Alcohol may Encourage Cancer Progression

Reported October 29, 2009

(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