Diet High in Leucine May Fuel Breast Cancer's Drug Resistance

April 18, 2019 denise durgin

April 17th, 2019

BOSTON - About one in eight women in the United States will develop breast cancer in her lifetime. The vast majority of these cancers rely on the hormone estrogen to grow. Estrogen-receptor positive (ER+) breast cancer tumors are frequently treated with the drug tamoxifen, which blocks the hormone's effect on the tumor. However, many tumors eventually become resistant to tamoxifen, allowing cancer to recur or metastasize.

Now, a team of researchers at the Cancer Center at Beth Israel Deaconess Medical Center(BIDMC) has discovered an unexpected relationship between levels of the amino acid leucine and the development of tamoxifen resistance in ER+ breast cancer. Led by Senthil K. Muthuswamy, PhD, the researchers further identified a key protein that imports leucine into cells and modulates sensitivity to tamoxifen in ER+ cells in the lab setting. The findings, published today in the journal Nature, reveal a potential new strategy for overcoming resistance to endocrine drugs in ER+ breast cancer patients.