By Emma Patten-Hitt, PhD
NEW YORK (Reuters
Health) - With some help from the Human Genome Project, three
researchers have found a new gene that blocks cancer growth.
When cancer-blocking
genes, known as tumor suppressor genes, are working properly,
they help prevent abnormal cells from growing out of control.
Missing or mutated tumor suppressor genes lose this ability, making
it more likely that cancer will develop.
So far, researchers
have identified about 30 tumor suppressor genes and estimate that
there are at least 100 more. Preliminary evidence suggests that
the new gene, dubbed ST7, may prevent the growth of new blood
vessels that tumors require to survive.
``The data
we have is preliminary, but it seems that ST7 may be regulating
the production of new blood vessels, without which tumors cannot
grow beyond a certain size,'' lead author Dr. Jean C. Zenklusen
of the National Institutes of Health in Bethesda, Maryland, told
Reuters Health. ``This is the first tumor suppressor gene that
has been shown to work in this way.''
According
to Zenklusen, the tumor suppressor gene, located on human chromosome
7, contributes to breast, colon, ovarian, liver, pancreatic, skin,
prostate, gastric, bladder and kidney cancers. But the ST7 protein
appears not to be a factor in cancers that do not require the
growth of new blood vessels, such as lymphomas. Zenklusen and
colleagues describe their findings in the April issue of Nature
Genetics.
Data from
the Human Genome Project--the collaborative effort to map the
entire human genome--contributed much to finding the new tumor
suppressor gene, Zenklusen said. The researchers knew where on
the chromosome that the gene could be found, and the sequence
of genes in the area had already been described. ``Before the
genome project, one had to identify all the gene candidates in
the region by a tortuous process that involved complicated techniques,''
he explained.
``This finding
is an excellent example of how individual researchers, aided by
the availability of the near-complete sequence of the human genome,
can make major advances in our knowledge of the genetic basis
of disease in a matter of a few years or less,'' Dr. Francis S.
Collins, director of the National Human Genome Research Institute,
said in a press release accompanying the study.
``Next we
want to determine the function of ST7,'' Zenklusen said. ``We
are looking at which pathways are disrupted by the absence of
the gene; also we are looking to see, if we can determine which
other genes are affected by the absence or presence of ST7,''
he said. ``It can be the work of a lifetime--but the fun has just
begun.''
|
