Breast Cancer Awareness Month: Engineering bacteria to fight breast cancer

Almost 3,000 women are diagnosed with breast cancer every year in Wales. While survival rates continue to improve thanks to advances in diagnosis and treatment, breast cancer remains one of the leading causes of cancer-related death, claiming around 600 lives in Wales each year.

To help change these statistics, Cancer Research Wales is funding pioneering research at Cardiff University led by Dr Lee Parry, in collaboration with Prof Paul Dyson at Swansea University, to explore an exciting new way to target breast cancer using engineered bacteria.

The team is building on their previous laboratory research that has demonstrated how specially engineered bacteria can be safely used to deliver treatments directly to breast cancer cells, right in the heart of the tumour. By specifically targeting cancer cells and saving healthy tissue, treatment side effects can be reduced. Their research focuses on S. typhimurium, a bacterial species with the ability to enter tumour cells, making them ideal vehicles for delivering targeted therapies.

Delivering targeted treatments

This approach offers a powerful double benefit: the bacteria can deliver targeted treatments whilst also stimulating the immune system to recognise and attack the tumour. Importantly, the bacteria can be safely controlled using antibiotics.

Previous research from the laboratory has successfully used this platform to target c-MYC, a gene that drives cancer growth, with promising results. The team is now looking to target PD-L1, a molecule that helps cancer cells evade the immune system. PD-L1 is currently targeted using the drug Atezolizumab, which prolongs survival in breast cancer patients but suffers from adverse side effects. By blocking PD-L1 only in the tumour using bacteria, the researchers hope to make tumour cells more visible to the body's natural defences without the adverse side effects.

Ultimately, the team aims to combine c-MYC and PD-L1 targeting therapies, creating a more powerful and effective treatment for breast cancer, with the potential to simultaneously target cells which have spread around the body.

A new form of gene therapy

Following successful pre-clinical studies, the next steps will involve additional safety testing and regulatory approvals to progress towards clinical trials. Ultimately, the researchers hope to advance the technology through the Advanced Therapy Medicinal Product (ATMP) pathway, bringing this promising new form of gene therapy closer to use in patients in Wales.

If successful, this innovative approach could lead to more precise and effective treatments for breast cancer patients in Wales. The platform can also be adapted to target other cancer types, expanding its benefits to more patients in the future.