Researchers at Fox Chase Cancer Center (FCCC) identified a gene involved in the spread of breast cancer that has developed resistance to long-term estrogen deprivation. The research focused on breast cancer cells that had grown resistant to a class of antihormone drugs called aromatase inhibitors (AI).
"Unfortunately, one of the drawbacks to extended use of an AI may be that some of the cancer cells develop resistance to the drug and are able to grow and spread independent of estrogen," says FCCC biochemist Joan S. Lewis-Wambi, Ph.D.
"Our laboratory has developed several AI-resistant breast cancer cell lines and have found that these cells are more invasive than AI-sensitive breast cancer cells. Analyses of gene activity in these AI-resistant cells have shown that they express high levels of genes associated with invasiveness and metastasis."
The researchers found, however, that they could reverse this aggressive behavior by using siRNAs to knock out CEACAM6 (carcinoembryonic antigen-related cell adhesion molecule 6).
"Overall, these findings identify CEACAM6 as a unique mediator of the aggressiveness and spread of AI-resistant breast cancer," Dr. Lewis-Wambi says.
The discovery was reported on April 19 in an oral presentation during the Meeting of the American Association for Cancer Research in Los Angeles.