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)

Asparaginase [EC 3.5.1.1.] of Escherichia coli, an anti-tumor enzyme, was inactivated in a time-dependent fashion by mushroom tyrosinase [EC1.14.18.1.]. The inactivation did not proceed, however, when heat-inactivated tyrosinase was used. Exculusion of the atmospheric oxygen or addition of diethyldithiocarbamate, a copper selective chelating agent, prevented the inactivation. The difference absorption spectrum of tyrosinase-inactivated asparaginase versus intact asparaginase exhibited the appearance of marked absorption peaks at 300 and 350 nm. These results indicate that the tyrosyl residue(s) of asparaginase, which is essential for the activity is enzymatically modified by tyrosianes.
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PMID:Studies of enzyme-catalyzed modification of proteins. I. Tyrosinase-catalyzed modification of asparaginase. 81 77

The per-capita intakes of zinc, cadmium, copper and of chromium were estimated from food consumption data in 28 countries and were found to correlate directly with the age-corrected mortalities from cancers of intestine, prostate, breast, leukemia, skin and of other organs, suggesting that the anticarcinogenic effect of selenium is counteracted by other trace elements. Similarly calculated dietary intakes of manganese are inversely correlated, particularly with the mortalities from cancer of pancreas, an organ normally known to contain high concentrations of this element. Arsenic intakes correlate inversely with the male lung cancer mortalities. A number of other direct and inverse associations were observed which suggest that trace elements in the human diet may hav both benign and adverse effects on tumor development. The zinc concentrations in whole blood collected from healthy donors in the U.S. correlate directly with regional mortalities from cancers of intestine, breast and of other sites. The origin of these associations is discussed primarily in terms of the seleium-antagonistic effect of zinc and of some of the other elements considered. Results of animal experiments and of other studies are cited which support hypotheses that link human cancer development to possible deficiencies or excesses in the dietary trace element intakes.
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PMID:Cancer mortality correlation studies--IV: associations with dietary intakes and blood levels of certain trace elements, notably Se-antagonists. 85 92

L-Asparaginase (L-asparagine amidohydrolase, EC 3.5.1.1) B from Acinetobacter calcoaceticus has been purified by precipitation with streptomycin, chromatography on DEAE-cellulose and CM-cellulose, gel filtration on Agarose and chromatography on phosphocellulose. The molecular weight of the enzyme was found to be 130 000. The enzyme was rather insensitive to pH changes between 7 and 9. The Michaelis constant was 3-10(-3) M. Hg2+, Cu2+, and Ni2+ as well as high ionic strength inhibited the activity of the enzyme, whereas citrate seemed to stimulate the activity. The enzyme catalyzed the deamination of L-glutamine to about the same extent as L-asparagine. The temperature stability of the enzyme is also reported. The enzyme had a weak tumor inhibitory power.
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PMID:Purification and properties of L-asparaginase B from Acinetobacter calcoaceticus. 93 83

Serum copper determinations were routinely performed in 141 men and 100 women with histologically verified Hodgkin's disease, admitted to the Radium Centre for Jutland over a 10-year-period from January 1, 1963, to January 1, 1973. The previously described variations in serum copper with the activity of the disease, increasing with progression and decreasing with improvement, were amply substantiated. Furthermore, the present study showed that the serum copper value at the first admission, before treatment, is statistically significantly correlated to the stage of the disease and consequently probably to the amount of tumor tissue. In men there was also a statistically significant correlation of se Cu to the histologic grade of the bioptic material (classification according to Lukes 1966). In women the correlation was blurred by the effect on serum copper of estrogen, mainly from contraceptive pills and pregnancy. The serum copper is regularly reduced to within normal limits at complete remission; thus, it is proposed that this parameter be included in the criteria for complete remission.
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PMID:The clinical usefulness of serum copper determinations in Hodgkin's disease. A retrospective study of 241 patients from 1963-1973. 94 17

In an epidemiological study in the Neubrandenburg district among 316 long-term exposed pesticide workers the incidence of tumors was investigated. There were 30 cases of tumors, of which 11 were lung cancers. The incidence of lung cancers was in contrast to age-specific population twenty times higher. The average exposure against pesticides amounted to 14.1 +/- 4.7 (6-23) years, the latency period between exposition start and tumor manifestation to 17.9 +/- 6.0 (6-23) years. The exposure occurred mainly to the following agents: herbicides, such as derivatives of phenoxyacetic acid (2,4 D and MCPA); insecticides, such as chlorinated hydrocarbons (DDT, HCH and Toxaphen), organic phosphorus compounds (Parathion) and organic nitro derivatives (DNOC) as well as fungicides, such as copper containing and organic synthetic agents. Between 1950 and 1956 some pesticide workers were also exposed to arsenic containing agents. As the workers were exposed to various chemical compounds simultaneously or alternatively, no carcinogenic effect can be determined by specific individual pesticides. The investigations are discussed in detail on the today knowledge about cancer hazards associated with exposure to pesticides, and respective conclusions are drawn for preventive measures.
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PMID:[High incidence of lung cancer in persons with chronic professional exposure to pesticides in agriculture (author's transl)]. 102 29

The respiration of Ehrlich ascites tumor cells is inhibited by 3-ethoxy-2-oxobutyraldehyde bis (thiosemicarbazanato) copper (II). State 3 oxidative phosphorylation in mitochondria from tumor cells is also inhibited, with the effect more pronounced using glutamate or pyruvate-malate as substrates than with succinate. The disruption of oxidative phosphorylation in bovine heart mitochondria is qualitatively similar. The principal site of inhibition is in coupling site one, energetically between the electron transport site chain and the locus of uncoupling by 2,4-dinitrophenol. This appears to contain thiol groups which are oxidized by the complex. For a series of bis (thiosemicarbazonato) copper complexes, the extent of inhibition of heart mitochondrial oxidative phosphorylation is correlated with the reduction potentials of the complexes and with their in vitro cytotoxic effects against Walker 256 carcinoma tumor cells.
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PMID:Reactions of bis(thiosemicarbazonato) copper(II) complexes with tumor cells and mitochondria. 105 15

The inadequacies of traditional methods for control of advanced oral carcinomas at their sites of origin prompted evaluation of combined chemotherapy and cryosurgery in seventy-three patients treated since 1969. Our experience with thirty-nine unlikely candidates for salvage by other therapy is the subject of this report. The majority had recurrent disease after other therapy. The observed morbidity potential of combined chemotherapy and cryosurgery with earlier experience led to abbreviations and refinements of method that are described and consist mainly of the following. (1) A two day postcryosurgical infusion (intra-arterial) of 5-fluorouracil (1 gm per twenty-four hours, or less) in lieu of methotrexate, the systemic toxicity and therapeutic efficacy of which seem less predictable with cryosurgery. (2) Electrosurgical subtotal tumor resection at the time of initial cryosurgery to reduce swelling and magnitude of in situ tissue slough. (3) Use of a flexible copper mesh cryoprobe that enhances feasibility of in-depth wide field cryosurgery. (4) Systematic use of multiple marginal wound biopsies as a principal guide to repetitive cryosurgery or other therapeutic adjunct selection. A special warning that available toxicologic data for independent drug therapy may not be applicable in patients after cryosurgery is given. Current experience indicates that negative biopsy after such combined therapy may be 85 per cent reliable in foretelling lesion outcome. Among the thirty-nine patients reported, twenty remain alive from six months to six years, only two of whom have clinically evident recurrent disease. If such could be reasonably accomplished, comparative evaluation of single methods should precede attempts to combine two or more modes of therapy. Since neither chemotherapy nor cryosurgery, as known today, can eliminate nodal metastases, each must be regarded as potentially adjunctive to other methods for achieving the ultimate goal of a cancer-free patient. It is within this context that combined chemotherapy and cryosurgery have been applied to unfavorable candidates for cure with seemingly worthwhile gains. Potential applicability for patients with less formidable stages of disease cannot be extrapolated from this experience. Large scale controlled clinical trials must provide the ultimately conclusive test of efficacy for such combined forms of therapy before decisive revision of traditional standards of practice might result.
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PMID:Combined chemotherapy and cryosurgery for oral cancer. 108 43

Copper and iron in blood of 83 women with maligne tumors of the genitalia were regulary controled before, during and till 69 weeks after therapy. The relation between the copper/iron-ratio and the expansion and histology of the tumors, the success of the therapy and the incidence of a recurrence was checked for any significancy. Our results show the improtance of the ratio in the diagnosis and differentialdiagnosis of the ovarian-cancer and the corpus-uteri-cancer, and in the success-controll during tumor-therapy. In the group of the patients with collum-uteri-cancer we found a significant difference in the copper/iron-ratio of the patients with and without a recurrence during the controllperiod after therapy, which emphasizes the importance of this copper/iron-ratio.
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PMID:[The serum copper/serum iron ratio in malignant tumors of the female genitalia]. 117 4

Seven para-substituted [phenylglyoxal bis(4-methyl-3-thiosemicarbazone)]copper (II) chelates (12-18) have been designed, synthesized, and tested for their ability to inhibit the respiration of rat liver slices as a normal cell model and Ehrlich ascites cells as a tumor cell model. Relationships between chemical structure and respiratory inhibition are described on a quantitative basis using substituent contants (pi, Es, and sigmap) by computerized multiparameter regression analyses. The correlations indicate that changes in Es have the largest effect on liver slice toxicity of chelates while pi and sigmap account for most of the variation in toxicity to ascites cells. A comparative analysis strongly suggests that electron-donating substituents with greater water solubility should increase cytotoxicity to ascites cells at the expense of cytotoxicity to the rat liver cells. The predictions of the equations were checked by synthesizing and testing an additional derivative. The results strengthen the initial predictions.
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PMID:Comparative analysis of the cytotoxicity of substituted (phenylglyoxal bis(4-methyl-3-thiosemicarbazone)) copper (II) chelates. 124 35

The cytotoxicity of copper and iron complexes of 5-substituted 2-formylpyridine thiosemicarbazones against Ehrlich ascites tumor cells has been measured. Brief in vitro incubation of cells and drugs is followed by implantation into host mice. Subsequent degree of tumor development is a measure of cytotoxicity. A spectrum of activities for the iron complexes is observed, starting with the least active as designated by its 5-substitution: OH less than OCOCH3 approximately N(CH3)2 less than H less than CH3 approximately Cl approximately CF3. The last three complexes can prevent completely tumor growth in the new host. Copper complexes of 5-H and 5-CH3 also prevent successful tumor cell transplantation.
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PMID:Inhibition of tumor cell transplantability by iron and copper complexes of 5-substituted 2-formylpyridine thiosemicarbazones. 124 18


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