Chapter 6 - Cell-selective breast cancer targeting through estrogen receptors

Abstract

Breast cancer is the foremost cause of death among women worldwide. The estrogen receptors (ERs), a nuclear receptor superfamily member, are closely associated with breast cancer development and therefore serve as an important molecular target for the development of pioneering targeted nanomedicines for breast cancer treatment. Drug targeting at its site of action selectively delivers the anticancer agent to cancer cells and hence avoids contact with healthy cells. This further improves their cytotoxic potential, even in the case of multidrug-resistant cells. A higher level of estrogen involved in the proliferation and growth of breast cancer cells requires overexpression of ER in breast cancers, further representing ER as an attractive target for breast cancer targeting. This chapter focuses on the various aspects of ER targeting strategies including the synthesis of estrogen–drug conjugates, surface modifications of nanocarriers for ER targeting, drug–polymeric conjugates, and antiestrogenic molecule-directed nanotherapeutics. Additionally, a section on breast cancer treatment strategies based on selective agonists and antagonists to ER is included.