March 7 (UPI) -- Researchers in China have discovered a metabolic enzyme inhibitor called epalrestat, used to treat complications from diabetes, could be effective in fighting a deadly form of breast cancer.
The metabolic enzyme AKR1B1 promotes the growth of the deadly form of basal-like and triple-negative breast cancer.
Between 15 and 20 percent of all breast cancers are basal-like, which is particularly aggressive and falls into the triple-negative breast cancer subtype. Currently, there are no effective treatments for this form of breast cancer, which is often fatal.
Basal-like breast cancer is more aggressive due to a process called epithelial-mesenchymal transition, or EMT, a process where cancer cells become more capable of motion and gain stem cell-like properties allowing them to resist treatment and metastasize.
Researchers discovered levels of AKR1B1 were significantly higher in basal-like and triple-negative breast cancers, which was linked to increased rates of metastasis and death.
Conversely, researchers found that knocking down AKR1B1 inhibited the growth and metastasis of tumors in basal-like breast cancer cells injected into mice.
The study also revealed epalrestat, a drug used to treat peripheral diabetic neuropathies, inhibits AKR1B1 and can block the growth and metastasis of basal-like breast cancer cells.
"Our data clearly suggests that AKR1B1 overexpression represents an oncogenic event that is responsible for the aggressive behaviors of basal-like breast cancer cells," Chenfang Dong, a researcher at the Zhejiang University School of Medicine in Hangzhou, China, said in a press release. "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 was published in The Journal of Experimental Medicine.