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)

The insensitivity of the natural killer (NK)-resistant L5178Y-F9 murine T-cell lymphoma to granule extracts from a rat NK leukemia could be preferentially reversed in increased NaCl (0.25 M) compared with the NK- and granule extract-sensitive SL2-5. The high salt effect predominated in the binding rather than the lytic phase of the extract reaction similar to the activity of extract inhibitory supernates preferentially produced from L5178Y-F9 cells. Exposure of the L5178Y-F9 to 0.25 M NaCl was associated with an increased production of inhibitory supernate and an increased sensitivity of the cell as an extract target. Pretreatment of inhibitor-containing supernatant or inhibitor-producing L5178Y-F9 cells with pronase or chondroitinase AC reduced the inhibitory activity of the resultant supernates, and L5178Y-F9 supernates treated with anti-chondroitin sulphate AC antibodies exhibited reduced inhibitory activity. These observations and the previously reported molecular weight heterogeneity and protease sensitivity of the inhibitor argue that chondroitin sulphate AC-containing proteoglycans released from the tumor cell surface may inhibit cytolysin activity, contributing to the preferential resistance of the L5178Y-F9 to rat NK granule extract cytolysis.
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PMID:RNK granule extract cytolysis: increased tumor susceptibility and release of proteochondroitin sulphate inhibitor in high NaCl. 206 59

The comparative accumulation of fluorescein Na2-salt (FINa) by the established cell lines of human tumors (cancer of the uterine body, urinary bladder, Wilms tumor, chorionepithelioma, melanoma, rhabdomyosarcoma, osteosarcoma) and human normal fibroblast cultures was obtained. The tumor cells of the different genesis is characterized by its own parameters of FINa accumulation. The most pronounced accumulation of dye has been noted for cells of cancer of the uterine body, the urinary bladder and chorionepithelioma. The normal cells accumulated FINa less considerably. Mechanism of the selective accumulation of dye by the tumor cells was discussed.
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PMID:[Accumulation of fluorescent dyes in tumor and normal cells of man]. 208 70

Skin tumor promotion induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) was inhibited by a concurrent and topical application of phthalic acid mono-n-butyl ester cupric salt (PAMBCu) in CD-1 mice initiated with 7,12-dimethylbenz[a]anthracene. PAMBCu inhibited TPA-caused epidermal ornithine decarboxylase (ODC) induction and ear edema formation, i.e. skin inflammation. However, neither PAMBCu nor superoxide dismutase (SOD) inhibited TPA-caused ODC induction in primary cultured mouse epidermal cells. 7-Bromomethylbenz[a]anthracene (BrMBA) is known to be a non-TPA type of tumor promoting agent. Epidermal ODC induction and inflammation caused by BrMBA were not inhibited by a concurrent application of PAMBCu. When mice were topically treated twice with PAMBCu, i.e. concurrently with and 7 h after BrMBA treatment, BrMBA-caused ODC induction was markedly suppressed. The same dose regimen of PAMBCu, however, failed to inhibit tumor promotion and inflammation caused by BrMBA. PAMBCu showed SOD-mimetic activity in superoxide generating systems, i.e. xanthine-xanthine oxidase reaction and TPA-stimulated polymorphonuclear leukocytes (PMN). Mono-n-butyl phthalate, which lacks SOD-mimetic activity, failed to inhibit TPA-caused ODC induction and skin inflammation. Therefore, inhibition by PAMBCu of TPA-caused tumor promotion, epidermal ODC induction and inflammation may be attributable to its SOD-mimetic activity. The results also support the contention that a superoxide anion of non-epidermal cell origin, such as PMN and macrophages, plays a role (probably some enhancing role) in in vivo ODC induction and tumor promotion caused by TPA. Failure of PAMBCu to inhibit BrMBA-caused tumor promotion suggests that superoxide anion generation is not involved in the tumor promoting action of this agent and that the anti-tumor promoting action of PAMBCu is dependent on the nature of the tumor promoting agents.
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PMID:Anti-tumor promoting action of phthalic acid mono-n-butyl ester cupric salt, a biomimetic superoxide dismutase. 211 May 12

The kinetics of phosphorylation of an integral membrane enzyme, Na+/K(+)-ATPase, by calcium- and phospholipid-dependent protein kinase C (PKC) were characterized in vitro. The phosphorylation by PKC occurred on the catalytic alpha-subunit of Na+/K(+)-ATPase in preparations of purified enzyme from dog kidney and duck salt-gland and in preparations of duck salt-gland microsomes. The phosphorylation required calcium (Ka approximately 1.0 microM) and was stimulated by tumor-promoting phorbol ester (12-O-tetradecanoylphorbol 13-acetate) in the presence of a low concentration of calcium (0.1 microM). PKC phosphorylation of Na+/K(+)-ATPase was rapid and plateaued within 30 min. The apparent Km of PKC for Na+/K(+)-ATPase as a substrate was 0.5 microM for dog kidney enzyme and 0.3 microM for duck salt-gland enzyme. Apparent substrate inhibition of PKC activity was observed at concentrations of purified salt-gland Na+/K(+)-ATPase greater than 1.0 microM. Phosphorylation of purified kidney and salt-gland Na+/K+ ATPases occurred at both serine and threonine residues. The 32P-phosphopeptide pattern on 15% sodium dodecyl sulfate-polyacrylamide gel electrophoresis after hydroxylamine cleavage of pure 32P-phosphorylated alpha subunit was the same for the two sources of enzyme, which suggests that the phosphorylation sites are similar. The results indicate that Na+/K(+)-ATPase may serve as a substrate for PKC phosphorylation in intact cells and that the Na+/K(+)-ATPase could be a useful in vitro model substrate for PKC interaction with integral membrane proteins.
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PMID:Kinetics of phosphorylation of Na+/K(+)-ATPase by protein kinase C. 215 96

Polyoma virus large tumor antigen (PyV T antigen) has been purified to near homogeneity by immunoaffinity column chromatography. We have detected DNA helicase and ATPase (nucleoside-5'-triphosphatase) activities in the purified PyV T antigen fraction and characterized these activities. The ATPase activity was stimulated about 2-fold by poly(dT), which was the most effective stimulator among the synthetic polynucleotides tested. Natural nucleic acids, such as calf thymus native and heat-denatured DNA, and single-stranded circular fd DNA were also effective, but the degree of stimulation was less than 1.5-fold. The basal and poly(dT)-stimulated ATPase activities showed similar preference for nucleoside 5'-triphosphates, requirement for divalent cations, and pH optima. The preference for nucleoside 5'-triphosphates was ATP, dATP greater than CTP, UTP much greater than GTP. The only difference observed between the two activities was salt sensitivity. The basal ATPase activity was resistant to KC1 up to 300 mM. In contrast, poly-(dT)-stimulated activity was reduced to the level of basal activity at 300 mM KC1. DNA helicase activity required divalent cations and was dependent on hydrolysis of ATP. The activity showed similar preference for nucleoside 5'-triphosphates, requirement for divalent cations, and pH optimum as the two ATPase activities, and the salt sensitivity of DNA helicase activity was similar to that of poly(dT)-stimulated ATPase activity. The helicase activity was inhibited competitively by the addition of single-stranded or double-stranded DNA, and a relatively high inhibitory activity was observed with poly [d(A-T)]. The PyV T antigen helicase was found to migrate in the 3' to 5' direction along the DNA strand to which the protein bound.
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PMID:DNA helicase and nucleoside-5'-triphosphatase activities of polyoma virus large tumor antigen. 216 Feb 69

We have recently presented biochemical evidence for collagen and gelatin degrading activities associated with plasma membranes of various human cancer cell lines. In this report we describe the localization of interstitial collagenase at the basal plasma membrane of the human pancreatic cancer cell line RWP-I, using immunofluorescence and ultrastructural immunogold labeling techniques. Collagenase was expressed on the extracellular face of the plasma membrane. Furthermore, the immunogold labeling was concentrated on the long, finger-like microvillous projections typically seen on the basal cell surface, while the short, brush-like projections characteristic of the apical cell surface were unlabeled. When the cytoplasmic face of the membrane was made accessible, the number of reactive sites increased markedly, indicating a high concentration of enzyme at the inner surface of the plasma membrane. When plasma membrane fractions of RWP-I cells were prepared by differential centrifugation, high salt washes virtually failed to extract collagenase activity from the membrane, while detergent extraction with n-octyl glucoside, a detergent used in the purification of integral membrane proteins, yielded soluble collagenase activity. When detergent extracted membrane fractions were passed over an anticollagenase immunoaffinity column, collagenase was specifically bound, as demonstrated by the TCA and TCB degradation of type I collagen by the bound material. Gelatinolytic activity did not bind to the column. Furthermore, immunoprecipitation of 125I-labeled detergent extracts of tumor membranes yielded a single Mr 55,000 band consistent with the zymogen form of the connective tissue collagenase. These morphological and biochemical findings suggest that collagenase is a tightly associated component of the basal plasma membrane, where it occupies a strategic location for directional proteolysis during cell migration and invasion.
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PMID:Localization of collagenase at the basal plasma membrane of a human pancreatic carcinoma cell line. 217 14

A rapid colorimetric microtiter assay was used in this study to analysis drug cytotoxicity. Through the reduction of tetrazolium salt, MTT [3-(4, 5-dimethyl-thiazol-2-yl) 2,5-diphenyl tetrazolium bromide], by living cells to form a blue formazan product. The level of MTT cleavage by viable cells of various origins was found to be in direct proportion to the number of cells (between 500-10,000 cells/well). By MTT methods, the growth profile and chemosensitivity of 4 human tumor cell lines (KB, Hep-2, HA22T, and CoLo205) to 4 anticancer drugs (adriamycin, 5-fluorouracil, 6-mercaptopurine and cyclophosphamide) were assessed. Results from this assay were compared with data assimilated simultaneously by dye exclusion and clonogenic assay. In general, good correlation was observed among the clonogenic, dye exclusion and MTT assays for continuous drug exposures, yet the MTT assay was more rapid in testing in vitro chemosensitivity against human tumor cell lines. The dye exclusion assay was the most sensitive, followed by the clonogenic and then the MTT assays. The ID50 values obtained from the MTT assay were approximately 3 to 5 times lower than those from the other two methods. Based on these studies, MTT assay appears to be a rapid, convenient, economical and reasonable tool in the initial-stage screening of large number of the in vitro anticancer drugs.
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PMID:Evaluation of a rapid tetrazolium-based colorimetric assay for selecting anticancer drugs. 217 28

Gastric cancer is a very typical cancer related to life styles, including nutrition and dietary conditions. Cigarette smoking has also been pointed out as an enhancing factor in gastric cancer development. Improvement of dietary conditions, regular dietary habits including lower salt, nitrite and nitrite intake and balanced nutritious food may be factors suppressing the incidence of gastric cancer. At the same time, advances in technology for early diagnosis and early surgical treatment have elevated the cure rate of gastric cancers. From both primary and secondary cancer prevention aspects, gastric cancer is now a conquerable disease.
Med Oncol Tumor Pharmacother 1990
PMID:Gastric carcinogenesis: diet as a causative factor. 223 42

The protein BM-90 was solubilized from the mouse Engelbreth-Holm-Swarm tumor with neutral buffers in molar yields lower (15-30%) than found for other basement membrane proteins (e.g. laminin, BM-40). The purified protein was shown to be rich in cysteine (5 mol%) and to change in SDS electrophoresis from an 84-kDa position to a 95-kDa one upon reduction. BM-90 was also shown to be a calcium-binding protein. The N-terminal sequence of BM-90, as well as those of several internal peptides, showed no identity with any known protein sequences, indicating that it is a new protein. Specific radioimmunoassays showed no or only minor cross-reactions with other known basement membrane proteins. Immunological assays demonstrated BM-90 to be present in neutral salt extracts from mouse heart and kidney, in serum (20-40 micrograms/ml) and in the medium of various cultured cells (0.1-1 microgram/ml). The protein in these samples was identical in size to BM-90 purified from the tumor, indicating that negligible degradation occurs during purification. An extracellular matrix localization of BM-90 was shown by immunofluorescence for Reichert's membrane, lens capsules and other basement membranes. Thus, BM-90 appears to be a novel basement membrane protein whose functions remain to be studied.
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PMID:Characterization of a novel calcium-binding 90-kDa glycoprotein (BM-90) shared by basement membranes and serum. 224 86

Ascite tumor cells EL-4 were incubated in conditions of energy starvation (Hanks salt solution with rothenone and without glucose) at 37 degrees C for 3 hours. Under these conditions, some structural cell damages appeared within the first hours: enlarging and flattening of the cells, blebbing, vacuolization of the cytoplasm, nuclear chromatin condensation. Later on, a share of cells with obvious damage decreased, whereas that of the cells stained with trypan blue (dead cells) much increased (up to 90% after a 3 hour incubation). The cellular ATP decreased abruptly (up to 10% of the control) during the first 10 minutes of starvation. Free Ca2+ concentration increased within 1 hour of incubation more than two-fold. The conditions promoting Ca2+ influx (ionophore A23187 + Ca2+ in medium) accelerated the damage and cell death. However, the increase in free Ca2+ concentration did not trigger any damage in the energy-starved cells, since in the Ca2(+)-depleted medium (no increase in free Ca2(+)-concentration) the development of damages was not prevented. The damage initiation was irreversible: the addition of glucose to cell suspensions after 0.5-1 hour of their incubation in energy-starved condition did not prevent the development of damage, while ATP content in these cells was much increased.
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PMID:[The relationship of damage to and death of ascitic tumor cells during starvation to the ATP and free calcium content in the cells]. 226 Feb 24


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