How Gum Disease Can Lead to Breast Cancer
The bacteria Fusobacteria nucleatum is usually commensal, living on our gums without causing problems except for occasional gum disease. Although it appears to be a fairly harmless microbial hitchhiker, it is actually implicated in a number of diseases ranging from appendicitis to Alzheimer’s to colorectal cancer. Now, new research published in Cellular communication and signaling is connecting F. nucleatum to breast cancer.
“The takeaway is that this oral microbe can reside in breast tissue and there is a link between this pathogen and breast cancer,” study author Dipali Sharma of Johns Hopkins said in a statement.
Using genetically engineered mice to produce human breast tissue as well as human breast cancer cells, Sharma and his team found that exposure to F. nucleatum caused too much multiplication and transformation of breast cells. This activity was accompanied by inflammation and DNA damage.
Read more: “Young and healthy and waiting to get cancer”
Cells with BRCA1 Breast cancer mutations were particularly vulnerable to the bacteria. These cells overexpress a sugar on the cell surface that serves as a sort of molecular welcome mat, allowing bacteria to bind and enter the cell. Once inside, F. nucleatum acted like a bull in a china shop, damaging DNA and activating DNA repair pathways can lead to errors.
Disturbingly, even brief exposure increased the expression of a protein called PKcs, linked to tumor cell migration, invasion and resistance to chemotherapy. Once inside the cells, the bacteria was able to persist despite multiple cell divisions, thereby amplifying tumor promotion.
“Our results reveal a link between oral microbes and breast cancer risk and progression, particularly in genetically predisposed individuals,” Sharma said. “Nothing happens in isolation. The findings suggest that multiple risk factors combine to F. nucleatum acting as an environmental factor that can cooperate with inheritance BRCA1 mutations to promote breast cancer and tumor aggressiveness.
Does this mean poor oral health increases your risk of breast cancer?
Sharma says further study is needed before we can make final decisions. In the meantime, this is all the more reason to make sure you brush your teeth twice a day.
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