Allergies may protect against pancreatic cancer
- From: J <nswex@nalid;non>
- Date: Sat, 22 Dec 2007 15:07:51 -0500
http://in.reuters.com/article/health/idINCOL16346620071221
Allergies may protect against pancreatic cancer
Fri Dec 21, 2007 11:08pm IST
By Michelle Rizzo
NEW YORK (Reuters Health) - Having a history of allergies or hay fever may
offer protection from deadly pancreatic cancer, according to a study
appearing in the International Journal of Cancer.
Ayelet Eppel, of Mt. Sinai Hospital, Toronto, Ontario, Canada, and
colleagues examined the association between a history of allergies or
asthma and the risk of pancreas cancer in a population-based, case-control
study in Ontario.
They identified cases of pancreatic cancer through the Ontario Cancer
Registry and recruited control subjects from the Ontario Familial
Colorectal Cancer Registry.
A total of 276 pancreatic cancer cases and 378 controls were included in
the study.
The investigators found that a history of allergies or hay fever was
associated with a significant 57 percent reduction in the risk of
pancreatic cancer.
The reduction in risk was stronger in men than in women. There was no
association between history of asthma and the risk of cancer of the
pancreas.
"Further research is needed to replicate these findings," Eppel told
Reuters Health.
"If replicated, our findings may be of importance to understanding the
biological mechanisms involved in pancreas cancer development -- for
example, the role of the immune system," the researcher explained, adding:
"The association between allergies and certain cancers has been found in
other studies."
SOURCE: International Journal of Cancer, December 2007.
--------------------------------------------------------------------------------------------
http://www.medicalnewstoday.com/articles/59498.php
Allergy Drug Slows Pancreatic Tumor Growth In Preclinical Studies
Main Category: Allergy News
Article Date: 31 Dec 2006 - 17:00 PDT
An anti-allergy drug in use for more than 40 years significantly reduced
tumor growth in animal models of human pancreatic cancer and also
increased the effectiveness of standard chemotherapy, say researchers at
The University of Texas M. D. Anderson Cancer Center.
In the Journal of the National Cancer Institute, the investigators report
that combining the drug, cromolyn, with chemotherapy was nearly three
times better at retarding growth of pancreatic tumors in mice compared to
the chemotherapy agent gemcitabine alone.
The finding may lead to a treatment advance for patients with pancreatic
cancer, believed to be the most lethal of all cancers. More than 95
percent of patients diagnosed with the disease die from it, and half of
those deaths occur in the first six months after diagnosis.
"Our goal is to offer longer life to these patients, and the combination
of these two agents may well do that," says the study's lead author, Craig
Logsdon, Ph.D., a professor in the Department of Cancer Biology.
Logsdon is working with physicians at M. D. Anderson to prepare for a
clinical trial. Although cromolyn is off patent and widely available, it
has been used only as a topical agent (through an inhaler, nasal spray and
eye drops), so the research team is studying how to deliver the drug
internally.
"Cromolyn seems to reduce survival mechanisms in pancreatic cancer cells
enough that when gemcitabine is added, the chemotherapy is more
effective," Logsdon says. "This is good, because chemotherapy normally has
very little effect in patients."
The JNCI study demonstrates in mouse models of human pancreatic cancer
that the cromolyn-gemcitabine combination reduced cancer growth by 85
percent compared to control animals, Logsdon says. "Cromolyn used alone
actually had a good effect on reduction of tumors compared to control
animals, which surprised us," he adds. It reduced tumor growth by 70
percent, compared to growth reduction of 50 percent when gemcitabine was
used as a single agent, compared to control animals.
No one knows exactly how cromolyn works to control allergies. However, Dr.
Logsdon has found that cromolyn can bind a specific protein produced by
cancer cells and block that protein's ability to interact with a receptor
that stimulates cancer cell growth, survival, and spreading. The
relationship between how the drug controls allergies and its anti-tumor
effect in pancreatic cancer remains unclear. "It may be possible that
cromolyn has more than one target that influences cancer," he says.
Logsdon discovered the cancer-stimulating protein, determined how it
triggers tumor growth and spread, and identified cromolyn as an inhibitor.
"Through serendipity and basic science sleuthing we may now have something
that helps patients," he says.
The study culminates Logsdon's five-year search for an agent to treat
pancreatic cancer.
Logsdon searched for genes that produced proteins secreted only by cancer
cells, which would then loop around and act on the cancer cell through a
receptor on the cell surface. "That way, we could have two potential drug
targets - the secreted protein and the receptor," he said.
Out of a long list of such genes, Logsdon and his research team selected
one called "S100P" because it is a member of the large S100 gene family,
some of which produce secreted proteins and some of which are associated
with other cancers. Further work showed that S100P over-expression was
very specific to pancreatic cancer; the protein was not found in normal
pancreatic cells. "It is important to embryonic development, but no one
knows its physiological role in adult biology," he says.
By using gene-silencing techniques, Logsdon found that when the protein is
disabled, cancer growth is slowed. "S100P plays a role in tumor
development because it causes cancer cells to grow faster, survive better,
and be more invasive," he says.
Logsdon found that S100P interacts with a receptor known as "RAGE" which
also plays a role in diabetes, arthritis and Alzheimer's disease. If RAGE
is blocked in pancreatic cancer cells, addition of synthetic S100P to the
tumor does not accelerate growth.
While Logsdon was defining S100P in pancreatic cancer, a Japanese research
team working on allergies ran an experiment to see which proteins "stuck"
to anti-allergy drugs, including cromolyn. Several members of the S100
family did. Logsdon then discovered that the drug also bound to S100P. He
applied cromolyn to laboratory pancreatic cancer cells, and found that
tumor growth was slowed. A larger effect was seen when the chemotherapy
agent gemcitabine was combined with cromolyn.
Logsdon suspects that cromolyn may have other anti-tumor effects, a theory
which he is currently testing. "For me this is pretty thrilling," he says.
"In a relatively short time, we have gone all the way from discovering a
molecule to preparations for a clinical trial."
----------------------------
Article adapted by Medical News Today from original press release.
----------------------------
The study was funded by the Lockton Endowment and the M. D. Anderson
Cancer Center Pancreatic SPORE grant from the National Cancer Institute.
Working with Logsdon were M. D. Anderson researchers Thiruvengadam
Arumugam Ph.D. and Vijaya Ramachandran, Ph.D
.
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