New Gene Therapy Shows Promising Results

Research lead by Stephanos Kyrkanides, D.D.S., Ph.D., associate professor of Dentistry at the University of Rochester Medical Center shows that a new gene therapy can nearly eliminate arthritis pain, and significantly reduce long-term damage to the affected joints. This study was published in the June 2007 issue of Arthritis and Rheumatism.

Current treatment of arthritis is dominated by drug treatments like non-steroidal, anti-inflammatory drugs, COX-2 inhibitors and acetominophen. Gene therapy has been attempted in the past, but older, invasive techniques required that therapeutic genes be injected directly into nerve cells. This caused nerve damage in many cases.

A different approach was taken in this study. Using lab mice, opiod receptors, proteins built into the outer surfaces of cells that react specifically to opiates and opiate-related substances, on nerve cells involved in carrying pain messages between an osteoarthritic jaw joint and the spinal cord were increased by about one thousand times the normal amount. With this drastic increase in receptors, the nerve cells involved in pain transmission responded much more strongly painkillers, naturally occurring and otherwise.

The number of receptors was increased via tailor-made genes into cells that can, for instance, direct cells to build more of a needed protein. To deliver the genes into cells, researchers use harmless viruses called vectors, which have evolved to invade the defenses of the human cells and insert their own DNA. In designing the new therapy, Kyrkanides' team chose to work first with vectors based on feline immunodeficiency virus (FIV), a lentivirus that attacks the immune system of cats.

Despite the strong results, however, the team will seek to deliver the same gene therapy with a different vector called adeno-associated vector (AAV) in the next phase of experiments. This is because AAVs have already been approved as safe for experimental gene therapy by the U.S. Food and Drug Administration. If successful, this next study will provide the proof of principle needed for the team to apply for phase I human clinical trials within a few years.

Article References
Arthritis Pain 'Abolished' And Joint Damage Reduced With Experimental Gene Therapy, site accessed on 6/4/2007