Proteins and toxins produced by the body’s own immune system could prove to be powerful weapons in the fight against malignant mesothelioma.
Manipulating the immune system to fight cancer is known as immunotherapy. One type of immunotherapy is utilizing natural immunotoxins, or cell killers, produced by the white blood cells
to attack tumors. Preliminary data shows that a protein produced by
these cells called interleukin-4 or IL-4, may have potent
cancer-fighting properties. Researchers with the Pacific Heart Lung
& Blood Institute in California are planning studies to test the
toxin’s value as a way to combat mesothelioma.
Their first
challenge will be to produce enough IL-4 to conduct tests. When enough
of the immunotoxin can be synthesized according to FDA standards, the
researchers plan to test it in combination with chemotherapy,
hyperthermia and interferon therapy using mesothelioma cells grown in
the laboratory. If the results of the laboratory studies (in vitro)
show promise, the teams will conduct studies of IL-4 in animals (in vivo) and eventually in human subjects.
Mesothelioma, a
rare cancer that attacks the tissues surrounding the lungs and other
organs, is extremely difficult treat and survival beyond one year is
uncommon. According to the PHLBI website, if these planned trials prove
the efficacy of IL-4, it ‘could be a key to significant progress toward
a cure for this dreaded disease’.
Another substance produced by the immune system, interferon, has also shown promising results against mesothelioma in studies conducted at UCLA. Interferons
are messenger proteins that are normally produced to fight certain
kinds of infections. PHLBI researchers believe that, like immunotoxins,
interferons may also play a role in fighting abnormal cells like cancer cells,
by inhibiting their ability to form blood vessels. In high does, they
have already been shown to help keep melanoma cancer from recurring.
Plans are in place
for upcoming trials to combine interferon with other therapies such as
hyperthermia and immune stimulating cytokines to treat mesothelioma
cells in the laboratory. Eventually, interferon may even be combined
with a COX-2 inhibiting drug such as Celebrex as a ‘maintenance therapy’
to keep mesothelioma tumors in check. As with IL-4, success in the lab
may lead to animal and eventual human testing at UCLA and other centers around the country.
Source:
Mesothelioma
