Vegan Diet Could Treat Aggressive Cancers

Amino acid abundant in meat and fish could open receptors in cancer cells.

A low methionine diet may starve off triple-negative breast cancer cells by depriving them of a crucial amino acid, a recent study suggests.

The study, conducted by the University of Wisconsin Carbone Cancer Center, found that methionine, an amino acid abundant in meat and fish but very low in vegetables and fruits, could open new receptors in particularly aggressive cancer cells.

Triple-negative breast cancer cells lack three receptors most commonly targeted in traditional therapies. In standard breast cancer treatments, estrogen, progesterone, and human epidermal growth factor receptor 2 (HER-2) are targeted, and a receptive antibody binds with them to kill off the cancer cells.

If these receptors are not responsive, like in the case of triple-negative breast cancer, less treatment options become available.

Vincent Cryns, professor of medicine at UW and his team found that low methionine could help increase the vulnerability of these cancer cells.

"We've shown that removing methionine can have a specific effect on a molecular pathway that regulates cell death to increase the vulnerability of cancer cells to treatments that target this pathway," Cryns says. "What's particularly exciting about our findings is that they suggest that a dietary intervention can increase the effectiveness of a targeted cancer therapy."

In trials with triple-negative breast cancer infected mice, lead author Elena Strekalova and the research team found that when deprived of methionine, the cancer cells responded by producing a large amount of the receptor TRAIL-R2. When this receptor becomes active, cancer cells are more susceptible to binding with antibodies, which triggers them to die.

The team found that the combination diet and antibody treatment was far more effective than either treatment alone. It has been known for decades that methionine can be a critical factor in blocking certain types of cancers; this study has set the foundation for future human trials.

This study was published as the highlight study in Clinical Cancer Research, June 2015 edition.