Effects of Aromatase Inhibitor on Expressions of Survivin and Caspase-3 in the Ectopic Focus of Rat Model with Endometriosis

Objective: To explore the effect of aromatase inhibitor on the expressions of Survivin and Caspase-3 in ectopic focus of rat model. Methods: The rat model of endometriosis(EMs)was made by autologous transplantation of endometrium. The shape and size of the ectopic foci in abdominal cavity were observed and measured after 3 weeks. Rats were then randomly divided into two groups ( twenty in each), letrozole group(A group)and model group as the control (B group). After 4 weeks of administration, the endometrial histological changes were observed in A group, B group and the normal endometrium group (C group). The expression levels of Survivin and Caspase-3 were assessed by immunohistochemical staining in ectopic endometrium and normal endometrium. Results: The rat model of EMs was successfully established. The size of ectopic focus was significantly reduced after 4 weeks of treatment compared with that of before treatment in A group(P 0.05). Both Survivin and Caspase-3 were expressed in endometrial glandular epithelial cells, locating in cytoplasm. Results showed that the positive rate of Survivin was lower in A group and C group than that of B group (P 0.01). The positive rate of Caspase-3 was higher in A group and C group than that of B group (P 0.01), but there was no significant difference in positive rates of Survivin and Caspase-3 between A group and C group (P 0.05). The expression of Survivin was negatively correlated with that of Caspase-3(rs =-0.538,P 0.05). Conclusion: The aromatase inhibitor can inhibit the growth of ectopic focus and Survivin expression, and increase the expression of Caspase-3 in rat ectopic endometrial lesions. The results may offer theoretical foundation for clinical application of letrozole in treatment of EMs.