Efficient Activation of Apoptotic Signaling during Mitotic Arrest with AK301.
Mitotic inhibitors are widely utilized chemotherapeutic agents that take advantage of mitotic defects in cancer cells. We have identified a novel class of piperazine-based mitotic inhibitors, of which AK301 is the most potent derivative identified to date (EC50 < 200 nM). Colon cancer cells arrested in mitosis with AK301 readily underwent a p53-dependent apoptosis following compound withdrawal and arrest release. This apoptotic response was significantly higher for AK301 than for other mitotic inhibitors tested (colchicine, vincristine, and BI 2536). AK301-treated cells exhibited a robust mitosis-associated DNA damage response, including ATM activation, γH2AX phosphorylation and p53 stabilization. The association between mitotic signaling and the DNA damage response was supported by the finding that Aurora B inhibition reduced the level of γH2AX staining. Confocal imaging of AK301-treated cells revealed multiple γ-tubulin microtubule organizing centers attached to microtubules, but with limited centrosome migration, raising the possibility that aberrant microtubule pulling may underlie DNA breakage. AK301 selectively targeted APC-mutant colonocytes and promoted TNF-induced apoptosis in p53-mutant colon cancer cells. Our findings indicate that AK301 induces a mitotic arrest state with a highly active DNA damage response. Together with a reversible arrest state, AK301 is a potent promoter of a mitosis-to-apoptosis transition that can target cancer cells with mitotic defects.
Department of Molecular and Cell Biology, University of Connecticut, 91 N Eagleville Rd, Storrs, Connecticut, United States of America.
Avijeet
A
Chopra
Department of Molecular and Cell Biology, University of Connecticut, 91 N Eagleville Rd, Storrs, Connecticut, United States of America.
Michael J
MJ
Bond
Department of Molecular and Cell Biology, University of Connecticut, 91 N Eagleville Rd, Storrs, Connecticut, United States of America.
Marina
M
Bleiler
Department of Molecular and Cell Biology, University of Connecticut, 91 N Eagleville Rd, Storrs, Connecticut, United States of America.
Michelle
M
Yeagley
School of Pharmacy, University of Connecticut, 69 N Eagleville Rd, Storrs, Connecticut, United States of America.
Dennis
D
Wright
Department of Molecular and Cell Biology, University of Connecticut, 91 N Eagleville Rd, Storrs, Connecticut, United States of America.
Charles
C
Giardina
D025601:Adenomatous Polyposis Coli Protein / Q000235:genetics; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D064007:Ataxia Telangiectasia Mutated Proteins / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D059447:Cell Cycle Checkpoints / Q000187:drug effects*; D003106:Colon / Q000166:cytology; D053960:DNA Breaks / Q000187:drug effects; D045325:HCT116 Cells; D019073:HT29 Cells; D006801:Humans; D051379:Mice; D008938:Mitosis / Q000187:drug effects*; D009154:Mutation; D010879:Piperazines / Q000494:pharmacology*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism
C587628:(4-(3-chlorophenyl)piperazin-1-yl)(2-ethoxyphenyl)methanone; C555337:APC protein, human; D025601:Adenomatous Polyposis Coli Protein; D010879:Piperazines; D016159:Tumor Suppressor Protein p53; D064007:Ataxia Telangiectasia Mutated Proteins; D053148:Caspase 3