Studying the role of cancer stem cells in oestrogen receptor positive breast cancer

Most types of breast cancer are unlikely to come back more than 5 years after treatment. But oestrogen receptor positive (ER-positive) breast cancers can return many years, even decades, later.

This often happens because a small group of cancer cells, called cancer stem cells, can survive treatments and cause the cancer to return. If we can get rid of these cancer cells with more effective treatments, we could help more people to live with and beyond breast cancer.

Professor Axel Behrens’s team found a rare type of cell in the breast tissue of mice. These cells developed into ER-positive breast cancer, but only when they experienced specific changes. The cells had a protein on their surface, called Lgr6, which is how researchers could tell them apart. 

Breast tumours grew much slower in mice when these cells weren’t there. It suggests that the cells with the Lgr6 protein are cancer stem cells, and tumours need them to grow quickly. 

In previous work, Axel and his team also found that these cells play a key role in how breast cancer resists chemotherapy and spreads to other organs. Now, they want to further study them to ultimately develop new targeted therapies.

Axel and his team are focusing on 2 projects:

1. Studying the role of cancer stem cells in ER-positive breast cancer

   Cancer cells with the Lgr6 protein cluster together within a tumour. This suggests that other cells in their environment support their growth. Axel wants to identify and better understand these supporting cells, to find new treatment targets.  

   The team is also looking at how these cancer stem cells help ER-positive disease spread to and grow in the lungs, and how they help to resist treatment. Using advanced techniques, they’re studying how tumour cells interact with non-cancer cells during treatment. Their goal is to understand how breast cancer can survive treatment and grow back. 
   
   

2. Developing better ways to study ER-positive breast cancer

   We still need better ways to study breast cancer in the lab that reflect how the disease emerges and changes in people. One way is to grow 3D mini tumours, also called organoids, in the lab. Axel’s team have successfully grown these mini tumours using tissue samples donated by people with ER-positive breast cancer.

   Now, they’re studying the different cells in ER-positive breast cancer and how different cancers respond to common treatments like tamoxifen. They want to understand why cancer treatments work in some people but not in others, and why some breast cancers return. They’re also looking for weak spots that could be targeted with new therapies.

Axel hopes that this work will make a real difference for people with ER-positive breast cancer. If we can better understand the cancer cells that make the disease resistant to treatment, we’ll then be able to target them. This could result in more effective treatments.  

Thousands. Around 55,000 women are diagnosed with breast cancer every year in the UK, and around 80% of these cancers are ER-positive.