Potential cancer treatment found in weird place
QUEENSLAND scientists studying a tapeworm commonly found in dogs have stumbled upon a potential new treatment for some human cancers.
In what they describe as scientific serendipity, the QIMR Berghofer Medical Research Institute scientists have found that a protein secreted by the Echinococcus granulosus tapeworm prevents melanoma and breast cancers from spreading in mice.
But they need more research funding to further study the protein, known as EgKI-1, as a possible new cancer therapy.
The tapeworm causes a disease known as echinococcosis in humans, leading to the development of cysts in a person's liver, lungs and other organs. Most cases occur in Asia and Africa, but the parasite is also present in Australia with, on average, 10 diagnoses of echinococcosis per year in rural Queensland.
The QIMR Berghofer researchers, including Professor Don McManus, the head of the institute's molecular parasitology group, were hoping to develop a echinococcosis vaccine by studying how the parasite, in its larval stage, infiltrates the human gut and gets into the bloodstream.
What they discovered has instead redirected their research towards probing EgKI-1 for its potential cancer-fighting properties.
Studying the protein in the laboratory, they found it inhibits an enzyme, known as neutrophil elastase, produced by white blood cells.
"Because we knew that cancer cells also produce large quantities of these neutrophil elastase enzymes, we decided to explore if the EgKI-1 protein would also kill cancer cells, which it did," said Dr Shiwanthi Ranasinghe, the primary investigator.
"That was the Eureka moment."
Dr Ranasinghe said EgKI-1 had killed melanoma, breast and head and neck cancer cells in the test tube with no effect on healthy cells and they hoped to do further research on whether it worked against other types of cancer.
Their ultimate aim would be to develop EgKI-1 into an experimental cancer treatment that could be tested in human trials.
That possibility is years away with much more work needed into how the protein works as an anti-cancer agent. Further animal trials would be necessary before studies in humans.
"It's promising but there's a lot more work that we need to do before we can consider taking it to a clinical trial setting," Professor McManus said.
"The original idea we had was we wanted to find a molecule that the parasite produces that protects itself against the host, which is what we discovered. But we found this same molecule is an anti-cancer agent, which is really quite profound. It's serendipity."
The research is published in the online journal, Scientific Reports.