Many cancer cells are characterized by high rate of glycolysis and reduced rate of aerobic respiration, whose mechanism is still elusive. Here we investigate the down-regulation of oxidative phosphorylation (OXPHOS) in K-ras transformed mouse fibroblasts as compared to a control counterpart. Transcriptional analysis showed different expression levels of several OXPHOS nuclear genes in the two cell lines. In particular, during the exponential growth phase most genes encoding proteins of Complex I were expressed at lower levels in transformed cells. Consistently, a significant decrease of Complex I content was found in transformed cells. Moreover, analysis of NAD-dependent respiration and ATP synthesis indicated a strong decrease of Complex I activity in the mitochondria from neoplastic cells, that was confirmed by direct assay of the enzyme redox activity. At variance, succinate-dependent respiration and ATP synthesis were not significantly affected. Taken together, our results provide the new insight that the reduction of respiration observed in K-ras transformed cells is specifically due to a Complex I activity decrease.

Baracca, A., Chiaradonna, F., Sgarbi, G., Solaini, G., Alberghina, L., Lenaz, G. (2009). Mitochondrial Complex I decrease is responsible for bioenergetic dysfunction in K-ras transformed cells. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS, 1797(2), 314-323.

Mitochondrial Complex I decrease is responsible for bioenergetic dysfunction in K-ras transformed cells

CHIARADONNA, FERDINANDO;ALBERGHINA, LILIA;
2009

Abstract

Many cancer cells are characterized by high rate of glycolysis and reduced rate of aerobic respiration, whose mechanism is still elusive. Here we investigate the down-regulation of oxidative phosphorylation (OXPHOS) in K-ras transformed mouse fibroblasts as compared to a control counterpart. Transcriptional analysis showed different expression levels of several OXPHOS nuclear genes in the two cell lines. In particular, during the exponential growth phase most genes encoding proteins of Complex I were expressed at lower levels in transformed cells. Consistently, a significant decrease of Complex I content was found in transformed cells. Moreover, analysis of NAD-dependent respiration and ATP synthesis indicated a strong decrease of Complex I activity in the mitochondria from neoplastic cells, that was confirmed by direct assay of the enzyme redox activity. At variance, succinate-dependent respiration and ATP synthesis were not significantly affected. Taken together, our results provide the new insight that the reduction of respiration observed in K-ras transformed cells is specifically due to a Complex I activity decrease.
Articolo in rivista - Articolo scientifico
oncogene, K-ras, trasformation, mitochondria dysfunction
English
18-nov-2009
1797
2
314
323
none
Baracca, A., Chiaradonna, F., Sgarbi, G., Solaini, G., Alberghina, L., Lenaz, G. (2009). Mitochondrial Complex I decrease is responsible for bioenergetic dysfunction in K-ras transformed cells. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS, 1797(2), 314-323.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/8384
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