What if a substance was found that normalizes out-of-control cell growth? The result
could be a way to treat and prevent cancer. And a new study offers hope that discovery may
have already been made. Scientists from the University of Chicago have just published
groundbreaking research in the journal Cell which concludes a powerful
compound exists that can restore a healthy balance to cell processes. It's not a new
chemotherapy agent or drug but one derived from nature -- retinoic acid, a derivative
of vitamin A.
According to the American Cancer Society, estrogen fuels the growth of two
out of three breast cancers.
The female hormone can spur on cancer by
altering the expression of certain genes,
resulting in breast cells that become malignant and proliferate. The University of Chicago
study found that retinoic acid can also alter these same estrogen-sensitive genes. But
instead of causing cells to grow without restraint, a hallmark of cancer, retinoic acid
restored normal balance to the cells and inhibited their growth.
"This work reveals important insights on the interplay between vitamin A and estrogen
action," said Myles Brown, MD, professor of medicine at Harvard Medical School and
the Dana Farber Cancer Institute, in a statement to the media. "These insights will
hopefully lead to new approaches for the prevention and treatment of the most common form
of breast cancer."
Retinoic acid has already demonstrated cancer fighting effects in previous studies and it
is currently used to treat a rare form of leukemia. In addition, earlier research has
associated retinoic acid with the halting of breast cancer cell proliferation.
For the new study, Kevin White, PhD, professor of human genetics and director of the
Institute for Genomics and System Biology at the University of Chicago, and colleagues
focused on documenting cell receptors for the vitamin A derivative. They used a process
dubbed ChIP-chip analysis that combines chromatin immunoprecipitation
(ChIP), which locates where the retinoic acid receptors are bound to the genome,
with micro-array gene-chip analysis, which measures the expression levels of
specific genes.
This merging of techniques allowed the scientists to map out the complete genetic effects
of retinoic acid and its receptors in a cell line provided by patients who had
estrogen-fueled breast cancers. The results showed that 39 percent of the genomic regions
bound by the estrogen receptor known as alpha overlapped with the estrogen receptors bound
by retinoic acid.
What's more, they discovered that estrogen and retinoic acids receptors often competed to
activate or repress many of the same genes. For example, estrogen increased expression of
the same 139 genes that retinoic repressed and retinoic acid activated 185 genes that
estrogen repressed. For approximately140 genes, estrogen and retinoic acid had the same
effect.
So what does all this mean? As the scientists explained in their press statement, they now
have evidence that estrogen and retinoic acid carry on a kind of "cross talk".
So, although they can have opposite effects, certain estrogen and retinoic acid receptors
on cells activate each other and normalize each other. That provides what the researchers
call "an additional level of control for achieving a balanced regulation of
expression."
The study also uncovered another way retinoic acid could help fight breast cancer. Some of
the genes that are expressed in malignant breast tumors don't have estrogen receptors so
anti-estrogen drugs can't be
used as therapies. That makes so-called double or triple negative breast cancers extremely
difficult to treat and, subsequently, they carry poor prognoses. However, in the new
study, the researchers found these forms of cancerous cells did respond positively to the
vitamin A derivative.
The new study may have produced a new way to help predict long-term survival for
breast cancer patients,
too. When the researchers compared the effects of retinoic acid on tissues from 295 breast
cancer patients with the results from the scientists' initial study using a typical breast
cancer cell line, they discovered that the more strongly a tumor responded to retinoic
acid, the greater the chances of long-term survival and a lack of relapse.
"Understanding all the components of this process could be used against breast cancer
in three ways," said Dr. White, in the media statement. "It suggests new ways to
think about preventing the disease in those at high risk. It offers molecular tools that
could provide a more precise diagnosis and predict outcomes. It could also be used to
enhance current therapies, making existing drugs, such as tamoxifen, that selectively
block estrogen's effects even more powerful, or even to develop new anti-cancer
drugs."
As reported earlier in Natural News (http://www.naturalnews.com/025495_c...), researchers are also studying
vitamin D to see what role it may play in fighting breast cancer. It appears to help
protect against breast cancer by keeping normal cell growth in check. (Natural
News, 8.24.2009, S. L. Baker)
http://www.naturalnews.com/026901_cancer_brst_cancer_Retinoic_acid.html