Open AccessCRISPR-Cas9 screens identify regulators of antibody–drug conjugate toxicity
Author(s) -
C. Kimberly Tsui,
Robyn M. Barfield,
Curt R. Fischer,
David W. Morgens,
Amy Li,
Benjamin Smith,
Melissa A. Gray,
Carolyn R. Bertozzi,
David Rabuka,
Michael C. Bassik
Publication year - 2019
Publication title -
nature chemical biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.412
H-Index - 216
eISSN - 1552-4469
pISSN - 1552-4450
DOI - 10.1038/s41589-019-0342-2
Subject(s) - endosome , trastuzumab emtansine , internalization , crispr , antibody drug conjugate , phospholipidosis , biology , chemistry , cancer , cancer research , trastuzumab , microbiology and biotechnology , cell , biochemistry , intracellular , breast cancer , antibody , monoclonal antibody , gene , genetics , immunology , phospholipid , membrane
Antibody-drug conjugates (ADCs) selectively deliver chemotherapeutic agents to target cells and are important cancer therapeutics. However, the mechanisms by which ADCs are internalized and activated remain unclear. Using CRISPR-Cas9 screens, we uncover many known and novel endolysosomal regulators as modulators of ADC toxicity. We identify and characterize C18ORF8/RMC1 as a regulator of ADC toxicity through its role in endosomal maturation. Through comparative analysis of screens with ADCs bearing different linkers, we show that a subset of late endolysosomal regulators selectively influence toxicity of noncleavable linker ADCs. Surprisingly, we find cleavable valine-citrulline linkers can be processed rapidly after internalization without lysosomal delivery. Lastly, we show that sialic acid depletion enhances ADC lysosomal delivery and killing in diverse cancer cell types, including with FDA (US Food and Drug Administration)-approved trastuzumab emtansine (T-DM1) in Her2-positive breast cancer cells. Together, these results reveal new regulators of endolysosomal trafficking, provide important insights for ADC design and identify candidate combination therapy targets.