Washington, April 19 : US researchers have identified a key gene that may be a marker of breast cancer metastasis, and a possible target for novel treatments for patients suffering from the disease.

The findings by researchers at Fox Chase Cancer Center, presentedduring the 97th Annual Meeting of the American Association for Cancer Research in Loss Angeles, may be helpful for doctors in detecting patients who are at the greatest risk of breast cancer recurrence.

Dr. Joan S. Lewis-Wambi, a biochemist at the centre, says that the research focused on breast cancer cells that had grown resistant to a class of anti-hormone drugs called aromatase inhibitors (AIs).

AIs shut down an enzyme, aromatase, which lets the body produce oestrogen outside the ovaries. These drugs represent one of the newest, most effective forms of hormone therapy for postmenopausal women whose breast cancer tests positive for oestrogen receptors, which means that oestrogen in the body fuels the growth of cancer cells.

“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 oestrogen,” said Dr. Lewis-Wambi.

“Our laboratory has developed several AI-resistant breast cancer cell lines and have found that these cells are very invasive compared to 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,” she explained.

She, however, said that by knocking out the gene called CEACAM6 (carcinoembryonic antigen-related cell adhesion molecule 6) with the help of molecules called “small interfering RNAs”, this aggressive behaviour may be reversed.

“Overall, these findings identify CEACAM6 as a unique mediator of the aggressiveness and spread of AI-resistant breast cancer. This suggests that it might be an important biomarker for metastasis and a possible target for novel treatments for patients with metastatic breast cancer,” Lewis-Wambi said. (ANI)