Many forms of cancer are treated with
radiation therapy. However, some cancer
cells have the ability to survive this type of treatment.
cell carcinoma (OSCC) is one of these forms of cancer, and is the reason
why researchers from Kumamoto University in Japan began searching for
methods to combat resistance to radiotherapy.
‘Rather than going after the cancer cells directly, researchers have found a way to control the biological mechanisms that aid in radioresistance.’
Rather than going after
the cancer cells directly, they attempted to find a way to control the
biological mechanisms that aid in radioresistance. This meant looking at
interleukin-6 (IL-6), a cytokine known for signaling the inflammatory
response, and nuclear factor erythroid 2-related factor 2 (Nrf2), which
is a protein that protects against oxidative stress.
Their approach consisted of multiple in vitro experiments on two
different cancer cell samples. One sample was derived from tissue
specimens taken from consenting patients with advanced OSCC who had
undergone chemoradiotherapy (30 Gy total dosage). The other consisted of
human OSCC cell lines which were obtained from the Japanese Collection
of Research Bioresources Cell Bank (Osaka, Japan). These cells were
irradiated with doses of either six or 10 Gy.
The results of the experiments provided evidence that IL-6 provides
protection from radiation therapy to cancer cells through interaction
with the Nrf2-antioxidant pathway.
"This interaction and the resulting
protection from oxidative damage that we have discovered here is very
interesting," said Professor Hideki Nakayama, one of the research group
leaders. "As far as we know, we are the first to discover that IL-6 has
such an effect on the Nrf2-antioxidant pathway. We hope new therapies
that target IL-6 will give us an advantage over many types of
The majority of the experiments performed were in vitro, which is a
limitation of this study. However, research from the same group has
already shown in a mouse model that the immunosuppressive drug
tocilizumab, a drug currently used for rheumatoid arthritis, is
effective against IL-6R as treatment for OSCC. Future research will
attempt to expand on the researcher's idea of reducing the radiation
resistance of cancer.
This research can be found in the British Journal of Cancer