Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:APRD00631 (Gel)
 14,881 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We developed a high-titer polyclonal antiserum to a glycoprotein tumor-associated antigen (TAA) by immunization of a baboon with the purified glycoprotein antigen. The baboon serum was fractionated into IgG and IgM components by DEAE Affi-Gel blue chromatography. The ability of the baboon IgM anti-TAA antibody to effect tumor cell lysis in the presence of complement was tested using a chromium-release assay. The baboon antibody was able to lyse melanoma target cells (20.8%-71.4% cytolysis), breast carcinoma cells (36.5%-38.9% cytolysis), and a neuroblastoma cell line (35.5% cytolysis) in the presence of complement but did not effect significant lysis of autologous lymphoblastoid cell lines (4.9% cytolysis) or peripheral blood lymphocytes from healthy volunteers (12.6% cytolysis). Cytolysis of melanoma target cells was completely inhibited by preabsorption of the IgM anti-TAA antibody with UCLA-SO-M14 (M14) cells and partially inhibited by preabsorption with several other melanoma cell lines. There was no significant inhibition of tumor cell lysis after preabsorption of the antibody with lymphoblastoid cell lines. Complement-dependent lysis of M14 targets could be blocked by addition of the purified antigen to the antibody prior to incubation with the tumor cells. Our results suggest that the glycoprotein TAA resides on the tumor cell surface and that the baboon IgM anti-TAA antibody recognizes the antigen on the cell surface and is able to fix complement and effect the lysis of the tumor cells.
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PMID:Complement-dependent lysis of tumor cells by a baboon IgM antibody to a tumor-associated antigen. 156 14

In a search for monocyte-specific nuclear factors, we analyzed in human cells the promoter of the chicken myelomonocytic growth factor, a gene that, in the chicken, is expressed in myeloid and myelomonocytic cells. Reporter gene constructs were active in monocytic Mono Mac 6 cells and in monoblastic THP-1 cells but not in the hematopoietic stem cell line K562. When a region with homology to the sequence recognized by CAAT enhancer-binding proteins (C/EBP) was inactivated by site-directed mutagenesis, the reporter activity was reduced by a factor of 10. Multimers of this region, termed F, in front of a heterologous promoter were active in Mono Mac 6 and THP-1 cells but not in K562 cells, WIL2 B cells, BT20 mammary carcinoma cells, MelJuso melanoma cells, or SK-Hep-1 hepatoma cells. Gel shift analysis with the F oligonucleotide identified DNA-binding activity in monocytic Mono Mac 6, monoblastic THP-1, and myelomonocytic HL60 cells. No binding was detected in myelomonocytic RC2A cells, in myeloid KG-1 cells, or in the hematopoietic stem cell line K562. Furthermore, a panel of solid tumor cell lines, representing various tissues, were also negative. Stimulation by PMA could not induce this binding factor in any of the negative cell lines. Analysis of primary cells (granulocytes, T cells, monocytes, and alveolar macrophages) revealed binding activity only in monocytes and macrophages. This DNA-binding factor, termed NF-M, was found to consist of two molecules, of 50 and 72 kDa, as determined by affinity cross-linking. Binding of NF-M was competed by the region F oligonucleotide and by the C/EBP motif from the albumin enhancer but not by an AP-2 motif. These data suggest that NF-M is a member of the C/EBP family of nuclear factors. The monocyte-restricted activity of NF-M suggests that this nuclear factor may be involved in regulation of monocyte-specific genes.
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PMID:Constitutive monocyte-restricted activity of NF-M, a nuclear factor that binds to a C/EBP motif. 160 56

The transcriptional mechanisms which contribute to the regulation of nerve growth factor (NGF) production are still largely unknown. We previously expressed the NGF promoter region in transgenic mice to localize cis regulatory elements to within 5 kb of the promoter. To further map these elements, and to begin to study the corresponding transacting factors, we here assayed the effects of 5' deletions and point mutations and examined the binding of nuclear factors to the NGF promoter region using L929 cell fibroblasts. Sequential deletions delineated regions upstream from the promoter which stimulated and inhibited transcription. DNAse-1 footprinting experiments identified four upstream segments, designated F2, F4, F6 and F8, which bound L929 cell nuclear proteins. F2 and F4 mapped to stimulatory and F6 and F8 to inhibitory regions. Competition experiments using a heptanucleotide present in both F2 and F4 segments suggested that they may be bound by related factors. Gel shift assays showed that the F8 binding proteins are less abundant in L929 cells than in NIH 3T3 fibroblasts and B16 melanoma cells. In addition to the upstream segments, a downstream AP-1 consensus sequence bound L929 nuclear proteins. Mutation of the AP-1 consensus sequence eliminated binding of nuclear proteins and reduced transcriptional activity. Our results indicate that transcriptional activator as well as suppressor regions surround the NGF gene promoter. The regulation of NGF production is likely to involve cis elements within these regions and transacting factors that bind to them.
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PMID:Structural and functional identification of regulatory regions and cis elements surrounding the nerve growth factor gene promoter. 166 23

Normal human foreskin fibroblasts were used to examine transcriptional induction by IL-1 and TNF-alpha of the novel cytokine gro (melanoma growth-stimulating activity). Gro mRNA was expressed at levels 100-fold above background within 45 min of exposure to either IL-1 or TNF-alpha, in growing or serum-starved cells and a similar response was shown by IL-6. In contrast, as shown previously, gro mRNA was elevated only 10-fold by serum in starved but not in growing cells, similar to fos. Thus gro expression appears to be regulated by at least two signal transduction systems: a cytokine pathway, and a growth-related pathway. Three closely related gro genes (alpha, beta, and gamma) have been described. Their proximal 5' regulatory sequences presented here show close similarity in the region to -136, which includes the NF-kappa B site at -66 to -76 in gro alpha and gro gamma, and -64 to -74 in gro beta, and sequence diversity further upstream. Transient transfection of HeLa cells with CAT constructs localized the cytokine response to a region between -84 and -65 in gro beta. Gel retardation studies with FS-2 cells identified a cytokine-induced protein binding at the NF-kappa B site in all three gro genes as shown by competition studies with a pair of oligonucleotides representing wild-type and mutant sequences of the NF-kappa B binding site. Neither serum nor PMA induced a detectable gel shift at NF-kappa B or upstream to position -723. These results demonstrate conservation of the cytokine response element, NF-kappa B, in the three genes, consistent with the conservation of sequence in this region; and suggest that differential expression of the three gro genes may depend upon interactions with other sites located in the divergent upstream region.
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PMID:An NF-kappa B-like transcription factor mediates IL-1/TNF-alpha induction of gro in human fibroblasts. 190 1

The N-linked sugar chains of melanoma cell membrane from five murine B16 melanoma clones (F1, F10, BL6, W1-4, and C4-1) with different degrees of metastatic abilities after intravenous and intrafootpad injections were released quantitatively as oligosaccharides by hydrazinolysis, and their structures were analyzed by serial lectin column chromatography, Bio-Gel P-4 column chromatography, and sequential glycosidase digestion. Sugar chain structures of each clone have shown to consist of the same elemental oligosaccharides, but to differ in their percent compositions. More than 84% of the neutral oligosaccharides were high mannose-type sugar chains. Most complex-type sugar chains were sialylated, of which the major structure was tetraantennary sugar chain. Highly lung-colonizing F10 cells had 1.4 and 1.7 times more non-repeated tetraantennary sugar chains than moderately colonizing F1 and C4-1 cells, respectively, and 2.5 times more than poorly colonizing W1-4 cells. BL6 cells, which are also highly lung-colonizing, had 1.5 and 1.9 times more non-repeated tetraantennary sugar chains than F1 and C4-1 cells, respectively, and 2.8 times more than W1-4 cells. These results suggest that increase of sialylated tetraantennary complex-type sugar chains without N-acetyllactosamine repeating units of B16 melanoma cells might correlate with the higher lung-colonizing ability after intravenous injection.
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PMID:Increase of sialylated tetraantennary sugar chains in parallel to the higher lung-colonizing abilities of mouse melanoma clones. 194 Apr 47

This study examined the pathophysiological role of parathyroid hormone-related protein (PTHrP) in humoral hypercalcaemia of malignancy (HHM). Seven human tumour xenografts were analysed in nude mice; five tumours (KEsC-2, oesophageal carcinoma; FA-6, pancreatic carcinoma; SEKI, melanoma; Lu-65A and Lu-61, lung carcinomas) were associated with hypercalcaemia and two tumours (MIA PaCa-2, pancreatic carcinoma; PLC/PRF/5, hepatocellular carcinoma) with normocalcaemia. Northern blot analyses, radioimmunoassay and bioassay confirmed the synthesis of PTHrP-like peptides by all five tumours associated with hypercalcaemia, but not by the two associated with normocalcaemia. These observations indicated a very close relationship between the production of PTHrP and the development of HHM. Gel filtration studies of three tumour tissue extracts revealed at least two different molecules with both PTHrP-like immunological and biological activities. One peak eluted at a position between PTHrP (1-141) and cytochrome C and the other at a position identical to cytochrome C. These results suggest that PTHrP molecules with a molecular size equal to or greater than cytochrome C participate as causative agents of HHM. All five tumour xenografts caused hypercalcaemia when grown to a size of 1.5 g in nude mice. Under cell culture conditions, four original cell lines, KEsC-2, FA-6, SEKI and Lu-65A secreted 450.0, 45.0, 3.6 and 3.0 pmol of immunoreactive PTHrP/1.5 x 10(9) cells (approximately equivalent to 1.5 g wet weight) 24 h-1 into their respective culture media. Since a subcutaneous infusion of 100 pmol 24 h-1 of PTHrP (1-34) into nude mice was sufficient to induce significant hypercalcaemia, we speculate that PTHrP alone released from tumour cells could induce hypercalcaemia at least in the case of KEsC-2, and possibly in FA-6. With regard to other tumours associated with hypercalcaemia, further examination of PTHrP and other compounds with bone-resorbing activity in these transplantable tumours is required to obtain a better understanding of this morbidity.
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PMID:Production of parathyroid hormone-related protein in tumour xenografts in nude mice presenting with hypercalcaemia. 199 2

To probe the effects of N-glycosylation on the fibrin-dependent plasminogenolytic activity of tissue-type plasminogen activator (t-PA), we have expressed a human recombinant t-PA (rt-PA) gene in Chinese hamster ovary (CHO) cells and in a murine C127 cell line. The resulting rt-PA glycoproteins were isolated and their associated N-linked oligosaccharide structures determined by using a combination of high-resolution Bio-Gel P-4 gel filtration chromatography, sequential exoglycosidase digestion, and methylation analysis. The results show that CHO rt-PA is N-glycosylated differently from murine C127 derived rt-PA. Further, both rt-PA's are N-glycosylated differently from t-PA derived from a human colon fibroblast and the Bowes melanoma cell line (Parekh et al., 1989), confirming that N-glycosylation of the human t-PA polypeptide is cell-type-specific. Both CHO and murine rt-PA were fractionated on lysine-Sepharose chromatography. The N-glycosylation of the major forms was analyzed and their fibrin-dependent plasminogenolytic activity determined by using an indirect amidolytic assay with Glu-plasminogen and a chromogenic plasmin substrate. The results suggest that the various forms of rt-PA differ from one another with respect to the kinetics of their fibrin-dependent activation of plasminogen. Together, these data support the notion (Wittwer et al., 1989) that N-glycosylation influences the fibrin-dependent catalytic activity of t-PA and that t-PA when expressed in different cell lines may consist of kinetically and structurally distinct glycoforms.
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PMID:N-glycosylation and in vitro enzymatic activity of human recombinant tissue plasminogen activator expressed in Chinese hamster ovary cells and a murine cell line. 251 93

Forty-one human tumour cell lines were examined for the production of epidermal growth factor (EGF)/transforming growth factor (TGF)-alpha-like activity (EGF/TGF-alpha-LA), immunoreactive (IR-) EGF and IR-TGF-alpha. EGF/TGF-alpha-LA was determined by radioreceptor assay, in which the factors with capacity to bind to EGF receptor could be detected. IR-EGF and IR-TGF-alpha were determined by the respective radioimmunoassays. Both EGF/TGF-alpha-LA and IR-TGF-alpha were detected in 11 tumour cell lines. The levels of EGF/TGF-alpha-LA correlated well with those of IR-TGF-alpha. A small amount of IR-TGF-alpha was detected in five other lines. In contrast, IR-EGF was not detectable in any of the 41. Consequently, it can be concluded that EGF/TGF-alpha-LA produced by human tumour cells is mainly TGF-alpha rather than EGF. It was also revealed that melanoma cell lines produce a large amount of TGF-alpha frequently. Gel filtration studies revealed that TGF-alpha produced by melanoma cell lines was identical to human (h) TGF-alpha(1-50), except for one line, in which IR-TGF-alpha with a different molecular size was detected. Northern blot analysis revealed that bands corresponding to hTGF-alpha mRNA were present in melanoma cell lines producing a large amount of IR-TGF-alpha, indicating that the TGF-alpha produced is the product of hTGF-alpha gene. Further studies are required to discover the actual biological roles of TGF-alpha produced by melanoma cells as well as other types of cancer cells.
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PMID:Production of transforming growth factor-alpha in human tumour cell lines. 273 10

Autocrine-secreted tumor cell growth-inhibiting activities were isolated from supernatants of a malignant melanoma cell line, HTZ 19-dM, established from a central nervous system melanoma metastasis. HTZ 19-dM was characterized by cyto- and immunocytochemistry and karyotyping; cells were propagated in defined serum-free tissue culture medium for up to 8 months. Supernatants were ultrafiltrated, dialyzed, lyophilized, and purified by Bio-Gel P-10 gel permeation chromatography, leading to three active fraction pools, MIAI [melanoma-inhibiting activity (MIA), 2 kDa), MIAII (Mr 11,500-17,000) and MIAIII (proteins at the cutoff of Bio-Gel P-10) inhibiting growth of 19-dM cells with 50% inhibitory concentrations of 0.79 microgram/ml (MIAI), 0.13 microgram/ml (MIAII), and 16.7 micrograms/ml (MIAII). MIAII could be further purified by reverse phase high pressure liquid chromatography; the main activity displayed a 50% inhibitory concentration of 0.33 microgram/ml. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis one major band (molecular weight about 14,000) and two minor bands (up to Mr 17,000) were identified. Macromolecular synthesis was inhibited in 19-dM cells up to greater than 99.5%; tumor stem cell colony formation was reduced by 99.89%; the inhibitory effect of MIAII was irreversible, nonsaturable, and partially antagonized by a serum factor (depending on purification stage). MIAII was heat stable (3 min at 100 degrees C) and trypsin labile. The effect of MIAII on allogeneic neuroectodermal tumors was also investigated; proliferation of two of three malignant melanomas and two of four glioblastomas was inhibited up to 85.2%; proliferation of a neuroblastoma cell line could be inhibited to 33.8%, whereas normal fibroblasts and low grade gliomas were not influenced in their proliferation.
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PMID:Autocrine tumor cell growth-inhibiting activities from human malignant melanoma. 276 2

A low Mr human transforming growth factor (TGF) present in melanoma patients' urine has been purified approximately 200,000-fold to apparent homogeneity. Initial purification of an acid-soluble fraction of urine was achieved by Bio-Gel P-30 gel filtration chromatography in 1 M acetic acid. TGF activities were demonstrated in the Mr ranges of 30,000 and 6,000-10,000. These competed with epidermal growth factor (EGF) for binding to A431 membrane receptors and induced anchorage-independent growth of untransformed fibroblasts. The low Mr TGF activity obtained from P-30 chromatography was purified to apparent homogeneity by two sequential reverse-phase high performance liquid chromatography steps with a mu Bondapak C18 column first using a linear gradient of acetonitrile going from 0-60% in 120 min and then by rechromatography of the activity over the same column using a shallower gradient of acetonitrile going from 20-40% in 160 min. The isoelectric point of the melanoma patient-derived urinary TGF was determined to be 6.2, which is distinct from that for human EGF. Amino acid composition analysis of the purified urinary TGF (uTGF) revealed that it is composed of at least 42 amino acid residues with a minimum estimated Mr of 4,545. Compositional analysis further revealed distinct similarities and differences between the uTGF, human EGF and TGFs secreted by various transformed human and rodent cell lines.
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PMID:Purification and characterization of a low molecular weight transforming growth factor from the urine of melanoma patients. 299 Dec 38


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