Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0035412 (rhabdomyosarcoma)
 6,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In studying the bioenergetics of living cells, the microfluorometric analysis of coenzyme (NAD(P)H) responses to microinjected respiratory and glycolytic substrates enables, in principle, a search for qualitative/quantitative differences in normal versus carcinogen-treated (short-term, long-term) and malignant cells. Responses are compared in L-cells, same adapted to hypertonic media (i.e. L255, L355) and highly malignant rhabdomyosarcoma (CCL 136) cells. The largest responses to respiratory substrate (malate, isocitrate) and the lowest responses to glycolytic substrate (glucose-6-P) are in the L255, 355 cells which exhibit structural rearrangement and dense packing of mitochondria possibly due to high energy requirement for ion pumping. The converse is observed in the CCl 136 where there is no lack of these organelles, but they could be functionally deficient, as suggested by a predominant response to glucose-6-P compared to malate. In the control L-cell, the malate and glucose-6-P responses are relatively well balanced. Upon addition of dimethylnitrosamine to L-cells, there is an initial acceleration in the rate of glucose-6-P-induced NAD(P) reduction (? NADPH requirement for dimethylnitrosamine metabolization), followed by an upsurge of the malate response. In L355 cells, addition of the carcinogens dimethylnitrosamine or ethionine is followed by a strong reductive response to malate, and minimal response to glucose-6-P. The dramatic intensification of the NAD(P)H response to malate in L355 cells pretreated with an ATP trap (ethionine) or an uncoupler (dinitrophenol) strongly points to a requirement for ATP depletion. Weaker enhancement of NAD(P)H response (preferentially after glucose-6-P) is observed in the CCL 136 upon treatment with ethionine. The findings indicate the need for further study on differences in respiratory/glycolytic pathways and efficiency of ATP cycle in malignant cells exhibiting graded differences of structural/functional specialization.
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PMID:The differential effects of dimethylnitrosamine and ethionine on mitochondrial and extramitochondrial dehydrogenases in single intact cells. 669 53

Sirtuins are NAD+ dependent deacetylases and/or ADP-ribosyl transferases active on histone and non-histone substrates. The first sirtuin was discovered as a transcriptional repressor of the mating-type-loci (Silent Information Regulator sir2) in the budding yeast, where it was shown to extend yeast lifespan. Seven mammalian sirtuins (SIRT1-7) have been now identified with distinct subcellular localization, enzymatic activities and substrates. These enzymes regulate cellular processes such as metabolism, cell survival, differentiation, DNA repair and they are implicated in the pathogenesis of solid tumors and leukemias. The purpose of the present study was to investigate the role of sirtuin expression, activity and inhibition in the survival of pediatric sarcoma cell lines.We have analyzed the expression of SIRT1 and SIRT2 in a series of pediatric sarcoma tumor cell lines and normal cells, and we have evaluated the activity of the sirtuin inhibitor and p53 activator tenovin-6 (Tv6) in synovial sarcoma and rhabdomyosarcoma cell lines. We show that SIRT1 is overexpressed in synovial sarcoma biopsies and cell lines in comparison with normal mesenchymal cells. Tv6 induced apoptosis as well as impaired autophagy flux. Using siRNA to knock down SIRT1 and SIRT2, we show that the expression of both proteins is crucial for the survival of rhabdomyosarcoma cells and that the loss of SIRT1 expression results in a decreased LC3II expression. Our results show that SIRT1 and SIRT2 expressions are crucial for the survival of synovial sarcomas and rhabdomyosarcomas, and demonstrate that the pharmacological inhibition of sirtuins impairs the autophagy process and induces tumor cell death.
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PMID:SIRT1 and SIRT2 inhibition impairs pediatric soft tissue sarcoma growth. 2534 Oct 37