Cancer Drug Lessens Severity in Incurable Autoimmune Eye Condition

The incurable autoimmune eye condition uveitis lessened in severity in mice administered a cancer pathway inhibiting drug, a recent study found.

After researchers discovered that the genetic key P-TEFb, which is involved in cancer cell growth, is also involved with immune cells, they decided to test cancer drugs on a uveitis mouse model. The study, published in Cell Reports, revealed the condition was significantly less severe in mice administered cancer drugs.

“Blocking this genetic key, called P-TEFb, prevents the immune system from mobilizing such an aggressive response,” said co-senior study author Richard Jenner. “P-TEFb is important for a lot of cellular processes, and drives uncontrolled growth in cancer cells. A variety of drugs that target this pathway are currently undergoing trials for a range of cancers, and we hope to adapt these to target autoimmune conditions in future.”

The study included whole genome sequencing, which showed that immune cells rely on P-TEFb in order to become specialized T helper cells.

“This work is a great example of how knowledge of the human genome sequence can lead to valuable insights into human diseases,” Jenner said. “It was only by looking across the whole human genome that we were able to identify the function of P-TEFb in the immune system, offering potential new treatments for autoimmune conditions.”

The approach was tested on the uveitis mouse model as a proof of principle, but it should still be able to be used with other autoimmune diseases, Jenner said. However, the cancer drugs used in the study carry too much toxicity for long-term use in the bloodstream, according to the study.

The researchers hope to test more localized approaches for treating uveitis, such as eye drops.

“At the moment, the main treatments for non-infectious uveitis are steroids or the immunosuppressant cyclosporine,” said Virginia Calder, creator of the uveitis mouse model. “Although they can be effective in dampening the inflammation, these drugs can have serious side-effects in the eye including cataract formation and glaucoma. There is therefore a need for localized treatments to tackle the specific immune pathways involved, and this work presents promising new treatment options using existing drugs.”