A new study has found that a drug normally used to treat diabetes may be effective against a particularly deadly form of breast cancer. Researchers found that a metabolic enzyome called AKR1B1 drives an aggressive form of breast cancer and could be used to combat it.
The Chinese study found that the drug, when used on mice infected with a "basal-like" triple-negative breast cancer saw inhibited tumor growth when the diabetic drug epalrestat was introduced.
About 15-20 percent of breast cancers are "basal-like" in classification as part of the triple-negative subtype of cancer. This is a particularly aggressive form of breast cancer and difficult to treat. Targeted therapies have so far proven ineffective and the cancer is often fatal.
When basal-like cancers commence, studies have shown, a process called epithelial-mesenchymal transition (EMT) has the cancer cells becoming more motile with stem cell-like properties. This is why they're resistant to treatments and why they're so readily able to grow as a tumor.
What researchers found was the a metabolic enzyme called AKR1B1 is crucial to the EMT process.
This enzyme, Zhejiang University School of Medicine researchers learned, is elevated in those with basal-like and triple-negative breast cancers and has already been associated with increased rates of metastasis and shorter survival in other studies.
AKR1B1 is also associated with elevated Twist2 through a lipid called F2 to signal pathways for cell mutation. This combination is called a "feedback loop." This feedback loop is crucial to the EMT process and interrupting it can greatly inhibit the cancer's growth.
What the researchers found is that the feedback loop for EMT is interrupted by the introduction of epalrestat, a common diabetes drug used in Japan and available in other markets globally.
"Since epalrestat is already on the market and has no major adverse side effects, our study provides a proof of principle that it could become a valuable targeted drug for the clinical treatment of basal-like breast cancer," the study's author says.