When people talk about estrogen receptor-positive (ER-positive) tumors, they’re talking about ER alpha, which was discovered about 30 years ago. Scientists have known about its mysterious sister molecule, ER beta, for more than a decade. But its role in cancer is still unclear. “These questions are burning, and the jury’s still out,” says Gokul Das, PhD, Assistant Member, Pharmacology and Therapeutics, at Roswell Park.
 
Das may have found a way to answer them. He is using a molecular genetic technique called RNAi-silencing to look at what happens in breast cancer cells when the ER beta gene is shut down; when the ER alpha gene is silenced; or when both genes are inactive. The behavior of the cells’ genomes in each scenario will help Das and his colleagues understand more fully how ER beta might play a role in the development of breast cancer. Roswell Park donations are providing needed funds for the research.

Through a collaboration with Steven Gill, PhD and Michael Buck, PhD of the Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, Das and his team are analyzing massive amounts of data on thousands of genes. He also is working with Cornell University to research how ER beta controls the production of ribonucleic acid, or RNA (the messenger molecule DNA uses to instruct a cell to make proteins), from specific genes in the breast cancer cell genome. 

Understanding the role of ER beta could allow oncologists to classify breast cancers more precisely, and to tailor treatment more effectively. ER beta’s function may also provide clues to treating other cancers, because it is expressed in tissues beyond the breast, such as the lung and prostate gland.