Gene Therapy: On the Cutting-Edge
Gene therapy is a cutting-edge technique, which through recent advances has moved from theoretical fantasy into a potential medical therapy. It is also a powerful research and educational tool that will open the doors to a greater understanding of spinal problems. It is hoped that gene therapy will lead to the development of therapeutic treatments that could potentially solve all the problems we see in the spine.
Gene Therapy Trials
Since 1990, there have been over 300 human gene therapy trials with well over 3000 patients enrolled, and this number is steadily growing. For terminal systemic disorders such as paralysis or Parkinson's Disease, gene therapy has had limited success; however for localized conditions such as spinal fusion or disc regeneration, gene therapy can be a very powerful and successful tool.
In general, gene therapy is the transfer of genetic information into cells and tissues to achieve some desired effect. In humans, gene therapy is typically used to treat or compensate for a genetic mutation in the cellular genetic machinery or to enhance the production of a certain protein. Using gene therapy to treat systemic conditions has been quite difficult because it requires the transformation of large areas of human tissue in the body that need to last the lifetime of the patient. For the treatment of spinal disorders however, we only need to transfer the genes to small portions of the spinal tissues and this only needs to last for a short period of time (such as for spinal fusion). Gene therapy for spinal fusion, for example, would not require that the gene be expressed or active for the life of the patient but rather only for a short period of time such as days to weeks or long enough to achieve successful fusion.
Five Basic Steps
The use of gene therapy has five basic steps, and there are a variety of methods to achieve each step.
· Step 1: The gene coding for the desired protein is isolated.
· Step 2: The gene is delivered to a target cell by means of a vector. This vector carries the gene and gets it into the cell.
· Step 3: The cell integrates this gene and begins to produce DNA and RNA coding for the protein.
· Step 4: The protein is made by the cell.
· Step 5: This protein acts inside the cell or is released into the environment and then stimulates the desired action such as spinal fusion or disc regeneration.
Gene Therapy and Spinal Fusion
Spinal fusion is an excellent example of how gene therapy could revolutionize spinal surgery. Instead of putting a protein into the spine to stimulate fusion, surgeons would instead transfer the gene that codes for that protein into a portion of the spinal tissues, allowing those tissues to produce the protein responsible for bone growth. Although this seems like a complex procedure, it is much less invasive than current spinal fusion methods, which require an open incision, a certain amount of blood loss, pain to the patient and a significant period of healing. Gene therapy has the ability to dramatically change how this surgical procedure is performed. Imagine replacing an open spinal fusion surgery along with the required general anesthesia, risk of significant blood loss, pain, and prolonged recovery time, into a less invasive, one-injection procedure given on an outpatient basis without the need for a hospital stay. Although it may seem like a theoretical fantasy, in actuality there is a huge potential for the use of gene therapy in the treatment of spinal disorders.
Opening the Doors to Discovery
The main reasons for using gene therapy to treat spinal disorders would be to provide more efficient and effective ways of achieving important medical needs such as spinal fusion, disc repair or regeneration, or even regrowth of spinal cord and nerve cells. Currently we do not have answers for many of these problems; however, gene therapy can give us the methodology by which these could be potentially achieved. Studies are proving the process to be very safe and may become available in 4-5 years.
Gene therapy is still in the experimental stage and is not yet available for the treatment of spinal disorders in humans. There have been many animal studies that prove gene therapy strategies to be effective and viable techniques for achieving spinal fusion and potentially disc regeneration. In the future, the use of gene therapy will allow us to achieve better, faster and more effective spinal fusions than we can today with grafts, growth factors or proteins. Further down the line, it is likely that gene therapy will be used to accomplish disc regeneration, disc repair, spinal cord repair or even regeneration of damaged nerves.
Although not yet approved for spinal disorders in humans, gene therapy techniques will open the doors for the discovery of new and more effective therapeutics as well as allow us to accomplish treatments that today we can only imagine.