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.

Human ovarian cancer stem/progenitor cells are stimulated by doxorubicin but inhibited by Mullerian inhibiting substance.

Women with late-stage ovarian cancer usually develop chemotherapeutic-resistant recurrence. It has been theorized that a rare cancer stem cell, which is responsible for the growth and maintenance of the tumor, is also resistant to conventional chemotherapeutics. We have isolated from multiple ovarian cancer cell lines an ovarian cancer stem cell-enriched population marked by CD44, CD24, and Epcam (3+) and by negative selection for Ecadherin (Ecad-) that comprises less than 1% of cancer cells and has increased colony formation and shorter tumor-free intervals in vivo after limiting dilution. Surprisingly, these cells are not only resistant to chemotherapeutics such as doxorubicin, but also are stimulated by it, as evidenced by the significantly increased number of colonies in treated 3+Ecad- cells. Similarly, proliferation of the 3+Ecad- cells in monolayer increased with treatment, by either doxorubicin or cisplatin, compared with the unseparated or cancer stem cell-depleted 3-Ecad+ cells. However, these cells are sensitive to Mullerian inhibiting substance (MIS), which decreased colony formation. MIS inhibits ovarian cancer cells by inducing G1 arrest of the 3+Ecad- subpopulation through the induction of cyclin-dependent kinase inhibitors. 3+Ecad- cells selectively expressed LIN28, which colocalized by immunofluorescence with the 3+ cancer stem cell markers in the human ovarian carcinoma cell line, OVCAR-5, and is also highly expressed in transgenic murine models of ovarian cancer and in other human ovarian cancer cell lines. These results suggest that chemotherapeutics may be stimulative to cancer stem cells and that selective inhibition of these cells by treating with MIS or targeting LIN28 should be considered in the development of therapeutics.

Mullerian inhibiting substance preferentially inhibits stem/progenitors in human ovarian cancer cell lines compared with chemotherapeutics.

Cancer stem cells are proposed to be tumor-initiating cells capable of tumorigenesis, recurrence, metastasis, and drug resistance, and, like somatic stem cells, are thought to be capable of unlimited self-renewal and, when stimulated, proliferation and differentiation. Here we select cells by expression of a panel of markers to enrich for a population with stem cell-like characteristics. A panel of eight was initially selected from 95 human cell surface antigens as each was shared among human ovarian primary cancers, ovarian cancer cell lines, and normal fimbria. A total of 150 combinations of markers were reduced to a panel of three--CD44, CD24, and Epcam--which selected, in three ovarian cancer cell lines, those cells which best formed colonies. Cells expressing CD44, CD24, and Epcam exhibited stem cell characteristics of shorter tumor-free intervals in vivo after limiting dilution, and enhanced migration in invasion assays in vitro. Also, doxorubicin, cisplatin, and paclitaxel increased this enriched population which, conversely, was significantly inhibited by Müllerian inhibiting substance (MIS) or the MIS mimetic SP600125. These findings demonstrate that flow cytometry can be used to detect a population which shows differential drug sensitivity, and imply that treatment of patients can be individualized to target both stem/progenitor cell enriched and nonenriched subpopulations. The findings also suggest that this population, amenable to isolation by flow cytometry, can be used to screen for novel treatment paradigms, including biologic agents such as MIS, which will improve outcomes for patients with ovarian cancer.

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

Ovarian granulosa cell tumors (GCTs) are sex cord stromal tumors that constitute 3-5% of all ovarian cancers. GCTs usually present with an indolent course but there is a high risk of recurrence, which associates with increased mortality, and targeted treatments would be desirable. Anti-Müllerian hormone (AMH), a key factor regulating sexual differentiation of the reproductive organs, has been implicated as a growth inhibitor in ovarian cancer. GCTs and normal granulosa cells produce AMH, but its expression in large GCTs is usually downregulated. Further, as the lack of specific AMH-signaling pathway components leads to GCT development in mice, we hypothesized that AMH inhibits growth of GCTs. Utilizing a large panel of human GCT tissue samples, we found that AMH type I receptors (ALK2, ALK3 and ALK6) and type II receptor (AMHRII), as well as their downstream effectors Smad1/5, are expressed and active in GCTs. AMHRII expression was detected in the vast majority (96%) of GCTs and correlated with AMH mRNA and protein expression. AMH mRNA level was low in large GCTs, confirming previous findings on low-AMH protein expression in large human as well as mouse GCTs. To study the functional role of AMH in this peculiar ovarian cancer, we utilized a human GCT cell line (KGN) and 10 primary GCT cell cultures. We found that the AMH-Smad1/5-signaling pathway was active in these cells, and that exogenous AMH further activated Smad1/5 in KGN cells. Furthermore, AMH treatment reduced the number of KGN cells and primary GCT cells, with increasing amounts of AMH leading to augmented activation of caspase-3 and subsequent apoptosis. All in all, these data support the premise that AMH is a growth inhibitor of GCTs.

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.

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.

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.

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.

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.

Serum Müllerian Inhibiting Substance/anti-Müllerian hormone levels in patients with adult granulosa cell tumors directly correlate with aggregate tumor mass as determined by pathology or radiology.

OBJECTIVES: Granulosa cell tumors (GCTs) comprise 2-5% of ovarian tumors. Serum Müllerian Inhibiting Substance (MIS, also known as anti-Müllerian hormone, or AMH) levels have been validated as a marker of GCT recurrence and progression. There has been little correlation between serum MIS/AMH levels and several clinical parameters in GCTs, including tumor burden. We have performed a retrospective review correlating aggregate tumor mass as reported by pathologic examination or by radiology with serum MIS/AMH levels drawn on the date of examination. METHODS: We retrospectively identified 32 GCT patients at our institution over the last 15 years who had serum MIS/AMH measurements. Patients who had serum MIS/AMH measurements within three days of surgery or on the same day as abdominal computerized tomography scan (CT) or magnetic resonance imaging (MRI) were further evaluated. RESULTS: We found a significant direct correlation between patient serum MIS/AMH levels and gross aggregate tumor mass determined by pathology (slope=15.4+/-6.06, r=0.65, p<0.04) or by radiographic aggregate tumor mass for all data points identified (slope=0.07+/-0.03, r=0.33, p<0.04) and after correcting for selection bias (slope=1.45+/-0.17, r=0.93, p<0.01). We also identified a significant difference between serum MIS/AMH levels between samples drawn the same day as negative and positive abdominal CT or MRI scans (8.16+/-1.54 vs. 158.7+/-32.2 ng/ml, p<0.0001). CONCLUSIONS: These data indicate a significant direct correlation between serum MIS/AMH levels and both gross and radiographic aggregate tumor mass in GCT patients. Together with the current literature, the present data argue for a more prominent role for serum MIS/AMH in the management of GCTs.

Identification of large-scale characteristic genes of Müllerian inhibiting substance in human ovarian cancer cells.

The purpose of this study was to investigate the large-scale characteristic molecular signature of Müllerian inhibiting substance (MIS) in human ovarian cancer cells through expression genomics. To understand the comprehensive molecular mechanisms by which MIS inhibits ovarian cancer cell growth, we identified the large-scale characteristic molecular changes elicited by MIS in the human ovarian cancer cell line OVCAR-8, using DNA microarray analysis. Combined serial gene expression analysis from 0 to 96 h after MIS treatment of OVCAR-8 cells resulted in 759 genes which showed at least a 2-fold change in overexpression or underexpression compared to non-treatment groups. Of the 759 outlier genes, 498 genes were mapped to known biological cellular processes, and the resultant major pathways included metabolism, signal transduction, cell growth and apoptosis. Among these pathways, 68 genetic elements were dissected as cell cycle-related genes induced by MIS. Although cellular phenotypic changes by MIS were observed after 24 h of treatment, the characteristic large-scale molecular changes were observed from 48 to 96 h of exposure to MIS. This finding may imply that the suppressive role of MIS on ovarian cancer cells could be cumulative in that the metabolic disturbance of MIS is followed by arrest at the G1/S cell cycle checkpoint. We suggest 759 outlier genes comprise the characteristic molecular signature of MIS, which may be responsible for the suppressive effect on OVCAR-8 cells. Although the precise biological mechanisms underlying these outlier genes should be validated, the genetic elements described herein provide promising therapeutic interventions for ovarian cancer.

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.

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.

Müllerian inhibiting substance inhibits an ovarian cancer cell line via ß-catenin interacting protein deregulation of the Wnt signal pathway.

Müllerian inhibiting substance/anti-Müllerian hormone (MIS/AMH) has been suggested as a biotherapeutic agent in gynecological cancers that highly express the MIS/AMH type II receptors (MISRII/AMHRII) but the anticancer mechanisms by which MIS/AMH acts are not fully understood. Our experiments show that MIS/AMH inhibits ovarian cancer by deregulating the Wnt signal pathway via the ß-catenin interacting protein (ICAT). MIS/AMH inhibition of ICAT by small interfering RNAs (siRNA) decreased ICAT driven ovarian cancer cell viability as measured by the methylthiazoltetrazolium assay, reversed cell cycle arrest and annexin V expression and diminished migration by scratch wound assay. Changes in expression of regulatory proteins were shown by western blotting. We determined that MIS/AMH upregulated ICAT in ovarian cancer cell line which caused decreased cell viability, cell cycle arrest and apoptosis. This effect, however, was blocked when ICAT was downregulated by siRNA. The present study demonstrates a role for ICAT in MIS/AMH mediated inhibition of the Wnt signaling pathway in ovarian cancer.

Metformin reduces serum mullerian-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.

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.

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), ß-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.

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.

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.

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.