n(2)-n(2)-dimethylguanosine and Breast-Neoplasms

Evaluation of altered urinary nucleosides before and after tumor removal of breast cancer (BCa).. Targeted metabolite profiling of 14 urinary nucleosides was conducted with both pre- and post-operative female patients with BCa (n=150, age: 46.6+/-7.7 years), and female controls (n=150, age: 46.8+/-7.7 years) by liquid chromatography-tandem mass spectrometry coupled to on-line extraction.. Levels of modified nucleosides (5-hydroxymethyl-2'-deoxyuridine, P<0.001; 8-hydroxy-2'-deoxyguanosine, P<0.001; 1-methyladenosine, P<0.02; N(2),N(2)-dimethylguanosine, P<0.001) were significantly higher in pre-operative patients than in both normal controls and post-operative patients.. This approach could be used to further understand the pathogenesis of BCa as well as to evaluate the effects of medical treatment.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adenosine; Adult; Breast Neoplasms; Chromatography, Liquid; Deoxyguanosine; Female; Guanosine; Humans; Mastectomy; Middle Aged; Nucleosides; Oxidative Stress; Postoperative Period; Reactive Oxygen Species; Tandem Mass Spectrometry; Thymidine

Cancer, like other diseases accompanied by strong metabolic disorders, shows characteristic effects on cell turnover rate, activity of modifying enzymes and DNA/RNA modifications, resulting also in elevated amounts of excreted modified nucleosides. For a better understanding of the impaired RNA metabolism in breast cancer cells, we screened these metabolites in the cell culture supernatants of the breast cancer cell line MCF-7 and compared it to the human mammary epithelial cells MCF-10A. The nucleosides were isolated and analyzed via 2D-chromatographic techniques: In the first dimension by cis-diol specific boronate affinity extraction and subsequently by reversed phase chromatography coupled to an ion trap mass spectrometer.. Besides the determination of ribonucleosides, additional compounds with cis-diol structure, deriving from cross-linked biochemical pathways, like purine-, histidine- and polyamine metabolism were detected. In total, 36 metabolites were identified by comparison of fragmentation patterns and retention time. Relation to the internal standard isoguanosine yielded normalized area ratios for each identified compound and enabled a semi-quantitative metabolic signature of both analyzed cell lines.13 of the identified 26 modified ribonucleosides were elevated in the cell culture supernatants of MCF-7 cells, with 5-methyluridine, N2,N2,7-trimethylguanosine, N6-methyl-N6-threonylcarbamoyladenosine and 3-(3-aminocarboxypropyl)-uridine showing the most significant differences. 1-ribosylimidazole-4-acetic acid, a histamine metabolite, was solely found in the supernatants of MCF-10A cells, whereas 1-ribosyl-4-carboxamido-5-aminoimidazole and S-adenosylmethionine occurred only in supernatants of MCF-7 cells.. The obtained results are discussed against the background of pathological changes in cell metabolism, resulting in new perspectives for modified nucleosides and related metabolites as possible biomedical markers for breast carcinoma in vivo.

Topics: Adenosine; Aminoimidazole Carboxamide; Biomarkers, Tumor; Breast Neoplasms; Cell Line; Cell Line, Tumor; Epithelial Cells; Female; Guanosine; Humans; Imidazoles; Ions; Mammary Glands, Human; Metabolic Networks and Pathways; Ribonucleosides; Ribose; S-Adenosylmethionine; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Uridine

Urinary levels of the minor nucleosides, pseudouridine (psi),N2, N2-dimethylguanosine (m22G), and 1-methylinosine (m1I), were investigated in patients with breast carcinoma. Elevated levels of psi were observed in 27/131 (20.6%) patients with metastatic disease, 1/14 (7.1%) preoperative patients, and 1/28 (3.6%) postoperative N+ patients. Elevated levels of m22G and M1I were observed, respectively, in 46/131 (35.1%) and 274131 (20.6%) patients with metastatic disease, 3/14 (21.4%) and 3/14 preoperative patients, and 6/28 (21.4%) and 2/28 (7.1%) postoperative N+ patients. There was no correlation between nucleoside levels and involvement of specific organ sites with metastatic disease, nor with chemotherapy response rate or time to treatment failure. During the treatment of metastatic disease there was a tendency for elevated pretherapy psi levels to decrease with attainment of a response and, if the levels subsequently rose to be associated with treatment failure. However, increasing levels of m22G and 71I occurred with both response and disease progression. These results suggest that routine measurement of the level of the urinary nucleosides would be of limited value for following the disease course in patients with breast cancer.

Topics: Antineoplastic Agents; Breast Neoplasms; Drug Therapy, Combination; Female; Guanosine; Humans; Inosine; Lymphatic Metastasis; Neoplasm Metastasis; Pseudouridine; Uridine

A sensitive, rapid, and specific radioimmunoassay procedure was used to determine levels of N2,N2-dimethylguanosine and pseudouridine in sera of patients with acute leukemia and breast cancer. Elevated levels of both nucleosides were above standard deviations of the normal mean for patients in both disease categories.

Topics: Antibody Specificity; Breast Neoplasms; Guanosine; Humans; Leukemia; Methylation; Neoplasms; Pseudouridine; Radioimmunoassay; Uridine