Scientists from the University of Copenhagen and the University of British Columbia have come across an unexpected benefit from their research into a vaccine against malaria in pregnant women. The researchers have high hopes that their study may prove a possible breakthrough in the fight against cancer, as the armed malaria proteins they worked with were shown to kill cancer cells at a very high rate.
After initial positive animal tests, the researchers are hoping to commence human trials within four years. They published their results in Cancer Cell.
Specifically, the team found that 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. This combination of malaria protein and toxin seeks out the cancer cells, is absorbed, the toxin released inside, and then the cancer cells die.
Professor Ali Salanti said: “For decades, scientists have been searching for similarities between the growth of a placenta and a tumour. The placenta is an organ, which within a few months grows from only few cells into an organ weighing approx. 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.”
His colleague, project leader Mads Daugaard, commented: “We have separated the malaria protein, which attaches itself to the carbohydrate and then added a toxin. 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.”
In collaboration, the two university research groups have tested thousands of samples from brain tumours to leukaemia’s and a general picture emerges to indicate that the malaria protein is able attack more than 90% of all types of tumours.
Professor Salanti concluded: “The earliest possible test scenario is 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. 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.”