Scientists uncover how 'out-of-breath' cancer cells spread

Professor Ester Hammond and her team at the University of Oxford found that a protein called TPM3 plays a key role in cancer cells adapting to low levels of oxygen. And that this could be a promising treatment target.

The team hope that in the future, this discovery will help researchers develop better, more targeted treatments that stop triple negative breast cancer spreading. 

Triple negative breast cancer accounts for around 15% of breast cancer diagnoses. It can be more aggressive and harder to treat than other types of breast cancer. And there aren’t enough targeted treatments available.

It’s also a type of breast cancer that often contains areas with very low levels of oxygen. This is called ‘Hypoxia’. For healthy cells, hypoxia causes the cells to panic which leads to cell damage or even cell death.

But cancer cells have found a way around this problem. Unlike healthy cells, they can adapt to these low oxygen environments. And this can help them grow, spread and resist treatment. Esther and her team wanted to understand more about how triple negative breast cancer cells do this.

The team studied a protein called TMP3. TPM3 is important as it helps cells control their shape, the way they move and how they interact with other cells around them.

They found that TPM3 levels were higher in cancer cells than in healthy cells. And that high levels of this protein are linked to worse outcomes in triple negative breast cancer.

Ester and her team then ran a series of experiments on triple negative breast cancer cells grown in the lab at different oxygen levels. And they found an interesting link.

As the oxygen levels decreased, the amount of TPM3 produced by the cells increased. This response was controlled by another, oxygen-sensing protein called HIF-1.

When they blocked TPM3 from working as it usually would, the triple negative breast cancer cells changed shape and were less able to move and spread around the body. And importantly, when they combined this with chemotherapy treatments, it made these drugs more effective.

The researchers also found that the cancer cells were able to wrap up TPM3 into tiny packages that could be released and delivered to cancer cells growing in normal oxygen environments.

Through these findings, our scientists have shown how TPM3 links low oxygen levels and cancer cells spreading. Making it a promising target for new treatments. 

This news is especially promising for people like Danielle , a teaching assistant and mother of two from Oxford. Danielle was 17 weeks pregnant with her second child when she first felt a small lump in her left breast.

At first, she wasn’t overly concerned. But her mum and sister encouraged her to get it checked out for peace of mind. A week later, Danielle was called back to the hospital where she was given the devastating news that she had triple negative breast cancer.

Thankfully, Danielle is now 8 years cancer-free. And her experience has left her with a deep belief in the power of research and progress.

Every year around 8000 people in the UK are diagnosed with triple negative breast cancer. That’s 8000 people that need better treatments.

The findings from Ester and her team are early research, but it's another step forward in developing new, targeted therapies for this type of breast cancer.

Other researchers have already developed drugs that target TPM3, showing that it’s possible. Now, this discovery could drive future interest and investment to further study this protein and create new a treatment for triple negative breast cancer.

This research was funded by us and supported by UKRI and the Saturday Hospital Fund