A team of researchers at Ohio State University's Comprehensive
Cancer Center have isolated and cloned a gene that may play a
role in breast cancer.
The gene is the human fibroblast growth factor-8 (FGF-8) gene.
The researchers also tracked the gene's location to a region of
chromosome 10. That area of the chromosome is also associated
with prostate cancer and glioblastoma.
The scientists believe that the gene may have a role in breast
cancer because other research has linked the FGF-8 gene to mammary
cancer in mice. Mammary cancer in mice is equivalent to breast
cancer in humans.
The FGF-8 gene is also of interest because it is activated by
androgens. Androgens, which stimulate the development of hair
growth and other male characteristics, also occur in women but
only in minute amounts.
Gene Activated By Androgens
"FGF-8 is the only growth factor gene that is activated by
androgens," said Ing-Ming Chiu, professor of internal medicine
and the researcher who led the study.
"It's a good candidate for study as an oncogene because of
its role in mouse mammary tumors. We thought the same gene in
humans might be involved in hormone-dependent cancers like breast
cancer and prostate cancer."
The research, published in the July issue of Oncogene,
also showed that the androgen dihydrotestosterone (DHT) activates
the human FGF-8 gene in laboratory cells.
"We have found that DHT activates the FGF-8 gene in laboratory-grown
breast cancer cells," said Chiu, "but that alone is
not evidence of a connection between the FGF-8 gene and breast
The researchers are now studying human breast tumor tissue provided
by breast surgeon Michael Walker at the Arthur G. James Cancer
Hospital and Research Institute for the expression of the FGF-8
"We also want to learn if this gene plays a role in male
breast cancer and in prostate cancer," said Chiu. Breast
cancer is rare in men, with an estimated 1,400 new cases and about
260 deaths occurring annually. Breast cancer in women has an estimated
184,300 new cases and 44,300 deaths.
Chiu's laboratory was the first to clone the gene from fibroblast
growth factor-1 (FGF-1), which is important for cells that form
connective tissue. The protein produced by the FGF-1 gene is present
"Our research on the FGF-8 gene is a natural extension of
our work on FGF-1," he said. Normally, the FGF-8 gene is
important during embryonic development. In adults, it is also
active in the ovaries and testes, although its role in these tissues
If Chiu and his colleagues do find a link between cancer and the
FGF-8 gene, it might mean that the gene could serve as a marker
for breast cancer. It might also provide a new target for drugs
designed to inhibit tumor development.