Understanding how and why the cells change in some cases and not others has been a major challenge for investigators.
Researchers compared telomere length and telomerase activity in biopsy specimens from 38 patients with GERD and 16 control patients. This new line of research suggests that the continuous acid bath affecting esophageal cells causes them to divide more frequently in order to regenerate the damaged lining. However, each time the cells divide, the telomeres at the end of DNA become shorter. When they become too short, the aging cell can no longer divide, Dr. Souza said.
Scientists suspect that when cells can no longer divide, other cells might infiltrate the area to make up for the loss. And those cells may be more likely to generate the acid-resistance that makes them more likely to turn cancerous.
If the telomeres get short enough, maybe the cells cant regenerate any more and maybe thats why you start to see this change, said Dr. Spechler. Perhaps the esophagus cant regenerate the normal skin-like squamous cells, and instead, it has to recruit cells from somewhere else and thats why you start getting these changes to intestinal-like cells.
Other studies by this group of UT Southwestern digestive disease specialists suggest the alternate cells that eventually take over might be bone-marrow cells.
There could be cells circulating from the bone marrow that wouldnt ordinarily end up in the esophagus. But if you shorten the telomeres enough and the esophagus cant regenerate anymore, perhaps these bone-marrow cells might have to replace that tissue, and bone-marrow cells can turn into intestinal tissue, Dr. Spechler said. This hasnt been proven, but we have some data that supports that.
In research available online prior to printing this month in Diseases of the Esophagus, Drs. Souza, Spechler and co
|Contact: Russell Rian|
UT Southwestern Medical Center