and ultrastructural localisation and various methods are available. It is important though, to consider the nature of the glycoconjugates under study and select lectins appropriately because of their varying specificities and binding characteristics. A panel of lectins should be used to study a particular configuration. Care should be taken with tissue fixation and processing. It must be remembered that an open and critical mind should be kept concerning interpretation of results. At the present time lectins have a limited value diagnostically, but the binding of Ulex europeus agglutinin to endothelium is certainly of value.

Binding of anti-EMA, AGF 4:48 and the lectin UEA-1 to human ovarian carcinomas: histological and clinical correlations

The staining reactions of the monoclonal antibodies anti-EMA, AGF 4:48 and the lectin UEA-1 from Ulex europaeus were investigated in formalin-fixed, paraffin-embedded sections of 36 primary ovarian carcinomas. The staining patterns were graded and related to tumour type, differentiation, FIGO stage and patient survival. Both antibodies and UEA-1 showed variations in their staining between and within tumours. The staining of mucinous tumours using anti-EMA was significantly less than in non-mucinous tumours. No other significant associations were found between staining grade and the different variables under study. The variations in staining were not demonstrated to have any prognostic significance.

Studies of lectin binding to the human cervix uteri: II. Cervical intraepithelial neoplasia and invasive squamous carcinoma

The cell surface carbohydrate profile of formalin-fixed paraffin-embedded tissue sections of neoplastic cervical squamous epithelium was evaluated using lectins of Bauhinia purpurea (BPA), Canavalin ensiformis (Con A), Griffonia simplicifolia I (GS I), Griffonia simplicifolia II (GS II), Maclura pomifera (MPA), Archis hypogaea (PNA), Glycine max (SBA), Ulex europaeus I (UEA I) and Triticum vulgaris (WGA). Three lectins (BPA, Con A and PNA) showed a similar pattern of staining in both normal squamous epithelium and in cervical intraepithelial neoplasia (CIN). Variable alterations were seen in lectin-binding patterns in CIN with seven lectins (GS I, GS II, MPA, PNA, SBA, UEA I and WGA). A significant difference was seen between the intensity of staining of normal squamous epithelium and CIN with all lectins except WGA. The alteration in GS II-binding pattern and intensity was significantly related to grade of CIN. No correlation was found between lectin binding and the presence of koilocytes in squamous epithelium. Cases of invasive squamous carcinoma showed a heterogeneous lectin-binding pattern and no significant association was found between lectin binding and tumour differentiation of patient survival. These results indicate that neoplasia in cervical squamous epithelium is associated with alterations in terminal alpha-Man residues, alpha- and beta-GalNAc residues, alpha- and beta-GlcNAc residues, alpha- and beta-Gal residues, and alpha-Fuc-containing residues, present in the outer parts of both N-linked and O-linked glycoconjugates. The implications of these findings are discussed.

The binding of peroxidase-labelled lectins to human endometrium in normal cyclical endometrium and endometrial adenocarcinoma

The nature of endometrial glycoconjugates throughout the menstrual cycle was investigated using a panel of lectins directed against specific sugar groups. This approach was also applied to a series of endometrial adenocarcinomas the findings for which were compared with those of normal controls. A change in the expression of glycosubstances was found in relation to the phase of the menstrual cycle; that there was increasing sialylation of terminal galactose groups during the secretory phase. This change may be influenced by progesterone. One group of endometrial adenocarcinomas exhibited binding patterns similar to those seen in secretory endometrium and this may be related to progesterone receptor state. Expression of fucose containing glycosubstances was identified in half of the carcinomas but not in the normal control tissue, thus indicating that a change in fucosylation occurs with endometrial neoplasia. None of the lectin binding patterns, however, correlated with variables in the patients themselves or within the tumours.

Analysis of glycoproteins released from benign and malignant human breast: changes in size and fucosylation with malignancy

Radiolabelled glycoproteins released into media from benign and malignant human breast tissue after 48 h organ culture have been analysed using SDS polyacrylamide gel electrophoresis and fluorography. Major differences were identified between benign and malignant tissues: (i) a considerably higher incidence of glycoproteins in the molecular weight range 210-280 kDa detected from carcinomas than benign samples, with incidence being greater in poorly differentiated tumours; (ii) fucosylation of these glycoproteins released from carcinomas but not benign breast; (iii) heterogeneity, particularly of fucosylation, between the carcinomas but consistency amongst benign breast. A glycoprotein of MW 230 kDa was of particular interest since it was not detected from any benign samples but was present in 11 of 17 carcinomas, when it was almost always fucosylated. This could prove to be a useful tumour marker.

Lectin histochemistry of the thyroid gland

The authors carried out a histochemical study with lectins (Ulex europaeus agglutinin-I [UEA-I], Triticum vulgaris [WGA], Glycine max [SBA], Dolichos biflorus [DBA], and Arachis hypogaea [PNA]) in different thyroid gland conditions (17 benign nodular goiters, three diffuse hyperplasias, five Hashimoto's thyroiditis, 20 follicular adenomas, 14 well-differentiated papillary carcinomas, five well-differentiated follicular carcinomas, and 30 normal thyroids) in order to determine if specific lectin patterns are developed during neoplastic transformation. The results showed that (1) in normal thyroid glands, the lectin, UEA-I, is able to discriminate between follicular cells and C-cells; (2) pathologic follicular epithelium had an increased expression of UEA-I, SBA, and WGA receptors; (3) no lectin or group of lectins allow a distinction between follicular carcinoma and papillary carcinoma; (4) when benign and malignant tumors are compared for UEA-I affinity there is a significantly greater frequency of malignant tumour with UEA-I receptor; and (5) although all investigated lectins have shown receptors in endothelial cells at least in one case, the most constant findings have been obtained with UEA-I and WGA. These findings suggest that lectins are not useful in routine diagnostic pathologic examination; however, in particular cases of follicular carcinoma, UEA-I may be a useful tool for the recognition of small vessels invaded by tumoral cells and the demonstration of fucose residues in malignant tumor cells.

Lectin binding in the male breast

Twenty-four male breast lesions including ten normal, ten gynaecomastia, and four infiltrating carcinomas were studied for the presence and distribution of lectin binding carbohydrates. For comparison, tissue sections of five normal female breast lesions, ten each of fibrocystic disease, fibroadenoma, and carcinoma, were also included in this study. Formalin-fixed, paraffin-embedded tissues were tested with Glycine maximus (SBA), Dolichos biflorus (DBA), Triticum vulgaris (WGA), Concanavalia ensiformis (Con A), Lotus tetragonolobus (LTA), Arachis hypogaea (PNA), and Bandeiraea simplicifolia (BSAI). The lectin-binding patterns were similar in normal, gynaecomastia, and carcinoma, and were not pathognomonic to any male breast lesion. These lectin reactive patterns in the male breast appear to be similar to those reported for the female breast lesions.

The distribution of lectin receptor sites in human breast lesions

Conflicting data regarding the status of A, B, H and T antigens in epithelium of normal, mastopathies, fibroadenomas and carcinomas of the breast stimulated us to re-examine the carbohydrate residues in these condition. Currently, we extended the number of carbohydrate residues studied by using ten different biotinylated lectins as probes and avidin-biotin-peroxidase complex (ABC) as a visualant. In addition, the pattern of lectin staining of cancerous cells in primary and metastatic sites was compared. In primary and metastatic breast carcinomas, lectin receptor sites were stained more intensely with Concanavalia ensiformi agglutinin (*Con A), Ricinus communis agglutinin-I (RCA-I) and wheat germ agglutinin (WGA), than in normal breast, in mastopathies or in fibroadenomas. Cryptic receptor sites for peanut agglutinin (PNA) were stained in all cases of breast carcinomas, while free PNA sites stained only in a few cases of well-differentiated carcinomas. Receptors sites for Ulex europaeus agglutinin-I (UEA-I) stained non-malignant epithelium of patients with blood group H but did not stain malignant cells. The results show significant differences in lectin-binding patterns and staining intensities between normal and non-malignant, and malignant epithelial breast cells. Furthermore, these results indicate that in malignant cells, there is an increased content of sialic acid-rich carbohydrates but not of asialylated glycoconjugates.

Expression of epithelial membrane and 3-fucosyl-N-acetyllactosamine antigens in cervix uteri with particular reference to adenocarcinoma in situ

The staining patterns obtained with antiepithelial membrane antigen (anti-EMA) and the monoclonal antibody to 3-fucosyl-N-acetyllactosamine (AGF 4:48) in the uterine cervix in intraepithelial and invasive neoplasia were compared to determine a possible role in differential diagnosis of reactive and neoplastic conditions. Both early invasive and in situ adenocarcinoma stained equally intensely with both agents and both antibodies stained diffusely tubal metaplasia, endometrial lined glands, and even occasional areas of normal endocervical mucosa. It is concluded that these agents are unlikely to be of use in the routine histological differentiation of glandular and squamous cervical dysplasia or neoplasia, but immunostaining with anti-EMA may help differentiate between reactive and metaplastic changes in endocervical glands and adenocarcinoma in situ.

Analysis of differentiation and transformation of cells by lectins

During differentiation cells are known to change their biological behavior according to their genotype. This is thought to be accompanied by a modulation of cell surface determinants expressed on the outer cell membrane. Vice versa, cell surface molecules are suggested to mediate extracellular signals to the genome. Most of these molecules integrated in the cell membrane have been proven to be glycoconjugates. The carbohydrate moieties of these molecules can be detected by means of lectins that are characterized by their ability to react specifically with distinct terminal sugar sequences. Thus, lectins have been used as appropriate tools for studying the modulation of functionally important membrane-associated molecules during the differentiation of cells, in particular of B- and T-lymphocytes. Moreover, lectins have been proven to distinguish between differentiated cells and malignant cell clones, according to the hypothesis that transformed cells possess a glycoconjugate profile that corresponds to the stage of differentiation at which they are arrested. Since lectins, like monoclonal antibodies, make it possible to study functionally important molecules that are associated with differentiation and malignancy, they might be of value for diagnostic purposes and, moreover, for analyzing malignant transformation.

Histochemical study of lectin binding in neoplastic and non-neoplastic urothelium

A histochemical study of lectin binding was performed to assess staining with lectins and, therefore, the expression of complex carbohydrates in human neoplastic urothelium. Forty-seven patients with transitional cell carcinoma of the bladder and six controls were studied. Cryostat sections were stained with a panel of 10 biotinylated lectins by means of the avidin-biotin-peroxidase technique. Sixteen tumours were also studied after conventional formalin fixation and paraffin embedding. In general, staining by lectins of tumours was more intense than staining of control urothelium and staining of tumours invading bladder muscle was greater than that of superficial tumours (both P less than 0.001). A small but statistically significant diminution of staining was observed after formalin fixation and paraffin embedding (P less than 0.05). Four lectins--Bandeiraea simplicifolia (P less than 0.01), Vicia villosa (P less than 0.01), peanut agglutinin (P less than 0.001) and soyabean agglutinin (P less than 0.001) stained invasive tumours more frequently than superficial tumours in frozen sections. Thus, increased binding of certain lectins was found in human transitional cell tumours and correlated with muscle invasion and poor differentiation.

Helix pomatia and Ulex europeus lectin binding in human breast carcinoma

Formalin fixed, paraffin embedded tissue from 100 consecutive cases of breast carcinoma were studied for binding with Helix pomatia (HPA) and Ulex Europeus (UEA1) lectins. Serial sections were pretreated with trypsin or neuraminidase to determine the effect of these enzymes on lectin binding. The lectins were visualized by the peroxidase antiperoxidase technique and the cell staining proportion assessed in a semi-quantitative manner under the light microscope. Correlating staining with prognostic factors and patient follow-up details showed that UEA1 related to disease-free interval and survival, and HPA to lymph node stage, time to loco regional recurrence and to survival. Relationships with both lectins were abolished by pretreatment with neuraminidase. The study demonstrates that a simple assessment of lectin binding can provide prognostic information in breast cancer. This may be useful particularly when conservational surgical practice restricts the amount of nodal tissue for staging.

The utilization of [3H] sugars by non-malignant and malignant human breast

The utilization of [3H] sugars and leucine by non-malignant and malignant human breast has been assessed using an organ culture technique with subsequent tissue autoradiography. The uptake of sugars by normal and hyperplastic breast was generally constant, with some differences observed in the utilization of galactose by acini of normal and hyperplastic tissues. After 24 h incubation localization was predominantly at the luminal cell periphery. The utilization of sugars by carcinomas was much more variable. Differences were observed between adjacent cells and cell groups of the same tumour. The uptake of individual sugars within a carcinoma was also varied being either similar to, or greater or lesser than normal breast. Variation between carcinomas was also present. No correlation between type and differentiation was noted in this respect, but there was between localization of sugars and differentiation. Better differentiated areas in tumours showed patterns similar to non-malignant breast whilst localization in poorly differentiated cell groups was cytoplasmic. The uptake of leucine was more constant and proved to be a useful indicator of viability. While this approach cannot give information with regard to differences in glycoprotein structure between non-malignant and malignant breast, it has been of value in determining the heterogeneity of tumour cells with regard to the enzymes involved in glycosylation. As such it would be of use in assessing the uniformity of response to agents modifying glycosylation.

The expression of fucosylated type 2 blood group chains in human breast and their significance

Monoclonal antibodies directed against O(H) blood group antigen and 3-fucosyl-N-acetyllactosamine have been used to investigate the incidence and significance of these type 2 blood group chains in non-malignant and malignant human breast tissue. The findings have been compared with those obtained with the fucose-binding lectins, Ulex europeus I and Lotus tetragonolobus. The expression of O(H) antigen in non-malignant breast is heterogeneous and shows no relationship to blood group status. Its expression in carcinomas shows no relationship to prognostic parameters such as differentiation and node status, whereas loss of Ulex europeus I binding is related to metastasis. The presence of 3-fucosyl-N-acetyllactosamine is limited in non-malignant breast, apart from pregnancy, but in carcinomas shows a relationship to differentiation, a feature not seen with fucose-binding lectins. It is apparent that to obtain the maximum amount of information about the modifications occurring in fuco-substances that appear to be of significance in breast malignancy, it is important to use monospecific probes as well as reagents with broader specificities, such as lectins.

Expression of the antigen detected by the monoclonal antibody Ca 19.9 in human breast tissues

The incidence and significance of the expression of the antigen defined by the monoclonal antibody Ca 19.9 (Sialyl Lea) has been assessed in human breast tissue. Frozen and formalin-fixed, paraffin embedded specimens of normal, hyperplastic, pregnant breast and carcinomas were examined using an immunoperoxidase technique. Ductal and acinar epithelium of normal and hyperplastic tissues showed variable reactivity in frozen sections but there was a reduction in staining in comparable samples after fixation and processing, such that in many instances only focal ductal epithelium reacted. A distinctive feature in the pregnant breast was the absence of staining in acini showing differentiated secretory activity, despite a reaction in adjacent nonsecretory acini and ducts. The overall incidence of detection of the Ca 19.9 antigen in breast carcinomas was 62%, but in half of these only a small number of cells stained. A significant relationship between expression of Sialyl Lea and poor differentiation of carcinomas was identified, but there was no correlation with local lymph node status. In contrast to the non-malignant tissue fixation and processing had little effect on the reactivity of carcinomas. It is suggested that this difference may be quantitative in nature, with malignant breast showing much greater expression, or be related to organisation of the antigen. The observations concerning carcinomas and pregnant breast indicate that the synthesis of the Ca 19.9 antigen is related to the state of differentiation and functional activity of human breast.

Ulex europeus I--peroxidase as a marker of vascular endothelium: its application in routine histopathology

Peroxidase-labelled Ulex europeus I lectin has been applied to a series of routinely fixed and processed vascular lesions to assess its value in the identification of endothelium. A group of breast carcinomas previously examined for binding of the lectin to the tumour have been re-assessed for evaluation of the use of Ulex europeus I in the determination of vascular invasion. There was consistent binding to normal vascular endothelium but this could be variable, there being stronger reactivity in small vessels of some tissues. All benign lesions stained showed clear definition of vascular channels but angiosarcomas were much less consistent in their staining reaction and the peroxidase-labelled lectin was considered to be a less satisfactory marker. Lymphatic endothelium was always negative; this proved to be a useful feature in differentiating between blood vessel and lymphatic invasion by breast carcinoma. Ulex europeus I-peroxidase could certainly have a role in routine histopathology in this area.

Lectins

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