Abstract 6569: KLIPP: Precision targeting of cancer with CRISPR

Abstract Current cancer therapeutic treatments are typically associated with significant collateral damage to normal tissues and the emergence of treatment resistance. Thus, there is an unmet need to develop therapies that are uniquely cancer specific and unhindered by the emergence of resistance. We have developed an RNA therapy approach based on CRISPR technology, known as “KLIPP”, that targets cancer-specific structural variant junctions (SVJs), a so far untapped cancer “Achilles heel”, that are highly abundant across cancer types. KLIPP uses a “split enzyme” system consisting of dCas9 conjugated to an endonuclease, Fok1, that requires dimerization for its activity. By designing sgRNAs that bind to sequences flanking the cancer-specific SVJs, Fok1-dCas9 dimers are formed, leading to the induction of DNA double strand breaks (DSBs) specifically at SVJs in cancer cells. We verify induction of DSBs by γH2AX foci staining in the nucleus of KLIPP-treated cells and resulting loss of clonogenic survival and induction of apoptosis, while cells lacking the targeted SVJs are unaffected. Importantly, we show elimination of orthotopic bladder cancer tumors in vivo after turning on expression of the KLIPP reagents by doxycycline in the drinking water. Finally, we show successful lipid nanoparticle delivery of KLIPP reagents to orthotopic bladder tumors in vivo using catheter-mediated delivery, leading to specific targeting of bladder cancer cells. Independently of the cancer-driving mutations, the omnipresence of cancer-specific SVJs is exploited by KLIPP to force cancer cells into apoptosis while leaving normal cells unperturbed. We believe that the successful implementation of precision KLIPP therapy could be transformative for the treatment of cancer patients. Citation Format: Mats Ljungman, Huibin Yang, Radhika Suhas Hulbatte, Natalie Gratsch, Alan Kelher, John Raupp, Yin Wang, Kristen Hong Dorsey, Troy Halseth, Anna Schwendeman, Philip Palmbos. KLIPP: Precision targeting of cancer with CRISPR [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 6569.