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October 17, 2007
By Fabienne Heimgartner,
Checkbiotech
Almost everyone has heard of, or
experienced, the side effects of cancer chemotherapy. Now a
laboratory at Thomas Jefferson University in Philadelphia has
described a plant- derived protein, which could soon be used as
an anti- cancer vaccine, thus reducing the number of people who
would need chemotherapy.
Colon cancer, also called colorectal cancer, includes malignant
cell growth in the colon, rectum and appendix and is the third
most common form of cancer. Moreover, it is the second leading
cause of cancer-related death in the Western world. The
treatment normally consists of surgery, which is mostly followed
by chemotherapy. Nevertheless, scientists are putting a lot of
effort to find and ameliorate new therapy approaches, such as
immunotherapy.
Scientists in the group around Dr. Hilary Koprowski at the
Biotechnology Foundation Laboratories at the Thomas Jefferson
University in Philadelphia produced a plant-derived, colorectal
cancer antigen, which is a substance that the human body
recognizes as foreign and thus triggers an immune response.
Dr. Koprowski's team inserted the genetic information that can
produce the antigen into tobacco plants. The plants in turn
generated colorectal antigen (EpCAM) in large quantities just
like an assembly line ("Plant-derived EpCAM antigen induces
protective anti-cancer response" Cancer Imunollogy and
Immunotherapy 2007).
To see if these plant-derived proteins could elicit an immune
response, Dr. Koprowksi's group then injected EpCAM into mice.
All of them reacted with the production of EpCAM-specific
antibodies, which could be detected in the serum.
To go one step further, the scientists grafted colorectal cancer
cells into a mouse that does not contain an immune system,
called a nude mouse. Since nude mice do not posses immune cells,
the researchers subsequently injected them with immune cells
capable of producing antibodies to EpCAM. The serum took over
the job of the immune system, and indeed inhibited the growth of
the cancer cells.
Until now, antibodies were mainly produced in mice or microbial
systems, but the data obtained by Dr. Koprowski's team show that
plant-derived antibodies are as good as antibodies produced in
animal cells.
From an economic perspective, the use of plant biotechnology has
clear advantages when compared to mammalian technology such as,
very high production levels and low investment. Plus, plants
offer a more environmentally friendly production method because
they can help reduce greenhouse emissions.
Taken together, Dr. Koprowski's work indicates that plants could
be an important and promising tool to produce antibodies for
anti-cancer vaccination. If enough funding and support is
acquired to run clinical trials on the vaccine, one day, it
might be possible to receive a prescription for an anti-cancer
vaccine.
Fabienne Heimgartner
is a Science Journalist for ACCESS! and is currently gaining her
first work experience as a biologist.
Contact
Prof. Hilary Koprowski
Department of Cancer Biology
Jefferson Medical College
Thomas Jefferson University
233 South 10th Street
Philadelphia, Pennsylvania 19107
United States
Phone: (215) 503-4761
Hillary.Koprowski@mail.tju.edu
Publication
Brodzik et al. Plant-derived EpCAM antigen induces protective
anti-cancer response. Cancer Immunology, Immunotherapy,
published online July 19th 2007
http://www.springerlink.com/content/30j54p613218rk65/ |
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