Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A clone of Cloudman S91 murine melanoma was fused in vitro with non-malignant hamster cheek pouch cells by means of lysolecithin, and the putative hybrid progeny cells, HCP-MM, were found to be highly malignant in hamster, but not in appropriate mice. A malignant clone of HCP-MM cells was shown to have hamster species-specific surface antigens (as demonstrated by immunofluorescence and the cytotoxic antibody) and hamster-like lactate dehydrogenase and NAD-dependent malate dehydrogenase isoenzyme profiles. Nevertheless, chromosomes similar to those of both murine and hamster parental cells could be distinguished in cells of this malignant clone and in hamster tumor grafts by the method of trypsin-Giemsa banding. A majority of the murine chromosomes, however, appeared to be lost. This study indicates that a murine melanoma previously found untransplantable in hamsters could produce a highly malignant and lethal tumor for hamsters after being mixed in vitro with non-malignant hamster cells, in the presence of a fusing chemical. It is not as yet certain whether the production of transformed cells in vitro and of highly malignant tumors in the hamster (both with predominantly hamster properties) required heterosynkarion formation between the murine melanoma and hamster cheek pouch cells. Nevertheless, our results suggest that the presence of the murine melanoma, and possibly the interaction of its genome with non-malignant hamster cells, was implicated in this process.
Int J Cancer 1975 Feb 15
PMID:Oncogenesis by interspecific interaction of malignant murine and non-malignant hamster cells in vitro. 109 20

The effect on tumor progression produced by the injection of VCN-treated tumor cells in dogs with spontaneous mammary tumors was investigated. Untreated dogs of different races and different ages with at least two palpable spontaneous mammary tumors were selected. One of the tumors was left in the animal for further clinical examination whereas the other tumor(s) was (were) excised for preparation of a single-cell suspension by mechanical disintegration and enzymatic digestion with collagenase and trypsin. (1) In the first group, each animal was infected with 2 times 10-7 similarly prepared autologous, mitomycin-treated tumor cells; in 8 out of 12 dogs of this group the tumors progressed while so far 1 dog has died of metastasis. (2) In the second group, each animal received the same number of 2 times 10-7 tumor cells, which were mitomycin- and VCN-treated: 13 out of 15 dogs had a significant regression of their tumors to less than 10% of the original volume; in 1 dog the tumor remained unchanged and in 1 dog it progressed. (3) In the third group, 8 dogs received 1 times 10-8 mitomycin- and VCN-treated tumor cells: the application of this cell dose resulted in an accelerated tumor progression in all 8 dogs, 3 of which have already died of metastasis. The significance of these findings, with respect to potentiation and abrogation of the immunological response and with regard to immunotherapy in man, is discussed.
Int J Cancer 1975 Mar 15
PMID:Regression of spontaneous mammary tumors in dogs after injection of neuraminidase-treated tumor cells. 114 Aug 60

Goat-antimouse (DBA/2) SL2 lymphoma immunoglobulin was specifically cytotoxic to DBA/2-derived sl2 lymphoma cells. This anti-SL2 immunoglobulin, or a part of it, was cytophylic for peritoneal macrophages as shown by target cells adhering to macrophages incubated in vitro with the immunoglobulin. The target cells became free in the medium after incubation with 0.1% trypsin for 1 hour. In in vivo experiments, the incubation of immune or hyperimmune peritoneal cells with immunoglobulin from normal goat serum or from goat-anti-SL2 serum before use in immunotherapy decreased the number of DBA/2 mice surviving for more than 35 days an intraperitoneal injection with SL2 cells compared to the number of survivors inoculated with immune or hyperimmune cells only. These results show that, in immunotherapy with immune cells, we must consider the possibility that specific antitumor antibodies and antibodies not directed against the tumor cloud the therapeutic potnecy of the immune cells.
J Natl Cancer Inst 1975 Jan
PMID:Therapy with antibody-coated immune and hyperimmune peritoneal cells in a murine lymphoma system. 116 95

Fibroblasts underlying human uterine cervical dysplasia, carcinoma in situ, and invasive carcinoma are agglutinable by concanavalin A (Con A) but not by wheat germ agglutinin, except at very high concentration. Studies with low levels of Con A show that maximal agglutination is obtained with fibroblasts from invasive carcinoma, while the fibroblasts underlying dysplasia give minimal agglutination reactions. Fibroblasts underlying carcinoma in situ give agglutination reactions halfway between those obtained with fibroblasts underlying dysplasia and invasive carcinoma. An epithelial-like cell line obtained from a case of dysplasia shows agglutinability by Con A very similar to that obtained with fibroblasts underlying dysplasia. These epithelial-like cells are also not agglutinable by wheat germ agglutinin. Treatment of the cervical cells, both epithelial and fibroblasts, with neuraminidase leads to slight increase in agglutination by both Con A and wheat germ agglutinin. Marked increase in agglutination is not obtained even after treatment with high concentration of neuraminidase (10 units/10(6) cells). Marked agglutinability, however, is observed after trypsin treatment. The results suggest that, while the fibroblasts obtained from normal cervix are not agglutinable by Con A, surface alterations necessary for Con A-specific agglutination exist in fibroblasts during the early stage of development of uterine cervical epithelial neoplasia (dysplasia) and increase with the progression through carcinoma in situ to invasive carcinoma. Loss of cell surface sialic acids may result in a slight increase in agglutinability, but some other mechanism(s) is likely to be involved in alteration of surface properties that lead to marked agglutinability of the human uterine cervical cells obtained from cancer precursor lesions.
Cancer Res 1975 Sep
PMID:Different agglutinability of fibroblasts underlying various precursor lesions of human uterine cervical carcinoma. 117 Sep 43

Murine solid tumors were shown to contain 9-54% medium to large non-malignant cells bearing receptors for immunoglobulin Fc. These cells rapidly adhered to plastic surfaces, were trypsin-resistant, were capable of phagocytosis of latex particles and were sensitive to the lytic effects of anti-macrophage serum and complement. Purified Fc-receptor-positive cells failed to produce tumors, which strongly suggested that they were macrophages. When tumor-cell suspensions, depleted of macrophages by adherence to plastic surfaces, were injected subcutaneously into normal syngeneic mice, the tumors displayed an increased potential for metastasis. By contrast, control animals which received tumor-cell suspensions containing their normal complement of macrophages invariably developed progressive localized tumors. The survival times of mice infected with macrophage-depleted tumor-cell suspensions were significantly shorter (p less than 0.05) than those for animals inoculated with intact tumor-cell suspensions. These studies confirm the existence of a substantial number of macrophages within progressing syngeneic murine solid tumors and strongly suggest a regulatory role for the macrophages in the growth and metastasis of the tumor.
Int J Cancer 1975 Dec 15
PMID:Studies on the role of macrophages in regulation of growth and metastasis of murine chemically induced fibrosarcomas. 120 71

A major cell-surface glycoprotein of the TA3-Ha ascites mammary adenocarcinoma diminished during transfer from ascites growth to cell growth in suspension culture. A sensitive, hemagglutination-inhibition assay that used a lectin from Vicia graminea seeds indicated approximately a 50% loss after 7-10 days of culture and a 90% loss after 2 months. These findings were corroborated by carbohydrate and amino acid analysis with gas-liquid chromatography of trypsin glycopeptides released from the cell surface. Repassage of the cultured cells in vivo caused the reappearance of the surface glycoprotein.
J Natl Cancer Inst 1975 Nov
PMID:Reversible loss in suspension culture of a major cell-surface glycoprotein of the TA3-Ha mouse tumor. 123 14

Several of the cannabinoids found in marihuana have been shown to inhibit tumor growth and increase the life-span of mice bearing the Lewis lung adenocarcinoma. When trypsin-dispersed isolated Lewis lung cells are incubated in vitro, they maintain their capacity to carry out macromolecular synthesis (RNA, DNA, protein). This process can be inhibited by cytosine arabinoside, actinomycin D, or methyl-1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea, whereas cyclophosphamide, an agent that must be bioactivated, was inactive. Inhibition of DNA synthesis as measured by [3H]thymidine uptake into acid-insoluble material was used as an index of cannabinoid activity against isolated Lewis lung cells, L1210 leukemia cells, and bone marrow cells incubated in vitro delta9-, delta8-, 1-hydroxy-3-n pentyl-, and 1-delta8-tetrahydrocannabinol, and cannabinol demonstrated a dose-dependent inhibition of DNA synthesis whereas cannabidiol and 1-hydroxy-3-n-pentylcannabidiol were markedly less inhibitory in our in vitro cell systems. Furthermore, our in vitro observations with these cannabinoids are supported by in vivo tumor inhibition studies. Ring modifications as in cannabichromene or cannabicyclol abolish in vitro activity as does dihydroxylation at the 8beta and 11 positions of 1-delta9-trans-tetrahydrocannabinol. Delta9-trans-tetrahydrocannabinol demonstrated the least toxicity of all inhibitory cannabinoids in vivo; this is supported by its lesser effect on bone marrow DNA synthesis in vitro.
Cancer Res 1976 Jan
PMID:The inhibition of DNA synthesis by cannabinoids. 124 11

Two murine colon adenocarcinoma cell lines were established from primary cultures. The MCA-38 cell line was begun by treatment of the primary culture with trypsin to remove the fibroblastoid elements. The MCA-36 epithelial cells were sensitive to trypsin; therefore, the growth medium of MCA-36 primary cultures was augmented with collagenase to release the tumor-cell elements from the fibroblast network. These tumor elements were dissociated with trypsin and placed in tissue culture. Each cell line was cultured for at least 10 passages in vitro and gave rise to tumors when reimplanted in vivo.
J Natl Cancer Inst 1976 Apr
PMID:Murine colon adenocarcinomas: methods for selective culture in vitro. 125 4

The relationship between serum and tumour cell surface proteolytic enzymes and the development of muscle breakdown in cancer cachexia has been studied in a murine model of the condition (MAC16). The surface of the MAC16 tumour cells carried a proteolytic enzyme referred to as guanidinobenzoatase (GB). Serum from mice also contained an enzyme (referred to as MSE) which cleaved the trypsin inhibitor 4-methylumbelliferyl-p-guanidinobenzoate as a true substrate, but there was no relationship with weight loss or the presence or absence of tumour and the level of this serum enzyme. Polyunsaturated fatty acids (PUFAs) were shown to be inhibitors of MSE at microM concentrations and one PUFA, eicosapentaenoic acid (EPA) was found to be a non-competitive inhibitor of both MSE and GB. The effect of EPA was specific since other proteolytic enzymes, trypsin, esterase and tissue plasminogen activator were unaffected by concentrations inhibiting GB and MSE. MSE and GB are two different enzymes which possess some common properties. However, GB is likely to be significant for tumour development since MSE is also found in normal mouse serum.
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PMID:Observations on the inhibition of serum and cell surface enzymes by eicosapentaenoic acid. 128 67

Normal rabbit serum contained two kinds of growth-inhibitory protein, GI-I and GI-II, in latent forms. These latent inhibitors were activated by incubation at 37 degrees C for 12 h, and their activation was lowered by inhibitors for serine, cysteine and metalloproteinases. Both growth inhibitors were highly purified in active forms by successive column chromatographies. GI-I showed a major protein band with an Mr of 18,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, while GI-II showed a major protein band with an Mr of 36,000. GI-I and GI-II half-inhibited the growth of rat tumorigenic cell line (RSV-BRL) at concentrations of 0.5 ng/ml and 10 ng/ml, excess concentrations. Of the 15 cell lines tested, GI-I specifically inhibited the growth of rodent and lagomorph cells, whereas GI-II nonspecifically inhibited the growth of all cell lines tested. Specificities for cell type and malignancy were not observed with either inhibitor. These growth inhibitors were stable to a reducing reagent and proteinase inhibitors, but labile to urea, acid, organic solvents, trypsin, plasmin and heating at 95 degrees C for 5 min. These properties suggested that both growth inhibitors might be distinct from known growth-inhibitory factors.
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PMID:Purification and partial characterization of two types of growth-inhibitory protein latently present in rabbit serum. 137 Oct 74


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