Scientists devising new ways to blast cancer

University of Auckland Associate Professor Paul Harris is trying to find a way to nuke cancer cells, without harming healthy cells.

The Health Research Council has just granted $150,000 to Harris and his team of international experts to develop a cancer-beating compound.

The Harris Peptide Laboratory is trying to create a peptide that will act like a Trojan horse, tricking cancer cells into letting boron-10 inside.

A neutron accelerator will then be used to trigger a nuclear reaction as the boron absorbs neutrons. This releases high-energy particles and lithium atoms that obliterate cancer cells, without damaging healthy cells, he says.

Over the past seven years, Harris has been working to develop boron neutron capture therapy (BNCT) that kills cancer without harming healthy cells.

His mother died of bowel cancer when she was 55 years old, then his father died from liver cancer at 73.

“I learned from personal experience how limited cancer treatment options can be.

“It would be amazing to get this technology in New Zealand, so people don’t have to go overseas to get expensive cancer treatments,” he says.

The potential of boron for cancer treatment was discovered in the 1930s and the US Food and Drug Administration (FDA) approved several boron compounds in the 1960s.

However, the existing compounds affect healthy cells, as well as cancer cells, he says.

“The biggest excitement for me is being part of the process of solving that problem, so boron only gets inside the cancer cells and not healthy cells,” says Harris, whose research spans chemistry and biological science.

Nuclear reactors were needed to generate neutrons for early treatments.

Recently, New Zealander Bill Buckley and the US-based company he co-founded, Neutron Therapeutics, developed a neutron accelerator powered by electricity.

“That was a game changer for this treatment,” says Harris.

BNCT is currently used mostly for head and neck cancers. However, Harris hopes it might one day be possible to use neutron beams to destroy other cancers close to the surface, such as melanoma and breast cancer, and possibly even deeper cancers.

The Royal Society Te Apārangi has just granted $80,000 to Dr Renata Kowalczyk, who leads the chemistry research in Harris’ lab, and collaborators from Auckland Cancer Society Research Centre, Dr Peter Choi and Dr Jiney Jose. They are investigating whether BNCT can be used to destroy glioblastoma, which is the most common brain cancer in adults.

Harris’ team includes experts from Australia, Finland, the United States, and the United Kingdom, which has a small-scale neutron accelerator.

“I’m hoping we can use their neutron accelerator to test whether our peptide works to kill cancer cells,” he says.

In 2020, his research received a $1 million kickstart from the Ministry of Business, Innovation and Employment (MBIE). Funding from the University’s Centre for Cancer Research – Te Aka Mātauranga Matepukupuku, and Maurice Wilkins Centre of Excellence followed.

Over the past two years, Harris' biology team led by Dr Jiwon Hong has developed its own lines of cells that express a protein – Alpha v Beta 6 – that is found on the surface of many cancer cells, but is barely seen in healthy cells.

They have created a peptide – a chain of amino acids – that binds to this protein on cancer cells. Now, they are experimenting with different ways to attach boron to the chain.

Peptides are also being made into circular chains, in the hope this will strengthen and disguise them.

“This might stop the peptide from being chopped up by enzymes in the body, before it can carry boron into the cancer cells.”

If tests on lab-grown cancer cells prove effective, the treatment could be tested on ‘organoids’ – three-dimensional versions of human organs that are grown in the lab from human stem cells or tissues.

Harris’ goal is for human clinical trials to launch within ten years.

While it’s an ambitious goal, he has previous experience of being involved in creating a new drug, Trofinetide. Also known as DAYBUE, it was approved by the FDA in 2023 to treat Rett syndrome.

“I wouldn’t do research if it wasn’t exciting,” says the 52-year-old. “And this is exciting, because it has real-world applications.

“Chemotherapy can make people sick, because it attacks healthy cells as well as cancer. This might be another technique to help treat cancer, hopefully with fewer side effects.”