University of California: Curcumin, the main
component in the spice turmeric, suppresses a cell
signaling pathway that drives the growth of head and
neck cancer, according to a pilot study using human
saliva by researchers at UCLA’s Jonsson
Comprehensive Cancer Center.
The inhibition of the cell signaling pathway also
correlated with reduced expression of a number of
pro-inflammatory cytokines, or signaling molecules,
in the saliva that promote cancer growth, said Dr.
Marilene Wang, a professor of head and neck surgery,
Jonsson Cancer Center researcher and senior author
of the study.
“This study shows that curcumin can work in the
mouths of patients with head and neck malignancies
and reduce activities that promote cancer growth,”
Wang said. “And it not only affected the cancer by
inhibiting a critical cell signaling pathway, it
also affected the saliva itself by reducing
pro-inflammatory cytokines within the saliva.”
The study appears Sept. 15 in Clinical Cancer
Research, a peer-reviewed journal of the American
Association for Cancer Research.
Turmeric is a naturally occurring spice widely used
in South Asian and Middle Eastern cooking and has
long been known to have medicinal properties,
attributed to its anti-inflammatory effects.
Previous studies have shown it can suppress the
growth of certain cancers. In India, women for years
have been using turmeric as an anti-aging agent
rubbed into their skin, to treat cramps during
menstruation and as a poultice on the skin to
promote wound healing.
A 2005 study by Wang and her team first showed that
curcumin suppressed the growth of head and neck
cancer, first in cells and then in mouse models. In
the animal studies, the curcumin was applied
directly onto the tumors in paste form. In a 2010
study, also done in cells and in mouse models, the
research team found that the curcumin suppressed
head and neck cancer growth by regulating cell
cycling, said scientist Eri Srivatsan, an adjunct
professor of surgery, article author and a Jonsson
Cancer Center researcher who, along with Wang, has
been studying curcumin and its anti-cancer
properties for seven years.
The curcumin binds to and prevents an enzyme known
as IKK, an inhibitor of kappa β kinase, from
activating a transcription factor called nuclear
factor kappa β (NF?β), which promotes cancer growth.
In this study, 21 patients with head and neck
cancers gave samples of their saliva before and
after chewing two curcumin tablets totaling 1,000
milligrams. One hour later, another sample of saliva
was taken and proteins were extracted and IKKβ
kinase activity measured. Thirteen subjects with
tooth decay and five healthy subjects were used as
controls, Wang said.
Eating the curcumin, Wang said, put it in contact
not just with the cancer but also with the saliva,
and the study found it reduced the level of cancer
enhancing cytokines.
An independent lab in Maryland was sent blind
samples and confirmed the results—the
pro-inflammatory cytokines in the saliva that help
feed the cancer were reduced in the patients that
had chewed the curcumin and the cell signaling
pathway driving cancer growth was inhibited, Wang
said.
“The curcumin had a significant inhibitory effect,
blocking two different drivers of head and neck
cancer growth,” Wang said. “We believe curcumin
could be combined with other treatments such as
chemotherapy and radiation to treat head and neck
cancer. It also could perhaps be given to patients
at high risk for developing head and neck cancers—smokers,
those who chew tobacco and people with the HPV
virus—as well as to patients with previous oral
cancers to fight recurrence.”
The curcumin was well tolerated by the patients and
resulted in no toxic effects. The biggest problem
was their mouths and teeth turned bright yellow.
“Curcumin inhibited IKKβ kinase activity in the
saliva of head and neck cancer patients and this
inhibition correlated with reduced expression of a
number of cytokines,” the study states. “IKKβ kinase
could be a useful biomarker for detecting the
effects of curcumin in head and neck cancer.”
To be effective in fighting cancer, the curcumin
must be used in supplement form. Although turmeric
is used in cooking, the amount of curcumin needed to
produce a clinical response is much larger.
Expecting a positive effect through eating foods
spiced with turmeric is not realistic, Wang said.
The next step for Wang and her team is to treat
patients with curcumin for longer periods of time to
see if the inhibitory effects can be increased. They
plan to treat cancer patients scheduled for surgery
for a few weeks prior to their procedure. They’ll
take a biopsy before the curcumin is started and
then at the time of surgery and analyze the tissue
to look for differences.
“There’s potential here for the development of
curcumin as an adjuvant treatment for cancer,” Wang
said. “It’s not toxic, well tolerated, cheap and
easily obtained in any health food store. While this
is a promising pilot study, it’s important to expand
our work to more patients to confirm our findings.”
Finding ways to better treat head and neck cancers
is vital as patients often require disfiguring
surgery, often losing parts of their tongue or mouth.
They also experience many side effects, including
difficulty swallowing, dry mouth and have the
potential for developing another oral cancer later.
The study was funded by Veterans Affairs Greater Los
Angeles Health System, West Los Angeles Surgical
Education Research Center, UCLA Academic Senate, the
National Institutes of Health and the Veterans
Administration.
UCLA's Jonsson Comprehensive Cancer Center has more
than 240 researchers and clinicians engaged in
disease research, prevention, detection, control,
treatment and education. One of the nation's largest
comprehensive cancer centers, the Jonsson center is
dedicated to promoting research and translating
basic science into leading-edge clinical studies. In
July 2011, the Jonsson Cancer Center was named among
the top 10 cancer centers nationwide by U.S. News &
World Report, a ranking it has held for 11 of the
last 12 years.
For more information
http://www.cancer.ucla.edu
(MDN)
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