Oviductal Epithelium Research Articles

TP53 loss initiates chromosomal instability in fallopian tube epithelial cells.

ABSTRACTHigh-grade serous ovarian cancer (HGSOC) originates in the fallopian tube epithelium and is characterized by ubiquitous TP53 mutation and extensive chromosomal instability (CIN). However, direct causes of CIN, such as mutations in DNA replication and mitosis genes, are rare in HGSOC. We therefore asked whether oncogenic mutations that are common in HGSOC can indirectly drive CIN in non-transformed human fallopian tube epithelial cells. To model homologous recombination deficient HGSOC, we sequentially mutated TP53 and BRCA1 then overexpressed MYC. Loss of p53 function alone was sufficient to drive the emergence of subclonal karyotype alterations. TP53 mutation also led to global gene expression changes, influencing modules involved in cell cycle commitment, DNA replication, G2/M checkpoint control and mitotic spindle function. Both transcriptional deregulation and karyotype diversity were exacerbated by loss of BRCA1 function, with whole-genome doubling events observed in independent p53/BRCA1-deficient lineages. Thus, our observations indicate that loss of the key tumour suppressor TP53 is sufficient to deregulate multiple cell cycle control networks and thereby initiate CIN in pre-malignant fallopian tube epithelial cells. This article has an associated First Person interview with the first author of the paper.

Ovulation sources coagulation protease cascade and hepatocyte growth factor to support physiological growth and malignant transformation

• Ovulatory follicular fluid exerts a long-lasting transformation activity covering throughout the ovulation cycle. • The ovulation injury-coagulation proteases-hepatocyte growth factor (HGF) cascade is responsible for the sustained activity. • Ovulation sources HGF into the peritoneal cavity, then into the blood circulation. • This coagulation-HGF cascade promotes the transformation of fallopian tube epithelial cells and ovarian cancer cells. • Physiologically, it promotes the growth of the corpus luteum and injured epithelium after ovulation. The fallopian tube fimbrial epithelium, which is exposed to the follicular fluid (FF) contents of ovulation, is regarded as the main origin of ovarian high-grade serous carcinoma. Previously, we found that growth factors in FF, such as IGF2, are responsible for the malignant transformation of fallopian tube epithelium. However, ovulation is a monthly transient event, whereas carcinogenesis requires continuous, long-term exposure. Here, we found the transformation activity of FF sustained for more than 30 days after drainage into the peritoneal fluid (PF). Hepatocyte growth factor (HGF), activated through the ovulation injury-tissue factor–thrombin–HGF activator (HGFA)–HGF cleavage cascade confers a sustained transformation activity to fallopian tube epithelium, high-grade serous carcinoma. Physiologically, the high reserve of the coagulation-HGF cascade sources a sustained level of HGF in PF, then to the blood circulation. This HGF axis promotes the growth of the corpus luteum and repair of tissue injury after ovulation.

Computerized morphometry analysis of epithelial fimbriae nuclear symmetry in BRCA carriers may identify patients at risk for developing ovarian cancer.

Serous ovarian tumors may originate in epithelial cells of the fallopian tubes. Computerized morphometry was able to find significant alterations in the fallopian tube epithelium of healthy BRCA carriers. The purpose of this study was to identify a subgroup of BRCA carriers that may be at risk of developing serous ovarian cancer by evaluation of the epithelial nuclear symmetry in the fallopian tubes. Four groups of patients were analyzed; healthy patients, ovarian cancer patients, BRCA carriers, and BRCA noncarriers. All fallopian tubes appeared normal by H&E examination. The ImageProPlus software was used to assess the nuclear symmetry of 65 fimbriae epithelium cells and an artificial neural network algorithm aided in detecting a subpopulation among fimbriae of healthy BRCA carriers at risk for ovarian cancer. Significant differences were found between healthy patients and ovarian cancer patients, and between BRCA carriers and noncarriers. The algorithm was able to accurately predict BRCA carriers with associated ovarian cancer based on fallopian tube nuclear symmetry characteristics. These results reinforce the hypothesis that fimbriae epithelial cells of BRCA carriers may undergo early-stage changes that could predict the risk of progression toward malignancy.

Amino Acids and the Early Mammalian Embryo: Origin, Fate, Function and Life-Long Legacy.

Amino acids are now recognised as having multiple cellular functions in addition to their traditional role as constituents of proteins. This is well-illustrated in the early mammalian embryo where amino acids are now known to be involved in intermediary metabolism, as energy substrates, in signal transduction, osmoregulation and as intermediaries in numerous pathways which involve nitrogen metabolism, e.g., the biosynthesis of purines, pyrimidines, creatine and glutathione. The amino acid derivative S-adenosylmethionine has emerged as a universal methylating agent with a fundamental role in epigenetic regulation. Amino acids are now added routinely to preimplantation embryo culture media. This review examines the routes by which amino acids are supplied to the early embryo, focusing on the role of the oviduct epithelium, followed by an outline of their general fate and function within the embryo. Functions specific to individual amino acids are then considered. The importance of amino acids during the preimplantation period for maternal health and that of the conceptus long term, which has come from the developmental origins of health and disease concept of David Barker, is discussed and the review concludes by considering the potential utility of amino acid profiles as diagnostic of embryo health.

Primary prevention of ovarian cancer: a patient decision aid for opportunistic salpingectomy

The discovery of the fallopian tube epithelium as the origin of high-grade serous ovarian cancer has brought a new option for ovarian cancer prevention. The fallopian tubes have no known function after completion of childbearing and can be removed to reduce the lifetime risk of ovarian cancer. Although the lifetime risk in the general population does not justify preventive surgery in itself, salpingectomy can be performed during abdominal surgery for other indications, also known as an opportunistic salpingectomy. The popularity of opportunistic salpingectomy is increasing worldwide; however, the variation between gynecologists and hospitals in their advice on opportunistic salpingectomy occurs because of the remaining uncertainty of evidence. Therefore, whether a woman can make her own decision depends on the hospital or gynecologist she visits. We aimed to lower this practice variation by providing standardized and unbiased counseling material. We aimed to develop and test a patient decision aid for opportunistic salpingectomy in women undergoing pelvic gynecologic surgery to either retain the ovaries or opt for sterilization. We followed a systematic development process based on the International Patient Decision Aid Standards. Data were collected between June 2019 and June 2020, using both qualitative and quantitative methods. The development process that occurred in collaboration with patients and healthcare professionals was overseen by a multidisciplinary steering group and was divided into 4 phases: (1) assessment of decisional needs using individual telephone interviews and questionnaires; (2) development of content and format based on decisional needs, current literature, and guidelines; (3) alpha testing and the first revision round; and (4) alpha testing and the second revision round. An outline of the patient decision aid was developed on the basis of decisional needs, current literature, and guidelines. It became clear that the decision aid should consist of 2 separate paths: one with information specifically for salpingectomy in addition to abdominal surgery and one for salpingectomy as a sterilization method. Both paths contained information on the anatomy and function of ovaries and fallopian tubes, risk reduction of ovarian cancer, and potential benefits and risks of opportunistic salpingectomy. Moreover, the sterilization path contains information on various sterilization methods and risks of unwanted pregnancy. The patient decision aid was developed as an online tool that includes information chapters, a knowledge quiz, consideration statements, and a summary detailing the patient's preferences and considerations. Adjustments were made following alpha testing round 1. The improved patient decision aid was subjected to usability tests (alpha testing round 2), in which it scored an "excellent" in tests with patients and a "good" in tests with gynecologists. Furthermore, our patient decision aid met the requirements of 45 of 49 applicable items from the International Patient Decision Aid Standards criteria. In collaboration with patients and healthcare professionals, a patient decision aid was developed on opportunistic salpingectomy and salpingectomy as a sterilization method. Both patients and gynecologists believed it is a useful tool that supports patients in making an informed decision whether to undergo an opportunistic salpingectomy and supports the counseling process by gynecologists.

Impact of porcine follicular fluid during folliculogenesis as a supplement on the primary cell culture of oviductal epithelial cells

The impact of varying concentrations of porcine follicular fluid (pFF) derived from three ovarian follicle types and produced during folliculogenesis on porcine oviductal epithelial cell (pOEC) culture was studied for 24 h using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Cells treated with pFF at a protein concentration of 500 µg/mL (from small- and large-sized ovarian follicles) and 600 µg/mL (from medium-sized ovarian follicles) showed the highest viability, which was significantly different from that observed in the control group (p<0.05) and not significantly higher than that observed in the positive control group.This study demonstrated that the impact of pFF on pOECs can be used as a model for biotechnological studies. Further, the study showed that instead of costly fetal calf serum, pFF produced during folliculogenesis can be used as a supplement in culture media to promote porcine oviductal epithelium cell growth and development.

Progestin significantly inhibits carcinogenesis in the mogp-TAg mouse model of fallopian tube cancer

<h3>Objectives:</h3> Recent studies suggest the fallopian tube epithelium (FTE) harbors the precursor for high grade ovarian cancer (HGSC), creating opportunities for targeting the FTE for ovarian cancer prevention. Preclinical evidence supports progestins as ovarian cancer preventives, but the effect of progestins on the FTE has not been well characterized. <i>in vitro</i> and primate models suggest that progestins clear genetically damaged cells in the ovarian epithelium and endometrium by activating molecular pathway such as apoptosis. The mogp-TAg transgenic mouse develops neoplastic lesions such as p53 signatures and serous tubal intraepithelial carcinoma (STIC) in the fallopian tube (FT) in a similar manner to that described in human fallopian and ovarian cancers. In this study, we investigated the inhibitory effects of the progestin-Depo-medroxyprogesterone acetate (DMPA) on FT carcinogenesis in the mogp-TAg mouse. <h3>Methods:</h3> Mogp-TAg mice (10 per group) at 5 weeks of age were injected with vehicle or the progestin Depo-medroxyprogesterone acetate-DMPA (1mg/mouse). The mice were euthanized at 8 and 12 weeks of age and the reproductive tract was removed. H&E stained sections were used to histologically and pathologically characterize the FTs following treatment. In addition, immunohistochemistry and immunofluorescence were used to characterize lesions and the cell death pathway. <h3>Results:</h3> There was an increase in the number of FT epithelial and stromal p53 positive cells from 5 to 12 weeks of age in the vehicle treated mice. Histologically, the FT of the vehicle treated mice developed adenocarcinoma and/or epithelial/smooth muscle hyperplasia at 8 and 12 weeks of age. Compared to the vehicle-treated mice, the FT of the DMPA treated mice were significantly smaller at 8 weeks (p<0.005) and 12 weeks (p<0.0005) of age. In addition, there was normal distribution of ciliated cells, less nuclear pleomorphism and epithelial tufting, and a significantly lower proliferative index (Ki67) (p=0.001) in 8 week DMPA treated mice compared to vehicle. Accumulation of p53 in the FT was significantly reduced in DMPA(p<0.000005) treated mice at 8 weeks compared to vehicle. There was significantly more cleaved caspase-3 in the FT of the DMPA-treated group compared to the vehicle group. <h3>Conclusions:</h3> DMPA treatments significantly reduced the tumor burden and aberrant p53 expression in the FT of mice compared to vehicle treated animals. Our data support the hypothesis that progestins have a cytocidal effect, clearing genetically damaged cells from the fallopian tube potentially via apoptosis. These data provide evidence supporting the hypothesis that progestin may be used for prevention of ovarian cancer.

Sub-millimeter endoscope demonstrates feasibility of in vivo reflectance imaging, fluorescence imaging, and cell collection in the fallopian tubes.

.Significance: Most cases of high-grade serous ovarian carcinoma originate as serous tubal intraepithelial carcinoma (STIC) lesions in the fallopian tube epithelium (FTE), enabling early endoscopic detection.Aim: The cell-acquiring fallopian endoscope (CAFE) was built to meet requirements for locating potentially pathological tissue indicated by an alteration in autofluorescence or presence of a targeted fluorophore. A channel was included for directed scrape biopsy of cells from regions of interest.Approach: Imaging resolution and fluorescence sensitivity were measured using a standard resolution target and fluorescence standards, respectively. A prototype was tested in ex vivo tissue, and collected cells were counted and processed.Results: Measured imaging resolution was at a 5-mm distance, and full field of view was in air. Reflectance and fluorescence images in ex vivo porcine reproductive tracts were captured, and fit through human tracts was verified. Hemocytometry counts showed that on the order of per scrape biopsy could be collected from ex vivo porcine tissue.Conclusions: All requirements for viewing STIC in the FTE were met, and collected cell counts exceeded input requirements for relevant analyses. Our benchtop findings suggest the potential utility of the CAFE device for in vivo imaging and cell collection in future clinical trials.

Abstract 744: Progesterone receptors promote quiescence &amp; ovarian cancer cell phenotypes via modulation of DREAM in p53-mutant fallopian tube models

Abstract The ability of ovarian steroids to modulate ovarian cancer (OC) risk remains controversial. High grade serous ovarian carcinoma (HGSC), the most aggressive OC subtype, contains abundant estrogen (ER; 76%) and progesterone (PR; 35%) receptors. Progesterone is thought to be a primarily protective factor that reduces OC risk but the relevance of PR actions in HGSC is unknown. Our IHC analyses of human clinical tissues showed robust expression of total and activated phospho-S294 PR within serous tubal intraepithelial carcinomas (STIC), precursor HGSC lesions of fallopian tube epithelia (FTE), suggesting a role for PR signaling in early disease. To explore the molecular mechanisms of PR isoform actions, p53-dominant negative mutant FTE lines expressing the PR-A or PR-B isoform were created. Progestin treatment (R5020 or progesterone) of these models induced spheroid formation and reaggregation, transwell migration and collagen invasion. RNAseq analyses revealed enrichment of cell cycle progression pathways; in particular, the gene targets of the repressive DREAM complex that drives quiescent cell fate. Progestins induced inhibition of proliferation (decreased Ki67; decreased BrdU; increased B-galactosidase) and accumulation of cells in G0/G1 that was reversed following growth factor stimulation. Subsequent immunoprecipitation of DREAM (G0) and B-MYB/MMB complexes (G1/S) confirmed that PR-driven changes in cell fate occur via regulation of the DREAM complex. PR activation enhanced DREAM and suppressed B-MYB/MMB complex formation. PR also induced transcriptional regulation of DREAM/B-MYB/MMB genes (LIN9, MYBL2, DYRK1A, FOXM1) via promoter recruitment and mRNA regulation. Interestingly, DREAM complexes contained PR and PR was co-recruited to DREAM binding sites within DREAM target promoters, along with the DREAM complex proteins p130 and E2F4. The relevance of the quiescent state to early OC phenotypes was examined through the disruption of DREAM/DYRK1s by pharmacological inhibition (harmine) , HPV E6/E7 expression or the depletion of DYRK1A/B kinases that promote DREAM complex formation. These manipulations blocked progestin-induced cell cycle arrest and attenuated PR-driven gene expression and associated OC phenotypes. Our results reveal that activated PRs support quiescence and pro-survival/pro-dissemination cell behaviors that may contribute to early HGSC progression. Taken together, our data suggest an alternative perspective on the tenant that progesterone always confers protection against OC. STICs can reside undetected for decades prior to invasive disease. Our studies reveal clinical opportunities to prevent the ultimate development of HGSC by targeting activated PRs, DREAM complexes, and/or DYRKs (Supported by the Minnesota Ovarian Cancer Alliance to LJM and CAL). Citation Format: Laura J. Mauro, Megan I. Seibel, Caroline H. Diep, Angela Spartz, Carlos Perez Kerkvliet, Hari Singhal, Elizabeth M. Swisher, Lauren E. Schwartz, Ronny Drapkin, Siddharth Saini, Fatmata Seesay, Larisa Litovchick, Carol A. Lange. Progesterone receptors promote quiescence &amp; ovarian cancer cell phenotypes via modulation of DREAM in p53-mutant fallopian tube models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 744.

Expression of nuclear progesterone receptor, progesterone receptor membrane components 1 and 2 and prostaglandin-endoperoxide synthase 2 in the endometrium and oviduct of spontaneously ovulating cats

Although ovulations not followed by pregnancy occur regularly in cats, differences in endometrial function between cats in the luteal and non-luteal phase have not been studied so far. Progesterone exerts its effects through a nuclear progesterone receptor (PGR) and via cell-membrane bound receptors referred to as progesterone receptor membrane component (PGRMC) 1 and 2. Progesterone receptor expression is regulated by gonadal steroid hormones and therefore may change throughout the oestrous cycle. Protein expression of PGR, PGRMC-1 and 2 and prostaglandin-endoperoxide synthase 2 (PTGS2) was analysed in the endometrium and oviduct of non-pregnant female cats in the follicular (n = 8) and luteal phase (n = 9). We hypothesized that the presence of corpora lutea (CL) is associated with downregulation of progesterone receptors and PTGS2. Cells of the luminal endometrial epithelium, endometrial stroma and oviductal epithelium were assessed by immunohistochemistry. The PGR protein expression was more pronounced in the endometrial epithelium than stroma (p < 0.001) and less pronounced in cats with a CL than without CL (p < 0.001) but did not differ between groups in the oviduct. The PTGS2 was localized only in the endometrial and oviductal epithelium and its expression was reduced in cats with CL (p = 0.001). In the endometrial epithelium, PGRMC-1 expression was reduced in cats with CL (p < 0.05). Expression of PGRMC-2 was highest in the endometrial epithelium and lowest in the endometrial stroma (p = 0.01) but did not differ between cats with and without CL. In conclusion, progesterone receptor and PTGS2 downregulation in the female cat closely resembles findings in other spontaneously ovulating domestic animal species.

Cystic ovary disease impairs transport speed, smooth muscle contraction, and epithelial ion transport in the bovine oviduct.

Cystic ovary disease (COD) is a common cause of bovine infertility but the impact of this disease on the oviduct is unknown. The aim of this study was to analyze the effects of COD on particle transport speed (PTS), ciliary beat frequency, myosalpinx contraction, and epithelial ion transport. Oviducts were obtained from cows affected by COD and compared with those of healthy, mid-diestrus cows. PTS and CBF were examined using live-cell imaging. Smooth muscle contraction and epithelial ion transport were investigated using organ baths and Ussing chambers. Our results showed that muscarinic receptors are involved in cholinergic signaling in the oviduct and that forskolin-induced cyclic AMP production is involved in active ion transport in the oviductal epithelium. Oviducts from cows with luteal cysts revealed significantly decreased PTS (p = 0.02). Further to that, in the oviducts of COD cows, the cholinergic regulation of smooth muscle contractions and active epithelial ion transport were significantly diminished (p < 0.0001). These results imply that in COD cows, oviductal transport is compromised by decreased fluid flow speed and reduced cholinergic regulation of smooth muscle contraction and ion transport. This knowledge contributes to a more comprehensive understanding of COD supporting the development of novel therapeutic concepts for infertility treatment.

Evidence of haptoglobin in the porcine female genital tract during oestrous cycle and its effect on in vitro embryo production

Recent evidence supports involvement of the acute phase protein haptoglobin in numerous events during mammalian reproduction. The present study represents an in-depth investigation of haptoglobin expression and secretion in the porcine oviduct and uterus, and assesses its effect on porcine in vitro embryo production. A systematic study was made of sows in different oestrous stages: late follicular, early luteal and late luteal stages. Relative haptoglobin mRNA abundance was quantified by RT-qPCR. In addition, expression of the protein was analysed by immunohistochemistry and the results were complemented by Western-blot and proteomic analyses of the oviductal and uterine fluids. In vitro porcine fertilization and embryo culture were carried out in the presence of haptoglobin. The results indicate that haptoglobin mRNA expression in the porcine oviduct and uterus is most abundant during the late luteal stage of the oestrous cycle. By means of Western blot and proteomic analyses haptoglobin presence was demonstrated in the oviduct epithelium and in the oviductal and uterine fluids in different stages of the oestrous cycle. The addition of haptoglobin during gamete co-incubation had no effect on sperm penetration, monospermy or efficiency rates; however, compared with the control group, blastocyst development was significantly improved when haptoglobin was present (haptoglobin: 64.50% vs. control: 37.83%; p < 0.05). In conclusion, the presence of haptoglobin in the oviduct and uterus of sows at different stages of the oestrous cycle suggests that it plays an important role in the reproduction process. The addition of haptoglobin during in vitro embryo production improved the blastocyst rates.

Identification of signal transduction pathway activity with potential clinical target in high-grade serous ovarian and tubal carcinoma.

e17541 Background: High-grade serous carcinoma (HGSC) is the most common subtype of epithelial ovarian and tubal cancer. It has a high mortality rate, even after successful first-line treatment with debulking surgery and chemotherapy. Although therapeutic options for targeted therapy are rapidly expanding, identification of patients who respond to these therapies remains a challenge. In recognition of the importance of the functional phenotype of cancer cells, Verhaegh et al. (Cancer Res 2014) developed assays to measure functional activity of signal transduction pathways (STPs) based on mRNA expression levels of pathway-specific target genes. In this study, we aimed to identify HGSCs with STP activity with potential clinical target by comparing their activity assessment with STP activity in normal Fallopian tube epithelium (FTE), the tissue of origin of most HGSCs. Methods: We included 67 primary tumor samples taken prior to start of chemotherapy of postmenopausal patients diagnosed with advanced stage HGSC and 8 morphologically normal FTE samples of healthy postmenopausal women. Using OncoSignal pathway assays, we assessed functional pathway activity of the androgen receptor (AR), estrogen receptor (ER), PI3K, Hedgehog, TGF-𝛽 and Wnt pathways. Differences in STP activity between groups were compared with Mann-Whitney U tests. Cut-off value for aberrant STP activity was defined as two standard deviations above the mean value of STP activity measured in FTE samples. Results: In the HGSC group we observed lower median ER (p &lt; 0.001) and Wnt (p = 0.046) pathway activity and higher median PI3K (p = 0.025) and TGF-𝛽 pathway (p = 0.030) activity as compared to the normal FTE group. In individual HGSC samples, aberrant activity was identified for the AR (n = 14), PI3K (n = 16), Hedgehog (n = 4), TGF-𝛽 (n = 36) and Wnt (n = 10) pathways. Frequently observed combinations of aberrant STP activity were AR/TGF-𝛽 (n = 8), TGF-𝛽/Wnt (n = 6) and PI3K/Hedgehog (n = 3). In total, we identified at least one STP with potential clinical target in 52 of the 67 HGSC samples. Conclusions: Our analysis enabled the identification of STP activity with potential clinical target in 78% of the analyzed HGSC samples. Differentiation between normal and aberrant STP activity could have clinical utility in the selection of HGSC patients for targeted therapy.

Dynamics of apoptosis-related gene expression during follicular development in yak.

The potential reproduction power of domestic animals is limited by a complicated follicular atresia process. P53, caspase-9 (Casp9), Bax, Bcl-2 and Fas play a crucial role in the ovarian mitochondrion-dependent apoptosis and death receptor pathway. In accordance with this study, the expression levels of Casp9, Bax, Bcl-2 and Fas were analysed in ovaries and oviducts of yak by immunohistochemistry (IHC). P53 and the above in ovarian granulosa cells (GCs) from atretic (3-6mm) to healthy follicles (6-8mm) and in oviducts were examined from the luteal phase to the follicular phase during the oestrous circle by Western blot (WB) and real-time PCR (RT-PCR). Results demonstrated that typical classic apoptotic factors Casp9, Bax, Bcl-2 and Fas were expressed in the cytoplasm and zonal pellucida of oocytes, primordial follicles, primary follicles, ovarian surface epithelium, ovarian GCs, granular lutein cells, surface epithelia in oviduct uterotubal junction and oviduct ampulla during the luteal phase. RT-PCR and WB revealed that P53 and Fas significantly increased in GCs of atretic follicles. P53 and Casp9 increased in oviduct epithelium during the luteal phase, but Fas was unchanged. A contrary tendency was noted in Bcl-2 and Bax expression. Overall, P53 and Fas play an essential role in inducing GC apoptosis, and Bax, Bcl-2, Casp9 and P53 are involved in oviduct epithelial regeneration in yak.

Mechanisms of High-Grade Serous Carcinogenesis in the Fallopian Tube and Ovary: Current Hypotheses, Etiologic Factors, and Molecular Alterations.

Ovarian high-grade serous carcinomas (HGSCs) are a heterogeneous group of diseases. They include fallopian-tube-epithelium (FTE)-derived and ovarian-surface-epithelium (OSE)-derived tumors. The risk/protective factors suggest that the etiology of HGSCs is multifactorial. Inflammation caused by ovulation and retrograde bleeding may play a major role. HGSCs are among the most genetically altered cancers, and TP53 mutations are ubiquitous. Key driving events other than TP53 mutations include homologous recombination (HR) deficiency, such as BRCA 1/2 dysfunction, and activation of the CCNE1 pathway. HR deficiency and the CCNE1 amplification appear to be mutually exclusive. Intratumor heterogeneity resulting from genomic instability can be observed at the early stage of tumorigenesis. In this review, I discuss current carcinogenic hypotheses, sites of origin, etiologic factors, and molecular alterations of HGSCs.

Fallopian Tube-Derived Tumor Cells Induce Testosterone Secretion from the Ovary, Increasing Epithelial Proliferation and Invasion.

Simple SummaryThe area between the fallopian tube and the ovary is of interest since the ends of the fimbria are the progenitor site for high grade serous cancer. Metabolomics revealed that androgens are induced at this site, which then increased proliferation of normal fallopian tube cells and their migration.The fallopian tube epithelium is the site of origin for a majority of high grade serous ovarian carcinomas (HGSOC). The chemical communication between the fallopian tube and the ovary in the development of HGSOC from the fallopian tube is of interest since the fimbriated ends in proximity of the ovary harbor serous tubal intraepithelial carcinoma (STICs). Epidemiological data indicates that androgens play a role in ovarian carcinogenesis; however, the oncogenic impact of androgen exposure on the fallopian tube, or tubal neoplastic precursor lesions, has yet to be explored. In this report, imaging mass spectrometry identified that testosterone is produced by the ovary when exposed to tumorigenic fallopian tube derived PTEN deficient cells. Androgen exposure increased cellular viability, proliferation, and invasion of murine cell models of healthy fallopian tube epithelium and PAX2 deficient models of the preneoplastic secretory cell outgrowths (SCOUTs). Proliferation and invasion induced by androgen was reversed by co-treatment with androgen receptor (AR) antagonist, bicalutamide. Furthermore, ablation of phosphorylated ERK reversed proliferation, but not invasion. Investigation of two hyperandrogenic rodent models of polycystic ovarian syndrome revealed that peripheral administration of androgens does not induce fallopian proliferation in vivo. These data suggest that tumorigenic lesions in the fallopian tube may induce an androgenic microenvironment proximal to the ovary, which may in turn promote proliferation of the fallopian tube epithelium and preneoplastic lesions.

Silencing PTEN in the fallopian tube promotes enrichment of cancer stem cell-like function through loss of PAX2

High-grade serous ovarian cancer (HGSOC) is the most lethal gynecological malignancy that is primarily detected at the metastatic stage. Most HGSOC originates from the fallopian tube epithelium (FTE) and metastasizes to the ovary before invading the peritoneum; therefore, it is crucial to study disease initiation and progression using FTE-derived models. We previously demonstrated that loss of PTEN from the FTE leads to ovarian cancer. In the present study, loss of PTEN in FTE led to the enrichment of cancer stem cell markers such as LGR5, WNT4, ALDH1, CD44. Interestingly, loss of the transcription factor PAX2, which is a common and early alteration in HGSOC, played a pivotal role in the expression of cancer stem-like cells (CSC) markers and cell function. In addition, loss of PTEN led to the generation of two distinct subpopulations of cells with different CSC marker expression, tumorigenicity, and chemoresistance profiles. Taken together, these data suggest that loss of PTEN induces reprogramming of the FTE cells into a more stem-like phenotype due to loss of PAX2 and provides a model to study early events during the FTE-driven ovarian cancer tumor formation.

Progesterone Receptors Promote Quiescence and Ovarian Cancer Cell Phenotypes via DREAM in p53-Mutant Fallopian Tube Models.

The ability of ovarian steroids to modify ovarian cancer (OC) risk remains controversial. Progesterone is considered to be protective; recent studies indicate no effect or enhanced OC risk. Knowledge of progesterone receptor (PR) signaling during altered physiology that typifies OC development is limited. This study defines PR-driven oncogenic signaling mechanisms in p53-mutant human fallopian tube epithelia (hFTE), a precursor of the most aggressive OC subtype. PR expression in clinical samples of serous tubal intraepithelial carcinoma (STIC) lesions and high-grade serous OC (HGSC) tumors was analyzed. Novel PR-A and PR-B isoform-expressing hFTE models were characterized for gene expression and cell cycle progression, emboli formation, and invasion. PR regulation of the DREAM quiescence complex and DYRK1 kinases was established. STICs and HGSC express abundant activated phospho-PR. Progestin promoted reversible hFTE cell cycle arrest, spheroid formation, and invasion. RNAseq/biochemical studies revealed potent ligand-independent/-dependent PR actions, progestin-induced regulation of the DREAM quiescence complex, and cell cycle target genes through enhanced complex formation and chromatin recruitment. Disruption of DREAM/DYRK1s by pharmacological inhibition, HPV E6/E7 expression, or DYRK1A/B depletion blocked progestin-induced cell arrest and attenuated PR-driven gene expression and associated OC phenotypes. Activated PRs support quiescence and pro-survival/pro-dissemination cell behaviors that may contribute to early HGSC progression. Our data support an alternative perspective on the tenet that progesterone always confers protection against OC. STICs can reside undetected for decades prior to invasive disease; our studies reveal clinical opportunities to prevent the ultimate development of HGSC by targeting PRs, DREAM, and/or DYRKs.

The Oxford Classic Links Epithelial-to-Mesenchymal Transition to Immunosuppression in Poor Prognosis Ovarian Cancers.

Using RNA sequencing, we recently developed the 52-gene-based Oxford classifier of carcinoma of the ovary (Oxford Classic, OxC) for molecular stratification of serous ovarian cancers (SOCs) based on the molecular profiles of their cell of origin in the fallopian tube epithelium. Here, we developed a 52-gene NanoString panel for the OxC to test the robustness of the classifier. We measured the expression of the 52 genes in an independent cohort of prospectively collected SOC samples (n = 150) from a homogenous cohort who were treated with maximal debulking surgery and chemotherapy. We performed data mining of published expression profiles of SOCs and validated the classifier results on tissue arrays comprising 137 SOCs. We found evidence of profound nongenetic heterogeneity in SOCs. Approximately 20% of SOCs were classified as epithelial-to-mesenchymal transition-high (EMT-high) tumors, which were associated with poor survival. This was independent of established prognostic factors, such as tumor stage, tumor grade, and residual disease after surgery (HR, 3.3; P = 0.02). Mining expression data of 593 patients revealed a significant association between the EMT scores of tumors and the estimated fraction of alternatively activated macrophages (M2; P < 0.0001), suggesting a mechanistic link between immunosuppression and poor prognosis in EMT-high tumors. The OxC-defined EMT-high SOCs carry particularly poor prognosis independent of established clinical parameters. These tumors are associated with high frequency of immunosuppressive macrophages, suggesting a potential therapeutic target to improve clinical outcome.

Control of oviductal fluid flow by the G-protein coupled receptor Adgrd1 is essential for murine embryo transit

Dysfunction of embryo transport causes ectopic pregnancy which affects approximately 2% of conceptions in the US and Europe, and is the most common cause of pregnancy-related death in the first trimester. Embryo transit involves a valve-like tubal-locking phenomenon that temporarily arrests oocytes at the ampullary-isthmic junction (AIJ) where fertilisation occurs, but the mechanisms involved are unknown. Here we show that female mice lacking the orphan adhesion G-protein coupled receptor Adgrd1 are sterile because they do not relieve the AIJ restraining mechanism, inappropriately retaining embryos within the oviduct. Adgrd1 is expressed on the oviductal epithelium and the post-ovulatory attenuation of tubal fluid flow is dysregulated in Adgrd1-deficient mice. Using a large-scale extracellular protein interaction screen, we identified Plxdc2 as an activating ligand for Adgrd1 displayed on cumulus cells. Our findings demonstrate that regulating oviductal fluid flow by Adgrd1 controls embryo transit and we present a model where embryo arrest at the AIJ is due to the balance of abovarial ciliary action and the force of adovarial tubal fluid flow, and in wild-type oviducts, fluid flow is gradually attenuated through Adgrd1 activation to enable embryo release. Our findings provide important insights into the molecular mechanisms involved in embryo transport in mice.