Impaired fertility in adenomyosis: a murine model reveals endometrial receptivity and progesterone resistance imbalances.

In brief: The impact of adenomyosis on reproductive health needs to be fully understood. By using a murine model, this study provides novel insights into the nuanced mechanisms associated with fertility challenges and offers a foundation for targeted interventions. Abstract: This study investigates the intricate relationship between adenomyosis and reproductive health using a murine model, offering novel insights into this prevalent gynecological disorder. Adenomyosis, characterized by the invasive growth of endometrial tissue into the myometrium, is believed to negatively impact fertility. However, the challenge lies in disentangling this influence, as adenomyosis often coexists with other gynecological diseases. A tamoxifen-induced mice model presents a significant advantage by enabling the specific study of adenomyosis, devoid of confounding influences of concurrent gynecological diseases such as endometriosis. Focusing exclusively on adenomyosis, our study aims to elucidate pathogenic mechanisms underlying fertility issues, focusing on estrous cyclicity, ovarian follicle development, and overall fertility. Our findings uncover disruptions in estrous cyclicity, characterized by an increased duration of time spent in the estrus phase in adenomyosis-induced mice. These disturbances are potentially linked to observed compromised folliculogenesis and the remarkable reduction in litter number and size in mice affected by adenomyosis. Moreover, this study unveils potential drivers of subfertility such as progesterone resistance and altered endometrial receptivity. Within the uteri of mice with adenomyosis, reduced expression of the progesterone receptor and a decreased expression of two implantation-related markers (HoxA10 and integrin ß3) were observed. This comprehensive examination sheds light on the nuanced complexities of adenomyosis-associated reproductive challenges, providing a foundation for targeted interventions in addressing fertility issues related to this disease.

The adenomyosis/endometriosis IVF patient - call for clinical focus.

Endometriosis and adenomyosis are distinct clinical conditions that carry the same pathophysiological features. In recent years the clinical focus on assisted reproductive technology patients with either condition (E/A) has increased, in the recognition that this subgroup of patients might need special attention to obtain reproductive success. Endometriosis and adenomyosis are characterized by a disruption of progesterone and oestrogen signalling pathways, resulting in local oestrogen dominance and progesterone resistance at the receptor level. Recent scientific evidence suggests that the endometrial progesterone receptor resistance encountered in E/A patients can be overcome by a freeze-all policy, followed by down-regulating circulating oestradiol concentrations prior to frozen embryo transfer (FET), in combination with an increase in exogenous luteal phase progesterone supplementation in hormonal replacement therapy (HRT) FET cycles. Specifically, for adenomyosis patients who do not respond to gonadotrophin-releasing hormone agonist down-regulation in terms of a decrease in circulating oestradiol concentrations, a small case series has suggested that the addition of an aromatase inhibitor for 21 days prior to HRT-FET is a valid option. Endometriosis and adenomyosis are hormonally active diseases, which need to be treated by controlling local hyperoestrogenism and progesterone resistance. Based on physiology and recent preliminary clinical data, the authors of this opinion paper wish to stimulate discussion and spark interest in research in E/A patients.

FBXL16 Promotes Endometrial Progesterone Resistance via PP2AB55α /Cyclin D1 Axis in Ishikawa.

Background: F-box proteins are essential components of the E3 ubiquitin ligases which are involved in the regulation of almost all life activities such as cell cycle, proliferation, and apoptosis, which have become an important research and drug target. However, there are few studies on F-box and leucine-rich repeat protein 16 (FBXL16) in endometrial carcinoma. Methods: Clinical samples were collected for determining the correlation between FBXL16 and endometrial carcinoma. Cells were screened and established with Ishikawa cells which proved the fundamental role of FBXL16 in regulating cell proliferation and cell cycle. The MPA-resistant endometrial carcinoma cell line Ishikawa/MPA was established. FBXL16, PP2AB55α , and cyclin D1 were analyzed separately in MPA sensitive and resistant Ishikawa cells in vitro and in vivo. Results: The high expression of FBXL16 was positively correlated with MPA resistance and poor prognosis of endometrial cancer. MPA tolerance of endometrial cancer cells was inhibited by knockdown of FBXL16 in DNA content assessment, CCK-8, and colony formation. It was confirmed that FBXL16 inhibited the activity of substrate PP2AB55α by binding to PP2A, reduced the phosphorylation level at Thr308 site of AKT1, inhibited the expression of GSK-3ß, and thus led to a significant decrease in the phosphorylation level of cyclin D1, which prevented the ubiquitination recognition and degradation of cyclin D1. Conclusion: In our experiments, FBXL16 binds PP2A to promote the dephosphorylation of Thr286 site of cyclin D1 via AKT1/GSK3ß/cyclin D1 pathway, which is required for resisting the ubiquitination degradation and enhances the MPA resistance of Ishikawa.

Loss of MIG-6 results in endometrial progesterone resistance via ERBB2.

Female subfertility is highly associated with endometriosis. Endometrial progesterone resistance is suggested as a crucial element in the development of endometrial diseases. We report that MIG-6 is downregulated in the endometrium of infertile women with endometriosis and in a non-human primate model of endometriosis. We find ERBB2 overexpression in the endometrium of uterine-specific Mig-6 knockout mice (Pgrcre/+Mig-6f/f; Mig-6d/d). To investigate the effect of ERBB2 targeting on endometrial progesterone resistance, fertility, and endometriosis, we introduce Erbb2 ablation in Mig-6d/d mice (Mig-6d/dErbb2d/d mice). The additional knockout of Erbb2 rescues all phenotypes seen in Mig-6d/d mice. Transcriptomic analysis shows that genes differentially expressed in Mig-6d/d mice revert to their normal expression in Mig-6d/dErbb2d/d mice. Together, our results demonstrate that ERBB2 overexpression in endometrium with MIG-6 deficiency causes endometrial progesterone resistance and a nonreceptive endometrium in endometriosis-related infertility, and ERBB2 targeting reverses these effects.

Progesterone Actions and Resistance in Gynecological Disorders.

Estrogen and progesterone and their signaling mechanisms are tightly regulated to maintain a normal menstrual cycle and to support a successful pregnancy. The imbalance of estrogen and progesterone disrupts their complex regulatory mechanisms, leading to estrogen dominance and progesterone resistance. Gynecological diseases are heavily associated with dysregulated steroid hormones and can induce chronic pelvic pain, dysmenorrhea, dyspareunia, heavy bleeding, and infertility, which substantially impact the quality of women's lives. Because the menstrual cycle repeatably occurs during reproductive ages with dynamic changes and remodeling of reproductive-related tissues, these alterations can accumulate and induce chronic and recurrent conditions. This review focuses on faulty progesterone signaling mechanisms and cellular responses to progesterone in endometriosis, adenomyosis, leiomyoma (uterine fibroids), polycystic ovary syndrome (PCOS), and endometrial hyperplasia. We also summarize the association with gene mutations and steroid hormone regulation in disease progression as well as current hormonal therapies and the clinical consequences of progesterone resistance.

Molecular determination of progesterone receptor's PROGINS allele (Alu insertion) and its association with the predisposition and susceptibility to polycystic ovary syndrome (PCOS).

Polycystic ovary syndrome, previously known as Stein-Leventhal syndrome, is associated with altered reproductive endocrinology, predisposing a young woman towards the risk of PCOS. It has a prevalence of 6-20% among the reproductive-age women. Progesterone is a key hormone in the pathophysiology of PCOS and patients show diminished response (progesterone resistance), implicating the role of progesterone receptor (PR) as a factor in the disease etiology and prognosis. In this case-control study, we have used mutation-specific PCR (confirmed by Sanger sequencing) to detect the presence of a pathologically significant PR polymorphic variant called as PROGINS. The variant has an Alu insertion in intron G and has two SNPs in exon 4 and exon 5, with all the three aberrations in complete disequilibrium. Our results demonstrated a statistically significant difference in the frequencies of PROGINS between the PCOS patients and healthy controls (p = 0.047). The frequencies of the genotypes CC (A1/A1), CT (A1/A2), and TT (A2/A2) in patients were 74.50%, 20.58%, and 4.90%, and in healthy controls they were 87.28%, 11%, and 1.69%, respectively. Our results put forward two determining factors with regard to PCOS: (i) the frequency of PROGINS allele was significantly higher among PCOS patients compared to the healthy matched controls (0.15 vs 0.07) in the studied population, (ii) the PROGIN allele was significantly associated with the lower levels of serum progesterone in PCOS patients (p < 0.003). The findings are conspicuous as these relate the PROGINS variant to the increased susceptibility of PCOS and might explain the progesterone resistance in patients.

Role of SIRT1 and Progesterone Resistance in Normal and Abnormal Endometrium.

CONTEXT: Progesterone resistance, a known pathologic condition associated with a reduced cellular response to progesterone and heightened estrogen responses, appears to have a normal physiologic role in mammalian reproduction. The molecular mechanism responsible for progesterone resistance in normal and abnormal endometrium remains unclear. OBJECTIVE: To examine the roles of sirtuin-1 (SIRT1) in normal endometrium as well as endometrium associated with infertility and endometriosis, as an epigenetic modulator associated with progesterone resistance. METHODS: SIRT1 expression was examined by Western blot, quantitative real-time polymerase chain reaction, and immunohistochemistry in mouse uterus and human endometrium. Mice with uterine specific Sirt1 overexpression were developed to examine SIRT1's role in endometrial function and endometriosis development. EX-527, a SIRT1 inhibitor, and SRT1720, a SIRT1 agonist, were also used to evaluate SIRT1 effect on endometriosis. RESULTS: In normal healthy women, endometrial SIRT1 is expressed only during menses. SIRT1 was dramatically overexpressed in the endometrium from women with endometriosis in both the epithelium and stroma. In mice, SIRT1 is expressed at the time of implantation between day 4.5 and 5.5 of pregnancy. Overexpression of SIRT1 in the mouse uterus leads to subfertility due to implantation failure, decidualization defects and progesterone resistance. SIRT1 overexpression in endometriotic lesions promotes worsening endometriosis development. EX-527 significantly reduced the number of endometriotic lesions in the mouse endometriosis model. CONCLUSIONS: SIRT1 expression and progesterone resistance appears to play roles in normal endometrial functions. Aberrant SIRT1 expression contributes to progesterone resistance and may participate in the pathophysiology of endometriosis. SIRT1 is a novel and targetable protein for the diagnosis as well as treatment of endometriosis and the associated infertility seen in this disease.

Peritoneal fluid progesterone and progesterone resistance in superficial endometriosis lesions.

Peritoneal fluid in ovulatory women is an ovarian exudate with higher estrogen and progesterone concentrations than in plasma. In the follicular phase, progesterone concentrations are as high as plasma concentrations in the luteal phase. After ovulation, estrogen and progesterone concentrations in the peritoneal fluid are 5-10 times higher than in plasma, both in women with and without endometriosis. The histologically proliferative aspect without secretory changes of most superficial subtle lesions is not compatible with the progesterone concentrations in the peritoneal fluid. Therefore, we have to postulate a strong progesterone resistance in these lesions. The mechanism is unclear and might be a peritoneal fluid effect in women with predisposing defects in the endometrium, or isolated endometrial glands with progesterone resistance, or subtle lesions originating from the basal endometrium: the latter hypothesis is attractive since in basal endometrium progesterone does not induce secretory changes while progesterone withdrawal, not occurring in peritoneal fluid, is required to resume mitotic activity and proliferation. Hormone concentrations in the peritoneal fluid are an important factor in understanding the medical therapy of endometriosis. The effect of oestro-progestin therapy on superficial endometriosis lesions seems to be a consequence of the decreased estrogen concentrations rather than a direct progestin effect. In conclusion, the peritoneal fluid, being a secretion product of the ovarian follicule, deserves more attention in the pathophysiology and treatment of endometriosis.

Fatostatin reverses progesterone resistance by inhibiting the SREBP1-NF-κB pathway in endometrial carcinoma.

Progesterone resistance can significantly restrict the efficacy of conservative treatment for patients with endometrial cancer who wish to preserve their fertility or those who suffer from advanced and recurrent cancer. SREBP1 is known to be involved in the occurrence and progression of endometrial cancer, although the precise mechanism involved remains unclear. In the present study, we carried out microarray analysis in progesterone-sensitive and progesterone-resistant cell lines and demonstrated that SREBP1 is related to progesterone resistance. Furthermore, we verified that SREBP1 is over-expressed in both drug-resistant tissues and cells. Functional studies further demonstrated that the inhibition of SREBP1 restored the sensitivity of endometrial cancer to progesterone both in vitro and in vivo, and that the over-expression of SREBP1 promoted resistance to progesterone. With regards to the mechanism involved, we found that SREBP1 promoted the proliferation of endometrial cancer cells and inhibited their apoptosis by activating the NF-κB pathway. To solve the problem of clinical application, we found that Fatostatin, an inhibitor of SREBP1, could increase the sensitivity of endometrial cancer to progesterone and reverse progesterone resistance by inhibiting SREBP1 both in vitro and in vivo. Our results highlight the important role of SREBP1 in progesterone resistance and suggest that the use of Fatostatin to target SREBP1 may represent a new method to solve progesterone resistance in patients with endometrial cancer.

Therapeutic Potentials of Low-Dose Tacrolimus for Aberrant Endometrial Features in Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) is a major anovulatory infertility affecting a great proportion of women of childbearing age and is associated with obesity, insulin resistance and chronic inflammation. Poor endometrial receptivity and recurrent implantation failure are major hurdles to the establishment of pregnancy in women with PCOS. The accumulating body of evidence obtained from experimental and clinical studies suggests a link between inherent adaptive and innate immune irregularities and aberrant endometrial features in PCOS. The use of conventional therapeutic interventions such as lifestyle modification, metformin and ovarian stimulation has achieved limited clinical success in restoring ovulation and endometrial receptivity in women with PCOS. Unlike other immunosuppressive drugs prescribed in the clinical management of autoimmune and inflammatory disorders that may have deleterious effects on fertility and fetal development, preclinical studies in mice and in women without PCOS but with repeated implantation failure revealed potential therapeutic benefits for the use of low-dose tacrolimus in treating female infertility. Improved systemic and ovarian immune functions, endometrial progesterone receptor and coreceptor expressions and uterine vascular adaptation to pregnancy were among features of enhanced progesterone-receptor sensitivity in the low-dose tacrolimus-treated mouse model of the disease. In this review, we have compiled available experimental and clinical data in literature on endometrial progesterone resistance and current therapeutic options, as well as mechanisms of actions and reported outcomes relevant to the potential therapeutic benefits for the use of low-dose tacrolimus in treating PCOS-associated female infertility.

Functional similarity between TGF-beta type 2 and type 1 receptors in the female reproductive tract.

Transforming growth factor ß (TGFß) signaling plays critical roles in reproductive development and function. TGFß ligands signal through the TGFß receptor type 2 (TGFBR2)/TGFBR1 complex. As TGFBR2 and TGFBR1 form a signaling complex upon ligand stimulation, they are expected to be equally important for propagating TGFß signaling that elicits cellular responses. However, several genetic studies challenge this concept and indicate that disruption of TGFBR2 or TGFBR1 may lead to contrasting phenotypic outcomes. We have shown that conditional deletion of Tgfbr1 using anti-Mullerian hormone receptor type 2 (Amhr2)-Cre causes oviductal and myometrial defects. To determine the functional requirement of TGFBR2 in the female reproductive tract and the potential phenotypic divergence/similarity resulting from conditional ablation of either receptor, we generated mice harboring Tgfbr2 deletion using the same Cre driver that was previously employed to target Tgfbr1. Herein, we found that conditional deletion of Tgfbr2 led to a similar phenotype to that of Tgfbr1 deletion in the female reproductive tract. Furthermore, genetic removal of Tgfbr1 in the Tgfbr2-deleted uterus had minimal impact on the phenotype of Tgfbr2 conditional knockout mice. In summary, our results reveal the functional similarity between TGFBR2 and TGFBR1 in maintaining the structural integrity of the female reproductive tract.

CNR1 may reverse progesterone-resistance of endometrial cancer through the ERK pathway.

Endocrine therapy is a promising treatment for endometrial cancer (EC) that preserves fertility, however, progesterone-resistance is currently the major challenges. The Cancer Genome Atlas (TCGA) database analysis showed that CNR1 was closely have a negative correlation with overall survival (OS) and relapse-free survival (RFS) in endometrial cancer. To explore the role of CNR1 in progesterone resistance and possible molecular regulation mechanism, we established stable progesterone-resistant cell lines (IshikawaPR) via progesterone tolerance of ordinary cancer cells (Ishikawa). The difference of CNR1 level in two cell lines was assessed by MTT, RT-PCR, Western blot, immunofluorescence. Then, lentiviruses constructed CNR1-knockdown with GV248 as the tool vector were used to transfect IshikwaPR cells, and the changes of biological behavior and progesterone sensitivity was verified respectively through plate cloning experiment, EdU assay, flow cytometry cycle analysis, transwell, Scratch test, etc. We founded after CNR1 was knocked down, the proliferative activity and ability to migrate of IshikawaPR cells decreased, progesterone-response sensitivity could be improved. Moreover, knockdown of CNR1 can also down-regulate ERK and NFκ B expression and activation. Furthermore, subcutaneous xenograft in nude mice was tested similarly in vivo. The above datas suggest that targeting CNR1 may reverse the progesterone resistance in endometrial cancer and may coordinate the role of ERK pathway activation.

Genital abnormalities associated to lack of uterine adenogenesis or endometrial gland dysgenesis of female dromedary camels (Camelus dromedarius).

Background: The developmental disruption of the müllerian duct and the endometrial dynamic can generate genital lesions that could contribute to infertility. Aim: This paper discusses two cases of genital conditions associated to endometrial gland pathologies in nulliparous female camels. Methods: Macroscopic examinations and histopathological description were performed on congenital and acquired genital abnormalities with endometrial gland anomalies. Results: The first case is endometrial gland agenesis associated to unilateral uterine aplasia, and the second case is endometrial gland dysgenesis associated to metritis. The prevalence of each case is estimated to be 0.6%. The most specific microscopic features associated to the endometrial gland agenesis were the presence of endometrial stromal proliferation and homogenous hyalinization of the myometrium. The acute metritis was associated to endometrial-activated stroma with focal infiltration with inflammatory cells on the endometrium and myometrium and the spontaneous endometrial gland dysgenesis. Conclusion: This study reveals the importance of congenital abnormalities during the routine reproductive examination of peripubertal animals, as well as the association of histopathological complementary examination for the research functional and inflammatory anomalies of the uterus. Genetic screening of breeders would be very important in the search for genetic risk factors associated with these congenital pathologies, which can be disseminated by reproductive biotechnologies.

Progesterone receptor ligands for the treatment of endometriosis: the mechanisms behind therapeutic success and failure.

BACKGROUND: Despite intense research, it remains intriguing why hormonal therapies in general and progestins in particular sometimes fail in endometriosis. OBJECTIVE AND RATIONALE: We review here the action mechanisms of progesterone receptor ligands in endometriosis, identify critical differences between the effects of progestins on normal endometrium and endometriosis and envisage pathways to escape drug resistance and improve the therapeutic response of endometriotic lesions to such treatments. SEARCH METHODS: We performed a systematic Pubmed search covering articles published since 1958 about the use of progestins, estro-progestins and selective progesterone receptor modulators, to treat endometriosis and its related symptoms. Two reviewers screened the titles and abstracts to select articles for full-text assessment. OUTCOMES: Progesterone receptor signalling leads to down-regulation of estrogen receptors and restrains local estradiol production through interference with aromatase and 17 beta-hydroxysteroid dehydrogenase type 1. Progestins inhibit cell proliferation, inflammation, neovascularisation and neurogenesis in endometriosis. However, progesterone receptor expression is reduced and disrupted in endometriotic lesions, with predominance of the less active isoform (PRA) over the full-length, active isoform (PRB), due to epigenetic abnormalities affecting the PGR gene transcription. Oxidative stress is another mechanism involved in progesterone resistance in endometriosis. Among the molecular targets of progesterone in the normal endometrium that resist progestin action in endometriotic cells are the nuclear transcription factor FOXO1, matrix metalloproteinases, the transmembrane gap junction protein connexin 43 and paracrine regulators of estradiol metabolism. Compared to other phenotypes, deep endometriosis appears to be more resistant to size regression upon medical treatments. Individual genetic characteristics can affect the bioavailability and pharmacodynamics of hormonal drugs used to treat endometriosis and, hence, explain part of the variability in the therapeutic response. WIDER IMPLICATIONS: Medical treatment of endometriosis needs urgent innovation, which should start by deeper understanding of the disease core features and diverse phenotypes and idiosyncrasies, while moving from pure hormonal treatments to drug combinations or novel molecules capable of restoring the various homeostatic mechanisms disrupted by endometriotic lesions.

CRISPR/Cas9-Mediated Gene Knockout of ARID1A Promotes Primary Progesterone Resistance by Downregulating Progesterone Receptor B in Endometrial Cancer Cells.

Medroxyprogesterone (MPA) is used for the conservative treatment of endometrial cancer. Unfortunately, progesterone resistance seriously affects its therapeutic effect. The purpose of the current study was to investigate the influence of deletion of AT-rich interactive domain 1A (ARID1A) in progesterone resistance in Ishikawa cells. Ablation of ARID1A was conducted through the CRISPR/Cas9 technology. Acquired progesterone-resistant Ishikawa (Ishikawa-PR) cells were generated by chronic exposure of Ishikawa cells to MPA. The sensitivity of the parental Ishikawa, Ishikawa-PR, and ARID1A-deficient cells to MPA and/or LY294002 was determined using the Cell Counting Kit-8 (CCK-8) assay and flow cytometry analysis. In addition, Western blot analysis and reverse transcription-polymerase chain reaction was performed to evaluate the mRNA and protein expression levels of ARID1A, progesterone receptor B (PRB), and P-AKT. Both Ishikawa-PR and ARID1A knockout cells showed insensitivity to MPA, downregulation of PRB, and hyperphosphorylation of AKT compared to the parental Ishikawa cells. Pretreatment with LY294002 significantly enhanced the ability of MPA to suppress proliferation and to induce apoptosis in the parental and Ishikawa-PR cells via the inhibition of AKT activation and upregulation of PRB transcriptional activity. However, the PRB transcriptional activity and insensitivity to MPA were irreversible by LY294002 in ARID1A-deficient cells. Ablation of ARID1A is associated with low PRB expression, which serves an important role in primary progesterone resistance. Akt inhibition cannot rescue PRB or sensitize to MPA in ARID1A knockout cells. These findings suggest that ARID1A may act as a reliable biomarker to predict the response for the combination of AKT inhibitor and MPA treatment.

The ultrastructural effects of surgical treatment of hydrosalpinx on the human endometrium: a light and electron microscopic study.

Hydrosalpinx is a disease commonly observed in women and characterized by the obstruction which is in the shape of a fluid-filled sac at the distal part of tuba uterina closed to the ovary. In this study, we aimed to obtain endometrial tissue samples from the hydrosalpinx patients, before and after the surgical treatment and compare these endometrial tissue samples by using light and electron microscope. Endometrial tissue samples were obtained from the 24 women with bilateral hydrosalpinx range 19-46 years before and after the surgical treatment, and normal endometrial tissues were collected from five women without hydrosalpinx and evaluated as a control group. In endometrial samples of hydrosalpinx patients; it was observed that large and unregulated interstitial spaces representing the organellar destruction, membranous whorl structures associated with organelle destruction, thinning in the surface epithelium, decreasing in numbers of microvillus and pinopodes in microvilli cells, increasing in heterochromatin and picnotic changes in the nucleus, expansion, and vacuolization in the endoplasmic reticulum cisternae in the apical cytoplasm and intraepithelial macrophages and lymphocytes were rised in number. Although mild structural changes were observed in endometrial tissues obtained after surgical treatment of hydrosalpinx, surface epithelium, glandular and stromal cell structures were more similar to control endometrial specimens. In conclusion; serious structural changes have occurred in endometrial tissues of hydrosalpinx patients. These structural abnormalities have removed after surgical treatment so it is considered that surgical treatment is effective in patients with hydrosalpinx.

Endometriosis.

Pelvic endometriosis is a complex syndrome characterized by an estrogen-dependent chronic inflammatory process that affects primarily pelvic tissues, including the ovaries. It is caused when shed endometrial tissue travels retrograde into the lower abdominal cavity. Endometriosis is the most common cause of chronic pelvic pain in women and is associated with infertility. The underlying pathologic mechanisms in the intracavitary endometrium and extrauterine endometriotic tissue involve defectively programmed endometrial mesenchymal progenitor/stem cells. Although endometriotic stromal cells, which compose the bulk of endometriotic lesions, do not carry somatic mutations, they demonstrate specific epigenetic abnormalities that alter expression of key transcription factors. For example, GATA-binding factor-6 overexpression transforms an endometrial stromal cell to an endometriotic phenotype, and steroidogenic factor-1 overexpression causes excessive production of estrogen, which drives inflammation via pathologically high levels of estrogen receptor-ß. Progesterone receptor deficiency causes progesterone resistance. Populations of endometrial and endometriotic epithelial cells also harbor multiple cancer driver mutations, such as KRAS, which may be associated with the establishment of pelvic endometriosis or ovarian cancer. It is not known how interactions between epigenomically defective stromal cells and the mutated genes in epithelial cells contribute to the pathogenesis of endometriosis. Endometriosis-associated pelvic pain is managed by suppression of ovulatory menses and estrogen production, cyclooxygenase inhibitors, and surgical removal of pelvic lesions, and in vitro fertilization is frequently used to overcome infertility. Although novel targeted treatments are becoming available, as endometriosis pathophysiology is better understood, preventive approaches such as long-term ovulation suppression may play a critical role in the future.

Comprehensive bioinformatics analysis of acquired progesterone resistance in endometrial cancer cell line.

BACKGROUND: Progesterone resistance is a problem in endometrial carcinoma, and its underlying molecular mechanisms remain poorly understood. The aim of this study was to elucidate the molecular mechanisms of progesterone resistance and to identify the key genes and pathways mediating progesterone resistance in endometrial cancer using bioinformatics analysis. METHODS: We developed a stable MPA (medroxyprogesterone acetate)-resistant endometrial cancer cell subline named IshikawaPR. Microarray analysis was used to identify differentially expressed genes (DEGs) from triplicate samples of Ishikawa and IshikawaPR cells. PANTHER, DAVID and Metascape were used to perform gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and cBioPortal for progesterone receptor (PGR) coexpression analysis. GEO microarray (GSE17025) was utilized for validation. The protein-protein interaction network (PPI) and modular analyses were performed using Metascape and Cytoscape. Further validation were performed by real-time polymerase chain reaction (RT-PCR). RESULTS: In total, 821 DEGs were found and further analyzed by GO, KEGG pathway enrichment and PPI analyses. We found that lipid metabolism, immune system and inflammation, extracellular environment-related processes and pathways accounted for a significant portion of the enriched terms. PGR coexpression analysis revealed 7 PGR coexpressed genes (ANO1, SOX17, CGNL1, DACH1, RUNDC3B, SH3YL1 and CRISPLD1) that were also dramatically changed in IshikawaPR cells. Kaplan-Meier survival statistics revealed clinical significance for 4 out of 7 target genes. Furthermore, 8 hub genes and 4 molecular complex detections (MCODEs) were identified. CONCLUSIONS: Using microarray and bioinformatics analyses, we identified DEGs and determined a comprehensive gene network of progesterone resistance. We offered several possible mechanisms of progesterone resistance and identified therapeutic and prognostic targets of progesterone resistance in endometrial cancer.