There are so many things that go wrong in prostate
cancer, and some of them are tiny. MicroRNAs fall into this category.
They're little factory workers — molecules that help regulate cells'
production of specific proteins. Their job is small but important;
what they do or don't do can affect cell growth, death, and differentiation
(how "normallooking" the cell is; healthy cells are well differentiated;
cancer cells are poorly differentiated). Alterations in the work
of these microRNAs have been found in several different cancers,
including prostate cancer. "Both increased and decreased expression
of certain microRNAs are known to affect cancer cells," explains
Brady scientist William G. Nelson, M.D, Ph.D. Although nobody knows
for sure which particular switch turns microRNAs up or down, Nelson
suspects that methylation of certain sections of DNA called cytosine
bases may play a big role here. "This type of change has been found
to affect many types of genes in prostate cancer," Nelson says.
In studies of human prostate cancer cells, Nelson is looking for
these changes near 37 microRNA genes, using a new technique developed
in his laboratory, called COMPARE-MS.
“We hope our
lead to new diagnostic tests,
and to new strategies for
treating and even for preventing
The next step, Nelson says, is to try to reverse
the abnormal cytosine methylation patterns, "and see whether we
can restore the normal expression of the microRNAs. We hope our
findings can lead to new diagnostic tests, and to new strategies
for treating and even for preventing prostate cancer."
In another series of studies, Shawn Lupold, Ph.D.,
the Virginia and Warren Schwerin Scholar, is investigating how hormones
affect microRNAs — and how this, in turn, affects prostate cancer.
Specifically, he wants to find out how male hormones, called androgens,
and vitamin D — known to be very important in regulating normal
and cancerous prostate cells — affect microRNAs in the prostate.
He believes that these microRNAs, in turn, significantly affect
prostate cell growth, differentiation, and death. "These studies
should reveal abnormal microRNAs that exist within prostate cancer,
and what we learn may be very important in developing new forms