Loss of basal cell phenotype with acquisition of lung-colonizing capability in mouse mammary tumors

Summary A transplantable pregnancy-dependent mouse mammary tumor, TPDMT-4, and its ovarian-dependent (T4-OR26) and autonomous (T4-OI96, T4-OI145, T4-OI165, T4-OI320 and T4-OI320CY) sublines were examined immunohistochemically for the expression of keratin 14 and type IV collagen. T4-OI96, T4-OI145, and T4-OI165, but not T4-OR26, T4-OI320, or T4-OI320CY, formed lung colonies (metastasis) after intravenous injection as a single-cell suspension. Despite the similar morphology of TPDMT-4 and its six sublines, only TPDMT-4 and the nonmetastatic sublines revealed a basal cell phenotype as defined by keratin 14 expression. Staining for type IV collagen was complete at the peripheries of the glandular structures in TPDMT-4 and nonmetastatic sublines but was patchy in the metastatic tumors.     

Cell surface glycosylation changes accompanying immortalization and transformation of normal human mammary epithelial cells

Fluorescent lectin binding to cell surfaces was quantitatively analysed by flow cytometry on mortal human breast epithelial cells MCF-10M, the immortalized cell line MCF-10A derived from MCF-10M and sublines of MCF-10A transfected with the neomycin resistance gene (MCF-10Aneo), the c-Ha-ras protooncogene (MCF-10AneoN), or transfected and transformed with the c-Ha-ras activated oncogene (MCF-10AneoT). Immortal MCF-10A cells bound 10-fold more peanut agglutinin (PNA) and soy bean agglutinin (SBA) than did MCF-10M cells. Transformed MCF-10AneoT cells bound approximately ten times more PNA than did non-transformed cells transfected with protooncogene (MCF-10AneoN). Treatment of the transfectants with neuraminidase abrogated the differences in PNA-binding and reduced the differences in SBA binding. SDS-PAGE separation of PNA binding glycoproteins revealed different patterns for all MCF-10A derived sublines.     

Tissue binding of lectins in disorders of the breast

Twenty breast lesions including seven scirrhous ductal carcinomas, one infiltrating lobular carcinoma, one colloid carcinoma, four fibroadenomas, and seven cases of fibrocystic disease were analyzed by fluorescence microscopy for the presence and distribution of lectin-binding carbohydrates. Paraffin-embedded tissue sections were tested with wheat germ agglutinin (WGA), Ricin communis agglutinin I (RCA I), peanut agglutinin (PNA), Soybean agglutinin (SBA), Dolichos biflorus agglutinin (DBA), Ulex europaeus agglutinin I (UEA I), and concanavalin A (Con A). Brightest and most consistent staining regardless of the nature of the breast lesion was obtained with WGA followed in approximate order of staining intensity by RCA, PNA, SBA/DBA and Con A. UEA I stained many of the benign breast lesions but no malignant lesions. Lectin binding carbohydrate in benign lesions was localized mainly along the apices of mammary epithelial cells but there was considerable variation in staining patterns among malignant tumors. The fluorescence microscopic arrangement of lectin binding carbohydrate appears distinct for each malignant neoplasm of breast but is more consistent in benign conditions.     

Differences in metallothionein expression in transplantable mouse mammary tumor lines.

In order to elucidate a possible role of metallothionein (MT) in mammary carcinogenesis, MT and sex hormone receptor (estrogen receptor, ER; progesterone receptor, PR) expressions were investigated immunohistochemically in a transplantable pregnancy-dependent mouse mammary tumor (TPDMT-4) and related autonomous tumor sublines (T4-OI96, T4-OI165 and T4-OI320CY) recovered from pregnant and virgin DDD mice. TPDMT-4 showed MT expression in tumor cells, while the expression was less evident in T4-OI165 and T4-OI96 among the autonomous tumor lines; in T4-OI320CY, the MT expression was similar to that in TPDMT-4. Chromatographic study of MT contents in the tumor lines confirmed the results of the immunohistochemical examination. PR and ER were localized in the tumor cells of TPDMT-4, but not in those of autonomous tumor sublines. In TPDMT-4, a significant correlation was observed between MT and ER expressions (r = 0.83, P < 0.01), but not between MT and PR expressions (r = 0.26, P > 0.4), also between MT expression and mitotic activity (r = -0.34, P > 0.3). Since T4-OI96 and T4-OI165 are known to be more malignant than T4-OI320CY, the present study indicates a negative correlation between the MT positivity and progression of the transplantable mammary tumor in mice.     

Lectin binding sites of cultured ovarian Sertoli cell tumors and follicular granulosa cells

A panel of seven alkaline phosphatase labeled lectins was used to probe nitrocellulose electroblots of SDS-PAGE separated proteins from a primary culture of normal ovarian granulosa cells and an ENU-induced Sertoli cell tumor cell line (SCTL-I). Several additional lectin binding proteins were observed in silver stained SDS-PAGE gels as well as with lectins in SCTL-I. Succinated concanavalin A (Suc. Con A), Ricin communis agglutinin (RCA-I), Ulex europaeus agglutinin (UEA 1), Soybean agglutinin (SBA), Dolichos biflorus agglutinin (DBA) and Peanut agglutinin (PNA) stained more intensely in SCTL-I than normal granulosa cells. The same lectins as above, labeled with fluorescein isothiocyanate (FITC), were used to study the distribution of specific binding sites of tissue cultured cells grown in chamber/slides. Both normal ovarian granulosa cells and SCT cells exhibited strong peninuclear cytoplasmic labeling with Con A UEA-1 and WGA exhibited predominantly a nuclear and granular cytoplasmic staining pattern. SBA and DBA exhibited a strong coarse granular cytoplasmic labeling in granulosa cells and moderate granular cytoplasmic in SCT cells. In granulosa cells, Golgi regions stained strongly with PNA but weakly in SCT cells. RCA-I staining was negative in both cultures. Labeling of tissue cultured cells with lectins provides more details than histological sections of lectins binding sites at cellular structural levels.     

Heterogeneity in surface antigen of cell lines and clones from a murine carcinoma

Cell lines of the murine Lewis lung tumor (3LL) were established from primary tumor site (PT) and from lung metastatic foci (Met). Expression of histocompatibility antigens was assessed by immunofluorescence with an anti-H-2b antibody and by tumorigenicity of the cells in different strains of mice. Analysis for tumor-associated transplantation antigens (TATA) were performed by challenging mice with living tumor cells after pretreatment with irradiated cells or by in vivo tumor neutralization assays with different tumor cells as target cells and T lymphocytes from immunized animals as effector cells. The 3LL tumor was found to be heterogeneous in respect to tumor growth rate in vivo, metastatic capacity in vivo, expression of normal histocompatibility antigens and expression of "TATA". Moreover, monoclonal antibody B1 (H11-115) binding to a Met cell surface antigen, but not to normal cells, was obtained. The antibody bound to 3LL tumor cell lines from primary tumor (PTH, PTV), from a mixture of metastatic foci (MetH, MetV), from different metastatic foci originating from 3 different mice, and to 21 subclones derived from one of the lines established from a metastatic focus. Analysis of the 3LL sublines demonstrated a significant antigenic heterogeneity within each tumor population as well as among the different sublines.     

Lectin binding in murine tumour lines with different malignant characteristics. Effect of enzyme (pronase, neuraminidase) treatment on lectin labelling

We used 5 syngeneic murine tumour systems for studying quantitative lectin surface binding of intact viable tumour cells. We also investigated, for 3 of the tumours, whether the lectin binding sites were susceptible to proteolytic enzyme (pronase) or neuraminidase treatment. There were significant differences between two of the tumour lines in the binding of wheat germ agglutinin (WGA), concanavalin A (ConA). peanut agglutinin (PNA), soybean agglutinin (SBA) and Ulex europeus agglutinin (UEA). There were also variations in lectin binding between the other tumor lines, but these differences were not statistically significant. Lectin binding showed no evident relationship to the malignancy or the metastasis-forming capacity of the respective tumour cell line. Proteolytic treatment, which drastically affects intravenously induced experimental metastasis formation by one of the tumours, caused a decreased binding of SBA, ConA and WGA. Neuraminidase treatment increased both PNA and SBA binding in three different cell lines, presumably by removing sialic acid masking D-galactose and N-acetyl-D-galactose-amine groups.     

Heterogeneity of human natural killer cells with respect to lectin-binding ability

The binding ability of peanut agglutinin (PNA), lentil agglutinin (LEN), soybean agglutinin (SBA), wheat germ agglutinin (WGA), and asparagus pea agglutinin (ASP) to human natural killer (NK) cells with the use of the double-marker immunofluorescence technique was studied. For identification of NK cells, VEP 13 (DC 16) monoclonal antibody was used. The receptor for PNA lectin was shown exclusively after neuraminidase treatment of cells, and VEP 13 antigen was neuraminidase resistant. The majority of VEP 13+ cells showed coexpression of lectin receptors for PNA, LEN, and WGA. Our results suggested that VEP 13 antigen and PNA receptor are two distinct membrane structures, whereas there is some competitive binding between LEN as well as WGA lectin and VEP 13 antibody. In double-marker experiments using PNA and LEN lectin, the small fraction of VEP 13+ cells lacking receptors for these lectins was found. In spite of neuraminidase treatment of the cells, no binding of SBA and ASP was shown. These results indicated apparent heterogeneity of NK cells with respect to lectin receptor expression. WGA lectin, which bound to all VEP 13+ cells, could probably be useful for isolation of NK cells.     

Progression toward metastatic phenotype with loss of growth-inhibiting tumor-cell/cell interactions in vivo

Five autonomous sub lines, T4-O1320, T4-O1320CY, T4-O1165, T4-O1145 and T4-O196, were established from the transplantable hormone-dependent mouse mammary tumor, TPDMT-4, by pass aging under different conditions. These autonomous tumors were characterized by rapid growth in DDD virgin mice and the parental TPDMT-4 by no growth in these mice. Thus, 10⁵ T4-O1320, 2 × 10⁴ T4-O1320CY, 2 × 10³ T4-O1165, 2 × 10³ T4-O1145 and 10³ T4-O196 cells were co-injected with 5 × 10² TPDMT-4 cells into virgin mice to determine whether or not hormone-dependent tumor cells influence the growth of autonomous tumor cells. TPDMT-4 cells retarded the growth of T4-O1320 and T4-O1320CY tumors but accelerated that of T4-O1165, T4-O1145 and T4-O196. Irradiated TPDMT-4 cells stimulated the growth of all the sub lines except T4-O1320. In 3-dimensional collagen-gel culture, T4-O1320 and T4-O1320CY cells formed branched or stellate structures similar to normal mammary glands, as did TPDMT-4, but T4-O1165, T4-O1145 and T4-O196 cells grew as rounded masses with knobs and showed a completely different morphology. T4-O1165, T4- O1145 and T4-O196 cells, but not the others, had lung-colonizing ability. Chromosomal aberration was found in T4-O1320CY and T4-O196 but not in the others. Thus, the susceptibility of autonomous sub line tumor cells to growth-inhibitory regulation from the parental hormone-dependent tumor cells correlated well with growth morphology within collagen gels and meta-static ability, but not with chromosomal aberration. The results suggest that meta-statically-competent tumor-cell variants, once they appear, may have a growth advantage in hormone- dependent mammary tumors. © 1995 Wiley-Liss, Inc.     

Lectin histochemistry of adenomatous polyps. Not a predictor of metachronous lesions

The binding characteristics of fluorescein isothiocyanate conjugated lectins to normal colonic mucosa, and 43 adenomatous polyps were studied by fluorescence microscopy. The lectin, Dolichos biflorus agglutinin (DBA) stained intensely to upper crypt cells of the sigmoid colon and rectum but to a lesser degree to proximal colonic crypts or lower crypt cells distally. Peanut agglutinin (PNA) and Ulex europaeus agglutinin (UEA) did not bind to the theca of proximal or distal colonic crypts. The lectin Griffonia simplicafolia agglutinin (GSA1) bound intensely to upper and lower crypt cells of both regions. PNA binding was noted in 56% of adenomatous polyps, occurred more often in polyps of the distal colorectum, and increased with polyp size and villous histology. UEA bound to 26% of adenomatous polyps, 42% of proximal polyps, and 17% of distal polyps. DBA staining was noted in 72% of polyps without regional preference. GSA1 stained all polyp specimens. To determine if the lectin binding characteristics of an index (initial) polyp might serve as a predictor of metachronous lesions, 20 patients (29 polyps) without a history of polyps or cancer and who had at least one surveillance colonoscopy 1 to 3 years after the initial polypectomy were studied. The presence or absence of PNA, UEA, or DBA binding in an index polyp did not predict the occurrence of metachronous lesions. Five of the six patients with more than one index polyp had metachronous polyps at follow-up surveillance colonoscopy.     

Histochemical study of colorectal adenocarcinoma by fluorescein isothiocyanate (FITC) conjugated lectins

Binding of FITC conjugated lectins to mucin in benign and malignant colon lesions was studied by fluorescence microscopy. In 145 cases of colonic adenocarcinoma, PNA (peanut agglutinin) was found to be bound to 75% of cases, while DBA (dolichos biflorus agglutinin) to 13% only. By contrast, DBA was bound to 94% of normal colon mucosa, while PNA to 15% only. Chronic colitis, simple adenoma and inflammatory polyps had the same binding pattern as normal mucosa, but villous adenoma, mixed polyps and multiple polyposis which are considered as premalignant lesions in colon had high positive rate of PNA binding and low binding percentage of DBA. These results indicate that an exposed carbohydrate structure Gal B1-2----GlNAc is expressed in the mucin produced by colonic adenocarcinoma. Meanwhile, some normal mucin component disappears from the malignant colonic epithelium. The mechanism of alteration of human colonic mucin present in malignant transformation is briefly discussed.     

Heterogeneity of murine mammary adenocarcinoma cell subpopulations. In vitro and in vivo resistance to macrophage cytotoxicity and its association with metastatic capacity

Properties of Ts, a long-term tissue culture line of T1699 mammary adenocarcinoma of DBA/2 mice, and two of its sublines - TR2 and TLI-1-were comparatively studied. Ts tumors produced no spontaneous metastases, nor did i.v. injection of up to 1 X 10(6) Ts cells produce a lung tumor nodule. Ts cells were susceptible to macrophage cytotoxicity in vitro and i.v. injected cells were rapidly destroyed in the lungs. TLI-1 tumors spontaneously metastasized to the lungs, and i.v. injection of 1 X 10(3) TLI-1 cells produced approximately 15 lung nodules per animal. TLI-1 cells were least susceptible to both macrophage-mediated cytolysis in vitro and in vivo host antitumor mechanisms. TR2 cells were intermediate with respect to all these properties. Differences in their susceptibility to macrophage cytotoxicity were recognized not only by normal peritoneal macrophages but also by murine macrophage lines. On the other hand, all the subpopulations were uniformly resistant to NK activity in vitro. These findings suggest that resistance of tumor cells in vitro to macrophage cytotoxicity corresponds with their in vivo metastatic potential.     

Relationships between degree of binding,cytotoxicity and cytoagglutinating activity of plant-derived agglutinins in normal lymphocytes and cultured leukemic cell lines

PURPOSE: To clarify the relationships between the degree of lectin-cell binding, cytotoxicity and cytoagglutinating activity of plant-derived lectins in normal lymphocytes and cultured leukemic cell lines. METHODS: Plant lectins with different quaternary structures and saccharide specificity were used: Dolichos biflorus agglutinin (DBA), Soybean agglutinin (SBA) and Wheat germ agglutinin (WGA). The leukemic cell lines used were: Jurkat, MOLT-4, RPMI-8402, HPB-ALL, CCR-HSB-2 and BALL-1 (derived from acute lymphoblastic leukemia); Raji and Daudi (derived from Burkitt's lymphoma); K-562 (derived from myelogenous leukemia). The lectin-cell binding was detected microscopically and fluorimetrically using FITC-conjugated lectins. Cytotoxicity was estimated by the CellTiter-Glo luminescent cell viability assay, and cytoagglutinating activity by a spectrophotometric method. RESULTS: The binding of DBA and SBA to normal lymphocytes was negligible, while their binding to leukemic cells increased markedly with increasing lectin concentration. Analogous results were obtained for WGA. However, it was found that WGA also interacted to a significant degree with normal lymphocytes. The degree of lectin-cell binding increased in the order: DBA相似文献   

Progression from hormone dependence to autonomy and angiogenesis in mouse mammary tumours

The transplantable pregnancy-dependent mammary tumour (TPDMT-4), the related hormone-dependent (TPDMT-4EP) and autonomous (T4-0I320 and T4-0I96) subline tumours, and the mammary glands from DDD mice were compared for angiogenic activity on the rabbit cornea by tissue implantation. The TPDMT-4EP tumour was established by serially transplanting TPDMT-4 tumour fragments in oestradiol plus progesterone treated mice. The T4-0I320 and T4-0I96 tumours directly derived from the TPDMT-4 and TPDMT-4EP tumours, respectively. Angiogenic activity was graded by macroscopic and microscopic examinations into 3 classes; negative, partial and complete angiogenesis. These tumours were comparable to mammary glands in activity and induced complete angiogenesis in only 15-23% of the implants. However, when partial and complete responses were combined as positive angiogenesis, TPDMT-4, T4-0I320, TPDMT-4EP and T4-0I96 tumour implants were angiogenic in 25, 29, 42 and 54%, respectively. The T4-0I96 tumour was significantly more angiogenic than the parent tumour but this was not so for the TPDMT-4EP tumour. Spontaneous C3H mouse mammary tumours, human gliomas from nude mice, rat Walker 256 carcinomas and rabbit VX-2 tumours induced complete angiogenesis in 54, 63, 59 and 92% of the implants, respectively. The results suggest that the TPDMT-4 tumour is unique in being weakly angiogenic and able to progress toward greater autonomy with or without augmented angiogenic activity in different conditions.     

Tumor progression in vivo: increased soybean agglutinin lectin binding, N-acetylgalactosamine-specific lectin expression, and liver metastasis potential.

Tumors which grew out from threshold s.c. inocula of L5178Y-F9 and SL2-5 murine T-cell lymphomas in syngeneic DBA/2 mice exhibited a unified natural defense-resistant phenotype including an increased tumorigenicity and correlating reductions in susceptibility to natural antibodies, natural killer cells, and activated macrophages in vitro. The metastatic potential and cell surface saccharide expression of these cells were determined to assess the impact of growth from a small tumor focus in vivo on subsequent metastatic ability and to determine whether there was any association with changes in cell surface carbohydrates, which have been implicated now for many years in tumor development. A significantly increased liver-colonizing ability was observed following i.v. injection. The most consistent change in cell surface saccharide expression detected in studies using five lectins was an increase in N-acetyl-D-galactosamine (D-GalNAc)-specific soybean agglutinin (SBA) binding. The log of experimental liver metastasis, SBA binding, and the percentage of hepatocyte rosetting of the parental and in vivo-selected cells exhibited significant direct correlations. While inhibition of rosetting with in vivo-selected lines by D-GalNAc and galactose was consistent with the involvement of the D-galactose/D-GalNAc-specific hepatocyte receptor, preincubation of the tumor cells but not hepatocytes with D-GalNAc inhibited hepatocyte rosetting and D-GalNAc inhibited homotypic tumor cell binding. These data suggest a role for a saccharide-specific, lectin-like receptor on tumor cells in both interactions and therefore in the increased experimental liver metastasis. Furthermore, the increased expression of D-GalNAc-inhibitable SBA binding sites on the in vivo-selected variants should increase the homotypic binding by the D-GalNAc-specific lectin-like receptors on the tumor cells providing a rationale for the direct relationship observed between increased SBA binding and i.v. metastatic potential.     

Radioimmunodetection of murine mammary adenocarcinoma (TA3/Ha) lung and liver metastases with radioiodinated PNA

Organ-specific lung and liver metastatic variants of the murine TA3/Ha mammary adenocarcinoma cell line were selected by sequential in vivo growth with intervening in vitro cell culture. These variants readily formed specific lung or liver metastatic lesions upon i.v. injection into A/J mice. TA3/Ha cells produce a large cell surface glycoprotein called epiglycanin, which contains a high proportion of Thomsen-Friedenreich (TF) antigenic structures. The presence of non-cryptic TF has been associated with malignancy in humans and animals. We used peanut lectin agglutinin (PNA), which has a preferential affinity for TF antigenic structures, to determine whether these selected metastatic variants retained the TF antigen expression. In vitro, the TA3/Ha metastatic variant lines exhibited strong PNA binding similar to that seen with human RBC after neuraminidase treatment to expose the cryptic TF antigen. In contrast, the non-epiglycanin-producing TA3/St subline did not bind PNA appreciably. Autoradiography of liver sections with TA3/Ha metastatic lesions after 125I-PNA i.v. indicated an avid uptake throughout the viable tumor mass and FITC-PNA staining of these tissue sections readily identified the metastatic tumors under fluorescence microscopy. Tissue biodistribution studies revealed that lung or liver containing the TA3/Ha metastatic variant nodules retained about 7 to 8 times as much of an i.v. dose of radioiodinated PNA as did controls, allowing for clear delineation of tumor-infiltrated lung or liver by gamma scintigraphy. These in vitro and in vivo tests confirm that the selected organ-specific TA3/Ha variants retained the binding characteristics of the parent TA3/Ha line. These observations illustrate the potential utility of radiolabelled PNA for the detection of TF-antigen-expressing tumors and metastases. This murine system with organ-specific TA3/Ha metastatic variants also provides a model for evaluation of various other macromolecular probes for tumor radioimmunodetection of metastatic lesions.     

Involvement of soybean agglutinin binding cells in the lymphatic metastasis of the R3230AC rat mammary adenocarcinoma

Many human tumors, such as those of the breast, metastasize initially via the lymphatics. The tumor cell surface is believed to play a critical role in this process. To study the cell surface properties involved in dissemination, the poorly metastasizing R3230AC rat mammary adenocarcinoma was enriched for metastasizing cells by excising rare lymph node metastases arising after the s.c. injection of 10(6) cells and reinjecting these cells into another series of rats. By repeated enrichment cycles, the frequency of lymphatic metastasis was increased from 10 to 60-100% of the animals given injections. Fluorescein-conjugated lectins were used to probe the tumor cell surface. It was found that the percentage of cells in the population able to bind high levels of the lectin, soybean agglutinin (SBA), increased from 11 to almost 80% in the highly metastatic, enriched cell populations. A linear correlation (r = 0.92; P less than 0.001) was found between the percentage of cells in the population which bound high levels of SBA and the frequency of lymphatic metastasis in a series of enriched cell lines. Clones which bound high levels of SBA metastasized to lymph nodes at a high frequency, while clones which bound only low amounts of SBA exhibited a low frequency of lymphatic metastasis regardless of the metastatic potential of the cell line from which the clones were isolated. The binding of SBA to the cell was reduced by preincubation of the lectin with galactose, completely blocked by incubation with N-acetylgalactosamine, and unaffected by incubation with glucose or mannose, demonstrating that SBA was recognizing a N-acetylgalactosamine-containing component of the cell surface. Cells enriched for lymphatic metastasis were not similarly enriched for hematogenous metastasis. While cell lines enriched for lymphatic metastasis have been previously described, this is the first report of a specific cell surface property, SBA-binding, associated with lymphatic metastasis.     

Carbohydrate profiles shown by a lectin and a monoclonal antibody correlate with metastatic potential and prognosis of human lung carcinomas.

The expression of two carbohydrate markers--namely, 4C9 antigen, which is an Lex antigen, and the Dolichos biflorus agglutinin (DBA) binding site, which is an N-acetylgalactosamine marker--was examined histochemically in tumors and adjacent nontumorous tissues of 102 cases of human lung carcinomas. In nontumorous tissues, the DBA binding site was expressed more frequently than 4C9 antigen, and the DBA binding site had a tendency to be expressed more significantly than in tumor cells. Adenocarcinomas and well-differentiated tumors had a tendency to more cell surface staining. Patients with tumors that expressed DBA binding sites but not 4C9 antigen (4C9-, DBA+) had fewer metastasis and significantly better prognoses than patients with tumors of other carbohydrate profiles. Better prognosis of patients with 4C9-, DBA+ tumors was observed in those with blood group A antigen and those without it, and the better prognosis also was observed in patients with Stage I and IIIA disease.     

Lectin-binding characteristics of related high- and low-metastatic rat mammary adenocarcinoma cell lines

Lectin-binding characteristics of a previously described highly metastatic variant (clone 4), derived in vivo from a poorly metastatic rat mammary adenocarcinoma (DMBA-8), have been investigated. of the lectins studied clone 4 cells, unlike the parent cells, bound Ulex europaeus agglutinin (UEA-1; specificity alpha-L-fucose) and peanut agglutinin (PNA; specificity D-galactose). These differences may be related to the greatly enhanced ability of clone 4 cells to form lung foci after intravenous injection. After neuraminidase treatment the differential binding of PNA, as shown by flow cytofluorography, was abrogated whereas that of UEA was unchanged. After separation by SDS-PAGE, four proteins in total cell extracts of clone 4 cells bound 125I-UEA applied to the gels. These had subunit molecular weights greater than 100,000 daltons and were also found in cellular extracts of another highly metastatic rat mammary adenocarcinoma (MAT 13762-B), but were missing from DMBA-8 cell extracts. In clone 4 and MAT 13762-B cells exogenous 3H-fucose was mainly incorporated into four fucoproteins of similar molecular weights to those which bound 125I-UEA. DMBA-8 cells, which incorporated slightly less exogenous fucose, showed a different pattern of fucoprotein labelling, which would seem to explain why DMBA-8 cells failed to bind UEA. Differences in cell surface protein iodination patterns were also noted between DMBA-8 and clone 4 cells.     

Lectin binding to prostatic adenocarcinoma

The binding of different lectins (concanavalin A [Con A], triticum vulgaris [WGA], glycine maximum [SBA], dolichos bilflorus [DBA], ulex europaeus [UEA I], arachis hypogaea [PNA], and ricinus communis [RCA I]) to cells of normal prostate glands, hyperplastic glands and adenocarcinoma was studied. The Con A, WGA, DBA, PNA and RCA I bound to both normal and hyperplastic glands. The binding in the malignant glands differed from that of the benign conditions. The SBA, which was not bound by benign cells, was bound to the malignant glandular cells. Also, UEA I was bound to a part of the carcinoma cells. In addition, the binding pattern of Con A and WGA in the cells differed between the malignant and benign conditions. Based on the results of this study, it is suggested that lectin histochemical study might be useful in routine pathologic examination to detect malignant cells in cases which are doubtful with regard to malignancy by routine methods.