36ok
Tri-complex of RMC-8839, KRAS G13C, and CypA
Structural highlights
DiseaseRASK_HUMAN Defects in KRAS are a cause of acute myelogenous leukemia (AML) [MIM:601626. AML is a malignant disease in which hematopoietic precursors are arrested in an early stage of development.[1] Defects in KRAS are a cause of juvenile myelomonocytic leukemia (JMML) [MIM:607785. JMML is a pediatric myelodysplastic syndrome that constitutes approximately 30% of childhood cases of myelodysplastic syndrome (MDS) and 2% of leukemia. It is characterized by leukocytosis with tissue infiltration and in vitro hypersensitivity of myeloid progenitors to granulocyte-macrophage colony stimulating factor. Defects in KRAS are the cause of Noonan syndrome type 3 (NS3) [MIM:609942. Noonan syndrome (NS) [MIM:163950 is a disorder characterized by dysmorphic facial features, short stature, hypertelorism, cardiac anomalies, deafness, motor delay, and a bleeding diathesis. It is a genetically heterogeneous and relatively common syndrome, with an estimated incidence of 1 in 1000-2500 live births. Rarely, NS is associated with juvenile myelomonocytic leukemia (JMML). NS3 inheritance is autosomal dominant.[2] [3] [4] [5] [6] [7] Defects in KRAS are a cause of gastric cancer (GASC) [MIM:613659; also called gastric cancer intestinal or stomach cancer. Gastric cancer is a malignant disease which starts in the stomach, can spread to the esophagus or the small intestine, and can extend through the stomach wall to nearby lymph nodes and organs. It also can metastasize to other parts of the body. The term gastric cancer or gastric carcinoma refers to adenocarcinoma of the stomach that accounts for most of all gastric malignant tumors. Two main histologic types are recognized, diffuse type and intestinal type carcinomas. Diffuse tumors are poorly differentiated infiltrating lesions, resulting in thickening of the stomach. In contrast, intestinal tumors are usually exophytic, often ulcerating, and associated with intestinal metaplasia of the stomach, most often observed in sporadic disease.[8] [9] [10] Note=Defects in KRAS are a cause of pylocytic astrocytoma (PA). Pylocytic astrocytomas are neoplasms of the brain and spinal cord derived from glial cells which vary from histologically benign forms to highly anaplastic and malignant tumors.[11] Defects in KRAS are a cause of cardiofaciocutaneous syndrome (CFC syndrome) [MIM:115150; also known as cardio-facio-cutaneous syndrome. CFC syndrome is characterized by a distinctive facial appearance, heart defects and mental retardation. Heart defects include pulmonic stenosis, atrial septal defects and hypertrophic cardiomyopathy. Some affected individuals present with ectodermal abnormalities such as sparse, friable hair, hyperkeratotic skin lesions and a generalized ichthyosis-like condition. Typical facial features are similar to Noonan syndrome. They include high forehead with bitemporal constriction, hypoplastic supraorbital ridges, downslanting palpebral fissures, a depressed nasal bridge, and posteriorly angulated ears with prominent helices. The inheritance of CFC syndrome is autosomal dominant. Note=KRAS mutations are involved in cancer development. FunctionRASK_HUMAN Ras proteins bind GDP/GTP and possess intrinsic GTPase activity. Publication Abstract from PubMedCovalent KRAS G12C inhibitors have changed the treatment landscape for NSCLC and CRC patients, but numerous RAS-mutant cancers lack approved targeted therapies. Here we describe RMC-8839, an oral RAS(ON) G13C-selective, covalent, tri-complex inhibitor that induced tumor regressions in selected KRAS G13C-mutant xenograft models. However, one-third of KRAS G13C-mutant human cancer cell lines in vitro showed incomplete RAS pathway suppression despite near-complete KRAS G13C engagement, suggesting a role for wild-type RAS(ON). We find that codon 13-mutant RAS differs from other KRAS mutations, exhibiting decreased stability, increased nucleotide exchange, and substantial intrinsic and GAP-stimulated GTP hydrolysis, which decreases oncogenicity. Furthermore, co-occurring RAS pathway mutations leading to increased wild-type RAS activation are enriched in codon 13 mutant tumors. Consistent with a role for wild-type RAS(ON) signaling, combination of RMC-8839 with a RAS(ON) multi-selective inhibitor resulted in deeper inhibition of KRAS G13C-mutant xenograft tumor growth than either inhibitor alone. Selective Inhibition of KRASG13C Reveals an Increased Dependence on Wild-Type RAS Isoforms in Codon 13 RAS-Mutant Cancers.,Seamon KJ, Zhuang Y, Yang YC, Chakraborty S, Cregg J, Tomlinson ACA, Gould A, Ahler E, Maldonato BJ, Spradlin JN, Pota K, Weller C, Marquez A, Wang Z, Koltun ES, Knox JE, Gill AL, Smith JAM, Singh M, Jiang J, Wildes D, Holderfield M Cancer Discov. 2026 Jun 22. doi: 10.1158/2159-8290.CD-25-0886. PMID:42329095[12] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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