November 19, 2008 -- Scientists in Tennessee are reporting that a gene therapy
technique called “gene silencing” shows promise for improving the effectiveness
and expanded use of transplants of insulin-producing cells to treat
insulin-dependent, or type 1, diabetes. The study is scheduled for the December
1 issue of ACS’ Molecular
Pharmaceutics, a bi-monthly journal.
In the new study, Ram
Mahato, Guofeng Cheng, and Lin Zhu point out that transplantation of the
pancreas’s insulin producing cells, called islet cells, has great potential for
treating patients with insulin-dependent diabetes. However, the procedure
currently is ineffective for most people due to a tendency of the body’s immune
system to reject transplanted cells. Studies by others indicate that a specific
enzyme, caspase-3, plays a key role in carrying-out this destructive
To address this problem, the scientists genetically modified
islet cells in the laboratory to turn off, or “silence” the gene responsible for
producing caspase-3. When the modified cells were transplanted into the kidneys
of mice with insulin-dependent diabetes, the blood glucose levels of the mice
became normal for up to 32 days, the scientists say. When the cells were
removed, the blood glucose levels of the mice returned to high levels similar to
pre-transplantation levels, confirming that the transplanted cells were
functional and effective, the researchers say.
News release courtesy of The American Chemical Society, a nonprofit organization chartered by the U.S. Congress and a global leader in
providing access to chemistry-related research through its multiple databases,
peer-reviewed journals and scientific conferences.