Precious metal cancer therapy hope  

The University of Edinburgh’s CRUK Edinburgh Centre

New treatment ‘tricks’ cancer cells into admitting rare metal that can be used to target chemotherapy

Monday 9th September 2019

A precious metal used as a key component in motor manufacture, electronics and the oil industry could play a vital role in new cancer therapies.

Researchers have developed a way of dispatching tiny fragments of palladium inside cancerous cells – a metal that scientists have long known could be used to aid cancer treatment but, until now, had been unable to deliver to affected areas.

A molecular shuttle system that targets specific cancer cells has been created by the team at the University of Edinburgh and the Universidad de Zaragoza in Spain.

The new method, which exploits palladium’s ability to accelerate chemical reactions, mimics the process some viruses use to cross cell membranes and spread infection.

Researchers used bubble-like pouches that resemble biological carriers known as exosomes, which can transport essential proteins and genetic material between cells. These exosomes exit and enter cells, dump their content, and influence how the cells behave.

This targeted transport system, that is also exploited by some viruses to spread infection to other cells and tissues, inspired the team to investigate their use as shuttles of therapeutics.

The scientists have now shown that this complex communication network can be hijacked.

The team created exosomes derived from lung cancer cells and cells associated with glioma – a tumour that occurs in the brain and spinal cord – and loaded them with palladium catalysts.

These artificial exosomes act as ‘Trojan horses’, taking the catalysts – which work in tandem with an existing cancer drug – straight to primary tumours and metastatic cells.

Professor Asier Unciti-Broceta, from the University of Edinburgh’s CRUK Edinburgh Centre, said: "We have tricked exosomes naturally released by cancer cells into taking up a metal that will activate chemotherapy drugs just inside the cancer cells, which could leave healthy cells untouched."

The study was funded by the Engineering and Physical Sciences Research Council and the European Research Council.

Having proved the concept in laboratory tests, the academics have now been granted a patent that gives them exclusive rights to trial palladium-based therapies in medicine.

Professor Jesús Santamaría of the Universidad de Zaragoza said: "This has the potential to be a very exciting technology. It could allow us to target the main tumour and metastatic cells, thus reducing the side effects of chemotherapy without compromising the treatment."