Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0006142 (breast cancer)
 160,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to develop reagents that can detect the exposed core carbohydrate antigens of mucins, we have prepared monoclonal antibodies against partially deglycosylated LS174T human colon cancer mucin. The three monoclonal antibodies, 10F4, 15D3a, and 91S8, stained cancers of the colon, pancreas, stomach, breast, prostate, and lung to a greater extent than corresponding normal tissues. There was no staining of normal pancreas or breast, suggesting that these antibodies may be particularly useful for detecting cancers in these two organs. In homogenates of cultured cancer cells, antigen was detectable in three colon cancer cell lines, but not in a variety of other epithelial cancers. The epitope specificity of all three monoclonal antibodies appears to be for Tn antigen, i.e. GalNAc-alpha-Ser/Thr, based on their recognition of alpha-linked GalNAc, but not T antigen, sialyl Tn, or a range of other structures. However, the three anti-Tn antibodies differed in tissue staining specificity and in relative binding to different mucins. These monoclonal antibodies, prepared against deglycosylated colon cancer mucin, appear to be useful reagents for the immunohistochemical detection of epithelial cancers, especially pancreatic cancer and breast cancer.
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PMID:Monoclonal antibodies against partially deglycosylated colon cancer mucin that recognize Tn antigen. 128 Oct 60

Second generation antibodies to mammary mucins were produced by immunizing mice with a peptide with a sequence deduced from that of the MUC1 complementary DNA sequence (PAHGVTSAPDTRPAPGSTAP). Four monoclonal antibodies (BCP7-10) were produced which gave different reactions. BCP8 was similar in tissue reactivity (by immunoperoxidase staining) to anti-breast cancer or anti-human milk fat globule membranes (HMFG) antibodies and reacted strongly with most breast cancers and a proportion of other adenocarcinomas, whether formalin fixed or fresh, and reacted less strongly with some normal tissues. The three other antibodies (BCP7, BCP9, BCP10) reacted only with fresh tissues or a single cell line (LS174T of colon cancer origin) and gave variable weak reactions. Like many anti-mucin antibodies BCP8 reacted with HMFG, but more strongly with deglycosylated HMFG; analysis with peptides by enzyme-linked immunosorbent assay indicated reactivity with an epitope contained in the amino acid motif PDTR and using the pepscan method, the minimum epitope was DTR. MAbs BCP7, BCP9, and BCP10 did not react with HMFG; substantial reactions were obtained with deglycosylated HMFG for BCP7 and weaker reactions with BCP9 and BCP10. The finding that BCP7 reacted with breast cancer tissues and deglycosylated HMFG suggested that the epitope recognized by BCP7 was masked in native form and exposed in cancer, indicating that BCP7 could be a useful agent for analyzing differences between normal and cancer mucins. The amino acid epitopes for these antibodies were VTSA (BCP7), GSTAP (BCP9), and RPAP (BCP10). For BCP8, amino acid substitution analysis of SAPDTR indicated that substitutions were poorly tolerated (except Q for T and L/Y for R), contrasting with the substitution analysis of anti-mucin antibody reactions where virtually any amino acid can be substituted for T, indicating that in the native state T (threonine) may be O-glycosylated. The use of synthetic peptides to produce antibodies similar to those produced using crude mucins or tumor extracts represents a major advance in the production of antitumor reagents.
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PMID:Second generation anti-MUC1 peptide monoclonal antibodies. 137 8

The hypothesis that tumors arising in a particular organ site impose a characteristic plasma free amino acid (PFAA) pattern was tested by analyzing PFAA in fasting venous blood of preoperative patients with breast cancer, gastrointestinal tract cancer, and head and neck cancer. Healthy volunteers served as control subjects. Levels of 28 PFAA were determined in blood samples using an amino acid analyzer, and the data were compared using discriminant analysis and chi-square testing. Compared with control subjects, the concentrations of seven amino acids (glutamine, threonine, histidine, cysteine, alanine, arginine, and ornithine) in patients with tumors correlated closely with the known diagnoses. By means of discriminant analysis, these seven amino acids had the highest correlation with the specific diagnoses, indicating that PFAA profiles correlate diagnostically with the organ-site origin of three different kinds of malignant tumors.
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PMID:Amino acid profiles correlate diagnostically with organ site in three kinds of malignant tumors. 156 82

Availability of accurate prognostic factors is vital in making decisions on cancer therapy. We have measured the cytosolic contents of phosphoethanolamine and ethanolamine in tumor tissues of 53 breast cancer patients in an attempt to explore the possibility that these amines could be used as prognostic indicators. The levels of phosphoethanolamine and ethanolamine were determined by high-performance liquid chromatography. The ratios of the molar quantity of these amines or amino acids to that of alanine plus tyrosine, which eluted as a single peak, were used to analyze and compare the results among different tumor samples. The results indicated that the values for phosphoethanolamine or ethanolamine varied significantly more than the values for amino acids, such as glycine plus threonine or glutamine plus serine (these amino acids were eluted as single peaks, respectively). The values for phosphoethanolamine, ethanolamine, and phosphoethanolamine plus ethanolamine were analyzed in relation to several commonly used prognostic factors of breast disease. The results indicated that groups having higher mitotic indices had significantly higher values for phosphoethanolamine or phosphoethanolamine plus ethanolamine than the group having lower mitotic indices. As the stage of the disease increased, the values for phosphoethanolamine plus ethanolamine also seemed to become higher. No correlation, however, was observed between steroid hormone receptor positive and negative groups or between positive and negative groups with regard to involved axillary lymph nodes. The content of phosphoethanolamine or phosphoethanolamine plus ethanolamine in cytosol therefore seems to be correlated with some prognostic indicators.
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PMID:Analysis of cytosolic phosphoethanolamine and ethanolamine and their correlation with prognostic factors in breast cancer. 190 50

The binding characteristics of several somatostatin (SS-14) analogs developed in our laboratory were examined in various human and animal tumors and normal tissues. In rat cerebral cortex and human breast cancer membranes the interaction of SS-14 with its binding sites was rapid, specific, saturable, linear with protein concentrations, and dependent on time and temperature. Analysis of kinetic and equilibrium experimental data showed that the interaction of [125I-Tyr11]SS-14 with the binding sites in all normal and tumoral tissue specimens was consistent with the presence of a single class of noncooperative binding sites. Superactive octapeptide analogs of somatostatin-containing hexapeptide sequences Cys-Phe-D-Trp-Lys-Thr-Cys or Cys-Tyr-D-Trp-Lys-Val-Cys showed significant binding affinities to SS-14 receptors. Among these analogs, D-Trp-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-NH2 (RC-98-I) showed the highest binding affinity to normal human pancreatic tissue and human pancreatic adenocarcinoma. In contrast, Sandostatin (SMS 201-995) bound only to normal pancreas, not to human pancreatic cancers. Analog RC-98-I also showed a high binding to human and rat prostate cancers. In human epithelial ovarian cancers and an arrhenoblastoma, analogs D-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Trp-NH2 (RC-95-I), D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Thr-NH2 (RC-121) and D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2 (RC-160) appeared to be the most potent in displacing labeled SS-14. Analogs Ac-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-NH2 (RC-101-I) as well as RC-121, RC-160, and RC-95-I, but not SMS-201-995, showed high binding affinity in human breast cancers. In specimens of human meningioma the highest binding was found with analogs RC-121, RC-95-I, and RC-101-I. Since marked variations in binding affinities were noted for several analogs in the tissues of origin and the tumors, this suggest that differences may exist between somatostatin receptors not only in normal vs. cancerous tissues, but also among various tumors. Our findings also imply that some analogs could be therapeutically superior to others in the treatment of certain tumors.
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PMID:Evaluation of receptors for somatostatin in various tumors using different analogs. 196 67

The neu proto-oncogene product has been found to exist in two interconvertible forms in G8/DHFR mouse fibroblasts. The 185-kilodalton form (p185) present in growing cells is replaced by a 175-kilodalton form (p175) under conditions of serum starvation. This low molecular weight form accounts almost exclusively for the phosphotyrosine content of the receptor and is associated with increased tyrosine kinase activity. Addition of serum, platelet-derived growth factor or tumor promoter induces conversion of p175 to p185 within minutes, and this increase in molecular weight is associated with phosphorylation of serine and threonine; removal of serum growth factors is followed by replacement of p185 with p175 over several hours. Unlike G8/DHFR cells, the human breast cancer cell line SK-Br-3 expresses a high molecular weight neu/HER2 receptor with unchanged phosphotyrosine content in both serum-starved and serum-stimulated cultures. These findings indicate that activation of the neu proto-oncogene product in G8/DHFR cells may be regulated in part by protein kinase C-mediated receptor transmodulation rather than by ligand availability alone.
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PMID:Modulation of a Mr 175,000 c-neu receptor isoform in G8/DHFR cells by serum starvation. 197 80

Two monoclonal antibodies, TKH1 and TKH2, directed toward the sialosyl-Tn structure (NeuAc alpha 2----6GalNAc alpha 1----O-Ser or Thr), which display a remarkable immunohistological tumor specificity, were generated by immunization with ovine submaxillary mucin. The reactivity of these antibodies was monitored by solid phase enzyme-linked immunosorbent assay with different native and glycosidase-treated mucins and glycoproteins. Binding of the antibody to ovine submaxillary mucin glycoprotein was strongly inhibited by the O-linked disaccharide NeuAc alpha 2----6GalNAc alpha 1----O-serine, less strongly by NeuAc alpha 2----6GalNAc beta 1----O-propyl, and weakly by the monosaccharide GalNac. The reactivity was compared with previously established anti-Tn antibodies B72.3, NCC-Lu-35, and NCC-Lu-81. The antibody B72.3 was prepared previously after immunization with metastatic breast adenocarcinoma and its epitope was claimed to be GalNAc alpha 1----O-Ser (or - Thr) by Springer and associates [Springer, G.F., et al. In: T. Dao, et al. (eds.), Tumor Markers and Their Significance in the Management of Breast Cancer, pp. 47-70. New York: A.R. Liss, 1986]. The antibody was found to show very similar reactivity as that of TKH1/TKH2, and its reactivity to ovine submaxillary mucin was inhibited specifically by NeuAc alpha 2----6GalNAc alpha 1----O-serine, indicating that the antibody is clearly directed to sialosyl-Tn antigen. Immunohistological study of the distribution of this antigen in various normal human tissues and carcinomas by TKH1/TKH2 antibodies, as well as B72.3 and monoclonal antibodies NCC-Lu-35/81, which are directed to GalNAc alpha 1----O-Ser or Thr (Tn), was performed. The sialosyl-Tn antigen was not found in normal tissue except for a weak expression in Leydig cells of the testis, goblet cells of the colon, and parietal cells of the stomach. In contrast, the sialosyl-Tn antigen was strongly expressed in a large number of adenocarcinomas. As expected from the specificity studies, B72.3 shows the same reactivity as TKH1 and TKH2. Thus, both sialosyl-Tn (NeuAc alpha 2----6GalNAc alpha 1----O-Ser/Thr) and Tn (GalNAc alpha 1----O-Ser/Thr) are good tumor markers, and combined use of antibodies directed to these structures might be useful in the screening and classification of cancer.
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PMID:Preparation and characterization of monoclonal antibodies directed to the tumor-associated O-linked sialosyl-2----6 alpha-N-acetylgalactosaminyl (sialosyl-Tn) epitope. 245 Jun 49

Several forms of protein kinase C with molecular masses of 74-, 77-, and 80-kDa were detected in subcellular fractions of human breast cancer MDA-MB-231 cells which express the alpha-type protein kinase C. Several lines of evidence indicated that the 74-kDa is the precursor of the 77- and 80-kDa protein kinase C forms. (i) Pulse-labeling experiments revealed that protein kinase C is synthesized on membranes as a 74-kDa protein that can be chased into the 77- and the 80-kDa protein kinase C forms. (ii) The primary translation product of protein kinase C displayed an apparent molecular size of 74-kDa as determined by in vitro translation of poly(A)+ RNA from MDA-MB-231 cells. (iii) Incubation with serine/threonine-specific protein phosphatases (potato acid phosphatase and phosphatase 1 or 2A) resulted in the complete dephosphorylation of the 77-kDa to the 74-kDa protein kinase C form. Protein kinase C appears to be synthesized in membranes as an unphosphorylated and presumably inactive 74-kDa form that is converted into the active 77- and 80-kDa protein kinase C by post-translational modification involving at least two phosphorylation steps. The first phosphorylation is probably achieved by a specific, yet unidentified, "protein kinase C kinase" since the 74-kDa protein kinase C species did not undergo autophosphorylation and was neither a substrate for the purified protein kinase C, S6 kinase, phosphorylase kinase, casein kinase II, nor for the catalytic subunit of cAMP-dependent protein kinase. Except for phosphorylase kinase and the catalytic subunit of the cAMP-dependent protein kinase, phosphorylation of the 77-kDa protein kinase C form with purified protein kinase C (autophosphorylation), S6 kinase or casein kinase II shifted the molecular mass of the 77-kDa protein kinase C to 80-kDa. Prolonged exposure of MDA-MB-231 cells to phorbol 12-myristate 13-acetate not only leads to a complete down-regulation of protein kinase C activity but also to an accumulation of 74-kDa protein kinase C due to a retarded conversion of the 74-kDa into the 77- and 80-kDa protein kinase C forms in these cells. Our data indicate that tumor promoters additionally interfere with the posttranslational processing that converts the 74-kDa protein kinase C precursor into the 77- and 80-kDa forms of the enzyme.
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PMID:Biosynthesis and posttranslational modifications of protein kinase C in human breast cancer cells. 247 38

1. In previous studies we have isolated and characterized mucin-type glycopeptides from mouse and human melanoma cells. 2. These glycopeptides have clusters of oligosaccharides of the type (NeuNAc)0-2----[Gal----GalNAc] linked to serine and or threonine suggesting an apparent similarity to glycophorin. 3. We now report the interaction of polyclonal anti-glycophorin antibodies with various cultured cells. Antisera to highly purified glycophorin A were raised in rabbits. 4. Human melanoma cells (HM7), human breast cells (HBL-100) and two lines of human breast cancer cells (MCF-7 and MDA-MB-231) showed medium to very strong cell surface fluorescence pattern after staining with rabbit anti-glycophorin F(ab')2 and FITC-conjugated goat anti-rabbit F(ab')2. 5. Immunodiffusion, immunoelectrophoresis and affinity chromatography on anti-glycophorin IgG-Sepharose 4B of detergent extracts of metabolically labeled cultured cells gave further evidence for the presence of glycophorin-like components in these cells. 6. Glycoproteins of MCF-7 cells interacting with anti-glycophorin antibodies were affinity purified and partially characterized.
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PMID:Detection of glycophorin A-like glycoproteins on the surface of cultured human cells. 250 71

Metabolism of the epidermal growth factor (EGF) receptor was studied in the MDA-MB-231 human breast cancer cell line. As in normal fibroblasts the EGF receptor from MDA-MB-231 cells was synthesized from a Mr = 160,000 precursor and tunicamycin treatment of cells resulted in accumulation of a Mr = 130,000 polypeptide. Unlike normal fibroblasts in which a Mr = 170,000 mature form of the EGF receptor was found, MDA-MB-231 cells contained a Mr = 172,000 mature form. Addition of EGF to MDA-MB-231 cells led to rapid internalization of EGF receptors, however, internalization did not affect receptor half-life and receptors did not recycle to the cell surface. EGF receptors could be visualized by immunofluorescence and remained sequestered in intracellular membranous structures following internalization. EGF was degraded slowly by MDA-MB-231 cells relative to degradation of EGF by normal cells. A high endogenous level of in vivo phosphorylation of threonine 654 of the EGF receptor was found in MDA-MB-231 cells and treatment of cells with 12-O-tetradecanoyl-phorbol-13-acetate (TPA) further stimulated phosphorylation of this residue. EGF induced receptor internalization resulted in dephosphorylation of threonine 654. The significance of these unusual properties of EGF receptor metabolism in MDA-MB-231 cells is discussed.
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PMID:Epidermal growth factor induces internalization but not degradation of the epidermal growth factor receptor in a human breast cancer cell line. 305 91


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