Abstract 5770: Inhibition of KRAS G12D mutant with small molecules

Abstract

Abstract Background: RAS mutations are occurring at a high rate in colorectal cancer, lung cancer, and pancreatic cancer. RAS is family of small GTPase proteins with important roles in cell growth, differentiation, proliferation, and survival. There are three types of RAS genes: HRAS, KRAS, and NRAS. The The RAS gene is the most commonly found oncogene in human cancer. KRAS exhibits a highest mutation rate compared to those of HRAS and NRAS in various cancer types. Methods: Colorectal cell line LIM1215, SW48 and NSCLC cell line NCI-H1975, NCI-H838 were used for MTT assays. Apoptosis assay was performed using the annexin V-FITC apoptosis detection kit (BioBud, Cat. LS-02-100). Colony forming assay was performed with 6-well culture plates by seeding 500 cells/well. The expression levels of proteins involved in Q2a-induced signaling pathway were determined by Western blot. In vivo study was performed with tumor xenografts. HT-29 cells were implanted into the right flank of 5-week-old BALB/c nude mice. Tumor size was determined by measuring the diameter (width, length) of the tumor every two days with a digital caliper. All group mice sacrificed at day 19. Results: Patients with cancer involving KRAS mutations are resistant to therapeutics that target epidermal growth factor receptor and show poor outcomes. In addition, effective treatments that target G12D in KRAS have not been developed. Thus, therapeutic agents targeting the G12D mutation in KRAS are needed. In this study, we identified the Q2a compound, a quinazoline-based derivative that specifically acts on the KRAS G12D mutation. This compound induced cell apoptosis by reducing phosphorylation of AKT in the PI3K pathway downstream of KRAS. Q2a compound specifically inhibited the growth of KRAS G12D mutant cells. In addition, cells with the KRAS G12D mutation were more sensitive to Q2a compound compared to the sensitivity of wild-type cells and those with other KRAS mutations, resulting in apoptosis. Treatment with the Q2a compound also decreased C-RAF phosphorylation in the MAPK pathway, which is downstream of KRAS. In KRAS G12D-mutated colorectal cancer xenografts, Q2a compound inhibited tumor production without significant liver toxicity. Conclusion: Q2a compounds show potential as therapeutic agents that target KRAS G12D mutations in colorectal and pancreatic cancers. Kyewords: Anti-Cancer Drug, KRAS G12D Mutant, apoptosis, colon cancerJi Yoon Lee, Dae-Hee Lee*Department of Marine Bio Food Science, Gangneung-Wonju national University Citation Format: Dae-Hee Lee, Ji Yoon Lee. Inhibition of KRAS G12D mutant with small molecules [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5770.