Gain of OGP, an estrogen-regulated oviduct-specific glycoprotein, is associated with the development of endometrial hyperplasia and endometrial cancer

Loss of HOXA10 causes endometrial hyperplasia progressing to endometrial cancer

Endometrial cancer is the fourth most common malignancy in women and the precursor lesion is endometrial hyperplasia. HOXA10 is a transcription factor that plays key roles in endometrial functions such as the endowment of receptivity, embryo implantation, and trophoblast invasion. Herein, using testicular transgenesis, we developed transgenic mice that expressed a shRNA against HOXA10 and there was a nearly 70% reduction in the expression of HOXA10 in these animals. We observed that downregulation of HOXA10 led to the development of endometrial hyperplasia in the young animals (3 months), and as they aged (>1 year), most animals developed well-differentiated endometrial adenocarcinoma. In the endometrium of animals with reduced HOXA10, there was increased proliferation and elevated levels of ERα and ERβ. In parallel, there was increased expression of Wnt4 and β-Catenin, SOX9, and YAP1. We propose that chronic reduction in HOXA10 expression disrupts multiple pathways in the uterus that aids in the development of endometrial hyperplasia which progresses to endometrial cancer with age.

Which Low-Abundance Proteins are Present in the Human Milieu of Gamete/Embryo Maternal Interaction?

The improvement of the embryo culture media is of high relevance due to its influence on successful implantation rates, pregnancy, neonatal outcomes, and potential effects in adult life. The ideal conditions for embryo development are those naturally occurring in the female reproductive tract, i.e., the oviductal and uterine fluids. To shed light on the differences between chemical and natural media, we performed the first comparative study of the low abundance proteins in plasma, uterine, and oviductal fluid collected, simultaneously, from healthy and fertile women that underwent a salpingectomy. The rationale for this design derives from the fact that high-abundant proteins in these fluids are usually those coming from blood serum and frequently mask the detection of low abundant proteins with a potentially significant role in specific processes related to the embryo–maternal interaction. The proteomic analysis by 1D-nano LC ESI-MSMS detected several proteins in higher amounts in oviductal fluid when compared to uterine and plasma samples (RL3, GSTA1, EZRI, DPYSL3, GARS, HSP90A). Such oviductal fluid proteins could be a target to improve fertilization rates and early embryo development if used in the culture media. In conclusion, this study presents a high-throughput analysis of female reproductive tract fluids and contributes to the knowledge of oviductal and uterine secretome.

Hormonal regulation of oviductal glycoprotein 1 (OVGP1; MUC9) in the rhesus macaque cervix

BACKGROUND

Macaques are outstanding animal models for the development of new contraceptives. In women, progestin-only contraceptives often fail to block ovulation and are believed to act by altering cervix physiology. Herein, we assessed oviductal glycoprotein 1 (OVGP1) in the macaque cervix as a marker for progestogen action.

MATERIALS

Rhesus macaques were treated with estradiol (E₂ ), E₂ plus progesterone (P), and E₂ plus levonorgestrel (LNG), a contraceptive progestin. Samples consisted of archived blocks of midcervix mucosa (epithelium and lamina propria) and fresh epithelial cells collected non-invasively by cytobrush. OVGP1 was assayed by quantitative real-time PCR and localized by immunocytochemistry.

RESULTS

OVGP1 transcript was maximal after E₂ and reduced after treatment with E₂  + P (P < .05). LNG also reduced OVGP1 expression (P < .05). OVGP1-specific staining localized to epithelial cells, and transcript was quantifiable in cytobrush collected samples.

CONCLUSIONS

OVGP1 expression in cytobrush samples of macaque cervix provides a non-invasive indicator of contraceptive progestin action.

Extra-oviductal expression of oviductal glycoprotein 1 in mouse: Detection in testis, epididymis and ovary

Oviductal glycoprotein 1 (OVGP1), also called oviductin, is an oviduct-specific protein and is suggested to play a role in fertilization. Traditionally, Ovgp1 has been shown to be exclusively expressed by the oviduct; however, recent studies have demonstrated its expression in some cancers. This observation led us to hypothesize that Ovgp1 might have some extra-oviductal expression. In the current study, we evaluated the mRNA and protein expression of Ovgp1 in normal reproductive tissues of male and female mice. For the first time, we demonstrate that beyond the oviduct, Ovgp1 mRNA is expressed in the testis, epididymis and ovary, but not in the uterus, cervix, vagina, breast, seminal vesicles and prostate gland. In the testis, Ovgp1 mRNA was localized in the cells at the base of seminiferous tubules (most likely, Sertoli cells), while the protein was detected in the round and elongating spermatids. In the epididymis, Ovgp1 transcripts were localized in epididymal epithelium of the caput but not the corpus and cauda; OVGP1 protein was, however, not detected in any of the segments but was present in the epididymal sperm. In the ovary, Ovgp1 transcripts and protein were detected in the surface epithelium, granulosa cells of the preantral and the antral follicles and corpus luteum. In both, the ovary and oviduct, the expression of Ovgp1 was found to be higher at estrus stage than at diestrus stage. To the best of our knowledge, this is the first study demonstrating the extra-oviductal expression of Ovgp1. Our data suggests that, beyond fertilization, Ovgp1 might have specific roles in gonadal physiology. [Laheri S, Modi D and Bhatt P 2017 Extra-oviductal expression of oviductal.

Prognostic biomarkers in endometrial and ovarian carcinoma

This article reviews the main prognostic and predictive biomarkers of endometrial (EC) and ovarian carcinoma (OC). In EC, prognosis still relies on conventional pathological features such as histological type and grade, as well as myometrial or lymphovascular space invasion. Estrogen receptor, p53, Ki-67, and ploidy analysis are the most promising biomarkers among a long list of molecules that have been proposed. Also, a number of putative predictive biomarkers have been proposed in molecular targeted therapy. In OC, prognosis is predominantly dependent on disease stage at diagnosis and the extent of residual disease at primary operation. Diagnostic markers which aid in establishing histological type in OC are available. However, not a single universally accepted predictive or prognostic marker exists to date. Targeted therapy has been growingly focused at in recent years, in view of the frequent development of chemoresistance at recurrent disease. The present review emphasizes the crucial role of correct pathological classification and stringent selection criteria of the material studied as basis for any evaluation of biological markers. It further emphasizes the promise of targeted therapy in EC and OC, while simultaneously highlighting the difficulties remaining before this can become standard of care.

Technical challenges and limitations of current mouse models of ovarian cancer

The development of genetically engineered models (GEM) of epithelial ovarian cancer (EOC) has been very successful, with well validated models representing high grade and low grade serous adenocarcinomas and endometrioid carcinoma (EC). Most of these models were developed using technologies intended to target the ovarian surface epithelium (OSE), the cell type long believed to be the origin of EOC. More recent evidence has highlighted what is likely a more prevalent role of the secretory cell of the fallopian tube in the ontogeny of EOC, however none of the GEM of EOC have demonstrated successful targeting of this important cell type.

The precise technologies exploited to develop the existing GEM of EOC are varied and carry with them advantages and disadvantages. The use of tissue specific promoters to model disease has been very successful, but the lack of any truly specific OSE or oviductal secretory cell promoters makes the outcomes of these models quite unpredictable. Effecting genetic change by the administration of adenoviral vectors expressing Cre recombinase may alleviate the perceived need for tissue specific promoters, however the efficiencies of infection of different cell types is subject to numerous biological parameters that may lead to preferential targeting of certain cell populations.

One important future avenue of GEM of EOC is the evaluation of the role of genetic modifiers. We have found that genetic background can lead to contrasting phenotypes in one model of ovarian cancer, and data from other laboratories have also hinted that the exact genetic background of the model may influence the resulting phenotype. The different genetic backgrounds may modify the biology of the tumors in a manner that will be relevant to human disease, but they may also be modifying parameters which impact the response of the host to the technologies employed to develop the model.

MALDI Imaging Mass Spectrometry (MALDI-IMS)-application of spatial proteomics for ovarian cancer classification and diagnosis

MALDI imaging mass spectrometry (MALDI-IMS) allows acquisition of mass data for metabolites, lipids, peptides and proteins directly from tissue sections. IMS is typically performed either as a multiple spot profiling experiment to generate tissue specific mass profiles, or a high resolution imaging experiment where relative spatial abundance for potentially hundreds of analytes across virtually any tissue section can be measured. Crucially, imaging can be achieved without prior knowledge of tissue composition and without the use of antibodies. In effect MALDI-IMS allows generation of molecular data which complement and expand upon the information provided by histology including immuno-histochemistry, making its application valuable to both cancer biomarker research and diagnostics. The current state of MALDI-IMS, key biological applications to ovarian cancer research and practical considerations for analysis of peptides and proteins on ovarian tissue are presented in this review.

Oviductal glycoprotein (OVGP1, MUC9): a differentiation-based mucin present in serum of women with ovarian cancer

INTRODUCTION

Epithelial ovarian carcinomas are highly lethal because most are detected at late stages. A previous immunohistochemical analysis showed that oviductal glycoprotein 1 (OVGP1), a secretory product of the oviductal epithelium under estrogen dominance, is produced predominantly by borderline and low-grade malignant epithelial ovarian tumors. In the present study, we investigated OVGP1 as a possible serum marker for the detection of ovarian cancer.

METHODS

We generated a highly specific monoclonal antibody, clone 7E10, to human OVGP1. Using 7E10 and a polyclonal antibody, a sandwich enzyme-linked immunosorbent assay was developed to assay OVGP1 levels in 135 normal sera, and sera from 21 benign tumors, 12 borderline tumors, and 87 ovarian cancers (18, grade 1-2 serous; 44, grade 3 serous; 10, mucinous; 10, clear cell; and 5, endometrioid).

RESULTS

Using a 95% confidence interval cutoff from the mean of normal postmenopausal sera, median OVGP1 levels were elevated in the sera from 75% of the women with borderline tumors and 80% of the women with mucinous, 60% with clear cell, 59% with grade 1 and 2 serous, 22% with grade 3 serous, and 0% with endometrioid carcinomas. By stage, OVGP1 levels were highest in the sera from the borderline tumors, stage I and II serous carcinomas, and mucinous carcinomas. OVGP1 levels varied independently of cancer antigen 125 (CA125).

CONCLUSIONS

Increases in OVGP1 serum levels vary with ovarian tumor histotypes and stages. Being differentiation based, OVGP1 seems to detect a different spectrum of ovarian epithelial cancers than other markers and thus should be a useful adjunct for more accurate detection, particularly of early serous ovarian cancers and mucinous carcinomas, which tend to lack increased CA125.

Oviduct-specific glycoprotein is a molecular marker for invasion in endometrial tumorigenesis identified using a relevant mouse model

The light microscopic distinction between complex atypical hyperplasia (CAH) and invasive endometrioid carcinoma (UEC) on endometrial sampling is problematic and often has significant clinical implications. Using mouse models of endometrial tumorigenesis based on two of the most common molecular alterations found in primary human UEC we sought to characterize the transition from CAH to carcinoma to identify clinically useful biomarkers. We used the previously described Pten(+/-); Mlh1(-/-) mouse model. DNA was isolated from microdissected lesions (CAH and carcinoma) and analyzed for LOH and mutations of Pten and additional candidate genes. To identify novel candidate genes associated with invasion, global gene expression profiles were compared from uteri with extensive CAH and carcinoma. The majority of CAHs and carcinomas, arising in this model showed biallelic inactivation of Pten mediated through LOH or intragenic mutation of the wild-type allele suggesting that complete loss of Pten is insufficient for the development of carcinoma. The global gene expression studies detected increased expression of oviduct-specific glycoprotein (OGP) in carcinoma as compared with CAHs. This finding was validated using immunohistochemical staining in a collection of primary human UECs and CAHs. Our studies identify a molecular marker for invasive endometrial cancer that may have clinical significance, and highlight the usefulness of this mouse model in not only understanding the genetic underpinnings of endometrial carcinoma, but as a tool to develop clinically relevant biomarkers.

Endometriosis is associated with progesterone resistance in the baboon (Papio anubis) oviduct: evidence based on the localization of oviductal glycoprotein 1 (OVGP1)

Endometriosis has been associated with a reduced response to progesterone in both the eutopic and ectopic endometrium. In this study we evaluated OVGP1 and steroid receptor expression in oviducts of baboons with endometriosis during the midsecretory phase and determined whether progesterone resistance associated with endometriosis also occurs in the oviduct. Oviducts obtained during the window of uterine receptivity (Day 10 postovulation [PO]) from animals with induced and spontaneous disease were compared to control animals during the proliferative stage and in the implantation window as well as animals treated with the progesterone receptor (PGR) antagonist ZK 137.299 (ZK). OVGP1 was significantly higher in animals with endometriosis compared with Day 10 PO controls and was similar to that seen in the late proliferative phase and in ZK-treated animals. Baboons with spontaneous endometriosis also showed a similar persistence of OVGP1, which was correlated with the maintenance of estrogen receptor 1 (ESR1) in the epithelial cells of animals with endometriosis. However, epithelial cell height and the percentage of ciliation were not affected by endometriosis. These data imply that the normal antagonism of progesterone on ESR and OVGP1, which results in their downregulation during the window of implantation, is absent in animals with endometriosis. This was confirmed further when the action of PGR was antagonized in animals without disease, which also resulted in the persistence of ESR1 and OVGP1. These studies suggest that an aberrant oviductal environment may be an additive factor that contributes to endometriosis-associated infertility.

Immunohistochemical markers in endometrial hyperplasia: is there a panel with promise? A review

OBJECTIVE

Despite advances in defining the biology of endometrial carcinomas, there has been little progress in determining markers that distinguish preinvasive endometrial proliferations. The goal of this literature review was to identify studies on endometrial hyperplasia (EH) that describe markers with potential to predict response to progestin therapy or potential for progression to invasive disease.

METHODS

Articles published between January 2000 and October 2006 were identified using the key words endometrial hyperplasia and progesterone receptor or estrogen receptor or biologic marker or immunohistochemistry/immunohistochemical. Articles that reported immunohistochemical studies on specimens of human EH +/-endometrioid endometrial carcinoma with a normal comparison group were included. Only those who reported hyperplasia with atypia separately from nonatypical hyperplasia and with a sample size greater than 10 specimens for the sum of complex and atypical samples were included.

RESULTS

A total of 289 abstracts were reviewed and 150 articles potentially met inclusion criteria. Of these, 123 described immunohistochemical studies on human EH specimens. Only 46 met all criteria for analysis of 61 different markers.

CONCLUSIONS

PTEN seems to have the greatest potential for diagnostic utility in EH, perhaps in combination with Bcl-2 and Bax. However, more uniform and rigorous studies are required to confirm these and additional markers' utility diagnostically in a diagnostic panel. As a major clinical priority is to determine which lesions can be treated medically and which require surgical intervention, focusing future studies on markers that distinguish response to hormone therapy or are involved in hormone regulation, will be important future considerations.

Identification of cellular isoform of oviduct-specific glycoprotein: role in oviduct tissue remodeling?

The oviduct is known to secrete mucins (MUC1 and MUC9) under the influence of ovarian steroids. The secreted form of MUC1 binds gametes in the oviduct, whereas the cellular form seen in breast cancers has been implicated in cell adhesion and morphogenesis. The secreted MUC9 or oviduct-specific glycoprotein (OGP), in addition to being a mucin, belongs to family 18 glycosylhydrolases and is known to bind gametes and embryos in the oviduct. Studies in our laboratory have identified non-muscle myosin IIA (involved in cell shape, polarity, and morphogenesis) as the protein partner to OGP in gametes. In view of the crucial role of the cortical cytoskeleton in the selective internalization of tight junctions (TJs) /adherent junctions (AJs) or apical junctional complex (AJC) in simple epithelial cells during tissue remodeling, the present study has been undertaken to evaluate the existence of a cellular form of OGP in oviductal tissue, which itself undergoes cyclic tissue remodeling. In silico analysis of the deduced amino-acid sequence of OGP has revealed the presence of several conserved motifs; these imply that OGP is a component of multi-protein complexes such as TJs. Corroborative immunoelectron-microscopic analysis in peri-ovulatory oviduct epithelia in the bonnet monkey has revealed the presence of OGP at the TJ. Co-localization studies of OGP and cadherin demonstrate that, whereas OGP is localized at the tonofilaments of the TJs, cadherin is localized at the intercellular space of the AJ. The possible role of OGP in oviductal tissue remodeling is discussed in light of the present findings and those reported in the literature.

Immunoneutralization of endometrial monoclonal nonspecific suppressor factor beta (MNSFβ) inhibits mouse embryo implantation in vivo

Successful embryo implantation and pregnancy in mammals depends on the establishment of immune tolerance between the maternal immune system and fetal cells. Monoclonal nonspecific suppressor factor beta (MNSFbeta), a cytokine produced by suppressor T cells in various tissues, possesses an antigen-nonspecific immune-suppressive function, and may be involved in the regulation of the uterine immune response during embryo implantation. In this study, anti-MNSFbeta IgG administered directly into the uterine lumen, significantly inhibited mouse embryo implantation in a dose-dependent manner in vivo, and this effect was reversed by co-administration of recombinant MNSFbeta. The effects of anti-MNSFbeta IgG on the gene pattern profiles in mouse uterine tissues were examined by cDNA microarray and several changes were confirmed by real-time PCR. Anti-MNSFbeta IgG caused up-regulation (> or = 2-fold) of 71 known genes and 17 unknown genes, and decreased expression (> or = 2-fold) of 74 known genes and 43 unknown genes, including several genes previously associated with embryo implantation or fetal development. Most of the known genes are involved in immune regulation, cell cycle/proliferation, cell differentiation/apoptosis, and lipid/glucose metabolism. These results demonstrate that MNSFbeta plays critical roles during the early pregnancy via multiple pathways.

Gene expression analysis reveals a signature of estrogen receptor activation upon loss of Pten in a mouse model of endometrial cancer

Loss of PTEN is the earliest detectable genetic lesion in the endometrioid subtype of endometrial cancer (EEC), a tumor thought to be associated with an increase in unopposed estrogen activity. Pten(+/-) mice develop endometrial neoplastic lesions with full penetrance, despite having normal estrogen levels. We have utilized oligonucleotide arrays to identify the alterations in gene expression patterns associated with loss of Pten and consequent neoplastic transformation of the endometrium. We show that 487 and 330 genes are substantially up- and downregulated, respectively, in Pten(+/-) mice. Several genes whose expression levels are impacted by loss of Pten are associated with pathways and functions that are relevant to the transformation and progression processes. Strikingly, we found that the expression levels of over 100 genes known to be regulated by estrogen receptor alpha (ERalpha) are also altered in the neoplastic uterus from Pten(+/-) mice, thus mimicking a hyperestrogenic environment. These results provide in vivo evidence supporting the hypothesis that loss of Pten and subsequent Akt activation result in the activation of several ERalpha-dependent pathways that, mimicking increased estrogen signaling, may play a pivotal role in the neoplastic process.