Tube Epithelium Research Articles

Tubal histopathological abnormalities in BRCA1/2 mutation carriers undergoing prophylactic salpingo-oophorectomy: a case–control study

ObjectiveTo describe tubal histopathological abnormalities in women with germline BRCA1/2 mutations and in controls.MethodsConsecutive women with BRCA1/2 mutations undergoing bilateral salpingo-oophorectomy between 2010 and 2020 in two centers (San Gerardo...

Characterization of Pathogenic CD8+ T cells in Chlamydia-Infected OT1 Mice.

Chlamydia trachomatis is a leading infectious cause of infertility in women due to its induction of lasting pathology such as hydrosalpinx. Chlamydia muridarum induces mouse hydrosalpinx because C. muridarum can both invade tubal epithelia directly (as a first hit) and induce lymphocytes to promote hydrosalpinx indirectly (as a second hit). In the current study, a critical role of CD8+ T cells in chlamydial induction of hydrosalpinx was validated in both wild type C57BL/6J mice and OT1 transgenic mice. OT1 mice failed to develop hydrosalpinx partially due to the failure of their lymphocytes to recognize chlamydial antigens. CD8+ T cells from naive C57BL/6J mice rescued the ability of recipient OT1 mice to develop hydrosalpinx when naive CD8+ T cells were transferred at the time of infection with Chlamydia. However, when the transfer was delayed for 2 weeks or longer after the Chlamydia infection, naive CD8+ T cells no longer promoted hydrosalpinx. Nevertheless, CD8+ T cells from mice immunized against Chlamydia still promoted significant hydrosalpinx in the recipient OT1 mice even when the transfer was delayed for 3 weeks. Thus, CD8+ T cells must be primed within 2 weeks after Chlamydia infection to be pathogenic, but, once primed, they can promote hydrosalpinx for >3 weeks. However, Chlamydia-primed CD4+ T cells failed to promote chlamydial induction of pathology in OT1 mice. This study optimized an OT1 mouse-based model for revealing the pathogenic mechanisms of Chlamydia-specific CD8+ T cells.

Endosalpingiosis - an Irrelevant Incidental Finding During Laparoscopy?

Endosalpingiosis - an Irrelevant Incidental Finding During Laparoscopy? Abstract. Endosalpingiosis refers to the ectopic presence of tubal epithelium. However, this incidental finding received little attention, although it is the second most common benign peritoneal pathology in women following endometriosis. In contrast to endometriosis, endosalpingiosis shows an increase in prevalence with age beyond the menopause. Furthermore, it does not appear to be chronically inflammatory and, according to research to this date, does not cause chronic pain or infertility. Recent epidemiological and molecular pathological studies show a significantly higher incidence of ovarian and endometrial tumors in women with endosalpingiosis. These correlations have not been conclusively clarified. Generally accepted clinical recommendations for the detection of endosalpingiosis do not yet exist. In order to better understand the disease value of endosalpingiosis and its oncological correlations, this entity should be brought to the attention of surgical gynecology and involved pathology.

Bacterial, archaea and viral transcripts (BAVT) expression in endometrial cancer

<h3>Objectives:</h3> Microbes are found virtually everywhere, including the human body. High-throughput sequencing of microbial genome, also known as metagenomic sequencing, may help to understand interactions between human and microbial processes. In this pilot study we aimed to determine differences of bacterial, archaea and viral expression between normal fallopian tube samples and ovarian and endometrial cancer samples. Then, we assessed these differentially expressed transcripts in endometrial and ovarian cancer from TCGA data. <h3>Methods:</h3> RNA was extracted and sequenced from 62 endometrial cancers, 104 high-grade serous ovarian cancers and 12 normal tubes specimens from our Biobank repository. Sequencing was performed using the Illumina HiSeq4000 platform that sequences 150 bp paired-end transcripts. Reads were processed with Centrifuge, a novel algorithm that classifies metagenomic sequences. We built our own index to differentiate between bacterial, archaea, viral and human transcripts. Resulting number of transcripts were normalized, log transformed and compared between tubal epithelium and ovarian and endometrial cancers (t-test). Lasso regression was used to identify significant independent transcripts between samples. TCGA ovarian and endometrial samples were processed as previously, and expression of significant probes were evaluated. <h3>Results:</h3> Bacterial, archaea and viral transcripts (BAVT) were 4.7% and 3,1% of all transcriptome in tubal and ovarian cancer respectively. 266 transcripts were differentially expressed between normal tubes and ovarian and endometrial cancer, with a p<0.005. 11 bacteria and 1 virus were independently significant in the multivariate regression model. These microbes were mapped close to genome regulatory areas. In general, there were more BVAT in normal tube samples. The amount of BAVT decreased in endometrial cancer and even more in ovarian cancer, supporting this regulatory role of BAVT. BAVTs in TCGA were 0.8% of all transcriptome. <h3>Conclusions:</h3> BAVT expression is different between normal tissues and cancers in the gynecologic tract. Cancer amount of BAVT seems to decrease in malignant tissues, supporting a regulatory role of BAVT. Further studies are needed to determine the significance of BAVT amount and change of expression.

Cytomorphologic clues for the diagnosis of fallopian tube prolapse in liquid-based vault samples with review of the literature.

Fallopian tube prolapse (FTP) is a rare complication of hysterectomy. The cytological features of the prolapsed fallopian tube in vault smears have been occasionally described in the literature. This was a retrospective study conducted to identify and describe the characteristic cytologic features of histopathologically confirmed cases of FTP in SurePath™ liquid-based preparations. Additionally, the literature documenting cytologic features of the prolapsed fallopian tube in vault smears was also reviewed. A total of four corresponding vault cytology samples of FTP cases, reported on histopathology, were available. On cytologic examination, these cases demonstrated strips and papillaroid clusters of columnar-shaped cells with mild nuclear enlargement, round to elongated nuclei, fine chromatin, inconspicuous nucleoli, and a moderate amount of wispy cytoplasm. Admixed inflammatory cells were also noted. Some of these cells demonstrated the presence of cilia and terminal bar toward the apical surface, indicative of tubal epithelium. The presence of three-dimensional papillaroid clusters lined by columnar cells as well as strips of similar cells with cilia and terminal bars at the apical surface and fine nuclear chromatin were the most consistent cytologic features in these cases. We conclude that a high index of clinical suspicion in post-hysterectomy cases with knowledge of the characteristic cytologic features can help in suggesting a diagnosis of tubal prolapse in vault samples.

Abstract LB248: Implantation factors assist in the growth of gynecologic tissues in ectopic locations

Abstract OBJECTIVE: Develop a model of endosalpingiosis and endometriosis to investigate the mechanisms which facilitate implantation of exfoliated cells in the peritoneum. BACKGROUND: Endosalpingiosis (ES) and endometriosis (EM) are the growth of tubal and endometrial epithelium respectively, outside of their site of origin and have been associated with ovarian cancer. Why this growth happens has not been elucidated since Sampson first proposed the concept of retrograde menstruation nearly 100 years ago. We hypothesized there is retrograde flow of uterine implantation factors which drive ectopic growth. To test this hypothesis, we developed a transgenic fluorescent murine model of ES and EM that successfully demonstrated peritoneal implantation in mice. Using the model, we explored possible influences on implantation. METHODS: tdTomato (tdT) transgenic fluorescent mice were used as donors to allow for visualization of tissues in recipient mice. A progesterone knockout (PKO) of the tdT mouse that blocks implantation factors was created by giving 0.1 mg/kg progesterone on postnatal days 2-10. Metestrus endometrium was induced hormonally in donor tdT and wild-type (WT) female C57BL/6J mice. The tdT oviductal cells and endometrium were then harvested for intraperitoneal injection into synchronized recipient WT mice, receiving minced endometrium alone, minced oviduct alone, or a combination of minced oviduct and WT endometrial tissue (for implantation factors) from non-treated or PKO tdT donors. Ectopic lesions were identified using fluorescence in-vivo imaging and UV light. RESULTS: PKO tdT oviduct had significantly reduced implantation (4 lesions/6 mice, p&amp;lt;0.02) compared to tdT oviduct without treatment (28 lesions/8 mice). Additionally, PKO tdT oviduct implantation (10 lesions/3 mice) may be restored when implanted with WT endometrium (p=0.07). Chi square was used to evaluate for statistical significance. ConclusionImplantation factors required for blastocyst implantation are crucial to initiate ectopic tissue growth. We have developed a novel mouse model of ectopic growth of gynecologic tissues which demonstrates that the removal of implantation factors from endometrium and oviduct reduces ectopic lesions. This model allows us to study the initial step of implantation of these lesions that could give rise to malignancies which will ultimately allow for the development of new prevention and treatment modalities. Citation Format: Jan Sunde, Derek O'Neil, Tiffany Katz, Morgan Wasickanin. Implantation factors assist in the growth of gynecologic tissues in ectopic locations [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 LB248.

New insights in the pathology of peritoneal surface malignancy.

Pathology is central to the management of peritoneal surface malignancy. This article highlights some recent advances that have had an impact on patient management or could do so in the near future. Malignant peritoneal mesothelioma, particularly the epithelioid subtype, is amenable to radical therapy in selected cases, and factors such as ki67 proliferation index, expression of BAP1 and mutation in CDKN2A show promise as prognostic indicators. Our understanding of multicystic mesothelioma has improved in recent years; it is a true neoplasm for which surgery may be indicated. Serous carcinomas involving the peritoneum are now known to originate from tubal epithelium. They are of two distinct types, high grade and low grade, which are now recognized as different neoplasms with distinctive features, oncogenesis and behavior. Pseudomyxoma peritonei (PMP) is an unusual condition that usually arises from an appendiceal mucinous neoplasm. Recent consensus in the classification and nomenclature of these lesions is discussed, including the distinction between low grade and high grade appendiceal mucinous neoplasms (HAMN), and the diagnostic criteria for appendiceal adenocarcinoma. PMP is divided into four prognostic groups: acellular mucin, low grade mucinous carcinoma peritonei, high grade mucinous carcinoma peritonei, and high grade mucinous carcinoma peritonei with signet ring cells. The pseudomyxoma microbiome is a promising area for clinical intervention but has been the subject of little research activity. Goblet cell adenocarcinoma (previously known as 'goblet cell carcinoid') is a distinctive type of appendiceal adenocarcinoma. Its behavior correlates with histologic features, but no general consensus for classification has been reached.

Cellular models of development of ovarian high-grade serous carcinoma: A review of cell of origin and mechanisms of carcinogenesis.

High‐grade serous carcinoma (HGSC) is the most common and malignant histological type of epithelial ovarian cancer, the origin of which remains controversial. Currently, the secretory epithelial cells of the fallopian tube are regarded as the main origin and the ovarian surface epithelial cells as a minor origin. In tubal epithelium, these cells acquire TP53 mutations and expand to a morphologically normal ‘p53 signature’ lesion, transform to serous tubal intraepithelial carcinoma and metastasize to the ovaries and peritoneum where they develop into HGSC. This shifting paradigm of the main cell of origin has revolutionarily changed the focus of HGSC research. Various cell lines have been derived from the two cellular origins by acquiring immortalization via overexpression of hTERT plus disruption of TP53 and the CDK4/RB pathway. Malignant transformation was achieved by adding canonical driver mutations (such as gain of CCNE1) revealed by The Cancer Genome Atlas or by noncanonical gain of YAP and miR181a. Alternatively, because of the extreme chromosomal instability, spontaneous transformation can be achieved by long passage of murine immortalized cells, whereas in humans, it requires ovulatory follicular fluid, containing regenerating growth factors to facilitate spontaneous transformation. These artificially and spontaneously transformed cell systems in both humans and mice have been widely used to discover carcinogens, oncogenic pathways and malignant behaviours in the development of HGSC. Here, we review the origin, aetiology and carcinogenic mechanism of HGSC and comprehensively summarize the cell models used to study this fatal cancer having multiple cells of origin and overt genomic instability.

Abstract PO032: Bacterial, archaea and viral transcripts (BAVT) expression in endometrial cancer

Abstract Objectives: Microbes are found virtually everywhere, including the human body. High-throughput sequencing of microbial genome, also known as metagenomic sequencing, may help to understand interactions between human and microbial processes. In this pilot study we aimed to determine differences of bacterial, archaea and viral expression between normal fallopian tube samples and ovarian and endometrial cancer samples. Then, we assessed these differentially expressed transcripts in endometrial and ovarian cancer from TCGA data. Methods: RNA was extracted and sequenced from 62 endometrial cancers, 104 high-grade serous ovarian cancers and 12 normal tubes specimens from our Biobank repository. Sequencing was performed using the Illumina HiSeq4000 platform that sequences 150 bp paired-end transcripts. Reads were processed with Centrifuge, a novel algorithm that classifies metagenomic sequences. We built our own index to differentiate between bacterial, archaea, viral and human transcripts. Resulting number of transcripts were normalized, log transformed and compared between tubal epithelium and ovarian and endometrial cancers (t-test). Lasso regression was used to identify significant independent transcripts between samples. TCGA ovarian and endometrial samples were processed as previously, and expression of significant probes were evaluated. Results: Bacterial, archaea and viral transcripts (BAVT) were 4.7% and 3,1% of all transcriptome in tubal and ovarian cancer respectively. 266 transcripts were differentially expressed between normal tubes and ovarian and endometrial cancer, with a p&amp;lt;0.005. 11 bacteria and 1 virus were independently significant in the multivariate regression model. These microbes were mapped close to genome regulatory areas. In general, there were more BVAT in normal tube samples. The amount of BAVT decreased in endometrial cancer and even more in ovarian cancer, supporting this regulatory role of BAVT. BAVTs in TCGA were 0.8% of all transcriptome. Conclusions: BAVT expression is different between normal tissues and cancers in the gynecologic tract. Cancer amount of BAVT seems to decrease in malignant tissues, supporting a regulatory role of BAVT. Further studies are needed to determine the significance of BAVT amount and change of expression. Citation Format: Silvana Pedra Nobre, Nicholas Cardillo, David Bender, Michael Goodheart, Eric Devor, Jesus Gonzalez Bosquet. Bacterial, archaea and viral transcripts (BAVT) expression in endometrial cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference: Endometrial Cancer: New Biology Driving Research and Treatment; 2020 Nov 9-10. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(3_Suppl):Abstract nr PO032.

Therapeutic effects of hysterosalpingography contrast media in infertile women: what do we know about the H2O in the H2Oil trial and why does it matter?

Recent interest in the use of oil-soluble contrast media (OSCM) for hysterosalpingography (HSG) and other tubal flushing procedures is largely the result of publication of the large, multicentre, randomized controlled H2Oil trial in the New England Journal of Medicine in 2017, addressing the long-held suspicion that pregnancy rates following HSG with OSCM are higher than if a water-soluble contrast media (WSCM) is used. However, the findings of this trial have been compromised by the WSCM selected for comparison with OSCM. The chosen WSCM belongs to a superceded class of ionic media, with an iodine concentration, osmolality and viscosity all lying at the extreme end of the range for water-soluble radiographic contrast. The requirement for safe, cheap, versatile WSCM for intravascular use during computerized tomography, angiography and interventional procedures has resulted in considerable refinement of WSCM, with current widespread use of non-ionic, low osmolality or iso-osmolar WSCM in radiology, including for HSG. However, the use of the earlier ionic, high osmolality agents such as that selected for the H2Oil trial persists for HSG in some centres, despite potential adverse effects on the endometrium and fallopian tubal epithelium compared with more modern, less toxic WSCM. Knowledge of the variety of physical and chemical characteristics of the available WSCM is essential for interpretation of the current literature and establishing the most effective and safe water-soluble agent to use for HSG. Design of future clinical trials to establish the potential superiority of OSCM over WSCM for fertility enhancement must include the use of the readily available, inexpensive modern WSCM. While the fertility rates following OSCM HSG have been shown to be high in women with idiopathic infertility, more robust trials are required before the widespread use of OSCM for HSG or other modalities such as ultrasound and laparoscopy should be adopted.

The immunohistochemical and histologic effects of contrast medium on uterus, fallopian tubes and ovaries, given during hysterosalpingography: rat study

Objective:Previous studies have shown that damage occurs to internal genital tract during hysterosalpingography (HSG). The aim was to show that endometrial and tubal epithelium underwent free radical damage during HSG in an animal model.Material and Methods:Forty rats were evaluated in five different groups. Two groups received ionizing radiation (15-20 miliRad three times) only. Two further groups received ionizing radiation in combination with iohexol (1-2 mL). The remaining group served as control. Groups were evaluated after seven and forty-two days. Inflammation and cellular changes were evaluated histopathologically. Cellular activity of antioxidant enzymes was assessed immunohistochemically.Results:Inflammation, and cellular changes were detected at certain rates in all groups (p<0.001). Glutathione reductase, catalase, superoxide dismutase, glutathione S-transferase activities were found to be increased after the HSG (p<0.001).Conclusion:It is obvious that the cell suffers acute and chronic damage during HSG due to both radioactivity and chemicals. Although there is a lot of research done before, there is no definitive method yet to protect against the harmful effects of iodinated contrast agents and ionizing radiation. So, new methods need to be explored to protect cells and tissues from reactive oxygen radical damage caused by HSG.

Müllerianosis de cuello uterino. Reporte de caso

La müllerianosis es una enfermedad embrionaria de los conductos de Müller o paramesonéfricos, que consiste en la mezcla de dos o más tipos de tejidos y que da como resultado la formación de adenomiosis, endometriosis, endosalpingiosis y endocervicosis. Con mayor frecuencia afecta la vejiga urinaria de las mujeres en edad fértil. La müllerianosis del cuello uterino es una afección benigna muy rara, con pocos casos reportados. La patogenia exacta sigue siendo tema de debate. Existen varias teorías sobre su etiología; las dos principales son la teoría de implantación y la metaplásica. Los síntomas varían desde su ausencia hasta dolor pélvico y dismenorrea. Generalmente aparece como tumor quístico con glándulas de diferentes tamaños revestidas por epitelio endometrial, endocervical o tubárico. Esta lesión podría confundirse con otras lesiones benignas, premalignas o malignas y es necesario la confirmación histopatológica. Debido a que es una enfermedad benigna, no necesita tratamiento adicional luego de la resección quirúrgica. Se presenta un caso de müllerianosis del cuello uterino.

Clinicopathological and molecular analyses of linearly expanded epithelial cells with β-catenin alterations, "β-catenin signature", in the normal fallopian tube.

Recent advances in next-generation sequencing have made it clear that clonal expansion of cells harbouring driver gene mutations occurs in physiologically normal epithelium. Molecular analysis of tubal epithelium has been almost exclusively confined to the TP53 pathway, which is involved in serous carcinogenesis. Other oncogenic events have not been explored in detail. Here, we report the linear expansion of fallopian tubal epithelial cells exhibiting an altered β-catenin profile (β-catenin signature). Through molecular analyses, we determined the incidence and clinicopathological significance of β-catenin signatures. We evaluated 64 specimens of surgically removed bilateral fallopian tubes. Thirty-three β-catenin signatures were identified in 13 cases (20.3%); these patients were significantly younger than those without β-catenin signatures (median ages of 44 and 57years, respectively, P=0.0317). No correlation between β-catenin signature and any clinical factor was observed. CTNNB1 mutations were detected in three of eight β-catenin signatures when tissues were microdissected and subjected to Sanger sequencing in two representative cases. This is the first report of the CTNNB1 mutation in clusters of morphologically bland tubal epithelial cells. The results of this study indicate that β-catenin signatures are common, and they may be a part of diverse molecular alterations occurring in normal tubal epithelium.

Examination of expression patterns of WNT signaling in the human fallopian tubes

The fallopian tubes are a pair of tubes extending between the uterus and ovaries, and are examined in four different anatomical sections. Each anatomical section is known to have different structural features and cell distributions. Wnt signaling pathway ligands, which are important in the control of developmental events, stem cells and cell behaviors, are released from the fallopian tubes under physiological and pathological conditions. In this study, the purpose was to perform quantitative analysis of canonical Wnt pathway ligands in different anatomical regions of human fallopian tubes, evaluate the Wnt3a ligand in immunohistochemical terms, and to show that these different sections are not affected by pathologies in light microscopy. For this purpose, unilateral fallopian tube tissues taken from 5 patients in secretory phase were divided into three regions as proximal, distal and ampulla. The reverse transcriptase quantitative PCR method revealed the expression of 7 of 8 different canonical Wnt pathway ligands in Fallopian tubes. Wnt1, Wnt3, Wnt3a, Wnt8b, Wnt10a, and Wnt10b ligands showed higher expression levels in fimbriae, whereas Wnt3a expression was significantly lower in the proximal section than in the distal and ampulla sections. When Wnt3a ligand was evaluated immunohistochemically, it was observed to be intensely localized in tube epithelium and lamina propria. The presence of Wnt ligands suppressed in secretory phase by fallopian tubes shows the importance of this pathway in tube homeostasis. It was shown that Wnt ligands can be considered as protective factors of stemness in fallopian tubes.

Low Expression of Claudin-7 as Potential Predictor of Distant Metastases in High-Grade Serous Ovarian Carcinoma Patients.

High-grade serous ovarian carcinoma (HGSOC) usually spreads directly into the peritoneal cavity following a transcoelomic dissemination route, although distant hematogenous metastasis exist and have been reported. However, no tumor markers can currently predict the risk of distant metastases in HGSOC. Claudins, belonging to tight-junction proteins, are dysregulated in HGSOC and functionally related to cancer progression. Here we analyzed claudin-3, -4, and -7 expression as potential markers of distant metastases. Using quantitative RT-PCR and immunohistochemistry we assessed the expression of claudins in primary HGSOC tissues, normal ovarian, and normal fallopian tube epithelia and correlated it with clinicopathological features, including the site of metastasis and the route of dissemination. Gene set enrichment analysis was performed on microarray-generated gene expression data to investigate key pathways in patients with distant metastases. We found the overall expression level of claudin-3, -4, and -7 mRNA decreased in HGSOC compared to normal tubal epithelium, currently considered the potential site of origin of many HGSOC. The reduced expression of claudin-7 is significantly associated with the development of distant metastases (p = 0.016), mainly by hematogenous route (p = 0.025). In patients with diminished expression of claudin-7, immunohistochemical staining revealed a heterogeneous pattern of membranous staining with discontinuous expression of claudin-7 along the cell border, indicative of a dischoesive architecture. The estimated reduction in the probability of distant disease is of 39% per unit increase in the level of claudin-7 (p = 0.03). Genes involved in epithelial to mesenchymal transition, hypoxia, and angiogenesis processes resulted strongly associated to hematogenous recurrence. Our data suggest a potential role of claudin-7 in discriminating distant metastatic events in HGSOC patients. The quantification of its expression levels could be a useful tool to identify patient deserving a personalized follow-up in terms of clinical and radiological assessment.

Abstract B26: The natural history of ovarian high-grade serous carcinoma from time effects of ovulation inhibition and progesterone clearance of p53-defective lesions

Abstract High-grade serous carcinoma (HGSC) is the most common and devastating type of ovarian cancer; its etiology, mechanism of malignant transformation, and origin remain controversial. Recent studies have identified secretory cells at the fimbria of the fallopian tube as the cell of origin of HGSC, initiating TP53 mutation, evolving to tubal precursor lesions, including “p53 signature” and serous tubal intraepithelial carcinoma (STIC), and metastasizing to the ovary as clinically evident ovarian cancer. The etiologic mechanisms associated with the known epidemiologic risk factors, i.e., ovulation and retrograde menstruation, have also been unveiled. Mutagens and transforming growth factors, such as reactive oxygen species and IGF axis proteins, as well as the apoptosis-rescuing protein hemoglobin are abundantly present in the ovulatory follicular fluid and peritoneum fluid, which bathes the fimbrial epithelium, and induces malignant transformation after repeated exposure. Meanwhile, in accordance with the proposed therapeutic effect of progesterone from studies on oral contraceptive (OC) use or term pregnancy, our recent study indicated that the p53-null tubal epithelial cells are selectively cleared by progesterone depending on its progesterone receptor (PR). In this report, by analyzing different time-effects of OC use or pregnancy in the prevention of ovarian cancer and by aligning them with the carcinogenic and therapeutic clearance concepts of ovulation and P4, as well as the fact of progressive loss of PR during tubal transformation, we deduced the natural history of ovarian HGSC. The natural history begins at the first ovulation and spans more than 30 years, taking 10 years from the normal tubal epithelium to the “p53 signature” status, another 15 years to PR(-) STIC, and a final 5+ years to HGSC. The estimated natural history may help understand the pathogenesis of HGSC and defines the window for early detection and chemoprevention. Citation Format: Tang-Yuan Chu, Na-Yi Yuan Wu, Jing Wang. The natural history of ovarian high-grade serous carcinoma from time effects of ovulation inhibition and progesterone clearance of p53-defective lesions [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr B26.

Abstract B11: Collective extrusion initiates dissemination in organotypic model of high-grade serous carcinoma

Abstract Development of serous tubal intraepithelial carcinoma (STIC) from transformed fallopian tube secretory epithelial cells (FTSEC) is considered to be an initiating event for a significant proportion of high-grade serous carcinomas (HGSCs). Some regions of STIC lesions can form multicellular loosely cohesive outgrowths that apically extend out of the tubal epithelium. These outgrowths can detach and disseminate within the peritoneal cavity, causing organ obstruction. Immunohistochemical analysis of STICs suggests the possibility that molecular pathways associated with proliferation, DNA repair, cytoskeletal dynamics, and extracellular matrix adhesion contribute to outgrowth formation. Due to limited availability of transformed FTSEC in vitro culture models that faithfully capture outgrowth dynamics, the role of these pathways in STIC/HGSC outgrowth formation remains unknown. Here we present the development of an organotypic model of outgrowth formation. Long-term live-cell imaging of transformed human, and mouse FTSEC and STIC-like multicellular organotypic assemblies, have shown that outgrowths are initiated by collective apical extrusion of less-cohesive, loosely attached cell populations that can proliferate outside of the organotypic assembly. mRNA and immunofluorescence analysis of loosely attached cell populations revealed: (i) activation of Rho pathway, (ii) increased expression of several alpha integrin subunits that form heterodimers with beta 1 integrin, and (iii) nonpolarized apical and junctional localization of activated integrin beta 1. Pharmacologic or genetic inhibition of Rho-associated kinase (ROCK) blocked outgrowth formation without affecting cell proliferation. Conversely, activation of Rho significantly accelerated outgrowths, indicating that Rho-ROCK is a critical regulator of early steps of HGSC dissemination. Quantitative image-based evaluation of ROCK target phosphorylated myosin light chain expression in patient-derived xenograft cells revealed the presence of cell populations with high ROCK activation. Blocking integrin beta 1 activity resulted in the disintegration of already formed outgrowths. Our data indicate that cell populations with high Rho/ROCK activity remodel integrin beta 1-dependent adhesion to initiate apical extrusion and peritoneal dissemination. Citation Format: Sarah Alshehri, Sadaf Farsinejad, Douglas Kung, Estefan Santi, Yali Zhai, Thomas Cattabiani, Hongjun Wang, Kathleen Cho, Marcin Iwanicki. Collective extrusion initiates dissemination in organotypic model of high-grade serous carcinoma [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr B11.

Abstract B21: Oncogenic BRAF and KRAS mutations in endosalpingiosis

Abstract Endosalpingiosis, or ectopic fallopian tube epithelium, frequently involves the peritoneum and lymph nodes in patients with ovarian low-grade serous borderline tumor or carcinoma, but the pathogenic significance of these microscopic lesions remains unclear. Using laser-capture microdissection and digital droplet PCR, we investigated whether endosalpingiosis harbors the driver mutations in BRAF and KRAS, commonly seen in low-grade serous tumors. Of 21 women with endosalpingiosis associated with a synchronous or metachronous ovarian low-grade serous tumor, mutations were identified in 11 (52%) cases and the identical mutation was shared between the tumor and endosalpingiosis in 10/11 cases. In contrast, of 12 cases of endosalpingiosis not associated with an ovarian tumor, only 1 harbored a KRAS mutation. Across mutation-positive cases, the median mutant allelic frequency was 37% (range: 12 – 67%). Ki-67 immunohistochemical staining revealed significantly decreased proliferative index in endosalpingiosis relative to low-grade serous tumors, but no difference with eutopic tubal epithelium. BRAF or KRAS-mutated endosalpingiosis had significantly lower Ki-67 index compared to lesions lacking mutations in both genes. Functional studies using fallopian tube epithelial cell cultures demonstrate that enforced expression of KRAS-G12V causes phosphorylation of downstream ERK, with associated growth impairment and induction of p21, suggesting oncogene-induced senescence. We demonstrate that endosalpingiosis represents a striking example of cancer driver mutations in deceptively normal-appearing cells, signifying this innocuous-appearing lesion as a monoclonal proliferation with neoplastic potential. Citation Format: M. Herman Chui, Ie-Ming Shih. Oncogenic BRAF and KRAS mutations in endosalpingiosis [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr B21.

Importance of serous intraepithelial ovarian tubal carcinomas in the occurrence of "high-grade" serous carcinomas and / or peritoneal serous carcinomas of unknown primary origin.

Studies of the recent decades on serous pelvic adenocarcinomas in women have set the goal of distinguishing between two diagnostic units: "low-grade" and "high-grade" carcinomas. The predecessor of the "low-grade" variant (type I) is considered to be a borderline serous tumor / atypical proliferative serous tumor (8442/1), which according to the International Classification of Diseases for Oncology ICD-O 2013 of the female reproductive system refers to non-specific, borderline tumors and tumors with unpredictable clinical behavior. The predecessors of the “high-grade” variant (type II) are serous tubular intraepithelial carcinomas (in situ) or “high-grade” serous invasive tubal carcinomas, since they have the TP53 mutation identical to “high-grade” ovarian carcinoma, an aberrant p53 protein expression, high proliferative activity, and significant genomic instability. In addition, according to the carcinogenesis of "high-grade" serous ovarian carcinoma with metastases to the peritoneum, it can also be interpreted as "pelvic high-grade serous carcinoma". A retrospective analysis of the histological, morphometric and immunohistochemical characteristics of the biopsy material of 31 women aged from 28 to 76 years (mean 57.32±11.54; median 57), divided into 3 groups, was carried out. Group 1: 14 observations of the tubal epithelium (8 tubes without pathological changes (subgroup 1a) and 6 with signs of intraepithelial neoplasia (subgroup 1b); group 2: 12 cases of serous adenocarcinoma of the ovary of the “high-grade” variant; group 3: 6 metastatic peritoneal serous carcinoma without a known primary site. Results. Group immunophenotypes showed uniformity in the expression of markers CK7 (+, +/-), CK20 (-), WT-1 (+), CA125 (+, +/-), with an affinity to distal uterine tube fragments. The expression of p53 in all groups with signs of carcinomas (compared with the control subgroup 1a without atypia) was divided into two options - negative samples and samples with overexpression, where no statistically significant difference was found (p&gt;0.05), which is possibly a single way of carcinogenesis. The morphometric study revealed a significant difference in the area of the nuclei between group 3 and the first three groups (1a, 1b, 2), which indicates the similarity of ovarian and tubal neoplasias and uterine tube epithelium. The number of intranuclear reactions with ER and PGR progressively decreased from group 1 to group 3, with an increase in cases with ER (+/-) / PGR (+/- or -) to 50% in group 3, which greatly complicated the diagnostic search for unknown carcinomas of primary localization. HER-2-new expression revealed a possible amplification (gradation 2 + / 3 +) only in group 2 at the level of 16.67% and in group 3 at the level of 33.33%.

Adrenomedullin insufficiency alters macrophage activities in fallopian tube: a pathophysiologic explanation of tubal ectopic pregnancy.

Ectopic pregnancy is the major cause of maternal morbidity and mortality in the first trimester of pregnancy. Tubal ectopic pregnancy (TEP) accounts for nearly 98% of all ectopic pregnancies. TEP is usually associated with salpingitis but the underlying mechanism in salpingitis leading to TEP remains unclear. Adrenomedullin (ADM) is a peptide hormone abundantly expressed in the fallopian tube with potent anti-inflammatory activities. Its expression peaks at the early luteal phase when the developing embryo is being transported through the fallopian tube. In the present study, we demonstrated reduced expression of ADM in fallopian tubes of patients with salpingitis and TEP. Using macrophages isolated from the fallopian tubes of these women, our data revealed that the salpingistis-associated ADM reduction contributed to aggravated pro-inflammatory responses of the tubal macrophages resulting in production of pro-inflammatory and pro-implantation cytokines IL-6 and IL-8. These cytokines activated the expression of implantation-associated molecules and Wnt signaling pathway predisposing the tubal epithelium to an adhesive and receptive state for embryo implantation. In conclusion, this study provided evidence for the role of ADM in the pathogenesis of TEP through regulating the functions of tubal macrophages.