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Could a tropical sea cucumber hold the key to treating cancer?

Researcher Taitusi Taufa believes chemicals found in invertebrates such as sea cucumbers could potentially be used in future cancer therapies.

A search for new anti-cancer treatments led chemistry specialist Taitusi Taufa to the warm waters of his birthplace in Tonga.

When Taitusi Taufa was an eight-year-old, growing up in Tonga, he accidentally poked a stick into his cousin’s right eye. “Doctors said there was nothing they could do, that he would never see out of that eye,” he says.

But then a traditional healer in a neighbouring village applied drops made from a local plant and within a month, his cousin could see again. “That’s when I realised the healing properties of traditional medicine,” says Taufa, who studied biology and chemistry in Fiji before completing a PhD in chemistry in 2017 at Victoria University, where his research revealed unique anti-cancer properties in marine invertebrates.

It started with his realisation that around 60% of the anti-tumour and anti-infectious drugs used globally are either based on, or inspired by, natural plant-based ingredients. Researching the chemical content of these ingredients led Taufa to the sea – specifically, the warm Tongan waters where he’d grown up.

“Over the past few decades, researchers looking for new natural products with medicinal applications have shifted their focus from land-based sources to the untapped wealth of the marine environment,” he says. “There was an opportunity to explore the marine organisms from Tonga for potential drug discovery.”

During three scuba-diving trips to the Tongan islands – including ‘Eua, which is believed to be one of the oldest islands in the Pacific – Taufa collected samples from marine sponges, sea cucumber and sea squirts. Invertebrates such as these are good sources for new drug discoveries due to their sedentary nature, he says. “They can’t move and lack physical defences like spines or protective shells, which means they’re vulnerable to predators such as fish and turtles. It’s why they’ve developed a suite of defensive chemicals to deter predators.”

A sea cucumber.

It’s these chemicals that Taufa, 36, believes could form the basis of future anti-cancer drugs. “Several of the chemicals showed strong inhibitive activity against certain human cancer cells, which divide more rapidly than most healthy cells. The chemicals from sponges have been shown to disrupt the way cells divide, so they could actually prevent cancer cells from multiplying.”

Medication isolated from sponges could also prove more effective than conventional anti-cancer drugs, because the chemical compounds bind permanently to cancer cells, unlike many current treatments. “That should produce a longer interaction between the cancer cells and chemical compounds, meaning patients would need to take less medication and less frequently.”

Taufa is currently teaching chemistry at the University of the South Pacific in Fiji, alongside his wife Salome, a lecturer in fisheries economics. There’s still much more research to be done before he can test his theory, and many more specimens to be sourced, as each sponge yields only small quantities of the key compounds – but he’s quietly confident the chemicals found in his birthplace could hold the key to a disease that kills around 9.6 million people worldwide every year.

This article was first published in the March 2019 issue of North & South.

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