In the hunt for a vaccine against malaria in pregnant women, scientists have discovered that malaria proteins can be used to attack the majority of tumour types.
So far, trials have only been conducted on mice. Researchers aim to begin human trials within four years.
Scientists from the University of Copenhagen and the University of British Columbia were researching a vaccine to fight malaria in pregnant women when they discovered that armed malaria proteins can kill cancer.
The carbohydrate that the malaria parasite attaches itself to in the placenta in pregnant women is identical to a carbohydrate found in cancer cells.
In the laboratory, scientists have created the protein that the malaria parasite uses to adhere to the placenta and added a toxin.
The malaria protein and toxin combination seeks out the cancer cells and is absorbed. The toxin is released inside the cancer cells and then kills them.
This process has been witnessed in cell cultures and in mice with cancer.
“For decades, scientists have been searching for similarities between the growth of a placenta and a tumour," said Professor Salanti from the Department of Immunology and Microbiology at the University of Copenhagen.
"The placenta is an organ, which within a few months grows from only few cells into an organ weighing approximately two pounds, and it provides the embryo with oxygen and nourishment in a relatively foreign environment.
"In a manner of speaking, tumours do much the same, they grow aggressively in a relatively foreign environment.
"We examined the carbohydrate’s function. In the placenta, it helps ensure fast growth. Our experiments showed that it was the same in cancer tumours. We combined the malaria parasite with cancer cells and the parasite reacted to the cancer cells as if they were a placenta and attached itself."
The University of Copenhagen collaborated with researchers from the University of British Columbia to test thousands of samples from brain tumours to leukemias.
They believe the malaria protein is able to attack more than 90% of all types of tumours.
The drug has been tested on mice that were implanted with three types of human tumours.
With non-Hodgkin’s lymphoma, the treated mice’s tumours were about a quarter the size of the tumours in the control group.
With prostate cancer, the tumours disappeared in two of the six treated mice a month after receiving the first dose.
With metastatic bone cancer, five out of six of the treated mice were alive after almost eight weeks, compared to none of the mice in a control group.
"We have separated the malaria protein, which attaches itself to the carbohydrate and then added a toxin," said Mads Daugaard, who is head of the Laboratory of Molecular Pathology at the Vancouver Prostate Center at UBC in Canada.
"By conducting tests on mice, we have been able to show that the combination of protein and toxin kill the cancer cells.
"It appears that the malaria protein attaches itself to the tumour without any significant attachment to other tissue. And the mice that were given doses of protein and toxin showed far higher survival rates than the untreated mice.
"We have seen that three doses can arrest growth in a tumour and even make it shrink,” addded PhD student Thomas Mandel Clausen.
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Unfortunately, the treatment would not be available for pregnant women.
"The toxin will believe that the placenta is a tumour and kill it, in exactly the same way it will believe that a tumour is a placenta," said Professor Salanti.
The University of Copenhagen has now created the biotech company, VAR2pharmaceuticals, which will drive the clinical development forward. They aim to conduct tests on humans in four years time.
"The biggest questions are whether it’ll work in the human body, and if the human body can tolerate the doses needed without developing side effects," said Professor Salanti.
"But we’re optimistic because the protein appears to only attach itself to a carbohydrate that is only found in the placenta and in cancer tumours in humans."