Main Category:
Pancreatic Cancer
Article Date: 26 Aug 2013 - 1:00 PDT
New research led by scientists at The University of Texas
Health Science Center at Houston (UTHealth) and Baylor College of
Medicine could aid efforts to diagnose and treat one of the most lethal
and hard-to-treat types of
cancer.
In the
EMBO Molecular Medicine journal, the investigators
report that they have identified a new molecular mechanism that
contributes to the spread of malignant tumors in the pancreas. The hope
is that drugs could one day be developed to block this pathway.
Most people with
pancreatic cancer
die within one to two years of diagnosis and it is expected to claim
38,460 lives in the United States in 2013. There are currently no
effective tests for early detection and no effective therapies for the
fast-spreading form.
The study focused on the previously established link between zinc and
pancreatic cancer and sought to identify a molecular mechanism
responsible for the elevated levels found in human and animal cells.
Zinc is an essential trace element and small amounts are important for
human health.
"We were the first to show that zinc transporter ZIP4 was a marker for
pancreatic cancer," said Min Li, Ph.D., the study's senior author and
associate professor and director of the Cancer Research Program in the
Vivian L. Smith Department of Neurosurgery at the UTHealth Medical
School. "We knew there was a link but we didn't know what it was."
Li is on the faculty of The University of Texas Graduate School of
Biomedical Sciences at Houston, which is a joint venture of UTHealth and
The University of Texas MD Anderson Cancer Center.
Zinc levels are regulated by ZIP4, which acts as a master switch, and
the researchers designed experiments to determine what happens when the
switch is flipped on, Li said.
In an animal model of pancreatic cancer, the scientists observed how the
initiation of ZIP4 triggered the activation of two downstream genes,
which in turn accounts for the increased
tumor growth. Scientists describe this as a signaling cascade.
"Pancreatic cancer is among the worst of all cancers. It is imperative
to define the mechanism of this deadly disease. We have recently
demonstrated a novel biological role for the zinc transporter ZIP4 in
pancreatic cancer; however, the molecular pathway controlling this
phenomenon remains elusive. This study provides a comprehensive
mechanism for ZIP4-mediated pancreatic cancer growth involving the
activation of a transcription factor CREB and an oncogenic miR-373, and
reduction in key tumor suppressor genes," said Yuqing Zhang, Ph.D.,
co-first author of the study.
Jingxuan Yang, Ph.D., co-first author and research scientist at the
UTHealth Medical School, said, "Our findings in this study define a
novel signaling axis promoting pancreatic cancer growth, providing
potential mechanistic insights on how a zinc transporter functions in
cancer cells and may have broader implications as abnormal zinc
concentration in the cells plays an important role in many other
diseases."
"The results we reported in this study may help the design of future
therapeutic strategies targeting the zinc transporter and microRNA
pathways to treat pancreatic cancer," said Xiaobo Cui, M.D., Ph.D.,
study co-first author and postdoctoral research fellow at the UTHealth
Medical School.
http://www.medicalnewstoday.com/releases/265195.php