• Press Release

Novel Therapeutic Target Discovered for Estrogen Receptor Positive (ER+) Breast Cancer

Mount Sinai researchers identify new protein in a common subtype of breast cancer which can potentially offer more effective therapies for the future

  • New York, NY
  • (November 17, 2017)

Researchers at the Icahn School of Medicine at Mount Sinai have identified a protein that can be targeted to suppress growth of a common type of breast cancer known as “estrogen receptor positive” (ER+), including ER+ cancers that are resistant to standard treatments.

The protein, tyrosine kinase 6 (PTK6), is an enzyme molecule that is highly expressed in multiple tumor types, including prostate, ovarian, and breast cancers. It can promote cancer cell survival and growth of ER+ breast cancer cells. The study, titled "PTK6 regulates growth and survival of endocrine therapy-resistant ER+ breast cancer cells," was published in an online study today in NPJ Breast Cancer.

“Never before has PTK6 inhibition been shown to inhibit growth and induce cell death of ER+ breast cancer cells, including those resistant to standard treatments for this subtype such as tamoxifen,” said Hanna Irie, MD, PhD, Assistant Professor of Medicine (Hematology and Medical Oncology) and Oncological Sciences at The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, and senior author of the study. “We are excited and gratified by these remarkable results, which could lead to a new way to treat these drug resistant metastases of ER+ breast cancers and/or prevent their metastases in the first place.”

According to Dr. Irie, the research is especially important because it supports the potential therapeutic value of targeting PTK6 in ER+ breast cancers, which constitute the most common subtype of breast cancer. Approximately 65 percent of all breast cancers express the estrogen receptor (ER +) and/or the progesterone receptor (PR+). One in eight women in the United States has a chance of being diagnosed with breast cancer and an estimated 250,000 new cases of invasive breast cancer are expected to be diagnosed in 2017.

Standard treatments for ER+ breast cancer are endocrine therapies such as tamoxifen and aromatase inhibitors. “Endocrine therapies are still the most effective medical therapy for this subtype of breast cancer, and the end goal is to inhibit growth and/or kill ER+ breast cancer cells,” said Dr. Irie. ”However, some breast cancer patients still develop metastatic ER+ disease despite these common endocrine therapies, so newer treatments are very important and necessary to kill endocrine therapy-resistant cancers.”

“This is a truly exciting discovery for the field of breast cancer,” said Ramon Parsons, MD, PhD, Director of The Tisch Cancer Institute. “This breakthrough could lead to more effective therapies for women with this very common subtype of breast cancer and be the therapeutic target that the drug companies have been waiting for.”

This work was supported by a Susan G. Komen Career Catalyst Research Grant, as well as Baylor College of Medicine, which made key research contributions.

About the Mount Sinai Health System

Mount Sinai Health System is one of the nation’s leading integrated academic health systems and one of the largest in the New York metropolitan area. The Health System includes approximately 48,000 employees, more than 9,000 physicians, and 8,600 nurses across seven hospitals, more than 400 outpatient practices, over 600 research and clinical laboratories, a school of nursing, and schools of medicine and graduate school of biomedical sciences.  

As a leading learning health system, Mount Sinai combines clinical expertise with scientific discovery to improve patient care while training the next generation of health care and biomedical leaders. The Health System provides care across every stage of life, from prenatal care through geriatrics, while advancing personalized medicine through artificial intelligence, data science, and biomedical research.  

Mount Sinai is consistently recognized among the nation’s leading academic health systems for patient care, research, and education. The Mount Sinai Hospital is ranked No. 1 in New York and recognized as one of the world’s top Smart Hospital by Newsweek. The Icahn School of Medicine at Mount Sinai ranks No. 11 among U.S. medical schools for National Institutes of Health (NIH) funding and No. 1 among freestanding medical schools, reflecting the strength of its scientific enterprise and leadership in biomedical research. 

For more information, visit https://www.mountsinai.org or find Mount Sinai on Facebook, Instagram, LinkedIn, X, and YouTube. To listen to news and stories from Mount Sinai, visit the Mount Sinai Podcast Network.

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