title: Inhibition of DHHC20-Mediated EGFR Palmitoylation Creates a Dependence on EGFR Signaling.
abstract: Inappropriate activation of the receptor tyrosine kinase EGFR contributes to a variety of human malignancies. Here we show a mechanism to induce vulnerability to an existing first line treatment for EGFR-driven cancers. We find that inhibiting the palmitoyltransferase DHHC20 creates a dependence on EGFR signaling for cancer cell survival. The loss of palmitoylation increases sustained EGFR signal activation and sensitizes cells to EGFR tyrosine kinase inhibition. Our work shows that the reversible modification of EGFR with palmitate "pins" the unstructured C-terminal tail to the plasma membrane, impeding EGFR activation. We identify by mass spectrometry palmitoylated cysteine residues within the C-terminal tail where mutation of the cysteine residues to alanine is sufficient to activate EGFR signaling promoting cell migration and transformation. Our results reveal that the targeting of a peripheral modulator of EGFR signaling, DHHC20, causes a loss of signal regulation and susceptibility to EGFR inhibitor-induced cell death.
authors.affiliation: Department of Cancer Biology, University of Pennsylvania, Philadelphia, PA 19104; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104.
authors.forename: Kristin B
authors.initials: KB
authors.lastname: Runkle
authors.affiliation: Department of Cancer Biology, University of Pennsylvania, Philadelphia, PA 19104; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104.
authors.forename: Akriti
authors.initials: A
authors.lastname: Kharbanda
authors.affiliation: Department of Cancer Biology, University of Pennsylvania, Philadelphia, PA 19104; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104.
authors.forename: Ewa
authors.initials: E
authors.lastname: Stypulkowski
authors.affiliation: Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104.
authors.forename: Xing-Jun
authors.initials: XJ
authors.lastname: Cao
authors.affiliation: Department of Cancer Biology, University of Pennsylvania, Philadelphia, PA 19104; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104.
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Garcia
authors.affiliation: Department of Cancer Biology, University of Pennsylvania, Philadelphia, PA 19104; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104. Electronic address: ewitze@exchange.upenn.edu.
authors.forename: Eric S
authors.initials: ES
authors.lastname: Witze
mesh_terms: D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D001943:Breast Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D016923:Cell Death; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D003545:Cysteine; D004705:Endocytosis; D004815:Epidermal Growth Factor / Q000494:pharmacology; D066246:ErbB Receptors / Q000737:chemistry / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D051380:GRB2 Adaptor Protein / Q000378:metabolism; D000077156:Gefitinib; D057809:HEK293 Cells; D006801:Humans; D054878:Lipoylation; D013058:Mass Spectrometry; D051379:Mice; D009154:Mutation; D041681:NIH 3T3 Cells; D011487:Protein Conformation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D059748:Proteolysis; D011799:Quinazolines / Q000494:pharmacology; D034622:RNA Interference; D015398:Signal Transduction / Q000187:drug effects; D013329:Structure-Activity Relationship; D014162:Transfection
chemical_list: D000970:Antineoplastic Agents; D051380:GRB2 Adaptor Protein; C495948:GRB2 protein, human; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D004815:Epidermal Growth Factor; D000217:Acyltransferases; C550982:ZDHHC20 protein, human; C512478:EGFR protein, human; D066246:ErbB Receptors; D003545:Cysteine; D000077156:Gefitinib