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Summer Update: Melanoma
Research Progress Suggests Optimism for
Future Cures (Philadelphia -
June 19, 2006) – In a nation of
sun-worshipers, melanoma is on the rise.
Although doctors warn their patients to
slather on sunscreen and seek cover in
the shade, messages about sun safety still
compete for the public’s attention
with magazine covers promoting that supposedly
“healthy” tan look. While
many other cancers are declining, melanoma
– the deadliest form of skin cancer
– is the fastest growing cancer
in the U.S. Early melanoma is highly treatable,
but there are limited therapies for people
with advanced stages of the disease.
At The Wistar Institute, professor Meenhard
Herlyn, D.V.M., is taking a broad-based
approach to understanding melanoma in
order to develop better treatments for
people with the disease. Herlyn leads
the largest melanoma research laboratory
outside the National Institutes of Health,
supported in part by a prestigious SPORE
(Specialized Program of Research Excellence)
federal grant, one of only three such
awards nationwide.
“We are closer to a cure for melanoma
than ever before because we have learned
so much in the past few years,”
Herlyn says. “I’m optimistic
that in the not-too-distant future we
will be able to offer patients meaningful
new treatment options.”
An important thrust of Herlyn’s
research has been to develop artificial
skin models in order to study melanoma.
Tumors don’t exist in isolation
but rather interact with other surrounding
cells and tissues – what scientists
call the tumor microenvironment –
and recent cancer research has focused
on studying tumors in this dynamic context.
Herlyn’s skin models enable him
to replicate the steps in melanoma progression.
The development of melanoma is complex;
while researchers know that UV light triggers
melanoma – both through laboratory
research, including earlier work by Herlyn,
as well as statistical associations –
the precise chain of events leading to
tumor development has remained elusive.
In particular, Herlyn’s group has
been working to understand the chemical
conversations carried on between skin
cells. These chemical messages, or signaling
pathways, keep cell division and proliferation
orderly. But disruptions in these signals
can lead to the kind of uncontrolled cell
divisions seen in melanoma. In experiments,
Herlyn has found that he can re-establish
broken communication between cells, thus
restoring control over this wayward cell
division, a promising result that could
point the way toward new targets for melanoma
therapies.
Stem cells are an important tool in Herlyn’s
melanoma research. While much of the public
discussion about stem cells has focused
on their potential in repairing diseased
or damaged tissue, stem cells are already
becoming essential in cancer research
like Herlyn’s. Recent evidence has
indicated that cancerous tumors may arise
from deviant stem cells lingering in the
body. These cancer stem cells seem to
help maintain tumors through their remarkable
powers of self-renewal. Herlyn is using
federally approved stem-cell line to understand
what role melanoma stem cells may plan
in that disease.
Outside the laboratory, Herlyn devotes
much energy to facilitating communication
among melanoma researchers and reaching
out to patient advocacy groups. He is
president of the Society for Melanoma
Research, which fosters collaborations
among basic, translational, and clinical
investigators. He also founded the Melanoma
Research Congress, which brings together
clinicians and researchers to discuss
the latest developments in the field,
and helped establish the Foundation for
Melanoma Research, which raises awareness
about melanoma and supports scientists
conducting melanoma investigations.
In other melanoma research at Wistar,
Herlyn’s wife Dorothee Herlyn, D.V.M.,
also a professor at the Institute, has
developed a novel vaccine approach to
treating melanoma that showed marked effectiveness
in a recent study. She and her colleagues
used a small peptide found in approximately
70 percent of melanomas, but not in normal
cells, to stimulate immune cells called
killer T cells to attack the melanoma
cells.
“In our experiments, we saw a strong
cancer-killing immune response when killer
T cells are stimulated with this peptide,”
says Dorothee Herlyn, who was senior author
of the study, which appeared in the March
15, 2006, issue of Cancer Research.
A substantial proportion of melanoma
patients, about 50 percent, have killer
T cells able to recognize the peptide.
Combining the prevalence of the peptide
among melanoma patients with the number
of patients whose immune cells are able
to respond to the peptide suggests that
a vaccine based on the peptide could treat
approximately a third of all melanoma
patients.
The Wistar Institute is an independent
nonprofit biomedical research institution
dedicated to discovering the causes and
cures for major diseases, including cancer,
cardiovascular disease, autoimmune disorders,
and infectious diseases, such as AIDS
and influenza. Founded in 1892 as the
first institution of its kind in the nation,
The Wistar Institute today is a National
Cancer Institute-designated Cancer Center
focused on basic and translational research.
Discoveries at Wistar have led to the
creation of vaccines for such diseases
as rabies, rubella, and rotavirus; significant
insights into the mechanisms of skin,
brain, breast, lung, and prostate cancers;
and the development of monoclonal antibodies
and other important research technologies
and tools. The Wistar Institute: Today’s
Discoveries – Tomorrow’s Cures.
On the web at www.wistar.org.
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