Abstract 3971: Developing cancer cell based in vitro and in vivo models with CRISPR-mediated knock-in technology for anti-tumor drug discovery

Abstract

Abstract Human cancer cell lines have long been applied for anti-tumor drug discovery considering their acquired genomic diversity of different carcinomas. Genetic engineering based on cancer cell lines is no doubt a useful and promising approach in induction of new therapeutic targets/elements while maintaining intrinsic characteristics of original cell in parallel. Recently, the emergence of CRISPR knock-in technology has accelerated precise editing across whole genome, from gene depletion, small fragment insertions to site-direct mutations, thereby prompting our understanding of the influence of a specific oncotarget in given tumor genetic background. Herein, by employing CRISPR/Cas9 system, two human cancer cell line-based, inheritable drug resistance models were established where the mutation site C481S of BTK in REC-1 conferred resistance to Ibrutinib and the mutation site R537S/D538G of ESR1 exerted resistance to Fulvestrant in MCF-7. In addition, the engineered cell models also enable the mechanism characterization and development of viable therapeutic agents targeting those oncogenic-driver mutations in a subtype of cancers. The murine colon cancer cell line CT26, which harbors KRASG12D mutation, was genetically modified to express KRASG12C protein to allow for an expandable pocket providing opportunities for compound recruitment. The resultant KRASG12C CT26 cell line showed pronounced inhibitory effect after treatment with AMG510. More interestingly, the therapeutic combination involving both AMG510 and anti-PD1 antibodies demonstrated more effective anti-tumor activities when compared to monotherapy. Moreover, CRIPSR-mediated engineered knock-in cells with a traceable tag linked to endogenous oncotarget also exhibit capability in new therapeutic modality discovery. Based on HiBiT protein tagging technology, we generated a series of HiBiT knock-in cell lines for real-time cell-based protein degradation analysis on various compelling targets, such as ESR1, KRAS, and BRD4, et al. Thereby, the construction of these in vitro and in vivo models with the ease of CRISPR KI technology is indispensable in new generation of therapeutic drug exploration. Citation Format: Nengwei Xu, Reifeng Wang, Jian Xiang, Qingyang Gu, Xiangnan Qiang. Developing cancer cell based in vitro and in vivo models with CRISPR-mediated knock-in technology for anti-tumor drug discovery. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3971.