# Regulation of DNA replication kinetics by BRCA2 after DNA damage

> **NIH NIH R01** · RBHS -CANCER INSTITUTE OF NEW JERSEY · 2021 · $344,772

## Abstract

Germline mutations in BRCA2 predispose carriers to breast, ovarian, pancreatic, and other cancers. The gene
encodes a very large protein that plays critical roles in genome integrity control by promoting homologous
recombination (HR)-mediated repair of DNA double strand breaks (DSBs), DNA damage-induced cell cycle
checkpoint, and stability of stalled DNA replication forks, etc. Besides, BRCA2 may play a direct role in DNA
replication, as its mutant cells have long been known to have the so-called radio-resistant DNA synthesis
(RDS) phenotype, which reflects a defect in the intra-S phase checkpoint, a mechanism that slows down DNA
replication after DNA damage presumably to allow time for DNA repair and prevent replication of damage
DNA. However, the potential role of BRCA2 in DNA replication initiation or elongation has not been defined. In
our preliminary studies, we found that BRCA2 interacts with an essential DNA replication factor, MCM10, and
that this interaction restrains replication fork progression, promotes fork stalling and sustains origin firing after
DNA damage. We hypothesize that BRCA2 regulates DNA replication kinetics after DNA damage through its
interaction with MCM10 and that a dysregulation of replication kinetics after DNA damage, or intra-S phase
checkpoint defect, leads to increased mutation rate, cancer development and therapy resistance. We propose
3 specific aims to test the hypotheses. In Aim 1, we will define the mechanisms of BRCA2 function in DNA
replication kinetics after DNA damage. In Aim 2, we will determine the role of the BRCA2-MCM10 interaction in
DNA replication fidelity and cancer cell response to DNA damaging therapies. In Aim 3, we will determine the
role of BRCA2-MCM10 interaction in spontaneous and radiation-induced tumor development. Our findings and
proposed studies will elucidate key mechanisms of BRCA2 function in DNA replication, provide new insights
into the regulation of replication kinetics after DNA damage, and define the impact of RDS and replication
kinetics dysregulation on cancer development and tumor relapse after radiation and chemotherapy.

## Key facts

- **NIH application ID:** 10278027
- **Project number:** 1R01CA262227-01
- **Recipient organization:** RBHS -CANCER INSTITUTE OF NEW JERSEY
- **Principal Investigator:** Bing Xia
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $344,772
- **Award type:** 1
- **Project period:** 2021-07-01 → 2026-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10278027

## Citation

> US National Institutes of Health, RePORTER application 10278027, Regulation of DNA replication kinetics by BRCA2 after DNA damage (1R01CA262227-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10278027. Licensed CC0.

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