Ha'aretz, October 23, 2002 A Speedy Recovery Is Not Always Best By Tamara Traubmann In recent years, a small group of scientists has begun to focus on a new area in medicine: regenerative medicine. The field presumes to restore tissues and organs that deteriorate with the aging process. Proponents of this field strive not only to halt the degenerative processes that cause diseases like cardiac insufficiency, but also to restore damaged tissues like new. Traditionally, biologists trying to develop a new drug searched for a single molecule to treat a specific disease. Despite countless studies and some breakthroughs, diseases such as Alzheimer's, Parkinson's, and renal insufficiency have remained incurable. Proponents of regenerative medicine have adopted a more general approach. They are attempting to decipher the methods of communication between the cells that comprise body tissue to understand and mimic them when treating damaged tissue. The tools used in regenerative medicine are stem cells and other healthy body cells, whose increased activity is required to cure disease, as well as the chemical signals artificially transmitted to them when simulating communication between healthy cells. One of the milestones in this area of research is the discovery that a similar mechanism, linked to the method of scar formation, is fundamental to a wide variety of diseases. The major problem with scar tissue is the fact that scars are central to the process behind diseases such as cardiac insufficiency and renal insufficiency. In response to organ damage, the body attempts to quickly repair the affected tissue, forming a scar at the site. The problem is that the scar has a different structure than the original tissue. Instead of healing the organ, the scar causes a deformity, preventing it from functioning normally. In the case of the heart, for example, instead of cardiac muscle tissue contracting with amazing power and coordination, a scar is formed, which prevents the heart from functioning like a pump. The result is insufficiency. A circuit breaker A number of years ago, researchers at the Volcani Institute in Rehovot, under the direction of Dr. Mark Pines, discovered a substance known as Tempostatin™, which is capable of delaying scar tissue formation. This substance interferes with the chemical communication between the cells responsible for tissue repair. It affects stroma cells - cells that support body tissue, produce collagen and play a central role in the repair of damaged tissue. Collagen generally supports cells and assists them with the formation of new tissue. However, after an injury, collagen is produced in such large quantities that they actually prevent the tissue from being rebuilt normally. "Tempostatin™ is actually the `circuit breaker' of the scar formation process," says Dr. Bruce Bach, CEO of the U.S.-Israeli biotechnology company Collgard, which is currently developing the substance. Its method of activity is, to a certain extent, paradoxical. "It slows down the healing process, thus improving the results of the tissue's response to injury," claims Bach. According to him, "By allowing the healing process to occur at a slightly slower pace, the likelihood that the body itself will treat the damage properly is increased. Tempostatin™ regulates the process that determines whether the body begins the damage repair response. Slowing down the activity of the stroma cells results in a gradual growth of tissue and much better results." The agent has been tested for safety in patient populations and has been judged acceptable for use in controlled clinical trials, but its effectiveness has so far been proved only in animals. It is currently being tested in clinical trials being conducted at medical centers in Europe. Animal studies have shown that Tempostatin™ may be effective in preventing the spread of cancer as well. The process responsible for scar formation is the same as that which causes the spread of metastases, says Dr. Bach, based on a common mechanism related to stroma cell activity. "Today we know that stroma cells support cancer growth. They create the new blood vessels that supply it with the vital nutrition necessary for its existence. Cancer cells are therefore dependent on stroma cells, which participate in the formation of new blood vessels for them. By reducing the level of activity of stroma cells, you prevent the cancer cells from replicating and spreading." Back