Short Telomeres Linked to Cancer Development

A study has found that abnormally short telomeres appear to play a role in the development of many types of cancer. The study was published in the May 15, 2004, issue of Clinical Cancer Research.

Researchers studied tissue from small precancerous lesions in the bladder, esophagus, large intestine, mouth, and cervix, and they found abnormal telomere lengths in 97% of the cases. Abnormally short telomeres were found in 88% of cases. Normal cells monitor the lengths of their telomeres and initiate cell suicide or halt cell division when telomeres get too short. Other research has shown in mice that cancer can occur if this monitoring system breaks down and results in chromosomal abnormalities.

The researchers used fluorescence in situ hybridization (FISH) to compare telomere length in cells from both precancerous lesions and normal cells. FISH is often used to detect gene or chromosome abnormalities, and enables scientists to examine specific chromosomal locations under a microscope for the level of fluorescence that corresponds to telomere length.

"It appears that the telomere shortening frequently observed in large advanced tumors has already occurred before it can be detected by standard diagnostic tools, when cellular changes characteristic of early precancer can only be seen through a microscope by a pathologist,” said senior author Angelo M. DeMarzo, M.D., Ph.D., associate professor of urology, pathology, and oncology at Johns Hopkins Kimmel Cancer Center (Baltimore, MD, USA).

This means that strategies directed at preventing or reversing telomere shortening may be able to lower cancer incidence. Also, assessing telomere length may help to improve early diagnosis of precancerous lesions. Previous studies by Hopkins researchers found shortened telomeres in more than 90% of precancerous lesions of the prostate, pancreas, and breast.




Related Links:
Johns Hopkins Kimmel Cancer Center