Blocking Signaling Protein Prevents Prostate Cancer Spread, Jefferson Scientists Find
Researchers
at the Kimmel Cancer Center at Jefferson in Philadelphia have shown
that by blocking a signaling protein, they can prevent prostate cancer
cells from metastatic dissemination. The work opens the door to future
studies examining the protein as a target for therapies aimed at
keeping prostate cancer at bay.
In
a series of experiments in both the laboratory and animal models, Marja
Nevalainen, M.D., Ph.D., associate professor of Cancer Biology at
Jefferson Medical College of Thomas Jefferson University and her
co-workers found that the protein, Stat3, is key to the metastatic
progression of prostate cancer. Dr. Nevalainen’s group reports its
findings in the June 2008 issue of the American Journal of Pathology.
According
to Dr. Nevalainen, previous studies have shown that Stat3 is very
active in metastatic prostate cancer, and the protein has been linked
to cancer metastasis in several different cancer types. Because
metastatic prostate cancer lacks effective therapies, understanding the
molecular changes involved is critical.
To
clarify Stat3’s role in prostate cancer progression, she and her
co-workers performed several studies. In one case, the scientists used
an antibody for Stat3, for example, to show that it is activated in 77
percent of lymph nodes and 66 percent of bone metastases in human
prostate cancer. In another experiment, the scientists prompted mouse
prostate cancer cells to overproduce the normal Stat3 protein by
delivering it through a virus vehicle. They saw a dramatic increase in
prostate cancer metastases compared to controls. Specifically, in mice
lacking a working immune system, they showed that Stat3 caused a
33-fold increase in metastases.
“This
is the first proof that Stat3 may have a major effect on metastatic
dissemination of prostate cancer,” Dr. Nevalainen says. “Stat3 now
becomes a potential drug target to interfere with the metastatic
progression of prostate cancer.”
While
her team’s results “open up other opportunities to study the mechanism
of prostate cancer metastases,” Dr. Nevalainen notes that Stat3 might
have possible use in the prevention of primary prostate cancer from
progressing to metastatic disease as well.
She suggests that studies testing newly developed Stat3 inhibitors in prostate cancer should include testing their effectiveness
in blocking prostate cancer metastases in experimental animal models.
Media Only Contact:
Ed Federico
Thomas Jefferson University Hospital
Phone: (215) 955-6300
Published: 5/30/2008