Effect Of Tamoxifen Combined With Mifepristone On Apoptosis, Bcl-2 And Bax Expression And Proliferation In Early Pregnancy Chorionic Villi

Objective: To investigate the effect of tamoxifen combined with mifepristone on apoptosis, bcl-2 and bax expression and proliferation in early pregnancy chorionic villi. To find the possible mechanism of this scheme on shortening the duration of vaginal bleeding after medical abortion. Design: randomized controlled trial.Participants and Methods: Fifty women within 49 days of gestation were randomly divided into two groups. Tamoxifen 120mg combined with mifepristone 150mg was administered orally to one group, followed by misoprostol 600 μ g orally. Placebo combined with mifepristone 150mg was administered orally to another group, followed by misoprostol 600 μ g orally. Chorionic villi discharged were collected and apoptosis was detected by terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end-labelling (TUNEL), expression of bcl-2, bax and ki-67 were detected by immunohistochemical methods. Integrated optical density (IOD) of bcl-2 and bax were detected by using special image analysis software (image pro plus 4.0).Results: (1) Apoptosis was mainly observed in the nuclei of both cytotrophoblasts (C-cells) and syncytiotrophoblasts (S-cells). Compared to control group, the apoptosis index of C-cells and S-cells was significantly increased in treatment group(14.40% ± 7.05%vs9.06% ± 5.04% P<0.01; 9.89%±3.95%vs5.85%±2.15% P<0.01). (2) Bcl-2 was immunolocalizedin the cytoplasm of S-cells, IOD of bcl-2 expression significantly decresased in the treatment group(328.24± 194.20vs682.41 ±237.41 P<0.01);Bax was mainly immunolocalized in the cytoplasm of both C-cells and S-cells, IOD of C-cells and S-cells bax expression significantly increased in the treatment group(1036.18±369.47vs658.78±200.76P<0.01; 1554.28 ±554.20vs988.18 ±301.14 PO.01). (3) Ki-67 was mainly immunocalized in the nuclei of C-cells, and there was no significant difference of ki-67 positive expression ratio between two groups ( 45.19% ± 5.48%vs47.06% ± 6.73% P>0.05; 14.78%±2.71%vsl5.64%±4.64% P>0.05) .(4) Apoptosis in chorionic villi was correlated with bcl-2 expression and bax expression (r = - 0.439 PO.05; r =0.681 PO.01; r =0.770 PO.01).Conclusion: Compared to mifepristone, tamoxifen combined with mifepristone promoted trophoblasts apoptosis. And this effect was associated with bcl-2 and bax expression.