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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2011-4-15
pubmed:abstractText
PDK1 activates AKT suggesting that PDK1 inhibition might suppress tumor development. However, while PDK1 has been investigated intensively as an oncology target, selective inhibitors suitable for in vivo studies have remained elusive. In this study we present the results of in vivo PDK1 inhibition through a universally applicable RNAi approach for functional drug target validation in oncogenic pathway contexts. This approach, which relies on doxycycline-inducible shRNA expression from the Rosa26 locus, is ideal for functional studies of genes like PDK1 where constitutive mouse models lead to strong developmental phenotypes or embryonic lethality. We achieved more than 90% PDK1 knockdown in vivo, a level sufficient to impact physiological functions resulting in hyperinsulinemia and hyperglycemia. This phenotype was reversible on PDK1 reexpression. Unexpectedly, long-term PDK1 knockdown revealed a lack of potent antitumor efficacy in 3 different mouse models of PTEN-deficient cancer. Thus, despite efficient PDK1 knockdown, inhibition of the PI3K pathway was marginal suggesting that PDK1 was not a rate limiting factor. Ex vivo analysis of pharmacological inhibitors revealed that AKT and mTOR inhibitors undergoing clinical development are more effective than PDK1 inhibitors at blocking activated PI3K pathway signaling. Taken together our findings weaken the widely held expectation that PDK1 represents an appealing oncology target.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1538-7445
pubmed:author
pubmed-author:AndersenJannik NJN, pubmed-author:AndradePaulaP, pubmed-author:AngagawMinilikM, pubmed-author:Blume-JensenPeterP, pubmed-author:BobkovaEkaterina VEV, pubmed-author:BronsonRoderick TRT, pubmed-author:ConnorYamiciaY, pubmed-author:Di BaccoAlessandraA, pubmed-author:DolinskiBrianB, pubmed-author:DraettaGiulioG, pubmed-author:Ellwood-YenKatharineK, pubmed-author:ErkulYusufY, pubmed-author:GarganoDianaD, pubmed-author:HurdMelissaM, pubmed-author:IzuMM, pubmed-author:KasibhatlaShailajaS, pubmed-author:KeilhackHeikeH, pubmed-author:KohlNancyN, pubmed-author:KrausManfredM, pubmed-author:KuniiKaikoK, pubmed-author:LecceseEricaE, pubmed-author:NagashimaKumikoK, pubmed-author:NorthrupAlanA, pubmed-author:O'HareErinE, pubmed-author:RichonVictoriaV, pubmed-author:ScottMartin LML, pubmed-author:ShinMyung KMK, pubmed-author:ShomerNirah HNH, pubmed-author:VogtThomas FTF
pubmed:copyrightInfo
©2011 AACR.
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
71
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3052-65
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
PDK1 attenuation fails to prevent tumor formation in PTEN-deficient transgenic mouse models.
pubmed:affiliation
Merck Research Laboratories, Harvard Medical School, Boston, Massachusetts, USA.
pubmed:publicationType
Journal Article