Müllerian inhibiting substance type II receptor (MISIIR): a novel, tissue-specific target expressed by gynecologic cancers

AMH regulates a mosaic population of AMHR2-positive cells in the ovarian surface epithelium

The function and homeostasis of the mammalian ovary depend on complex paracrine interactions between multiple cell types. Using primary mouse tissues and isolated cells, we showed in vitro that ovarian follicles secrete a factor(s) that suppresses growth of ovarian epithelial cells in culture. Most of the growth suppressive activity was accounted for by Anti-Mullerian Hormone/Mullerian Inhibitory Substance (AMH/MIS) secreted by granulosa cells of the follicles, as determined by immune depletion experiments. Additionally, conditioned medium from granulosa cells from wild type control, but not AMH knockout, suppressed epithelial cell growth. Tracing of the AMH regulated cells using AMHR2 (AMH receptor 2)-Cre:ROSA26 mutant mice indicated the presence of populations of AMHR2-positive epithelial cells on the ovarian surface and oviduct epithelia. Cells isolated from the mutant mice indicated that a subpopulation of cells marked by AMHR2-Cre:ROSA26 accounted for most cell growth and expansion in ovarian surface epithelial cells, and the AMHR2 lineage derived cells were regulated by AMH in vitro; whereas, fewer AMHR2-Cre:ROSA26 marked cells accounted for oviduct epithelial cell outgrowth. The results reveal a paracrine pathway in maintaining follicle-epithelial homeostasis in ovary and support a subpopulation of AMHR2 lineage marked epithelial cells as ovarian epithelial stem/progenitor cells with higher proliferative potential regulatable by follicle secreted AMH.

Anti-Müllerian hormone type II receptor protein expression in non-small cell lung cancer and the effect of AMH/AMHR2 signaling on cancer cell proliferation

BACKGROUND

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related deaths worldwide despite advances in cancer therapeutics. In several gynecological cancers, anti-Müllerian hormone receptor type 2 (AMHR2) mediates AMH-induced growth inhibition and is expressed at high levels. Furthermore, 5%-8% of NSCLCs exhibit high AMHR2 expression, suggesting that AMH may inhibit the progression of some lung cancers. However, the clinical relevance of AMHR2 expression and its role in lung cancer is not fully clarified.

METHODS

Immunostaining was performed on 79 surgical specimens of NSCLC. The Cancer Genome Atlas RNA-seq data for lung adenocarcinoma were analyzed, and gene ontology and gene set enrichment analyses were performed. In cellular experiments, AMHR2-overexpressing NSCLC cell lines were established, and the role of the AMH-AMHR2 pathway in cell proliferation with recombinant human AMH protein treatment was examined.

RESULTS

A total of 13 cases (16.5%) were positive for immunostaining in lung adenocarcinoma tissues; no positive signals were detected in lung squamous carcinoma tissues. Gene expression variation analysis using The Cancer Genome Atlas data showed that the expression of genes related to the cell cycle was downregulated in the AMHR2-high group. Cellular experiments showed that activation of the AMH-AMHR2 pathway suppressed cell proliferation.

CONCLUSION

In lung adenocarcinoma tissues with high expression of AMHR2, activation of the AMH-AMHR2 pathway may suppress cell proliferation.

CAR-T Cell Therapy in Ovarian Cancer: Where Are We Now?

The success of chimeric antigen receptor T-cell (CAR-T) therapies in the treatment of hematologic malignancies has led to the investigation of their potential in the treatment of solid tumors, including ovarian cancer. While the immunosuppressive microenvironment of ovarian cancer has been a barrier in their implementation, several early phase clinical trials are currently evaluating CAR-T cell therapies targeting mesothelin, folate receptor a, HER2, MUC16, and B7H3. Ongoing challenges include cytokine-associated and "on-target, off-tumor" toxicities, while most common adverse events include cytokine release syndrome, hemophagocytic lymphohistiocytosis/macrophage activation-like syndrome (HLH/MAS), and neurotoxicity. In the present review, we summarize the current status of CAR-T therapy in ovarian cancer and discuss future directions.

Facts and Hopes in Immunotherapy of Endometrial Cancer

Immunotherapy with checkpoint inhibitors has changed the paradigm of treatment for many tumors, and endometrial carcinoma is not an exception. Approved treatment options are pembrolizumab or dostarlimab for mismatch repair deficient tumors, pembrolizumab for tumors with high mutational load, and, more recently, pembrolizumab/lenvatinib for all patients with endometrial cancer. Endometrial cancer is a heterogeneous disease with distinct molecular subtypes and different prognoses. Differences between molecular subgroups regarding antigenicity and immunogenicity should be relevant to develop more tailored immunotherapeutic approaches. In this review, we aim to summarize and discuss the current evidence-Facts, and future opportunities-Hopes-of immunotherapy for endometrial cancer, focusing on relevant molecular and tumor microenvironment features of The Cancer Genome Atlas endometrial cancer subtypes.

Formulation of an ovarian cancer vaccine with the squalene-based AddaVax adjuvant inhibits the growth of murine epithelial ovarian carcinomas

Purpose

Epithelial ovarian carcinoma (EOC) is the most lethal of all human gynecologic malignancies. We previously reported that vaccination of female mice with the extracellular domain of anti-Müllerian hormone receptor II (AMHR2-ED) in complete Freund’s adjuvant (CFA) generates AMHR2-ED specific immunoglobulin G (IgG) that provides prevention and therapy against murine EOCs. Although CFA is the “gold standard” adjuvant in animal studies, it is not approved for human use because it often induces painful granulomas and abscesses. Thus, the objective of this study is to identify an alternative adjuvant to CFA for use in our ovarian cancer vaccine clinical trials.

Materials and Methods

Because it has been used successfully without serious adverse effects in numerous human clinical trials, we selected the IgG-inducing squalene-based adjuvant, AddaVax™, for evaluation of its ability to facilitate vaccine-induced prevention and treatment of EOC in mice. To this end, we immunized female C57BL/6 mice with recombinant mouse AMHR2-ED emulsified with either AddaVax or CFA as adjuvant and compared the results.

Results

We found that formulation of the AMHR2-ED vaccine with AddaVax adjuvant induced high serum titers of IgG and significant inhibition of EOC growth with significantly enhanced overall survival of mice using both prevention and therapeutic protocols. These results were compared favorably with results obtained using CFA as an adjuvant in the AMHR2-ED vaccine.

Conclusion

Our data indicate that the AMHR2-ED vaccine formulated with AddaVax may be used in human clinical trials and thereby serve as a novel and effective way to control human EOC.

A novel method for purification of biologically active C-terminal fragment of human recombinant anti-mullerian hormone

Anti-mullerian hormone (AMH) is one of the least studied members of transforming growth factor beta superfamily showing pro-apoptotic activity against cells positive for hormone type II receptor overexpressed by malignant cells in many cancer cases. Here, we propose an improved method for isolation of recombinant C-terminal AMH fragment (C-rAMH) to obtain homogeneous preparations of this protein with high biological activity. In contrast to our previously developed C-rAMH purification technology based on reversed-phase HPLC, the key stage of the new approach is hydrophobic interaction chromatography using Toyopearl Butyl-650S resin performed under more benign conditions. This modification of the previously developed method allowed highly purified C-rAMH to be obtained that is characterized by twice the specificity estimated as the ability to bind to the recombinant analog of AMH type II receptor and by significantly higher biological activity, that is, the ability to induce the death of target cells. Thus, we made the purification technology even more cost-effective and suitable for the production of drug forms based on C-rAMH.

The state of the art of bispecific antibodies for treating human malignancies

Bispecific antibodies (bsAb) that target two independent epitopes or antigens have been extensively explored in translational and clinical studies since they were first developed in the 1960s. Many bsAbs are being tested in clinical trials for treating a variety of diseases, mostly cancer. Here, we provide an overview of various types of bsAbs in clinical studies and discuss their targets, safety profiles, and efficacy. We also highlight the current challenges, potential solutions, and future directions of bsAb development for cancer treatment.

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.

Immunotherapy in endometrial cancer: rationale, practice and perspectives

Tumor immunotherapy has attracted more and more attention nowadays, and multiple clinical trials have confirmed its effect in a variety of solid tumors. Immune checkpoint inhibitors (ICIs), cancer vaccines, adoptive cell transfer (ACT), and lymphocyte-promoting cytokines are the main immunotherapy methods. Endometrial cancer (EC) is one of the most frequent tumors in women and the prognosis of recurrent or metastatic EC is poor. Since molecular classification has been applied to EC, immunotherapy for different EC subtypes (especially POLE and MSI-H) has gradually attracted attention. In this review, we focus on the expression and molecular basis of the main biomarkers in the immunotherapy of EC firstly, as well as their clinical application significance and limitations. Blocking tumor immune checkpoints is one of the most effective strategies for cancer treatment in recent years, and has now become the focus in the field of tumor research and treatment. We summarized clinical date of planned and ongoing clinical trials and introduced other common immunotherapy methods in EC, such as cancer vaccine and ACT. Hormone aberrations, metabolic syndrome (MetS) and p53 mutant and that affect the immunotherapy of endometrial cancer will also be discussed in this review.

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.

[The study of interaction of different forms of human recombinant anti-mullerian hormone with a chimeric analogue of the AMH type II]

The homodimeric glycoprotein, anti-mullerian hormone (AMH), described over 70 years ago by A. Jost, is the least studied member of the transforming growth factor beta superfamily. Despite the antitumor activity of AMH discovered at the end of the last century, the creation of effective drugs based on AMH is hindered primarily by the lack of information on the mechanism of various AMH forms interaction with a specific type II receptor (MISRII). Previously, we have shown that not only the full-length activated hormone but also its C-terminal fragment (C-rAMH) could bind to MISRII. In this work, using the surface plasmon resonance technique, we compared the interaction of three forms of recombinant AMH (rAMH) with the MISRII analogue - the chimeric protein MISRII-Fc containing AMH type II receptor and a Fc-fragment of the human IgG1 heavy chain. Comparison of the binding of MISRII-Fc, immobilized on a chip with group specificity for human immunoglobulins, to C-rAMH, to intact rAMH (pro-rAMH), and to rAMH containing one uncleaved monomer (hc-rAMH), showed that the KD of the complexes increased: 1.7 nM, 88 nM and 110 nM, respectively. Thus, we have shown that C-terminal fragment of AMH has the maximum affinity for the recombinant MISRII analogue, which indicates the prospects for the development of drugs based on this hormone derivative.

Anti-Müllerian hormone levels and risk of type 2 diabetes in women

AIMS/HYPOTHESIS

Given its role in ovarian follicle development, circulating anti-Müllerian hormone (AMH) is considered to be a marker of reproductive ageing. Although accelerated reproductive ageing has been associated with a higher risk of type 2 diabetes, research on the relationship between AMH and type 2 diabetes risk is scarce. Therefore, we aimed to investigate whether age-specific AMH levels and age-related AMH trajectories are associated with type 2 diabetes risk in women.

METHODS

We measured AMH in repeated plasma samples from 3293 female participants (12,460 samples in total), aged 20-59 years at recruitment, from the Doetinchem Cohort Study, a longitudinal study with follow-up visits every 5 years. We calculated age-specific AMH tertiles at baseline to account for the strong AMH-age correlation. Cox proportional hazards models adjusted for confounders were used to assess the association between baseline age-specific AMH tertiles and incident type 2 diabetes. We applied linear mixed models to compare age-related AMH trajectories for women who developed type 2 diabetes with trajectories for women who did not develop diabetes.

RESULTS

During a median follow-up of 20 years, 163 women developed type 2 diabetes. Lower baseline age-specific AMH levels were associated with a higher type 2 diabetes risk (HR_T2vsT3 1.24 [95% CI 0.81, 1.92]; HR_T1vsT3 1.62 [95% CI 1.06, 2.48]; p_trend = 0.02). These findings seem to be supported by predicted AMH trajectories, which suggested that plasma AMH levels were lower at younger ages in women who developed type 2 diabetes compared with women who did not. The trajectories also suggested that AMH levels declined at a slower rate in women who developed type 2 diabetes, although differences in trajectories were not statistically significant.

CONCLUSIONS/INTERPRETATION

We observed that lower age-specific AMH levels were associated with a higher risk of type 2 diabetes in women. Longitudinal analyses did not show clear evidence of differing AMH trajectories between women who developed type 2 diabetes compared with women who did not, possibly because these analyses were underpowered. Further research is needed to investigate whether AMH is part of the biological mechanism explaining the association between reproductive ageing and type 2 diabetes. Graphical abstract.

Anti-Müllerian Hormone Levels and Risk of Cancer in Women

OBJECTIVES

To examine if age-specific anti-Müllerian hormone (AMH) levels are associated with cancer risk; and to investigate if age-related AMH trajectories differ between women who develop cancer and women who do not. More specifically, we examined associations with breast cancer, cancers in other tissues expressing AMH receptor AMHR2, and cancers in non-AMHR2-expressing tissues.

STUDY DESIGN

We included longitudinal data from 3025 women in the prospective Doetinchem Cohort Study. Cox proportional hazards models were used to assess the association of baseline age-specific AMH tertiles with cancer. We applied linear mixed models to compare age-related AMH trajectories between women who were diagnosed with cancer and women who were not.

MAIN OUTCOME MEASURES

Cancer (n = 385; 139 breast cancers, 112 cancers in other AMHR2-expressing tissues, 134 cancers in non-AMHR2-expressing tissues).

RESULTS

Overall, baseline age-specific AMH levels were not associated with cancer risk, although in women ≤ 40 years an increased risk was suggested for breast cancer (HR_T2:T1 = 2.06, 95%CI = 0.95-4.48; HR_T3:T1 = 2.03, 95%CI = 0.91-4.50). Analysis of age-related AMH trajectories suggested that AMH levels were higher at younger ages and declined faster in women who were diagnosed with cancer compared with women who were not, but our results did not provide evidence for actual differences in trajectories.

CONCLUSIONS

Our results did not provide evidence for an association between age-specific AMH levels and age-related trajectories and risk of cancer. However, effect estimates for breast cancer were in line with risk-increasing effects found in previous studies.

Anti-Müllerian Hormone Type II Receptor Expression in Endometrial Cancer Tissue

Anti-Müllerian hormone (AMH) is responsible for the Müllerian ducts' regression in male fetuses. In cells of cancers with AMH receptors (AMHRII), AMH induces cell cycle arrest or apoptosis. As AMH occurs naturally and does not exhibit significant side effects while reducing neoplastic cell colonies, it can be considered as a potential therapeutic agent for cancer treatment. The purpose of this study was to assess the AMHRII expression in endometrial cancer (EC) in correlation to various demographic data and clinical conditions. Immunohistochemical analysis was used to assess AMHRII expression in EC tissue samples retrieved from 230 women with pre-cancerous state of endometrium (PCS) and EC. AMHRII was detected in 100% of samples. No statistical difference was observed for AMHRII expression depending on the histopathological type of EC, cancer staging, body mass index, and age, as well as the number of years of menstruation, births and miscarriages, and average and total breastfeeding time. Diabetes mellitus type 2 is the only factor that has an impact on AMHRII expression in EC tissue. Thus, this study supports the idea of theoretical use of AMH in EC treatment because all histopathological types of EC at all stages of advancement present receptors for AMH.

SJI 2020 special issue: A catalogue of Ovarian Cancer targets for CAR therapy

Ovarian Cancer (OC) is currently difficult to cure, mainly due to its late detection and the advanced state of the disease at the time of diagnosis. Therefore, conventional treatments such as debulking surgery and combination chemotherapy are rarely able to control progression of the tumour, and relapses are frequent. Alternative therapies are currently being evaluated, including immunotherapy and advanced T cell-based therapy. In the present review, we will focus on a description of those Chimeric Antigen Receptors (CARs) that have been validated in the laboratory or are being tested in the clinic. Numerous target antigens have been defined due to the identification of OC biomarkers, and many are being used as CAR targets. We provide an exhaustive list of these constructs and their current status. Despite being innovative and efficient, the OC-specific CARs face a barrier to their clinical efficacy: the tumour microenvironment (TME). Indeed, effector cells expressing CARs have been shown to be severely inhibited, rendering the CAR T cells useless once at the tumour site. Herein, we give a thorough description of the highly immunosuppressive OC TME and present recent studies and innovations that have enabled CAR T cells to counteract this negative environment and to destroy tumours.

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.

Immunotherapy of ovarian cancer with a monoclonal antibody specific for the extracellular domain of anti-Müllerian hormone receptor II

Epithelial ovarian carcinoma (EOC) is the most prevalent and lethal form of ovarian cancer. The low five-year overall survival after EOC diagnosis indicates an urgent need for more effective ways to control this disease. Anti-Müllerian hormone receptor 2 (AMHR2) is an ovarian protein overexpressed in the majority of human EOCs. We have previously found that vaccination against the ovarian-specific extracellular domain of AMHR2 (AMHR2-ED) significantly inhibits growth of murine EOCs through an IgG-mediated mechanism that agonizes receptor signaling of a Bax/caspase-3 dependent proapoptotic cascade. To determine if a single monoclonal antibody (mAb) could inhibit growth of human EOC, we generated a panel of mAbs specific for recombinant human AMHR2-ED and characterized a candidate mAb for humanization and use in clinical trials. We found that our candidate 4D12G1 mAb is an IgG₁ that shows high affinity antigen-specific binding to the 7-mer ²⁰KTLGELL²⁶ sequence of AMHR2-ED that facilitates induction of programmed cell death in EOC cells. Most importantly, the 4D12G1 mAb significantly inhibits growth of primary human EOCs in patient-derived xenografts (PDXs) by inducing direct apoptosis of EOC tumors. Our results support the view that a humanized 4D12G1 mAb may be a much needed and effective reagent for passive immunotherapy of human EOC.

Purification of human recombinant anti-mullerian hormone and its derivatives

Anti-mullerian hormone (AMH) is a cytokine of transforming growth factor β (TGF-β) superfamily able to induce apoptosis in cells bearing specific AMH type II receptors (AMHRII). AMHRII is overexpressed in some malignant cells, so at present recombinant AMH (rAMH) is considered as a new candidate antineoplastic drug. The use of rAMH may be especially effective in case of such severe diseases as ovarian, prostate and breast cancer. However, the development of a new drug is hampered by the laboriousness of obtaining highly purified rAMH and by the lack of data about the pharmacological characteristics of rAMH derivatives. In this work, we obtained preparations of prohormone, half-cleaved rAMH and a C-terminal fragment of rAMH, which was confirmed by qualitative and quantitative analyses. To obtain rAMH and its derivatives we used a previously developed highly effective producer strain containing the optimized human AMH gene. The production process has been divided into several stages: (a) rAMH biosynthesis in the bioreactor; (b) culture media preparation; (c) purification of rAMH and its derivatives using immunoaffinity chromatography and reversed-phase HPLC; (d) identification of the purified proteins by immunoblotting and analytical reversed-phase HPLC; and (e) evaluation of the hormone forms activity. The obtained proteins may be used in preclinical trials and in vitro study of rAMH derivatives properties.

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.

CAR T Cells Targeting MISIIR for the Treatment of Ovarian Cancer and Other Gynecologic Malignancies

The prognosis of patients diagnosed with advanced ovarian or endometrial cancer remains poor, and effective therapeutic strategies are limited. The Müllerian inhibiting substance type 2 receptor (MISIIR) is a transforming growth factor β (TGF-β) receptor family member, overexpressed by most ovarian and endometrial cancers while absent in most normal tissues. Restricted tissue expression, coupled with an understanding that MISIIR ligation transmits apoptotic signals to cancer cells, makes MISIIR an attractive target for tumor-directed therapeutics. However, the development of clinical MISIIR-targeted agents has been challenging. Prompted by the responses achieved in patients with blood malignancies using chimeric antigen receptor (CAR) T cell therapy, we hypothesized that MISIIR targeting may be achieved using a CAR T cell approach. Herein, we describe the development and evaluation of a CAR that targets MISIIR. T cells expressing the MISIIR-specific CAR demonstrated antigen-specific reactivity in vitro and eliminated MISIIR-overexpressing tumors in vivo. MISIIR CAR T cells also recognized a panel of human ovarian and endometrial cancer cell lines, and they lysed a battery of patient-derived tumor specimens in vitro, without mediating cytotoxicity of a panel of normal primary human cells. In conclusion, these results indicate that MISIIR targeting for the treatment of ovarian cancer and other gynecologic malignancies is achievable using CAR technology.

[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 in Fertility Preservation: Clinical and Therapeutic Applications

Anti-Müllerian hormone (AMH) is a member of the transforming growth factor (TGF)-beta family and a key regulator of sexual differentiation and folliculogenesis. While the serum AMH level has been used in reproductive medicine as a biomarker of quantitative ovarian reserve for more than 20 years, new potential therapeutic applications of recombinant AMH are emerging, notably in the field of oncofertility. Indeed, it is well known that chemotherapy, used to treat cancer, induces ovarian follicular depletion and subsequent infertility. Animal models have been used widely to understand the effects of different cytotoxic agents on ovarian function, and several hypotheses regarding chemotherapy gonadotoxicity have been proposed, that is, it might have a direct detrimental effect on the primordial follicles constituting the ovarian reserve and/or on the pool of growing follicles secreting AMH. Recently, a new mechanism of chemotherapy-induced follicular depletion, called the “burn-out effect,” has been proposed. According to this theory, chemotherapeutic agents may lead to a massive growth of dormant follicles which are then destroyed. As AMH is one of the factors regulating the recruitment of primordial follicles from the ovarian reserve, recombinant AMH administration concomitant with chemotherapy might limit follicular depletion, therefore representing a promising option for preserving fertility in women suffering from cancer. This review reports on the potential usefulness of AMH measurement as well as AMH’s role as a therapeutic agent in the field of female fertility preservation.

Müllerian inhibiting substance/anti-Müllerian hormone type II receptor protein and mRNA expression in the healthy and cancerous endometria

Müllerian inhibiting substance/anti-Müllerian hormone (MIS/AMH) is a regulator of the female reproductive system, an indicator of ovarian reserve and a growth inhibitor of Müllerian duct-derived tumors in vivo and in vitro. The objective of the present study was to analyze MIS/AMH type II receptor (MIS/AMHRII) protein and mRNA expression in healthy human endometria compared with patients with endometrial hyperplasia and endometrial cancer, providing a foundation for MIS/AMH as a biological modifier for treatment of endometrial hyperplasia and endometrial cancer. The present study included healthy endometrial tissues (n=20), simple endometrial hyperplasia tissues without atypia (n=17), complex endometrial hyperplasia tissues without atypia (n=24) and endometrial cancer tissues (n=8). The location and variation of MIS/AMHRII protein expression was observed by immunohistochemistry. The expression was graded by two pathologists and was categorized as follows: Negative, weakly positive, moderately positive or strongly positive. Reverse transcription-quantitative polymerase chain reaction was used to quantify MIS/AMHRII mRNA expression. The expression of MIS/AMHRII protein was observed in the cytoplasm of healthy human endometria, endometrial hyperplasia and endometrial cancer cells. The frequency of MIS/AMHRII protein expression was 20.22±10.35% in the proliferative phase of the healthy endometrium and 24.09±11.73% in the secretory phase of the healthy endometrium. However, no differences were observed in the menstrual cycle phases. The frequency was 54.50±16.59% in endometrial hyperplasia without atypia, 55.10±15.87% in endometrial hyperplasia with atypia and 73.88±15.70% in endometrial cancer, indicating that expression was enhanced as the disease progressed from healthy to malignant status. In endometrial hyperplasia, MIS/AMHRII protein expression was significantly associated with histological complexity compared with atypia status. The present study demonstrated that MIS/AMHRII is present in healthy endometria, endometrial hyperplasia and endometrial cancer. The low expression frequency of MIS/AMHRII was not significantly different among normal endometrial tissues, however, the protein expression was elevated in endometrial hyperplasia and endometrial cancer. These findings indicated that the study of bioactive MIS/AMH, as a possible treatment for tumors expressing the MIS/AMH receptor, is essential.

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.

Anti-Müllerian hormone and risk of ovarian cancer in nine cohorts

Animal and experimental data suggest that anti-Müllerian hormone (AMH) serves as a marker of ovarian reserve and inhibits the growth of ovarian tumors. However, few epidemiologic studies have examined the association between AMH and ovarian cancer risk. We conducted a nested case-control study of 302 ovarian cancer cases and 336 matched controls from nine cohorts. Prediagnostic blood samples of premenopausal women were assayed for AMH using a picoAMH enzyme-linked immunosorbent assay. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariable-adjusted conditional logistic regression. AMH concentration was not associated with overall ovarian cancer risk. The multivariable-adjusted OR (95% CI), comparing the highest to the lowest quartile of AMH, was 0.99 (0.59-1.67) (Ptrend : 0.91). The association did not differ by age at blood draw or oral contraceptive use (all Pheterogeneity : ≥0.26). There also was no evidence for heterogeneity of risk for tumors defined by histologic developmental pathway, stage, and grade, and by age at diagnosis and time between blood draw and diagnosis (all Pheterogeneity : ≥0.39). In conclusion, this analysis of mostly late premenopausal women from nine cohorts does not support the hypothesized inverse association between prediagnostic circulating levels of AMH and risk of ovarian cancer.

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.

Potential therapeutic applications of human anti-Müllerian hormone (AMH) analogues in reproductive medicine

Members of the transforming growth factor-beta (TGF-beta) superfamily are key regulators of various physiological processes. Anti-Müllerian hormone (AMH) which is also commonly known as Müllerian-inhibiting substance (MIS) is a member of the TGF-beta superfamily and an important regulator of reproductive organ differentiation and ovarian follicular development. While AMH has been used for diagnostic purposes as a biomarker for over 15 years, new potential therapeutic applications of recombinant human AMH analogues are now emerging as pharmacologic agents in reproductive medicine. Therapeutic uses of AMH in gonadal tissue may provide a unique opportunity to address a broad range of reproductive themes, like contraception, ovulation induction, onset of menopause, and fertility preservation, as well as specific disease conditions, such as polycystic ovarian syndrome (PCOS) and cancers of the reproductive tract. This review explores the most promising therapeutic applications for a novel class of drugs known as AMH analogues with agonist and antagonist functions.

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.

Regulation of Murine Ovarian Epithelial Carcinoma by Vaccination against the Cytoplasmic Domain of Anti-Müllerian Hormone Receptor II

Anti-Müllerian hormone receptor, type II (AMHR2), is a differentiation protein expressed in 90% of primary epithelial ovarian carcinomas (EOCs), the most deadly gynecologic malignancy. We propose that AMHR2 may serve as a useful target for vaccination against EOC. To this end, we generated the recombinant 399-amino acid cytoplasmic domain of mouse AMHR2 (AMHR2-CD) and tested its efficacy as a vaccine target in inhibiting growth of the ID8 transplantable EOC cell line in C57BL/6 mice and in preventing growth of autochthonous EOCs that occur spontaneously in transgenic mice. We found that AMHR2-CD immunization of C57BL/6 females induced a prominent antigen-specific proinflammatory CD4+ T cell response that resulted in a mild transient autoimmune oophoritis that resolved rapidly with no detectable lingering adverse effects on ovarian function. AMHR2-CD vaccination significantly inhibited ID8 tumor growth when administered either prophylactically or therapeutically, and protection against EOC growth was passively transferred into naive recipients with AMHR2-CD-primed CD4+ T cells but not with primed B cells. In addition, prophylactic AMHR2-CD vaccination of TgMISIIR-TAg transgenic mice significantly inhibited growth of autochthonous EOCs and provided a 41.7% increase in mean overall survival. We conclude that AMHR2-CD vaccination provides effective immunotherapy of EOC with relatively benign autoimmune complications.

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.

Emerging and Evolving Ovarian Cancer Animal Models

Ovarian cancer (OC) is the leading cause of death from a gynecological malignancy in the United States. By the time a woman is diagnosed with OC, the tumor has usually metastasized. Mouse models that are used to recapitulate different aspects of human OC have been evolving for nearly 40 years. Xenograft studies in immunocompromised and immunocompetent mice have enhanced our knowledge of metastasis and immune cell involvement in cancer. Patient-derived xenografts (PDXs) can accurately reflect metastasis, response to therapy, and diverse genetics found in patients. Additionally, multiple genetically engineered mouse models have increased our understanding of possible tissues of origin for OC and what role individual mutations play in establishing ovarian tumors. Many of these models are used to test novel therapeutics. As no single model perfectly copies the human disease, we can use a variety of OC animal models in hypothesis testing that will lead to novel treatment options. The goal of this review is to provide an overview of the utility of different mouse models in the study of OC and their suitability for cancer research.

AAV9 delivering a modified human Mullerian inhibiting substance as a gene therapy in patient-derived xenografts of ovarian cancer

To improve ovarian cancer patient survival, effective treatments addressing chemoresistant recurrences are particularly needed. Mullerian inhibiting substance (MIS) has been shown to inhibit the growth of a stem-like population of ovarian cancer cells. We have recently engineered peptide modifications to human MIS [albumin leader Q425R MIS (LRMIS)] that increase production and potency in vitro and in vivo. To test this novel therapeutic peptide, serous malignant ascites from highly resistant recurrent ovarian cancer patients were isolated and amplified to create low-passage primary cell lines. Purified recombinant LRMIS protein successfully inhibited the growth of cancer spheroids in vitro in a panel of primary cell lines in four of six patients tested. Adeno-associated virus (AAV) -delivered gene therapy has undergone a clinical resurgence with a good safety profile and sustained gene expression. Therefore, AAV9 was used as a single i.p. injection to deliver LRMIS to test its efficacy in inhibiting growth of palpable tumors in patient-derived ovarian cancer xenografts from ascites (PDXa). AAV9-LRMIS monotherapy resulted in elevated and sustained blood concentrations of MIS, which significantly inhibited the growth of three of five lethal chemoresistant serous adenocarcinoma PDXa models without signs of measurable or overt toxicity. Finally, we tested the frequency of MIS type II receptor expression in a tissue microarray of serous ovarian tumors by immunohistochemistry and found that 88% of patients bear tumors that express the receptor. Taken together, these preclinical data suggest that AAV9-LRMIS provides a potentially well-tolerated and effective treatment strategy poised for testing in patients with chemoresistant serous ovarian cancer.

Transcriptome analysis reveals that Müllerian inhibiting substance regulates signaling pathways that contribute to endometrial carcinogenesis

Müllerian inhibiting substance (MIS) has been shown to inhibit growth of a number of tumors in vitro and/or in vivo, but the downstream pathways which it regulates are not fully understood. In the present study we show that MIS type II receptor was highly expressed in AN3CA cells, a cell line derived from human endometrial cancer cell in which MIS-treatment caused a reduction of cell viability, and induced cellular apoptosis and genes involved cell cycle arrest. To understand the genome-wide effects of MIS on gene regulation, we performed serial gene expression analyses from 0 to 96 h at 24 h intervals after treating AN3CA cells with MIS. Transcriptomic analysis of molecular changes induced by MIS identified 2,688 differentially expressed genes that were significantly up- or down-regulated during the 96 h study period. When the 2,688 differentially expressed genes were mapped to known biological processes, Wnt-, cancer-, proteolysis-, cytoskeleton-, cell cycle-, apoptosis-, and MAPK-signaling pathways emerged as the functions most significantly changed by MIS in AN3CA cells. Furthermore, western blot analysis validated that protein expression of cell cycle inhibitory genes, apoptotic protease activating factor-1 (APAF-1), β-catenin-interacting protein (ICAT), Rb related protein 130 (p130), and inhibitor of disheveled Dvl and Axin complex (IDAX), were gradually increased over the time of the study, whereas downstream cell cycle activating genes, cyclin-dependent kinase 2 (CDK2) and phospho-c-Jun were downregulated in MIS-treated AN3CA cells. These transcriptome analyses support previous observations that MIS functions as a tumor suppressor, potentially by regulating signaling pathways that could contribute to endometrial carcinogenesis, and indicating that MIS should be considered as a potential treatment for endometrial cancer.

Müllerian inhibiting substance/anti-Müllerian hormone: A novel treatment for gynecologic tumors

Müllerian inhibiting substance (MIS), also called anti-Müllerian hormone (AMH), is a member of the transforming growth factor-β super-family of growth and differentiation response modifiers. It is produced in immature Sertoli cells in male embryos and binds to MIS/AMH receptors in primordial Müllerian ducts to cause regression of female reproductive structures that are the precursors to the fallopian tubes, the surface epithelium of the ovaries, the uterus, the cervix, and the upper third of the vagina. Because most gynecologic tumors originate from Müllerian duct-derived tissues, and since MIS/AMH causes regression of the Müllerian duct in male embryos, it is expected to inhibit the growth of gynecologic tumors. Purified recombinant human MIS/AMH causes growth inhibition of epithelial ovarian cancer cells and cell lines in vitro and in vitro via MIS receptor-mediated mechanism. Furthermore, several lines of evidence suggest that MIS/AMH inhibits proliferation in tissues and cell lines of other MIS/AMH receptor-expressing gynecologic tumors such as cervical, endometrial, breast, and in endometriosis as well. These findings indicate that bioactive MIS/AMH recombinant protein should be tested in patients against tumors expressing the MIS/AMH receptor complex, perhaps beginning with ovarian cancer because it has the worst prognosis. The molecular tools to identify MIS/AMH receptor expressing ovarian and other cancers are in place, thus, it is possible to select patients for treatment. An MIS/AMH ELISA exists to follow administered doses of MIS/AMH, as well. Clinical trials await the production of sufficient supplies of qualified recombinant human MIS/AMH for this purpose.

Anti-Müllerian hormone is associated with extrauterine involvement and stage of disease in patients with endometrial cancer

Our aim was to evaluate serum levels of anti-Müllerian hormone (AMH) and also immunohistochemical (IHC) staining properties of AMH receptor type II (AMHRII) in patients with endometrial cancer (EC) and a control group. Preoperatively, serum levels of AMH were assessed and AMHRII expression was evaluated by immunohistochemistry in a benign and malignant group. AMH serum levels of the control group and EC patients were comparable. For EC patients, there was no difference with respect to the AMH levels and tumour stage; grade; histological type; deep myometrial invasion; lymphovascular space invasion or lymph node involvement. However, AMH levels in patients with extrauterine involvement were higher than patients with disease confined to the uterus. EC samples were more likely to be stained positive for AMHRII than benign lesions. Also, as the stage of the lesion worsens, the rate of IHC staining of AMHRII decreases. In conclusion, AMHRII is expressed in normal endometrial cells as well as endometrial cancer cells. AMH levels increase in EC, with extrauterine involvement at least in locally advanced disease. Also AMH expression decreases as the disease is staged-up.

Anti-mullerian hormone is expressed by endometriosis tissues and induces cell cycle arrest and apoptosis in endometriosis cells

Background

The anti-mullerian hormone (AMH) is a member of the transforming growth factor β (TGF-β) superfamily, which is responsible of the regression of the mullerian duct. AMH is expressed in the normal endometrium, where, acting in a paracrine fashion, negatively regulates cellular viability. Our objective was to evaluate the in vitro effects of the treatment with AMH of endometriosic cells.

Methods

AMH expression in human endometriosis glands was evaluated by immunohistochemistry. RT-PCR has been used to quantify the expression levels of AMH and AMH RII isoforms, as well as of cytochrome P450 in both endometriosis epithelial and stromal cells Effects of AMH and AMH-cleaved treatment in endometriosis cells were evaluated by flow-cytometry analysis. Finally, it has been evaluated the effect of plasmin-digested AMH on cytochrome P450 activity.

Results

AMH and AMH RII isoforms, as well as cytochrome P450, were expressed in both endometriosis epithelial and stromal cells. Treatment of endometriosis stromal and epithelial cell growth with AMH was able to induce a decrease in the percentage of cells in S phase and increase percentage of cells in G1 and G2 phase; coherently, decreased cell viability and increased percentage of cells death fraction was observed. The plasmin-digested AMH was able to suppress most of the cytochrome P450 activity, causing an increase of pre-G1 phase and of apoptosis induction treating with plasmin-digested AMH in both cell lines, most marked in the epithelial cells.

Conclusions

The data produced suggest a possible use of AMH as therapeutic agents in endometriosis.

Anti-Mullerian hormone and risk of invasive serous ovarian cancer

PURPOSE

Epithelial ovarian cancers either arise directly from Mullerian-type epithelium or acquire Mullerian characteristics in the course of neoplastic transformation. The anti-Mullerian hormone (AMH) causes regression of Mullerian structures during fetal development in males and has been shown to inhibit the growth of epithelial ovarian cancer. Therefore, we hypothesized that pre-diagnostic serum concentrations of AMH are inversely associated with risk of invasive serous ovarian cancer.

METHODS

A case-control study (107 cases, 208 controls) was nested within the population-based Finnish Maternity Cohort (1986-2007). The sample donated during the first trimester of the last pregnancy preceding cancer diagnosis of the case subjects was selected for the study. For each case, two controls, matched on age and date at sampling, as well as parity at sampling and at cancer diagnosis were selected. AMH was measured by a second-generation AMH ELISA. Conditional logistic regression was used to compute odds ratios (OR) and 95 % confidence intervals (CI) for invasive serous ovarian cancer associated with AMH concentrations.

RESULTS

Overall AMH concentrations were not associated with risk of invasive serous ovarian cancer (OR 0.93; 95 % CI 0.49-1.77 for top vs. bottom tertile, P trend=0.83). In women older than the median age at sampling (32.7 years), a doubling of AMH was associated with decreased risk (OR 0.69; 95 % CI 0.49-0.96), whereas an increased risk (OR 1.64; 95 % CI 1.06-2.54) was observed in younger women, P homogeneity = 0.002.

CONCLUSIONS

In this first prospective investigation, risk of invasive serous ovarian cancer was not associated with pre-diagnostic AMH concentrations overall; however, the association may depend on age at AMH measurement.

Control of spontaneous ovarian tumors by CD8+ T cells through NKG2D-targeted delivery of antigenic peptide

Background

There is an urgent need to develop targeted therapies for the control of advanced stage ovarian cancer because it is the most deadly gynecologic cancer. Antigen-specific immunotherapy is a promising approach because of the potential of the immune system to specifically target tumors without the toxicity associated with traditional chemoradiation. However, one of the major limitations for antigen-specific cancer immunotherapy is the pre-existing immune tolerance against endogenous targeted tumor antigens that frequently evolves during carcinogenesis. Here, we described the creation of a therapeutic agent comprised of a tumor-homing module fused to a functional domain capable of selectively rendering tumor cells sensitive to foreign antigen-specific CD8+ T cell-mediated immune attack, thereby circumventing many aspects of immune tolerance. The tumor-homing module, NKG2D, specifically binds to NKG2D ligand that is commonly overexpressed in ovarian tumors. The functional domain is comprised of the Fc portion of IgG2a protein and foreign immunogenic CD8⁺ T cell epitope flanked by furin cleavage sites (R), which can be recognized and cleaved by furin that is highly expressed in the tumor microenvironment.

Results

We show that this therapeutic chimeric protein specifically loaded antigenic epitope onto the surface of NKG2D ligand-expressing ovarian tumor cells, rendering ovarian tumors susceptible to antigen-specific CTL-mediated killing in vitro. Furthermore, we show that intraperitoneal administration of our therapeutic chimeric protein followed by adoptive transfer of antigen-specific CD8+ T cells generates potent antitumor effects and significant accumulation of antigen-specific CD8+ T cells in the tumor loci.

Conclusions

Our findings have promise for bypassing immune tolerance to enhance cancer immunotherapy.

Mullerian inhibiting substance suppresses proliferation and induces apoptosis and autophagy in endometriosis cells in vitro

Objective. To determine the effects of Mullerian inhibiting substance (MIS) treatment on endometriosis cells through study of apoptosis and autophagy. Design. Experimental in vitro study. Setting. University research laboratory. Cell Line. CRL-7566 endometriosis cell line. This line was established from a benign ovarian cyst taken from a patient with endometriosis. Interventions. In vitro treatment with MIS. Main Outcome Measures. The main outcome measures were cellular viability, proliferation, cell-cycle arrest, and induction of apoptosis and autophagy in endometriotic cells. Results. MIS treatment inhibited proliferation of endometriosis cells and induced apoptosis, as indicated by Annexin V staining, and induced caspase-9 cleavage and cell-cycle arrest, as evidenced by increased expression of p27 CDK-inhibitor. MIS treatment also induced autophagy in endometriosis cells as demonstrated by a significant increase in LC3-II induction, a hallmark of autophagy. Conclusions. MIS inhibits cell growth and induces autophagy, as well as apoptosis, in ectopic endometrial cell lines. Our results suggest that MIS may have a potential as a novel approach for medical treatment of endometriosis. Further studies may be needed to test the efficacy of MIS treatment in animal models and to develop MIS treatment specifically targeted to the endometriosis.

The Müllerian inhibiting substance type 2 receptor suppresses tumorigenesis in testes with sustained β-catenin signaling

Dysregulated WNT/β-catenin signaling in murine testes results in a phenotype with complete germ cell loss that resembles human Sertoli cell-only syndrome. In other systems, including the ovary, dysregulated WNT/β-catenin induces tumorigenesis but no tumors are observed in the mutant testes without deletion of a tumor suppressor, such as phosphatase and tensin homolog (PTEN). Müllerian inhibiting substance (MIS, also known as AMH), a member of the transforming growth factor-β family of growth factors responsible for Müllerian duct regression in fetal males, has been shown to inhibit tumor growth in vitro and in vivo but its role as an endogenous tumor suppressor has never been reported. We have deleted the MIS type 2 receptor (MISR2), and thus MIS signaling, in mice with dysregulated WNT/β-catenin and show that these mice develop testicular stromal tumors with 100% penetrance within a few months postnatal. The tumors are highly proliferative and have characteristics of either Sertoli cell tumors or progenitor Leydig cell tumors based on their marker profiles and histology. Phosphorylated Sma and mothers against decapentaplegic-related homolog 1/5/8 is absent in the tumors and β-catenin target genes are induced. The tumor suppressor TP53 is also highly expressed in the tumors, as is phosphorylated γH2AX, which is indicative of DNA damage. The phenotype of these tumors closely resembles those observed when PTEN is also deleted in mice with dysregulated WNT/β-catenin. Tumorigenesis in these mice provides conclusive evidence that physiological MIS signaling is a tumor suppressor mechanism and suggests that targeted treatment of MISR2-expressing cancers with therapeutic MIS should have a beneficial effect on tumor progression.

Tumor-targeted delivery of IL-2 by NKG2D leads to accumulation of antigen-specific CD8+ T cells in the tumor loci and enhanced anti-tumor effects

Interleukin-2 (IL-2) has been shown to promote tumor-specific T-cell proliferation and differentiation but systemic administration of IL-2 results in significant toxicity. Therefore, a strategy that can specifically deliver IL-2 to the tumor location may alleviate concerns of toxicity. Because NKG2D ligands have been shown to be highly expressed in many cancer cells but not in healthy cells, we reason that a chimeric protein consisting of NKG2D linked to IL-2 will lead to the specific targeting of IL-2 to the tumor location. Therefore, we created chimeric proteins consisting of NKG2D linked to Gaussia luciferase (GLuc; a marker protein) or IL-2 to form NKG2D-Fc-GLuc and NKG2D-Fc-IL2, respectively. We demonstrated that NKG2D linked to GLuc was able to deliver GLuc to the tumor location in vivo. Furthermore, we showed that TC-1 tumor-bearing mice intramuscularly injected with DNA encoding NKG2D-Fc-IL2, followed by electroporation, exhibited an increased number of luciferase-expressing E7-specific CD8+ T cells at the tumor location. More importantly, treatment with the DNA construct encoding NKG2D-Fc-IL2 significantly enhanced the therapeutic anti-tumor effects generated by intradermal vaccination with therapeutic HPV DNA in tumor-bearing mice. Therefore, by linking NKG2D to IL2, we are able to specifically deliver IL-2 to the tumor location, enhancing antigen-specific T-cell immune response and controlling tumor growth. Our approach represents a platform technology to specifically deliver proteins of interest to tumor loci.

Expression of Müllerian inhibiting substance type II receptor and antiproliferative effects of MIS on human cervical cancer

This study aimed to analyze expression of Müllerian inhibiting substance type II receptor (MISRII) protein and mRNA in cervical neoplasia, to demonstrate the growth inhibition of cervical cancer cells by administration of highly purified recombinant human Müllerian inhibiting substance (MIS) and, furthermore, to evaluate the clinical significance of MIS as a biological modifier for MIS receptor expressing tumors. Reverse transcriptase polymerase chain reaction (RT-PCR) was used for MISRII mRNA expression, and in situ hybridization and immunohistochemistry were used to observe expression, location of MISRII mRNA and protein, respectively. To demonstrate the effect of MIS on the viability of cervical cancer cells, methyl thiazole tetrazolium (MTT) assay was performed. Flow cytometry was used to evaluate the cell cycle distribution after exposure to MIS in cervical cancer cells, and the annexin-V-FITC staining method was performed to demonstrate apoptosis by MIS in cervical cancer cells. Expression of MISRII protein and mRNA were observed in all normal cervical and cervical carcinoma tissues. There was no significant difference in expression of MISRII protein and MISRII mRNA between normal cervical and cervical carcinoma tissues. MTT assay showed negative correlation between MIS exposure time and the viability of cervical cells (P=0.008). The changes in cell cycle distribution after MIS exposure suggest that MIS plays an important role in inducing cellular apoptosis by causing arrest at the G1 phase and increasing cells at sub-G0G1 phase. Annexin-V-FITC staining methods showed that cellular apoptosis was, respectively, 10.44 and 12.89% after 24 and 48 h of MIS exposure in cervical carcinoma cells. There was a negative correlation between cellular survival and MIS exposure time. This study demonstrates that MISRII is present on normal cervical and cervical carcinoma tissues, and MIS shows receptor-mediated antiproliferative effect on cervical cells in vitro. These data suggest that MIS may be used as a biological modifier or therapeutic modulator on MISRII-expressing tumors in the future.