identify unique sperm gene
may open new avenues for cancer research
Westbrook is part of the Center for Research in Reproductive
Health team that identified SPAN-X, a gene found in sperm
and also some cancers.
biologists at the U.Va. Health
System have identified a new gene, called SPAN-X, that could
eventually lead to better diagnosis and treatment for certain
first it was believed that SPAN-X is only found in normal testes.
Recently, the researchers found that SPAN-X is also present in
some tumors, including skin, breast, prostate and ovarian. Their
findings are reported in this month's issue of Biology of Reproduction.
"In the testis, SPAN-X is found in the nuclear membrane of developing
sperm, which suggests it may play an important role in the maturation
of the sperm nucleus. This is a highly specific function, and
we were surprised to find that this gene is also present in certain
cancer cells," said Anne Westbrook, a research associate at U.Va.
and leader of the team that discovered the new gene.
Green= X chromosome
Red= SPAN-X protein
research has shown that certain proteins are found only in the
testis and are introduced for the first time during puberty. To
protect them from being attacked as a foreign invader, the male
body has adapted to hide these proteins from the immune system.
However, since these proteins are not protected from the immune
system when they are produced by cancer cells, researchers believe
they will be good targets for anti-tumor therapy.
aren't sure yet what role SPAN-X might play in diagnosing or treating
these cancers, but the finding raises interesting questions about
the role of SPAN-X in tumor progression," Westbrook said.
on our findings, it seems possible that as some tumors become
cancerous and develop irregularly, they may begin to mimic the
way genes are expressed during sperm formation," said John
Herr, director for the Center for Research in Reproductive Health
in whose laboratory the research was performed.
finding is likely to open several new avenues of research. The
researchers will explore several possibilities in hope of identifying
treatment targets for specific cancers.
they are looking at a large number of stored tissue samples to
see how frequently SPAN-X is present in different cancers. If
particular levels of SPAN-X are associated with a specific type
of cancer, it could eventually lead to a test that would allow
for earlier diagnosis of that cancer, Herr explained.
In addition, Herr said that greater understanding of how SPAN-X
functions in both normal and cancer cells could help determine
if it may be a useful component of a cancer vaccine or if blocking
its function could slow down or stop cancer.