Identification of small molecule inhibitors of phosphatidylinositol 3-kinase and autophagy
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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Identification of small molecule inhibitors of phosphatidylinositol 3-kinase and autophagy. / Farkas, Thomas; Daugaard, Mads; Jaattela, Marja.
I: Journal of Biological Chemistry, Bind 286, Nr. 45, 2011, s. 38904-12.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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TY - JOUR
T1 - Identification of small molecule inhibitors of phosphatidylinositol 3-kinase and autophagy
AU - Farkas, Thomas
AU - Daugaard, Mads
AU - Jaattela, Marja
PY - 2011
Y1 - 2011
N2 - Macroautophagy (hereafter autophagy) is a lysosomal catabolic pathway that controls cellular homeostasis and survival. It has recently emerged as an attractive target for the treatment of a variety of degenerative diseases and cancer. The targeting of autophagy has, however, been hampered by the lack of specific small molecule inhibitors. Thus, we screened two small molecule kinase inhibitor libraries for inhibitors of rapamycin-induced autophagic flux. The three most potent inhibitors identified conferred profound inhibition of autophagic flux by inhibiting the formation of autophagosomes. Notably, the autophagy inhibitory effects of all three compounds were independent of their established kinase targets, i.e. ataxia telangiectasia mutated for KU55933, protein kinase C for Gö6976, and Janus kinase 3 for Jak3 inhibitor VI. Instead, we identified phosphatidylinositol 3-kinase (PtdIns3K) as a direct target of KU55933 and Gö6976. Importantly, and in contrast to the currently available inhibitors of autophagosome formation (e.g. 3-methyladenine), none of the three compounds inhibited the cell survival promoting class I phosphoinositide 3-kinase-Akt signaling at the concentrations required for effective autophagy inhibition. Accordingly, they proved to be valuable tools for investigations of autophagy-associated cell death and survival. Employing KU55399, we demonstrated that autophagy protects amino acid-starved cells against both apoptosis and necroptosis. Taken together, our data introduce new possibilities for the experimental study of autophagy and can form a basis for the development of clinically relevant autophagy inhibitors.
AB - Macroautophagy (hereafter autophagy) is a lysosomal catabolic pathway that controls cellular homeostasis and survival. It has recently emerged as an attractive target for the treatment of a variety of degenerative diseases and cancer. The targeting of autophagy has, however, been hampered by the lack of specific small molecule inhibitors. Thus, we screened two small molecule kinase inhibitor libraries for inhibitors of rapamycin-induced autophagic flux. The three most potent inhibitors identified conferred profound inhibition of autophagic flux by inhibiting the formation of autophagosomes. Notably, the autophagy inhibitory effects of all three compounds were independent of their established kinase targets, i.e. ataxia telangiectasia mutated for KU55933, protein kinase C for Gö6976, and Janus kinase 3 for Jak3 inhibitor VI. Instead, we identified phosphatidylinositol 3-kinase (PtdIns3K) as a direct target of KU55933 and Gö6976. Importantly, and in contrast to the currently available inhibitors of autophagosome formation (e.g. 3-methyladenine), none of the three compounds inhibited the cell survival promoting class I phosphoinositide 3-kinase-Akt signaling at the concentrations required for effective autophagy inhibition. Accordingly, they proved to be valuable tools for investigations of autophagy-associated cell death and survival. Employing KU55399, we demonstrated that autophagy protects amino acid-starved cells against both apoptosis and necroptosis. Taken together, our data introduce new possibilities for the experimental study of autophagy and can form a basis for the development of clinically relevant autophagy inhibitors.
KW - Autophagy
KW - Carbazoles
KW - Cell Line, Tumor
KW - Enzyme Inhibitors
KW - Female
KW - Humans
KW - Morpholines
KW - Phosphatidylinositol 3-Kinases
KW - Proto-Oncogene Proteins c-akt
KW - Pyrones
KW - Signal Transduction
U2 - 10.1074/jbc.M111.269134
DO - 10.1074/jbc.M111.269134
M3 - Journal article
C2 - 21930714
VL - 286
SP - 38904
EP - 38912
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 45
ER -
ID: 38488596