title: NEDD8-targeting drug MLN4924 elicits DNA rereplication by stabilizing Cdt1 in S phase, triggering checkpoint activation, apoptosis, and senescence in cancer cells.
abstract: MLN4924 is a first-in-class experimental cancer drug that inhibits the NEDD8-activating enzyme, thereby inhibiting cullin-RING E3 ubiquitin ligases and stabilizing many cullin substrates. The mechanism by which MLN4924 inhibits cancer cell proliferation has not been defined, although it is accompanied by DNA rereplication and attendant DNA damage. Here we show that stabilization of the DNA replication factor Cdt1, a substrate of cullins 1 and 4, is critical for MLN4924 to trigger DNA rereplication and inhibit cell proliferation. Even only 1 hour of exposure to MLN4924, which was sufficient to elevate Cdt1 for 4-5 hours, was found to be sufficient to induce DNA rereplication and to activate apoptosis and senescence pathways. Cells in S phase were most susceptible, suggesting that MLN4924 will be most toxic on highly proliferating cancers. Although MLN4924-induced cell senescence seems to be dependent on induction of p53 and its downstream effector p21(Waf1), we found that p53(-/-) and p21(-/-) cells were even more susceptible than wild-type cells to MLN4924. Our results suggested that apoptosis, not senescence, might be more important for the antiproliferative effect of MLN4924. Furthermore, our findings show that transient exposure to this new investigational drug should be useful for controlling p53-negative cancer cells, which often pose significant clinical challenge.
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, Virginia, USA.
authors.forename: Jie Jessie
authors.initials: JJ
authors.lastname: Lin
authors.forename: Michael A
authors.initials: MA
authors.lastname: Milhollen
authors.forename: Peter G
authors.initials: PG
authors.lastname: Smith
authors.forename: Usha
authors.initials: U
authors.lastname: Narayanan
authors.forename: Anindya
authors.initials: A
authors.lastname: Dutta
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D018797:Cell Cycle Proteins / Q000378:metabolism*; D016922:Cellular Senescence / Q000187:drug effects / Q000502:physiology; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics; D003517:Cyclopentanes / Q000494:pharmacology*; D004261:DNA Replication / Q000187:drug effects*; D045325:HCT116 Cells; D006801:Humans; D058990:Molecular Targeted Therapy / Q000379:methods; D000075687:NEDD8 Protein; D011743:Pyrimidines / Q000494:pharmacology*; D016196:S Phase / Q000187:drug effects* / Q000502:physiology; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics; D044767:Ubiquitin-Protein Ligases / Q000037:antagonists & inhibitors / Q000378:metabolism; D014452:Ubiquitins / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: C493956:CDKN1A protein, human; C467199:CDT1 protein, human; D018797:Cell Cycle Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; D003517:Cyclopentanes; D000075687:NEDD8 Protein; C082860:NEDD8 protein, human; D011743:Pyrimidines; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D014452:Ubiquitins; D044767:Ubiquitin-Protein Ligases; C539933:pevonedistat