| Autor: |
Telang Sucheta, Nelson Kristin K, Siow Deanna L, Yalcin Abdullah, Thornburg Joshua M, Imbert-Fernandez Yoannis, Klarer Alden C, Farghaly Hanan, Clem Brian F, Eaton John W, Chesney Jason |
| Jazyk: |
angličtina |
| Rok vydání: |
2012 |
| Předmět: |
|
| Zdroj: |
Molecular Cancer, Vol 11, Iss 1, p 60 (2012) |
| Druh dokumentu: |
article |
| ISSN: |
1476-4598 |
| DOI: |
10.1186/1476-4598-11-60 |
| Popis: |
Abstract Background Constitutive activation of Ras in immortalized bronchial epithelial cells increases electron transport chain activity, oxygen consumption and tricarboxylic acid cycling through unknown mechanisms. We hypothesized that members of the Ras family may stimulate respiration by enhancing the expression of the Vb regulatory subunit of cytochrome c oxidase (COX). Results We found that the introduction of activated H-RasV12 into immortalized human bronchial epithelial cells increased eIF4E-dependent COX Vb protein expression simultaneously with an increase in COX activity and oxygen consumption. In support of the regulation of COX Vb expression by the Ras family, we also found that selective siRNA-mediated inhibition of K-Ras expression in A549 lung adenocarcinoma cells reduced COX Vb protein expression, COX activity, oxygen consumption and the steady-state concentration of ATP. We postulated that COX Vb-mediated activation of COX activity may be required for the anchorage-independent growth of A549 cells as soft agar colonies or as lung xenografts. We transfected the A549 cells with COX Vb small interfering or shRNA and observed a significant reduction of their COX activity, oxygen consumption, ATP and ability to grow in soft agar and as poorly differentiated tumors in athymic mice. Conclusion Taken together, our findings indicate that the activation of Ras increases COX activity and mitochondrial respiration in part via up-regulation of COX Vb and that this regulatory subunit of COX may have utility as a Ras effector target for the development of anti-neoplastic agents. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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