Identification of the nucleotide-free state as a therapeutic vulnerability for inhibition of selected oncogenic RAS mutants
Imran Khan,
Akiko Koide,
Mariyam Zuberi,
Gayatri Ketavarapu,
Eric Denbaum,
Kai Wen Teng,
J. Matthew Rhett,
Russell Spencer-Smith,
G. Aaron Hobbs,
Ernest Ramsay Camp,
Shohei Koide,
John P. O'Bryan
Affiliations
Imran Khan
Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA; Ralph H. Johnson VA Medical Center, Charleston, SC 29401, USA; Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612, USA
Akiko Koide
Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, USA; Department of Medicine, New York University School of Medicine, New York, NY 10016, USA
Mariyam Zuberi
Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
Gayatri Ketavarapu
Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, USA
Eric Denbaum
Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, USA
Kai Wen Teng
Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, USA
J. Matthew Rhett
Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
Russell Spencer-Smith
Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612, USA
G. Aaron Hobbs
Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
Ernest Ramsay Camp
Department of Surgery, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA; Ralph H. Johnson VA Medical Center, Charleston, SC 29401, USA
Shohei Koide
Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, USA; Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA; Corresponding author
John P. O'Bryan
Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA; Ralph H. Johnson VA Medical Center, Charleston, SC 29401, USA; Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612, USA; Corresponding author
Summary: RAS guanosine triphosphatases (GTPases) are mutated in nearly 20% of human tumors, making them an attractive therapeutic target. Following our discovery that nucleotide-free RAS (apo RAS) regulates cell signaling, we selectively target this state as an approach to inhibit RAS function. Here, we describe the R15 monobody that exclusively binds the apo state of all three RAS isoforms in vitro, regardless of the mutation status, and captures RAS in the apo state in cells. R15 inhibits the signaling and transforming activity of a subset of RAS mutants with elevated intrinsic nucleotide exchange rates (i.e., fast exchange mutants). Intracellular expression of R15 reduces the tumor-forming capacity of cancer cell lines driven by select RAS mutants and KRAS(G12D)-mutant patient-derived xenografts (PDXs). Thus, our approach establishes an opportunity to selectively inhibit a subset of RAS mutants by targeting the apo state with drug-like molecules.
