Journal Article

Identification of regulators of poly-ADP-ribose polymerase inhibitor response through complementary CRISPR knockout and activation screens

Wang, Hong-Gang, Thakar, Tanay, Dhoonmoon, Ashna, Nicolae, Claudia M., Sharma, Anchal, Clements, Kristen E., Schleicher, Emily M., De, Subhajyoti, Tolman, Nathanial J., Liang, Xinwen, Moldovan, George-Lucian, Hale, Anastasia, Imamura Kawasawa, Yuka

2020

Overview

Inhibitors of poly-ADP-ribose polymerase 1 (PARPi) are highly effective in killing cells deficient in homologous recombination (HR); thus, PARPi have been clinically utilized to successfully treat BRCA2-mutant tumors. However, positive response to PARPi is not universal, even among patients with HR-deficiency. Here, we present the results of genome-wide CRISPR knockout and activation screens which reveal genetic determinants of PARPi response in wildtype or BRCA2-knockout cells. Strikingly, we report that depletion of the ubiquitin ligase HUWE1, or the histone acetyltransferase KAT5, top hits from our screens, robustly reverses the PARPi sensitivity caused by BRCA2-deficiency. We identify distinct mechanisms of resistance, in which HUWE1 loss increases RAD51 levels to partially restore HR, whereas KAT5 depletion rewires double strand break repair by promoting 53BP1 binding to double-strand breaks. Our work provides a comprehensive set of putative biomarkers that advance understanding of PARPi response, and identifies novel pathways of PARPi resistance in BRCA2-deficient cells. Mutations in the homologous recombination proteins BRCA1 and BRCA2 can sensitize cells to treatment with inhibitors of poly-ADP-ribose polymerase 1 (PARPi), but resistance to the treatment can occur. Here the authors by genome-wide CRISPR knockout and activation screens reveal novel pathways of PARPi resistance in BRCA2-deficient cells.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 13/1 / 13/106 / 13/31 / 13/51 / 13/89 / 14 / 14/34 / 38 / 38/23 / 38/47 / 631/337/1427 / 631/67/1059 / Adenosine diphosphate / Biomarkers / BRCA1 protein / BRCA2 protein / BRCA2 Protein - genetics / BRCA2 Protein - metabolism / Breast cancer / Clustered Regularly Interspaced Short Palindromic Repeats / CRISPR / Depletion / DNA Damage / DNA Repair / Gene Knockout Techniques / Genomes / HeLa Cells / Histone acetyltransferase / Homologous recombination / Homologous Recombination - drug effects / Homology / Humanities and Social Sciences / Humans / Huwe1 protein / Inhibitors / Lysine Acetyltransferase 5 - metabolism / Mad2 Proteins - metabolism / multidisciplinary / Mutation / Poly(ADP-ribose) Polymerase Inhibitors - isolation & purification / Poly(ADP-ribose) Polymerase Inhibitors - pharmacology / Poly(ADP-ribose) Polymerases - drug effects / Rad51 Recombinase - genetics / Rad51 Recombinase - metabolism / Regulators / Ribose / Science / Science (multidisciplinary) / Tumor Suppressor p53-Binding Protein 1 / Tumor Suppressor Proteins - genetics / Tumor Suppressor Proteins - metabolism / Tumors / Ubiquitin / Ubiquitin-protein ligase / Ubiquitin-Protein Ligases - genetics / Ubiquitin-Protein Ligases - metabolism