Why some ER-positive breast cancers grow without estrogen

Mechanism of estrogen independent proliferation in ER+ breast cancer cells

NIH-funded research Beckman Research Institute/city of Hope · NIH-11166394

Learning how some ER-positive breast cancers start growing again without estrogen, to help people with ER+ breast cancer get better treatment.

Quick facts

Grant typeU01 cooperative agreement
Study typeNIH-funded research
Funding institutionBeckman Research Institute/city of Hope NIH-funded
Lab location1 site (Duarte, United States)
Project IDNIH-11166394 on NIH RePORTER

What this research studies

Researchers will compare tumor samples taken before and after hormone therapy and CDK4/6 inhibitor treatment to see which cancer cells survive and why. They will use single-cell gene-reading technology and lab-grown matched cancer cells to track changes in estrogen signaling, JNK pathway activity, and cell-cycle control. The team will build a mechanistic model linking estrogen, JNK signaling, and CDK4/6 regulation to pinpoint how tumors bypass hormone dependence. Findings will guide ideas for therapies to prevent or reverse resistance in early-stage ER+ breast cancer.

Who could benefit from this research

Good fit: People with early-stage ER-positive, HER2-negative breast cancer who are receiving or can provide tumor biopsies before and after endocrine and/or CDK4/6 inhibitor treatment.

Not a fit: Patients with HER2-positive or triple-negative breast cancer, or those not receiving endocrine or CDK4/6 therapy, are unlikely to receive direct benefit from this work.

Why it matters

Potential benefit: Could reveal targets or strategies to prevent or overcome resistance to hormone plus CDK4/6 drugs in early-stage ER-positive, HER2-negative breast cancer.

How similar studies have performed: Combining CDK4/6 inhibitors with endocrine therapy has improved outcomes in metastatic ER+ breast cancer, but applying single-cell approaches to understand resistance in earlier-stage disease is relatively new.

Where this research is happening

Duarte, 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 CancerBreast Cancer CellBreast Cancer PatientCancer Control
Last reviewed 2026-06-13 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.