Prostate cancer treatment without the side effects

By piggybacking a chemotherapy drug onto a well-known milk protein, Deakin University medical scientists have created a combination that is lethal for prostate cancer cells without the toxic side effects.

The study, published in the journal Scientific Reports, saw the scientists work with Doxorubicin (Dox) — a chemotherapy drug that doctors have stopped using to treat prostate cancer. As explained by lead author Dr Rupinder Kanwar, “This is because these particular cancer cells are able to flush out the drug and become resistant to it, while the administered Dox continues to kill off the body’s normal cells resulting in a range of side effects, the most damaging of which is heart failure.”

However, the new research suggests it may soon be possible to reintroduce Dox into the treatment regime by coupling it with lactoferrin — an iron-binding protein found in cow milk and human milk.

Lactoferrin is known for its immune-boosting and antimicrobial properties, making it an important part of the body’s protection against infection. Most significantly, it mops up much-needed iron for growth of microbes (bacteria and parasites) from the site of infection and has cancer-killing properties.

Previous work by the team with other types of cancer, funded by the Australia-India Strategic Research Fund (AISRF), found that lactoferrin is not digested by the gut enzymes when fully saturated with iron and given as smart nanocapsules. Building on this work, the team coupled the Dox with lactoferrin, which was fed to a particular breed of mice that naturally develop prostate cancer.

“Rather than being pumped out by the cancer cells, Dox was taken to these cells by lactoferrin through its receptors, which then stays in the nucleus of the cancer cells to perform its lethal action,” said co-author Professor Jagat Kanwar.

“Within 96 hours, all the cancer cells were dead when grown in 3D cancers in a culture dish from drug-resistant and cancer stem cells. In feeding experiments, as an added benefit, there was an increase in red blood cells, white blood cells and haemoglobin, indicating that the immune system had also been boosted.”

Professor Kanwar said the combination “not only targeted the prostate tumour development in mice, it also led to repair of the Dox-induced damage to vital organs, including heart and brain”. The research additionally shows that it is possible for cancer drugs to be taken orally, he said, meaning there may be a time when patients can be treated at home, rather than in hospital.

“Our aim now is to test the cell lines of individual patients,” Dr Kanwar said. “In doing this, we believe it could be possible to use these cells to test the effectiveness, dosage and so on of cancer drugs before they are administered to the patients.”