New finding might mean
cancer has no place to hide(Credit:
Depositphotos/lightsource)
When a malignant tumor invades the body, immune
cells rush to the site to begin to fight it. When that same
tumor spreads throughout the body, however, the cancer cells
become invisible to our immune systems and can metastasize
unencumbered by our natural defenses. Researchers out of the
University of British Columbia (UBC) are on to cancer's tricky
cloaking mechanism though, and their discovery could lead to new
approaches to attacking the disease.
"We discovered a new mechanism that explains how
metastatic tumours can outsmart the immune system and we have
begun to reverse this process so tumours are revealed to the
immune system once again," said Wilfred Jefferies, senior author
of a new study in
Scientific Reports and a professor of medical
genetics and microbiology and immunology at UBC.
The discovery hinges on a protein called
interleukein-33, or IL-33 that's present in primary tumors. When
the tumors emit this protein, it causes another protein complex
known as the major histocompatibility complex (MHC) to activate,
which tags the cancer cells as a bad presence in the body and
guides the immune system to get to work destroying them.
The researchers found that as cancer cells evolve,
however, they might lose the ability to produce IL-33 which, in
effect, allows them to spread throughout the body without
alerting the immune system to their presence. They found that
the loss of IL-33 was present in cancers that start on the
lining of major organs such as the prostate, kidney, lungs and
pancreas, known as epithelial carcinomas.
In the study, when IL-33 was reintroduced to
metastatic cancers, it was found that the immune system was able
to spot them once again.
While the research was done on prostate and kidney
cancer patients, the hope is that testing for IL-33 could at
least help doctors monitor the progression of these and other
kinds of cancer, and at best, lead to new treatment options.