October 10, 2003
New Penn Study Shows Genes May Influence Smoking Cessation
(Philadelphia, PA) Smokers with a specific combination
of two genetic variants may be more likely to remain
abstinent and less prone to relapse when trying to quit
smoking, a study by researchers from the Tobacco
Use Research Center of the University of Pennsylvania
School of Medicine indicates. This research
– which will appear in the October issue of Health
Psychology- has important implications for the development
of more effective treatment strategies that are tailored
to individual smokers’ needs.
“While previous research has examined the effects
of genes related to dopamine, a chemical in the brain
associated with reinforcing the effects of nicotine,
this study provides the first evidence that genes that
alter dopamine function may influence smoking cessation
and relapse during treatment,” said lead author
Caryn Lerman, Ph.D., Associate Director
for Cancer Control and Population Science at the Abramson
Cancer Center of the University of Pennsylvania
and Professor in Penn’s School of Medicine
and the Annenberg Public Policy Center.
Dr. Lerman led a research team that examined 418 smokers
enrolled in a randomized placebo-controlled clinical
trial of bupropion for smoking cessation. Participants
provided blood samples and received bupropion or placebo
plus seven sessions of behavioral group counseling.
Smoking status, abstinence symptoms and side effects
were recorded weekly, and smoking status was verified
at the end of treatment and again at a six-month follow-up
appointment.
Researchers found that participants with particular
variants of the SLC6A3 dopamine transporter gene and
the DRD2 dopamine receptor gene reported significantly
higher abstinences rates and a longer time before relapse
than smokers carrying other variants of these genes.
“This gene-gene interaction provides new evidence
for the effects of dopamine genes on prospective smoking
cessation and underscores the importance of not limiting
genetic investigations of smoking behavior to single
gene effects,” said Lerman.
In previous research, the same variant of the dopamine
transporter gene has been associated with higher levels
of dopamine in the brain and this may facilitate smoking
cessation. “Future smoking cessation studies should
evaluate genetic predisposition, as well as the influence
of psychological and environmental factors that may
promote relapse,” stated Lerman.
This research will appear in Health Psychology in an
article titled “Effects of Dopamine Transporter
and Receptor Polymorphisms on Smoking Cessation in a
Bupropion Clinical Trial.”
This research was funded by the National Cancer Institute
and the National Institute on Drug Abuse and was conducted
by the University of Pennsylvania/Georgetown University
Transdisciplinary Tobacco Use Research Center.
For
a printer friendly version of this release, click
here.
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The Abramson Cancer Center
of the University of Pennsylvania was established in
1973 as a center of excellence in cancer research, patient
care, education and outreach. Today, the Abramson Cancer
Center ranks as one of the nation’s best in cancer
care, according to US News and World Report, and is
one of the top five in National Cancer Institute (NCI)
funding. It is one of only 39 NCI-designated comprehensive
cancer centers in the United States. Home to one of
the largest clinical and research programs in the world,
the Abramson Cancer Center of the University of Pennsylvania
has 275 active cancer researchers and 250 Penn physicians
involved in cancer prevention, diagnosis and treatment.
PENN Medicine is a $2.2
billion enterprise dedicated to the related missions
of medical education, biomedical research, and high-quality
patient care. PENN Medicine consists of the University
of Pennsylvania School of Medicine (founded in 1765
as the nation's first medical school) and the University
of Pennsylvania Health System (created in 1993 as the
nation's first integrated academic health system).
Penn's School of Medicine is ranked
#2 in the nation for receipt of NIH research funds;
and ranked #4 in the nation in U.S. News & World Report's
most recent ranking of top research-oriented medical
schools. Supporting 1,400 fulltime faculty and 700 students,
the School of Medicine is recognized worldwide for its
superior education and training of the next generation
of physician-scientists and leaders of academic medicine.
Penn Health System consists of four
hospitals (including its flagship Hospital of the University
of Pennsylvania, consistently rated one of the nation's
"Honor Roll" hospitals by U.S. News & World Report),
a faculty practice plan, a primary-care provider network,
three multispecialty satellite facilities, and home
health care and hospice.
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