The clinical and experimental research on the treatment of endometriosis with thiostrepton.

BACKGROUND/OBJECTIVE: Forkhead Box M1 (FOXM1) is frequently activated in tumors. We studied the expression and the possible mechanism of FOXM1 and evaluated the effects of thiostrepton in an endometriotic rat model.

STUDY DESIGN: This was a randomized study in a rat model of endometriosis. Fifty female Wistar rats were surgically induced with endometriosis. After 4 weeks of observation, twenty and thirty rats were randomly allocated to an ovariectomized (OVX) group and a treatment group, respectively. The OVX group was ovariectomized and randomly divided into an OVX-estrogen group and a control (OVX -oil) group. All rats were allowed a resting period of 3 days prior to any operation. The rats in the estrogen group were given estradiol (20 µg/kg, 0.1 ml /d), while the control group was treated with an equivalent amount of sesame oil. Every group was injected with subcutaneous injection for 7 days. The treatment group was randomly divided into three groups to receive the following: TST at 150 mg/kg, ip.; TST at 250 mg/kg, ip.; or sterile normal saline, ip. The groups received these dosages every 2 days for 2 weeks. Lesion growth, histological examination, and protein expression were subsequently analyzed using caliper measurement, histology, immunostaining, and Western blot after each rat received an injection in its own group.

RESULTS: Our results showed that FOXM1 is enrich in nucleus of an ectopic endometrium when compared with an eutopic uterus. Furthermore, we found that an ERK/FOXM1/matrix metalloproteinase-9 (MMP9) signaling pathway might result in the establishment and development of endometriosis. Finally, a thiostrepton concentration dependently reduced the expression of FOXM1, MMP9 and Bcl-2 in endometriotic lesions of the treated rats. Statistical significance was accepted for a value of P < 0.05 .

CONCLUSION: We postulate that thiostrepton could inhibit the endometriotic lesions, at least in part, by decreasing the FOXM1 expression and exerting a pro-apoptotic effect. We reported for the first time that FOXM1 expresses in experimental endometriosis rat and thiostrepton may also be suitable for the administration of endometriosis by inhibiting the growth of endometriotic implants. More studies are needed to further evaluate thiostrepton's effect.