Estrogen receptor

Class

small molecule

Notes

original target text: Estrogen receptor degrader

The estrogen receptor (ER) is a nuclear hormone receptor found inside cells, particularly in breast, uterine, and bone tissue. When the hormone estrogen binds to it, the receptor changes shape, moves into the nucleus, and attaches to DNA to switch on genes that drive cell growth and division. In a large share of breast cancers, this signaling pathway becomes a primary driver of tumor growth, making the receptor an attractive drug target. Selective estrogen receptor degraders (SERDs) are small molecules designed to bind the receptor and promote its breakdown by the cell's protein disposal machinery, reducing the total amount of receptor available regardless of estrogen levels. This differs from older strategies that simply block the hormone from binding or lower estrogen production throughout the body. By eliminating the receptor itself, degraders aim to shut down its activity more completely and to remain effective even when tumors develop mutations that make the receptor active without estrogen. This mechanism is broadly relevant to hormone receptor-positive breast cancer and is being explored in other estrogen-driven conditions.