Dietary supplement in sports drinks may control growth of HER2-positive breast cancer

A team of scientists has found that cyclocreatine, a dietary supplement, may block an avenue for growth for HER2-positive breast cancers. The findings, outlined in a study published Aug. 30 in Cell Metabolism, helped develop a treatment method that reduced cancer growth without toxicity in mice.

“The HER2 receptor tyrosine kinase, which functions as an ‘on’ or ‘off’ switch in cellular functions, is a key driver of breast cancer, and is overexpressed in about a quarter of all breast cancers,” said corresponding author Taro Hitosugi, PhD, a pharmacologist at Mayo Clinic, in a prepared statement. “While drugs such as trastuzumab improved outcomes for some patients with HER2-positive breast cancer, some tumors are or may become resistant to this drug.”

The researchers found that cyclocreatine, a supplement often found in sports drinks, can effectively target the mitochondrial enzyme signaled by HER2. The goal, according to Hitosugi, was to affect mitochondrial energy metabolism to minimize growth by cancerous cells.

This approach was confirmed by injecting mice with patient-derived, trastuzumab-resistant HER2 positive tumors, though researchers noted additional research will be needed to develop effective cyclocreatine-based therapies.

“Mitochondrial creatine kinase 1 may be a new drug target for the treatment of HER2 positive breast cancer,” said Matthew Goetz, MD, director of the Mayo Clinic Breast Cancer research program. “Future clinical trials will be necessary to determine the effectiveness of this drug for HER2 positive breast cancer resistant to standard therapies."