title: SU11248 (sunitinib) directly inhibits the activity of mammalian 5'-AMP-activated protein kinase (AMPK).
abstract: AMPK has been termed the fuel sensor of mammalian cells because it directly responds to the depletion of the fuel molecule ATP. In previous work, we found that AMPK is strongly activated by tumor-like hypoxia and glucose deprivation, independently of the oxygen response system associated with HIF-1. We also observed high levels of AMPK activity in tumor cells in vivo, using different model tumors. These findings suggested the hypothesis that modulation of AMPK activity could have therapeutic value for the treatment of solid tumors. To investigate this hypothesis, we have been conducting a SAR study of potential small-molecule modulators of AMPK activity. Here we report that the chemotherapeutic drug SU11248 (sunitinib) is at least as potent an inhibitor of AMPK as compound C, which is a commonly used experimental direct inhibitor of the enzyme. We also provide a computational model of the binding pose of SU11248 to an AMPKα subunit, which suggests a structural basis for the affinity of the drug for the ATP site of the catalytic domain. The ability of SU11248 to inhibit AMPK has potential clinical significance--there may be populations of SU11248-treated patients in which AMPK activity is inhibited in normal as well as in tumor tissue.
authors.affiliation: SRI International, Menlo Park, CA, USA. keith.laderoute@sri.com
authors.forename: Keith R
authors.initials: KR
authors.lastname: Laderoute
authors.forename: Joy M
authors.initials: JM
authors.lastname: Calaoagan
authors.forename: Peter B
authors.initials: PB
authors.lastname: Madrid
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Klon
authors.forename: Paula J
authors.initials: PJ
authors.lastname: Ehrlich
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000037:antagonists & inhibitors* / Q000502:physiology*; D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D004622:Embryo, Mammalian / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D015151:Immunoblotting; D007211:Indoles / Q000494:pharmacology*; D051379:Mice; D018345:Mice, Knockout; D008958:Models, Molecular; D017346:Protein Serine-Threonine Kinases / Q000502:physiology; D011720:Pyrazoles / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology*; D000077210:Sunitinib
chemical_list: D020533:Angiogenesis Inhibitors; D007211:Indoles; D011720:Pyrazoles; D011743:Pyrimidines; D011758:Pyrroles; C516138:dorsomorphin; D017346:Protein Serine-Threonine Kinases; C491654:Stk11 protein, mouse; D055372:AMP-Activated Protein Kinases; D000077210:Sunitinib