Worm Study Indentifies Function of Gene Damaged in CLL

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Thursday January 3 5:20 PM ET

Worm Genome May Offer Clues to Type of Leukemia

By Amy Norton

NEW YORK (Reuters Health) - Using the genetic

blueprint of the worm, researchers have identified

about two dozen genes that help repair genetic damage

in cells--one of which is the counterpart to a human

gene commonly involved in a type of leukemia.

The findings ``open up new possibilities'' for

studying this gene in humans, and may help uncover new

gene mutations that contribute to cancer, the study's

lead author told Reuters Health.

All of the genes the research team found are involved

in the DNA damage response. Many human cancers arise

when defects in such genes prevent the normal process

in which cells with DNA damage are either repaired or

programmed to self-destruct. Cancer occurs when

abnormal cells are allowed to divide and proliferate

out of control.

Marc Vidal of Harvard Medical School (news - web

sites) in Boston, Massachusetts, and his colleagues

scoured the genome of the roundworm C. elegans for

genes that take part in the DNA damage response. Of

the 23 they pinpointed, one appears to be the

counterpart to the human BCL3 gene, which is commonly

altered in cases of chronic lymphocytic leukemia

(CLL)--a form of leukemia that usually strikes older

adults.

The investigators, from the United States and Germany,

report their findings in the January 4th issue of

Science.

The complete set of genes for C. elegans was mapped in

1998, when the rough draft of the human genome was

still a work-in-progress. While the roundworm is only

about 1 millimeter long and lives a few weeks at best,

it shares many of its genes with humans. Therefore,

scientists can study the worm genome for clues to

human disease.

Vidal said that while BCL3 is known to be mutated in

CLL, its function has not been fully clear. The fact

that this study suggests it takes part in the DNA

damage response is a ``little bit surprising,''

according to the researcher.

Besides offering new directions for research on BCL3,

Vidal noted, this study identifies a number of other

genes with potential human counterparts that, when

mutated, may help lead to cancer.

SOURCE: Science 2002;295:127-131.

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