Novel small molecule inhibitors of caspase-3 block cellular and biochemical features of apoptosis.
Caspase-3 is an intracellular cysteine protease, activated as part of the apoptotic response to cell injury. Its interest as a therapeutic target has led many to pursue the development of inhibitors. To date, only one series of nonpeptidic inhibitors have been described, and these have limited selectivity within the caspase family. Here we report the properties of a series of anilinoquinazolines (AQZs) as potent small molecule inhibitors of caspase-3. The AQZs inhibit human caspase-3 with Ki values in the 90 to 800 nM range. A subset of AQZs are equipotent against caspase-6, although most lack activity against this isoform and caspase-1, -2, -7, and -8. The AQZs inhibit endogenous caspase-3 activity toward a cell permeable, exogenously added substrate in staurosporine-treated SH-SY5Y cells. The AQZs reduce biochemical and cellular features of apoptosis that are thought to be a consequence of caspase-3 activation including DNA fragmentation, TUNEL staining, and the various morphological features that define the terminal stages of apoptotic cell death. Moreover, the AQZs also inhibit apoptosis induced by nerve growth factor withdrawal from differentiated PC12 cells. Thus, the AQZs represent a new and structurally novel class of inhibitors, some of which selectively inhibit caspase-3 and will thereby allow evaluation of the role of caspase-3 activity in various cellular models of apoptosis.
Scott
Clay W
CW
Departments of Lead Discovery, Neuroscience, and Chemistry, AstraZeneca Pharmaceuticals, Wilmington, Delaware 19810, USA. clay.scott@astrazeneca.com
Sobotka-Briner
Cindy
C
Wilkins
Deidre E
DE
Jacobs
Robert T
RT
Folmer
James J
JJ
Frazee
William J
WJ
Bhat
Ratan V
RV
Ghanekar
Smita V
SV
Aharony
David
D
D000814:Aniline Compounds / Q000138:chemical synthesis / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D053148:Caspase 3; D061945:Caspase Inhibitors; D002460:Cell Line; D004396:Coloring Agents; D053938:DNA Fragmentation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000494:pharmacology*; D005456:Fluorescent Dyes; D006801:Humans; D020287:In Situ Nick-End Labeling; D007700:Kinetics; D020932:Nerve Growth Factor / Q000494:pharmacology; D016716:PC12 Cells; D010641:Phenotype; D011799:Quinazolines / Q000138:chemical synthesis / Q000494:pharmacology*; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D019311:Staurosporine / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013552:Swine
D000814:Aniline Compounds; D061945:Caspase Inhibitors; D004396:Coloring Agents; D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D011799:Quinazolines; D011994:Recombinant Proteins; D020932:Nerve Growth Factor; C505407:CASP3 protein, human; C505410:Casp3 protein, rat; D053148:Caspase 3; D019311:Staurosporine