title: Activation of a novel ataxia-telangiectasia mutated and Rad3 related/checkpoint kinase 1-dependent prometaphase checkpoint in cancer cells by diallyl trisulfide, a promising cancer chemopreventive constituent of processed garlic.
abstract: Diallyl trisulfide (DATS), a cancer chemopreventive constituent of garlic, inhibits growth of cancer cells by interfering with cell cycle progression, but the mechanism is not fully understood. Here, we show the existence of a novel ataxia-telangiectasia mutated and Rad3 related (ATR)/checkpoint kinase 1 (Chk1)-dependent checkpoint partially responsible for DATS-mediated prometaphase arrest in cancer cells, which is different from the recently described gamma irradiation-induced mitotic exit checkpoint. The PC-3 human prostate cancer cells synchronized in prometaphase by nocodazole treatment and released to DATS-containing medium remained arrested in prometaphase, whereas the cells released to normal medium exited mitosis and resumed cell cycle. The mitotic arrest was maintained even after 4 h of culture of DATS-treated cells (4-h treatment) in drug-free medium. The DATS-arrested mitotic cells exhibited accumulation of anaphase-promoting complex/cyclosome (APC/C) substrates cyclin A and cyclin B1 and hyperphosphorylation of securin, which was accompanied by increased phosphorylation of the APC/C regulatory subunits Cdc20 and Cdh1. The DATS-mediated accumulation of cyclin B1 and hyperphosphorylation of securin, Cdc20, and Cdh1 were partially but markedly attenuated by knockdown of Chk1 or ATR protein. The U2OS osteosarcoma cells expressing doxycycline-inducible kinase dead ATR were significantly more resistant not only to DATS-mediated prometaphase arrest but also to the accumulation of cyclin B1 and hyperphosphorylation of securin, Cdc20, and Cdh1 compared with cells expressing wild-type ATR. However, securin protein knockdown failed to rescue cells from DATS-induced prometaphase arrest. In conclusion, the present study describes a novel signaling pathway involving ATR/Chk1 in the regulation of DATS-induced prometaphase arrest.
authors.affiliation: Department of Pharmacology, University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
authors.forename: Anna
authors.initials: A
authors.lastname: Herman-Antosiewicz
authors.forename: Silvia D
authors.initials: SD
authors.lastname: Stan
authors.forename: Eun-Ryeong
authors.initials: ER
authors.lastname: Hahm
authors.forename: Dong
authors.initials: D
authors.lastname: Xiao
authors.forename: Shivendra V
authors.initials: SV
authors.lastname: Singh
mesh_terms: D000498:Allyl Compounds / Q000494:pharmacology / Q000627:therapeutic use*; D064173:Anaphase-Promoting Complex-Cyclosome; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use; D064007:Ataxia Telangiectasia Mutated Proteins; D064199:Cdc20 Proteins; D018797:Cell Cycle Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor; D000071877:Checkpoint Kinase 1; D018890:Chemoprevention; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D005737:Garlic / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D008954:Models, Biological; D009363:Neoplasm Proteins / Q000378:metabolism; D009369:Neoplasms / Q000188:drug therapy* / Q000517:prevention & control*; D010766:Phosphorylation / Q000187:drug effects; D049468:Prometaphase / Q000187:drug effects*; D011494:Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D064249:Securin; D013440:Sulfides / Q000494:pharmacology / Q000627:therapeutic use*; D013997:Time Factors; D043743:Ubiquitin-Protein Ligase Complexes / Q000378:metabolism
chemical_list: D000498:Allyl Compounds; D000970:Antineoplastic Agents; D064199:Cdc20 Proteins; D018797:Cell Cycle Proteins; D009363:Neoplasm Proteins; D064249:Securin; D013440:Sulfides; C578002:pituitary tumor-transforming protein 1, human; C042577:diallyl trisulfide; C577488:CDC20 protein, human; D043743:Ubiquitin-Protein Ligase Complexes; D064173:Anaphase-Promoting Complex-Cyclosome; D011494:Protein Kinases; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1; D017346:Protein Serine-Threonine Kinases