Rongoā is the Māori term for medicines produced from native flora and fauna. Rongoā are still used extensively today, and resources are carefully collected in a sustainable manner. But what happens when the potential medicine comes from a rare, endemic sea sponge that grows deep in the ocean off Fiordland? Hemi Cumming and his colleagues Peter Northcote and Paul Teesdale-Spittle are investigating.
Biodiscovery and marine sponges
Biodiscovery – finding chemicals within organisms that may have benefits for humans – is a high-risk high-reward research area. It is extremely expensive and takes years of research to create a new drug, but the financial and social pay-offs can be enormous.
Sea sponges are of particular interest to researchers. They have soft bodies and cannot move so they produce toxins to defend themselves. The marine sponge Mycale hentscheli produces several cytotoxins – substances that have toxic effects on certain cells – and have potential as cancer treatments. Peloruside A and B and pateamine are compounds that New Zealand scientists have isolated and are trying to develop as anti-cancer drugs.
One of the challenges for this research is getting enough sea sponges. The endemic Mycale hentscheli sponges are reasonably common, but only certain populations produce peloruside A and pateamine, so harvesting wild populations is not sustainable. Scientists either need to ‘farm’ the sea sponges or make the compounds in a laboratory. Both methods have their difficulties. Aquaculture trials were hampered by hungry sea slugs, and it can be difficult to synthesise complex chemical compounds found in nature.
Perhaps somewhere deep underwater or in the heart of the ngahere lie natural solutions to some of humanity’s most pressing problems.Dr Ocean Mercier
Creating a simplified version of pateamine
Due to the scarcity of natural pateamine sources, Hemi Cumming is attempting to create a mimic of the natural compound. First, Hemi and his colleagues have to work out the compound’s complex chemical structure. Then they have to make it using simple chemical building blocks to recreate the large and chemically complex pateamine compound. To be commercially successful, the pateamine mimic must be able to be mass-produced and be able to reduce (inhibit) protein production in cancerous cells.
Dr Peter Northcote says, “Synthesis is more than just a science. You need to have the creativity to see new ways of making these compounds, and you also need to have persistence because you may get nine-tenths of the way only to find an unachievable target and then you have to go back and try a different way to get to the same place.”
Nature of science
Hemi’s challenge to successfully synthesise a pateamine mimic demonstrates the difficult nature of some scientific investigations. His research requires the 3 Ps – problem solving, persistence and patience.
Hemi has been able to make two of the key connections work, but the final connection is proving difficult. He says, “It’s a challenge, but you just have to be persistent and be quite determined because of the ultimate outcome and benefit that it potentially could have.”
For Hemi and the team, the drive to create an anti-cancer drug goes beyond the financial benefits. Most families have felt the effects of cancer – being able to find a treatment is an awesome goal.
Biodiversity and biodiscovery
Many of Aotearoa’s species are endemic – they are found nowhere else on Earth. More than 10% of our marine species can generate biological chemicals that have potential for biodiscovery. Hemi’s research is a medical example but natural marine chemicals can also be used to create agricultural pesticides and more.
Protecting our biodiversity, researching how various species survive and working out how these abilities might help people will support an innovative economy.
The video Cawthron Institute – Selling Purified Marine Toxins highlights a high-risk-high reward success story. Cawthron Institute landed a lucrative deal to supply a range of purified marine toxins at $5,000 per milligram!
Getting a new drug to market
Diabetes affects millions of people worldwide. The New Zealand company Living Cell Technologies is developing pig cell transplants to treat diabetes and other diseases. The articles Pig cell transplants, Diabetes and pig cell transplants and Trialling pig cell transplants highlight the research and development processes associated with getting new drugs to market.
Natural toxins have the potential to be a valuable tool for medical and agricultural researchers. The activity Detecting toxins explains some of the processes used by toxicologists.
Rebecca Priestley discusses sea sponge cytotoxins and their potential benefits in the New Zealand Listener article: Are marine sponges going to cure cancer?
Hemi’s story on the Victoria University of Wellington website provides background information about Hemi’s PhD research and his route to becoming a scientist.
Watch Series 2/Episode 9: Sea Sponge: A Cancer Treatment from Tangaroa
Project Mātauranga is a television series that investigates Māori world views and methodologies within the scientific community and looks at their practical applications. Each of the 13 episodes in series 2 shows how western science and Māori knowledge systems are combining to provide solutions to a variety of challenges.
The Science Learning Hub thanks Scottie Productions for allowing us to host these videos.