New Targets for Breast Cancer Treatments Could Increase Effectiveness and Reduce Side Effects

There may be a new treatment for breast cancer. Scientists have uncovered new targets for potential intervention in breast cancer, which could eventually increase the effectiveness and reduce the undesirable side effects of current treatments.

About two out of three breast cancers are driven by receptors that bind hormones; when the hormones bind to these receptors in cancer cells, they signal the cancer cells to grow. Yet the progesterone receptor is particularly interesting to researchers therapeutically; it has two activation domains, AF1 and AF2, which are both normally needed for full activation of the receptor. Yet it's possible that small molecules could be used to block the interaction between AF2 and AF1.

That's why scientists decided to take a closer look at the interaction between AF1 and AF2 and the domains of the progesterone receptor. More specifically, the scientists used an advanced technology known as hydrogen-deuterium exchange mass spectrometry (HDX) in order to measure the intricate interactions between the receptors and the activation domains.

"Using hydrogen-deuterium exchange technology, our study pinpoints just how AF2 communicates with AF1-the first evidence of the long-range interaction between these two functional domains," said Patrick R. Griffin, one of the researchers, in a news release. "These findings support further research to look for promising small molecules to block that interaction."

In the future, scientists could potentially develop treatments to help with breast cancer. By learning about the interactions, researchers have stacked the first buildings blocks that they need in order to continue future research. The scientists hope to explore potential new drugs for breast cancer, and also investigate the implications for prostate cancer, another hormone-driven disease.

"Many features of the androgen receptor are similar to progesterone receptor, as they belong to the same subfamily of steroid receptors," said Devrishi Goswami, one of the researchers, in a news release. "It could work the very same way. So these new insights may also help in finding new approaches to treating hormone-therapy-resistant prostate cancer."

The findings are published in the journal Structure.