Natural cell protein suppresses prostate cancer
22 Feb 2011
Research at Imperial College London has found that a naturally
occurring protein called FUS inhibits the growth of prostate cancer
cells in the laboratory, and activates pathways that lead to cell
suicide.
The researchers also looked for the FUS protein in samples from
prostate cancer patients. They found that in patients with high
levels of FUS, the cancer was less aggressive and was less likely to
spread to the bone. Higher levels of FUS also correlated with longer
survival. The results suggest that FUS might be a useful marker that
can give doctors an indication of how aggressive a tumour will be.
The findings, published in the journal Cancer Research,
offer promising leads for research towards new treatments.
Prostate cancer is the most common cancer among men in the UK,
with 37,500 men diagnosed with the disease every year. Many prostate
cancers are slow growing, but in some cases the cancer is aggressive
and spreads to other parts of the body, such as the bone. These
cases are much more likely to be fatal.
"At the moment, there's no way to say whether a prostate tumour
will kill you or be fairly harmless," said Dr Charlotte Bevan,
senior author of the study, from the Department of Surgery and
Cancer at Imperial College London. "Current hormonal therapies only
work for a limited time, and chemotherapy is often ineffective
against prostate cancer, so there's a real need for new treatments.
"These findings suggest that FUS might be able to suppress tumour
growth and stop it from spreading to other parts of the body where
it can be deadly. It's early stages yet but if further studies
confirm these findings, then FUS might be a promising target for
future therapies."
Prostate cancer depends on male hormones to progress as these
hormones stimulate the cancer cells to divide, enabling the tumour
to grow. Treatments that reduce hormone levels or stop them from
working are initially effective, but eventually the tumour stops
responding to this treatment and becomes more aggressive.
Dr Bevan and her team began by exposing prostate cancer cells to
male hormones and looking at how the levels of different proteins
changed. They discovered that the hormones made the cells produce
less of the FUS protein, and examined further whether FUS might
influence cell growth by inserting extra copies of the gene for FUS
into cells grown in culture. They found that making the cells
produce more FUS led to a reduction in the number of cancer cells in
the dish.
Greg Brooke, first author of the study, from the Department of
Surgery and Cancer at Imperial College London said: "Our study
suggests that FUS is a crucial link that connects male hormones with
cell division. The next step is to investigate whether FUS could be
a useful test of how aggressive prostate cancer is. Then we might
look for ways to boost FUS levels in patients to see if that would
slow tumour growth or improve response to hormone therapy.
"If FUS really is a tumour suppressor, it might also be involved
in other cancers, such as breast cancer, which has significant
similarities with prostate cancer."