How the APE2 DNA-repair protein helps breast cancers that can't use homologous recombination

Deciphering the function of the APE2 nuclease during repair by alternative end-joining and its role in HR-deficient cells

NIH-funded research University of Colorado · NIH-11239802

This project looks at whether disrupting the APE2 protein can make breast cancers that can't repair DNA properly—including tumors that resist PARP inhibitors—more likely to die.

Quick facts

Grant typeR01 grant
Study typeNIH-funded research
Funding institutionUniversity of Colorado NIH-funded
Lab location1 site (Boulder, UNITED STATES)
Project IDNIH-11239802 on NIH RePORTER

What this research studies

Researchers use genome-wide CRISPR screens and biochemical assays to map how APE2 supports an alternative DNA repair route called alternative end-joining (Alt-EJ). They perform reporter-based repair tests and telomere-fusion experiments in HR-deficient cancer cell lines and models to see how dependent these cells are on APE2. The team will define APE2’s enzymatic role in Alt-EJ and test whether its loss or inhibition sensitizes tumors that lack homologous recombination. Results are intended to highlight potential drug targets and biomarkers that could guide future therapies for PARP-resistant cancers.

Who could benefit from this research

Good fit: People with HR-deficient breast cancer—such as those with BRCA1/2-related tumors—or patients whose tumors have become resistant to PARP inhibitors would be the most relevant group.

Not a fit: Patients whose tumors are homologous recombination–proficient or who have cancers unrelated to HR defects are unlikely to benefit directly from this specific research.

Why it matters

Potential benefit: If successful, this work could identify new drug targets to kill HR-deficient breast cancers, including tumors that no longer respond to PARP inhibitors.

How similar studies have performed: PARP inhibitors are an established therapy for HR-deficient cancers, but targeting Alt-EJ or APE2 is a newer strategy supported mainly by early preclinical data rather than clinical success to date.

Where this research is happening

Boulder, UNITED STATES

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.
Conditions Breast Cancer
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.