Investigational drugs for endometriosis

In Vitro and In Vivo Effects of Tumor Suppressor Gene PTEN on Endometriosis: An Experimental Study

BACKGROUND Endometriosis can cause dysmenorrhea and infertility. Its pathogenesis has not yet been clarified and its treatment continues to pose enormous challenges. The protein tyrosine phosphatase (PTEN) gene is a tumor suppressor gene. The aim of this study was to investigate the role and significance of PTEN protein in the occurrence, development, and treatment of endometriosis through changes in apoptosis rate, cell cycle, and angiogenesis. MATERIAL AND METHODS PTEN was overexpressed and silenced in lentiviral vectors and inserted into primary endometrial cells. The changes in cell cycle and apoptosis in the different PTEN expression groups were evaluated using flow cytometry. Vessel growth mimicry was observed using 3-dimensional culture. A human-mouse chimeric endometriosis model was constructed using SCID mice. Hematoxylin and eosin staining and immunohistochemistry were used to detect pathological changes in ectopic endometrial tissues and the expression of VEGF protein in a human-mouse chimeric endometriosis mouse model. RESULTS PTEN overexpression significantly increased apoptosis and inhibited the cell cycle compared with the silenced and control groups. Furthermore, cells expressing low PTEN levels were better able to undergo vasculogenic mimicry, and exhibited significantly increased angiogenesis compared to cells overexpressing PTEN. We found that ectopic foci were more easily formed in the endometrial tissue of SCID mice with low PTEN expression, and the VEGF expression in this group was relatively high. CONCLUSIONS PTEN inhibits the occurrence and development of endometriosis by regulating angiogenesis and the apoptosis and cell cycle of endometrial cells; therefore, we propose that the PTEN gene can be used to treat endometriosis.

Dysmenorrhea in adolescents and young adults: an update on pharmacological treatments and management strategies

INTRODUCTION

Dysmenorrhea is the most common gynecologic complaint among adolescents/young adults. Dysmenorrhea is usually primary and is associated with normal ovulatory cycles and with no pelvic pathology. Potent prostaglandins and potent leukotrienes play an important role in generating primary dysmenorrhea symptoms. Adolescents/young adults with severe dysmenorrhea symptoms may have pelvic abnormalities, such as endometriosis or uterine anomalies (secondary dysmenorrhea).

AREAS COVERED

This review provides an update on treatments and management strategies of dysmenorrhea in adolescents/young adults. Medical literature articles were retrieved using a Medline search on primary and secondary dysmenorrhea. Original articles from peer-reviewed journals were selected based on relevance.

EXPERT OPINION

Treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) is the preferred initial treatment for dysmenorrhea in nonsexually active adolescents/young adults. Adolescents/young adults with symptoms that do not respond to NSAIDs for three menstrual periods should be offered hormonal treatment, such as combined estrogen and progestin oral contraceptive pills (OCPs), for three menstrual cycles. If dysmenorrhea does not improve within 6 months of NSAIDs and OCPs, a laparoscopy is indicated to look for endometriosis, which is the most common reason for secondary dysmenorrhea.

Comparison of the effects of cetrorelix, a GnRH antagonist, and leuprolide, a GnRH agonist, on experimental endometriosis

AIM

In the present study, we aimed to compare the effects of cetrorelix and leuprolide on endometriosis.

METHODS

This randomized, placebo-controlled, single-blind, experimental study was performed on 45 Wistar adult female rats in the Experimental Surgery Laboratory at Ondokuz Mayis University. After the peritoneal implantation of endometrial tissue, rats were randomized to three equal intervention groups: (i) control group, (ii) leuprolide group, and (iii) cetrorelix group. Six weeks later, following implant volume measurements (volume-1) by performing a second laparotomy, saline (0.1 cc/rat) was administered subcutaneously to the control group once a week, leuprolide (0.075 mg/kg) subcutaneously to the leuprolide group twice at 4-week intervals and cetrorelix (0.001 mg/rat/day) subcutaneously to the cetrorelix group for 8 weeks. At the end of the treatment, by performing a third laparotomy, implant volumes were remeasured (volume-2) and implants were totally excised for histopathological examination. The volume-1 and volume-2 values within the groups, and stromal and glandular tissue scores between the groups were compared.

RESULTS

In both the leuprolide group and the cetrorelix group, volume-2 as compared to volume-1 had significantly reduced (P < 0.01, P < 0.01 respectively), while there was no significant volume change in the control group (P > 0.05). In this group, when compared with the control group, glandular and stromal tissues had significantly lessened (P < 0.01, P < 0.01 respectively).

CONCLUSION

Leuprolide and cetrorelix were found to have similar efficacy in the regression of both the size and the histological structure of experimental endometriotic implants.

New drugs in development for the treatment of endometriosis

Endometriosis is a common and enigmatic disease causing pelvic pain and infertility. Current treatment is mainly based on the use of surgery and ovarian suppressive agents. There is in particular the need for new therapeutic options able to allow a normal menstrual cycle to occur and also consent pregnancy. In the present review, we aimed to give a concise and practical overview in order to allow the clinician to clearly understand the level of development of these drugs. We have presented only treatments supported by in vivo researches with a special attention to studies in humans. Results show appealing new possibilities are emerging from agents counteracting the endometriosis-associated inflammation. Recent data also suggests that there is still the opportunity to refine the use of already available agents.