Levonorgestrel inhibits proliferation and induces apoptosis in uterine leiomyoma cells

The role of levonorgestrel intrauterine systems in the treatment of symptomatic fibroids

Uterine fibroids are considered to be the most frequently occurring tumours in females. The majority of fibroids do not require any treatment. When symptomatic, the major ailments include abnormal uterine bleeding, painful menstruation, pelvic pressure or pain, urinary problems, constipation, infertility, and recurrent pregnancy loss. Surgery remains a mainstay of symptomatic uterine fibroids therapy; however, minimally-invasive techniques and pharmacological management have become more available. The levonorgestrel intrauterine system (LNG-IUS) is a T-shaped device with a vertical stem containing a reservoir of levonorgestrel and is widely known for its contraception effect. Moreover, the non-contraceptive benefits of the LNG-IUS have been previously confirmed by numerous studies. LNG-IUS causes reduction of the duration and the amount of menstrual bleeding, with minimal side effects due to release of hormones at the targeted organ. Currently, results from systematic reviews show that LNG-IUS may be an effective and safe treatment for symptomatic uterine fibroids in premenopausal women. However, further studies are required to consolidate the usage of LNG-IUS in the treatment of symptomatic uterine fibroids.

Morphological and Ultrastructural Changes in Human Endometrium Following Low-Dose Levonorgestrel Contraceptive Intrauterine Systems (LNG-IUS-12) 13.5 mg

OBJECTIVE

To study the effect of low-dose levonorgestrel contraceptive intrauterine systems (LNG-IUS-12) on endometrial morphology and ultrastructure.

METHODS

Twenty seven women who desired contraception were inserted LNG-IUS-12. Endometrial biopsies were collected during the late proliferative phase of the cycle before (control) and after the use of the LNG-IUS for 36 months. The changes of morphology and ultrastructure of endometrium tissue were observed by light microscope and transmission electron microscope.

RESULTS

After 36 months of use, the endometrial gland reduced in number and some were atrophic. A decidual change of stroma was present. Electronic microscopy demonstrated the presence of low columnar, karyopyknosis, and chromatin margination in the glandular epithelial cell. Some vacuolar degeneration in partial mitochondria and rough endoplasmic reticulum presented light extension. Changes could be concluded as cell inhibition of proliferation.

CONCLUSIONS

The low-dose levonorgestrel-releasing intrauterine systems has a suppressive effect on endometrium that is similar to LNG-IUS.

Effects of miRNA-197 overexpression on proliferation, apoptosis and migration in levonorgestrel treated uterine leiomyoma cells

BACKGROUND/AIMS

Uterine leiomyoma is the ahead benign tumor of the female genital tract, which resulted in menstrual abnormalities, recurrent pregnancy loss, and other serious gynecological disorders in women. Recently, as the process of exploring the brief molecular mechanisms of tumorgenesis, microRNAs (miRNAs) have attracted much more attention.

METHODS

In this study, we first confirmed that microRNA-197 (miR-197) was down-regulated significantly in human uterus leiomyoma by quantity real-time polymerase chain reaction, compared to normal uterus myometrium. Then we observed the potential effects of miR-197 overexpression on human uterus leiomyoma cells by cell counting kit 8, wound healing assay, and flow cytometric assessment separately.

RESULTS

The data showed that miR-197 could inhibit cell proliferation, induce cell apoptosis, and block cell migration in vitro. Coincidently, levonorgestrel (LNG), a well-known uterus leiomyoma therapy, could induce miR-197 expression in human uterus leiomyoma cells, and over-expression of miR-197 showed a synergy effect on human uterus leiomyoma cell proliferation and apoptosis with LNG.

CONCLUSION

In this study, the data showed that miR-197 could play an anti-oncogenic role in human uterus leiomyoma cells, and cooperate with LNG on the cell proliferation and apoptosis, which suggested that miR-197 might be a potential target and provided database for clinical treatment.

Levonorgestrel-releasing intrauterine system use in premenopausal women with symptomatic uterine leiomyoma: a systematic review

A systematic review is done to determine the efficacy and safety of levonorgestrel-releasing intrauterine systems as a treatment using in premenopausal women with symptomatic uterine leiomyoma. We searched the Medline, Central and ICTRP databases for all articles published from inception through July 2013 that examined the following outcomes: uterine volume, uterine leiomyoma volume, endometrial thickness, then menstrual blood loss, blood haemoglobin, ferritin and hematocrit levels, treatment failure rate, device expulsion rate, hysterectomy rate and side effects. From 645 studies, a total of 11 studies met our inclusion criteria with sample sizes ranging from 10 to 104. Evidence suggested that levonorgestrel-releasing intrauterine systems could decrease uterine volume and endometrial thickness, significantly reduce menstrual blood loss, and increase blood haemoglobin, ferritin and hematocrit levels. There was no evidence for decreasing uterine leiomyoma volume. There were no adverse effects on the ovarian function except for ovarian cysts. Device expulsion rates were low, which associated with leiomyoma size (larger than 3cm) but not with leiomyoma location. Irregular bleeding/spotting was observed at the beginning of the follow-up period and then decreased progressively. Results of this systematic review indicate that levonorgestrel-releasing intrauterine systems may be effective and safe treatment for symptomatic uterine leiomyoma in premenopausal women.

Matrix production and remodeling as therapeutic targets for uterine leiomyoma

Uterine leiomyoma, commonly known as fibroids, is a benign neoplasm of smooth muscle in women. The incidence of clinically symptomatic fibroids in reproductive-age women is approximately 20 %, with nearly 80 % of black women suffering from this condition. Symptoms include severe pain and hemorrhage; fibroids are also a major cause of infertility or sub-fertility in women. Uterine leiomyoma consist of hyperplastic smooth muscle cells and an excess deposition of extracellular matrix, specifically collagen, fibronectin, and sulfated proteoglycans. Extracellular matrix components interact and signal through integrin-β1 on the surface of uterine leiomyoma smooth muscle cells, provide growth factor storage, and act as co-receptors for growth factor-receptor binding. ECM and growth factor signaling through integrin-β1 and growth factor receptors significantly increases cell proliferation and ECM deposition in uterine leiomyoma. Growth factors TGF-β, IGF, PDGF, FGF and EGF are all shown to promote uterine leiomyoma progression and signal through multiple pathways to increase the expression of genes encoding matrix or matrix-modifying proteins. Decreasing integrin expression, reducing growth factor action and inhibiting ECM action on uterine leiomyoma smooth muscle cells are important opportunities to treat uterine leiomyoma without use of the current surgical procedures. Both natural compounds and chemicals are shown to decrease fibrosis and uterine leiomyoma progression, but further analysis is needed to make inroads in treating this common women's health issue.

Uterine leiomyoma: available medical treatments and new possible therapeutic options

CONTEXT

Uterine leiomyomas (fibroids or myomas) are benign tumors of the uterus and are clinically apparent in up to 25% of reproductive-age women. Heavy or abnormal uterine bleeding, pelvic pain or pressure, infertility, and recurrent pregnancy loss are generally associated with leiomyoma. Although surgical and radiological therapies are frequently used for the management of this tumor, medical therapies are considered the first-line treatment of leiomyoma.

EVIDENCE ACQUISITION AND SYNTHESIS

A review was conducted of electronic and print data comprising both original and review articles on pathophysiology and medical treatments of uterine leiomyoma retrieved from the PubMed or Google Scholar database up to June 2012. These resources were integrated with the authors' knowledge of the field.

CONCLUSION

To date, several pathogenetic factors such as genetic factors, epigenetic factors, estrogens, progesterone, growth factors, cytokines, chemokines, and extracellular matrix components have been implicated in leiomyoma development and growth. On the basis of current hypotheses, several medical therapies have been investigated. GnRH agonist has been approved by US Food and Drug Administration for reducing fibroid volume and related symptoms. In addition, the FDA also approved an intrauterine device, levonorgestrel-releasing intrauterine system (Mirena), for additional use to treat heavy menstrual bleeding in intrauterine device users only. Currently, mifepristone, asoprisnil, ulipristal acetate, and epigallocatechin gallate have been shown to be effective for fibroid regression and symptomatic improvement which are all in clinical trial. In addition, some synthetic and natural compounds as well as growth factor inhibitors are now under laboratory investigation, and they could serve as future therapeutic options.

The role of progesterone signaling in the pathogenesis of uterine leiomyoma

Uterine leiomyomas are benign tumors that originate from the myometrium. Evidence points to ovarian steroid hormones, in particular, progesterone as major promoters of leiomyoma development and growth. While progesterone action in leiomyomas involves the classical nuclear receptor effects on gene regulation, there is growing evidence that signaling pathways are directly activated by the progesterone receptor (PR) and that PR can interact with growth factor signaling systems to promote proliferation and survival of leiomyomas. Studies investigating the genomic and non-genomic actions of PR and its role in leiomyoma growth are summarized here. Studies testing various selective progesterone receptor modulators for the treatment of leiomyomas are also highlighted. An increased understanding of the mechanisms associated with progesterone-driven growth of leiomyomas is critical in order to develop more efficient and targeted therapies for this prevalent disease.

Etiology, diagnosis, and management of uterine leiomyomas

Uterine leiomyomas are the most common benign gynecologic tumors. While the true etiology of leiomyomas remains unknown, their origin is thought to be multifactorial including genetic, hormonal, and tissue growth factor variations. Leiomyomas are predominantly found in women of reproductive age and are the leading indication for hysterectomy worldwide. Menstrual irregularities, pain, and fertility difficulties may arise from leiomyoma presence, although many women remain asymptomatic. Diagnosis can be made via ultrasound or magnetic resonance imaging, when precise mapping of the tissue is needed. Many treatment options are available ranging from surgical to medical and should be chosen depending on symptom severity, number and size of leiomyomas, patient age, fertility desires, and patient preferences. The objective of this article is to present a practical clinical perspective on uterine leiomyomas and an overview of contemporary treatment options.