Targeting ERβ to fight melanoma: a new valid approach?

The impact of sex steroids and their cognate receptors in many human cancers has been almost neglected for many years. Gender disparities in melanoma, with a female advantage in its incidence and outcome have been reported. However, the molecular aspects of these findings remain still pending, with few reports so far collected on the role of estrogen receptors (ERs), alpha (ERα) or beta (ERβ), or G-protein coupled estrogen receptor (GPER) in this cancer. ERs both mediate estrogen signaling through genomic or non-genomic mechanism, which might cooperate each other to regulate a range of responses in target tissues and human cancers. The subsequent discovery that an orphan GPCR (GPR30, then renamed GPER) is required for rapid estrogen signaling opened new perspectives in estrogen biology and hormone-dependent cancers [3]. ERβ can be detected in benign nevi, pre-malignant and malignant melanocytic lesions. As such, it might represent a hallmark of melanoma progression. A role for GPER has been also proposed in differentiation and growth inhibition of melanoma cells, as well as their susceptibility to immune clearance. GPER increased expression is correlated with reduced overall survival (OS) in melanoma patients.