Gene linked to 70% of ER-negative breast cancer

Researchers have identified a gene associated with 70% of estrogen receptor (ER)-negative breast cancers, a study from the Whitehead Institute for Biomedical Research (Cambridge, Massachusetts) reports.

Investigators used a new technique-RNA interference (RNAi)-based loss-of-function screening-to analyze hundreds of genes at a time, seeking the ones that drive tumor formation and growth. When they injected cancerous cells with genetic material that can deactivate genes, they observed that the gene phosphoglycerate dehydrogenase (PHGDH) was significantly more active than normal in 70% of ER-negative tumors, which are difficult to treat because they don't respond to hormone therapies.

PHGDH catalyzes production of the amino acid serine. Cancer cells with high PHGDH expression have increased serine synthesis; suppressing the gene markedly decreases cell proliferation and serine synthesis in cells with elevated PHGDH expression but not in cells without it.

Possemato R, Marks, KM, Shaul YD, et al. Functional genomics reveal that the serine synthesis pathway is essential in breast cancer. Nature. July 14, 2011. Epub ahead of print.