# Genome-wide DNA Secondary Structure Analysis to Investigate DNA Fragility

> **NIH NIH R01** · UNIVERSITY OF VIRGINIA · 2021 · $345,137

## Abstract

Project Summary/Abstract:
 Both physiological DNA breaks occurring during DNA metabolic processes and pathological DNA breaks
responding to a wide range of stresses, contribute to the outcome of human genome instability. DNA fragility
generated by alternative DNA secondary structures is a known cause of many human diseases, and also occurs
in normal DNA processes. Formation of these structures can arise from single-stranded DNA when the DNA
duplex is unwound during DNA processes such as replication and transcription, and thus can be affected by
cellular activities, nucleotide sequences, and chemical exposures. Here we will examine if DNA regions
having potential to form stable secondary structures when unwound during cell processes, can serve
as signals for topoisomerase II (TOP2) to recognize and cleave, and lead to the removal of the excessive
supercoiling. We have carried out a computational evaluation of the entire available human genome sequence
for optimal ability to fold single-stranded sequences into multiple-hairpin structures, and identified sites of highly
stable DNA secondary structures throughout the genome. We will measure TOP2-mediated DNA breaks at
these sites upon changes in DNA supercoiling from cell activities, then analyze TOP2-cleaved sites to identify
structural features, and examine if DNA secondary structures influence the removal of TOP2 cleavage
complexes. TOP2-mediated breaks are also often associated with pathological damage due to the use of TOP2
inhibitors as anticancer drugs. Many DNA secondary structure-rich and fragile regions are located within cancer-
specific translocation-participating gene regions, including acute myeloid leukemia (AML)-rearranged regions.
We will determine whether DNA fragility at these regions can serve as a biomarker for assessing the
potential development of cancer-causing rearrangements. We will first test if DNA fragility at gene regions
of AML rearrangements is sensitive to various chemotherapeutic agents, and if this sensitivity leads to the
formation of AML rearrangements in human cells. Then, to test if this sensitivity can predict the rearrangement
formation in patients, we will examine DNA breakage at these regions in normal cells of AML patients with the
AML rearrangements, compared to that of normal individuals, as a means to evaluate individual susceptibility
to AML. These experiments will facilitate the clinical application of using DNA fragility as a biomarker. With
personalized medicine in mind, we will evaluate the effect of naturally occurring sequence variants on the
fragility of the break-prone and AML translocation-participating gene regions, to further identify
structure characteristics contributing to DNA fragility, and to reveal an unexploited consequence of
non-coding variants. Our preliminary results suggest that sequence variants can influence DNA break
frequency of the region by changing the extent or the type of secondary structure forming ability. This proposal...

## Key facts

- **NIH application ID:** 10119032
- **Project number:** 2R01GM101192-06A1
- **Recipient organization:** UNIVERSITY OF VIRGINIA
- **Principal Investigator:** YUH-HWA WANG
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $345,137
- **Award type:** 2
- **Project period:** 2013-07-01 → 2024-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10119032

## Citation

> US National Institutes of Health, RePORTER application 10119032, Genome-wide DNA Secondary Structure Analysis to Investigate DNA Fragility (2R01GM101192-06A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10119032. Licensed CC0.

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