Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: KEGG:D00046 (lactose)
 16,692 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

One hundred and fifty patients with advanced cancer participated in a controlled double-blind study to evaluate the effects of high-dose vitamin C on symptoms and survival. Patients were divided randomly into a group that received vitamin C (10 g per day) and one that received a comparably flavored lactose placebo. Sixty evaluable patients received vitamin C and 63 received a placebo. Both groups were similar in age, sex, site of primary tumor, performance score, tumor grade and previous chemotherapy. The two groups showed no appreciable difference in changes in symptoms, performance status, appetite or weight. The median survival for all patients was about seven weeks, and the survival curves essentially overlapped. In this selected group of patients, we were unable to show a therapeutic benefit of high-dose vitamin C treatment.
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PMID:Failure of high-dose vitamin C (ascorbic acid) therapy to benefit patients with advanced cancer. A controlled trial. 38 41

Two toxic proteins were purified from the seeds of Abrus precatorius by DEAE-A 50 and Sepharose 4B chromatography. One of them does not bind on the Sepharose 4B column (Abrin-b) and the other (Abrin-a) is eluted with 0.2 M galactose. The amino acid compositions and tryptic maps of these two proteins were similar, but not identical. The molecular weights estimated by SDS-gel electrophoresis were 67,000 for abrin-b as compared with 65,000 for abrin-a. In the presence of mercaptoethanol, both abrin-a and abrin-b gave rise to two bands. The lethal doses of abrin-a and abrin-b for mice recorded within 48 h were 10 and 25 microgram per kg of body weight respectively. Abrin-a at 0.8 microgram per ml concentration level agglutinated human 0-type erythrocytes, whereas abrin-b showed no such activity. Abrin-a at 5 microgram per ml concentration level agglutinated both the Sarcoma 180 cells and Ehrlich ascites tumor cells, but it required 150 microgram per ml for abrin-b. Both these two proteins at a sublethal dose could inhibit the growth of Ehrlich ascites tumor cells which were injected simultaneously with these proteins. 131I-abrin-a and 131I-abrin-b were able to bind Sarcoma 180 cells, and the binding of abrin-a could be inhibited by lactose, raffinose, galactose and rhamnose, but none of 15 sugars tested inhibited the binding of abrin-b.
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PMID:Isolation of antitumor proteins abrin-A and abrin-B from Abrus precatorius. 74 90

Ductal infiltration carcinomas (d.i.c.) of the breast are potentially highly metastatic tumours, associated with drastic alterations of the architecture and molecular composition of the extracellular matrix at the tumour-host interface. 8701-BC, a recently characterized cell line, isolated from primary d.i.c., was used to study different aspects of tumor cell-substratum interactions. Since type V collagen deposition is augmented in d.i.c. we have examined the ability of 8701-BC cells to interact with this collagen species. We have found that cell binding to type V collagen was mediated by protein homologous to the 67 kDa laminin receptor (67-R). This conclusion is substantiated by the following observations: (a) a major band having an apparent molecular mass of 67 kDa and immunoreactive to the anti-67 R antibody was detectable by SDS-PAGE of the membrane proteins; (b) the antibody inhibited cellular adhesion to type V collagen in a dose-dependent way; (c) membrane proteins purified by affinity chromatography on type V collagen were immunoreactive to anti-67 R antibody, but not to anti-VLA1, VLA2 and VLA3 integrin antibodies. This receptor appears to have prominent carbohydrate-binding properties, since lactose competes with cell adhesion to type V collagen.
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PMID:Adhesion of 8701-BC breast cancer cells to type V collagen and 67 kDa receptor. 132 62

The carbohydrate moieties present on laminin play a crucial role in the multiple biological activities of this basement membrane glycoprotein. We report the identification of a human laminin binding protein with an apparent molecular mass of 14 kDa on sodium dodecyl sulfate-polyacrylamide gels that was found, after purification and amino acid microsequencing, to be identical to the previously described 14-kDa galactoside binding soluble L-14 lectin. We have designated this human laminin binding protein as HLBP14. HLBP14 was purified from human melanoma cells in culture by laminin affinity chromatography and gel electroelution. We demonstrate that HLBP14 binds specifically to the poly-N-acetyllactosamine residues of murine laminin and does not bind to other glycoproteins that do not contain such structures, such as fibronectin. HLBP14 was eluted from a murine laminin column by lactose, N-acetyllactosamine, and galactose but not by other control saccharides, including glucose, fucose, mannose, and melibiose. It did not bind to laminin treated with endo-beta-galactosidase. Lactose also eluted HLBP14 off a human laminin affinity column, implying that human laminin also contains poly-N-acetyllactosamine residues. On immunoblots, polyclonal antibodies raised against HLBP14 recognized HLBP14 as well as 31- and 67-kDa molecules that are also laminin binding proteins, indicating that these proteins share common epitopes. L-14, a dimeric lactose binding lectin, is expressed in a wide variety of tissues. Although the expression of this molecule has been linked to a variety of biological events, the elucidation of its specific functions has been elusive. The observation that HLBP14, a human cancer cell laminin binding protein, is identical to L-14 strongly suggests that the functions attributed to this lectin could be mediated, at least in part, through its ability to interact with the poly-N-acetyllactosamine residues of laminin. HLBP14 could potentially play a role during tumor invasion and metastasis by modulating the interactions between cancer cells and laminin.
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PMID:Identification of a 14-kDa laminin binding protein (HLBP14) in human melanoma cells that is identical to the 14-kDa galactoside binding lectin. 138 13

Initial adhesion of B16 melanoma variants to non-activated endothelial cells is mediated through specific interaction between GM3 (NeuAc alpha 2----3Gal beta 1----4Glc beta 1----Cer) expressed on melanoma cells and lactosylceramide (LacCer, Gal beta 1----4Glc beta 1----Cer) expressed on endothelial cells. This adhesion is predominant over integrin- or lectin-mediated adhesion in a dynamic flow experimental system employing a parallel plate laminar flow chamber (Lawrence, M. B., Smith, C. W., Eskin, S. G., and McIntire, L. V. (1990) Blood 75, 227-237). In this system, a tumor cell suspension flows over a glass plate coated with glycosphingolipid, lectin, or fibronectin, and adhesion is recorded on videotape. These conditions were designed to mimic the microvascular environment in which tumor metastatic deposition takes place. In contrast, lectin- and fibronectin-based mechanisms are predominant in previously used static adhesion systems. Under static conditions, the relative degree of adhesion of the four B16 variants to endothelial cells or to LacCer-coated plates was the same as their relative degree of GM3 expression (i.e. BL6 approximately F10 greater than F1 greater than WA4), and adhesion was inhibited in the presence of methyl-beta-lactoside, or liposomes containing LacCer or GM3. Adhesion was also inhibited by pretreatment of B16 cells with anti-GM3 antibody DH2 or sialidase and by pretreatment of endothelial cells with anti-LacCer antibody T5A7. Under dynamic flow conditions, WA4 cells did not adhere to mouse endothelial cells at high shear stress (greater than 2.5 dynes/cm2) but did adhere at lower shear stress. In contrast, BL6 and F10 cells adhered strongly at both low and high shear stress. BL6 cell adhesion to endothelial cells at both low and high shear stress was inhibited in the presence of antibody DH2, ethyl-beta-lactoside, or lactose, as well as by pretreatment of BL6 cells with sialidase. Thus, some clear differences, as well as similarities, in cell adhesion under static versus dynamic conditions are demonstrated. These findings suggest that melanoma cell adhesion to endothelial cells, based on GM3/LacCer interaction, initiates metastatic deposition, which may trigger a series of "cascade" reactions leading to activation of endothelial cells and expression of Ig family or selectin receptors, thereby promoting adhesion and migration of tumor cells.
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PMID:Cell adhesion in a dynamic flow system as compared to static system. Glycosphingolipid-glycosphingolipid interaction in the dynamic system predominates over lectin- or integrin-based mechanisms in adhesion of B16 melanoma cells to non-activated endothelial cells. 151 64

The effects of cell differentiation on cell adhesion to laminin were studied using the human colon tumor cell line, HT29. HT29 cells were induced to differentiate either by glucose deprivation (HT29glc- vs HT29glc+) or by 2 mM butyrate (HT29glc-+B+). Adhesion was assayed after incubating cell suspensions in microtiter wells previously coated with laminin or other substrates. HT29glc+ cells adhered preferentially to laminin over BSA, fibronectin, and ovalbumin. The adhesion to laminin was greater than 50% of maximum within 15 min. HT29glc- cell adhesion to laminin was consistently lower than that for HT29glc+ or HT29glc+B+ cells. alpha-Lactalbumin (ALA), a modifier of galactosyltransferase (GT) substrate specificity, caused a significant reduction (greater than 50%) in HT29glc+ cell adhesion to laminin when ALA was added to the adhesion incubation mixture. Addition of glucose+ALA to the suspension restored adhesion to laminin. Ovalbumin, a GT substrate, increased adhesion of HT29glc+ and HT29glc- cells to laminin, but lactose, a GT product, did not. The data show that undifferentiated HT29 cells adhere preferentially to laminin over fibronectin and collagen IV and that differentiation of HT29 cells reduces adhesion to laminin. In addition, the data imply that cell adhesion to laminin may be mediated by factors that also modify galactosyltransferase activity.
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PMID:Colonic cancer cell (HT29) adhesion to laminin is altered by differentiation: adhesion may involve galactosyltransferase. 163 32

Mucin-specific lectin from Sambucus sieboldiana (SSA-M) reacts in Western blotting and ELISA with mucins from porcine stomach, bovine and ovine submaxillary glands, the human milk fat globule membrane, in vitro human ovarian, breast and colonic tumor cell lines, and mucins produced in vivo in the ascites of patients with endometrial and ovarian tumors, but not with fetal bovine fetuin or human transferrin. Sialidase treatment of these mucins led to an increase in the binding of SSA-M, suggesting that sialic acid is not part of the binding site for this lectin. Furthermore, sialic acid did not inhibit lectin binding. Treatment of asialomucin with O-glycanase decreased the binding of SSA-M, confirming the reactivity of the lectin with an O-linked carbohydrate. Treatment of mucins with trifluoromethanesulfonic acid, which removes all but core carbohydrate, led to an increase in the binding of SSA-M, suggesting that the lectin reacts with O-linked core glycans. Indeed, the increased reactivity after sialidase treatment of ovine submaxillary mucin suggests the lectin reacts with peptide-linked N-acetylgalactosamine (GalNAc), since more than 98% of the glycan chains attached to this mucin are sialylated GalNAc. The binding of SSA-M to sialidase-treated porcine mucin was inhibited strongly by GalNAc and disaccharides containing galactose (lactose, melibiose, and N-acetyllactosamine) but not by free galactose (Gal), suggesting that the glycan for optimum binding is Gal beta(1-3)GalNAc. This pattern of inhibition was different to other core glycan-reactive lectins tested, indicating that SSA-M is distinct, and should be of use in the isolation and characterisation of mucins and O-linked glycans.
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PMID:Reactivity of mucin-specific lectin from Sambucus sieboldiana with simple sugars, normal mucins and tumor-associated mucins. Comparison with other lectins. 166 64

The monoclonal antibody L6 recognizes a determinant that is expressed on lung, breast, colon, and ovarian carcinomas and is present only at trace levels in normal tissues. L6 was covalently linked to intact ricin by a thioether bond to produce an immunotoxin (IT). Gel analysis revealed that this IT was heterogeneous, but mostly one monoclonal antibody molecule linked to one ricin molecule. The L6-ricin IT selectively bound and was selectively toxic to L6-positive H2981-T3 adenocarcinoma cells in protein synthesis inhibition assays in which lactose was added to block the native ricin binding site. Clonogenic studies showed that 1 microgram/ml L6-ricin could inhibit about 99.99% of H2981-T3 growth in a limiting dilution assay, even in the presence of a 20-fold excess of human bone marrow cells. Treatment of bone marrow cells with the same dose of L6-ricin resulted in the growth of ample numbers of bone marrow progenitor cells (colony-forming units-mixed, colony-forming units granulocyte/macrophage, and blast-forming units erythroid) after 14 days. We also evaluated the antitumor effect of L6-ricin administered intratumorally with lactose against established H2981-T3 tumors in a nude mouse model. Thirty % of the tumor-bearing animals responded completely to single-dose treatment, while 60% gave partial responses. The in vivo effects were not absolutely specific, since irrelevant anti-CD5 IT also induced tumor regression in this model (10% responded completely, while 30% gave partial responses). However, irrelevant IT gave higher systemic toxicity (50% mortality) than L6-ricin (23% mortality). The nonspecific activity of IT was possibly due to Fc binding, which was demonstrated in vitro, or due to ricin B-chain binding. Ricin alone was too toxic for sustained tumor protection. Unconjugated L6 had no antitumor effect. The data suggest that L6-ricin may be useful for in vitro purging of autologous bone marrow from patients with solid tumors and marrow involvement and for in vivo regional therapy of L6-positive carcinomas.
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PMID:Antitumor activity of L6-ricin immunotoxin against the H2981-T3 lung adenocarcinoma cell line in vitro and in vivo. 169 58

The paper continues in the previous experiment indicating a possible control of glycosylation and differentiation processes in the in vitro cultured tumor cells using suitable types of saccharides in the culture medium. In this experiment the effect of lactose, L-fucose, D-glucose, and D-galactose was studied. To determine glycosylative changes the panel of six lectins with various sugar specificity was used. The obtained results indicate that a specific sugar may significantly affect not only the growth of cells but also glycosylation processes, including cell differentiation.
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PMID:Further experience with the effect of some sugars on the growth and glycosylation of tumor line MCF-7. 184 Mar 39

Lactose-binding lectins having Mr values of approximately 14,000 (L-14.5) and approximately 35,000 Da have been found in a variety of vertebrate tissues, including normal intestine and colon, and in several types of tumors such as colon carcinomas. To determine the clinical relevance of such lectins in human colon cancer, specimens from 46 patients with colorectal carcinoma of identified Dukes' stages were selected and analyzed for the presence and amount of lactose-binding lectins by immunoblotting using a polyclonal, rabbit anti-lectin antibody followed by binding of 125I-labeled anti-rabbit IgG. The amount of a lectin having an Mr value of approximately 31,000 Da (L-31) varied among the specimens. The levels of L-31 lectin in colorectal cancer specimens from primary tumors of patients with distant metastases (Dukes' stage D) were significantly higher than were those from patients without detectable metastases (Dukes' stages B1 and B2). In contrast, among the various specimens the variation in the level of the L-14.5 lectin was smaller, and there was no correlation between the amount of this lectin and cancer stage. Immunohistochemical staining of thin sections of colorectal tumor specimens using antibodies specific for either L-31 or L-14.5 lectin revealed that the two were located at different places, the L-31 lectin primarily within the cytoplasm of carcinoma cells, and the L-14.5 lectin associated with secreted material. These results indicated that the relative amount of the L-31 lectin increases as the colorectal cancer progresses to a more malignant stage.
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PMID:Lactose-binding lectin expression in human colorectal carcinomas. Relation to tumor progression. 193 52


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