Cancer patients usually undergo radiation therapy. The article explains that in the cases of head and neck cancer, the radiation therapy affects the patient’s salivary flow, this causing dry mouth. Doctors have been searching for new drugs and other kinds of treatments that might help restore adequate salivary flow in patients under radiation therapy secondary to head and neck cancer. These people’s salivary glands had been damaged by radiation treatment as the radiation causes as much damage to healthy salivary glands and tumor cells. By the late 1980s doctors turned their attention to gene transfer. The treatment is also sometimes called gene therapy.  The concept behind this therapy relies on transferring a fluid-transporting gene into the damaged salivary glands of the patient that can be clearly seen under usb-microscope. Resaerchers and doctors believe so that it could potentially restore some degree of salivary flow and secretion into the mouth. The problem they faced however was how to deliver a gene into a salivary gland. The doctors found that the process might be possible to put a gene and its viral vector into a syringe and infuse them directly into the gland through its opening in the mouth.

The doctors describe in the article about their treatment. They claim that the gene transfer that they have developed builds on the fundamental fact that the ducts are water impermeable in the irradiated glands. With the process of gene transfer, the ducts will have the potential to move fluid and secrete it into the mouth. The doctors explain that it operates by the law of osmosis. They further explain that water naturally follows an osmotic energy gradient, flowing from areas of low to high salt concentration. Doctors that study this new treatment believe the irradiated duct cells can generate such an osmotic gradient. Doctors have worked with scientists in the last decades in order to determine whether transferring a gene into the cells that line the ducts can take advantage of the ability of these cells to generate an osmotic gradient and secrete saliva into the mouth. For a clearer view, this can be seen under a usb-microscope. The doctors explain that the specific gene to be involved in the gene transfer treatment is the Aquaporin 1.  The said gene encodes a large protein that transports fluid by forming pores, or water channels, in the cell membrane.  The doctors hope that the transferred gene will produce reasonable levels of the aquaporin 1 protein in duct cells. They believe it will set in motion a therapeutic domino effect where the aquaporin 1 protein will open up water channels in the duct cells.  It will then allow the very rapid movement of water through the duct in response to the osmotic gradient that we believe can be generated. The gene is contained in a vector in order to deliver aquaporin 1 to its target.  The vector in the treatment is an adenovirus.  The article explains that it is a common respiratory virus that has been used in gene transfer studies for many years.  The doctors however clarified that the said virus has been modified and would not make a person sick. Read more