lewis-x-antigen and Melanoma

The aim of the present study was to immunohistochemically investigate the expression and prognostic significance of putative cancer stem cell markers CD117 (c-kit), CD34, CD20 and CD15 in a cohort of patients with primary choroidal and ciliary body melanoma.. The immunohistochemical expression of these markers was evaluated using 3,3'-diaminobenzidine tetrahydrochloride (DAB) and 3-amino-9-ethylcarbazole (AEC) chromogens on paraffin-embedded tissue samples from 40 patients who underwent enucleation in the period from 1985 through 2000. Thirty-one patients had adequate tissue specimens for the analysis.. CD117 overexpression was observed in 12 of the 31 samples (39%) when AEC chromogen was used and in 14 of 26 (54%) samples when DAB was used. CD15 positivity was seen in three out of 30 (10%) samples with AEC and in six out of 26 (23%) samples with DAB. CD20 and CD34 exhibited no positivity in the tested samples. During the average follow-up time of 8.7 years (range 0.5-22 years), 17 patients (55%) died due to metastatic disease. The Kaplan-Meier plots showed a significantly shorter overall and disease-free survival in CD117-positive patients when the AEC chromogen was used. CD15 expression was not associated with patients' survival. In multivariate analysis, patients expressing the CD117 AEC had 4.13 times higher risk of lethal outcome in comparison with CD117 AEC negative patients.. Our retrospective cohort study has for the first time demonstrated a small proportion of CD15-positive uveal melanomas. CD117 AEC overexpression was associated with a worse outcome in patients with choroidal and ciliary body melanoma. Further studies should confirm the validity of these observations and their potential for targeted treatment modalities.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Choroid Neoplasms; Ciliary Body; Disease Progression; Disease-Free Survival; Female; Fucosyltransferases; Humans; Immunohistochemistry; Kaplan-Meier Estimate; Lewis X Antigen; Male; Melanoma; Middle Aged; Neoplastic Stem Cells; Predictive Value of Tests; Proportional Hazards Models; Proto-Oncogene Proteins c-kit; Retrospective Studies; Risk Factors; Time Factors; Treatment Outcome; Up-Regulation; Uveal Neoplasms

Malignant melanoma is a destructive and lethal form of skin cancer with poor prognosis. An effective treatment for melanoma is greatly needed. Ginsenoside Rg3 is a herbal medicine with high antitumor activity. It is reported that abnormal glycosylation is correlated with the tumor cell growth. However, the antitumor effect of Rg3 on melanoma and its mechanism on regulating glycosylation are unknown. We found that Rg3 did not only inhibit A375 melanoma cell proliferation in a dose-dependent manner, but also decreased the expression of fucosyltransferase IV (FUT4) and its synthetic product Lewis Y (LeY), a tumor-associated carbohydrate antigen (TACA). Knocking down FUT4 expression by siRNA dramatically reduced FUT4/LeY level and inhibited cell proliferation through preventing the activation of EGFR/MAPK pathway. Consistently, the inhibitory effect of the Rg3 and FUT4 knockdown on melanoma growth was also seen in a xenograft melanoma mouse model. In conclusion, Rg3 effectively inhibited melanoma cell growth by downregulating FUT4 both in vitro and in vivo. Targeting FUT4/LeY mediated fucosylation by Rg3 inhibited the activation of EGFR/MAPK pathway and prevented melanoma growth. Results from this study suggest Rg3 is a potential novel therapy agent for melanoma treatment.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Down-Regulation; Fucosyltransferases; Ginsenosides; Humans; Lewis Blood Group Antigens; Lewis X Antigen; Male; MAP Kinase Signaling System; Melanoma; Mice; Mice, Nude; Skin Neoplasms; Xenograft Model Antitumor Assays

Abnormal glycosylation is catalyzed by the specific glycosyltransferases and correlates with tumor cell apoptosis. Increased fucosyltransferase IV (FUT4) is seen in many types of cancer, and manipulating FUT4 expression through specific signaling pathway inhibits cell growth and induces apoptosis. NF-κB is known playing a vital role to control cell growth and apoptosis. Ginsenoside Rg3 is an herbal medicine with strong antitumor activity through inhibiting tumor growth and promoting tumor cell death. However, whether Rg3-induced inhibition on tumor development involves reduced NF-κB signaling and FUT4 expression remains unknown. In the present study, we found that Rg3 suppressed FUT4 expression by abrogating the binding of NF-κB to FUT4 promoter through inhibiting the expression of signaling molecules of NF-κB pathway, reducing NF-κB DNA binding activity and NF-κB transcription activity. NF-κB inhibitor (Bay 11-7082) or knocking down p65 expression by p65 siRNA also led to a significant decreased FUT4 expression. In addition, Rg3 induced apoptosis by activating both extrinsic and intrinsic apoptotic pathways. Moreover, in a xenograft mouse model, Rg3 downregulated FUT4 and NF-κB/p65 expression and suppressed melanoma cell growth and induced apoptosis without any noticeable toxicity. In conclusion, Rg3 induces tumor cell apoptosis correlated with its inhibitory effect on NF-κB signaling pathway-mediated FUT4 expression. Results suggest Rg3 might be a novel therapy agent for melanoma treatment.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Binding Sites; Cell Line, Tumor; Cell Survival; Fucosyltransferases; Gene Expression Regulation, Neoplastic; Ginsenosides; Humans; Lewis X Antigen; Male; Melanoma; Mice; NF-kappa B; Promoter Regions, Genetic; Signal Transduction; Skin Neoplasms; Xenograft Model Antitumor Assays

Members of the family of carcinoembryonic antigen (CEA)-related cell adhesion molecules (CEACAMs) belonging to the immunoglobulin (Ig) superfamily are expressed in a variety of normal and malignant human tissues. As components of the cell membrane, these glycoproteins can make contact with adjacent cells. CEACAM1 and CEACAM5 (CEA) express Lewis(x) (Le(x)) structures. As shown by mass spectrometry in conjunction with enzymatic digestion, CEACAM1 contains at least seven Le(x) residues. Fucosyltransferase IX is the main fucosyltransferase responsible for attachment of terminal fucose, the key feature of the Le(x) structure, to CEA and CEACAM1. The Le(x) residues of both, CEACAM1 and CEA, interact with the human Le(x)-binding glycan receptors DC-SIGN and SRCL. Since subpopulations of human macrophages express DC-SIGN or SRCL, Le(x)-carrying CEACAMs may modulate the immune response in normal tissues such as the human placenta or in malignant tumours, for example in colorectal, pancreatic or lung carcinomas.

Topics: Antigens, CD; Carcinoembryonic Antigen; Cell Adhesion Molecules; Cell Line; Collectins; Colorectal Neoplasms; Female; Fucose; Fucosyltransferases; Humans; Intestinal Mucosa; Lectins, C-Type; Lewis X Antigen; Melanoma; Placenta; Polysaccharides; Pregnancy; Protein Binding; Receptors, Cell Surface; Receptors, Scavenger; Recombinant Proteins; Skin Neoplasms; Tissue Extracts

To determine whether activated CD11b(+) CD15(+) granulocytes increase in the blood of patients with uveal melanoma.. Peripheral blood mononuclear cells (PBMCs) were isolated by density gradient centrifugation from the blood of patients with primary choroidal/ciliochoroidal uveal melanomas (six women, four men; age range, 46-91 years) and healthy control donors (14 women, 10 men; age range, 50-81 years). The expression of CD15 and CD68 on CD11b(+) myeloid cells within PBMCs and primary uveal melanomas was evaluated by flow cytometry. CD3zeta chain expression by CD3epsilon(+) T cells in PBMCs and within primary uveal melanomas was measured as an indirect indication of T-cell function.. The percentage of CD11b(+) cells in PBMCs of patients with uveal melanoma increased 1.8-fold in comparison to healthy donors and comprised three subsets: CD68 negative CD15(+) granulocytes, which increased 4.1-fold; CD68(-) CD15(-) cells, which increased threefold; and CD68(+) CD15(low) cells, which were unchanged. A significant (2.7-fold) reduction in CD3zeta chain expression on CD3epsilon(+) T cells, a marker of T-cell dysfunction, was observed in PBMCs of patients with uveal melanoma in comparison with healthy control subjects and correlated significantly with the percentage of CD11b(+) cells in PBMCs. CD3zeta chain expression on T cells within primary tumors was equivalent to CD3zeta expression in PBMCs of the same patient in four of five patients analyzed.. Activated CD11b(+) CD15(+) granulocytes expand in the blood of patients with uveal melanoma and may contribute to immune evasion by ocular tumors by inhibiting T-cell function via decreasing CD3zeta chain expression.

Topics: Aged; Aged, 80 and over; Brachytherapy; CD11b Antigen; CD3 Complex; Centrifugation, Density Gradient; Eye Enucleation; Female; Flow Cytometry; Granulocytes; Humans; Immunoenzyme Techniques; Lewis X Antigen; Lymphocyte Activation; Male; Melanoma; Middle Aged; T-Lymphocytes; Uveal Neoplasms

The classic concept of axillary glands differentiates between eccrine glands, producing abundant clear, nonodorous sweat; and apocrine glands, excreting small amounts of turbid, odorous milky sweat. A third type of sweat glands, the "apoeccrine" glands, were recently identified. To define the different types of sweat glands and their location and number, the authors carried out a prospective histologic study on adult human axillary skin, including various immunohistochemical markers.. Forty-three consecutive Caucasian, subjectively normhidrotic patients, who underwent a surgical procedure in the axilla unrelated to the axillary glands, were included in the study. For verification of normhidrosis, the gravimetric test was carried out by measuring the amount of sweat secretion per minute. Then, a 1 x 1-cm measuring piece of skin and subcutaneous tissue was excised in the apex of the axilla, divided into three samples--altogether, 129 samples--and processed for histologic examination.. In the dermis, the authors found only very few eccrine (average, 0.3 gland/cm in only 12 percent of all patients) and apocrine glands (average, 0.1 gland/cm in only 4.7 percent of patients), and no apoeccrine glands in any patient. In the subcutaneous tissue, the mean number of glands per centimeter squared was 10 for the eccrine glands, nine for the apocrine glands, and six for the apoeccrine glands.. In the authors' Caucasian subjects, all or most of the sweat glands were found in the subcutaneous tissue near the border to the dermis and not in the dermis. For extremely hyperfunctioning sweat glands, the authors recommend less radical surgical methods, with the preservation of skin, based on the knowledge that most glands are localized in the subcutaneous tissue.

Topics: Adult; Aged; Apocrine Glands; Axilla; Biomarkers; Carrier Proteins; Dermis; Eccrine Glands; Female; Glycoproteins; Humans; Lewis X Antigen; Lymph Node Excision; Lymphatic Metastasis; Male; Melanoma; Membrane Transport Proteins; Middle Aged; Organ Specificity; S100 Proteins; Subcutaneous Tissue; Sweat; Sweat Glands; Sweating

The immunobiology of tumor-infiltrating dendritic cells (DCs) can be strongly influenced by the cytokine environment present in the malignant tissue. We have previously identified discrete melanoma lines, inducing E-cadherin expression on monocyte-derived DCs in vitro. We demonstrate here that this effect, independent of cell contact, is not inducible in the presence of tumor lysates and requires the constitutive expression of IFN stimulated gene 15 (ISG15) by malignant cells. High-density oligonucleotide arrays were used to investigate the expression pattern of 7000 genes in RNA from two melanoma cell clones competent for E-cadherin induction and two clones devoid of DC-modulating capacity. A total of 13 genes encoding soluble proteins were expressed at higher magnitude in melanomas able to induce E-cadherin expression on DCs. Combining those data with quantitative protein assays, we could narrow our investigation down to three factors: the chemokine CCL5 and the cytokines ISG15 and type I IFNs. Strikingly, >7 ng/ml of ISG15 could be detected in the corresponding melanoma-conditioned medium and induction of E-cadherin on DCs failed in the presence of antibodies neutralizing ISG15 protein. Most importantly, strong cytoplasmic expression of ISG15 was detected by immunohistochemistry in the original tumor specimen from which the melanoma cell lines under investigation were derived. These data describe a novel property of ISG15 targeting induction of E-cadherin on DCs and possibly influencing their migratory behavior.

Topics: Antibodies; Antigens, CD; B7-2 Antigen; Cadherins; Cell Communication; Culture Media, Conditioned; Cytokines; Dendritic Cells; Gene Expression Profiling; Humans; Lewis X Antigen; Melanoma; Membrane Glycoproteins; Tumor Cells, Cultured; Ubiquitins; Up-Regulation

To gain new insights into the functional interaction between DC and neoplastic cells, we have analyzed the effects of melanoma and colorectal cancer lines on the chemotaxis and the phenotype of monocyte-derived DC in vitro. Both types of tumor cells displayed effective chemoattractive capacity towards immature, but not mature DC. Furthermore, conditioned medium of discrete melanoma lines induced upregulation of CD80, CD86, MHC class I, and MHC class II molecules on immature DC. However, de novo expression of E-cadherin and strong upregulation of CD15 could also be detected in the absence of CD83 expression. Melanoma-conditioned DC exhibited an increased adhesion capacity to a melanoma cell line in vitro and did not migrate in response to SLC chemokine. Tumor-infiltrating CD15(+) cells displaying DC morphology could also be detected by immunohistochemistry in the original tumor specimens from which discrete melanoma cell lines under investigation were derived. Colorectal cancer cell lines, although able to chemoattract immature DC, were apparently unable to modulate their phenotype. Altogether our results suggest that tumor cells can attract immature DC in vitro and, eventually, modulate their phenotype. As a result, DC mobility could be severely impaired.

Topics: Animals; Cadherins; Chemokines; Chemotaxis, Leukocyte; Colorectal Neoplasms; Culture Media, Conditioned; Dendritic Cells; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Immunophenotyping; Lewis X Antigen; Melanoma; Mice; Tumor Cells, Cultured; Up-Regulation

Although rare, renal cell carcinoma (RCC) can metastasize to the bladder. When this occurs, it might complicate diagnosis. Morphologically, RCC can be confused with transitional cell carcinomas (TCCs), especially those exhibiting clear cell features, and also with other bladder tumors, such as paragangliomas and metastatic melanomas. We report seven cases of RCC metastatic to the bladder that occurred in 6 men and 1 woman who were 35 to 69 years old. The most common presenting symptom was the reappearance of hematuria, which developed from 2 to 131 months (mean, 41.3 mo) after the removal of the primary RCC. In all of the patients, the metastatic RCC involved multiple organs; no case had an isolated metastasis to the bladder. The prognosis was poor, and five patients died of disease between 4 and 24 months (mean, 12.8 mo) after diagnosis of the metastasis to the bladder. The remaining two patients were lost to follow-up. All of the tumors were conventional clear or "granular" cell RCCs, with nuclear grades of 2 or 3. In five patients, metastases were confined to the lamina propria, but in two patients, tumors involved the muscularis propria as well. A comparative immunohistochemical study showed that metastatic RCCs were positive for CAM5.2, vimentin, and Leu-M1, and negative for cytokeratin 20, cytokeratin 7, 34betaE12, carcinoembryonic antigen, S-100 protein, HMB45, and chromogranin. Classic and clear cell TCCs were positive for all of the cytokeratins and carcinoembryonic antigen and negative for vimentin. Paragangliomas were positive for chromogranin and showed scattered positivity for the S-100 protein in the sustentacular cells. Metastatic melanomas were positive for S-100 protein and HMB45. The histologic appearance of RCC, particularly the delicate fibrovascular stroma with abundant sinusoidal vessels, is a feature that can be used to recognize the tumor. When there is difficulty diagnosing metastatic RCC, TCC, or other tumors in the bladder, the immunohistochemical findings can assist in the differential diagnosis.

Topics: Adult; Aged; Antigens, Neoplasm; Carcinoembryonic Antigen; Carcinoma, Renal Cell; Carcinoma, Transitional Cell; Chromogranins; Diagnosis, Differential; Female; Humans; Immunohistochemistry; Intermediate Filament Proteins; Keratin-20; Keratin-7; Keratins; Kidney Neoplasms; Lewis X Antigen; Male; Melanoma; Melanoma-Specific Antigens; Middle Aged; Neoplasm Proteins; Paraganglioma; S100 Proteins; Urinary Bladder Neoplasms; Vimentin

The T cell and NK cell adhesion molecule CD2 interacts with different ligands, viz, CD58, CD48, and CD59. Using a fluorescent multimeric construct of rCD2, we previously identified an additional CD2 ligand (CD2L) on the erythroleukemic cell line K562. CD2L bound to a different region of CD2 than known ligands and was N-glycosylation dependent. In this study we show that mAbs specific for the carbohydrate Ag Lewis x (CD15, Gal-beta 1-4 GlcNAc alpha 1-3Fuc) inhibit multimeric rCD2 binding to CD2L. CD2L is restricted in expression to myeloid cells, where it is co-expressed with CD58 on monocytes and is the dominant, if not sole, CD2 ligand on neutrophils. Sugar specificity studies show that CD2L is not CD15. Thus, whereas soluble Lewis x inhibits binding of CD15 mAb to K562 and neutrophils, binding of multimeric rCD2 is unaffected. Furthermore, multimeric rCD2 binding to K562 is inhibited by L-fucose and following treatment of K562 with an alpha 1-6 fucosidase, whereas these treatments do not inhibit the binding of CD15 mAb. Thus, it is likely that CD2L is a carbohydrate structure closely associated with, yet distinct from, CD15, which can be sterically blocked by CD15 mAb. Functional studies revealed that CD2L is probably an important CD2 ligand in the non-MHC-restricted NK cell killing of K562 target cells, since this activity was strongly inhibited by CD15 mAb. Collectively, this study indicates that a CD15 (Lewis x)-associated carbohydrate structure(s), which has previously been shown to be a selectin ligand, also may function as an important CD2 ligand on myeloid cells.

Topics: Antibodies, Monoclonal; Antigen-Antibody Reactions; B-Lymphocytes; Binding, Competitive; Carbohydrate Sequence; CD2 Antigens; Epitopes; Hematopoietic Stem Cells; Humans; Leukemia, Erythroblastic, Acute; Lewis Blood Group Antigens; Lewis X Antigen; Ligands; Melanoma; Molecular Sequence Data; Structure-Activity Relationship; Tumor Cells, Cultured

Twelve established human melanoma lines were screened for surface expression of the carbohydrate antigens Lewisa (Lea), sialyl Lewisa (SLea), dimeric sialyl Lewisa (diSLea), sialyl LewisX (SLex) and dimeric sialyl LewisX (diSLeX). None of the lines expressed SLex, but 11/12 were positive for diSLeX and 7/12 were positive for SLea. Although both diSLeX and SLea have been reported to bind to E-selectin, none of the melanoma lines exhibited E-selectin-dependent adhesion to activated human umbilical vein endothelial cells (HUVECs). Three melanoma lines infected with a retroviral vector carrying the cDNA for the human Lewis fucosyltransferase (FucT-III) subsequently expressed SLeX at their cell surface and exhibited E-selectin-dependent adhesion to activated HUVECs. Treatment of these transduced cells with inhibitors of O-linked or N-linked protein glycosylation significantly inhibited E-selectin-mediated adhesion, though fluorescence-activated cell sorter analysis indicated no decrease in cell surface expression of SLeX, Slea or diSLeX. This suggests that the majority of SLeX/SLea-type glycans endogenously produced by human melanoma cells are not protein-associated and do not mediate E-selectin-dependent adhesion. These results support the hypothesis that E-selectin-dependent adhesion requires presentation of SLeX-type moieties on appropriate glycoproteins.

Topics: Carbohydrate Sequence; Cell Adhesion; DNA, Complementary; E-Selectin; Endothelium, Vascular; Fucosyltransferases; Glycosylation; Humans; In Vitro Techniques; Lewis X Antigen; Ligands; Melanoma; Molecular Sequence Data; Oligosaccharides; Sialyl Lewis X Antigen; Transfection; Tumor Cells, Cultured

The reactivity of monoclonal antibodies from the 5th workshop Selectins/Selectin Ligands panel, directed to the sialylated Lewis(x) and sialylated Lewis(a) determinants, with the human breast carcinoma (BT-20, ZR-75-1 and MDA-MB-468) cell lines, human ovarian carcinoma cell line A2780, fibrosarcoma (HT-1080, B-6FS) and hematopoietic neoplastic (U-937, HL-60, K-562) cell lines were determined with the aid of flow immunocytofluorometry. The examined monoclonal antibodies to sialylated Lewis determinants reacted with examined breast carcinoma, but not with the examined ovarian carcinoma and fibrosarcoma cell lines.

Topics: Antibodies, Monoclonal; Breast Neoplasms; Epitopes; Female; Fibrosarcoma; Flow Cytometry; Fluorescent Antibody Technique; Humans; Leukemia, Promyelocytic, Acute; Lewis Blood Group Antigens; Lewis X Antigen; Melanoma; Neoplasms; Ovarian Neoplasms; Tumor Cells, Cultured

The adhesion molecules E-selectin (ELAM-1) and P-selectin (GMP-140/CD62) recognize the carbohydrate motives sialyl-Le(x), sialyl-diLe(x), or sialyl-Lea, though with different affinity. We found that the melanoma cell line NKI-4 bound to E-selectin, but not to P-selectin. This melanoma cell line did not express sialyl-Le(x), but was positive for sialyl-diLe(x) and sialyl-Le(a). In contrast, 2 other melanoma cell lines, MeWo and SK-MEL-28, expressing either sialyl-diLe(x) or sialyl-Le(a) on the cell surface, bound neither E-selectin nor P-selectin. Transfection of the fucosyltransferases Fuc-TIII, Fuc-TIV, and Fuc-TV mediates cell surface expression of sialyl-Le(x) in many cell lines. We detected transcripts of the fucosyltransferases Fuc-TIII and Fuc-TV in 4 melanoma cell lines despite the absence of cell surface sialyl-Le(x). Our observations indicate that expression of fucosyltransferases (Fuc-TIII and -TV) and generation of cell-surface sialyl-diLe(x) are not sufficient to permit adherence to E-selectin or P-selectin. Furthermore, it seems possible that a yet undefined ligand different from sialyl-Le(x), sialyl-diLe(x), or sialyl-Le(a) enables melanoma cells to adhere to E-selectin.

Topics: Base Sequence; Cell Adhesion; Cell Adhesion Molecules; E-Selectin; Flow Cytometry; Fucosyltransferases; Humans; Lewis X Antigen; Melanoma; Molecular Sequence Data; P-Selectin; Platelet Membrane Glycoproteins; Polymerase Chain Reaction; RNA, Messenger; Tumor Cells, Cultured

This report describes the isolation of a cDNA encoding a novel human Gal beta (1-3/1-4)GlcNac alpha 2,3-sialyl-transferase involved in the biosynthesis of the sialyl Lewis x determinant (NeuAc alpha 2-3 Gal beta 1-4(Fuc alpha 1-3)GlcNAc). A cDNA library of the human melanoma cell line WM266-4 was constructed in an Epstein-Barr virus-based cloning vector. Selection of the B-cell line Namalwa expressing transfected cDNAs in the presence of the cytotoxic lectin Ricinus communis agglutinin 120 gave a cDNA encoding a protein with type II transmembrane topology, as found for mammalian glycosyltransferases. The use of this lectin, which is specific to galactose residues (especially the Gal beta 1-4GlcNAc structure), originates from our prediction that the modification of the Gal beta 1-4GlcNAc structure (a backbone of the sialyl Lewis x structure) by glycosyltransferases may increase the levels of resistance to this lectin. Comparison of this cDNA sequence with those of three other cloned sialyltransferases revealed two conserved regions shared by all four enzymes. Expression of the COOH-terminal catalytic domain of this protein showed alpha 2,3-sialyltransferase activity with substrate specificity different from that of CMP-N-acetylneuraminate:N-acetyllactosaminide alpha-2,3-sialyltransferase (Gal-beta 1-3(4)GlcNAc alpha 2,3-sialyltransferase, EC 2.4.99.6). Furthermore, expression of this cDNA in Namalwa cells increased the level of sialyl Lewis x antigens. The cloning approach based on lectin resistance may be useful for the isolation of cDNAs encoding other mammalian glycosyltransferases.

Topics: Amino Acid Sequence; Animals; Base Sequence; beta-Galactoside alpha-2,3-Sialyltransferase; Blotting, Northern; Carbohydrate Sequence; Cloning, Molecular; Conserved Sequence; DNA Primers; DNA, Complementary; Drug Resistance; Gene Expression; Gene Library; Genetic Vectors; Humans; Lewis X Antigen; Melanoma; Molecular Sequence Data; Polymerase Chain Reaction; Rats; Restriction Mapping; Ricin; Sequence Homology, Amino Acid; Sialyltransferases; Transcription, Genetic; Transfection; Tumor Cells, Cultured

The epidermal growth factor (EGF) receptor in two colon carcinoma lines and in one vulval carcinoma line tested contains carbohydrate determinants that are recognized by monoclonal antibodies to tumor-associated antigens. These antibodies are directed to sialylated Lea and to difucosylated structures of the Y type. Cell lines which react with these antibodies express these antigens on their surface glycolipids and glycoproteins, including the EGF receptor. These unusual carbohydrates are absent in EGF receptors from normal untransformed cells, and from tumor cells which do not express these specific antigens. Although EGF receptor represents only 0.1-2% of total plasma membrane proteins of antigen-positive carcinomas, it accounts for 20-80% of total protein-associated sialylated Lea/Y type of nonsecreted carbohydrates present in these cells. The results of cell-binding, immunoprecipitation, and Western blot analyses of the antigen-positive carcinomas indicate that sialylated Lea/Y type of antigenicity is intrinsic to the EGF receptors of these cells, and that the antigen is present in receptors from both over-expressing and normal-expressing carcinomas.

Topics: Animals; Antibodies, Monoclonal; Antigens, Neoplasm; Carbohydrates; Carcinoma; Cell Line; Colonic Neoplasms; Electrophoresis, Polyacrylamide Gel; Epitopes; ErbB Receptors; Female; Glycolipids; Humans; Lewis Blood Group Antigens; Lewis X Antigen; Melanoma; Membrane Proteins; Mice; Uterine Cervical Neoplasms; Vulvar Neoplasms