(Ivanhoe Newswire) -- Although alcohol consumption has been linked to
colon and breast cancer, exactly how this occurs remains unclear. New
understanding of a cellular process provides scientists with some possible
answers.
Epithelial-mesenchymal transition (EMT) -- essential for numerous developmental
processes -- may also be a cellular pathway by which alcohol-induced cancer
cells aggressively metastasize.
Researchers now believe that EMT may promote cancer by turning on signals in
cancer cells that help them leave the main tumor, invade the bloodstream and
spread in the body. EMT may also make cancer cells more resistant to
cancer-killing drugs, and increase the mutation rate in cells which can promote
the spread of cancer cells.
"Alcohol consumption is known to increase the risk of several cancers, including
cancers of the oral cavity, esophagus, liver, colon, rectum, and, in women, the
breast," Christopher B. Forsyth, assistant professor of medicine and
biochemistry at Rush University Medical Center, was quoted as saying. "We also
suspect an association with cancers of the pancreas and lung. However, the
mechanisms by which alcohol increases the risk for these cancers have not been
established. EMT is an active area of cancer research and growing evidence
supports a role for EMT during cancer progression and metastases for several
cancer types but previously not for alcohol-associated cancers."
For this study, the research team collected samples from four alcoholic and four
healthy subjects, all male. They treated colon and breast cancer cell lines with
alcohol, then assessed them for EMT-related changes. They examined the effects
of alcohol on a key EMT transcription factor called Snail, a protein, as well as
on epidermal growth factor receptor (EGFR) signaling, a pathway known to promote
cancer and EMT.
"Our data are the first to show that alcohol turns on cell signals as well as
biomarkers characteristic of EMT in cancer cells," said Forsyth. "We also show
alcohol turns on the EMT pathway in non-cancer intestinal cells, thus supporting
a possible role for alcohol stimulation of EMT in cancer initiation. Thus, our
study supports a possible new mechanism through which alcohol may promote cancer
progression by stimulating EMT. This now provides a new target for therapeutic
intervention for treatment of alcohol-related cancers and for prevention of
alcohol-related cancer metastasis."
SOURCE: Alcoholism: Clinical & Experimental Research, October 26, 2009
