Scientists find new cancer-killing compound in sea snail goo
The natural world is a huge source of important medicines, and among all the species that scientists turn to for inspiration the humble snail continues to provide the goods. New and improved insulins and painkillers are a couple of possibilities these mollusks have put forward, and researchers have uncovered yet another in the form of an anti-cancer compound sourced from the glands of an Australian sea snail.
The research was led by scientists from Australia’s Flinders University, Southern Cross University and Monash University, who were investigating the makeup of anti-bacterial substances the white rock sea snail secretes onto its eggs to protect them from the bacteria-rich marine environment.
These properties led the scientists to suspect the purple goo might contain compounds that could also take the fight to cancer. They conducted experiments exposing extracts of the substance to human cancer cell lines and found that they did indeed bring about their death, prompting further investigations to try and understand how.
“We were able to go into a long-term colorectal cancer model,” Catherine Abbott, professor of molecular biology at Flinders University and study author, explains to New Atlas. “This meant we were able to show that one of the compounds in the extract, 6-Br, was able to reduce tumors. Before this we had only looked at their effects, six hours after DNA damage had been caused to a colon cell.”
These longer term observations of the compound’s activity were then corroborated and probed further through an advanced form of mass spectrometry. This allowed the scientists to actually track how the compound 6-Br moved through a mouse model toward the tumors after being administered orally.
“We are able to show that 6-Br and its metabolites are present in the GI tract and are delivered to the colon where the tumors are formed,” Abbott tells us. “The breakthrough here is demonstrating that this specialized mass spectrometry technique can be used to trace the fate of an orally administered drug from the stomach to the feces.”
One convenient byproduct of this approach is an ability to keep an eye out for metabolites that could produce toxic side effects. The team tested out a couple of versions of the compound and the technique is already helping them work out the most promising pathways forward.
"We treated animals with synthetic 6-Br and crude extract containing natural 6-Br,” Abbott explains. “We believe the toxic metabolites are coming from another compound found in the extract, thus they were not observed when we used the synthetic 6-br compound alone. The metabolites of this 6-br do not appear to be toxic, so synthetic is a great lead compound for further development.”
There are parallels between this research and another project we covered back in 2016, where scientists at Australia’s University of Wollongong identified a new class of molecules in the eggs of sea snails that proved particularly potent against cancer cells that had grown resistant to chemotherapy drugs.
As with that research, there is a long way to go before this compound is translated into anti-cancer drugs for clinical use, but the early results are promising. Colorectal cancer is the second-leading cause of cancer-related mortality, with 862,000 deaths in 2018, according to the World Health Organization. So any new tools in the fight would be very welcome indeed.
"We're very excited about these latest results and hope to attract investment from a pharmaceutical company to work on a new drug to reduce development of colorectal cancer tumours,” says Abbott.
The team has published its research in the journal Scientific Reports.