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.

Mullerian inhibiting substance induces apoptosis of human endometrial stromal cells in endometriosis

CONTEXT

Müllerian inhibiting substance (MIS) is produced in Sertoli cells of fetal testis and causes regression of müllerian ducts in male embryos. MIS also can induce the cell cycle arrest and apoptosis in müllerian duct-derived tumors in vivo and in vitro.

OBJECTIVE

Our objective was to investigate the expression of MIS type II receptor (MISR II) and whether MIS can inhibit the proliferation and induce apoptosis in primary cultures of endometrial stromal cells (ESC) of endometriosis.

DESIGN AND SETTINGS

In vitro experiments were performed in the university research laboratory.

PARTICIPANTS

Tissue samples from 12 patients who had undergone evisceration for ovarian endometrial cysts were included in this study.

INTERVENTIONS AND MAIN OUTCOME MEASURES

The expression of MISR II in ESC was investigated by immunohistochemistry. The cell viability and apoptosis in ESC treated with MIS was measured by methylthiazoletetrazolium assay and annexin V analysis. The expression of regulatory proteins in ESC treated with MIS was shown by Western blotting.

RESULTS

ESC showed specific immunostaining for the MISR II. ESC treated with MIS exhibited 32% growth inhibition (P = 0.0001). The changes in cell cycle distribution after MIS exposure at 72 h demonstrated that S and G(2)M phases were decreased; G(0)G(1) and sub-G(0)G(1) phases were increased. ESC treated with MIS showed 13.72% annexin V-fluorescein isothiocyanate positivity. In the ESCs, which contain defective p16, MIS increased the expression of pocket proteins p107 and p130 and decreased E2F transcription factor 1.

CONCLUSIONS

The results support a central role for MIS in endometriosis. Although the precise mechanism of MIS-mediated inhibition of ESC growth has not been fully defined, these data suggest that MIS has activity against ESC in vitro and may also be an effective targeted therapy for endometriosis.

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.

Müllerian inhibiting substance is anterogradely transported and does not attenuate avulsion-induced death of hypoglossal motor neurons

Müllerian Inhibiting Substance (MIS, Anti-Müllerian hormone) is a gonadal hormone that contributes to the subtle sex-biases in the nervous system. Mature neurons of both sexes also produce MIS, suggesting that MIS may be a paracrine regulator of adult neural networks. We report here that murine hypoglossal motor neurons produce MIS and its receptors, MISRII and bone morphogenetic protein receptor 1A (BMPR1A, ALK3), but differentially transport them, with only MIS being detectable in axons. The production of MIS and its receptors were rapidly down regulated after axonal damage, which is a characteristic of genes involved in mature neuronal function. MIS is a survival factor for embryonic spinal motor neurons, but the rate of cell loss after hypoglossal nerve avulsion was normal in Mis(-/-) mice and was not attenuated by intraventricular administration of MIS. These observations suggest that MIS may be involved in anterograde rather than autocrine or retrograde regulation of neurons.

Mullerian inhibiting substance inhibits invasion and migration of epithelial cancer cell lines

OBJECTIVE

Given the fact that Mullerian Inhibiting Substance (MIS) causes complex remodeling of the urogenital ridge and regression of the Mullerian ducts during male embryonic development, we examined whether MIS could affect similar cell properties such as migration and invasion that could contribute ultimately to micro-metastasis of cancers arising from Mullerian tissues. MIS receptor expressing cell lines found to be invasive and migratory in vivo are examined in an in vivo assay that is cost-effective.

METHODS

We designed in vitro and in vivo experiments to determine if MIS inhibited the movement of cancer lines IGROV-1, HEp3, MDA-MB-231, and HT1080 in cell culture invasion/migration chamber assays and in chick embryo metastasis assays.

RESULTS

MIS, at concentrations below those that inhibit cell proliferation, blocked in vitro invasion and in vivo migration of epithelial cancer cells that express the MIS receptor.

CONCLUSIONS

While our laboratory has previously established MIS as an inhibitor of cancer cell proliferation using in vitro assays and in vivo xenografts, we now show that MIS can also inhibit in vivo tumor migration.

Müllerian inhibiting substance/anti-Müllerian hormone: a potential therapeutic agent for human ovarian and other cancers

According to the 2008 American Cancer Society statistics, cancer remains the second leading cause of death in American today. Early detection, innovative surgery, new drugs and increased public education regarding avoidable risk factors, such as smoking, have had significant impact on the incidence and survival rates of many cancers, while overall death rates from all cancers have declined a modest 5% over the past 50 years. Ovarian cancer statistics, however, have not been as encouraging. Despite recent advances in the management of this disease, 5-year survival has not improved, and the search continues for rationally designed new treatments. Müllerian Inhibiting Substance is a strong candidate because it addresses many of the deficiencies of existing treatments. Namely, Müllerian Inhibiting Substance has little demonstrated toxicity, it complements the activity of known anticancer drugs, it is highly specific against cancers expressing its receptor and it inhibits the proliferation of drug-resistant tumors.

Development of an efficiently cleaved, bioactive, highly pure FLAG-tagged recombinant human Mullerian Inhibiting Substance

Mullerian Inhibiting Substance (MIS), a member of the TGF-beta family, causes regression of the Mullerian duct in male embryos, after binding to Mullerian Inhibiting Substance Receptor II (MISRII). It has also been extensively demonstrated that it can inhibit proliferation of various cancer cell lines such as ovarian, prostate, and breast cancer in vitro and in vivo. Hence, the availability of a recombinant, epitope tagged, bioactive MIS is important for the selection of patients for treatment and for probing novel molecular targets for MIS in various tissues. To this end, we have expressed a recombinant, internally FLAG-tagged form of hMIS with the tag (DYKDDDDK) immediately after the cleavage site (427-428) of MIS at the C-terminus with a modified dibasic cleavage motif sequence. We show that this construct results in a highly pure, endogenously processed (cleaved) FLAG MIS, that causes complete regression of the Mullerian Duct in an organ culture assay. In addition, purified FLAG MIS was able to bind and affinity purify both transfected and endogenous MIS type II receptor. The availability of this fully functional, epitope tagged form of MIS should facilitate scale-up for preclinical and clinical use and should also be used for the study of MIS binding proteins and for tracking in pharmacokinetic studies.

The expression of Müllerian inhibiting substance/anti-Müllerian hormone type II receptor protein and mRNA in benign, borderline and malignant ovarian neoplasia

This study investigated the expression patterns of Müllerian inhibiting substance/anti-Müllerian hormone type II receptor (MIS/AMHRII) and mRNA in various types of ovarian neoplasia and evaluated the clinical significance of MIS/AMH as a biological response modifier for MIS/AMHR-positive tumors. Reverse transcriptase polymerase chain reaction was used to detect MIS/AMHRII mRNA expression and in situ hybridization and immunohistochemistry were used to localize MIS/AMHRII mRNA and protein expression. The degree of expression was scored from 0 (no staining) to 3 (strong staining). There was no significant difference in expression intensity between MIS/AMHRII protein and mRNA on all ovarian samples whether benign or malignant. MIS/AMHRII protein and mRNA were weakly expressed on 45.45% of benign ovarian tumors. In borderline tumors, expression rates of MIS/AMHRII protein and mRNA were 77.78% with score 1.22 and 55.56% with score 1, respectively. In malignant ovarian tumors, expression rates of MIS/AMHRII protein and mRNA were 70% with score 1.23 and 75% with score 1.43, respectively. Among malignant ovarian tumors, sex cord stromal tumors showed the highest expression rate and the strongest intensity of MIS/AMHRII protein and mRNA followed by germ cell tumor and epithelial ovarian tumor. Non-epithelial malignant tumors showed stronger expression than that of epithelial tumors (P<0.05, P<0.001, respectively). In serous borderline malignant and malignant tumors, MIS/AMHRII protein and mRNA expression was 63.64 and 81.82% with expression intensity of 1.27 and 1.46, respectively, which were not statistically different from non-epithelial malignant tumors. MIS/AMHRII and MIS/AMHRII mRNA demonstrate significantly variable expression among different ovarian tumor types. Non-epithelial cell tumors show higher expression than those of epithelial cell tumors. The highest expression rate and intensity were observed on sex cord stromal tumors. MIS/AMHRII expression was not different according to the differentiation, but showed tissue-type specificity. These data support that MIS/AMH may be used as a biological modifier or therapeutic modulator in MIS/AMHRII-expressed ovarian tumors.

Cell migration and activated PI3K/AKT-directed elongation in the developing rat Müllerian duct

In vertebrates, the Müllerian duct elongates along the Wolffian duct, a mesonephric structure that is required for Müllerian duct formation. Recently, several genes required for initial Müllerian duct formation have been identified. However, the precise mechanism of Müllerian duct elongation remains to be elucidated. In this study, we investigated dynamic morphological changes in the elongating Müllerian duct in rat urogenital ridges in organ culture manipulated by microincision and/or chemical inhibitors. Mechanical division of the developing Müllerian duct showed that epithelial cells of the Müllerian duct actively migrate along the anterior-posterior axis independent of the proliferative expansion of the anterior portion of the duct. We found that the PI3K/AKT signaling pathway is activated in the Müllerian duct epithelium and is required for elongation of the tip of the duct; however, migration of Müllerian duct epithelial cells proximal to the tip remains intact when PI3K/AKT is inactivated. Although much is known about the molecular and cellular mechanisms leading to Müllerian duct regression, the present findings provide a fuller understanding of the mechanisms contributing to Müllerian duct formation and to the general process of early tubulogenesis.

Expression of anti-Müllerian hormone (AMH) in equine granulosa-cell tumors and in normal equine ovaries

Anti-Müllerian hormone (AMH), also known as Müllerian inhibiting substance (MIS), is expressed by granulosa cells in females of many mammalian species, and circulating AMH concentrations have been used to monitor granulosa-cell tumors (GCT) in women. The objective was to characterize expression of AMH in equine GCT, and in normal equine ovaries, based upon immunohistochemistry (IHC), using a polyclonal primary antibody directed against human AMH. Equine GCT (n=27) and normal equine ovaries (n=10) were examined by IHC. In addition, sera from four mares with GCT were characterized for AMH bioactivity, based upon suppression of Müllerian duct development in the fetal rat. Immunolabeling with alpha-AMH was localized to granulosa cells in equine GCT, as well as within antral follicles in normal ovaries. Expression of AMH first appeared in granulosa cells of small growing follicles and was most intense in small antral follicles; large antral or atretic follicles had reduced immunolabeling. Omission of the primary antibody or incubation of the primary antibody with the corresponding blocking peptide eliminated immunolabeling of granulosa cells in GCT and in normal antral follicles, confirming the specificity of the immunolabel. Sera from mares with GCT had increased AMH bioactivity compared to control sera. In conclusion, AMH was strongly expressed by granulosa cells in equine GCT and in normal antral follicles. Therefore, anti-Müllerian hormone may be a useful biomarker for detection of GCT in the horse.

Mutations in LRP2, which encodes the multiligand receptor megalin, cause Donnai-Barrow and facio-oculo-acoustico-renal syndromes

Donnai-Barrow syndrome is associated with agenesis of the corpus callosum, congenital diaphragmatic hernia, facial dysmorphology, ocular anomalies, sensorineural hearing loss and developmental delay. By studying multiplex families, we mapped this disorder to chromosome 2q23.3-31.1 and identified LRP2 mutations in six families with Donnai-Barrow syndrome and one family with facio-oculo-acoustico-renal syndrome. LRP2 encodes megalin, a multiligand uptake receptor that regulates levels of diverse circulating compounds. This work implicates a pathway with potential pharmacological therapeutic targets.

Mullerian-inhibiting substance induces Gro-beta expression in breast cancer cells through a nuclear factor-kappaB-dependent and Smad1-dependent mechanism

Mullerian-inhibiting substance (MIS), a transforming growth factor-beta family member, activates the nuclear factor-kappaB (NF-kappaB) pathway and induces the expression of B-cell translocation gene 2 (BTG2), IFN regulatory factor-1 (IRF-1), and the chemokine Gro-beta. Inhibiting NF-kappaB activation with a phosphorylation-deficient IkappaBalpha mutant abrogated MIS-mediated induction of all three genes. Expression of dominant-negative Smad1, in which serines at the COOH-terminal SSVS motif are converted to alanines, suppressed MIS-induced Smad1 phosphorylation and impaired MIS-stimulated Gro-beta promoter-driven reporter expression and Gro-beta mRNA. Suppressing Smad1 expression using small interfering RNA also mitigated MIS-induced Gro-beta mRNA, suggesting that regulation of Gro-beta expression by MIS was dependent on activation of NF-kappaB as well as Smad1. However, induction of IRF-1 and BTG2 mRNAs by MIS was independent of Smad1 activation. Characterization of kappaB-binding sequences within Gro-beta, BTG2, and IRF-1 promoters showed that MIS stimulated binding of p50 and p65 subunits to all three sites, whereas phosphorylated Smad1 (phospho-Smad1) protein was detectable only in the NF-kappaB complex bound to the kappaB site of the Gro-beta promoter. Consistent with these observations, chromatin immunoprecipitation assays showed recruitment of both phospho-Smad1 and p65 to the Gro-beta promoter in vivo, whereas p65, but not phospho-Smad1, was recruited to the BTG2 promoter. These results show a novel interaction between MIS-stimulated Smad1 and NF-kappaB signaling in which enhancement of NF-kappaB DNA binding and gene expression by phospho-Smad1 is dependent on the sequence of the kappaB consensus site within the promoter.

Serum müllerian-inhibiting substance in Down's syndrome pregnancies

BACKGROUND

To examine whether maternal serum levels of müllerian-inhibiting substance (MIS) differ in Down's syndrome and unaffected pregnancies.

METHODS

Case-control study was conducted using stored serum from an antenatal screening programme. Sera from 25 Down's syndrome pregnancies were retrieved from -20 degrees C storage together with 125 unaffected controls individually matched for maternal age, weeks of gestation and duration of storage. Results were expressed in multiples of the gestation-specific median value (MoM) in controls.

RESULTS

The median value in Down's syndrome pregnancies was 0.83 MoM (P = 0.77, two-tail Wilcoxon rank sum test). Among unaffected pregnancies, there was a statistically significant correlation between MIS and pregnancy-associated plasma protein-A (P < 0.05). MIS levels were elevated in pregnancies where assisted reproduction techniques had been used.

CONCLUSION

There is no evidence for a substantial reduction in maternal serum MIS levels in Down's syndrome pregnancies. This study provides useful information regarding serum MIS levels in pregnancy.

Mullerian Inhibiting Substance enhances subclinical doses of chemotherapeutic agents to inhibit human and mouse ovarian cancer

Mullerian Inhibiting Substance (MIS), a biological modifier that causes regression of Mullerian ducts in male embryos, is effective as a single agent in vitro and in vivo against human and mouse ovarian cancer cell lines expressing MIS type II receptor; however, little is known about how recombinant human MIS (rhMIS), now being scaled for preclinical trials, could be used in combination with cytotoxic or targeted chemotherapeutic agents. Mouse serous and endometrioid ovarian carcinoma cell lines were tested in vitro against rhMIS alone and with doxorubicin, paclitaxel, or cisplatin as agents in clinical use. Because MIS releases FK506 binding protein (FKBP12), which activates the mammalian target of rapamycin (mTOR) downstream of Akt, rhMIS and rapamycin combinations were tested. MIS increases p16 protein levels, and 5'-Aza-2'-deoxycytidine (AzadC) induces p16 mRNA; therefore, they were used in combination in vitro and in vivo with a human ovarian cancer cell line. A paclitaxel-resistant human ovarian cancer cell line and its parental line both respond to rhMIS in vitro. Additivity, synergy, or competition was observed with MIS and rapamycin, AzadC, doxorubicin, cisplatin, and paclitaxel, suggesting that MIS in combination with selective targeted therapies might achieve greater activity against ovarian cancer than the use of each individual agent alone. These assays and statistical analyses could be useful in selecting rhMIS and chemotherapeutic agent combinations that enhance clinical efficacy and reduce toxicity.

Ovarian cancer side population defines cells with stem cell-like characteristics and Mullerian Inhibiting Substance responsiveness

The recent identification of "side population" (SP) cells in a number of unrelated human cancers and their normal tissue sources has renewed interest in the hypothesis that cancers may arise from somatic stem/progenitor cells. The high incidence of recurrence attributable to multidrug resistance and the multiple histologic phenotypes indicative of multipotency suggests a stem cell-like etiology of ovarian cancer. Here we identify and characterize SP cells from two distinct genetically engineered mouse ovarian cancer cell lines. Differential efflux of the DNA-binding dye Hoechst 33342 from these cell lines defined a human breast cancer-resistance protein 1-expressing, verapamil-sensitive SP of candidate cancer stem cells. In vivo, mouse SP cells formed measurable tumors sooner than non-SP (NSP) cells when equal numbers were injected into the dorsal fat pad of nude mice. The presence of Mullerian Inhibiting Substance (MIS) signaling pathway transduction molecules in both SP and NSP mouse cells led us to investigate the efficacy of MIS against these populations in comparison with traditional chemotherapies. MIS inhibited the proliferation of both SP and NSP cells, whereas the lipophilic chemotherapeutic agent doxorubicin more significantly inhibited the NSP cells. Finally, we identified breast cancer-resistance protein 1-expressing verapamil-sensitive SPs in three of four human ovarian cancer cell lines and four of six patient primary ascites cells. In the future, individualized therapy must incorporate analysis of the stem cell-like subpopulation of ovarian cancer cells when designing therapeutic strategies for ovarian cancer patients.

Müllerian inhibiting substance regulates its receptor/SMAD signaling and causes mesenchymal transition of the coelomic epithelial cells early in Müllerian duct regression

Examination of Müllerian inhibiting substance (MIS) signaling in the rat in vivo and in vitro revealed novel developmental stage- and tissue-specific events that contributed to a window of MIS responsiveness in Müllerian duct regression. The MIS type II receptor (MISRII)-expressing cells are initially present in the coelomic epithelium of both male and female urogenital ridges, and then migrate into the mesenchyme surrounding the male Müllerian duct under the influence of MIS. Expression of the genes encoding MIS type I receptors, Alk2 and Alk3, is also spatiotemporally controlled; Alk2 expression appears earlier and increases predominantly in the coelomic epithelium, whereas Alk3expression appears later and is restricted to the mesenchyme, suggesting sequential roles in Müllerian duct regression. MIS induces expression of Alk2, Alk3 and Smad8, but downregulates Smad5 in the urogenital ridge. Alk2-specific small interfering RNA (siRNA) blocks both the transition of MISRII expression from the coelomic epithelium to the mesenchyme and Müllerian duct regression in organ culture. Müllerian duct regression can also be inhibited or accelerated by siRNA targeting Smad8 and Smad5,respectively. Thus, the early action of MIS is to initiate an epithelial-to-mesenchymal transition of MISRII-expressing cells and to specify the components of the receptor/SMAD signaling pathway by differentially regulating their expression.

Recombinant human Mullerian inhibiting substance inhibits long-term growth of MIS type II receptor-directed transgenic mouse ovarian cancers in vivo

PURPOSE

Mullerian inhibiting substance (MIS) is a glycoprotein hormone that causes Mullerian duct regression in male embryos. In short-term experiments, recombinant human MIS (rhMIS) inhibits xenotransplanted human ovarian cancer cell lines that are thought to be of Mullerian origin. Because this highly lethal cancer has a high recurrence rate after conventional chemotherapy, new treatments are warranted. We examined whether rhMIS as a novel, nontoxic, naturally occurring growth inhibitor can be an effective anticancer drug in long-term studies in vivo against allograft tumors that recapitulate human ovarian carcinoma.

EXPERIMENTAL DESIGN

Mouse ovarian carcinoma (MOVCAR) cell lines expressing the early region of the SV40 virus, including the large and small T-antigen genes under transcriptional control of a portion of the murine MIS receptor type II (MISRII) gene promoter, were derived from TgMISIIR-TAg transgenic mice. rhMIS was tested against MOVCAR cells in growth inhibition assays in vitro, and in vivo in 6-week-old female nude mice. Tumor growth in animals was measured at weekly intervals for up to 20 weeks.

RESULTS

MOVCAR cells and tumors express MISRII by Western blot, immunohistochemical, and Northern blot analyses. rhMIS significantly inhibited MOVCAR cell growth in vitro and in vivo in three separate long-term allotransplantation experiments.

CONCLUSIONS

Because rhMIS is an effective anticancer agent in in vitro and in long-term in vivo preclinical experiments against MISRII-positive tumors, we predict that rhMIS can be used safely and effectively to treat human ovarian malignancies.

Mullerian inhibiting substance levels at the time of HCG administration in IVF cycles predict both ovarian reserve and embryo morphology

BACKGROUND

Pre-antral and early antral follicles secrete Müllerian inhibiting substance (MIS), suggesting that MIS may directly reflect ovarian reserve. Since little is known about how ovarian reserve affects oocyte quality, we attempt here to assess the predictive value of MIS on embryo morphology and IVF outcome. To do so, we measured MIS at the time of HCG administration 36 h prior to oocyte retrieval.

METHODS

A total of 257 patients undergoing IVF were prospectively recruited. We measured MIS levels by enzyme-linked immunosorbent assay at the time of HCG, and compared the MIS values to day 3 FSH levels in the prediction of embryo morphology and IVF outcome.

RESULTS

The distribution of MIS levels was skewed, with a median of 2.7 ng/ml (range 0 to 28.5 ng/ml). MIS values at the time of HCG administration inversely correlated with basal FSH levels (P = 0.002), and both correlated significantly with patient age, number of mature follicles, number of oocytes retrieved and serum estradiol levels. MIS levels correlated significantly with a greater number of 6-cell embryos and better embryo morphology score, while basal FSH levels did not correlate with these outcome variables. MIS levels > or =2.7 ng/ml portended improved oocyte quality as reflected in a higher implantation rate (P = 0.001) and a trend toward a better clinical pregnancy rate (P = 0.084).

CONCLUSIONS

MIS levels seem to predict not only ovarian reserve, but also embryo morphology. Measurement of MIS at the time of HCG administration may, therefore, in the future improve management of patients undergoing treatments with assisted reproductive technology.

Mullerian inhibiting substance suppresses tumor growth in the C3(1)T antigen transgenic mouse mammary carcinoma model

Mullerian inhibiting substance (MIS) inhibits breast cancer cell growth in vitro. To extend the use of MIS to treat breast cancer, it is essential to test the responsiveness of mammary tumor growth to MIS in vivo. Mammary tumors arising in the C3(1) T antigen mouse model expressed the MIS type II receptor, and MIS in vitro inhibited the growth of cells derived from tumors. Administration of MIS to mice was associated with a lower number of palpable mammary tumors compared with vehicle-treated mice (P=0.048), and the mean mammary tumor weight in the MIS-treated group was significantly lower compared with the control group (P=0.029). Analysis of proliferating cell nuclear antigen (PCNA) expression and caspase-3 cleavage in tumors revealed that exposure to MIS was associated with decreased proliferation and increased apoptosis, respectively, and was not caused by a decline in T antigen expression. The effect of MIS on tumor growth was also evaluated on xenografted human breast cancer cell line MDA-MB-468, which is estrogen receptor- and retinoblastoma-negative and expresses mutant p53, and thus complements the C3(1)Tag mouse mammary tumors that do not express estrogen receptor and have functional inactivation of retinoblastoma and p53. In agreement with results observed in the transgenic mice, MIS decreased the rate of MDA-MB-468 tumor growth and the gain in mean tumor volume in severe combined immunodeficient mice compared with vehicle-treated controls (P=0.004). These results suggest that MIS can suppress the growth of mammary tumors in vivo.

Endometrial cancer is a receptor-mediated target for Mullerian Inhibiting Substance

Mullerian Inhibiting Substance (MIS), a 140-kDa homodimer glycoprotein member of the TGF-beta superfamily of biological-response modifiers, causes regression of the Mullerian ducts in developing male embryos. MIS also can induce growth arrest and apoptosis in ovarian and cervical cancer cell lines. The embryonic progenitor of the ovarian and cervical epithelium is the coelomic epithelium, the same tissue that regresses under the direction of MIS in the male. The endometrium and uterus also arise from the coelomic epithelium and the Mullerian ducts. Here, we show that both normal human endometrium and endometrial cancers express the receptor for MIS and that MIS can inhibit the proliferation of a number of human endometrial cancer cell lines that express the MIS type II receptor. In the representative endometrial cancer cell line AN3CA, MIS affects the expression of key cell-cycle regulatory proteins. This work broadens the scope of tumors that MIS can potentially control and, by elucidating the MIS signaling pathway, identifies other potential avenues for intervention.

Metformin reduces serum m�llerian-inhibiting substance levels in women with polycystic ovary syndrome after protracted treatment

OBJECTIVE

Assessment of ovarian responses to metformin treatment in obese women with polycystic ovary syndrome (PCOS).

DESIGN

Prospective treatment with randomization to two doses of metformin.

SETTING

University teaching hospital.

PATIENT(S)

Obese women (n = 82) with PCOS.

INTERVENTION(S)

Markers of ovarian function were assessed after 4 and 8 months.

MAIN OUTCOME MEASURE(S)

Hormone (androgens and mullerian-inhibiting substance [MIS]) changes over time.

RESULT(S)

There was no difference in the reproductive hormone changes between the doses of metformin, and data were combined for further analyses. Significant responses to treatment were recorded for menstrual frequency and androstenedione (A) (reduction) within the first 4 months of treatment. However, suppression of the elevated circulating MIS concentrations required protracted treatment, because no change was observed in the first 4 months-only in the second 4-month assessment period.

CONCLUSION(S)

Metformin treatment of PCOS leads to rapid suppression of A and improved menstrual frequency. Suppression of MIS is a delayed response that may be secondary to the development of a cohort of follicles that underwent initial recruitment in an environment of reduced insulin stimulation.

Persistent Mullerian duct syndrome caused by both a 27-bp deletion and a novel splice mutation in the MIS type II receptor gene

BACKGROUND

Persistent Mullerian duct syndrome (PMDS) is a rare form of male pseudohermaphroditism that is characterized by the persistence of Mullerian derivatives in otherwise normally virilized males. Mutations of the Mullerian inhibiting substance (MIS) gene or the MIS type II receptor (MISRII) gene have been identified in PMDS patients with autosomal recessive transmission. We analyzed a compound heterozygote PMDS patient who had a 27-bp deletion in exon 10 in one allele and a novel mutation in intron 5 in the other allele of the MISRII gene.

METHODS

Whole blood and tissue samples were obtained from a one-month-old 46,XY male with persistent PMDS and the MISRII gene was sequenced and compared to his mother's genomic DNA and that of 22 normal individuals. Serum MIS and the reproductive hormones were measured by standard immunoassays.

RESULTS

The patient's hormone levels were normal but the gene for MISRII contained several mutations, a 27-bp deletion in exon 10 on one allele (one of the most common mutations in PMDS) and a novel mutation in intron 5 in the other allele that altered splicing, resulting in retention of the intron and a frameshift, introducing a stop codon. Other mutations in introns 6 and 9 and in exon 11 might not be functionally significant.

CONCLUSIONS

This case reveals a novel mutation in the MISRII gene involving intronic sequences, which when coexisting with the already identified 27-bp deletion in exon 10, leads to PMDS.

Enhanced purification and production of Müllerian inhibiting substance for therapeutic applications

It is almost 60 years since Prof. Alfred Jost reported the seminal observations regarding Müllerian inhibiting substance (MIS). His experiments clearly showed that a testicular product other than testosterone, a Müllerian inhibitor, was responsible for Müllerian duct regression. Twenty-five years later Dr. Picon established an organ culture assay which paved the way for the initial studies into the biochemistry and biology of Müllerian inhibiting substance, also known as Anti-Müllerian hormone (AMH), undertaken first in Dr. Nathalie Josso's Laboratory in Paris then in our own laboratory in Boston. Purification of MIS led to cloning the human gene and production of recombinant human (rhMIS). MIS is a 140 kDa glycoprotein homodimer which is activated by a biosynthetic protease, cleaving MIS into an aminoterminus (110 kDa) and a carboxyterminus (25 kDa). The latter domain is sufficient for biological activities. MIS functions by interacting with two receptors; a type II binds the hormone and at type I that initiates downstream signaling. The MIS type II receptor has been cloned and functionally confirmed as distinct from that of other members of the TGFbeta superfamily. MIS can employ a number of type I receptors (ALK2, ALK3, ALK6) and BMP receptor specific SMADS 1, 5, and 8 in various tissue specific contexts. Cell lines derived from human ovarian, breast, and prostate tumors, and from rodent Leydig cell tumors, which respond to MIS in growth inhibition assays, all express the MIS type II receptor. A variety of signal transduction pathways are associated with the grown inhibition mediated by MIS. For example, breast and prostate cancer cell lines use a MIS-mediated NFkappaB pathway leading to G1 arrest and apoptosis. The ovarian cancer cell lines employ a pathway which enhances p16, modulates the E2Fs, and induces apoptosis. These signal transduction events can establish new rational treatment strategies to complement the growth inhibitory effects mediated by MIS. These combination strategies are being tested in vitro, and where appropriate will be tested in vivo using the highly purified MIS preparations, prior to use in early human clinical trials.

MIS/AMH in the assessment of cryptorchidism and intersex conditions

Mullerian inhibiting substance (MIS), also known as anti-Mullerian hormone (AMH), causes Mullerian duct involution during male sexual differentiation and also has a postnatal regulatory role in the gonads. Serum MIS/AMH has a gonad specific pattern of expression and its concentrations are sexually dimorphic in children; hence measurement of serum MIS/AMH helps in the evaluation of children with gonadal disorders. In boys with cryptorchidism (non-palpable gonads), serum MIS/AMH correlates with testicular tissue. A measurable value is predictive of undescended testes while an undetectable value is highly suggestive of anorchia. In minimally virilized phenotypic females, MIS/AMH helps differentiate between gonadal and non-gonadal causes of virilization. In children with intersex conditions, MIS/AMH values assist differential diagnosis: a value above the normal female range is predictive of testicular tissue, while an undetectable value is suggestive of absent testicular tissue. Thus, MIS/AMH is useful for delineating gonadal pathology and facilitates the differential diagnosis and management of children with diverse gonadal disorders.

Mullerian Inhibiting Substance inhibits cervical cancer cell growth via a pathway involving p130 and p107

In addition to causing regression of the Mullerian duct in the male embryo, Mullerian Inhibiting Substance (MIS) inhibits the growth of epithelial ovarian cancer cells, which are known to be of Mullerian origin. Because the uterine cervix is derived from the same Mullerian duct precursor as the epithelium of the ovary, we tested the hypothesis that cervical cancer cells might also respond to MIS. A number of cervical cancer cell lines express the MIS type II receptor, and MIS inhibits the growth of both human papilloma virus-transformed and non-human papilloma virus-transformed cervical cell lines, with a more dramatic effect seen in the latter. As in the ovarian cancer cell line OVCAR8, suppression of growth of the C33A cervical cancer cell line by MIS is associated with induction of the p16 tumor suppressor protein. However, in contrast to OVCAR8 cells, induction of p130 and p107 appears to play an important role in the inhibition of growth of C33A cells by MIS. Finally, normal cervical tissue expresses the MIS type II receptor in vivo, supporting the idea that MIS could be a targeted therapy for cervical cancer.

Müllerian-inhibiting substance inhibits rat Leydig cell regeneration after ethylene dimethanesulphonate ablation

The postnatal development of Leydig cell precursors is postulated to be controlled by Sertoli cell secreted factors, which may have a determinative influence on Leydig cell number and function in sexually mature animals. One such hormone, Mullerian inhibiting substance (MIS), has been shown to inhibit DNA synthesis and steroidogenesis in primary Leydig cells and Leydig cell tumor lines. To further delineate the effects of MIS on Leydig cell proliferation and steroidogenesis, we employed the established ethylene dimethanesulphonate (EDS) model of Leydig cell regeneration. Following EDS ablation of differentiated Leydig cells in young adult rats, recombinant MIS or vehicle was delivered by intratesticular injection for 4 days (Days 11-14 after EDS). On Days 15 and 35 after EDS (1 and 21 days post-MIS injections), endocrine function was assessed and testes were collected for stereology, immunohistochemistry, and assessment of proliferation and steroidogenesis. Although serum testosterone and luteinizing hormone (LH) were no different, intratesticular testosterone was higher on Day 35 in MIS-treated animals. At both time points, intratesticular 5alpha-androstan-3alpha,17beta-diol concentrations were much higher than that of testosterone. MIS-treated animals had fewer mesenchymal precursors on Day 15 and fewer differentiated Leydig cells on Day 35 with decreased numbers of BrdU+ nuclei. Apoptotic interstitial cells were observed only in the MIS-treated testes, not in the vehicle-treated group on Day 15. These data suggest that MIS inhibits regeneration of Leydig cells in EDS-treated rats by enhancing apoptotic cell death as well as by decreasing proliferative capacity.

Mullerian inhibiting substance: an update

The decades long study of Mullerian Inhibiting Substance by numerous laboratories around the world has been driven, in large part, by pediatric surgeons and pediatric endocrinologists who have a keen interest in the molecular pathophysiology of genital tract defects that are visited upon their patients. A better understanding of the genes involved in the development of the normal reproductive tract in males and females should lead to a more rational analysis of the diseases caused by their abnormal function. Furthermore, a translation of this knowledge from the bench to the bedside may lead to clinically useful advances in the diagnosis and management of intersex patients. The molecular analyses of MIS and MIS receptor gene mutations and persistent Mullerian duct syndrome and the development of MIS ELISAs to evaluate testicular function as well as to follow the progress of gonadal tumors are several clear examples of successes over the years. It will be interesting to see what lies ahead.

The role of Müllerian inhibiting substance in the evaluation of phenotypic female patients with mild degrees of virilization

Müllerian inhibiting substance (MIS) is a sexually dimorphic gonadal hormone with proven efficacy in the evaluation of boys with cryptorchidism and children with intersex conditions. We examined the role of MIS determination in the evaluation of 65 phenotypic females with mild virilization. Among the 28 subjects with MIS values elevated above the normal female range, all had abnormal gonadal tissue: ovotestes in 11, testes in 7, dysgenetic gonads in 7, and MIS-secreting ovarian tumors in 3. Among the 37 children with serum MIS in the normal female range, 19 had detectable MIS and 18 had unmeasurable MIS. In the former group with measurable but normal female MIS values, 16 subjects had ovaries, 1 had an ovotestis, and 1 had dysgenetic gonads containing testicular elements. Of 18 children with undetectable MIS values, 16 had ovaries and 2 had ovarian dysgenesis. In this study, elevation of serum MIS above the normal female range was consistently associated with the presence of testicular tissue or MIS- secreting tumors, mandating additional evaluation and surgical exploration. A value within the normal female range in a virilized patient did not exclude dysgenetic testicular tissue or ovotestis, whereas undetectable values were consistent with the absence of testicular tissue.

Highly purified müllerian inhibiting substance inhibits human ovarian cancer in vivo

PURPOSE

Müllerian inhibiting substance (MIS) causes Müllerianduct regression in mammalian, avian, and reptilian embryos; MIS also inhibits growth in vitro of Müllerian-derived cell lines and primary cells from human ovarian carcinomas. We hypothesize that highly purified MIS delivered parenterally inhibits ovarian cancer in vivo.

EXPERIMENTAL DESIGN

To test the efficacy of highly purified MIS against ovarian cancer cell lines in vivo, we treated immunosuppressed mice with MIS after implanting OVCAR 8 or IGROV 1 human ovarian cancer cells beneath the renal capsules and measured tumor volume over time. Animals were treated with daily injections of 10 micro g of purified exogenous recombinant human MIS or by endogenous MIS secreted from cells growing on biodegradable mesh.

RESULTS

The average graft size ratio (change in size compared with starting size) of the OVCAR 8 tumor implants was larger in the control animals than in animals treated for 2 weeks (P < 0.019) or 3 weeks (P < 0.001) with parenteral MIS, or after treating with MIS produced from transfected cells, which impregnated the biodegradable mesh (P = 0.02). The average graft size ratio of the IGROV 1 tumors was also larger in the control animals than in those treated with injected MIS (P = 0.0174).

CONCLUSIONS

Highly purified recombinant human MIS, delivered parenterally, or MIS produced endogenously causes inhibition of human ovarian cancer cell lines in vivo, providing convincing preclinical evidence to support the use of MIS as a parenteral agent for the treatment of ovarian cancer.

Measurement of Mullerian inhibiting substance facilitates management of boys with microphallus and cryptorchidism

Mullerian inhibiting substance (MIS) is a gonadal hormone expressed in a sexually dimorphic pattern. In males, serum MIS reflects Sertoli cell function and provides an estimate of seminiferous tubular integrity. We examined the role of MIS determination in the evaluation of boys with microphallus (n = 62) and/or cryptorchidism (n = 156). MIS was normal in 69.2% of boys with isolated microphallus compared with 38.1% of boys with microphallus and coexisting cryptorchidism (P < 0.05). In the cryptorchid group, MIS was normal in 46.8%, low in 24.4%, and absent in 28.8%. Normal values for age were associated with testicular tissue, whereas undetectable values were indicative of anorchia, except for two boys with MIS gene mutations (persistent Mullerian duct syndrome). These data demonstrated that a basal MIS measurement is more specific and has a higher positive predictive value than stimulated testosterone values for ascertaining the absence of testes (anorchia). In summary, a normal serum MIS concentration in the prepubertal child is a reliable determinant of testicular tissue, whereas an undetectable value is a highly sensitive initial screening test for anorchia. We conclude that preoperative measurement of MIS facilitates the management of children with cryptorchidism and intersex disorders and offers a measure of Sertoli cell function.

Early follicular serum müllerian-inhibiting substance levels are associated with ovarian response during assisted reproductive technology cycles

OBJECTIVE

To test the hypothesis that the concentration of early follicular phase serum müllerian-inhibiting substance (MIS) is associated with ovarian response in women undergoing ovulation induction in preparation for assisted reproductive technology (ART).

DESIGN

Retrospective analysis of frozen day 3 serum samples.

SETTING

Academic ART program.

PATIENT(S)

One sample of frozen day 3 serum from women with < or = 6 retrieved oocytes (n = 28) compared with women with > or = 11 oocytes retrieved (n = 79) in preparation for IVF.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Comparison of day 3 serum MIS levels between two groups of women. Other comparisons included maximum serum E(2) concentrations, number of retrieved oocytes, and percentage of mature oocytes between groups.

RESULT(S)

Mean serum MIS concentrations were 1.0 +/- 0.4 ng/mL compared with 2.5 +/- 0.3 ng/mL, or more than a 2.5-fold greater serum concentration of MIS in the group with > or = 11 oocytes retrieved compared with in the group with < or = 6 retrieved oocytes.

CONCLUSION(S)

These data demonstrate an association between early follicular phase serum MIS and the number of retrieved oocytes. Higher day 3 serum MIS concentrations were associated with greater number of retrieved oocytes.

Mullerian-inhibiting substance regulates NF-kappa B signaling in the prostate in vitro and in vivo

Mullerian-inhibiting substance (MIS) is a member of the transforming growth factor beta superfamily, a class of molecules that regulates growth, differentiation, and apoptosis in many cells. MIS type II receptor in the Mullerian duct is temporally and spatially regulated during development and becomes restricted to the most caudal ends that fuse to form the prostatic utricle. In this article, we have demonstrated MIS type II receptor expression in the normal prostate, human prostate cancer cell lines, and tissue derived from patients with prostate adenocarcinomas. MIS induced NF-kappaB DNA binding activity and selectively up-regulated the immediate early gene IEX-1S in both androgen-dependent and independent human prostate cancer cells in vitro. Dominant negative IkappaBalpha expression ablated both MIS-induced increase of IEX-1S mRNA and inhibition of growth, indicating that activation of NF-kappaB signaling was required for these processes. Androgen also induced NF-kappaB DNA binding activity in prostate cancer cells but without induction of IEX-1S mRNA, suggesting that MIS-mediated increase in IEX-1S was independent of androgen-mediated signaling. Administration of MIS to male mice induced IEX-1S mRNA in the prostate in vivo, suggesting that MIS may function as an endogenous hormonal regulator of NF-kappaB signaling and growth in the prostate gland.

New approaches for high-yield purification of Müllerian inhibiting substance improve its bioactivity

We have established a new method to purify Müllerian inhibiting substance (MIS) with higher purity and recovery over existing procedures. Recombinant human MIS was expressed in Chinese hamster ovary cells and secreted into chemically defined serum-free media. The secreted products were concentrated by either precipitation with ammonium sulfate or lectin-affinity chromatography, each of which was followed by anion-exchange chromatography. Further separation of the active carboxy-terminal domain of MIS was achieved after cleavage by plasmin followed by lectin-affinity chromatography. This method may be applicable to other members of the transforming growth factor beta family with which MIS shares sequence homology.

The role of prior pubertal development, biochemical markers of testicular maturation, and genetics in elucidating the phenotypic heterogeneity of idiopathic hypogonadotropic hypogonadism

As our knowledge of the molecular mechanisms underlying idiopathic hypogonadotropic hypogonadism (IHH) expands, it becomes increasingly important to define the phenotypic spectrum of IHH. In this study we examined historical, clinical, biochemical, histological, and genetic features in 78 men with IHH to gain further insight into the phenotypic heterogeneity of the syndrome. We hypothesized that at least some of the spectrum of phenotypes could be explained by placing the disorder into a developmental and genetic context. Thirty-eight percent of the population had Kallmann syndrome (KS; IHH with anosmia), 54% had normosmic IHH, and 8% had acquired IHH after completion of puberty. Phenotypically, KS represented the most severe subtype (87% with complete absence of any history or signs of spontaneous pubertal development), normosmic IHH displayed the most heterogeneity (41% with some evidence of spontaneous puberty), and acquired IHH after completion of puberty clustered at the mildest end (all had complete puberty). Classification based on historical or clinical evidence of prior pubertal development, rather than the presence or absence of sense of smell, served to distinguish the population more clearly with respect to other clinical and biochemical features. Comparing IHH patients according to the absence (68%) or presence (24%) of some prior pubertal development revealed significant differences in testicular size (3.3 +/- 0.2 vs. 11.8 +/- 1.2 ml; P < 0.001), incidence of cryptorchidism (40% vs. 5%; P < 0.05), microphallus (21% vs. 0%; P < 0.05), inhibin B levels (45 +/- 4 vs. 144 +/- 20 pg/ml; P < 0.0001), and Mullerian inhibitory substance levels (9.8 +/- 1.4 vs. 2 +/- 0.5 ng/ml). Most familial cases had no pubertal development (95% vs. 5%; P < 0.001); males with mutations in the KAL gene displayed the most severe phenotype. Mean gonadotropins levels (LH, 1.8 +/- 0.1 vs. 2.9 +/- 0.4 IU/liter; FSH, 2.2 +/- 0.2 vs. 3.3 +/- 0.3 IU/liter; P < 0.05) and the finding of apulsatile LH secretion based on frequent sampling (80% vs. 55%; P < 0.05) were statistically different between patients lacking and those exhibiting partial pubertal development, but the overlap was extensive. The use of clinical parameters (presence or absence of some evidence of prior pubertal development, cryptorchidism, and microphallus), biochemical markers of testicular growth and differentiation (inhibin B and Mullerian inhibitory substance), and genetic evidence provides insight into the time of onset and the severity of GnRH deficiency. Viewing IHH in the full context of its developmental, genetic, and biochemical complexity permits greatest insight into its phenotypic variability.

Müllerian inhibiting substance inhibits testosterone synthesis in adult rats

Müllerian inhibiting substance (MIS) is a gonadal hormone that causes regression of the Müllerian ducts during male sexual differentiation. Postnatally, MIS inhibits the proliferation and differentiation of immature Leydig cells, and transgenic mice that overexpress MIS have decreased serum testosterone concentrations. To elucidate the effects of MIS on androgen regulation in the postnatal testis, we examined testosterone synthesis in adult Sprague-Dawley rats following intratesticular and intraperitoneal injections of MIS. Intratesticular MIS injection achieved high local concentrations of MIS (574.0 +/- 60.0 ng/mL) at 4 hours, with a corresponding decline in serum testosterone concentrations to 0.7 +/- 0.1 ng/mL, compared to 1.1 +/- 0.2 ng/mL with intraperitoneal MIS and 1.6 +/- 0.1 ng/mL with intratesticular vehicle (IT-Veh) (P < .001). Intratesticular administration of MIS (IT-MIS) resulted in much higher serum and testicular interstitial fluid MIS concentrations than the intraperitoneal route. To directly examine the testosterone production rate in MIS-treated animals, we isolated Leydig cells from MIS and vehicle-injected testes. Primary Leydig cells exposed to MIS had a lower testosterone production rate and decreased expression of p450c17 (hydroxylase/lyase) and luteinizing hormone (LH) receptor mRNAs than that of vehicle-injected controls or the noninjected contralateral testis. In conclusion, intratesticular administration of MIS caused a decline in serum testosterone concentrations by decreasing the rate of testosterone biosynthesis, confirming that MIS can regulate adult Leydig cell androgen production. The ability of MIS to down-regulate mRNA expression of the p450c17 and LH receptor genes suggests that this effect is mediated transcriptionally. These data indicate that, in addition to its role in embryonic differentiation of the male reproductive tract, MIS has a regulatory function in the postnatal testis. We conclude that one such function is for MIS to directly inhibit adult Leydig cell steroidogenesis.

Mullerian inhibiting substance regulates NFkappaB signaling and growth of mammary epithelial cells in vivo

Müllerian inhibiting substance (MIS) inhibits breast cancer cell growth in vitro through interference with cell cycle progression and induction of apoptosis, a process associated with NFkappaB activation and up-regulation of one of its important target genes, IEX-1S (Segev, D. L., Ha, T., Tran, T. T., Kenneally, M., Harkin, P., Jung, M., MacLaughlin, D. T., Donahoe, P. K., and Maheswaran, S. (2000) J. Biol. Chem. 275, 28371-28379). Here we demonstrate that MIS activates the NFkappaB signaling cascade, induces IEX-1S mRNA, and inhibits the growth of MCF10A, an immortalized human breast epithelial cell line with characteristics of normal cells. In vivo, an inverse correlation was found to exist between various stages of mammary growth and MIS type II receptor expression. Receptor mRNA significantly diminished during puberty, when the ductal system branches and invades the adipose stroma and during the expansive growth at lactation, but it was up-regulated during involution, a time of regression and apoptosis. Peripartum variations in MIS type II receptor expression correlated with NFkappaB activation and IEX-1S mRNA expression. Administration of MIS to female mice induced NFkappaB DNA binding and IEX-1S mRNA expression in the breast. Furthermore, exposure to MIS in vivo increased apoptosis in the mouse mammary ductal epithelium. Thus, MIS may function as an endogenous hormonal regulator of NFkappaB signaling and growth in the breast.

Müllerian Inhibiting Substance lowers testosterone in luteinizing hormone-stimulated rodents

Müllerian Inhibiting Substance (MIS) expression is inversely proportional to the serum concentration of testosterone in males after birth and in vitro studies have shown that MIS can lower testosterone production by Leydig cells. Also, mice overexpressing MIS exhibited Leydig cell hypoplasia and lower levels of serum testosterone, but it is not clear whether this is a result of MIS affecting the development of Leydig cells or their capacity to produce testosterone. To examine the hypothesis that MIS treatment will result in decreased testosterone production by mature Leydig cells in vivo, we treated luteinizing hormone (LH)-stimulated adult male rats and mice with MIS and demonstrated that it can lead to a several-fold reduction in testosterone in serum and in testicular extracts. There was also a slight decrease in 17-OH-progesterone compared to the more significant decrease in testosterone, suggesting that MIS might be regulating the lyase activity of cytochrome P450c17 hydroxylase/lyase (Cyp17), but not its hydroxylase activity. Northern analysis showed that, in both MIS-treated rats and mice, the mRNA for Cyp17, which catalyzes the committed step in androgen synthesis, was down-regulated. In rats, the mRNA for cytochrome P450 side-chain cleavage (P450scc) was also down-regulated by MIS. This was not observed in mice, indicating that there might be species-specific regulation by MIS of the enzymes involved in the testosterone biosynthetic pathway. Our results show that MIS can be used in vivo to lower testosterone production by mature rodent Leydig cells and suggest that MIS-mediated down-regulation of the expression of Cyp17, and perhaps P450scc, contributes to that effect.

Tissue-engineered cells producing complex recombinant proteins inhibit ovarian cancer in vivo

Techniques of tissue engineering and cell and molecular biology were used to create a biodegradable scaffold for transfected cells to produce complex proteins. Mullerian Inhibiting Substance (MIS) causes regression of Mullerian ducts in the mammalian embryo. MIS also causes regression in vitro of ovarian tumor cell lines and primary cells from ovarian carcinomas, which derive from Mullerian structures. In a strategy to circumvent the complicated purification protocols for MIS, Chinese hamster ovary cells transfected with the human MIS gene were seeded onto biodegradable polymers of polyglycolic acid fibers and secretion of MIS confirmed. The polymer-cell graft was implanted into the right ovarian pedicle of severe combined immunodeficient mice. Serum MIS in the mice rose to supraphysiologic levels over time. One week after implantation of the polymer-cell graft, IGROV-1 human tumors were implanted under the renal capsule of the left kidney. Growth of the IGROV-1 tumors was significantly inhibited in the animals with a polymer-cell graft of MIS-producing cells, compared with controls. This novel MIS delivery system could have broader applications for other inhibitory agents not amenable to efficient purification and provides in vivo evidence for a role of MIS in the treatment of ovarian cancer.

Mullerian inhibiting substance inhibits breast cancer cell growth through an NFkappa B-mediated pathway

Müllerian inhibiting substance (MIS), a member of the transforming growth factor-beta superfamily, induces regression of the Müllerian duct in male embryos. In this report, we demonstrate MIS type II receptor expression in normal breast tissue and in human breast cancer cell lines, breast fibroadenoma, and ductal adenocarcinomas. MIS inhibited the growth of both estrogen receptor (ER)-positive T47D and ER-negative MDA-MB-231 breast cancer cell lines, suggesting a broader range of target tissues for MIS action. Inhibition of growth was manifested by an increase in the fraction of cells in the G(1) phase of the cell cycle and induction of apoptosis. Treatment of breast cancer cells with MIS activated the NFkappaB pathway and selectively up-regulated the immediate early gene IEX-1S, which, when overexpressed, inhibited breast cancer cell growth. Dominant negative IkappaBalpha expression ablated both MIS-mediated induction of IEX-1S and inhibition of growth, indicating that activation of the NFkappaB signaling pathway was required for these processes. These results identify the NFkappaB-mediated signaling pathway and a target gene for MIS action and suggest a putative role for the MIS ligand and its downstream interactors in the treatment of ER-positive as well as negative breast cancers.

A time-less function for mouse timeless

The timeless (tim) gene is essential for circadian clock function in Drosophila melanogaster. A putative mouse homolog, mTimeless (mTim), has been difficult to place in the circadian clock of mammals. Here we show that mTim is essential for embryonic development, but does not have substantiated circadian function.

Human ovarian cancer, cell lines, and primary ascites cells express the human Mullerian inhibiting substance (MIS) type II receptor, bind, and are responsive to MIS

Six human ovarian cancer cell lines and samples of ascites cells isolated from 27 patients with stage III or IV ovarian papillary serous cystadenocarcinoma were studied individually to test whether recombinant human Mullerian inhibiting substance (rhMIS) acts via its receptor. To do these experiments, we scaled up production of rhMIS and labeled it successfully with biotin for binding studies, cloned the human MIS type II receptor for mRNA detection, and raised antibodies to an extracellular domain peptide for protein detection. These probes were first tested on the human ovarian cancer cell lines and then applied to primary ovarian ascites cells. rhMIS inhibited colony growth of five of six cell lines that expressed the human MIS type II receptor mRNA by Northern analysis while not inhibiting receptor-negative COS cells. Flow cytometry performed on MIS-sensitive ovarian cancer cell lines demonstrated specific and saturable binding of rhMIS (Kd = 10.2 nM). Ascites cells from 15 of 27 or 56% of patients tested bound biotinylated MIS (MIS-biotin) and, of the 11 that grew in soft agarose, 9 of 11 or 82% showed statistically significant inhibition of colony formation. Of the 15 patients who bound biotinylated MIS, mRNA was available for analysis from 9, and 8 of 9 expressed MIS type II receptor mRNA by reverse transcription-PCR, showing a statistically significant correlation, compared with binding, by chi2 analysis (P = 0.025). Solid ovarian cancers were positive for the MIS type II receptor protein by immunohistochemical staining, which colocalized with staining for antibody to CA-125 (OC-125). Thus, the detection of the MIS type I receptor by flow cytometry may be a useful predictor of therapeutic response to MIS and may be a modality to rapidly choose patients with late-stage ovarian cancer for treatment with MIS.

The type I serine/threonine kinase receptor ActRIA (ALK2) is required for gastrulation of the mouse embryo

ActRIA (or ALK2), one of the type I receptors of the transforming growth factor-beta (TGF-beta) superfamily, can bind both activin and bone morphogenetic proteins (BMPs) in conjunction with the activin and BMP type II receptors, respectively. In mice, ActRIA is expressed primarily in the extraembryonic visceral endoderm before gastrulation and later in both embryonic and extraembryonic cells during gastrulation. To elucidate its function in mouse development, we disrupted the transmembrane domain of ActRIA by gene targeting. We showed that embryos homozygous for the mutation were arrested at the early gastrulation stage, displaying abnormal visceral endoderm morphology and severe disruption of mesoderm formation. To determine in which germ layer ActRIA functions during gastrulation, we performed reciprocal chimera analyses. (1) Homozygous mutant ES cells injected into wild-type blastocysts were able to contribute to all three definitive germ layers in chimeric embryos. However, a high contribution of mutant ES cells in chimeras disrupted normal development at the early somite stage. (2) Consistent with ActRIA expression in the extraembryonic cells, wild-type ES cells failed to rescue the gastrulation defect in chimeras in which the extraembryonic ectoderm and visceral endoderm were derived from homozygous mutant blastocysts. Furthermore, expression of HNF4, a key visceral endoderm-specific transcription regulatory factor, was significantly reduced in the mutant embryos. Together, our results indicate that ActRIA in extraembryonic cells plays a major role in early gastrulation, whereas ActRIA function is also required in embryonic tissues during later development in mice.

Diagnostic utility of Müllerian inhibiting substance determination in patients with primary and recurrent granulosa cell tumors

OBJECTIVES

In this study we evaluated changes in serum Müllerian inhibiting substance (MIS) concentration in a large number of patients with granulosa cell tumors (GCT) to determine whether MIS is elevated at the time of presentation and whether MIS is an index of successful surgical resection and management of recurrences.

METHODS

We retrospectively reviewed MIS levels from 17 subjects prior to tumor resection and studied serial MIS samples from 56 subjects following initial tumor resection. Clinical follow-up information was available for 36 of those with postoperative MIS values. Serum MIS was measured by an ELISA. MIS values were compared to a combination of normative values previously established in our laboratory and from more recently obtained samples from older pre- and postmenopausal women, using this assay.

RESULTS

Serum MIS was elevated pre-operatively in 6 of 8 (75%) subjects with juvenile GCTs and in 7 of 9 (78%) of those with adult GCTs relative to age-matched controls (76% for both types combined). Post-operative clinical correlation was available for 36 patients. There was no clinical recurrence in 21 subjects with normal or undetectable postoperative values, and incompletely resectable tumor or recurrence was identified in 6 of 15 patients with elevated postoperative values.

CONCLUSIONS

The results of this study demonstrate that postoperative serum MIS concentrations may be used to evaluate the completeness of tumor removal following initial surgery and that serial MIS determinations may allow the detection of recurrences.

The presence of Müllerian inhibiting substance binding sites in human sperm

PURPOSE

The binding of Müllerian inhibiting substance (MIS) to human sperm was investigated using immunohistological techniques.

MATERIALS AND METHODS

Sperm from 5 normal donors and 6 subfertile men were studied. Whole or thin-sectioned sperm were incubated without or with recombinant human MIS (0.5 microg./ml.). MIS binding was identified under light microscopy (LM) using rabbit anti-human MIS antibodies tagged with goat IgG-horseradish peroxidase and diaminobenzidine as substrate, or by scanning and transmission electron microscopy (SEM and TEM) using gold labeled goat IgG. Intracellular MIS binding in sperm sections was examined by TEM. Antibodies were omitted in the controls.

RESULTS

Under LM, DAB staining was present on sperm incubated with or without MIS and absent on controls. Using SEM, gold particles were found primarily on the surfaces of the sperm head with less binding to the tail. With TEM, the clustering of gold particles around the head of sperm represents MIS binding, but very few or no gold particles could be found associated with the sperm tail. MIS binding was also found associated with intracellular structures, but only within the head of the sperm. Overall, less gold particle binding was present in subfertile compared with normal sperm.

CONCLUSIONS

These results suggest that MIS is bound to the sperm surface and sperm from normally fertile men have increased MIS binding. The function of MIS in sperm is unknown, but the presence of MIS binding suggests a direct role(s) in sperm function.

Measurements of serum müllerian inhibiting substance in the evaluation of children with nonpalpable gonads

BACKGROUND

Müllerian inhibiting substance, produced constitutively by the prepubertal testes, promotes involution of the müllerian ducts during normal male sexual differentiation. In children with virilization and nonpalpable gonads, only those with testicular tissue should have detectable serum concentrations of müllerian inhibiting substance.

METHODS

We measured serum mullerian inhibiting substance in 65 children with virilization at birth and nonpalpable gonads (age at diagnosis, 2 days to 11 years) and serum testosterone in 54 of them either after the administration of human chorionic gonadotropin or during the physiologic rise in testosterone that occurs in normal infants.

RESULTS

The mean (+/-SD) serum mullerian inhibiting substance concentration in the 17 children with no testicular tissue was 0.7+/-0.5 ng per milliliter, as compared with 37.5+/-39.6 ng per milliliter in the 48 children with testes (P<0.001). In the latter group, the mean values in the 14 children with abnormal testes and the 34 with normal testes were 11.5+/-11.8 and 48.2+/-42.1 ng per milliliter, respectively (P< 0.001). The sensitivity and specificity of the serum müllerian inhibiting substance assay for detecting the absence of testicular tissue were 92 percent and 98 percent, respectively, as compared with 69 percent and 83 percent for the measurement of serum testosterone. Furthermore, measurement of serum mullerian inhibiting substance was more sensitive than serum testosterone measurement for the identification of children with abnormal testes (67 percent vs. 25 percent), whereas the specificity of the two tests was similar.

CONCLUSIONS

Measurements of serum mullerian inhibiting substance can be used to determine testicular status in prepubertal children with nonpalpable gonads, thus differentiating anorchia from undescended testes in boys with bilateral cryptorchidism and serving as a measure of testicular integrity in children with intersexual anomalies.

The presence of müllerian inhibiting substance in human seminal plasma

Müllerian inhibiting substance (MIS), produced by testicular Sertoli cells, is present in adult male serum. The first aim of this study was to determine if MIS is present in seminal plasma. Using an enzyme-linked immunosorbent assay (ELISA), we measured MIS concentrations in seminal plasma from 23 donors exhibiting normal (WHO criteria) sperm qualities, and 169 patients with subnormal sperm parameters. The second aim of this study was to examine a potential relationship between MIS and sperm motility. MIS concentrations in seminal plasma ranged from 0.5 to 3.6 ng/ml in donors and from 0.5 to 17.8 ng/ml in patients. Motility index (MI, mean +/- SEM) for all patient samples was lower compared with donors (113.3 +/- 3.2 and 198.3 +/- 13.5, P < 0.00001), while mean MIS concentration +/- SEM) was higher (4.2 +/- 0.3 and 1.4 +/- 0.2, P < 0.0003). When the patients were stratified into Groups I (motility < 50%, n = 42) and II (motility > 50%, n = 127), the MI (mean +/- SEM) values were 62.3 +/- 3.8 and 130.2 +/- 2.7 respectively (P < 0.0001 for both compared with donors) and mean MIS concentrations (+/- SEM) were 5.4 +/- 0.6 and 3.9 +/- 0.3, respectively (P < 0.0001 and P < 0.001 compared with donors). The inverse relationship between MIS concentration in seminal plasma and motility index suggests that MIS may have a function in modulating motility.

Mullerian inhibiting substance in humans: normal levels from infancy to adulthood

Mullerian-inhibiting substance (MIS) is a gonadal hormone synthesized by Sertoli cells of the testis and granulosa cells of the ovary. To facilitate the use of MIS for the evaluation of intersex disorders and as a tumor marker in women with MIS-expressing ovarian tumors, we measured MIS in 600 serum samples from males and females. These data show that mean MIS values for males rise rapidly during the first year of life and are highest during late infancy, then gradually decline until puberty. In contrast, MIS values in females are lowest at birth and exhibit a minimal increase throughout the prepubertal years. Whereas MIS is uniformly measurable in all prepubertal boys studied, it is undetectable in most prepubertal female subjects. These data reveal an easily discernible sexually dimorphic pattern of expression and confirm that MIS can be used as a testis-specific marker during infancy and early childhood. MIS values that are above the upper limits for females are discriminatory for the presence of testicular tissue or ovarian tumor, and those below the lower limits for males are consistent with dysgenetic or absent testes or the presence of ovarian tissue. These data will enable normal and abnormal levels of MIS to be differentiated with higher precision and will facilitate the use of MIS in the management of gonadal disorders.