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)

L-Asparagine synthetase appears in serum approximately 7 days after the s.c. implantation of 1 X 10(5) cells of Leukemia 5178Y/AR (resistant to L-asparaginase) and increases in activity as the neoplasm grows and metastasizes. The principal source of the enzyme is the primary tumor. After intravranial inoculation of tumor, the rate of leakage of the enzyme is more pronounced than when the subcutaneous, intramuscular, or intraperitoneal routes are used. 1-(2-Chloroethyl)-3-cyclohexyl-1-nitrosourea (NSC 79037), a nitro-sourea effective in the palliation of L5178Y/AR, temporarily halts the influx of enzyme into the blood stream, as does surgical excision of the s.c. tumor nodules. Treatment of mice with L-asparaginase within 24 hr of inoculation of the tumor markedly augments both tumor growth and the rate of penetration of L-asparagine synthetase into the circulation. Several other L-asparagine synthetase into the circulation. Several other L-asparaginase-resistant tumors also were found to spill L-asparagine synthetase into the serum, but the correlation between this phenomenon and the specific activity of the enzyme in homogenates of the tumor was imperfect.
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PMID:L-Asparagine synthetase in serum as a marker for neoplasia. 1 81

Recently we reported that the highly metastatic MSC-10 (mouse squamous carcinoma) is incapable of inducing transplantation immunity. Studies reported here were undertaken to determine whether or not the tumor is devoid of tumor-associated antigen. We found that sera from MSC-10 tumor-bearing mice contain soluble protein antigens which react with rabbit antisera made against the MSC-10 tumor, as demonstrated by immuno-diffusion. Such proteins were not detected in the sera of normal mice or mice bearing fibrosarcomas. A close temporal relationship was demonstrated between the appearance of circulating antigens and the occurrence of lung metastases. Protein components serologically indistinguishable from the circulating antigens were isolated from tumor cells. The molecular weight of these proteins is between 30,000 and 100,000 daltons. Studies with antisera to mouse leukemia virus showed that hte MSC-10 tumor antigens are not viral proteins. The lack of immunogenicity of this tumor for syngeneic hosts as well as its high metastatic activity may be due to the early appearance of soluble antigens in the circulation.
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PMID:Detection of circulating tumor antigens in mice carrying a highly metastatic pulmonary squamous--cell carcinoma. 7 59

A proportion of cancers in endocrine target tissues can show the presence of specific receptors for either steroid or polypetide hormones. Manipulation of the controlling hormones does not guarantee regression. A third of cancers in endocrine target organs (breast, uterine endometrium, and prostate) show a 50% reduction in size of lesions after hormonal therapy. If regression resulting from an aggressive form of therapy lasts a short while and the tumor reactivates by the time the unpleasant effects of the therapy wear off, the treatment is not palliative. Endocrine therapy in prostatic cancer is palliative but there is no evidence that is increases survival. 11 different progestational agents in endometrial cancer therapy in the past 25 years resulted in a 30-35% response. Response must be maintained by continual treatment and may last from 12 months to 7-8 years. In breast cancer, tumors with a significant level of estrogen receptor (ER+) have about a 60% chance of regression vs. tumors without estrogen receptors (ER-), 10%. Advanced cancers of the thyroid of the papillary or follicular type regress when the patient is treated by thyroxine, .3 mg daily. Leukemia and lymphoma are frequently treated, with varying degrees of success with corticosteroid therapy, which may also predispose the patient to intercurrent infection. Renal cancer has been often treated by medroxyprogesterone acetate or testosterone propionate, with little success.
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PMID:Endocrine therapy in cancer. 8 86

Aclacinomycin-A is a new anthracycline glycoside and has less cardiotoxicity than adriamycin. In an attempt to provide an experimental model of a phase III study of aclacinomycin-A, particularly for the treatment of malignant lymphomas, various therapeutic designs of combinations of this drug with other conventional agents were investigated using a P388 mouse leukemia system. Aclacinomycin-A showed no treatment schedule dependency in this tumor system and the optimal dosage of this drug was twice higher than that of adriamycin on each treatment schedule; i.e., single treatment on day 1, three treatments on days 1, 5, and 9, or 10 treatments on every other day from days 1 to 19 after an inoculation of 10(6) leukemic cells on day 0. This antibiotic was ineffective against an adriamycin-resistant subline of P388 leukemia. Among combinations of aclacinomycin-A with cyclophosphamide, vincristine, procarbazine, or bleomycin, the combinations of aclacinomycin-A with cyclophosphamide or vincristine showed a therapeutic synergism in P388 leukemia system.
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PMID:Combination chemotherapy with a new anthracycline glycoside, aclacinomycin-A, and active drugs for malignant lymphomas in P388 mouse leukemia system. 9 32

The successive application of X-irradiation and ethylnitrosourea during the fetal period in NMRI-mice results in tumorous as well as in degenerative diseases in offspring. Leukemia and ovarial tumor incidences are increased when compared with animals either treated alone, whilst lung and liver tumors appear at a lower rate. Liver necroses and kidney cysts are further outstanding pathological findings after combined treatment. These results can be parallelled with the known postirradiational proliferative capacities of the affected fetal tissues, and possibly are a sensitive indicator for such radiation induced alterations.
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PMID:Oncogenic properties of transplacentally acting ethyl-nitrosourea in NMRI-mice after antecedent X-irradiation. 14 44

Non-produces (NP) human cells were isolated from transformed foci induced by the Kirsten mouse sarcoma virus. These morphologically altered NP cells produced neither infectious virus nor complement-fixing antigens of the murine sarcoma-leukemia virus complex. However, the sarcoma virus genome could be rescued from these NF cells by co-cultivation with cells carrying "helper" Kirsten mouse leukemia virus or Woolly Monkey leukemia virus. The possible usefulness of these cells in efforts designed to detect covert or repressed RNA tumor viruses in various animal and human tissues is discussed.
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PMID:Non-producer human cells induced by murine sarcoma virus. 16 48

Approximately 350 amino acid derivatives were synthesized and tested for antitumor activity in four tumor systems. The effect on life prolongation and tumor growth was examined using mouse leukemia SR-61, Ehrlich ascites carcinoma, ascites sarcoma-180, and rat ascites hepatoma (AH-60C). Among these 350 derivatives, 29 compounds were found to be significantly effective in prolongation of the median life-span and inhibitory effect on tumor growth in the primary screening. Among these 29 compounds, the following five compounds were found to possess potential antitumor activity: N-(2-Naphthalene)sulfonyl-DL-tryptophan (A-91), 2-naphthylaminomethyl-gamma-aminobutyric acid (A-144), N-ethylcarbaminomethyl-L-isoleucine (A-145), N-9-fluorenylacetyl-L-phenylalanine (A-192), and N-propionyl-L-valine (A-195). These five compounds were active in prolongation of the life-span of mice bearing Ehrlich ascites carcinoma and in the inhibition of the cell growth. Some of these amino acid derivatives inhibited biosynthesis of macromolecules, DNA, RNA, and protein, in tumor cells. These results suggest that the site of action of the five amino acid derivatives appears to result from the inhibition of macromolecules and another unknown mechanism.
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PMID:Antitumor activity of amino acid derivatives in the primary screening. 16 14

Plasma membranes were isolated by two methods from mouse leukemia cells containing mammary tumor virus-induced (MLr) and normal (Thy.1.2) antigens on their surfaces. A number of chemical components, enzymic activities, and the antigenic contents were determined in subcellular fractions and found to be specifically concentrated in the plasma membrane fractions. The major part of the cellular MLr, in contrast to Thy.1.2, was present in the 105,000 X gmax supernatant of the cell homogenate. This and other results indicate an easy release of the antigen from the plasma membrane. A considerable amount of MLr was also present in the ascites fluid, partly free and partly bound, supposedly in an immune complex that allowed the isolation of three components of similar molecular weights as mammary tumor virus components. The extracellular presence of MLr may illustrate that, by shedding of antigen, the tumor may protect itself against the immunological defense of the host.
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PMID:Quantitation of virus-induced (MLr) and normal (Thy.1.2) cell surface antigens in isolated plasma membranes and the extracellular ascites fluid of mouse leukemia cells. 16 66

Two murine sarcoma viruses, the Kirsten and the Harvey, were isolated by passage of mouse type C leukemia viruses through rats. These sarcoma viruses have genomes containing portions of their parental type C mouse leukemia virus genomes, in stable association with specific rat cellular sequences that we find to be quite likely not those of a rat type C leukemia virus. To determine if these murine sarcoma viruses provide a model relevant to the events occurring in spontaneous tumors, we have hybridized DNA and RNA prepared from rat tumors and normal rat tissues to [3H]DNA prepared from the Kirsten murine sarcoma virus. We have also hybridized these rat tissue nucleic acids to [3H]DNA prepared from a respresentative endogenous rat type C leukemia virus, the WFU (Wistar-Furth). Sarcoma-viral rat cellular sequences and endogenous rat leukemia viral sequences were detected in the DNA of both tumor and normal tissues, with no evidence of either gene amplification or additional sequences being present in tumor DNA. Sarcoma-viral rat cellular sequences and endogenous rat leukemia viral sequences were detected at elevated concentrations in the RNA of many rat tumors and in specific groups of normal tissues.
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PMID:Rat sequences of the Kirsten and Harvey murine sarcoma virus genomes: nature, origin, and expression in rat tumor RNA. 17 19

The activity of the malate-aspartate shuttle for the reoxidation of cytoplasmic reduced nicotinamide adenine dinucleotide (NADH) by mitochondria was assessed in six lines of rodent ascites tumor cells (two strains of Ehrlich ascites carcinoma, Krebs II carcinoma, Novikoff hepatoma, AS-30D hepatoma, and L1210 mouse leukemia). All the tumor cells examined showed mitochondrial reoxidation of cytoplasmic NADH, as evidenced by the accumulation of pyruvate when the cells were incubated aerobically with L-lactate. Reoxidation of cytoplasmic NADH thus generated was completely inhibited by the transaminase inhibitor aminooxyacetate. The involvement of the respiratory chain in the reoxidation of cytoplasmic NADH was demonstrated by the action of cyanide, rotenone, and antimycin A, which strongly inhibited the formation of pyruvate from added L-lactate. Compounds that inhibit the carrier-mediated entry of malate into mitochondria, such as butylmalonate, benzenetricarboxylate, and iodobenzylmalonate, also inhibited the accumulation of pyruvate from added L-lactate by the tumor cells. The maximal rate of the malate-aspartate shuttle was established by addtion of arsenite to inhibit the mitochondrial oxidation of the pyruvate formed from added lactate. The capacity of the various tumor lines for the reoxidation of cytoplasmic NADH via the malate-aspartate shuttle approaches 20% of the total respiratory rate of the cells and thus appears to be sufficient to account for the mitochondrial reoxidation of that fraction of glycolytic NADH not reoxidized by pyruvate and lactate dehydrognenase in the cytoplasm.
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PMID:Occurrence of the malate-aspartate shuttle in various tumor types. 17 6


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