A strange organism living in the icy waters of Antarctica could hold the key to curing melanoma skin cancer.
A team from the University of South Florida (USF) has returned from a six-week expedition to one of the most remote regions on Earth to study a species of ascidian, commonly known as a sea squirt, which contains a bacterium capable of killing melanoma cancer cells.
USF chemistry professor Bill Baker’s research has identified the organism’s potential cancer-fighting properties.
He is now helping to lead a US National Science Foundation-supported project aimed at understanding the compound in greater detail and assessing whether it could one day contribute to new treatments for melanoma patients.
Professor Baker said: ‘We first discovered this ascidian produces a bacterium that contains a toxic compound that kills melanoma cancer cells while not harming normal human cells.
Sign up for all of the latest stories
Start your day informed with Metro’s News Updates newsletter or get Breaking News alerts the moment it happens.
‘That selectivity is critical in drug development because you want to treat the disease without harming the patient.’
For decades, Professor Baker has travelled to Antarctica to study marine organisms that may have pharmaceutical applications.
Previous discoveries by his team have led to patented compounds with potential uses in tackling diseases including drug-resistant malaria, cancer and antibiotic-resistant infections.
Researchers say Antarctica offers a unique natural laboratory because of its long geographical and environmental isolation.
Professor Baker added: ‘The continent is unique because it has been geographically and environmentally isolated for millions of years.
‘As a result, species in Antarctica have had time to evolve independently, leading to highly specialized organisms. The ascidians we study are adapted specifically to this environment and are not found anywhere else.’
While Professor Baker advised the 2026 expedition from the United States, USF diving safety officer Ben Meister and postdoctoral researcher Sam Afoullouss represented the university on the Antarctic mission.
Afoullouss said: ‘Our expedition focused on determining where the ascidian’s melanoma-killing bacterium occurs and how widespread it is.
‘We also wanted to understand how it lives inside the organism and how that connects to the compounds linked to melanoma research.’
The ascidians studied during the expedition are typically found at depths of between 60 and 80ft, often attached to steep or vertical surfaces on the seafloor where strong currents provide a steady supply of nutrients.
Collecting the specimens required multiple dives as well as the deployment of remotely operated vehicles to investigate deeper waters and identify new collection sites along the Antarctic Peninsula.
Mr Meister said: ‘On average, our dives were about 25 to 35 minutes at a time with a maximum of 130 feet.
‘But in Antarctica, you’re dealing with ice, leopard seals, changing seas and sometimes very limited visibility.
‘Every dive must be carefully planned to balance getting the work done while keeping everyone safe.’
Scientists say careful planning is essential not only for diver safety but also to ensure samples are collected and preserved correctly for laboratory analysis.
Maintaining the integrity of the specimens is considered crucial because even minor changes could affect understanding of how the compounds function.
Now that the expedition has concluded, researchers say the most important phase of the work is beginning.
Specimens collected during the mission will be analysed by multiple teams specialising in genetics, chemistry and biology.
The process is expected to take months, and potentially years, as scientists seek to understand the compounds and their possible medical applications.
Professor Baker said: ‘This research is important both environmentally and medically.
‘We are learning how organisms use symbiosis to survive in extreme conditions, which is still largely unknown in cold-water ecosystems like Antarctica.
‘Understanding the source and function of this compound is critical if we hope to develop it into a drug.’
Researchers say discoveries such as these represent the earliest stages of a lengthy scientific process, but could eventually help identify a cure for melanomas, as well as other complex diseases.