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Query: UNIPROT:Q9UMR3 (NMR)
 150,598 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

31P and 13C NMR spectroscopy of lipid extracts of T47D human breast cancer spheroids and the use of 13C-labeled lipid precursors [3-13C]serine,[1,2-13C]ethanolamine, and [1,2-13C]choline enabled us to determine the rate of 13C incorporation into the major phospholipids and to show that the synthesis of phosphatidylethanolamine in T47D cells is via both the CDP-ethanolamine pathway and serine decarboxylation, with the extent of each depending on the concentration of ethanolamine in the medium. In the presence of low ethanolamine (3.4 microM), both pathways contribute in equal proportions, while in the presence of high ethanolamine, the CDP-ethanolamine pathway predominates.
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PMID:The application of 13C NMR to the characterization of phospholipid metabolism in cells. 131 37

31P- and 13C-NMR were used to determine the kinetics of choline and ethanolamine incorporation in T47D clone 11 human breast cancer cells grown as large (300 microns) spheroids. Spheroids were perfused inside the spectrometer with 1,2-13C-labeled choline or ethanolamine (0.028 mM) and the buildup of labeled phosphorylcholine (PC) or phosphorylethanolamine (PE) was monitored. To analyze the NMR kinetic data, it was assumed that each signal represents a weighted average of signal from the proliferating and non-proliferating compartments of the large spheroid. The average ATP pool size was 4 +/- 1 fmol/cell compared to 8 +/- 1 fmol/cell in small (150 microns) proliferating spheroids (P less than 0.0002). The average PC pool size at steady state was reduced to 11 +/- 6 fmol/cell compared to 22 +/- 8 (P less than 0.007). This could be correlated with an overall reduction of choline uptake in the non-proliferating spheroid fraction. The rate of the enzyme choline kinase was 0.3 fmol/(cell h) compared to 1.0 fmol/(cell h) (P less than 0.0001) for proliferating cells. The rate constant of CTP:phosphocholine cytidyltransferase (0.05 h-1) was not significantly altered, but the rate of the enzyme was reduced from 1.3 to 0.2-0.5 fmol/(cell h). The pool size of PE in medium containing serum ethanolamine (1.7 microM) was approximately the same (15 fmol/cell) in small and large spheroids. In the presence of high ethanolamine (0.028 mM) the average PE level decreased slightly (11 fmol/cell) and the rate of the enzyme ethanolamine kinase in the non-proliferating fraction was 0.7 fmol/(cell h) versus 1.0 fmol/(cell h) in the proliferating cells (P less than 0.07). The rate constant of CTP:phosphoethanolamine cytidyltransferase (0.07 h-1) was not significantly altered but the corresponding reaction rate was reduced from 1.4 to 0.2-0.8 fmol/(cell h). The kinetics of choline incorporation did not alter in the presence of 0.028 mM ethanolamine.
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PMID:Lipid metabolism in large T47D human breast cancer spheroids: 31P- and 13C-NMR studies of choline and ethanolamine uptake. 154 82

31P and 13C-NMR were used to determine the kinetics of choline and ethanolamine incorporation in T47D clone 11 human breast cancer cells grown as small (150 microns) spheroids. Spheroids were perfused inside the spectrometer with 1,2-13C-labeled choline or 1,2-13C-labeled ethanolamine (0.028 mM) and the buildup of labeled phosphoryl-choline (PC) or phosphorylethanolamine (PE) was monitored. Alternatively the PC and GPC pools were prelabeled with 13C and the reduction of label was monitored. 31P spectra were recorded from which the overall energetic status as well as total pool sizes could be determined. The ATP content was 8 +/- 1 fmol/cell, and the total PC and PE pool sizes were 16 and 14 fmol/cell, respectively. PC either increased by 50% over 24 h or remained constant, while PE remained constant in medium without added ethanolamine but increased 2-fold within 30 h in medium containing ethanolamine, indicating a dependence on precursor concentration in the medium. The 31P and 13C data yielded similar kinetic results: the rate of the enzymes phosphocholine kinase and phosphoethanolamine kinase were both on the order of 1.0 fmol/cell per h, and the rate constants for CTP:phosphocholine cytidyltransferase and CTP:phosphoethanolamine kinase were 0.06 h-1 for both enzymes. The kinetics of choline incorporation did not alter in the presence of 0.028 mM ethanolamine indicating that they have non-competing pathways.
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PMID:Lipid metabolism in T47D human breast cancer cells: 31P and 13C-NMR studies of choline and ethanolamine uptake. 165 90

The effects of 17 beta-estradiol, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and their combination on the metabolism of [1-13C] glucose were determined in cell suspensions of wild-type MCF-7 human breast cancer cells, by 13C NMR spectroscopy. Preliminary studies showed that, during the 7-hr duration of the NMR experiment, the cells maintained their viability and their aryl hydrocarbon responsiveness. Lactate was the major glucose metabolite detected in these studies, and the rate of lactate formation in the untreated (control) and 17 beta-estradiol (10(-9) M)-treated cells was 60 and 86 fmol/cell/hr, respectively; this represented a 40% increase in lactate formation in the cells treated with 17 beta-estradiol; comparable results were observed for the percentage of glucose converted into lactate. In contrast, TCDD (10(-9) M) did not significantly alter the rate of glucose metabolism or lactate formation. Co-treatment of the cells with 17 beta-estradiol (10(-9) M) plus TCDD (10(-8) to 10(-10) M) showed that TCDD completely inhibited the 17 beta-estradiol-induced metabolism of [13C] glucose to lactate in MCF-7 cells. In contrast, 2,8-dichlorodibenzo-p-dioxin (10(-8) M), a weak aryl hydrocarbon receptor agonist, did not inhibit estrogen-induced glucose-to-lactate metabolism in MCF-7 cells. In addition, it was shown that TCDD caused a significant decrease in 17 beta-estradiol-induced lactate formation within 1 hr after treatment, whereas the induction of monooxygenase activity was not observed until 3 hr after exposure of the cells to TCDD. These data indicate that TCDD-induced 17 beta-estradiol metabolism is not related to the decrease in the rate of conversion of glucose to lactate. These results further define the antiestrogenic responses elicited by TCDD and show that 13C NMR spectroscopy provides a unique method for measuring, in real time, the effects of TCDD on specific metabolic pathways.
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PMID:Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on 17 beta-estradiol-induced glucose metabolism in MCF-7 human breast cancer cells: 13C nuclear magnetic resonance spectroscopy studies. 175 38

Nuclear magnetic resonance spectroscopy was performed on breast cancer cell lines MCF-7, MDA-MB231 and T47D. Proton spectra showed discrepancies of lipid quantity in the different lines. The high resolution lines of lipids were not as intense in the membrane preparations. These results show the potential of NMR spectroscopy to study the involvement of membrane lipids in proliferation, metastasis or drug resistance process.
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PMID:[Lipid profiles of breast cancer cell lines: proton nuclear magnetic resonance spectroscopy]. 190 Jul 30

The composite methylene (chemical shift range 1.2-1.4 ppm) and methyl (0.8-0.9 ppm) resonances of the 1H NMR spectrum were analyzed in plasma samples from breast tumor patients, pregnant women, and healthy subjects. Using a 500 MHz NMR instrument operating at 25 degrees C, the peaks were analyzed for line width at half height and then averaged. A statistically significant difference (p less than 0.001) was found between the average (mean +/- SD) line width in the plasma samples from the 30 patients with metastatic breast cancer (34.1 +/- 5.0 Hz) and the controls matched for age and sex (38.7 +/- 4.4 Hz). In the 16 patients with localized breast cancer and the 16 with regional spread, the average line width was not different from that of matched controls. In 21 patients with benign tumor in the breast, the average line width was not different from that of matched controls. A difference in the average line width was found between 31 pregnant women in the third trimester (32.5 +/- 3.4 Hz) and their controls matched for age and sex (42.7 +/- 4.6 Hz) (p less than 0.001). The average line width was lower in the late (31.5 +/- 3.3) than in the early (34.5 +/- 2.5 Hz) part of the third trimester (p = 0.022). In 54 healthy male and 130 healthy female controls, line widths declined gradually with increasing age by decades, except in the fifth decade for the men and the sixth decade for the women.(ABSTRACT TRUNCATED AT 250 WORDS)
NMR Biomed 1991 Jun
PMID:Proton nuclear magnetic resonance spectroscopy measurements of methylene and methyl line widths in plasma: significant variations with extent of breast cancer, duration of pregnancy and aging. 191 Nov 2

We have previously described the application of water-suppressed proton nuclear magnetic resonance (H-1 NMR) spectroscopy of plasma for detection of malignancy. Subsequently, hypertriglyceridemia has been identified as a source of false positive results. We now describe a confirmatory, adjunctive technique--analysis of the carbon-13 (C-13) NMR spectrum of plasma--which also identifies the presence of malignancy but is not sensitive to the plasma triglyceride level. Blinded plasma samples from 480 normal donors and 208 patients scheduled for breast biopsy were analyzed by water-suppressed H-1 and C-13 NMR spectroscopy. Triglyceride levels were also measured. Among the normal donors, there were 38 individuals with hypertriglyceridemia of whom 18 had results consistent with malignancy by H-1 NMR spectroscopy. However, the C-13 technique reduced the apparent H-1 false positive rate from 7.0% to 0.6%. Similarly, in the breast biopsy cohort, C-13 reduced the false positive rate from 2.8% to 0.9%. Furthermore, the accuracy of the combined H-1/C-13 test in this blinded study was greater than 96% in 208 patients studied.
Breast Cancer Res Treat 1991 May
PMID:C-13 NMR spectroscopy of plasma reduces interference of hypertriglyceridemia in the H-1 NMR detection of malignancy. Application in patients with breast lesions. 191 13

A method is outlined that completely separates intracellular and extracellular information in NMR spectra of perfused cells. The technique uses diffusion weighting to exploit differences in motional properties between intra- and extracellular constituents. This allows monitoring of intracellular metabolism, and of transport of small drugs and nutrients through the cell membrane, under controlled physiological conditions. As a first example, proton spectra of drug-resistant MCF-7 human breast cancer cells are studied, and uptake of phenylalanine is monitored.
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PMID:Complete separation of intracellular and extracellular information in NMR spectra of perfused cells by diffusion-weighted spectroscopy. 201 44

22-Hydroxytingenone was reisolated from a new source, Glyptopetalum sclerocarpum M. Laws and, for the first time, its unambiguous 13C-NMR assignments were accomplished through the use of APT, HETCOR, and selective INEPT spectroscopy. Intense, but nonspecific cytotoxic activity was observed when this substance was evaluated with a battery of cell lines comprised of the P-388 lymphocytic leukemia, KB carcinoma of the nasopharynx, and a number of human cancer cell types, i.e. HT-1080 fibrosarcoma, LU-1 lung cancer, COL-2 colon cancer, MEL-2 melanoma, and BC-1 breast cancer.
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PMID:Spectral assignment and cytotoxicity of 22-hydroxytingenone from Glyptopetalum sclerocarpum. 223 93

Metabolism of 4-hydroxytamoxifen by hepatocytes isolated from rats administered with phenobarbital and examination by TLC of the components not extractable into ethyl acetate revealed 4-hydroxytamoxifen beta-glucuronide; its identity was confirmed by comparison of its 1H NMR spectrum with that of synthetic material. This conjugate was also formed on metabolism of tamoxifen. It bound to cytosolic oestrogen receptors with only one thousandth the affinity of 4-hydroxytamoxifen and gave a correspondingly very weak inhibition of growth of the MCF-7 human breast cancer cell line. Therefore, in contrast to reported observations on the 3-glucuronide of oestradiol, the MCF-7 cells were unable to hydrolyse 4-hydroxytamoxifen glucuronide and on this evidence, formation of this metabolite is solely a deactivation pathway.
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PMID:Metabolism of tamoxifen by isolated rat hepatocytes. Identification of the glucuronide of 4-hydroxytamoxifen. 233 45


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