Origin Of Epithelial Ovarian Cancer Research Articles

Abstract B106: A minimal driver pair for a spontaneous high-grade serous ovarian cancer mouse model: Myc and p53-R270H

Abstract Genetically engineered mouse models (GEMM) have fundamentally changed how ovarian cancer etiology, early detection, and treatment can be understood. One challenge of the last decade has been to provide evidence for which cells are responsible for the origin of epithelial ovarian cancer. Different promoters, including Pax8, Lgr5, Ogvp1, and others have allowed for expression of transgenes in specific epithelial compartments in mice. Ovgp1 has been shown to be specific for fallopian tube epithelium (FTE), which most HGSOC is now thought to originate from. Pairing Ovgp1 with multiple homozygous deletions of powerful tumor suppressors like Brca1, Trp53, Rb1, and Nf1 yields murine disease after a year of age. However, human tumors do not contain homozygous deletions of these many tumor suppressors. Others have utilized Pax8 to knock out Trp53 and Pten to yield tumors at 3-8 months of age, but human tumors rarely have PTEN knockouts and Pax8 drives kidney and thyroid expression as well. We postulated that it is possible to strictly mimic human HGSOC genetics in a mouse model and nonetheless drive oncogenesis within the lifespan of a mouse. Here, we describe the OvTrpMyc model, Trp53em1Jdel_Tg(Ovgp1-Trp53*R270H-Myc), in which p53-R270H and Myc expression are driven by the Ovgp1 promoter. The transgene was inserted at the endogenous Trp53 locus, predicting that this design would allow for loss of the opposing wild-type chromosome 11 (syntenic to chromosome 17 in humans) to better mimic human HGSOC genetics. This model generated lethal disease at a median of 15.6 months of age. Dissected metastatic tumors were peritoneal and expressed Pax8, consistent with human disease. Immunohistochemical staining of the fallopian tube, ovary, and uterus indicated clear nuclear staining of p53 and Myc on the FTE. Notably, pockets of intraepithelial metastases expressing p53 and Myc were also found on the uterine epithelium. Cells grown ex vivo from uterus or fallopian tube dissections were analyzed for transcriptomes. RNA-seq revealed a clustering of these extracted cancer cells with human HGSOC and p53 mutant serous endometrial cancers. Loss of heterozygosity at the p53 locus was universal in these ex vivo grown cancer cells, as was extensive aneuploidy. The OvTrpMyc model requires only a single transgene for its breeding strategy, better enabling cancer detection, prevention, and treatment experiments. Taken together, the OvTrpMyc model of p53-R270H mutation and Myc expression driven by Ovgp1 is sufficient to recapitulate cancer hallmarks of HGSOC and, surprisingly, p53 mutant serous uterine cancer as well. Citation Format: Joe R Delaney. A minimal driver pair for a spontaneous high-grade serous ovarian cancer mouse model: Myc and p53-R270H [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr B106.

Frequency and Management Outcome in Gynecological Malignancies

Objective: The study was done to find out the frequency of different gynaecological malignancies, histological types and management outcome of these malignancies. Material and Methods: This study was conducted in unit III of Obtetrics and Gynecology Department, Jinnah Hospital, Lahore. Duration of study was 2 years from January 2018 to December 2019 and sample size was 81. All the cases presented with gynaecological cancer was analysed retrospectively by reviewing record. Complete data was evaluated in term of frequency of malignancies and their percentages. Results: The most common site of gynaecological malignancy was cervical 35 cases (43.2%) followed by ovarian 30 cases(37%).Uterine wasthe 3rd most common tumour with 13 cases(16%).The vulval and vaginal cancers were found to be lowest with 01 case each (1.2%). There was one case of choriocarcinoma (1.2%). Conclusion: Cervical cancer was the commonest cancer with squamous cell histological type (80%) followed by ovarian cancer of epithelial origin (73.3%).

Clinical significance of detection of micrometastases in lymph nodes in ovarian cancer

Ovarian cancer of epithelial origin is the most common type of oncological process in this organ and is characterized by a high probability of fatal outcome. It is believed that this is due to insufficiently effective diagnosis of the prevalence and severity of this disease. This review presents data on the development of disease recurrence in a significant number of patients after cytoreductive surgery. According to some authors, the reason for the high risk of recurrence is the insufficient information content of the method of studying histological preparations of regional lymph nodes after staining with hematoxylin and eosin to detect small-sized metastases, including isolated tumor cells and micrometastases. To improve the accuracy of such diagnostics, it is recommended to supplement the study of multilevel sections of lymph nodes using routine staining with the use of immunohistochemistry and other methods using various antibodies to cytokeratins, along with other epithelial markers. The review provides an analysis of the opinions of various researchers on the prognostic significance of the detection of micrometastases in the lymph nodes, which can increase the effectiveness of therapy due to a more accurate assessment of the prevalence of the disease and correction of the tactics of treating patients with various oncological diseases.

Molecular markers derived from ovarian cancer and its correlation with the types of oviductal epithelial lesions

To explore the role of P53, pairing box gene 8 antibody (PAX8), and calcium omentum protein (Calretinin) in the origin of epithelial ovarian cancer. Methods: A total of 63 tissue samples of ovarian tumor and fallopian tubes were collected. Immunohistochemistry methods were used to analyze the expression of P53, PAX8, and Calretinin. The relationship between these protein levels and the classification of ovarian tumors was evaluated. Results: In epithelial ovarian cancer, the P53 or PAX8 was correlated with the occurrence of high-grade carcinoma, while the calretinin was correlated with the occurrence of low-grade carcinoma (P<0.05). The combination of PAX8 with Calretinin was correlated with the grade of ovarian tumor (P<0.05). The combination of P53 with Calretinin was correlated with the grade of tumor (P<0.05). The combination of P53 with PAX8 was correlated with the grade of tumor (P<0.05). The expression of P53 in fallopian tubes was correlated with the malignant degree of epithelial ovarian cancer (P<0.05). The degree of fallopian tube lesions in patients with ovarian cancer was correlated with epithelial ovarian cancer. The malignant lesions of tubal epithelium was correlated with high-grade carcinoma, while the normal or atypical hyperplasia of tubal epithelium was correlated with low-grade carcinoma (P<0.05). Conclusion: P53 and Calretinin combined with PAX8 show a synergistic effect on the differentiation of epithelial ovarian cancer grade. The morphology of HE and the expression of TP53 in the fallopian tube epithelium play an auxiliary role in the diagnosis of epithelial ovarian cancer.

Estradiol and Progesterone Induced Differentiation and Increased Stemness Gene Expression of Human Fallopian Tube Epithelial Cells.

Fallopian tube epithelial cells (FTECs) are thought to be the origin of epithelial ovarian cancer. However, the effect of the hormones on FTECs is unknown, and therefore, this study explored this effect. We successfully derived FTECs from the fallopian tube epithelial layer and treated them with estradiol and progesterone. Reverse transcription polymerase chain reaction was used to evaluate the gene expression of the FTECs' hormone receptors. Confocal and electron microscopy were used to evaluate the morphology of the FTECs after they were treated with hormones. Finally, quantitative PCR was used to evaluate the gene expression of the hormone-treated FTECs. The results showed that the FTECs exhibited cuboidal cell morphology and could be maintained at a constant proliferation rate. Furthermore, flow cytometry revealed that the FTECs expressed stem cell markers, such as SSEA3, SSEA4, and Lgr5. Moreover, the FTECs could express both estrogen and progesterone receptors. In a culture treated with 400 nM estrogen, the FTECs differentiated toward ciliated cells, whereas in a culture treated with estradiol or progesterone, the FTECs increased their expression of certain stem cell markers (SSEA3, SSEA4, and Aldh1) and stemness genes [Wnt (AXIN2, LGR5, LGR6, and OLFM4) and Notch (Hes1) signaling]. In conclusion, hormones may alter the gene expressions of FTECs, and these cells may provide new insights into how FTECs regenerate in response to hormones.

Risks and Benefits of Opportunistic Salpingectomy During Vaginal Hysterectomy: A Decision Analysis

(Abstracted from Am J Obstet Gynecol 2017;217:603.e1–603.e6) With strong evidence that the origin of epithelial ovarian cancer is in the fallopian tube, use of opportunistic salpingectomy to remove the tubes can decrease incidence of ovarian cancer and avoid the need for oophorectomy. The American Congress of Obstetricians and Gynecologists (ACOG) recommends that concomitant salpingectomy should be considered with every hysterectomy.

Ovarian cancer: current approaches to classification, diagnostics, staging and differential management of patients

Purpose of this study: systematic analysis of the data available in the modern scientific medical literature on contemporary aspects of the diagnosis, staging and differential treatment tactics of patients with epithelial ovarian tumors.&#x0D; Research method used in this article is the systematic analysis of the medical literature, both domestic and western.&#x0D; Results. This article attempts to summarize the experience of modern medicine and the world’s leading centers for the fight against ovarian cancer of epithelial origin and offer solutions relevant to everyday clinical practice. Problems of the modern classification of forms of the disease are described in detail; description of instrumental diagnostic methods also is given in thus article; problem of lack of effective proved themselves in clinical practice of screening methods also was disccused; and, thus, current understanding of the disease staging and differential tactics for treatment of patients are given.&#x0D; Conclusion. One of the most important directions of development of gynecological oncology is a decision the existing problems related to the diagnosis and treatment of ovarian cancer: namely, the development of effective screening programs, improving diagnosis and therapy methods, the development of measures of postoperative management of patients with ovarian cancer, including medical rehabilitation measures.

The clinical implications of new insights into the origins of epithelial ovarian cancer with emphasis on the British Columbia Ovarian Cancer Prevention Initiative

In the last ten years our understanding of the origin of epithelial ovarian cancer has changed. This includes the realization that the majority of High Grade serous cancers originate in fallopian tube epithelium and the majority of endometroid and clear cell cancer arise in foci of endometriosis. These new insights have profound implications of both prevention and treatment.

CURRENT OPINIONS CONCERNING THE PATHOGENESIS OF EPITHELIAL OVARIAN CANCER AND NEW DIAGNOSTIC APPROACHES TO THE DISEASE

Because of high mortality rate, the lack of effective methods for early diagnosis and limited success in treatment, ovarian cancer of epithelial origin is a major problem in gynecological oncology. These problems are largely due to our lack of the disease etiopathogenesis understanding. This article attempts to summarize recent data on the sources and the development of the cancer process in the ovary as well as to introduce modern approaches to the diagnosis of this type of malignancy.

EPITHELIAL OVARIAN CANCER. CLINICAL LECTURE

About 90 percent of ovarian cancers are epithelial tumors. High mortality rates, the lack of effective methods for early diagnosis and treatment make of the ovarian cancer a relevant problem for modern oncology. Only a wide application of clinical guidelines developed by professional societies based on the principles of evidence-based medicine could improve prognosis for that group of patients. This article attempts to summarize the experience of the world's leading centers for the fight against ovarian cancer of epithelial origin and offer solutions relevant to everyday clinical practice.

Opportunistic salpingectomies for the prevention of a high-grade serous carcinoma: a statement by the Kommission Ovar of the AGO.

The detection of premalignant cells in the epithelium of the fallopian tube has resulted in revolutionary theories regarding the origin of epithelial ovarian cancer (EOC). Serous tubal intra-epithelial carcinomas (STIC) have been detected in patients with BRCA 1 or 2 mutations and are considered as the most likely precursors of the high-grade serous ovarian cancer (HGSOC), which is the most common histological subtype in patients with EOC. A bilateral salpingo-oophorectomy is associated with a significant reduction in risk of developing EOC. According to various national guidelines, prophylactic bilateral salpingo-oophorectomy should be performed in the age group 40-45 years. As in patients with BRCA mutations, the prophylactic removal of the fallopian tubes is also performed in women without an increased genetic risk, for example, in surgical treatments of benign conditions. There is a current debate as to whether prophylactic or so-called opportunistic salpingectomy will influence the overall incidence of EOC in the coming years. Opponents of this theory warn of a higher surgical morbidity and the higher risk of a premature menopause through impaired vascular supply to the ovaries. The value of opportunistic salpingectomies has not yet been clarified since there are currently no systematic risk-benefit evaluations. This review will attempt to give an overview of the current body of evidence regarding the risks and benefits of opportunistic salpingectomies.

Role of the stem cell niche in the pathogenesis of epithelial ovarian cancers

Ovarian cancer is the fifth leading cause of cancer-related deaths among women in the United States. Recent extensive genomic analyses of epithelial ovarian cancer (EOC), particularly the most common and deadly form of high-grade serous ovarian carcinoma, have provided important insights into the repertoire of molecular aberrations that are characteristic for this malignancy. However, interpretation of the discovered aberrations is complicated because the origin and mechanisms of progression of EOC remain uncertain. Here, we summarize current views on the cell of origin of EOC and discuss recent findings of a cancer-prone stem cell niche for ovarian surface epithelium, one of the major likely sources of EOC. We also outline future directions and challenges in studying the role of stem cell niches in EOC pathogenesis.

Abstract IA4: A dualistic model of ovarian carcinogenesis

Abstract Recent morphologic, immunohistochemical and molecular genetic studies have led to the development of a new paradigm for the pathogenesis and origin of epithelial ovarian cancer (EOC) based on a dualistic model of carcinogenesis that divides EOC into two broad categories designated type I and type II. Type I tumors are comprised of low-grade serous, low-grade endometrioid, clear cell and mucinous carcinomas and Brenner tumors. They are generally indolent, present in stage I (tumor confined to the ovary) and are characterized by specific mutations, including KRAS, BRAF, ERBB2, CTNNB1, PTEN PIK3CA, ARID1A, and PPPR1A, which target specific cell signaling pathways. Type I tumors rarely harbor TP53 and are relatively stable genetically. Type II tumors are comprised of high-grade serous, high-grade endometrioid, malignant mixed mesodermal tumors (carcinosarcomas) and undifferentiated carcinomas. They are aggressive, present in advanced stage, and have a very high frequency of TP53 mutations but rarely harbor the mutations detected in type I tumors. In addition, type II tumors have molecular alterations that perturb expression of BRCA either by mutation of the gene or by promotor methylation. A hallmark of these tumors is that they are genetically highly unstable. Recent studies strongly suggest that fallopian tube epithelium (benign or malignant) that implants on the ovary is the source of low-grade and high-grade serous carcinoma rather than the ovarian surface epithelium as previously believed. Similarly, it is widely accepted that endometriosis is the precursor of endometrioid and clear cell carcinomas and as endometriosis is thought to develop from retrograde menstruation these tumors can also be regarded as involving the ovary secondarily. The origin of mucinous and transitional cell (Brenner) tumors is still not well established, although recent data suggest a possible origin from transitional epithelial nests located in paraovarian locations at the tubo-peritoneal junction. Thus, it now appears that type I and type II ovarian tumors develop independently along different molecular pathways, and that both types develop outside the ovary and involve it secondarily. If this concept is confirmed it leads to the conclusion that the only true primary ovarian neoplasms are gonadal stromal and germ cell tumors analogous to testicular tumors. This new paradigm of ovarian carcinogenesis has important clinical implications. By shifting the early events of ovarian carcinogenesis to the fallopian tube and endometrium instead of the ovary, prevention approaches, for example, salpingectomy with ovarian conservation, may play an important role in reducing the burden of ovarian cancer while preserving hormonal function and fertility. Citation Format: Robert J. Kurman. A dualistic model of ovarian carcinogenesis. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: From Concept to Clinic; Sep 18-21, 2013; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2013;19(19 Suppl):Abstract nr IA4.

Gene Expression Analyses Support Fallopian Tube Epithelium as the Cell of Origin of Epithelial Ovarian Cancer

Folate receptor alpha (FOLR1/FRA) is reported to be overexpressed in epithelial ovarian cancers (EOC), especially the serous histotype. Further, while dysregulation of the folate-dependent 1-carbon cycle has been implicated in tumorogenesis, little is known relative to the potential mechanism of action of FOLR1 expression in these processes. We therefore investigated the expression of FOLR1, other folate receptors, and genes within the 1-carbon cycle in samples of EOC, normal ovary and fallopian tube on a custom TaqMan Low Density Array. Also included on this array were known markers of EOC such as MSLN, MUC16 and HE4. While few differences were observed in the expression profiles of genes in the 1-carbon cycle, genes previously considered to be overexpressed in EOC (e.g., FOLR1, MSLN, MUC16 and HE4) showed significantly increased expression when comparing EOC to normal ovary. However, when the comparator was changed to normal fallopian tube, these differences were abolished, supporting the hypothesis that EOC derives from fallopian fimbriae and, further, that markers previously considered to be upregulated or overexpressed in EOC are most likely not of ovarian origin, but fallopian in derivation. Our findings therefore support the hypothesis that the cell of origin of EOC is tubal epithelium.

New hypothesis on pathogenesis of ovarian cancer lead to future tailored approaches.

In the last decades, management of epithelial ovarian cancer (EOC) has been based on the staging system of the International Federation of Gynecology and Obstetrics (FIGO), and different classifications have been proposed for EOC that take account of grade of differentiation, histological subtype, and clinical features. However, despite taxonomic efforts, EOC appears to be not a unique disease; its subtypes differ for epidemiological and genetic risk factors, precursor lesions, patterns of spread, response to chemotherapy, and prognosis. Nevertheless, carboplatin plus paclitaxel combination represents the only standard treatment in adjuvant and advanced settings. This paper summarizes theories about the classification and origin of EOC and classical and new prognostic factors. It presents data about standard treatment and novel agents. We speculate about the possibility to create tailored therapy based on specific mutations in ovarian cancer and to personalize prevention.

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.

Clinical potential of mucins in diagnosis, prognosis, and therapy of ovarian cancer

Knowledge of mucins and their multiple roles in various normal and pathological processes has improved greatly in the past two decades. Mucins belong to a family of glycoproteins characterised by densely O-glycosylated repetitive domains and expressed by various surface epithelial cells. Altered expression of mucins is present in various diseases, including cancer. Ovarian cancer is the sixth most common cancer worldwide and the seventh leading cause of cancer-related deaths in women. The most common ovarian cancer is epithelial ovarian carcinoma, which is characterised by few early symptoms, widespread peritoneal dissemination, and ascites at advanced stages that result in poor prognosis. After diagnosis, 5 year survival is only 35-45%. Therefore, improved strategies for early diagnosis and treatment are needed. Because of the surface epithelial origin of epithelial ovarian cancer, mucins are obvious biomolecules for investigation as markers for early diagnosis and as therapeutic targets. We discuss the potential role and clinical usefulness of mucins in early diagnosis, prognosis, and treatment of ovarian cancer.

E-cadherin gene polymorphisms and haplotype associated with the occurrence of epithelial ovarian cancer in Chinese

Backgrounds and aims E-cadherin plays an important role in the origin of epithelial ovarian cancer. However, the exact molecular mechanism by which this occurs is unknown. The polymorphisms located at the E-cadherin may contribute to an increased risk for certain cancers. In this paper, we studied the association between polymorphisms of E-cadherin and the risk of epithelial ovarian cancer. Methods We assessed the − 160C/A, − 347G/GA polymorphism within the promoter region and 3′-UTR + 54C/T polymorphism of E-cadherin in epithelial ovarian cancer and control women. We also tested the expression of E-cadherin protein in ovarian cancer tissue among three genotype (3′-UTR + 54C/T polymorphism) carriers. Results There was no significant difference in genotype distribution of the − 160C/A and − 347G/GA SNPs in the E-cadherin gene promoter region between ovarian cancer patients and controls, but haplotype − 160A/− 347GA relative to haplotype − 160C/− 347G was 48.6 (95% CI = 2.9–806.2) for epithelial ovarian cancer risk. The C/C genotype of the 3′-UTR + 54C/T polymorphism relative to the C/T + T/T genotype was 1.85 (95% CI = 1.27–2.69) for epithelial ovarian cancer risk. E-cadherin protein expression in was lower in C/C genotype carriers than T allele carriers in ovarian cancer tissue ( P = 0.02). Conclusions The C/C genotype of 3′-UTR C/T SNP and − 160C/− 374GA haplotype in E-cadherin gene may be a potential susceptibility factor for risk of epithelial ovarian cancer in Chinese, which indicated that the lower expression of E-cadherin might play an important role in the pathogenesis of epithelial ovarian cancer.

Molecular Targets of Ovarian Carcinomas with Acquired Resistance to Platinum/Taxane Chemotherapy

Ovarian cancer of epithelial origin remains one of the most lethal malignancies despite response rates of more than 80% in first-line combination chemotherapy with platinum drugs and taxanes following surgery. Poor overall prognosis is mainly due to acquired resistance of the recurring tumor mass to initially used and other chemotherapeutic agents. Therefore, novel therapeutic approaches are based on concepts to prevent (improvement of tumor exposure to drugs) or circumvent drug resistance, e.g. with new drugs structurally related to the currently used cytotoxic agents, other types of cytotoxic substances, or with target-specific novel drugs interfering with signaling and apoptotic pathways. In addition, acquired molecular characteristics of drug resistant ovarian carcinoma cells can be defined by expression profiling at different stages of therapy and might be used as specific targets for tumor-suppressing drugs and prodrugs containing cytotoxic components. Revelation of mechanistic details of drug resistance also provides the basis for the development of therapies with novel or conventional antitumor drugs in combination with specific inhibitors able to re-establish chemosensitivity. In this review, we summarize novel approaches in the treatment of ovarian cancer progressed to drug resistant stages and focus on the discussion of recently reported experimental and early clinical results with potentially useful strategies to overcome or modulate acquired drug resistance.

Proteomic analysis of a preneoplastic phenotype in ovarian surface epithelial cells derived from prophylactic oophorectomies

Objective. To study the pattern of protein expression associated with a predisposition to develop ovarian cancer. Methods. Prophylactic oophorectomy is used to prevent ovarian carcinoma in high-risk populations who have a strong family history of breast/ovarian cancer. In ovarian specimens of these women, the ovarian surface epithelium (OSE), which is tissue of origin of epithelial ovarian cancer, often shows altered morphology, growth patterns and differentiation features that are believed to be preneoplastic. This study has used a proteomic approach, based on two-dimensional gel electrophoresis and mass spectrometry, to compare the protein profiles of OSE from women with a history of familial ovarian cancer (FH-OSE), i.e., at least two first-degree relatives with such cancer and/or testing positive for BRCA1 mutations, to those without such history (NFH-OSE). Results. Of >1500 protein spots, there were 8 proteins whose levels were significantly altered in FH-OSE. Three were known ovarian tumor associated proteins, others were novel changes. A number of the alterations seen were accompanied with protein modifications and have not been previously reported. There was a predominance of sequences related to the stress response pathway. Differential expression of selected genes was confirmed by Western blotting and real-time reverse transcription polymerase chain reaction. Conclusions. Our findings define the OSE phenotype of women at a high risk of developing ovarian cancer. Protein alterations seen in these tissues may represent an early, irreversible, non-mutational step in ovarian epithelial neoplastic progression and may be potential early and sensitive markers for the evaluation of cancer risk.