title: Pharmacological targeting the ATR-CHK1-WEE1 axis involves balancing cell growth stimulation and apoptosis.
abstract: The ATR-CHK1-WEE1 kinase cascade's functions in the DNA damage checkpoints are well established. Moreover, its roles in the unperturbed cell cycle are also increasingly being recognized. In this connection, a number of small-molecule inhibitors of ATR, CHK1, and WEE1 are being evaluated in clinical trials. Understanding precisely how cells respond to different concentrations of inhibitors is therefore of paramount importance and has broad clinical implications. Here we present evidence that in the absence of DNA damage, pharmacological inactivation of ATR was less effective in inducing mitotic catastrophe than inhibition of WEE1 and CHK1. Small-molecule inhibitors of CHK1 (AZD7762) or WEE1 (MK-1775) induced mitotic catastrophe, as characterized by dephosphorylation of CDK1(Tyr15), phosphorylation of histone H39(Ser10), and apoptosis. Unexpectedly, partial inhibition of WEE1 and CHK1 had the opposite effect of accelerating the cell cycle without inducing apoptosis, thereby increasing the overall cell proliferation. This was also corroborated by the finding that cell proliferation was enhanced by kinase-inactive versions of WEE1. We demonstrated that these potential limitations of the inhibitors could be overcome by targeting more than one components of the ATR-CHK1-WEE1 simultaneously. These observations reveal insights into the complex responses to pharmacological inactivation of the ATR-CHK1-WEE1 axis.
authors.affiliation: Division of Life Science, Center for Cancer Research, and State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
authors.forename: Joyce P Y
authors.initials: JP
authors.lastname: Mak
authors.affiliation: Division of Life Science, Center for Cancer Research, and State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
authors.forename: Wing Yu
authors.initials: WY
authors.lastname: Man
authors.affiliation: Division of Life Science, Center for Cancer Research, and State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
authors.forename: Hoi Tang
authors.initials: HT
authors.lastname: Ma
authors.affiliation: Division of Life Science, Center for Cancer Research, and State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
authors.forename: Randy Y C
authors.initials: RY
authors.lastname: Poon
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D064007:Ataxia Telangiectasia Mutated Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D002453:Cell Cycle / Q000187:drug effects; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D000071877:Checkpoint Kinase 1; D005434:Flow Cytometry; D006801:Humans; D007124:Immunoenzyme Techniques; D008175:Lung Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D008938:Mitosis / Q000187:drug effects; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D011494:Protein Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D011720:Pyrazoles / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology*; D011744:Pyrimidinones; D013876:Thiophenes / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D014508:Urea / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: C532363:3-(carbamoylamino)-5-(3-fluorophenyl)-N-(3-piperidyl)thiophene-2-carboxamide; D018797:Cell Cycle Proteins; D009687:Nuclear Proteins; D011720:Pyrazoles; D011743:Pyrimidines; D011744:Pyrimidinones; D013876:Thiophenes; D014508:Urea; D011494:Protein Kinases; D011505:Protein-Tyrosine Kinases; C499349:WEE1 protein, human; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1; C549567:adavosertib