Adenomyosis: evidence for genetic cause

m6A RNA Methylation Regulators Contribute to Eutopic Endometrium and Myometrium Dysfunction in Adenomyosis

Adenomyosis is a prevalent, estrogen-dependent uterine disorder wherein endometrial cells are abnormally present in the myometrium and are surrounded by hyperplastic/hypertrophic smooth muscle. Its etiology is unclear, although endometrial cell invasion into the myometrium has been postulated. RNA methylation, particularly N6-methyladenosine (m6A), plays an important role in regulating various physiological processes and invasive disorders. The goal of this in silico and lab-based experimental study was to explore a possible role for m6A in adenomyosis. Gene expression profiles of both the endometrium and myometrium of women with adenomyosis (cases) and without disease (controls) were obtained from the publicly available Gene Expression Omnibus (GEO) database. In the endometrium, STRING database analysis revealed that METTL3 functions as a "hub" gene of m6A RNA methylation regulators, and the genes involved in m6A regulation, including METTL3, FTO, ZC3H13, and YTHDC1 expression, were significantly decreased in cases versus controls. Functional, co-expression, and correlational analyses of endometrium from cases versus controls revealed decreased total m6A levels, induced by METTL3, and the downstream elevated insulin-like growth factor-1(IGF1) and D-Dopachrome Tautomerase (DDT), with the latter two having known functions in epithelial proliferation and cell migration, which are important processes in the pathogenesis of adenomyosis in endometrium. m6A RNA methylation regulators, including RBM15/15B, ALKBH5, FTO, YTHDF1/2, KIAA1429, HNRNPC, METTL3, ZC3H13, and YTHDC2, were also differentially expressed in the myometrium from cases versus controls. We validated decreased total m6A levels and differential expression of m6A RNA methylation regulators in the myometrium of patients with adenomyosis using qRT-PCR, immunohistochemistry and tissues available from our biorepository. Possible target genes, including cadherin 3(CDH3), sodium channelβ-subunit 4 (SCN4B), and placenta-specific protein 8 (PLAC8), which are involved in cell adhesion, muscle contraction and immune response in the myometrium of adenomyosis patients were also validated. Thus, through extensive public database mining and validation of select genes, this study, for the first time, implicates m6A and its methylation regulators in the pathogenesis of adenomyosis. Follow on functional studies are anticipated to elucidate mechanisms involving m6A and its regulators and down-stream effectors in the pathogenesis of this enigmatic reproductive disorder and potentially identify druggable targets to control its associated symptoms.

Increased expression of p21-activated kinase 4 in adenomyosis and its regulation of matrix metalloproteinase-2 and -9 in endometrial cells

OBJECTIVE

To investigate the expression of p21-activated kinase 4 (Pak4) in both adenomyotic foci and the eutopic endometrium of women with adenomyosis, and whether the activities of matrix metalloproteinases (MMPs)-2 and -9 are regulated by Pak4 in endometrial cells.

DESIGN

Experimental study using human samples and cell lines.

SETTING

University hospital.

PATIENT(S)

Thirty-nine patients with histologic evidence of adenomyosis, and 34 patients with carcinoma in situ of the uterine cervix without adenomyosis or endometriosis.

INTERVENTION(S)

Immunohistochemistry, zymography after transfection with Pak4 small interfering RNA (siRNA), and western blot analyses after nuclear factor kappa-B (NF-кB) inhibitor treatment.

MAIN OUTCOME MEASURE(S)

The Pak4 immunoreactivity of women with vs. without adenomyosis was compared semiquantitatively. The activities of MMP-2 and -9 were analyzed in eutopic endometrial stromal cells and Ishikawa cells after transfection with Pak4 siRNA. The Pak4 expression was evaluated in endometrial cells after treatment with NF-кB inhibitor.

RESULT(S)

Pak4 immunoreactivity was increased in adenomyotic foci and in the eutopic endometrium of women with adenomyosis. Transfection of endometrial cells with Pak4 siRNA led to significant decreases of MMP-2 and -9 activities. In vitro treatment of endometrial cells with tumor necrosis factor-alpha caused a significant increase of NF-кB activation and Pak4 expression, which was obviously decreased by the NF-кB inhibitor pyrrolidinedithiocarbamate.

CONCLUSION(S)

Our results suggest that Pak4 is regulated by NF-кB and that increased Pak4 expression can lead to development of adenomyosis by enhancing the invasiveness of endometrial cells through regulation of MMP-2 and -9 activities.

The pathophysiology of uterine adenomyosis: an update

The diagnosis of adenomyosis using noninvasive techniques such as vaginal ultrasounds and magnetic resonance has clear clinical applications and has renewed the interest in the pathogenesis of uterine adenomyosis. However, the research remains hampered by the lack of consensus on the classification of lesions. Magnetic resonance imaging and transvaginal ultrasound have comparable diagnostic accuracy. Minimal interventional biopsy techniques have recently been introduced. This article reviews human and animal studies and provides an update on the pathophysiology of adenomyosis. Recent views on the pathogenesis and links with endometriosis are discussed.

Future developments in the medical treatment of abnormal uterine bleeding: what can we expect?

New therapies for abnormal uterine bleeding have been slow to reach the marketplace for a variety of reasons. These reasons include the availability of cost-effective therapies already available and the extraordinarily difficult and expensive regulatory barriers emphasizing long-term safety. Common comorbidities like bleeding diatheses, adenomyosis, and leiomyomata further complicate clinical development, necessitating large study samples and making it more expensive. Even the accurate measurement of menstrual blood loss adds an additional hindrance to novel drug development. These obstacles and the currently available therapies will be reviewed in the context of developing new methods for approaching this complicated and prevalent clinical problem.

Adenomyosis: the pathophysiology of an oestrogen-dependent disease

Adenomyosis uteri is a common gynaecological disorder that is characterized by the presence of ectopic endometrial glands and stroma in the myometrium. Although adenomyosis and endometriosis are different diseases, both of them grow and regress in an oestrogen-dependent fashion. Polymorphisms in the oestrogen receptor alpha gene are associated with a risk of adenomyosis. Adenomyotic tissue contains steroid receptors as well as aromatase and sulphatase enzymes. Together with the circulating oestrogen, locally produced oestrogens stimulate the growth of tissue mediated by the oestrogen receptors. Oestrogen metabolism, including the expression pattern of aromatase and the regulation of 17beta-hydroxysteroid dehydrogenase type 2 is altered in the eutopic endometrium of women with endometriosis, adenomyosis, and/or leiomyomas compared to that in the eutopic endometrium of women without disease. In addition to the conventional hormonal treatment with gonadotropin-releasing hormone agonists and danazol, the use of steroid-releasing intrauterine devices may be applicable to clinics.

[Adenomyosis: update on a frequent but difficult diagnosis]

Adenomyosis is a frequent entity, with difficult diagnosis, often obtained by pathological analysis performed after hysterectomy. This condition can cause abnormal uterine bleeding and dysmenorrhea, frequent reasons for consultation and hysterectomy. The development of ultrasonographic and magnetic resonance imaging techniques allow preoperative diagnosis. They also permit the use of hysteroscopic techniques for conservative uterine surgery, and have brought diagnosis and management of this disease to the front of the scene. This article reviews the pathological description of the disease, its epidemiology, clinical presentations, useful and necessary explorations, etiopathogeny and available therapies.

Évolutions physiopathologiques, diagnostiques et thérapeutiques dans la prise en charge de l’adénomyose : revue de la littérature

OBJECTIVE

Adenomyosis is a relatively frequent disease of unknown origin, which is difficult to diagnose. Appropriate treatment for women who want to preserve or improve their fertility remains to be defined.

METHODS

This review summarized the reports found on Medline database about pathophysiology, diagnosis and management of adenomyosis.

RESULTS

Many pathophysiological factors may be involved in the occurrence of adenomyosis: immunological factors, estrogen sulfatase activity, tenascin which is a fibronectin inhibitor and angiogenesis and growth factors such as EGF, VEGF and GM-CSF. Endovaginal ultrasonography seems to be as effective as MRI for the diagnosis of adenomyosis. GnRH agonist decreases symptoms and uterine volume; however, the symptoms reappear after discontinuation of agonist therapy, and side effects limit their prolonged use. Progesterone receptor modulators, anti-progestative and danazol or levonorgestrel-releasing intra-uterine system have been used as therapeutic modalities for adenomyosis, but the lack of controlled studies make their efficacy difficult to quantify. Some women with superficial adenomyosis may theoretically benefit from hysteroscopic myometrial or endometrial resection, but these procedures would be limited to women not wishing to conceive. Laparoscopic myometrial electrocoagulation or excision has proven to be effective but pregnancy following these techniques poses special problems, particularly the increased risk of uterine rupture.

CONCLUSION

Transvaginal ultrasonography can successfully diagnose adenomyosis. Medical and conservative surgical treatments are already available.

Familial risk among patients with endometriosis

PURPOSE

The objective of the present study was to determine the prevalence of endometriosis among the relatives of patients with confirmed endometriosis.

METHODS

We analyzed the prevalence of endometriosis among first-, second-, and third-degree relatives in a group of 101 patients with varying symptoms related to endometriosis seen at two public hospitals and submitted to laparoscopy and/or laparotomy. The control group consisted of 43 women submitted to laparoscopy without a diagnosis of endometriosis.

RESULTS

Among the patients with endometriosis, we detected nine families with a positive history of endometriosis, comprising one mother, six sisters, three aunts, and two cousins, as opposed to no case among the controls.

CONCLUSIONS

These data confirm a familial tendency for endometriosis and suggest that this disorder has a genetic basis.