Estrogen decreases expression of chemokine receptors, and suppresses chemokine bioactivity in murine monocytes.

Problem: We propose that the ability of estrogen exposure to increase the probability of a woman developing breast cancer may be related to decreased chemokine activity and suppression of immune surveillance in mammary tissue. The present study was conducted to determine whether estrogen could decrease monocyte bioactivity through alteration of chemokine receptor expression.

Method Of Study: We examined the effect of estrogen and tamoxifen on the expression of the chemokine receptors CCR2 and CXCR3 on murine monocytes treated in culture and in vivo.

Estrogen decreases chemokine levels in murine mammary tissue: implications for the regulatory role of MIP-1 alpha and MCP-1/JE in mammary tumor formation.

Estrogen contributes to the development of breast cancer through mechanisms that are not completely understood. Estrogen influences the function of immune effector cells, primarily through alterations in cytokine expression. Chemokines are proinflammatory cytokines that attract various immune cells to the site of tissue injury or inflammation, and activate many cell types, including T lymphocytes and monocytes.