Carretero, J. and Medina, P.P. and Blanco, R. and Smit, L. and Tang, M. and Roncador, G. and Maestre, L. and Conde, E. and Lopez-Rios, F. and Clevers, J.C. and Sanchez-Cespedes, M. (2006) Dysfunctional AMPK activity, signalling through mTOR and survival in response to energetic stress in LKB1-deficient lung cancer. Oncogene advance online publication. ISSN 09509232. doi:10.1038/sj.onc.1209951.
Full text not available from this repository.
LKB1, mutated in Peutz-Jeghers and in sporadic lung tumours, phosphorylates a group of protein kinases named AMP-activated protein kinase (AMPK)-related kinases. Among them is included the AMPK, a sensor of cellular energy status. To investigate the relevance of LKB1 in lung carcinogenesis, we study several lung cancer cells with and without LKB1-inactivating mutations. We report that LKB1-mutant cells are deficient for AMPK activity and refractory to mTOR inhibition upon glucose depletion but not growth-factor deprivation. The requirement for wild-type LKB1 to properly activate AMPK is further demonstrated in genetically modified cancer cells. In addition, LKB1-deficient lung primary tumours had diminished AMPK activity, assessed by complete absence or low level o phosphorylation of its critical substrate, acetyl-CoA carboxylase. We also demonstrate that LKB1 wild-type cells are more resistant to cell death upon glucose withdrawal than their mutant counterparts. Finally, modulation of AMPK activity did not affect PI3K/AKT signalling, an advantage for the potential use of AMPK as a target for cancer therapy in LKB1 wild-type tumours. Thus, sustained abrogation of cell energetic checkpoint control, through alterations at key genes, appear to be an obligatory step in the development of some lung tumours.
|Deposited On:||13 Feb 2009 17:14|
|Last Modified:||10 Dec 2009 13:14|
Repository Staff Only: item control page