Research Highlights
Heart hormones may be effective cancer treatment
April 25, 2008
In studies presented by a VA researcher at
the Experimental Biology 2008 conference,
held April 5–9 in San Diego, hormones
produced by the heart eliminated
human pancreatic cancer in more than
three-quarters of the mice treated with the
hormones and eliminated human breast
cancer in two-thirds of the mice.
The work was conducted by David Vesely,
MD, PhD, chief of endocrinology, diabetes
and metabolism at the James A. Haley VA
Hospital in Tampa and a professor of medicine,
molecular pharmacology and physiology
at the University of South Florida.
Vesely has published the work in journals
such as Anticancer Research and In
Vivo. The hormone treatments have not yet
been tried in humans, but a private biotechnology
company is raising money with the
goal of beginning human clinical trials.
In the past, scientists and physicians
thought the heart was little more than a
mechanical pump, delivering blood and
oxygen to the body. But that view changed
dramatically in 1981 with the discovery
that the heart produces a protein called
atrial natriuretic factor (ANF), so-named
because it is made in the atrium of the heart
and triggers the production of urine and the
excretion of sodium.
Vesely later discovered three more
hormones that are produced from the same
gene as ANF: long acting natriuretic peptide,
which also stimulates urine production
and sodium excretion; vessel dilator, which
opens the blood vessels and lowers blood
pressure; and kaliuretic peptide, which
increases potassium excretion.
Vesely began his research on cardiac hormones
by looking at the role they can play
in diagnosing and treating congestive heart
failure. But following his wife’s death from
breast cancer in 2002—and in response
to increasing evidence that the hormones
controlled cell growth—he decided to tests
the effects of the hormones in cancer cell
cultures.
Using colon, ovarian, breast, prostate
and pancreatic cancer cells, among others,
Vesely found that the hormones kill up to 97
percent of all cancers in cell cultures within
24 hours. He then turned to trials with mice,
injecting some with pancreatic cancer cells
and others with breast cancer cells. Once
the mice developed tumors, he treated them
with the hormones.
At the end of one month, the treatment
had eliminated cancer in 80 percent of the
mice injected with human pancreatic cancer
and in 66 percent of the mice injected with
breast cancer.
The results with pancreatic cancer were
particularly exciting because it is a fastgrowing
cancer with a poor prognosis. The
disease responds poorly to chemotherapy
and radiation, and surgical removal of the
pancreas is risky. As a result, patients rarely
survive past five years. In Vesely’s study,
the pancreatic cancers that were not cured
were reduced to less than 10 percent of their
original size.
"Significantly, even in the carcinomas
that [the treatment] didn't cure, it decreased
the volume of these cancers to less than
10 percent, and the animals didn't die of
cancer—they died of old age," says Vesely.
"Thus, this is a new concept in cancer treatment.
Even if you don’t cure every cancer,
some can be treated like a 'chronic disease'
that one lives with but doesn’t die from."
Vesely also suggests that the hormones
would be a nontoxic treatment, unlike
conventional chemotherapy. "Since these
peptides are made by your own body, they
have almost no side effects. The body
doesn't recognize them as foreign, and
thus, it doesn’t develop antibodies which
can affect a person’s immune system."
In Vesely's studies with mice, the
hormones did not appear to cause any of
the unwanted side effects associated with
most cancer drugs now in use. He says,
"In the lab, we gave these peptide hormones
24 hours a day for an entire month
at the concentration which eliminates
cancers growing in living tissue, without a
single side effect."
This article originally appeared in the April-May 2008 issue of VA Research Currents.
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