Nongenomic actions of estrogens and xenoestrogens affecting endocrine cancer cells

Estrogens act via multiple membrane-associated receptors (α, β, and GPR30) to mediate diverse rapid signaling cascades affecting functional endpoints in both normal and cancer cells. The mitogen-activated protein kinases are a summative signaling node that integrates upstream signaling cascades into responses for major functional cellular outcomes such as proliferation, migration, differentiation, and death. These responses are complex; they oscillate with time, as well as fluctuate up and down with increasing ligand concentration (hormesis). Nonphysiologic estrogenic compounds also use these receptors and signaling systems, but do so imperfectly, causing disruptions to both the phasing and dose-responsiveness of physiologic estrogens. Disruptions to the signaling of different physiologic estrogens could cause life stage-specific tissue malfunctions or cancer vulnerabilities.