Researchers find new approach to treat drug-resistant HER2-positive breast cancer

CHAPEL HILL, NC – Resistance to therapy is a major problem in the cancer field. Even when a treatment initially works, the tumors often find ways around the therapy. Using human cell lines of the HER2-positive breast cancer subtype, researchers from the UNC School of Medicine and UNC Lineberger Comprehensive Cancer Center have detailed the surprising ways in which resistance manifests and how to defeat it before it happens.The discovery, published today in the journal CELL Reports, provides the experimental evidence for the potential development of a novel combination therapy for HER2-positive breast cancer. The combination includes the FDA approved drug lapatinib and a new experimental drug called a BET bromodomain inhibitor, which works by disrupting the expression of specific genes.

This study, a collaboration of 20 University of North Carolina researchers, is the first time a BET bromodomain inhibitor has been shown to prevent the onset of resistance to drugs such as lapatinib in breast cancer cells.

“This research was done in cell lines of human HER2-positive breast cancer, not in patients; but the results are very striking,” said Gary Johnson, PhD, Kenan Distinguished Professor and chair of the department of pharmacology, member of the UNC Lineberger Comprehensive Cancer Center, and senior author of the paper. “The combination treatments are currently being tested in different mouse models of breast cancer. Our goal is to create a new kind of therapy that could help oncologists make the response to treatment more durable and lasting for breast cancer patients.” (excerpt from UNC School of Medicine News article by Mark Derewicz published April l9, 2015, link to full article is provided below).

Tim Stuhlmiller, PhD, a postdoctoral fellow in Johnson’s lab is first author on the paper.

Read the full article by Mark Derewicz on UNC School of Medicine News.