Anti-Müllerian hormone inhibits growth of AMH type II receptor-positive human ovarian granulosa cell tumor cells by activating apoptosis

Activin receptors in human cancer: Functions, mechanisms, and potential clinical applications

Activins are members of the transforming growth factor-β (TGF-β) superfamily and act as key regulators in various physiological processes, such as follicle and embryonic development, as well as in multiple human diseases, including cancer. They have been established to signal through three type I and two type II serine/threonine kinase receptors, which, upon ligand binding, form a final signal-transducing receptor complex that activates downstream signaling and governs gene expression. Recent research highlighted the dysregulation of the expression or activity of activin receptors in multiple human cancers and their critical involvement in cancer progression. Furthermore, expression levels of activin receptors have been associated with clinicopathological features and patient outcomes across different cancers. However, there is currently a paucity of comprehensive systematic reviews of activin receptors in cancer. Thus, this review aimed to consolidate existing knowledge concerning activin receptors, with a primary emphasis on their signaling cascade and emerging biological functions, regulatory mechanisms, and potential clinical applications in human cancers in order to provide novel perspectives on cancer prognosis and targeted therapy.

Impact of In Ovo Leptin Injection and Dietary Protein Levels on Ovarian Growth Markers and Early Folliculogenesis in Post-Hatch Chicks (Gallus gallus domesticus)

Genetically bred for rapid growth, broiler breeder hens develop obesity and ovarian dysfunction when fed ad libitum, resembling a condition that resembles human polycystic ovary syndrome (PCOS). Nutritional control applies to post-hatched chicks from one week onward to prevent the development of a PCOS-like phenotype in adult broilers. This study investigated the impact of a growth marker, leptin, and post-hatch nutritional intake on early-life ovarian function. Fertile broiler eggs were injected in ovo with physiological saline solution or 5 µg of leptin and then incubated. After hatching, female chicks were fed ad libitum a diet containing low protein (17% low crude protein (LP)) or standard protein (22% standard crude protein (SP)). Tissues were collected from 7- and 28-day-old chicks for RT-qPCR and histological analysis. In contrast to the LP diet, the SP diet suppressed the mRNA expression of ovarian growth markers essential for folliculogenesis in post-hatched chicks. Leptin injection did not influence ovarian growth markers but increased pituitary gonadotropin transcripts in 7-day-old chicks fed with LP diet. No treatment effects on follicle activation were noted on day 7, but by day 28, in ovo leptin-treated LP-fed chicks exhibited a higher percentage of primary follicles. These changes may have resulted from the early upregulation of genes by leptin during the first week, including pituitary gonadotropins and ovarian leptin receptors. The decline in ovarian growth markers with the SP diet highlights the importance of precise post-hatch protein calculation, which may influence future ovarian function in animals. These findings may contribute to future dietary strategies to enhance broiler reproduction.

SMAD signaling pathway is disrupted by BPA via the AMH receptor in bovine granulosa cells†

Significant events that determine oocyte competence occur during follicular growth and oocyte maturation. The anti-Mullerian hormone, a positive predictor of fertility, has been shown to be affected by exposure to endocrine disrupting compounds, such as bisphenol A and S. However, the interaction between bisphenols and SMAD proteins, mediators of the anti-Mullerian hormone pathway, has not yet been elucidated. AMH receptor (AMHRII) and downstream SMAD expression was investigated in bovine granulosa cells treated with bisphenol A, bisphenol S, and then competitively with the anti-Mullerian hormone. Here, we show that 24-h bisphenol A exposure in granulosa cells significantly increased SMAD1, SMAD4, and SMAD5 mRNA expression. No significant changes were observed in AMHRII or SMADs protein expression after 24-h treatment. Following 12-h treatments with bisphenol A (alone or with the anti-Mullerian hormone), a significant increase in SMAD1 and SMAD4 mRNA expression was observed, while a significant decrease in SMAD1 and phosphorylated SMAD1 was detected at the protein level. To establish a functional link between bisphenols and the anti-Mullerian hormone signaling pathway, antisense oligonucleotides were utilized to suppress AMHRII expression with or without bisphenol exposure. Initially, transfection conditions were optimized and validated with a 70% knockdown achieved. Our findings show that bisphenol S exerts its effects independently of the anti-Mullerian hormone receptor, while bisphenol A may act directly through the anti-Mullerian hormone signaling pathway providing a potential mechanism by which bisphenols may exert their actions to disrupt follicular development and decrease oocyte competence.

Cancer-associated mesothelial cells are regulated by the anti-Müllerian hormone axis

Cancer-associated mesothelial cells (CAMCs) in the tumor microenvironment are thought to promote growth and immune evasion. We find that, in mouse and human ovarian tumors, cancer cells express anti-Müllerian hormone (AMH) while CAMCs express its receptor AMHR2, suggesting a paracrine axis. Factors secreted by cancer cells induce AMHR2 expression during their reprogramming into CAMCs in mouse and human in vitro models. Overexpression of AMHR2 in the Met5a mesothelial cell line is sufficient to induce expression of immunosuppressive cytokines and growth factors that stimulate ovarian cancer cell growth in an AMH-dependent way. Finally, syngeneic cancer cells implanted in transgenic mice with Amhr2-/- CAMCs grow significantly slower than in wild-type hosts. The cytokine profile of Amhr2-/- tumor-bearing mice is altered and their tumors express less immune checkpoint markers programmed-cell-death 1 (PD1) and cytotoxic T lymphocyte-associated protein 4 (CTLA4). Taken together, these data suggest that the AMH/AMHR2 axis plays a critical role in regulating the pro-tumoral function of CAMCs in ovarian cancer.

Evaluation of the p53 pathway in polycystic ovarian syndrome pathogenesis and apoptosis enhancement in human granulosa cells through transcriptome data analysis

The polycystic ovarian syndrome (PCOS) is closely associated with enhanced apoptosis of granulosa cells, which have a vital role in maturation of oocytes. p53 plays a critical role in the regulation of apoptosis and cell cycle arrest, metabolism and insulin resistance. The aim of this study was to investigate the impact of p53 pathway in enhancing apoptosis and abnormal function of granulosa cells. In this study, microarray analysis and RNA sequencing were downloaded from the GEO and used as datasets. Principal Component Analysis (PCA) and online SSizer tool were applied to evaluate the experiment quality control and sample sufficiency, respectively. Bioinformatics' analyses were performed on the selected datasets, and validated by qRT-PCR and western blot analyses. Three datasets out of five ones were chosen for re-analyzing based on the PCA outcomes. 21 deregulated genes were identified via filters including p < 0.05 and |log2FC|≥ 1. Functional enrichment analysis confirmed the relevance of cell cycle regulation and apoptosis as common biological hallmarks in PCOS. Results have shown differentially expressed p53 target genes involved in apoptosis (BAX, FAS, PMAIP1, and CASP8), cell cycle (Cyclins, Cyclin dependent kinases), glucose metabolism and insulin resistance (THBS1), and p53 regulation (MDM2). Subsequently, the relative mRNA expression of FAS, PMAIP1 and MDM2 genes, and protein levels of p53 and MDM2 were confirmed using granulosa cells collected from 20 PCOS women and 18 control individuals by qRT-PCR and western blot, respectively. Results of this study represent the possible role of p53 pathway in pathogenesis of PCOS particularly, through the enhancement of apoptosis in granulosa cells.

Multi-omics therapeutic perspective on ACVR1 gene: from genetic alterations to potential targeting

Activin A receptor type I (ACVR1), a transmembrane serine/threonine kinase, belongs to the transforming growth factor-β superfamily, which signals via phosphorylating the downstream effectors and SMAD transcription factors. Its central role in several biological processes and intracellular signaling is well known. Genetic variation in ACVR1 has been associated with a rare disease, fibrodysplasia ossificans progressive, and its somatic alteration is reported in rare cancer diffuse intrinsic pontine glioma. Furthermore, altered expression or variation of ACVR1 is associated with multiple pathologies such as polycystic ovary syndrome, congenital heart defects, diffuse idiopathic skeletal hyperostosis, posterior fossa ependymoma and other malignancies. Recent advancements have witnessed ACVR1 as a potential pharmacological target, and divergent promising approaches for its therapeutic targeting have been explored. This review highlights the structural and functional characteristics of receptor ACVR1, associated signaling pathways, genetic variants in several diseases and cancers, protein-protein interaction, gene expression, regulatory miRNA prediction and potential therapeutic targeting approaches. The comprehensive knowledge will offer new horizons and insights into future strategies harnessing its therapeutic potential.

Bone Morphogenetic Protein Signaling in Cancer; Some Topics in the Recent 10 Years

Bone morphogenetic proteins (BMPs), members of the transforming growth factor-β (TGF-β) family, are multifunctional cytokines. BMPs have a broad range of functions, and abnormalities in BMP signaling pathways are involved in cancer progression. BMPs activate the proliferation of certain cancer cells. Malignant phenotypes of cancer cells, such as increased motility, invasiveness, and stemness, are enhanced by BMPs. Simultaneously, BMPs act on various cellular components and regulate angiogenesis in the tumor microenvironment. Thus, BMPs function as pro-tumorigenic factors in various types of cancer. However, similar to TGF-β, which shows both positive and negative effects on tumorigenesis, BMPs also act as tumor suppressors in other types of cancers. In this article, we review important findings published in the recent decade and summarize the pro-oncogenic functions of BMPs and their underlying mechanisms. The current status of BMP-targeted therapies for cancers is also discussed.

Estradiol promotes cell survival and induces Greb1 expression in granulosa cell tumors of the ovary through an ERα-dependent mechanism

Granulosa cell tumor (GCT) is a form of ovarian tumor characterized by its tendency to recur years after surgical ablation. Little is known on the mechanisms involved in GCT development and progression. GCTs can produce estradiol (E2), but whether this hormone could play a role in this cancer through its nuclear receptors, i.e., ERα and ERβ, remains unknown. Here, we addressed this issue by cell-based and molecular studies on human GCTs and GCT cell lines. Importantly, we observed that E2 significantly increased the growth of GCT cells by promoting cell survival. The use of selective agonists of each type of receptor, together with Esr1 (ERα) or Esr2 (ERβ)-deleted GCT cells revealed that E2 mediated its effects through ERα-dependent genomic mechanisms and ERβ/ERα-dependent extra-nuclear mechanisms. Notably, the expression of Greb1, a prototypical ER target gene, was dose-dependently up-regulated by E2 specifically through ERα in GCT cells. Accordingly, using GCTs from patients, we found that GREB1 mRNA abundance was positively correlated to intra-tumoral E2 concentrations. Tissue microarrays analyses showed that there were various combinations of ER expression in primary and recurrent GCTs, and that ERα expression persisted only in combination with ERβ in ~40% of recurrent tumors. Altogether, this study demonstrates that E2 can promote the progression of GCTs, with a clear dependence on ERα. In addition to demonstrating that GCTs can be classified as a hormone-related cancer, our results also highlight that the nature of ER forms present in recurrent GCTs could underlie the variable efficiency of endocrine therapies. This article is protected by copyright. All rights reserved.

Anti-Müllerian Hormone in Female Reproduction

Anti-Müllerian hormone (AMH), also called Müllerian inhibiting substance, was shown to be synthesized by the ovary in the 1980s. This article reviews the main findings of the past 20 years on the regulation of the expression of AMH and its specific receptor AMHR2 by granulosa cells, the mechanism of action of AMH, the different roles it plays in the reproductive organs, its clinical utility, and its involvement in the principal pathological conditions affecting women. The findings in respect of regulation tell us that AMH and AMHR2 expression is mainly regulated by bone morphogenetic proteins, gonadotropins, and estrogens. It has now been established that AMH regulates the different steps of folliculogenesis and that it has neuroendocrine effects. On the other hand, the importance of serum AMH as a reliable marker of ovarian reserve and as a useful tool in the prediction of the polycystic ovary syndrome (PCOS) and primary ovarian failure has also been acknowledged. Last but not least, a large body of evidence points to the involvement of AMH in the pathogenesis of PCOS.

Translational Physiology of Anti-Müllerian Hormone: Clinical Applications in Female Fertility Preservation and Cancer Treatment

Background

Whilst the ability of AMH to induce the regression of the Müllerian ducts in the male fetus is well appreciated, AMH has additional biological actions in relation to steroid biosynthesis and ovarian follicle dynamics. An understanding of the physiology of AMH illuminates the potential therapeutic utility of AMH to protect the ovarian reserve during chemotherapy and in the treatment of female malignancies. The translation of the biological actions of AMH into clinical applications is an emerging focus of research, with promising preliminary results.

Objective and Rationale

Studies indicate AMH restrains primordial follicle development, thus administration of AMH during chemotherapy may protect the ovarian reserve by preventing the mass activation of primordial follicles. As AMH induces regression of tissues expressing the AMH receptor (AMHRII), administration of AMH may inhibit growth of malignancies expressing AMHR II. This review evaluates the biological actions of AMH in females and appraises human clinical applications.

Search Methods

A comprehensive search of the Medline and EMBASE databases seeking articles related to the physiological functions and therapeutic applications of AMH was conducted in July 2021. The search was limited to studies published in English.

Outcomes

AMH regulates primordial follicle recruitment and moderates sex steroid production through the inhibition of transcription of enzymes in the steroid biosynthetic pathway, primarily aromatase and 17α-hydroxylase/17,20-lyase. Preliminary data indicates that administration of AMH to mice during chemotherapy conveys a degree of protection to the ovarian reserve. Administration of AMH at the time of ovarian tissue grafting has the potential to restrain uncontrolled primordial follicle growth during revascularization. Numerous studies demonstrate AMH induced regression of AMHR II expressing malignancies. As this action occurs via a different mechanism to traditional chemotherapeutic agents, AMH has the capacity to inhibit proliferation of chemo-resistant ovarian cancer cells and cancer stem cells.

Wider Implications

To date, AMH has not been administered to humans. Data identified in this review suggests administration of AMH would be safe and well tolerated. Administration of AMH during chemotherapy may provide a synchronistic benefit to women with an AMHR II expressing malignancy, protecting the ovarian reserve whilst the cancer is treated by dual mechanisms.

BPA and BPS affect the expression of anti-Mullerian hormone (AMH) and its receptor during bovine oocyte maturation and early embryo development

BACKGROUND

Exposure to endocrine-disrupting chemicals, such as Bisphenol A (BPA) and Bisphenol S (BPS), is widespread and has negative implications on embryonic development. Preliminary evidence revealed that in women undergoing IVF treatment, urinary BPA levels were associated with low serum anti-Mullerian hormone, however a definitive relationship between the two has not yet been characterized.

METHODS

This study aimed to evaluate BPA and BPS effects on in vitro oocyte maturation and early preimplantation embryo development through i) analysis of anti-Mullerian hormone (AMH) and anti-Mullerian hormone receptor II (AMHRII), ii) investigation of developmental parameters, such as cleavage, blastocyst rates and developmental arrest, iii) detection of apoptosis and iv) assessment of possible sex ratio skew. An in vitro bovine model was used as a translational model for human early embryonic development. We first assessed AMH and AMHRII levels after bisphenol exposure during oocyte maturation. Zygotes were also analyzed during cleavage and blastocysts stages. Techniques used include in vitro fertilization, quantitative polymerase chain reaction (qPCR), western blotting, TUNEL and immunofluorescence.

RESULTS

Our findings show that BPA significantly decreased cleavage (p < 0.001), blastocyst (p < 0.005) and overall developmental rates as well as significantly increased embryonic arrest at the 2-4 cell stage (p < 0.05). Additionally, both BPA and BPS significantly increased DNA fragmentation in 2-4 cells, 8-16 cells and blastocyst embryos (p < 0.05). Furthermore, BPA and BPS alter AMH and AMHRII at the mRNA and protein level in both oocytes and blastocysts. BPA, but not BPS, also significantly skews sex ratios towards female blastocysts (p < 0.05).

CONCLUSION

This study shows that BPA affects AMH and AMHRII expression during oocyte maturation and that BPS exerts its effects to a greater extent after fertilization and therefore may not be a safer alternative to BPA. Our data lay the foundation for future functional studies, such as receptor kinetics, downstream effectors, and promoter activation/inhibition to prove a functional relationship between bisphenols and the AMH signalling system.

Anti-Müllerian hormone concentration regulates activin receptor-like kinase-2/3 expression levels with opposing effects on ovarian cancer cell survival

Anti‑Müllerian hormone (AMH) type II receptor (AMHRII) and the AMH/AMHRII signaling pathway are potential therapeutic targets in ovarian carcinoma. Conversely, the role of the three AMH type I receptors (AMHRIs), namely activin receptor‑like kinase (ALK)2, ALK3 and ALK6, in ovarian cancer remains to be clarified. To determine the respective roles of these three AMHRIs, the present study used four ovarian cancer cell lines (COV434‑AMHRII, SKOV3‑AMHRII, OVCAR8, KGN) and primary cells isolated from tumor ascites from patients with ovarian cancer. The results demonstrated that ALK2 and ALK3 may be the two main AMHRIs involved in AMH signaling at physiological endogenous and supraphysiological exogenous AMH concentrations, respectively. Supraphysiological AMH concentrations (25 nM recombinant AMH) were associated with apoptosis in all four cell lines and decreased clonogenic survival in COV434‑AMHRII and SKOV3‑AMHRII cells. These biological effects were induced via ALK3 recruitment by AMHRII, as ALK3‑AMHRII dimerization was favored at increasing AMH concentrations. By contrast, ALK2 was associated with AMHRII at physiological endogenous concentrations of AMH (10 pM). Based on these results, tetravalent IgG1‑like bispecific antibodies (BsAbs) against AMHRII and ALK2, and against AMHRII and ALK3 were designed and evaluated. In vivo, COV434‑AMHRII tumor cell xenograft growth was significantly reduced in all BsAb‑treated groups compared with that in the vehicle group (P=0.018 for BsAb 12G4‑3D7; P=0.001 for all other BsAbs). However, the growth of COV434‑AMHRII tumor cell xenografts was slower in mice treated with the anti‑AMRII‑ALK2 BsAb 12G4‑2F9 compared with that in animals that received a control BsAb that targeted AMHRII and CD5 (P=0.048). These results provide new insights into type I receptor specificity in AMH signaling pathways and may lead to an innovative therapeutic approach to modulate AMH signaling using anti‑AMHRII/anti‑AMHRI BsAbs.

Case report: The case of a 17 kg ovarian granulosa cell tumor in a Breton draft mare

Granulosa cell tumor (GCT) is a benign tumor which affects the mare's ovaries. In this report, a case of unilateral GCT in an ovary, which weighed 17.04 kg, of a 9-year-old Breton draft mare is described. A transrectal ultrasonography exam revealed a unilateral multi-cystic enlarged ovary. Laparoscopic ovariectomy was difficult due to enlargement of blood vessels in the ovarian broad ligament. The mare was necropsied, and the pathological changes in the GCT-affected ovary and unaffected ovary were evaluated. The ovarian mass in the GCT-affected ovary had a cribriform pattern and was positive for anti-Müllerian hormone (AMH) and its receptor (AMHR2). The contralateral ovary showed no follicular development and was negative for AMH. AMHR2 was positively expressed in stromal cells. The AMH concentration in plasma was 4,210 ng/ml. This is the first report showing the presence of AMH (2,210 ng/ml) in ascites fluid, and it also shows that laparoscopic ovariectomy might not be suitable for larger ovaries affected by a GCT. Ultrasonographic, endocrine, and histopathological analyses were helpful for making a definitive diagnosis of GCT in this mare.

Murlentamab, a Low Fucosylated Anti-Müllerian Hormone Type II Receptor (AMHRII) Antibody, Exhibits Anti-Tumor Activity through Tumor-Associated Macrophage Reprogrammation and T Cell Activation

Simple Summary

AMHRII, the anti-Müllerian hormone receptor, is selectively expressed in normal sexual organs in healthy adults but is also re-expressed in ovarian, colorectal and lung cancers. In this context, we developed murlentamab, a humanized glyco-engineered anti-AMHRII monoclonal antibody, currently in clinical trial. Preliminary data suggest that murlentamab anti-tumor activity involves immune response activation. Thus, in vitro experiments were performed to precisely characterize the murlentamab effect on the human immune system. We show that murlentamab treatment is associated with evidences of innate and adaptive immune cell activation in cancer patient samples. Moreover, we demonstrate that the murlentamab opsonization of AMHRII-expressing ovarian tumor cells promotes a polarization switch of both naïve and tumor-associated macrophages towards an anti-tumor M1-like phenotype. Our work also supports that, through macrophage reeducation, murlentamab activates an anti-tumor adaptive immune response. Finally, the combination of murlentamab with pembrolizumab confirmed novel clinical perspectives of murlentamab association with checkpoint inhibitors and other immuno-modulators.

Abstract

AMHRII, the anti-Müllerian hormone receptor, is selectively expressed in normal sexual organs but is also re-expressed in gynecologic cancers. Hence, we developed murlentamab, a humanized glyco-engineered anti-AMHRII monoclonal antibody currently in clinical trial. Low-fucosylated antibodies are known to increase the antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) potency of effector cells, but some preliminary results suggest a more global murlentamab-dependent activation of the immune system. In this context, we demonstrate here that the murlentamab opsonization of AMHRII-expressing ovarian tumor cells, in the presence of unstimulated- or tumor-associated macrophage (TAM)-like macrophages, significantly promotes macrophage-mediated ADCC and shifts the whole microenvironment towards a pro-inflammatory and anti-tumoral status, thus triggering anti-tumor activity. We also report that murlentamab orients both unstimulated- and TAM-like macrophages to an M1-like phenotype characterized by a strong expression of co-stimulation markers, pro-inflammatory cytokines and chemokines, favoring T cell recruitment and activation. Moreover, we show that murlentamab treatment shifts CD4⁺ Th1/Th2 balance towards a Th1 response and activates CD8⁺ T cells. Altogether, these results suggest that murlentamab, through naïve macrophage orientation and TAM reprogrammation, stimulates the anti-tumor adaptive immune response. Those mechanisms might contribute to the sustained clinical benefit observed in advanced cancer patients treated with murlentamab. Finally, the enhanced murlentamab activity in combination with pembrolizumab opens new therapeutic perspectives.

The Expression of Anti-Müllerian Hormone Type II Receptor (AMHRII) in Non-Gynecological Solid Tumors Offers Potential for Broad Therapeutic Intervention in Cancer

Simple Summary

Until now, only a few studies have examined the AMHRII expression in tumors. Here, with more than 1000 tumor samples and using several complementary techniques we confirmed AMHRII expression in gynecological cancer and demonstrated AMHRII expression in certain non-gynecological cancers such as colorectal cancers. These findings open the way for new therapeutic approaches targeting AMHRII and emphasize the need to better understand the role of AMH/AMHRII in cancer.

Abstract

The anti-Müllerian hormone (AMH) belongs to the TGF-β family and plays a key role during fetal sexual development. Various reports have described the expression of AMH type II receptor (AMHRII) in human gynecological cancers including ovarian tumors. According to qRT-PCR results confirmed by specific In-Situ Hybridization (ISH) experiments, AMHRII mRNA is expressed in an extremely restricted number of normal tissues. By performing ISH on tissue microarray of solid tumor samples AMHRII mRNA was unexpectedly detected in several non-gynecological primary cancers including lung, breast, head and neck, and colorectal cancers. AMHRII protein expression, evaluated by immunohistochemistry (IHC) was detected in approximately 70% of epithelial ovarian cancers. Using the same IHC protocol on more than 900 frozen samples covering 18 different cancer types we detected AMHRII expression in more than 50% of hepato-carcinomas, colorectal, lung, and renal cancer samples. AMHRII expression was not observed in neuroendocrine lung tumor samples nor in non-Hodgkin lymphoma samples. Complementary analyses by immunofluorescence and flow cytometry confirmed the detection of AMHRII on a panel of ovarian and colorectal cancers displaying comparable expression levels with mean values of 39,000 and 50,000 AMHRII receptors per cell, respectively. Overall, our results suggest that this embryonic receptor could be a suitable target for treating AMHRII-expressing tumors with an anti-AMHRII selective agent such as murlentamab, also named 3C23K or GM102. This potential therapeutic intervention was confirmed in vivo by showing antitumor activity of murlentamab against AMHRII-expressing colorectal cancer and hepatocarcinoma Patient-Derived tumor Xenografts (PDX) models.

New Anti-Müllerian Hormone Target Genes Involved in Granulosa Cell Survival in Women With Polycystic Ovary Syndrome

PURPOSE

A protective effect of anti-Müllerian hormone (AMH) on follicle atresia was recently demonstrated using long-term treatments, but this effect has never been supported by mechanistic studies. This work aimed to gain an insight into the mechanism of action of AMH on follicle atresia and on how this could account for the increased follicle pool observed in women with polycystic ovary syndrome (PCOS).

METHODS

In vivo and in vitro experiments were performed to study the effects of AMH on follicle atresia and on the proliferation and apoptosis of granulosa cells (GCs). RNA-sequencing was carried out to identify new AMH target genes in GCs. The expression of some of these genes in GCs from control and PCOS women was compared using microfluidic real time quantitative RT-PCR.

RESULTS

A short-term AMH treatment prevented follicle atresia in prepubertal mice. Consistent with this result, AMH inhibited apoptosis and promoted proliferation of different models of GCs. Moreover, integrative biology analyses of 965 AMH target genes identified in 1 of these GC models, confirmed that AMH had initiated a gene expression program favoring cell survival and proliferation. Finally, on 43 genes selected among the most up- and down-regulated AMH targets, 8 were up-regulated in GCs isolated from PCOS women, of which 5 are involved in cell survival.

MAIN CONCLUSIONS

Our results provide for the first time cellular and molecular evidence that AMH protects follicles from atresia by controlling GC survival and suggest that AMH could participate in the increased follicle pool of PCOS patients.

Anti-Müllerian hormone (AMH) autocrine signaling promotes survival and proliferation of ovarian cancer cells

In ovarian carcinoma, anti-Müllerian hormone (AMH) type II receptor (AMHRII) and the AMH/AMHRII signaling pathway are potential therapeutic targets. Here, AMH dose-dependent effect on signaling and proliferation was analyzed in four ovarian cancer cell lines, including sex cord stromal/granulosa cell tumors and high grade serous adenocarcinomas (COV434-AMHRII, SKOV3-AMHRII, OVCAR8 and KGN). As previously shown, incubation with exogenous AMH at concentrations above the physiological range (12.5-25 nM) decreased cell viability. Conversely, physiological concentrations of endogenous AMH improved cancer cell viability. Partial AMH depletion by siRNAs was sufficient to reduce cell viability in all four cell lines, by 20% (OVCAR8 cells) to 40% (COV434-AMHRII cells). In the presence of AMH concentrations within the physiological range (5 to 15 pM), the newly developed anti-AMH B10 antibody decreased by 25% (OVCAR8) to 50% (KGN) cell viability at concentrations ranging between 3 and 333 nM. At 70 nM, B10 reduced clonogenic survival by 57.5%, 57.1%, 64.7% and 37.5% in COV434-AMHRII, SKOV3-AMHRII, OVCAR8 and KGN cells, respectively. In the four cell lines, B10 reduced AKT phosphorylation, and increased PARP and caspase 3 cleavage. These results were confirmed in ovarian cancer cells isolated from patients' ascites, demonstrating the translational potential of these results. Furthermore, B10 reduced COV434-MISRII tumor growth in vivo and significantly enhanced the median survival time compared with vehicle (69 vs 60 days; p = 0.0173). Our data provide evidence for a novel pro-survival autocrine role of AMH in the context of ovarian cancer, which was targeted therapeutically using an anti-AMH antibody to successfully repress tumor growth.

The regulation and signalling of anti-Müllerian hormone in human granulosa cells: relevance to polycystic ovary syndrome

STUDY QUESTION

What prevents the fall in anti-Müllerian hormone (AMH) levels in polycystic ovary syndrome (PCOS) and what are the consequences of this for follicle progression in these ovaries?

SUMMARY ANSWER

Exposure of granulosa cells (GCs) to high levels of androgens, equivalent to that found in PCOS, prevented the fall in AMH and was associated with dysregulated AMH-SMAD signalling leading to stalled follicle progression in PCOS.

WHAT IS KNOWN ALREADY

In normal ovaries, AMH exerts an inhibitory role on antral follicle development and a fall in AMH levels is a prerequisite for ovulation. Levels of AMH are high in PCOS, contributing to the dysregulated follicle growth that is a common cause of anovulatory infertility in these women.

STUDY DESIGN, SIZE, DURATION

Human KGN-GC (the cell line that corresponds to immature GC from smaller antral follicles (AF)) were cultured with a range of doses of various androgens to determine the effects on AMH production. KGN-GC were also treated with PHTPP (an oestrogen receptor β (ERβ) antagonist) to examine the relationship between AMH expression and the ratio of ERα:ERβ. The differential dose-related effect of AMH on gene expression and SMAD signalling was investigated in human granulosa-luteal cells (hGLC) from women with normal ovaries, with polycystic ovarian morphology (PCOM) and with PCOS. KGN-GC were also cultured for a prolonged period with AMH at different doses to assess the effect on cell proliferation and viability.

PARTICIPANTS/MATERIALS, SETTING, METHODS

AMH protein production by cells exposed to androgens was measured by ELISA. The effect of PHTPP on the mRNA expression levels of AMH, ERα and ERβ was assessed by real-time quantitative PCR (qPCR). The influence of AMH on the relative mRNA expression levels of aromatase, AMH and its receptor AMHRII, and the FSH and LH receptor (FSHR and LHR) in control, PCOM and PCOS hGLCs was quantified by qPCR. Western blotting was used to assess changes in levels of SMAD proteins (pSMAD-1/5/8; SMAD-4; SMAD-6 and SMAD-7) after exposure of hGLCs from healthy women and women with PCOS to AMH. The ApoTox-Glo Triplex assay was used to evaluate the effect of AMH on cell viability, cytotoxicity and apoptosis.

MAIN RESULTS AND THE ROLE OF CHANCE

Testosterone reduced AMH protein secreted from KGN-GC at 10-9-10-7 M (P < 0.05; P < 0.005, multiple uncorrected comparisons Fishers least squares difference), but at equivalent hyperandrogenemic levels no change was seen in AMH levels. 5α-DHT produced a significant dose-related increase in AMH protein secreted into the media (P = 0.022, ANOVA). Increasing the mRNA ratio of ERα:ERβ produced a corresponding increase in AMH mRNA expression (P = 0.015, two-way ANOVA). AMH increased mRNA levels of aromatase (P < 0.05, one-way ANOVA) and FSHR (P < 0.0001, one-way ANOVA) in hGLCs from women with PCOM, but not from normal cells or PCOS (normal n = 7, PCOM n = 5, PCOS n = 4). In contrast to hGLCs from ovulatory ovaries, in PCOS AMH reduced protein levels (cell content) of stimulatory pSMAD-1/5/8 and SMAD-4 but increased inhibitory SMAD-6 and -7 (P < 0.05, normal n = 6, PCOS n = 3). AMH at 20 and 50 ng/ml decreased KGN-GC cell proliferation but not viability after 8 days of treatment (P < 0.005, two-way ANOVA).

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Luteinised GC from women undergoing IVF have a relatively low expression of AMH/AMHRII but advantageously continue to display responses inherent to the ovarian morphology from which they are collected. To compensate, we also utilised the KGN cell line which has been characterised to be at a developmental stage close to that of immature GC. The lack of flutamide influence on testosterone effects is not in itself sufficient evidence to conclude that the effect on AMH is mediated via conversion to oestrogen, and the effect of aromatase inhibitors or oestrogen-specific inhibitors should be tested. The effect of flutamide was tested on testosterone but not DHT.

WIDER IMPLICATIONS OF THE FINDINGS

Normal folliculogenesis and ovulation are dependent on the timely reduction in AMH production from GC at the time of follicle selection. Our findings reveal for the first time that theca-derived androgens may play a role in this model but that this inhibitory action is lost at levels of androgens equivalent to those seen in PCOS. The AMH decline may either be a direct effect of androgens or an indirect one via conversion to oestradiol and acting through the upregulation of ERα, which is known to stimulate the AMH promoter. Interestingly, the ability of GCs to respond to this continually elevated AMH level appears to be reduced in cells from women with PCOS due to an adaptive alteration in the SMAD signalling pathway and lower expression of AMHRII, indicating a form of 'AMH resistance'.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the Thomas Addison Scholarship, St Georges Hospital Trust. The authors report no conflict of interest in this work and have nothing to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Highly elevated level of antimüllerian hormone associated with preterm delivery in polycystic ovary syndrome patients who underwent ovulation induction

OBJECTIVE

To determine the relationship between high antimüllerian hormone (AMH) levels and increased preterm delivery risk in populations of women with polycystic ovary syndrome (PCOS) or unexplained infertility undergoing ovulation induction.

DESIGN

Secondary analysis of data from two multicenter randomized clinical trials: Pregnancy in Polycystic Ovary Syndrome II (PPCOS II); and Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation (AMIGOS).

SETTING

Not applicable.

PATIENTS

Live births at ≥24 weeks' gestation from both the PPCOS II (n = 172) and AMIGOS (n = 222) cohorts were evaluated, and those at risk for iatrogenic preterm delivery including placental conditions, fetal growth restriction, multiple gestations, hypertensive diseases of pregnancy, and pre-gestational diabetes were excluded. The final analysis included 118 women with PCOS from the PPCOS II cohort and 146 women with unexplained infertility from the AMIGOS cohort.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Spontaneous preterm delivery.

RESULTS

In the PCOS population, median AMH overall was 5.5 ng/dL (interquartile range 2.9-9.3 ng/dL). In all, 62% of participants who delivered preterm had AMH levels above the 75th percentile. When comparing clinical covariates between the preterm and term deliveries, women with PCOS who delivered preterm had notably higher AMH than their term counterparts (11.1 vs. 5.4 ng/mL). In the univariate logistic regression analysis, each unit increase in AMH raised the odds of preterm delivery by 14% (odds ratio 1.14, 95% confidence interval 1.02-1.26). The effect was magnified only after adjusting for age, race, body mass index, smoking status, testosterone, homeostatic model assessment for insulin resistance, and treatment randomization group (adjusted odds ratio 1.25, 95% confidence interval 1.06-1.49). Unlike in the PCOS population, the unexplained infertility cohort had no significant difference in AMH levels between those with or without preterm delivery (2.3 vs. 2.6 ng/mL).

CONCLUSIONS

Our findings suggest that women with PCOS and high AMH who conceived after ovulation induction represent a high-risk group for preterm delivery. These data indicate that closer monitoring in the third trimester of pregnancies in PCOS patients with early first trimester AMH levels above 9.3 ng/mL may be warranted.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01044862.

Circulating CD14high CD16low intermediate blood monocytes as a biomarker of ascites immune status and ovarian cancer progression

BACKGROUND

Besides the interest of an early detection of ovarian cancer, there is an urgent need for new predictive and prognostic biomarkers of tumor development and cancer treatment. In healthy patients, circulating blood monocytes are typically subdivided into classical (85%), intermediate (5%) and non-classical (10%) populations. Although these circulating monocyte subsets have been suggested as biomarkers in several diseases, few studies have investigate their potential as a predictive signature for tumor immune status,tumor growth and treatment adaptation.

METHODS

In this study, we used a homogeneous cohort of 28 chemotherapy-naïve patients with ovarian cancer to evaluate monocyte subsets as biomarkers of the ascites immunological status. We evaluated the correlations between circulating monocyte subsets and immune cells and tumor burden in peritoneal ascites. Moreover, to validate the use of circulating monocyte subsets tofollow tumor progression and treatment response, we characterized blood monocytes from ovarian cancer patients included in a phase 1 clinical trial at baseline and following murlentamab treatment.

RESULTS

We demonstrate here a robust expansion of the intermediate blood monocytes (IBMs) in ovarian cancer patients. We establish a significant positive correlation between IBM percentage and tumor-associate macrophages with a CCR2high/CD163high/CD206high/CD86lowprofile. Moreover, IBM expansion is associated with a decreased effector/regulatory T-cell ratio in ascites and with the presence of soluble immunosuppressive mediators. We also establish that IBM proportion positively correlates with the peritoneum tumor burden. Finally, the study of IBMs in patients with ovarian cancer under immunotherapy during the phase clinical trial supports IBMs to follow the evolution of tumor development and the treatment adaptation.

CONCLUSIONS

This study, which links IBM level with immunosuppression and tumor burden in peritoneum, identifies IBMs as apotential predictive signature of ascites immune status and as a biomarker ofovarian cancer development and treatment response.

TRIAL REGISTRATION NUMBER

EudraCT: 2015-004252-22 NCT02978755.

Primary immunoprevention of adult onset cancers by vaccinating against retired tissue-specific self-proteins

Despite the enormous success of childhood prophylactic vaccination against diseases caused by pathogens, there is currently no similar preventive vaccine program against diseases confronted with age like breast cancer and ovarian cancer. With the exception of the annual influenza vaccine, current recommendations for adult vaccination are for either primary vaccines not received during childhood or for booster vaccinations to maintain the immunity against pathogens already induced during childhood. Here we describe a strategy to provide prophylactic pre-emptive immunity against the development of adult onset cancers not associated with any definitive etiopathogenic agent. We propose that safe and effective pre-emptive immunity may be induced in cancer-free subjects by vaccination against immunodominant tissue-specific self-proteins that are 'retired' from expression in normal tissues as part of the normal aging process but are expressed in tumors that emerge with age. Primary immunoprevention of adult onset cancers like breast cancer and ovarian cancer represents a great challenge and an even greater unmet need for our current healthcare.

Investigation of soluble anti-Müllerian hormone receptor type 2 as a biomarker for diagnosis of female fertility disorders

RESEARCH QUESTION

The ectodomain of the anti-Müllerian hormone (AMH) type 2 receptor is shed by proteases under certain conditions, which makes it measurable in the blood. The aim of this study was to identify correlations of soluble anti-Müllerian hormone receptor type 2 (sAMHR2) with other sex hormone concentrations and to assess whether sAMHR2 may serve as a new biomarker in fertility disorders.

DESIGN

In a retrospective cross-sectional study of women (n = 186) with different gynaecological-endocrinological disorders, mixed-effect models were used to analyse the correlation with established diagnostic hormone tests. Receiver operating characteristic curve analysis was performed to assess the diagnostic performance.

RESULTS

There was a strong correlation of sAMHR2 with LH (r = 0.898) and FSH (r = 0.846) and a moderate correlation of AMH with testosterone (r = 0.666) and androstenedione (r = 0.696) (all P < 0.001). In diagnoses of polycystic ovary syndrome (PCOS), AMH showed the best performance (area under the curve [AUC] 0.981, cut-off 4 ng/ml) with 96% sensitivity and 94% specificity. sAMHR2 concentrations and sAMHR2/AMH ratios were elevated in women with ovarian insufficiency, compared with all other study groups, including post-menopausal women on hormone replacement therapy. Highest sensitivity and specificity (100% and 98.2%, respectively) were achieved with sAMHR2/AMH ratio for the diagnosis of post-menopausal status (cut-off 68.85). The sAMHR2/AMH ratio (AUC 0.997) had a better performance than sAMHR2 (AUC 0.947), FSH (AUC 0.989) and LH (AUC 0.967).

CONCLUSIONS

The sAMHR2/AMH ratio may serve as a useful biomarker for infertility diagnostics to identify post-menopausal women.

ACVR1 Function in Health and Disease

Activin A receptor type I (ACVR1) encodes for a bone morphogenetic protein type I receptor of the TGFβ receptor superfamily. It is involved in a wide variety of biological processes, including bone, heart, cartilage, nervous, and reproductive system development and regulation. Moreover, ACVR1 has been extensively studied for its causal role in fibrodysplasia ossificans progressiva (FOP), a rare genetic disorder characterised by progressive heterotopic ossification. ACVR1 is linked to different pathologies, including cardiac malformations and alterations in the reproductive system. More recently, ACVR1 has been experimentally validated as a cancer driver gene in diffuse intrinsic pontine glioma (DIPG), a malignant childhood brainstem glioma, and its function is being studied in other cancer types. Here, we review ACVR1 receptor function and signalling in physiological and pathological processes and its regulation according to cell type and mutational status. Learning from different functions and alterations linked to ACVR1 is a key step in the development of interdisciplinary research towards the identification of novel treatments for these pathologies.

[Mullerian inhibiting substance type II receptor as a potential target for antineoplastic therapy]

The review considers properties of the type II anti-Mullerian hormone receptor (mullerian inhibiting substance receptor type II, MISRII), a transmembrane sensor with its own serine/threonine protein kinase activity, triggering apoptosis of the Mullerian ducts in mammalian embryogenesis and providing formation of the male type reproductive system. According to recent data, MISRII overexpression in the postnatal period is found in cells of a number of ovarian, mammary gland, and prostate tumors, and anti-Mullerian hormone (AMH) has a pro-apoptotic effect on MISRII-positive tumor cells. This fact makes MISRII a potential target for targeted anti-cancer therapy. Treatment based on targeting MISRII seems to be a much more effective alternative to the traditional one and will significantly reduce the drug dose. However, the mechanism of MISRII-AMH interaction is still poorly understood, so the development of new anticancer drugs is complicated. The review analyzes MISRII molecular structure and expression levels in various tissues and cell lines, as well as current understanding of the AMH binding mechanisms and data on the possibility of using MISRII as a target for the action of AMH-based antineoplastic drugs.

Anti-Müllerian Hormone Expression in Endometrial Cancer Tissue

Anti-Müllerian hormone (AMH) is a commonly known factor secreted by Sertoli cells, responsible for regression of the Müllerian ducts in male fetuses. AMH has also other functions in humans. In vivo and in vitro studies have shown that AMH inhibits cell cycle and induces apoptosis in cancers with AMH receptors. The aim of the study was to assess whether the tissue of pre-cancerous states of endometrium (PCS) and various histopathologic types of endometrial cancer (EC) exhibit the presence of AMH. We aimed to investigate whether the potential presence of the protein concerns menopausal women or those regularly menstruating, and whether is related to cancers with a good or a bad prognosis, as well as what other factors may influence AMH expression. The undertaken analysis was carried out on tissues retrieved from 232 women who underwent surgical treatment for PCS and EC. Tissues were prepared for immunohistochemical assessment with the use of a tissue microarrays method. AMH expression was confirmed in 23 patients with well differentiated endometrioid adenocarcinoma (G1), moderately differentiated endometrioid adenocarcinoma (G2), clear cell carcinoma (CCA) and nonatypical hyperplasia. AMH was not found in EC tissues in regularly menstruating women. An appropriately long mean period of breastfeeding in line with a prolonged period of hormonal activity had a positive effect on AMH expression. Our results may suggest that AMH is a factor which protects the organism against cancer, and should be further investigated as a potential prognosis marker and a therapeutic agent.

Vitamin D attenuates the effect of advanced glycation end products on anti-Mullerian hormone signaling

Vitamin D3 (1,25-dihydroxyvitamin D3, VD3) in vitro attenuates the effect of the pro-inflammatory advanced glycation end products (AGEs) on steroidogenesis in human granulosa cells (GCs) by downregulating the receptor for AGEs (RAGE). It has been shown that VD3 alone downregulates anti-Mullerian hormone (AMH) type 2 receptor (AMHR-2) gene expression and suppresses AMH-induced SMAD 1/5/8 phosphorylation in granulosa cells. However, the effect of AGEs, in the absence or presence of VD3, on AMH action in GCs has not been studied. Using human GCs, this study showed that human glycated albumin (HGA), an in vitro representative for AGEs, upregulated AMHR-2 mRNA but did not alter AMH mRNA expression levels. VD3 inhibited the HGA-induced increase in AMHR-2 mRNA expression levels. In KGN granulosa cell line, recombinant AMH induced SMAD 1/5/8 phosphorylation. HGA augmented the recombinant AMH-induced SMAD 1/5/8 phosphorylation while the addition of VD3 to HGA attenuated the recombinant AMH-induced SMAD 1/5/8 phosphorylation. Thus, AGEs could potentially affect folliculogenesis as reflected by changes in AMH signaling. These findings have significant implications for women with polycystic ovary syndrome who have significantly elevated serum and ovarian AGEs.

Hormone Replacement Therapy: Would it be Possible to Replicate a Functional Ovary?

Background: Throughout history, menopause has been regarded as a transition in a woman’s life. With the increase in life expectancy, women now spend more than a third of their lives in menopause. During these years, women may experience intolerable symptoms both physically and mentally, leading them to seek clinical advice. It is imperative for healthcare providers to improve the quality of life by reducing bothersome menopausal symptoms and preventing disorders such as osteoporosis and atherosclerosis. The current treatment in the form of hormone replacement therapy (HRT) is sometimes inadequate with several limitations and adverse effects. Objective and rationale: The current review aims to discuss the need, efficacy, and limitations of current HRT; the role of other ovarian hormones, and where we stand in comparison with ovary-in situ; and finally, explore towards the preparation of an HRT model by regeneration of ovaries tissues through stem cells which can replicate a functional ovary. Search methods: Four electronic databases (MEDLINE, Embase, Web of Science and CINAHL) were searched from database inception until 26 April 2018, using a combination of relevant controlled vocabulary terms and free-text terms related to ‘menopause’, ‘hormone replacement therapy’, ‘ovary regeneration’, ‘stem cells’ and ‘ovarian transplantation’. Outcomes: We present a synthesis of the existing data on the efficacy and limitations of HRT. HRT is far from adequate in postmenopausal women with symptoms of hormone deprivation as it fails to deliver all hormones secreted by naïve ovarian tissue. Moreover, the pharmacokinetics of synthetic hormones makes them substantially different from natural ones. Not only does the number and type of hormones given in HRT matter, but the route of delivering and their release in circulation are also imperative. The hormones are delivered either orally or topically in a non-physiological uniform manner, which brings along with it several side effects. These identify the need for a hormone delivery system which replicates, integrates and reacts as per the requirement of the female body. Wider implications: The review outlines the strengths and weaknesses of HRT and highlights the potential areas for future research. There is a tremendous potential for research in this field to understand the collective roles of the various ovarian hormones and to devise an auto-regulated hormone delivery system which replicates the normal physiology. Its clinical applications can prove to be transformative for postmenopausal women helping them to lead a healthy and productive life.

Anti-Müllerian hormone inhibits proliferation and induces apoptosis in epithelial ovarian cancer cells by regulating the cell cycle and decreasing the secretion of stem cell factor

Anti-Müllerian hormone (AMH) has been demonstrated to exhibit an inhibitory effect on the proliferation, invasion, metastasis and drug resistance of ovarian cancer. However, the mechanisms underlying these effects remain unclear. In the present study, 10 µg/ml recombinant human AMH (rhAMH) was administered to human OVCAR3 and OVCAR8 epithelial ovarian cancer (EOC) cell lines. Cell proliferation, apoptosis and cell cycle were analyzed. The level of stem cell factor (SCF) was detected using a reverse transcription-quantitative polymerase chain reaction and an ELISA, respectively. The exogenous addition of rhAMH significantly reduced the proliferation of OVCAR3 and OVCAR8 cell lines compared with the control group (P<0.01). The apoptosis rate in the rhAMH treated group (48 h) significantly increased compared with in the control group (OVCAR3, P=0.035; OVCAR8, P=0.020). The apoptosis rate increased at 72 h but did not exhibit a significant difference when compared with the 48 h group (OVCAR3, P=0.145; OVCAR8, P=0.296). The percentage of cells in the G₁ phase in the rhAMH treated group (48 h) increased but was not significantly different compared with the control group (OVCAR3, P=0.070; OVCAR8, P=0.051). However, there was a significant difference at 72 h compared with the control group (OVCAR3, P=0.016; OVCAR8, P=0.019). At 48 h, the rhAMH-treated group exhibited a statistically significant inhibition of SCF mRNA expression levels (P=0.008), but no significant difference in the protein expression levels (P=0.101) compared with the control, though a significant inhibition was exhibited at 72 h (mRNA expression levels, P=0.005; protein expression levels, P=0.036). The present study revealed that rhAMH may be able to inhibit the proliferation and induce the apoptosis of EOC cells via G₁/S-phase cell cycle arrest and the decreased secretion of SCF.

The anti-tumor efficacy of 3C23K, a glyco-engineered humanized anti-MISRII antibody, in an ovarian cancer model is mainly mediated by engagement of immune effector cells

Ovarian cancer is the leading cause of death in women with gynecological cancers and despite recent advances, new and more efficient therapies are crucially needed. Müllerian Inhibiting Substance type II Receptor (MISRII, also named AMHRII) is expressed in most ovarian cancer subtypes and is a novel potential target for ovarian cancer immunotherapy. We previously developed and tested 12G4, the first murine monoclonal antibody (MAb) against human MISRII. Here, we report the humanization, affinity maturation and glyco-engineering steps of 12G4 to generate the Fc-optimized 3C23K MAb, and the evaluation of its in vivo anti-tumor activity. The epitopes of 3C23K and 12G4 were strictly identical and 3C23K affinity for MISRII was enhanced by a factor of about 14 (K_D = 5.5 × 10⁻¹¹ M vs 7.9 × 10⁻¹⁰ M), while the use of the EMABling^® platform allowed the production of a low-fucosylated 3C23K antibody with a 30-fold K_D improvement of its affinity to FcγRIIIa. In COV434-MISRII tumor-bearing mice, 3C23K reduced tumor growth more efficiently than 12G4 and its combination with carboplatin was more efficient than each monotherapy with a mean tumor size of 500, 1100 and 100 mm³ at the end of treatment with 3C23K (10 mg/kg, Q3-4D12), carboplatin (60 mg/kg, Q7D4) and 3C23K+carboplatin, respectively. Conversely, 3C23K-FcKO, a 3C23K form without affinity for the FcγRIIIa receptor, did not display any anti-tumor effect in vivo. These results strongly suggested that 3C23K mechanisms of action are mainly Fc-related. In vitro, antibody-dependent cytotoxicity (ADCC) and antibody-dependent cell phagocytosis (ADCP) were induced by 3C23K, as demonstrated with human effector cells. Using human NK cells, 50% of the maximal lysis was obtained with a 46-fold lower concentration of low-fucosylated 3C23K (2.9 ng/ml) than of 3C23K expressed in CHO cells (133.35 ng/ml). As 3C23K induced strong ADCC with human PBMC but almost none with murine PBMC, antibody-dependent cell phagocytosis (ADCP) was then investigated. 3C23K-dependent (100 ng/ml) ADCP was more active with murine than human macrophages (only 10% of living target cells vs. about 25%). These in vitro results suggest that the reduced ADCC with murine effectors could be partially balanced by ADCP activity in in vivo experiments. Taken together, these preclinical data indicate that 3C23K is a new promising therapeutic candidate for ovarian cancer immunotherapy and justify its recent introduction in a phase I clinical trial.

The molecular mechanism of ovarian granulosa cell tumors

Over these years, more and more sex cord-stromal tumors have been reported. Granulosa cell tumor (GCT) is a rare tumor in ovaries, accounts for 2% to 5% of ovarian cancers. The main different feature of GCTs from other ovarian cancers is that GCTs can lead to abnormally secreted hormones (estrogen, inhibin and Müllerian inhibiting substance). The GCT is divided into two categories according to the age of patients, namely AGCT (adult granulosa cell tumor) and JGCT (Juvenile granulosa cell tumor). AGCT patients accounts for 95%. Although the pathogenesis is not clear, FOXL2 (Forkhead box L2) mutation was considered as the most critical factor in AGCT development. The current treatment is dominated by surgery. Target therapy remains in the adjuvant therapy stage, such as hormone therapy. During these years, other pathogenic factors were also explored, such as PI3K/AKT (phosphatidylinositol-3-kinase; serine/threonine kinase), TGF-β (Transforming growth factor beta) signaling pathway, Notch signaling pathway, GATA4 and VEGF (vascular endothelial growth factor). These factors and signaling pathway play important roles in GCT cell proliferation, apoptosis, or angiogenesis. The purpose of this review is to summarize the possible pathogenic factors and signaling pathways, which may shed lights on developing potential therapeutic targets for GCT.

Role and mechanism of AMH in the regulation of Sertoli cells in mice

Sertoli cells produce anti-Müllerian hormone (AMH), a glycoprotein belonging to the transforming growth factor-beta family. AMH mediates the regression of Müllerian ducts in the developing male fetus. However, the role of AMH in the regulation of primary Sertoli cells remains unclear. The present study was designed to investigate the effect of AMH on the viability and proliferation of Sertoli cells, with an additional focus on stem cell factor (SCF). Treatment of Sertoli cells with increasing concentrations of rh-AMH (0, 10, 50, 100, and 800ng/ml) for two days revealed that AMH, at high concentrations, increased apoptosis. These results were confirmed by a significant increase in Caspase-3 and Bax and a decrease in Bcl-2 protein and mRNA expression (P<0.01). Paradoxically, treatment with a low concentration of rh-AMH (10ng/ml), but not higher concentrations (50-800ng/ml), promoted Sertoli cell proliferation, which was verified by an increase in PCNA mRNA (P<0.05). Furthermore, only low concentrations of rh-AMH activated the non-canonical ERK signaling pathway. Similarly, low concentrations of rh-AMH (10-50ng/ml) significantly increased (P<0.05) SCF mRNA and SCF protein levels. These findings indicate that AMH differentially regulates the fate of Sertoli cells in vitro by promoting proliferation at low concentrations and apoptosis at high concentrations. In addition, AMH increased the expression of SCF, an important regulator of Sertoli cell development. Therefore, AMH may play a role in Sertoli cell development.

The humanized anti-human AMHRII mAb 3C23K exerts an anti-tumor activity against human ovarian cancer through tumor-associated macrophages

Müllerian inhibiting substance, also called anti-Müllerian hormone (AMH), inhibits proliferation and induces apoptosis of AMH type II receptor-positive tumor cells, such as human ovarian cancers (OCs). On this basis, a humanized glyco-engineered monoclonal antibody (3C23K) has been developed. The aim of this study was therefore to experimentally confirm the therapeutic potential of 3C23K in human OCs. We first determined by immunofluorescence, immunohistochemistry and cytofluorometry analyses the expression of AMHRII in patient’s tumors and found that a majority (60 to 80% depending on the detection technique) of OCs were positive for this marker. We then provided evidence that the tumor stroma of OC is enriched in tumor-associated macrophages and that these cells are responsible for 3C23K-induced killing of tumor cells through ADCP and ADCC mechanisms. In addition, we showed that 3C23K reduced macrophages induced-T cells immunosuppression. Finally, we evaluated the therapeutic efficacy of 3C23K alone and in combination with a carboplatin-paclitaxel chemotherapy in a panel of OC Patient-Derived Xenografts. In those experiments, we showed that 3C23K significantly increased the proportion and the quality of chemotherapy-based in vivo responses. Altogether, our data support the potential interest of AMHRII targeting in human ovarian cancers and the evaluation of 3C23K in further clinical trials.

Pathogenesis and treatment of adult-type granulosa cell tumor of the ovary

Adult-type granulosa cell tumor is a clinically and molecularly unique subtype of ovarian cancer. These tumors originate from the sex cord stromal cells of the ovary and represent 3-5% of all ovarian cancers. The majority of adult-type granulosa cell tumors are diagnosed at an early stage with an indolent prognosis. Surgery is the cornerstone for the treatment of both primary and relapsed tumor, while chemotherapy is applied only for advanced or non-resectable cases. Tumor stage is the only factor consistently associated with prognosis. However, every third of the patients relapse, typically in 4-7 years from diagnosis, leading to death in 50% of these patients. Anti-Müllerian Hormone and inhibin B are currently the most accurate circulating biomarkers. Adult-type granulosa cell tumors are molecularly characterized by a pathognomonic somatic missense point mutation 402C->G (C134W) in the transcription factor FOXL2. The FOXL2 402C->G mutation leads to increased proliferation and survival of granulosa cells, and promotes hormonal changes. Histological diagnosis of adult-type granulosa cell tumor is challenging, therefore testing for the FOXL2 mutation is crucial for differential diagnosis. Large international collaborations utilizing molecularly defined cohorts are essential to improve and validate new treatment strategies for patients with high-risk or relapsed adult-type granulosa cell tumor. Key Messages: Adult-type granulosa cell tumor is a unique ovarian cancer with an indolent, albeit unpredictable disease course. Adult-type granulosa cell tumors harbor a pathognomonic somatic missense mutation in transcription factor FOXL2. The key challenges in the treatment of patients with adult-type granulosa cell tumor lie in the identification and management of patients with high-risk or relapsed disease.

Investigation of factors affecting the efficacy of 3C23K, a human monoclonal antibody targeting MISIIR

MISIIR is a potential target for ovarian cancer (OC) therapy due to its tissue-specific pattern of expression. 3C23K is a novel therapeutic monoclonal anti-MISIIR antibody designed to recruit effector cells and promote cell death through ADCC (antibody dependent cell-mediated cytotoxicity). Our objective was to determine the tolerability and efficacy of 3C23K in OC patient-derived xenografts (PDX) and to identify factors affecting efficacy. Quantitative RT-PCR, immunohistochemistry (IHC), and flow cytometry were used to categorize MISIIR expression in established PDX models derived from primary OC patients. We selected two high expressing models and two low expressing models for in vivo testing. One xenograft model using an MISIIR over-expressing SKOV3ip cell line (Z3) was a positive control. The primary endpoint was change in tumor size. The secondary endpoint was final tumor mass. We observed no statistically significant differences between control and treated animals. The lack of response could be secondary to a number of variables including the lack of known biomarkers of response, the low membrane expression of MISIIR, and a limited ability of 3C23K to induce ADCC in PDX models. Further study is needed to determine the magnitude of ovarian cancer response to 3C23K and also if there is a threshold surface expression to predict response.

Anti-Müllerian Hormone Signaling Regulates Epithelial Plasticity and Chemoresistance in Lung Cancer

Anti-Müllerian hormone (AMH) and its type II receptor AMHR2, both previously thought to primarily function in gonadal tissue, were unexpectedly identified as potent regulators of transforming growth factor (TGF-β)/bone morphogenetic protein (BMP) signaling and epithelial-mesenchymal transition (EMT) in lung cancer. AMH is a TGF-β/BMP superfamily member, and AMHR2 heterodimerizes with type I receptors (ALK2, ALK3) also used by the type II receptor for BMP (BMPR2). AMH signaling regulates expression of BMPR2, ALK2, and ALK3, supports protein kinase B-nuclear factor κB (AKT-NF-κB) and SMAD survival signaling, and influences BMP-dependent signaling in non-small cell lung cancer (NSCLC). AMH and AMHR2 are selectively expressed in epithelial versus mesenchymal cells, and loss of AMH/AMHR2 induces EMT. Independent induction of EMT reduces expression of AMH and AMHR2. Importantly, EMT associated with depletion of AMH or AMHR2 results in chemoresistance but sensitizes cells to the heat shock protein 90 (HSP90) inhibitor ganetespib. Recognition of this AMH/AMHR2 axis helps to further elucidate TGF-β/BMP resistance-associated signaling and suggests new strategies for therapeutic targeting of EMT.

The human Müllerian inhibiting substance type II receptor as immunotherapy target for ovarian cancer. Validation using the mAb 12G4

Ovarian cancer has the highest mortality rate among gynecologic malignancies. The monoclonal antibody 12G4 specifically recognizes the human Müllerian inhibiting substance type II receptor (MISRII) that is strongly expressed in human granulosa cell tumors (GCT) and in the majority of human epithelial ovarian cancers (EOC). To determine whether MISRII represents an attractive target for antibody-based tumor therapy, we first confirmed by immunohistochemistry with 12G4 its expression in all tested GCT samples (4/4) and all, but one, EOC human tissue specimens (13/14). We then demonstrated in vitro the internalization of 12G4 in MISRII(high)COV434 cells after binding to MISRII and its ability to increase the apoptosis rate (FACS, DNA fragmentation) in MISRII(high)COV434 (GCT) and MISRII(medium)NIH-OVCAR-3 (EOC) cells that express different levels of MISRII. A standard (51)Cr release assay showed that 12G4 mediates antibody-dependent cell-meditated cytotoxicity. Finally, in vivo assessment of 12G4 anti-tumor effects showed a significant reduction of tumor growth and an increase of the median survival time in mice xenografted with MISRII(high)COV434 or MISRII(medium)NIH-OVCAR-3 cells and treated with 12G4 in comparison to controls treated with an irrelevant antibody. Altogether, our data indicate that MISRII is a new promising target for the control of ovarian GCTs and EOCs. A humanized version of the 12G4 antibody, named 3C23K, is in development for the targeted therapy of MISRII-positive gynecologic cancers.

Evidence of Spontaneous Recovery of Granulosa-Theca Cell Tumour in a Heifer: A Retrospective Report

A 14-month-old Japanese Black heifer was evaluated on Day 0 (D 0) for enlargement of the right ovary (RO). Transrectal ultrasonography (TRUS) revealed that the RO was markedly enlarged and multicystic, while the left ovary (LO) was small and inactive. The presumptive diagnosis was granulosa-theca cell tumour (GTCT), which was confirmed by markedly elevated plasma anti-Müllerian hormone (AMH) of 4.42 ng/ml. Therefore, ovariectomy of the RO was the treatment of choice. The heifer was checked by TRUS and blood sampling on D 42, D 63 and immediately before ovariectomy on D 85. On D 42, TRUS did not show marked changes in either ovary in comparison with D 0. However, on D 63, the RO had transformed into a single cyst, and on D 85, the LO had resumed cyclic activity. The RO was extracted on D 85 by hand-assisted laparoscopic ovariectomy to allow better control. Unexpectedly, histopathology revealed the lesion to be a fluid-filled cystic structure, with no neoplastic proliferation of follicular epithelium that would indicate GTCT. The wall of the cystic structure consisted of collagen fibres and a few degenerated granulosa cells. The retrospective hormonal analysis revealed that the AMH concentrations had markedly dropped on D 63 and 85, which coincided with resumption of cyclicity in the LO. These findings suggest that the GTCT had self-cured and transformed into a cyst-like structure. The heifer then received an oestrous synchronization regime on D 105, was artificially inseminated on D 115 and became pregnant.

Effect of Anti-Müllerian hormone (AMH) and bone morphogenetic protein 15 (BMP-15) on steroidogenesis in primary-cultured human luteinizing granulosa cells through Smad5 signalling

PURPOSE

To determine if there is any effect of AMH and BMP-15 on estradiol and progesterone production from primary-cultured human luteinizing granulosa cells, to delineate what is the effect of FSH on their actions and which are the possible mechanisms involved.

METHODS

Luteinizing granulosa cells (GCs), obtained from follicular fluid of 30 women undergoing in vitro fertilization, were cultured, after a short 24-h preincubation period, in serum-free medium for 24 or/and 48 h in the presence/absence of various concentrations of AMH, BMP-15 and FSH alone or in combinations. Estradiol and progesterone production, SMAD5 phosphorylation and StAR expression were studied in parallel. Steroids were measured in culture-supernatant using enzyme-immunoassays, while Smad5-signaling pathway activation and StAR protein expression were assessed immunocytochemically.

RESULT(S)

We found that the treatment of AMH in GCs for 24/48 h attenuated FSH-induced estradiol production (p < 0.001), had no effect on basal estradiol levels, decreased basal progesterone production (p < 0.001) and FSH-induced StAR expression (p < 0.001). On the other hand, BMP-15 decreased basal estradiol levels (p < 0.001) and attenuated FSH-induced estradiol production (p < 0.001). Furthermore, BMP-15 reduced progesterone basal secretion (p < 0.001), an effect that was partially reversed by FSH (p < 0.01), probably via increasing StAR expression (p < 0.001). FSH-induced StAR expression was also attenuated by BMP-15 (p < 0.001). FSH, AMH and BMP-15 activated Smad-signaling pathway, as confirmed by the increase of phospo-Smad5 protein levels (p < 0.001 compared to control).

CONCLUSION(S)

AMH and BMP-15 by interacting with FSH affect the production of estradiol and progesterone from cultured luteinizing-granulosa cells possibly via Smad5-protein phosphorylation.

The clinical utility of serum anti-Müllerian hormone in the follow-up of ovarian adult-type granulosa cell tumors--A comparative study with inhibin B

Ovarian adult-type granulosa cell tumors (AGCTs) require prolonged follow-up, but evidence regarding the optimal follow-up marker is lacking. The objective of our study was to validate the clinical usefulness of serum anti-Müllerian hormone (AMH) and the current marker inhibin B as single and combined markers of AGCTs. We conducted a longitudinal, partially prospective cohort study of 123 premenopausal and postmenopausal AGCT patients with a median follow-up time of 10.5 years (range 0.3-50.0 years). Serum AMH and inhibin B levels were measured from 560 pretreatment and follow-up serum samples by using immunoenzymometric assays. We found that serum AMH and inhibin B levels were significantly elevated in patients with primary or recurrent AGCTs. The levels of both markers positively correlated to tumor size (p < 0.05). AMH and inhibin B performed similarly in receiving operator characteristic analyses; area under the curve (AUC) values were 0.92 [95% confidence interval (CI) 0.88-0.95] for AMH, and 0.94 (95% CI 0.90-0.96) for inhibin B. AMH was highly sensitive (92%) and specific (81%) in detecting a macroscopic AGCT. However, in AUC comparison analyses, the combination of the markers was superior to inhibin B alone. In conclusion, serum AMH is a sensitive and specific marker of AGCT, and either AMH or inhibin B can be monitored during follow-up. However, combining AMH and inhibin B in AGCT patient follow-up improves the detection of recurrent disease.

[What's new in 2014 about anti-Müllerian hormone?]

The existence of the anti-Müllerian hormone (AMH) has been postulated by Professor Alfred Jost to explain the regression of the Müllerian ducts during male sexual differentiation. Since then, AMH has been purified, its gene and specific receptor, AMHR-II have been cloned. Further, the signaling pathways were identified and it has been observed that AMH was produced by the granulosa cells of growing follicles. From the 2000s, unexpected roles of AMH have been highlighted, reactivating international research on this hormone. It is now well established that AMH plays a key role in the follicular recruitment and development. Over the past years, serum AMH measurements have been proposed as a marker of the follicular ovarian status, and a predictor of assisted reproductive cycles. AMH is also useful to assess the effectiveness of treatment of some gynecological tumors. This article is a review of the past five years advances on the regulation of the expression of AMH and its specific receptor AMHR-II in female.

HER2 and GATA4 are new prognostic factors for early-stage ovarian granulosa cell tumor-a long-term follow-up study

Granulosa cell tumors (GCTs) carry a risk of recurrence also at an early stage, but reliable prognostic factors are lacking. We assessed clinicopathological prognostic factors and the prognostic roles of the human epidermal growth factor receptors (HER 2–4) and the transcription factor GATA4 in GCTs. We conducted a long-term follow-up study of 80 GCT patients with a mean follow-up time of 16.8 years. A tumor-tissue microarray was immunohistochemically stained for HER2–4 and GATA4. Expression of HER2–4 mRNA was studied by means of real time polymerase chain reaction and HER2 gene amplification was analyzed by means of silver in situ hybridization. The results were correlated to clinical data on recurrences and survival. We found that GCTs have an indolent prognosis, with 5-year disease-specific survival (DSS) being 97.5%. Tumor recurrence was detected in 24% of the patients at a median of 7.0 years (range 2.6–18 years) after diagnosis. Tumor stage was not prognostic of disease-free survival (DFS). Of the molecular prognostic factors, high-level expression of HER2, and GATA4, and high nuclear atypia were prognostic of shorter DFS. In multivariate analyses, high-level coexpression of HER2 and GATA4 independently predicted DFS (hazard ratio [HR] 8.75, 95% CI 2.20–39.48, P = 0.002). High-level expression of GATA4 also predicted shorter DSS (HR 3.96, 95% CI 1.45–12.57, P = 0.006). In multivariate analyses, however, tumor stage (II–III) and nuclear atypia were independent prognostic factors of DSS. In conclusion HER2 and GATA4 are new molecular prognostic markers of GCT recurrence, which could be utilized to optimize the management and follow-up of patients with early-stage GCTs.