The conceptual advances of carcinogenic sequence model in high-grade serous ovarian cancer

Fallopian tube lesions as potential precursors of early ovarian cancer: a comprehensive proteomic analysis

Ovarian cancer is the leading cause of death from gynecologic cancer worldwide. High-grade serous carcinoma (HGSC) is the most common and deadliest subtype of ovarian cancer. While the origin of ovarian tumors is still debated, it has been suggested that HGSC originates from cells in the fallopian tube epithelium (FTE), specifically the epithelial cells in the region of the tubal-peritoneal junction. Three main lesions, p53 signatures, STILs, and STICs, have been defined based on the immunohistochemistry (IHC) pattern of p53 and Ki67 markers and the architectural alterations of the cells, using the Sectioning and Extensively Examining the Fimbriated End Protocol. In this study, we performed an in-depth proteomic analysis of these pre-neoplastic epithelial lesions guided by mass spectrometry imaging and IHC. We evaluated specific markers related to each preneoplastic lesion. The study identified specific lesion markers, such as CAVIN1, Emilin2, and FBLN5. We also used SpiderMass technology to perform a lipidomic analysis and identified the specific presence of specific lipids signature including dietary Fatty acids precursors in lesions. Our study provides new insights into the molecular mechanisms underlying the progression of ovarian cancer and confirms the fimbria origin of HGSC.

Adipocyte-derived CCDC3 promotes tumorigenesis in epithelial ovarian cancer through the Wnt/ß-catenin signalling pathway

Introduction

Epithelial ovarian cancer (EOC) is a highly aggressive disease whose unique metastatic site is the omentum. Coiled-coil domain containing 3 (CCDC3) is an adipocyte-derived secreted protein that is specifically elevated in omental adipose tissue. However, its function is still unknown.

Material and methods

Initially, a Kaplan-Meier plot was applied to evaluate the prognostic value of CCDC3 expression in patients with EOC. A bioinformatics analysis was next used to explore the biological function of CCDC3 in EOC. Western blot, quantitative real-time polymerase chain reaction, and in vitro invasion and migration assays were performed using SKOV3 cells and CCDC3 secreted by rat adipocytes to analyzes the impact of CCDC3 on EOC and the underlying mechanism.

Results

Overexpression of CCDC3 was associated with poor prognosis of EOC. CCDC3 interacted with multiple key signalling pathways, including the Wnt/β-catenin pathway. EOC cellular proliferation, migration, and invasion were promoted in vitro when co-cultured with CCDC3 enriched conditioned medium, and this tumour-promoting effect was induced by activating the Wnt/β-catenin pathway. Furthermore, the epithelial-mesenchymal transition of EOC cells was reversed after CCDC3 silencing.

Conclusions

Our results support that CCDC3 promotes EOC tumorigenesis through the Wnt/β-catenin pathway and that CCDC3 may serve as a novel prognostic biomarker and therapeutic target for metastatic EOC.

Increased Local Testosterone Levels Alter Human Fallopian Tube mRNA Profile and Signaling

Fallopian tube epithelium (FTE) plays a critical role in reproduction and can be the site where High Grade Serous Ovarian Carcinoma (HGSOC) originates. Tumorigenic oviductal cells, which are the murine equivalent of human fallopian tube secretory epithelial cells (FTSEC), enhance testosterone secretion by the ovary when co-cultured with the ovary, suggesting that testosterone is part of the signaling axis between the ovary and FTSEC. Furthermore, testosterone promotes proliferation of oviductal cells. Oral contraceptives, tubal ligation, and salpingectomy, which are all protective against developing ovarian cancer, also decrease circulating levels of androgen. In the current study, we investigated the effect of increased testosterone on FTE and found that testosterone upregulates wingless-type MMTV integration family, member 4 (WNT4) and induces migration and invasion of immortalized human fallopian tube cells. We profiled primary human fallopian tissues grown in the microfluidic system SOLO-microfluidic platform –(MFP) by RNA sequencing and found that p53 and its downstream target genes, such as paired box gene 2 (PAX2), cyclin-dependent kinase inhibitor 1A (CDK1A or p21), and cluster of differentiation 82 (CD82 or KAI1) were downregulated in response to testosterone treatment. A microfluidic platform, the PREDICT-Multi Organ System (PREDICT-MOS) was engineered to support insert technology that allowed for the study of cancer cell migration and invasion through Matrigel. Using this system, we found that testosterone enhanced FTE migration and invasion, which was reversed by the androgen receptor (AR) antagonist, bicalutamide. Testosterone also enhanced FTSEC adhesion to the ovarian stroma using murine ovaries. Overall, these results indicate that primary human fallopian tube tissue and immortalized FTSEC respond to testosterone to shift expression of genes that regulate invasion, while leveraging a new strategy to study migration in the presence of dynamic fluid flow.

Exploring the clinical value of tumor microenvironment in platinum-resistant ovarian cancer

Platinum resistance in epithelial ovarian cancer (OvCa) is rising at an alarming rate, with recurrence of chemo-resistant high grade serous OvCa (HGSC) in roughly 75 % of all patients. Additionally, HGSC has an abysmal five-year survival rate, standing at 39 % and 17 % for FIGO stages III and IV, respectively. Herein we review the crucial cellular interactions between HGSC cells and the cellular and non-cellular components of the unique peritoneal tumor microenvironment (TME). We highlight the role of the extracellular matrix (ECM), ascitic fluid as well as the mesothelial cells, tumor associated macrophages, neutrophils, adipocytes and fibroblasts in platinum-resistance. Moreover, we underscore the importance of other immune-cell players in conferring resistance, including natural killer cells, myeloid-derived suppressive cells (MDSCs) and T-regulatory cells. We show the clinical relevance of the key platinum-resistant markers and their correlation with the major pathways perturbed in OvCa. In parallel, we discuss the effect of immunotherapies in re-sensitizing platinum-resistant patients to platinum-based drugs. Through detailed analysis of platinum-resistance in HGSC, we hope to advance the development of more effective therapy options for this aggressive disease.

The "Far Left" of the Morphologic Spectrum of Ovarian High-grade Serous Carcinoma: Case Report of a Purely Noninvasive High-grade Serous Carcinoma Mimicking an Ovarian Serous Borderline Tumor

High-grade serous carcinoma has a variety of different growth patterns, but is typically easily recognizable to pathologists and rarely confused with serous borderline tumors. We report a case of a 71-yr-old woman with a unilateral 5.1 cm ovarian cyst with small papillary projections on contrast-enhanced magnetic resonance imaging of the pelvis. Histologic examination showed a noninvasive papillary neoplasm with hierarchical branching and epithelial proliferation, and thus, at low magnification, bearing a striking resemblance to a serous borderline tumor. However, a more careful examination demonstrated high-grade cytologic features, nuclear pleomorphism, and abundant mitotic activity, suggestive of high-grade serous carcinoma. The morphology and immunohistochemical profile of this lesion is consistent with a rare, purely noninvasive growth pattern of high-grade serous carcinoma. This lesion represents the "far left" of the high-grade ovarian serous carcinoma morphologic spectrum and can mimic a serous borderline tumor.

Loss of tubal ciliated cells as a risk for "ovarian" or pelvic serous carcinoma

Recent advances suggest the fallopian tube as the main anatomic site for high-grade ovarian or pelvic serous carcinoma (O/PSC). Many studies on the biologic role of tubal secretory cells in O/PSC development has been performed in the last decade. However, the role of tubal ciliated cells in this regard has rarely been explored. The purpose of this study was to determine if the change of the tubal ciliated cells is associated with serous neoplasia within the female pelvis. This study included 3 groups (low-risk or benign control, high-risk, and O/PSC) of patients and they were age-matched. Age of patients ranged from 20 to 85 and the age-associated data was stratified by 10-year intervals. The number of tubal ciliated cells was determined by microscopy and by tubulin immunohistochemical staining. The data was then professionally analyzed. The results showed that the absolute number of tubal ciliated cells decreased significantly with age within each age group. A reduction in ciliated cell counts within the tubal segments remained a significant risk factor for the development of serous cancers within the female pelvis after age adjustment. A dramatic decrease of tubal ciliated cells was identified in patients with high-risk and with O/PSC compared to those in the benign control or low-risk group (P < 0.001). Further, within the tubal fimbria, the number of ciliated cells reduction was more prominent in the high-risk group when compared to those of O/PSC patients. Our findings suggest that a decreased number of ciliated cells within women's fallopian tubes represents another histologic hallmark for early serous carcinogenesis. There is a relationship between loss of tubal ciliated cells and aging, the presence of high-risk factors for tubal-ovarian cancer, and co-existing O/PSCs. This represents an initial study identifying the role of tubal ciliated cells in the development of high-grade serous carcinoma in women's pelvis.

Reduced PAX2 expression in murine fallopian tube cells enhances estrogen receptor signaling

High-grade serous ovarian cancer (HGSOC) is thought to progress from a series of precursor lesions in the fallopian tube epithelium (FTE). One of the preneoplastic lesions found in the FTE is called a secretory cell outgrowth (SCOUT), which is partially defined by a loss of paired box 2 (PAX2). In the present study, we developed PAX2-deficient murine cell lines in order to model a SCOUT and to explore the role of PAX2 loss in the etiology of HGSOC. Loss of PAX2 alone in the murine oviductal epithelium (MOE) did not induce changes in proliferation, migration and survival in hypoxia or contribute to resistance to first line therapies, such as cisplatin or paclitaxel. RNA sequencing of MOE PAX2shRNA cells revealed significant alterations in the transcriptome. Silencing of PAX2 in MOE cells produced a messenger RNA expression pattern that recapitulated several aspects of the transcriptome of previously characterized human SCOUTs. RNA-seq analysis and subsequent qPCR validation of this SCOUT model revealed an enrichment of genes involved in estrogen signaling and an increase in expression of estrogen receptor α. MOE PAX2shRNA cells had higher estrogen signaling activity and higher expression of putative estrogen responsive genes both in the presence and absence of exogenous estrogen. In summary, loss of PAX2 in MOE cells is sufficient to transcriptionally recapitulate a human SCOUT, and this model revealed an enrichment of estrogen signaling as a possible route for tumor progression of precursor lesions in the fallopian tube.

Fallopian Tube Epithelial Changes in Ovarian Serous Tumors Compared with Control Group: A Single-Center Study

BACKGROUND

Recent studies have hypothesized that distal end of fallopian tube is a possible origin of ovarian serous carcinoma. This study investigated histopathological changes in fallopian tube epithelium (FTE) of the patients with ovarian serous tumors compared with control group.

MATERIALS AND METHODS

In a prospective cross-sectional study, fallopian tubes (right and left) of 34 cases with ovarian serous tumors were collected from patients who underwent surgery in two major gynecological centers affiliated to Shiraz University of Medical Sciences, Shiraz, Iran (2012-2015). They are composed of 21 (61.8%) high-grade serous carcinomas (HGSCs), 5 (14.7%) borderline ones, and 8 (23.5%) benign serous tumors. As control group, fallopian tubes of 72 hystrectomy cases without ovarian tumor were added to the study. Both tubes of all of the cases were submitted entirely, according to the protocol of sectioning and extensively examining the fimbriated end. The results were statistically analyzed using SPSS-PC windows and Chi-square tests.

RESULTS

Significant differences were found between the cases and control group in tubal epithelial cell stratification (especially >3 cell layers thickness), atypia, mitosis, glandular complexity, tufting, and detached epithelial cells (P < 0.05). These findings particularly atypia and mitosis were more frequently seen in the ampulla and fimbriated end of high-grade ovarian serous carcinomas.

CONCLUSION

Our results showed that premalignant epithelial changes of the ampulla and the distal end of FTE were seen in some of the patients with ovarian HGSCs. Therefore, FTE could be one of the sources of ovarian serous carcinoma.

Precancer in ulcerative colitis: the role of the field effect and its clinical implications

Cumulative evidence indicates that a significant proportion of cancer evolution may occur before the development of histological abnormalities. While recent improvements in DNA sequencing technology have begun to reveal the presence of these early preneoplastic clones, the concept of 'premalignant field' was already introduced by Slaughter more than half a century ago. Also referred to as 'field effect', 'field defect' or 'field cancerization', these terms describe the phenomenon by which molecular alterations develop in normal-appearing tissue and expand to form premalignant patches with the potential to progress to dysplasia and cancer. Field effects have been well-characterized in ulcerative colitis, an inflammatory bowel disease that increases the risk of colorectal cancer. The study of the molecular alterations that define these fields is informative of mechanisms of tumor initiation and progression and has provided potential targets for early cancer detection. Herein, we summarize the current knowledge about the molecular alterations that comprise the field effect in ulcerative colitis and the clinical utility of these fields for cancer screening and prevention.

Revisiting ovarian cancer microenvironment: a friend or a foe?

Development of ovarian cancer involves the co-evolution of neoplastic cells together with the adjacent microenvironment. Steps of malignant progression including primary tumor outgrowth, therapeutic resistance, and distant metastasis are not determined solely by genetic alterations in ovarian cancer cells, but considerably shaped by the fitness advantage conferred by benign components in the ovarian stroma. As the dynamic cancer topography varies drastically during disease progression, heterologous cell types within the tumor microenvironment (TME) can actively determine the pathological track of ovarian cancer. Resembling many other solid tumor types, ovarian malignancy is nurtured by a TME whose dark side may have been overlooked, rather than overestimated. Further, harnessing breakthrough and targeting cures in human ovarian cancer requires insightful understanding of the merits and drawbacks of current treatment modalities, which mainly target transformed cells. Thus, designing novel and precise strategies that both eliminate cancer cells and manipulate the TME is increasingly recognized as a rational avenue to improve therapeutic outcome and prevent disease deterioration of ovarian cancer patients.