Estrogen receptor beta expression in nevi during pregnancy

Area of Science:

• Dermatology
• Endocrinology
• Reproductive Biology

Background:

• Estrogen levels rise during pregnancy.
• Clinical observations suggest melanocytes respond to estrogen.
• Estrogen receptor beta (ERbeta) is hypothesized to mediate this response in nevi.

Purpose of the Study:

• To investigate ERbeta expression in nevi from pregnant versus non-pregnant women.
• To determine if pregnancy influences ERbeta levels in different nevus types (normal, dysplastic, congenital).
• To assess the relationship between melanocytic atypia and ERbeta expression.

Main Methods:

• Immunohistochemical staining of 212 nevi (normal, dysplastic, congenital) from women aged 18-45.
• Antibodies against estrogen receptor alpha (ERalpha) and ERbeta were used.
• Comparison of ERbeta immunoreactivity between pregnant and non-pregnant groups.

Main Results:

• ERbeta was the predominant estrogen receptor in all nevus types; ERalpha was not detected.
• Normal nevi showed significantly higher ERbeta positivity during pregnancy in both epidermal and dermal nevocytes.
• Increased ERbeta was observed in atypical nevi within the epidermis, but not further elevated during pregnancy.
• Congenital nevi from pregnant women had significantly lower ERbeta compared to normal and dysplastic nevi from pregnant women.

Conclusions:

• Nevi possess the capacity for estrogen responsiveness, primarily mediated by ERbeta.
• Pregnancy and degree of melanocytic atypia are associated with enhanced ERbeta expression.
• Congenital nevi exhibit a unique response to pregnancy, with decreased ERbeta, suggesting distinct melanocyte behavior.