Botox can slow tumour growth
22 August 2014
Research at Columbia University Medical Center and the Norwegian
University of Science shows that cutting off the nerves to tumours
using surgery or Botox can reduce the growth of cancer cells.
Using three different mouse models of stomach cancer, the
researchers found that when they performed a procedure called a
vagotomy to cut the nerves, the surgery significantly slowed tumour
growth and increased survival rates.
Removing nerve connections from only one side of the stomach
allowed cancer to continue growing on the other side (with the
intact nerves), providing further evidence of the importance of
nerves in tumour growth.
The researchers then tried to block transmission of nerve signals
pharmacologically. They found that when they injected Botox into
mice, the drug proved to be as effective as surgery at reducing
stomach cancer growth. The research has been published in the
journal Science Translational Medicine.
Microscope image of stomach cancer with and
without Botox injections. Cells from the anterior (left) and posterior
(right) halves of the stomach of mice with cancer. Only the anterior
stomach half was injected with Botox.
“Scientists have long observed that human and mouse cancers
contain a lot of nerves in and around the tumour cells,” said Dr.
Timothy C Wang, the Dorothy L. and Daniel H. Silberberg Professor of
Medicine at Columbia’s Herbert Irving Comprehensive Cancer Center.
“We wanted to understand more about the role of nerves in the
initiation and growth of cancer, by focusing on stomach cancer.”
“We found that blocking the nerve signals makes the cancer cells
more vulnerable — it removes one of the key factors that regulate
Botox prevents nerve cells from releasing a neurotransmitter
called acetylcholine. In the case of cosmetic treatment, for
example, blocking acetylcholine helps to lessen facial wrinkles by
causing temporary paralysis of the muscles. Because acetylcholine
also ordinarily stimulates cell division, using Botox to prevent
acetylcholine release might help slow the growth of cancer.
Botox is taken in by the nerves, where it
prevents the release of neurotransmitters, in this case, for a
tumour in the stomach.
Dr Wang’s team also found evidence of the effectiveness of
targeting nerves for cancer treatment in human patients when they
compared 37 patients who had a recurrence of stomach cancer many
years after surgery. Of the 13 patients who had had a vagotomy as
part of their procedure, in all but one case, tumours did not
develop in regions where the nerve connections had been severed. By
contrast, tumours were found in the same region of the stomach in
all 24 patients who had not had a vagotomy.
Next, Dr. Wang’s team plans to investigate the effectiveness of
nerve-targeted therapy used in combination with other cancer
treatments. Initial experiments have shown that blocking nerves
makes cancer cells more vulnerable to chemical agents. Botox® used
in combination with chemotherapy in mice increases survival rates up
to 35 percent, compared with chemotherapy alone.
A limitation of the current studies is that they focus primarily
on early stages of stomach cancer. “In the future, we’d really like
to look at how we can use this method of targeting nerves to stop
the growth of more advanced tumours,” Dr. Wang said. His laboratory
hopes to develop drugs that block neurotransmitter receptors. This
approach would be more effective than surgery or Botox on more
invasive forms on cancer, as such drugs would be able reach cells
that have broken away from the main tumour.