The nature vs nurture theory has been hotly debated in
every field of medicine. In prostate cancer, the battle
is finally over as nature strikes a blow that's below
the belt — so to speak. Genes have just knocked out
the environment, according to a paper in Cancer Research.
Their February 15 issue claims that men with a certain
mutation in the KLF6 gene are much more likely to get
this disease.
This latest information has implicated
the KLF6 gene in lung, colorectal and hepatocellular
cancers, as well as in malignant gliomas and nasopharyngeal
cancer. "What is common here is the mechanism. Variant
forms of the gene are biologically active. They're growth-promoting,"
said senior author Dr John Martignetti of New York's
Mount Sinai School of Medicine in a telephone interview.
"The gene was discovered by Scott
Friedman about five years ago. That was key to our project,"
he went on to say, referring to work published in Science
in 2001. According to Dr Martignetti, the next eureka
moment occurred when collaborator "Goutham Narla realized
that the gene mapped to a chromosome site that was deleted
in many prostate cancer tumours."
The 2001 Science paper found
that at least one copy of KLF6 was missing in the majority
of prostate tumours. The Cancer Research paper
moves beyond tumours and looks at the genetic makeup
of prostate cancer patients. Blood samples from 3,411
men were divided into three classes: those with prostate
cancer and a family history of the disease, those with
prostate cancer but no family history, and those without
prostate cancer.
Researchers found that about 17%
of the patients with a family history of the disease
and 15% of patients with no such history carried at
least one copy of a KLF6 mutant, but only 11% of the
controls did. This difference is statistically significant,
and means that carrying even one defective copy of KLF6
increases prostate cancer risk dramatically.
"Studies are showing that in lung
and prostate cancer, these mutations have prognostic
value. They are linked to more aggressive forms of cancer,"
he said. Future genetic testing for KLF6 mutations could
help point out which men need close monitoring even
before they have any disease. With luck, this will lead
to earlier diagnoses and better prognoses for these
men.
Cancer Res Feb 15, 2005 65:1213-22
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