Ronald DePinho, MD, and colleagues at the Dana-Farber Cancer Institute and Harvard Medical School, published their findings in the journal Science (Vol. 287, No. 5,456). Dr. DePinho is an American Cancer Society (ACS) Research Professor, one of the Society?s most prestigious awards given to outstanding cancer researchers who have contributed significantly to a particular area within cancer research.

Dr. DePinho and his colleagues found that mice with abnormally short telomeres ? the DNA sequences at the end of chromosomes ? are especially prone to developing liver cirrhosis when the liver is injured. The researchers were able to prevent cirrhosis in these mice by the administration of a gene therapy that temporarily activates telomerase, the enzyme that lengthens the telomeres.

Because of this finding, Dr. DePinho concluded, "It is reasonable to anticipate the activation of telomerase could inhibit the development of liver cirrhosis or terminal liver failure in humans."

However, more study is needed before this new approach is tried in the clinic because of the complex association of telomerase levels and cancer. Because many types of cancer cells have abnormally high telomerase levels, gene therapy or drug therapy to block telomerase has been suggested as a potential anticancer therapy. On the other hand, depletion of telomeres by conditions such as cirrhosis that lead to long-term tissue damage can also increase cancer risk. Dr. DePinho and colleagues suggest that the key to preventing liver cancer with telomerase is to increase the enzyme?s activity temporarily rather than permanently.

The ACS predicts there will be about 15,300 new cases of liver cancer in the year 2000 in the US. About 13,800 people are expected to die of the disease.