Molecule in the nervous system may hold key to treating chronic pain

By analysing a large number of genes important in the transmission of pain information to the brain, principal investigator Dr. Christophe Altier, PhD, who holds a Canada Research Chair in Inflammatory Pain, and his team have identified the existence of a molecule in the nervous system that enhances sensitivity to pain.

This molecule had previously been thought to play a role in cancer growth but had never been reported in the nervous system. It may now be possible to use already existing anti-cancer drugs to block pain.

"The most exciting part of this discovery is that we don't need to develop a new drug," says Dr. Christophe Altier, PhD, associate professor at the Cumming School of Medicine (CSM) and member of the Snyder Institute for Chronic Diseases at the CSM. "We've shown that an existing drug, approved in the treatment of cancer, can be repurposed to treat pain."

In the study on mice, Altier's team showed drugs commonly used for treating lung cancer and a type of brain cancer could be effective in controlling pain. The researchers specifically tested for pain resulting from nerve injury and inflammation and found the cancer drugs worked very well. The next step is to secure funding for clinical trials to see whether the same positive results will be experienced by people suffering from chronic conditions including abdominal pain and post surgery pain.

Because the drugs being used already exist and have been proven safe, the timeline for this treatment to become a reality will be shorter than if they had to develop new medications. Altier has already filed a patent application for this novel treatment with study co-author Dr. Gerald Zamponi, PhD, professor at the CSM and member of the Hotchkiss Brain Institute.

The discovery will be welcome news for chronic pain sufferers who in the future might have the option to stop taking potentially addictive opioids that require increases in doses over time to remain effective.

"With these anti-cancer drugs, there is no effect on tolerance," says Dr. Manon Defaye, PhD, first author on the paper. "We don't need to increase the dose of the drug to obtain pain relief."

Funding for this research came from the Canadian Institutes of Health Research and the Alberta Children's Hospital Research Institute.