Generic drug may be potential treatment for deadly brain cancer
Noreen Remtulla & Julia Necheff
A multidisciplinary research team led by Evangelos Michelakis and Kenn Petruk, both professors of medicine in the Faculty of Medicine & Dentistry, has published evidence that the compound dichloroacetate, or DCA, affects the growth of glioblastoma tumours in humans. The findings were published in the May 12 edition of Science Translational Medicine, a journal of the American Association of the Advancement of Science.
Because there is currently no effective treatment for this type of cancer, the results are highly encouraging. “This work is one of the first studies in humans to support the emerging idea of altering the metabolism of tumours as a new direction in the treatment of cancer,” Michelakis said.
DCA is an inexpensive drug that contains dichloroacetic acid, a very small, simple molecule that resembles vinegar. It is mostly used to treat children with a rare metabolic disorder. In 2007, Michelakis and his team published evidence that DCA reverses cancer growth in non-human models. The drug tricks cancer cells into normal energy production by changing the way they handle nutrient fuels. This causes the cancer cells to “commit suicide,” without harming healthy cells.
Many researchers around the world have confirmed the University of Alberta team’s 2007 findings.
Often research that is promising in non-human models does not work outside the lab. However, the U of A team is now reporting success in the next phase of its DCA research, testing the compound in humans.
After extracting glioblastomas from 49 patients over a two-year period, and studying them within minutes of removal in the operating room, the team verified that the tumours responded to DCA.
The researchers then treated five patients with advanced glioblastoma. They obtained tumour tissues before and after DCA therapy. After comparing the two samples, they confirmed DCA worked in the same manner as they had predicted in their earlier test-tube experiments. The unique attribute of DCA is that it alters the metabolism of glioblastoma stem cells, the cells thought to be responsible for the recurrence of cancer.
There were no significant adverse effects. Higher levels of the drug caused some nerve malfunction, such as numbing of the fingers and toes.
The U of A medical research team also found that DCA therapy was most effective when combined with chemotherapy.
What also makes this work significant is the fact it has been largely funded by public generosity. Typically, the pharmaceutical sector funds clinical trials, which are very expensive. However, rights to the DCA compound are not owned by any pharmaceutical company. Michelakis and his team are working to secure more funding to continue their ongoing DCA clinical trials.
The next phase of their research will include a larger number of brain-cancer patients and patients from other academic health science centres. The researchers plan to test DCA in combination with standard chemotherapies. They also wish to expand their research to include breast- and lung-cancer patients.
The U of A research team stresses the limitations of drawing conclusions from five patients. “More clinical trials must be done with DCA,” said Michelakis and that use of DCA as a cancer therapy without close clinical observation by experienced medical teams in monitored research trials is not only inappropriate, but also dangerous.