@article{b5b67cb0f98e4bc8bc87f41702d8900a,
title = "Allosteric regulation of DNA binding and target residence time drive the cytotoxicity of phthalazinone-based PARP-1 inhibitors",
abstract = "Allosteric coupling between the DNA binding site to the NAD+-binding pocket drives PARP-1 activation. This allosteric communication occurs in the reverse direction such that NAD+ mimetics can enhance PARP-1's affinity for DNA, referred to as type I inhibition. The cellular effects of type I inhibition are unknown, largely because of the lack of potent, membrane-permeable type I inhibitors. Here we identify the phthalazinone inhibitor AZ0108 as a type I inhibitor. Unlike the structurally related inhibitor olaparib, AZ0108 induces replication stress in tumorigenic cells. Synthesis of analogs of AZ0108 revealed features of AZ0108 that are required for type I inhibition. One analog, Pip6, showed similar type I inhibition of PARP-1 but was ∼90-fold more cytotoxic than AZ0108. Washout experiments suggest that the enhanced cytotoxicity of Pip6 compared with AZ0108 is due to prolonged target residence time on PARP-1. Pip6 represents a new class of PARP-1 inhibitors that may have unique anticancer properties.",
keywords = "ADP-ribosylation, allosteric regulation, NAD-competitive inhibitors, PARPs, target residence time",
author = "Arnold, {Moriah R.} and Langelier, {Marie France} and Jessica Gartrell and Kirby, {Ilsa T.} and Sanderson, {Daniel J.} and Bejan, {Daniel S.} and Justina {\v S}ileikytė and Sundalam, {Sunil K.} and Shanthi Nagarajan and Parthiban Marimuthu and Duell, {Anna K.} and Shelat, {Anang A.} and Pascal, {John M.} and Cohen, {Michael S.}",
note = "Funding Information: We thank Dr. Jeffrey Johannes (AstraZeneca) for providing AZ0108. We thank Dr. M. Garabedian (New York University, Langone) for HEK 293 control and KO cell lines. We thank Dr. G. Timinszky (Hungarian Academy of Sciences) for the PARP-1-mCherry plasmid. All imaging and FACS experiments could not have been possible without help from Dr. S. Petrie (OHSU Advanced Light Microscopy Core) and Dr. S. Christensen and M. Lewis (OHSU Flow Cytometry Core). Last, a huge thanks to Cohen Lab members who helped with the revision process. P.M. gratefully acknowledges the Sigrid Jus{\'e}lius Foundation and Joe, Pentti, and Tor Borg Memorial Fund for computational and laboratory infrastructure; the bioinformatics infrastructure facility supported by Biocenter Finland , CSC-IT Center for Science (project 2000461 ) for computational facilities; Dr. J. Lehtonen for IT support; and especially thanks Prof. M. Johnson, SBL, {\AA}bo Akademi University, for providing the lab facility. This work was supported by grants from the NIH ( P30NS061800 and P30CA065823 , Dr. S. Petrie, OHSU Advanced Light Microscopy Core, Jungers Center), the St. Baldrick{\textquoteright}s Foundation (to A.A.S.), the Sarcoma Foundation of America (to A.A.S.), the Canadian Institutes of Health Research ( PJT173370 to J.M.P.), the Pew Biomedical Scholars program (to M.S.C.), the OHSU Biomedical Innovation Program (to M.S.C.), and the NIH NINDS ( 2R01NS088629 to M.S.C.). Funding Information: We thank Dr. Jeffrey Johannes (AstraZeneca) for providing AZ0108. We thank Dr. M. Garabedian (New York University, Langone) for HEK 293 control and KO cell lines. We thank Dr. G. Timinszky (Hungarian Academy of Sciences) for the PARP-1-mCherry plasmid. All imaging and FACS experiments could not have been possible without help from Dr. S. Petrie (OHSU Advanced Light Microscopy Core) and Dr. S. Christensen and M. Lewis (OHSU Flow Cytometry Core). Last, a huge thanks to Cohen Lab members who helped with the revision process. P.M. gratefully acknowledges the Sigrid Jus{\'e}lius Foundation and Joe, Pentti, and Tor Borg Memorial Fund for computational and laboratory infrastructure; the bioinformatics infrastructure facility supported by Biocenter Finland, CSC-IT Center for Science (project 2000461) for computational facilities; Dr. J. Lehtonen for IT support; and especially thanks Prof. M. Johnson, SBL, {\AA}bo Akademi University, for providing the lab facility. This work was supported by grants from the NIH (P30NS061800 and P30CA065823, Dr. S. Petrie, OHSU Advanced Light Microscopy Core, Jungers Center), the St. Baldrick's Foundation (to A.A.S.), the Sarcoma Foundation of America (to A.A.S.), the Canadian Institutes of Health Research (PJT173370 to J.M.P.), the Pew Biomedical Scholars program (to M.S.C.), the OHSU Biomedical Innovation Program (to M.S.C.), and the NIH NINDS (2R01NS088629 to M.S.C.). M.R.A. and M.S.C. designed the experiments. All HEK293T cell experiments were performed by M.R.A. or D.S.B. I.T.K. synthesized Pip1–Pip4, M.S.C. synthesized Pip5 and Pip6, and S.K.S. synthesized ad-olaparib. In vitro PARP-1 activity assays were performed by I.T.K. and D.J.S. In vitro fluorescence polarization assays were performed by M.-F.L. and J.M.P. J.{\v S}. performed photoaffinity labeling experiments using ad-olaparib. S.N. and P.M. performed molecular modeling and analysis. J.G. and A.A.S. performed all experiments in ES8 cells. M.R.A. and M.S.C. wrote the manuscript with input from the other authors. M.R.A. and M.S.C. are inventors on a patent related to the compounds generated from this manuscript. M.S.C. is a founder of Tilikum Therapeutics. Publisher Copyright: {\textcopyright} 2022 Elsevier Ltd",
year = "2022",
month = dec,
day = "15",
doi = "10.1016/j.chembiol.2022.11.006",
language = "English",
volume = "29",
pages = "1694--1708.e10",
journal = "Cell Chemical Biology",
issn = "2451-9456",
publisher = "Cell Press",
number = "12",
}