# Improving CRISPR Based Prime Gene Editing For Large Fragment Edits

> **NIH NIH F31** · UNIVERSITY OF PENNSYLVANIA · 2022 · $49,189

## Abstract

Project Summary: Genome editing tools provide methods to study and manipulate the genome. This has
allowed for the development of cellular and animal-based models to study the pathological basis of many
diseases. Over the last ten years, the rapid development of CRISPR-Cas based genome editing tools has driven
advances in the biological sciences and has shown incredible utility in a wide range of fields ranging from basic
research to clinical trials. Prime Editing (PE) is a newly developed CRISPR-Cas9 based tool that directly rewrites
DNA sequences and has been shown to perform precise targeted insertions, deletions, and all 12 possible
classes of point mutations without requiring DSBs. While this technology holds great promise, further study is
needed to understand DNA repair mechanisms that result in productive editing and delivery strategies for the
PE system to allow for broad applicability of this technology.
In my preliminary studies, I have shown that modulation of key components of the PE system improves editing
efficiencies. Additionally, I have condensed the published lentiviral system to a dual selection lentiviral system
that is suitable for a wide range of cell types. The goal of this study is to further develop a PE platform
capable of large fragment edits for functional sequence insertions. In aim 1, I will use structure-guided
mutagenesis to generate a PE mutant better able to accommodate large fragment edits. In aim 2, I will use my
generated tool to endogenously tag BRD4 isoforms with a functional sequence to characterize their roles in
leukemia. Even though BRD4 is a therapeutic target with more than 20 inhibitors in clinical trials, these
nonspecific drugs target several members of the BET family and all BRD4 isoforms, which are required for normal
cellular function. Since this target lacks commercially available, isoform specific ChIP-grade antibodies and has
unique targetable C terminal regions, it serves as a practical and disease relevant target to demonstrate proof
of concept. Ultimately, development of this method will provide an addition to the CRISPR-Cas9 toolbox
capable of numerous other tasks.

## Key facts

- **NIH application ID:** 10387115
- **Project number:** 1F31HG012312-01
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Chad Komar
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $49,189
- **Award type:** 1
- **Project period:** 2021-12-01 → 2022-10-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10387115

## Citation

> US National Institutes of Health, RePORTER application 10387115, Improving CRISPR Based Prime Gene Editing For Large Fragment Edits (1F31HG012312-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10387115. Licensed CC0.

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