title: Inhibition of Wee1 sensitizes cancer cells to antimetabolite chemotherapeutics in vitro and in vivo, independent of p53 functionality.
abstract: Inhibition of Wee1 is emerging as a novel therapeutic strategy for cancer, and some data suggest that cells with dysfunctional p53 are more sensitive to Wee1 inhibition combined with conventional chemotherapy than those with functional p53. We and others found that Wee1 inhibition sensitizes leukemia cells to cytarabine. Thus, we sought to determine whether chemosensitization by Wee1 inhibition is dependent on p53 dysfunction and whether combining Wee1 inhibition is tolerable and effective in vivo. Synergistic inhibition of proliferation with a Wee1 inhibitor in clinical development, MK1775, and cytarabine was observed in all acute myelogenous leukemia (AML) cell lines tested, regardless of p53 functionality. Mechanistic studies indicate that inhibition of Wee1 abrogates the S-phase checkpoint and augments apoptosis induced by cytarabine. In AML and lung cancer cell lines, genetic disruption of p53 did not alter the cells' enhanced sensitivity to antimetabolites with Wee1 inhibition. Finally, mice with AML were treated with cytarabine and/or MK1775. The combination of MK1775 and cytarabine was well tolerated in mice and enhanced the antileukemia effects of cytarabine, including survival. Thus, inhibition of Wee1 sensitizes hematologic and solid tumor cell lines to antimetabolite chemotherapeutics, whether p53 is functional or not, suggesting that the use of p53 mutation as a predictive biomarker for response to Wee1 inhibition may be restricted to certain cancers and/or chemotherapeutics. These data provide preclinical justification for testing MK1775 and cytarabine in patients with leukemia.
authors.affiliation: Corresponding Author: Christopher C. Porter, University of Colorado School of Medicine,12800 East 19th Avenue, RC1N 4101, Aurora, CO 80045. chris.porter@ucdenver.edu.
authors.forename: Annemie A
authors.initials: AA
authors.lastname: Van Linden
authors.forename: Dmitry
authors.initials: D
authors.lastname: Baturin
authors.forename: James B
authors.initials: JB
authors.lastname: Ford
authors.forename: Susan P
authors.initials: SP
authors.lastname: Fosmire
authors.forename: Lori
authors.initials: L
authors.lastname: Gardner
authors.forename: Christopher
authors.initials: C
authors.lastname: Korch
authors.forename: Philip
authors.initials: P
authors.lastname: Reigan
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Porter
mesh_terms: D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors*; D045744:Cell Line, Tumor; D019008:Drug Resistance, Neoplasm; D004357:Drug Synergism; D005260:Female; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy / Q000378:metabolism / Q000401:mortality; D051379:Mice; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors*; D011720:Pyrazoles / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology*; D011744:Pyrimidinones; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D023041:Xenograft Model Antitumor Assays
chemical_list: D000964:Antimetabolites, Antineoplastic; D018797:Cell Cycle Proteins; D009687:Nuclear Proteins; D011720:Pyrazoles; D011743:Pyrimidines; D011744:Pyrimidinones; D016159:Tumor Suppressor Protein p53; D011505:Protein-Tyrosine Kinases; C499349:WEE1 protein, human; C549567:adavosertib