Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Components on the surface of MM2 ascites mammary carcinoma cells induce agglutination factors in the serum of syngeneic host C3H/He mice, and bind the factors in vitro. These components have been classified into three groups: MM2-specific substances, mammary tumor virus (MTV)-associated substances and tumor-associated embryonic materials. The substances contained saccharide moieties and their terminal sugar residues were essential for the binding of the serum factors. These terminal saccharides were exposed during cell proliferation,but masked in stationary cells, at least partly, due to elongation of the saccahride moieits. The terminal structures of these polysaccharide moities of growing and stationary cells were studied by semiquantitative tumor cell agglutination using the agglutinating activities against MM2 cells of MM2-regressor serum and of FMA/R- and Ehrlich-regressor sera which had partial cross-agglutination activities. Agglutination by phytohemagglutinins, inhibition of the agglutination by saccharides or with isolated cell surface components and treatment of the cells with glycosidases were also used for this purpose.
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PMID:Humoral reactions in syngeneic hosts against tumor cell surface incomplete saccharide moieties. 94 53

Interferon gamma (IFN-gamma) production has been attributed exclusively to activated T cells and NK cells. We sought to determine whether human B cells express IFN-gamma. We studied 28 B cell lines including Epstein-Barr virus (EBV)+ normal lymphoblastoid B cell lines (N = 7), EBV+ B cell lines derived from patients with Burkitt's lymphoma with (N = 6) or without AIDS (N = 8), as well as seven EBV- B cell lines. All cell lines were studied by reverse transcription-polymerase chain reaction (RT-PCR). We detected constitutive expression of IFN-gamma in every B cell line. The tumor promoters PMA and teleocidin appeared to enhance this IFN-gamma expression in nearly every B cell line. The 517 bp amplicons spanning the entire protein coding region of the IFN-gamma mRNA from three representative lines were sequenced, definitively establishing that B cell IFN-gamma is identical to IFN-gamma from activated T cells and is not altered by derivation of the B cell lines from AIDS patients or by EBV status. Detection of IFN-gamma in the entire panel of EBV+ and EBV- cell lines suggests that the IFN-gamma gene is broadly expressed by human B cells. Our data imply that human B cells can be activated to produce IFN-gamma, further enmeshing B cells in the dynamics of immunoregulation.
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PMID:Human B cell lines express the interferon gamma gene. 129 29

Serum TAG 72 concentrations of 110 normal subjects, 110 patients with benign diseases and 109 with malignant diseases were determined by a solid phase radioimmunoassay. Its levels in normal subjects were 1.6 +/- 1.5 u/ml (mean +/- SD, range 0-8.2 u/ml) and the cut-off limit was set at 4.6 u/ml. The positive rates in benign and malignant patients were 5.5% and 48.6%, respectively. Among the malignancies, 80.0% of ovarian and 63.6% of colon carcinomas had positive test results. The specificity for differentiating malignancies from benign diseases was 94.5% and the accuracy of diagnosis was 71.7%. The present study indicates that TAG 72 as a tumor marker is helpful in the diagnosis of malignancies.
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PMID:[The value of serum tumor-associated glycoprotein 72 (TAG 72) in the diagnosis of malignancies]. 130 18

We describe in detail the current trend using monoclonal antibodies to diagnose ovarian cancer either in vitro or in vivo. The approach with such powerful reagents allows to differentiate in vitro tumor histotypes and to detect in peritoneal washings the presence of a few neoplastic cells which characterize the minimal disease. The detection of elevated sera levels of ovarian cancer-associated antigens, such as CA-125 and TAG-72, allows the monitoring, follow-up of these patients and the response to therapy with great accuracy. We focused our attention on the role in vivo of labelled monoclonal antibodies, mainly for diagnostic purposes. Radioimmunoscintigraphy has been found to be more reliable than CT and US to detect foci of disease mainly in patients already treated by surgery, overcoming all the problems usually encountered with these two procedures.
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PMID:Management of patients with ovarian cancer using monoclonal antibodies. 130 60

The effect of the relative affinity (Ka) on the antitumor efficacy of monoclonal antibodies (MAbs) has been questioned. It has previously been shown in experimental models that the use of MAbs with higher relative Kas manifests itself in a higher percentage of injected dose of MAb bound to tumor. On the other hand, mathematical models have proposed that the use of higher affinity MAbs may be disadvantageous for antitumor effects, since higher Ka MAbs would bind more antigen and prevent penetration of MAb through tumor. To test this hypothesis, three MAbs reacting to the human pancarcinoma antigen TAG-72 were used as radioimmunoconjugates for therapeutic efficacy versus the LS-174T human colon carcinoma xenograft. MAbs B72.3, CC49, and CC83 have all been shown by depletion studies to react to the same molecule and to all react with overlapping epitopes. While the relative Ka of B72.3 is 2.5 x 10(9) M-1, the relative Kas of CC49 and CC83 are 16.2 and 27.7 x 10(9) M-1, respectively. Each MAb was radiolabeled with 131I, and each radioimmunoconjugate was assayed at five dose levels for therapeutic efficacy using the human xenograft model. The results of these studies demonstrate substantial therapeutic advantage of the higher affinity MAbs CC49 and CC83 versus B72.3 at every dose level. While 500 microCi of B72.3 were required to reduce tumor growth in only a minority of tumor-bearing animals, the use of the same amount or less of the radioimmunoconjugates of CC49 or CC83 resulted in strong antitumor effects in 80 to 100% of tumor-bearing animals. Thus, stronger antitumor effects were seen using as little as 2.5- to 3-fold less of the higher Ka immunoconjugates CC49 and CC83 as compared with B72.3. While we acknowledge the potential disadvantages of higher Ka MAbs in some situations, at least the experimental studies and model system described here show that a distinct therapeutic advantage exists with the use of higher affinity immunoconjugates.
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PMID:Therapeutic advantage of high-affinity anticarcinoma radioimmunoconjugates. 131 Jun 38

The expression of tumor-associated glycoprotein (TAG-72), an oncofetal mucin-like tumor-associated glycoprotein derived from membrane-enriched fractions of metastatic breast carcinoma, has been detected by monoclonal antibody (MoAb) B72.3 in adenocarcinomas of breast, colon, lung, endometrium, pancreas, and ovary. The authors reported the scope of TAG-72 expression detected by MoAb B72.3 in salivary neoplasia. They examined 96 salivary lesions (53 malignant and 37 benign primary tumors, 2 metastatic carcinomas, and 4 other benign lesions) and 17 normal tissues from parotid glands and found: diffuse TAG-72 expression in 29 of 55 (53%) malignant tumors and 6 of 36 (17%) benign tumors and in no normal tissue; focal TAG-72 expression in 10 of 55 (17%) malignant salivary tumors, 10 of 37 (25%) benign salivary tumors (all benign mixed tumors), and 1 of 17 (6%) histologically normal parotid gland ducts. Any expression of TAG-72, whether diffuse or focal, was found to have a 71% sensitivity for detecting salivary malignant tumors, but an unacceptably low specificity for malignant lesions (57%). Alternatively, if only diffuse TAG-72 expression was regarded as indicative of malignancy, the specificity of diffuse TAG-72 expression was 86%, but sensitivity of detection decreased to 53%. The authors studied a subset of benign and malignant mixed tumors (BMT and MMT) and found that 12 of 15 (80%) MMT diffusely and strongly expressed TAG-72, 2 of 15 MMT (13%) expressed TAG-72 focally, and 1 MMT (7%) was nonreactive. By contrast, most BMT did not express TAG-72; only sparse, focal TAG-72 expression was seen in 10 of 27 (37%) BMT. If diffuse TAG-72 expression is considered indicative of malignancy, its sensitivity and specificity for malignant mixed tumors is 80% and 100%, respectively. The authors suggest that diffuse TAG-72 expression may resolve conflicts in determining whether or not a mixed tumor is malignant.
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PMID:Tumor-associated glycoprotein distribution detected by monoclonal antibody B72.3 in salivary neoplasia. 131 5

We investigated whether replication-competent pre-C/C defective mutants of hepatitis B virus (HBV) are detectable in primary human hepatocellular carcinoma (HCC) tissues from patients of a geographic area endemic for such mutants. DNAs extracted from formalin-fixed paraffin-embedded HCC samples were checked for the presence of specific HBV DNA sequences using the polymerase chain reaction (PCR). Amplified pre-C regions from nine HCC samples were directly sequenced as were samples of nontumoral liver tissues from five of these patients. The data show that hypervariable distal pre-C sequences were present in all nine HCC samples; this high variability was dependent on point mutations, which led to amino acid substitutions in nearly all cases. Interestingly, seven of the nine HBV DNA-positive samples from HCC tissues (but not samples from peritumoral liver tissue) showed mutations leading to amino acid substitution at the level of a distal cysteine residue. No mutation generating a translationally defective pre-C/C region was detectable in the tumor samples. Otherwise, in four of the six nontumoral liver tissues available from the same patients, a pre-C sequence with an in-frame TAG stop codon was detectable, although in three cases as a component of mixed population.
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PMID:Sequence analysis of the hepatitis B virus pre-C region in hepatocellular carcinoma [HCC] and nontumoral liver tissues from HCC patients. 131 86

We have cloned the cDNA for Mo3, an activation Ag expressed by human monocytes and myelomonocytic cell lines after stimulation by PMA, LPS, muramyl dipeptide, certain cytokines, and cAMP agonists. We have previously shown that Mo3 expression in vivo is associated predominantly with macrophages in inflammatory sites. Mo3 is a highly glycosylated protein of about 50 kDa in monocytes and U-937 cells and is anchored to the plasma membrane by glycosyl-phosphatidylinositol linkage. We purified Mo3 protein by cleavage from the U-937 cell surface with phosphatidylinositol-specific phospholipase C, followed by affinity chromatography using a mAb. An internal peptide sequence was determined and used to design oligonucleotide probes for screening an expression cDNA library. Nucleotide sequencing indicated that the complete coding sequence encodes 335 amino acids, including a predicted signal peptide of 22 residues and a hydrophobic C-terminal portion that is probably cleaved during formation of the GPI linkage. The resulting mature protein of about 290 amino acids is consistent with the 29-kDa molecular mass of deglycosylated Mo3. A Northern blot of RNA from U-937 cells revealed a 1.5-kb band that was induced by PMA treatment. Mo3 cDNA was transfected into Cos cells and surface expression of Mo3 was detected by ELISA using various anti-Mo3 mAb. We performed a computer search of the National Biomedical Research Foundation database and found that Mo3 is identical to the human receptor for the urokinase plasminogen activator (uPA-R). Purified soluble Mo3, as well as anti-Mo3 antibodies, were able to block uPA binding to its receptor on U-937 cells, indicating that Mo3 is indeed uPA-R. The use of these anti-Mo3 antibodies may be helpful in assessing the role of uPA-R in processes such as inflammation and tumor invasion.
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PMID:cDNA for Mo3, a monocyte activation antigen, encodes the human receptor for urokinase plasminogen activator. 131 22

Subtractive hybridization, selecting for mRNAs expressed in normal human mammary epithelial cells (NMECs) but not in mammary tumor cell lines (TMECs), led to the cloning of the human gap junction gene connexin 26 (Cx26), identified by its sequence similarity to the rat gene. Two Cx26 transcripts derived from a single gene are expressed in NMECs but neither is expressed in a series of TMECs. Northern analysis using rat Cx probes showed that Cx43 mRNA is also expressed in the normal cells, but not in the tumor lines examined. Connexin genes Cx31.1, Cx32, Cx33, Cx37, and Cx40 are not expressed in either normal cells or the tumor lines examined. In cell-cell communication studies, the normal cells transferred Lucifer yellow, while tumor cells failed to show dye transfer. Both Cx26 and Cx43 proteins were immunolocalized to membrane sites in normal cells but were not found in tumor cells. Further analysis demonstrated that Cx26 is a cell-cycle regulated gene expressed at a moderate level during G1 and S, and strongly up-regulated in late S and G2, as shown with lovastatin-synchronized NMECs. Cx43, on the contrary is constitutively expressed at a uniform low level throughout the cell cycle. Treatment of normal and tumor cells with a series of drugs: 5dB-cAMP, retinoic acid, okadaic acid, estradiol, or TGFb had no connexin-inducing effect in tumor cells. However, PMA induced re-expression of the two Cx26 transcripts but not of Cx43 in several TMECs. Thus Cx26 and Cx43 are both downregulated in tumor cells but respond differentially to some signals. Modulation of gap-junctional activity by drug therapy may have useful clinical applications in cancer.
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PMID:Transcriptional downregulation of gap-junction proteins blocks junctional communication in human mammary tumor cell lines. 132 44

Pituitary tumorigenesis occurs in a transgenic line of mice, alpha-T7, which carries a hybrid transgene composed of the 5' flanking region of the human glycoprotein hormone alpha-subunit gene (1.8 kb) linked to the coding region of the SV40 T-antigen gene (alpha-Tag). Tumor foci were identified within the anterior pituitary of both male and female transgenic mice. In addition to a parenchyma with hypertrophied endocrine cells, mostly of the gonadotrope lineage, we here report the unexpected presence of neural tissue within the anterior pituitary, either as foci as large as 1.0 mm in diameter or greater, or in delicate bundles ramifying amongst the granulated parenchymal cells. Areas richest in neural tissue frequently were associated with tumor tissue composed of giant cells of three varieties, all with electron-lucent cytoplasm and similar organellar distribution including small secretory granules (80-160 nm diameter). In type I cells, the secretory granules were aligned at the plasma membrane; in type II cells, the secretory granules were distributed throughout the cytoplasm; type III cells formed colloid-filled follicles and their secretory granules rarely exceeded 100 nm diameter. These giant cells frequently had bizarre pleomorphic nuclei intensely immunopositive for T-antigen and cytoplasm which was lightly immunopositive for alpha-subunit, and immunopositive either for the LH-beta or TSH-beta subunits. Neural tissue contacted the normal granulated parenchymal cells directly, i.e., without a basal lamina or any connective tissue intervening, but only rarely formed synaptoid junctions with these granulated cells. Synaptoid junctions containing round, smooth vesicles, as well as dense core vesicles, were numerous between the neural processes themselves and between the neural tissue and the giant cells of the tumor tissue. These data suggest that in alpha-T7 transgenic mice the giant cells represent highly transformed gonadotropes or thyrotropes, and that a neurotrophic factor may be expressed by these transformed pituitary parenchymal cells.
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PMID:Neural tissue within anterior pituitary tumors generated by oncogene expression in transgenic mice. 133 36


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