Winship Urologist First to Grow Cancer "Organoid" in Space
Researchers at Emory University’s Winship Cancer Institute will use
the next NASA space shuttle as a "zero gravity" laboratory to learn
more about prostate cancer and bone metastasis.
Leland Chung, PhD, will be
the first cancer investigator to grow a prostate cancer "organoid,"
or artificial tumor, in space. The space shuttle, scheduled for launch
on January 16, 2003, will carry prostate cancer cells and bone stroma,
or tissue framework, cells into space in a NASA-engineered "bioreactor,"
which recreates the natural environment for tumor development and progression.
The shuttle will return to earth on February 2, 2003.
Dr. Chung, a urology professor,
is seeking to understand how prostate cancer cells grow and communicate
with other cells in the body. He and his co-investigators at NASA are
also studying how zero gravity can be used as a tool to advance science,
using the space shuttle as a laboratory to facilitate the growth and
study the behavior of prostate cancer cells in the body.
Dr. Chung notes that an important
goal of this experiment is to discover relevant genes that may "turn
on or turn off" during the cascade of prostate cancer cells to the bone.
"This study may provide us with insight into novel genes of diagnostic
or prognostic value and may offer new targets for treatment of cancer
metastasis," says Dr. Chung, who has conducted prostate cancer research
with NASA grant funding since 1995.
Scientists are increasingly
using zero gravity to create three-dimensional organoids in order to
study the interaction of cells within organisms. Experiments in zero
gravity have helped scientists understand development of heart, bone,
muscle, endocrine organs and the locomotion of inflammatory cells and
tumor cells.
"In space, we are able to
create a ‘micro-environment’ that very closely resembles what happens
at the cellular level in our bodies," says Dr. Chung.. "Zero gravity
provides the opportunity to analyze the ‘cross talk’ between cells because
they will grow under a low shearing force and they are not in contact
with other solids, including plastic or glass, which can inhibit or
modulate growth factors."
Previous experiments indicate
that under these conditions, the organoid may grow to be 0.5 to 2.5
centimeters in diameter, which is not possible in earth’s gravity. Dr.
Chung will use this three-dimensional organoid to better understand
the basic molecular process that occurs between cancer cells and their
environment.
In an earlier study, Dr.
Chung and his team had been able to permanently program genotypic and
phenotypic changes into prostate cancer cells through specific cellular
interaction between prostate or bone stromal cell lines. The NASA flight
experiment will study alterations of the cell activity under zero gravity.
In addition to growing the organoid during the mission, investigators
will recover cells and media from the space flight for future behavioral,
genetic and gene expression studies back on earth. Researchers will
study prostate cancer cells’ ability to migrate, invade, and respond
to hormones and drugs after the shuttle returns to earth, and results
will be compared with prostate cancer specimens obtained from patients.
Mahul Amin, MD, associate professor of Pathology and Urology in the
Emory University School of Medicine, will provide the clinical samples
of prostate cancer and bone stroma cells for this experiment.
"We have to remember that
cancer is not just a cell," says Dr. Chung, "it is an organ that is
comprised of cancer cells, blood vessels, fibromuscular stroma, neural
and inflammatory cells. We don’t understand how cancer cells compartmentalize
themselves locally and why and when they metastasize. We are working
to recreate cancer in a microenvironment to better understand how it
works. Zero gravity provides us with an attractive opportunity in which
to do this."
The combination of prostate
cancer cells and healthy bone stroma cells is important because of the
high rate of bone metastasis among prostate cancer patients. Nearly
90 percent of all prostate cancer patients who die of this disease have
bone metastasis.
NASA also has an interest
in this project as the space program continues to develop and as the
space station is built. By providing a true zero-gravity environment
in which experiments can be conducted, NASA is also providing an opportunity
to use space as a laboratory. A NASA Flight Research Program Overview
lists one of the research goals as: "To study the role of gravity in
technological processes, building a scientific foundation for understanding
the consequences of gravitational environments beyond Earth’s boundaries."
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