Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

From an extended series neuroblastoma cases evaluated for MYCN amplification (MNA) at the "G. Gaslini" Hospital 15 (4 with and 11 without NMA) underwent myeloablative therapy and bone marrow transplantation (MAT-ABMT). Such cases ranged in age at diagnosis from 13 months to 7 years and were followed up at least 8 months after MAT-ABMT. MNA was present in 2/10 cases dead for disease, in 0/1 cases alive with disease, and in 2/4 cases presently in complete clinical remission. This preliminary evidence would discourage to consider MNA as a marker capable of predicting the final outcome of patients with metastatic Nb.
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PMID:MYCN amplification does not affect survival of neuroblastoma patients treated with autologous bone marrow transplantation. 185 77

Adaptive changes occurring in C1300 murine neuroblastoma cell lines developed for resistance to nucleoside analogue inhibitors of S-adenosyl-L-homocysteine hydrolase (AdoHcyase, EC 3.3.1.1) were investigated. Two drug-resistant cell lines, rMNB-MDL-7-2 and rMNB-Deaz-7-2, were established from wild-type C1300 neuroblastoma cells (wMNB) following incubation with the AdoHcyase inhibitors (Z)-4',5'-didehydro-5'-deoxy-5'-fluoroadenosine (MDL 28,842) and 3-deazaneplanocin A, respectively. The nucleoside analogue concentration required to inhibit cellular proliferation by 50% (IC50) was 3.2 x 10(2) to 4.3 x 10(3) fold higher in the resistant cells when compared with the wMNB cell line. The proliferation rates of the resistant cell lines under in vitro or in vivo conditions were significantly lower than the wMNB cell line. In contrast to wMNB, both resistant cell lines had slower doubling times in tissue culture (22% longer) and smaller tumor weights (55% smaller) 14 days after implantation in A/J mice. No significant differences in AdoHcyase activity were noted between the resistant and wild-type cell lines. The resistant cell lines had concentrations of S-adenosyl-L-methionine that were five times higher and methionine adenosyltransferase (MAT, EC 2.5.1.6) activities that were two to four times greater than the wMNB phenotype. These data indicate that neuroblastoma tumor cell resistance to AdoHcyase inhibitors is associated with an adaptive increase in MAT activity. This cellular response facilitates methylation by elevating intracellular concentrations of the methyl donor S-adenosyl-L-methionine, thereby sustaining tumor cell viability in the presence of MDL 28,842 and 3-deazaneplanocin A.
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PMID:Resistance to inhibitors of S-adenosyl-L-homocysteine hydrolase in C1300 murine neuroblastoma tumor cells is associated with increased methionine adenosyltransferase activity. 886 60

The human neuroblastoma cell line SH-SY5Y was used to study the regulation of methionine adenosyltransferase (MAT II; E.C.2.5.1.6.) catalytic activity and transcript levels in cells of neuronal origin. The cells were exposed for 24 hr to a medium containing different concentrations of methionine (MAT substrate) as well as medium deficient of methionine. Furthermore, cells were treated with hydroxycobalamin, SAM, and the competitive MAT inhibitor cycloleucine. The MAT catalytic activity was inversely correlated to methionine concentrations, e.g. MAT Vmax increased 2-fold in cells grown in methionine-deficient medium as compared with cells cultured under standard conditions. Interestingly, MAT Km also increased from 9.04 +/- 0.44 to 12.08 +/- 0.83 in the methionine-deficient medium. Hydroxycobalamin caused an increase in activity at 40 microM while a decrease was observed at higher concentrations (100, 200, and 400 microM). Cycloleucine caused a significant inhibition of MAT catalytic activity, i.e. the inhibition was approximately 50% in the presence of 4 mM cycloleucine. The relevance of these results for the understanding of observations on MAT catalytic activity in brains of patients with Alzheimer's disease is discussed.
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PMID:Regulation of methionine adenosyltransferase catalytic activity and messenger RNA in SH-SY5Y human neuroblastoma cells. 951 67