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.
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.
Cell Rep. 2022 Feb 8;38(6):110322. doi: 10.1016/j.celrep.2022.110322.
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.
RAS 鸟嘌呤三核苷酸酶（GTPases）在近 20%的人类肿瘤中发生突变，使其成为一个有吸引力的治疗靶点。在发现无核苷酸的 RAS（apoRAS）调节细胞信号后，我们将这种状态作为抑制 RAS 功能的一种方法进行了选择性靶向。在这里，我们描述了 R15 单域抗体，它可以在体外特异性结合所有三种 RAS 同工型的 apo 状态，无论突变状态如何，并在细胞中捕获 apoRAS。R15 抑制了一组具有较高内在核苷酸交换率的 RAS 突变体（即快速交换突变体）的信号转导和转化活性。细胞内表达 R15 可降低由特定 RAS 突变体和 KRAS(G12D)突变患者来源异种移植（PDX）驱动的癌细胞系的肿瘤形成能力。因此，我们的方法为通过用类似药物的分子靶向 apo 状态来选择性抑制一组 RAS 突变体提供了机会。
