Mertz Biro, Ann Christine. Class III phosphoinositide 3-kinase in melanoma. 2011, PhD Thesis, University of Basel, Faculty of Science.
Official URL: http://edoc.unibas.ch/diss/DissB_9562
In this work, we investigated the role of class III PI3K by two different methods, a pharmacological and a genetic approach. We started with natural compound screenings on hVps34 in genetically modified yeast systems. The pure fraction of Citrus medica extracts giving best results turned out to be limettin. Limettin inhibited hVps34 in both our in vivo yeast system and in in vitro kinase assays using the immunoprecipitated enzyme from HEK293 cells. Our candidate inhibitor seemed very specific for the human isoform, but still required quite high concentrations in the assays performed. Further chemical designing and eventual fitting to the hVps34 ATP binding pocket would be necessary to render this molecule into one of the first specific class III PI3K inhibitors.
In addition to pharmacological approaches, class III PI3K state-of-the-art genetic knockdown experiments were done in melanoma cell lines in order to characterize this isoform’s role in melanoma more specifically. Vps34 is not essential in yeast, but leads to serious temperature sensitivity phenotypes. In one melanoma cell line (A375) tested, knockdown had similar as but milder effects than known in other cancer types. Two others though (A2058 and 1205lu), did not tolerate the longterm loss of class III PI3K. We suppose that the importance of hVps34 depends on the genetic background of cell types. Further studies are required to define precisely which effectors determine the intolerance described i.e. which melanoma types could be targeted by inhibition of class III PI3K.
|Advisors:||Wymann, Matthias Paul|
|Committee Members:||Spiess, Martin|
|Faculties and Departments:||03 Faculty of Medicine > Departement Biomedizin > Division of Biochemistry and Genetics > Cancer- and Immunobiology (Wymann)|
|Bibsysno:||Link to catalogue|
|Number of Pages:||147 S.|
|Last Modified:||30 Jun 2016 10:42|
|Deposited On:||21 Sep 2011 11:46|
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