Progesterone Prevents High-Grade Serous Ovarian Cancer by Inducing Necroptosis of p53-Defective Fallopian Tube Epithelial Cells

Unveiling drug resistance pathways in high-grade serous ovarian cancer(HGSOC): recent advances and future perspectives

High-Grade Serous Ovarian Carcinoma (HGSOC) represents the most prevalent and lethal subtype of ovarian cancer, with approximately 225,000 new cases reported globally each year and a five-year survival rate of merely 49.1%. The clinical management of HGSOC encounters substantial challenges, primarily attributable to its intricate drug resistance mechanisms, which involve multiple biological processes, including tumor cell heterogeneity, microenvironment remodeling, gene mutations, and drug efflux. This study systematically reviews the most recent advancements in HGSOC drug resistance research, concentrating on the molecular biological foundations of resistance mechanisms, innovative detection strategies, and potential therapeutic approaches. The research indicates that HGSOC drug resistance constitutes a complex process characterized by multifactorial interactions, involving aberrant cell signaling pathways, dynamic alterations in the tumor microenvironment, and specific expressions of molecular markers. In this review, we systematically analyzed and investigated the intricate biological behaviors associated with HGSOC drug resistance, which not only enhances the understanding of disease progression but also provides essential theoretical foundations for the development of more precise and effective targeted therapies. This review firstly illustrated the detailed drug resistance cellular and molecular mechanisms underlying HGSOC chemotherapy, which can pave the way for future studies in HGSOC drug resistance practices.

Oral contraceptive use is associated with a reduction in the physical size of fallopian tube p53 signatures

OBJECTIVE

Oral contraceptives reduce ovarian cancer risk, but the mechanism of risk reduction is not understood. We examined whether oral contraceptive pill (OCP) use influences p53 signatures, which are putative early fallopian tube precursors for high-grade serous ovarian carcinomas.

METHODS

For this retrospective cohort (n = 250) of subjects aged over 50 years who had fallopian tubes removed at the time of a benign gynecologic procedure, we used health records to identify 72 patients who used OCPs for at least 5 years and 178 subjects with no history of OCP use. Immunohistochemistry for p53 was performed on all fallopian tube sections, with 8 individuals removed for lack of identifiable tissue. p53 Signatures were identified and stratified based on size. Logistic regressions were run to estimate the association between OCP use and p53 lesion and lesion size.

RESULTS

There was no difference in the occurrence of p53 lesions with 20 of 70 of OCP users (28.6%) and 57 of 172 of those with no history of OCP use (33.1%). Subjects who used OCPs were more likely to have a small lesion (OR 1.98, 95% CI 1.03 to 3.83) and had decreased risk of having a medium/large lesion (OR 0.38, 95% CI 0.18 to 0.79). A total of 2 serous tubal intraepithelial lesions and 2 serous tubal intraepithelial carcinomas were identified in OCP-naive patients, whereas none were found in those with a history of OCP use.

CONCLUSIONS

OCP exposure was associated with a shift toward smaller p53 lesion size but was not found to be associated with a difference in the number of p53 lesions between OCP-exposed and unexposed patients. Future research should examine whether OCP use reduces proliferation and clonal expansion of p53 signature lesions toward higher risk precursors and, eventually, cancer. There were no serous tubal intraepithelial lesions and serous tubal intraepithelial carcinomas in patients with OCP exposure.

Necroptosis-Related Gene Signature Predicts Prognosis in Patients with Advanced Ovarian Cancer

Background/Objectives: This study aimed to construct a risk score (RS) based on necroptosis-associated genes to predict the prognosis of patients with advanced epithelial ovarian cancer (EOC). Methods: EOC data from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) series 140082 (GSE140082) were used. Based on known necroptosis-associated genes, clustering was performed to identify molecular subtypes of EOC. A least absolute shrinkage and selection operator (LASSO)-Cox regression analysis identified key genes related to prognosis. The expression of one of them, RIPK3, was analyzed via immunohistochemistry in an EOC cohort. Results: An RS made from ten genes (IDH2, RIPK3, FASLG, BRAF, ITPK1, TNFSF10, ID1, PLK1, MLKL and HSPA4) was developed. Tumor samples were divided into a high-risk group (HRG) and low-risk group (LRG) using the RS. The model is able to predict the overall survival (OS) of EOC and distinguish the prognosis of different clinical subgroups. Immunohistochemical verification of the receptor-interacting serine/threonine-protein kinase (RIPK) 3 confirmed that high nuclear expression is correlated with a longer OS. In addition, the score can predict the response to a programmed death ligand 1 (PD-L1) blockade treatment in selected solid malignancies. Patients from the LRG seem to benefit more from it than patients from the HRG. Conclusions: Our RS based on necroptosis-associated genes might help to predict the prognosis of patients with advanced EOC and gives an idea on how the use of immunotherapy can potentially be guided.

Ovulation sources ROS to confer mutagenic activities on the TP53 gene in the fallopian tube epithelium

INTRODUCTION

Epidemiological studies have implicated ovulation as a risk factor for ovarian high-grade serous carcinoma (HGSC) at the initiation stage. Precancerous lesions of HGSC commonly exhibit TP53 mutations attributed to DNA deamination and are frequently localized in the fallopian tube epithelium (FTE), a site regularly exposed to ovulatory follicular fluid (FF). This study aimed to assess the mutagenic potential of FF and investigate the expression levels and functional role of activation-induced cytidine deaminase (AID) following ovulation, along with the resulting TP53 DNA deamination.

METHODS

The mutagenic activity of FF toward premalignant and malignant FTE cells was determined using the hypoxanthine phosphoribosyl transferase (HPRT) mutation assay with or without AID knockdown. The sequential activation of AID, including expressional induction, nuclear localization, DNA binding, and deamination, was determined. AID inducers in FF were identified, and the times of action and signaling pathways were determined.

RESULTS

FF induced AID activation and de novo FTE cell mutagenesis in two waves of activity in accordance with post-ovulation FF exposure. The ERK-mediated early activity started at 2 min and peaked at 45 min, and the NF-κB-mediated late activity started at 6 h and peaked at 8.5 h after exposure. ROS, TNF-α, and estradiol, which are abundant in FF, all induced the two activities, while all activities were abolished by antioxidant cotreatment. AID physically bound to and biochemically deaminated the TP53 gene, regardless of known mutational hotspots. It did not act on other prevalent tumor-suppressor genes of HGSC.

CONCLUSION

This study revealed the ROS-dependent AID-mediated mutagenic activity of the ovulatory FF. The results filled up the missing link between ovulation and the initial TP53 mutation and invited a strategy of antioxidation in prevention of HGSC.

From fallopian tube epithelium to high-grade serous ovarian cancer: A single-cell resolution review of sex steroid hormone signaling

High-grade serous ovarian cancer (HGSOC) represents the most lethal subtype of ovarian cancer, largely due to being commonly diagnosed at advanced stages. The early molecular mechanisms underlying ovarian carcinogenesis remain poorly defined, posing challenges to the development of prevention and early detection strategies. Here we dissect the molecular mechanisms of sex steroid hormone signaling throughout the decades-long evolution of HGSOC precursor lesions, which predominantly originate from secretory epithelial cells of fallopian tubes (FT). We also discuss the prognostic significance of sex steroid receptor isoforms and steroid metabolizing enzymes in HGSOCs. Finally, we provide a comprehensive gene expression atlases of sex steroid receptors, steroidogenic, and steroid-metabolizing enzymes across different cell populations in pre- and postmenopausal FTs, and HGSOCs, using published single-cell RNA sequencing datasets. These atlases reveal that secretory epithelial cells and stromal populations in FTs express sex steroid receptors and enzymes responsible for the formation and inactivation of genotoxic estrogen metabolites. In HGSOC, epithelial cells express various HSD17B isoforms and steroid conjugating enzymes, suggesting an enhanced ability to finely regulate the levels of bioactive sex steroids.

The romantic history of signaling pathway discovery in cell death: an updated review

Cell death is a fundamental physiological process in all living organisms. Processes such as embryonic development, organ formation, tissue growth, organismal immunity, and drug response are accompanied by cell death. In recent years with the development of electron microscopy as well as biological techniques, especially the discovery of novel death modes such as ferroptosis, cuprotosis, alkaliptosis, oxeiptosis, and disulfidptosis, researchers have been promoted to have a deeper understanding of cell death modes. In this systematic review, we examined the current understanding of modes of cell death, including the recently discovered novel death modes. Our analysis highlights the common and unique pathways of these death modes, as well as their impact on surrounding cells and the organism as a whole. Our aim was to provide a comprehensive overview of the current state of research on cell death, with a focus on identifying gaps in our knowledge and opportunities for future investigation. We also presented a new insight for macroscopic intracellular survival patterns, namely that intracellular molecular homeostasis is central to the balance of different cell death modes, and this viewpoint can be well justified by the signaling crosstalk of different death modes. These concepts can facilitate the future research about cell death in clinical diagnosis, drug development, and therapeutic modalities.

Gender differences in gliomas: From epidemiological trends to changes at the hormonal and molecular levels

Gender plays a crucial role in the occurrence and development of cancer, as well as in the metabolism of nutrients and energy. Men and women display significant differences in the incidence, prognosis, and treatment response across various types of cancer, including certain sex-specific tumors. It has been observed that male glioma patients have a higher incidence and worse prognosis than female patients, but there is currently a limited systematic evaluation of sex differences in gliomas. The purpose of this study is to provide an overview of the association between fluctuations in sex hormone levels and changes in their receptor expression with the incidence, progression, treatment, and prognosis of gliomas. Estrogen may have a protective effect on glioma patients, while exposure to androgens increases the risk of glioma. We also discussed the specific genetic and molecular differences between genders in terms of the malignant nature and prognosis of gliomas. Factors such as TP53, MGMT methylation status may play a crucial role. Therefore, it is essential to consider the gender of patients while treating glioma, particularly the differences at the hormonal and molecular levels. This approach can help in the adoption of an individualized treatment strategy.

Progesterone Enhances Niraparib Efficacy in Ovarian Cancer by Promoting Palmitoleic-Acid-Mediated Ferroptosis

Poly (adenosine 5'-diphosphate-ribose) polymerase inhibitors (PARPi) are increasingly important in the treatment of ovarian cancer. However, more than 40% of BRCA1/2-deficient patients do not respond to PARPi, and BRCA wild-type cases do not show obvious benefit. In this study, we demonstrated that progesterone acted synergistically with niraparib in ovarian cancer cells by enhancing niraparib-mediated DNA damage and death regardless of BRCA status. This synergy was validated in an ovarian cancer organoid model and in vivo experiments. Furthermore, we found that progesterone enhances the activity of niraparib in ovarian cancer through inducing ferroptosis by up-regulating palmitoleic acid and causing mitochondrial damage. In clinical cohort, it was observed that progesterone prolonged the survival of patients with ovarian cancer receiving PARPi as second-line maintenance therapy, and high progesterone receptor expression combined with low glutathione peroxidase 4 (GPX4) expression predicted better efficacy of PARPi in patients with ovarian cancer. These findings not only offer new therapeutic strategies for PARPi poor response ovarian cancer but also provide potential molecular markers for predicting the PARPi efficacy.

Possible role of apelin on the ovarian steroidogenesis and uterine apoptosis of infantile mice: An in vitro study

The expression of adipokines is well-known in the ovary and uterus. Recently we have shown that apelin and its receptor, APJ are developmentally regulated in the ovary and uterus of mice with elevation at postnatal day 14 (PND14). However, its role in the ovary and uterus of PND14 has not been investigated. Thus, we aimed to unravel the role of the apelin system (by APJ antagonist, ML221) on ovarian steroid secretion, proliferation, and apoptosis along with its role in uterine apoptosis in PND14 mice by in vitro approaches. The treatment of ML221 decreased estrogen, testosterone, and androstenedione secretion while increasing the progesterone secretion from the infantile ovary. These results suggest that apelin signaling would be important for ovarian estrogen synthesis in infantile mice (PND14). The abundance of 3β-HSD, 17β-HSD, aromatase, and active caspase3 increased in the infantile ovary after ML221 treatment. The expression of ERs and BCL2 were also down-regulated by ML221 treatment. The decreased BCL2 and increased active caspase3 by ML221 suggest the suppressive role of apelin on ovarian apoptosis. The APJ antagonist treatment also down-regulated the ER expression in the uterus along with increased active caspase3 and decreased BCL2 expression. In conclusion, apelin signaling inhibits the ovarian and uterine apoptosis via estrogen signaling in the ovary and uterus.

The role of non-genomic actions of progesterone and its membrane receptor agonist in ovarian cancer cell death

BACKGROUND

Progesterone therapy is a relatively inexpensive treatment option for endometrial and breast cancers, with few side effects. Two signaling pathways usually mediate the physiological effects of progesterone, namely genomic and non-genomic actions. Genomic action occurs slowly via the nuclear progesterone receptor (PR), whereas the membrane progesterone receptor (mPR) induces rapid non-genomic action.

AIMS

We investigated the effects of progesterone and various PR agonists on ovarian cancer cells.

METHODS AND RESULTS

PR expression of six serous ovarian cancer cell lines was examined by western blotting, and mPR expression was examined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). PR-negative and mPR-positive ovarian cancer cells were exposed to progesterone and seven types of PR agonists (medroxyprogesterone acetate [MPA], dehydroepiandrosterone, dienogest, levonorgestrel, drospirenone, pregnenolone, and allopregnanolone) at 10-400 μM, and viable cell counts after exposure for 30 min were measured using the water-soluble tetrazolium (WST-1) assay. Ovarian cancer cell lines were exposed to 100 μM progesterone, and the expression of BAX, a pro-apoptotic protein, after 1-5 min was examined by western blotting. Western blotting detected no PR expression in the six serous ovarian cancer cell lines. In contrast, RT-qPCR detected mPR expression in all six serous ovarian cancer cell lines. Progesterone and MPA-induced cell death in all tested ovarian cancer cell lines in a concentration-dependent manner, whereas no effect was observed for other PR agonists. Western blotting revealed that pro-apoptotic protein BAX expression occurred 1 min after exposure to progesterone, suggesting that the cytocidal effects are mediated by rapid non-genomic action.

CONCLUSION

Progesterone and MPA exhibited a rapid cytocidal effect on PR-negative ovarian cancer cells through non-genomic action. Progesterone and MPA could be novel adjuvant therapies for ovarian cancer.

Reevaluating the Role of Progesterone in Ovarian Cancer: Is Progesterone Always Protective?

Ovarian cancer (OC) represents a collection of rare but lethal gynecologic cancers where the difficulty of early detection due to an often-subtle range of abdominal symptoms contributes to high fatality rates. With the exception of BRCA1/2 mutation carriers, OC most often manifests as a post-menopausal disease, a time in which the ovaries regress and circulating reproductive hormones diminish. Progesterone is thought to be a "protective" hormone that counters the proliferative actions of estrogen, as can be observed in the uterus or breast. Like other steroid hormone receptor family members, the transcriptional activity of the nuclear progesterone receptor (nPR) may be ligand dependent or independent and is fully integrated with other ubiquitous cell signaling pathways often altered in cancers. Emerging evidence in OC models challenges the singular protective role of progesterone/nPR. Herein, we integrate the historical perspective of progesterone on OC development and progression with exciting new research findings and critical interpretations to help paint a broader picture of the role of progesterone and nPR signaling in OC. We hope to alleviate some of the controversy around the role of progesterone and give insight into the importance of nPR actions in disease progression. A new perspective on the role of progesterone and nPR signaling integration will raise awareness to the complexity of nPRs and nPR-driven gene regulation in OC, help to reveal novel biomarkers, and lend critical knowledge for the development of better therapeutic strategies.

An epigenetic hypothesis for ovarian cancer prevention by oral contraceptive pill use

BACKGROUND

Ovarian cancer is the second most common gynecological cancer type after uterine cancers. In 2020, according to worldwide statistics, there were more than 313,000 new cases of ovarian cancer. Most concerning with ovarian cancer is the poor overall survival, with only 30% of patients surviving for longer than 5 years after diagnosis. The reason for this poor outcome includes late diagnosis due to non-specific symptoms and a lack of any highly effective biomarkers of the early stages of ovarian carcinogenesis. However, it is important to note that some modifiable lifestyle factors can be preventative [pregnancy, breastfeeding and combined oral contraceptives pill (COCP) use].

RESULTS

There is now increasing data reporting the role of epigenetic changes, which are detectable in ovarian cancer tumors, suggesting the possibility that epigenetics may also play a key role in the mechanism of long-term effective prevention of ovarian cancer. To our knowledge, there is a lack of high-quality data on the molecular mechanisms of ovarian cancer prevention, although several hypotheses have been proposed.

CONCLUSIONS

This review focusses on the evidence for a proposed novel hypothesis-that COCPs act as a chemoprevention through the impact on the epigenome of the cells of origin of ovarian cancer-fallopian tubes epithelium.

Necroptosis-related regulatory pattern and scoring system for predicting therapeutic efficacy and prognosis in ovarian cancer

BACKGROUND

Ovarian cancer is difficult to treat and is, therefore, associated with a high fatality rate. Although targeted therapy and immunotherapy have been successfully used clinically to improve the diagnosis and treatment of ovarian cancer, most tumors become drug resistant, and patients experience relapse, meaning that the overall survival rate remains low.

AIMS

There is currently a lack of effective biomarkers for predicting the prognosis and/or outcomes of patients with ovarian cancer. Therefore, we used published transcriptomic data derived from a large ovarian cancer sample set to establish a molecular subtyping model of the core genes involved in necroptosis in ovarian cancer.

METHODS AND RESULTS

Clustering analysis and differential gene expression analyses were performed to establish the genomic subtypes related to necroptosis and to explore the patterns of regulatory gene expression related to necroptosis in ovarian cancer. A necroptosis scoring system (NSS) was established using principal component analysis according to different regulatory patterns of necroptosis. In addition, this study revealed important biological processes with essential roles in the regulation of ovarian tumorigenesis, including external encapsulating structure organization, leukocyte migration, oxidative phosphorylation, and focal adhesion. Patients with high NSS scores had unique immunophenotypes, such as more abundant M2 macrophages, monocytes, CD4+ memory T cells, and regulatory T cells. Immune checkpoint CD274 had a greater expression in patients with high NSS values.

CONCLUSION

This NSS could be used as an independent predictor of prognosis to determine the sensitivity of ovarian cancer to various small-molecule inhibitors, immune checkpoint inhibitors, and platinum-based chemotherapy drugs.

An updated review of a novel method for examining P53 mutations in different forms of cancer

In the past fifteen years, it has been clear that tumor-associated p53 mutations can cause behaviors distinct from those brought on by a simple loss of p53's tumor-suppressive function in its wild-type form. Many of these mutant p53 proteins develop oncogenic characteristics that allow them to encourage cell survival, invasion, and metastasis. But it is now understood that the immune response is also significantly influenced by the cancer cell's p53 status. The recruitment and activity of myeloid and T cells can be impacted by p53 loss or mutation in malignancies, allowing immune evasion and accelerating cancer growth. Additionally, p53 can work in immune cells, which can have various effects that either hinder or assist the growth of tumors. In this review article, we examined different mutations of P53 in some significant cancers, such as liver, colorectal, and prostate, and reviewed some new therapeutic approaches.

Hormone Receptors and Epithelial Ovarian Cancer: Recent Advances in Biology and Treatment Options

Epithelial ovarian cancer (EOC) is a significant cause of cancer-related mortality in women. Despite advances in diagnosis and treatment, EOC remains a challenging disease to manage, and the 5-year survival rate is still poor. The role of hormone receptors (HRs) in EOC carcinogenesis and prognosis has been actively explored; however, the role of hormone therapy (HT) in the treatment of these tumors is not well established. Most available data on HT mainly come from retrospective series and small early clinical trials. Several of these studies suggest that HT may have a role in adjuvant, maintenance therapy, or in the case of recurrent disease, especially for some subtypes of EOC (e.g., low-grade serous EOC). Furthermore, HT has recently been combined with targeted therapies, but most studies evaluating these combinations are still ongoing. The main aim of this review is to provide an overview of the progress made in the last decade to characterize the biological and prognostic role of HRs for EOC and the developments in their therapeutic targeting through HT.

Effects of the Overexpression of Progesterone Receptors on a Precancer p53 and Rb-Defective Human Fallopian Tube Epithelial Cell Line

This study investigated the effects of progesterone receptors A (PRA) and B (PRB) on proliferation, migration, invasion, anchorage-independent growth (AIG), and apoptosis of FE25 cells, a precancer p53- and retinoblastoma-defective human fallopian tube epithelial cell line. We observed that the transfection of PRA (FE25-PRA) or PRB (FE25-PRB) into FE25 cells significantly increased the expression of PRA or PRB at both RNA and protein levels without affecting cell morphology. The FE25-PRA cells exhibited slower proliferation, whereas FE25-PRB showed faster cell proliferation than the control cells. In contrast, the FE25-PRA cells showed the highest migration and invasion abilities, whereas the FE25-PRB cells showed the lowest migration and invasion abilities. After treatment with progesterone, all cell types showed decreased AIG levels, increased apoptotic rates in Terminal deoxynucleotidyl transferase (TdT) dUTP nick end labeling assay (TUNEL) staining, and increased levels of apoptotic proteins ascertained based on cleaved caspase-3 levels. The half-maximal inhibitory concentration of carboplatin increased in FE25-PRB cells, but that of paclitaxel remained unchanged. Overall, this study suggests that PRA and PRB have distinct roles in regulating the behavior of FE25 cells, and targeting these receptors could be a potential therapeutic strategy for ovarian cancer treatment. If PRA or PRB overexpression is observed in high-grade serous carcinoma, progesterone could be considered as an adjuvant therapy for these specific cancer patients. However, further research is needed to confirm these findings and investigate the mechanisms underlying these effects.

Crosstalk between ferroptosis and steroid hormone signaling in gynecologic cancers

Ferroptosis is a novel types of regulated cell death and is widely studied in cancers and many other diseases in recent years. It is characterized by iron accumulation and intense lipid peroxidation that ultimately inducing oxidative damage. So far, signaling pathways related to ferroptosis are involved in all aspects of determining cell fate, including oxidative phosphorylation, metal-ion transport, energy metabolism and cholesterol synthesis progress, et al. Recently, accumulated studies have demonstrated that ferroptosis is associated with gynecological oncology related to steroid hormone signaling. This review trends to summarize the mechanisms and applications of ferroptosis in cancers related to estrogen and progesterone, which is expected to provide a theoretical basis for the prevention and treatment of gynecologic cancers.

Dichotomous ovarian cancer-initiating potential of Pax8+ cells revealed by a mouse genetic mosaic model

Different cellular compartments within a tissue present distinct cancer-initiating capacities. Current approaches to dissect such heterogeneity require cell-type-specific genetic tools based on a well-understood lineage hierarchy, which are lacking for many tissues. Here, we circumvented this hurdle and revealed the dichotomous capacity of fallopian tube Pax8+ cells in initiating ovarian cancer, utilizing a mouse genetic system that stochastically generates rare GFP-labeled mutant cells. Through clonal analysis and spatial profiling, we determined that only clones founded by rare, stem/progenitor-like Pax8+ cells can expand on acquiring oncogenic mutations whereas vast majority of clones stall immediately. Furthermore, expanded mutant clones undergo further attrition: many turn quiescent shortly after the initial expansion, whereas others sustain proliferation and manifest a bias toward Pax8+ fate, underlying early pathogenesis. Our study showcases the power of genetic mosaic system-based clonal analysis for revealing cellular heterogeneity of cancer-initiating capacity in tissues with limited prior knowledge of lineage hierarchy.

Search for New Participants in the Pathogenesis of High-Grade Serous Ovarian Cancer with the Potential to Be Used as Diagnostic Molecules

Recent studies have attempted to develop molecular signatures of epithelial ovarian cancer (EOC) based on the quantitation of protein-coding and non-coding RNAs to predict disease prognosis. Due to the heterogeneity of EOC, none of the developed prognostic signatures were directly applied in clinical practice. Our work focuses on high-grade serous ovarian carcinoma (HGSOC) due to the highest mortality rate relative to other types of EOC. Using deep sequencing of small non-coding RNAs in combination with quantitative real-time PCR, we confirm the dualistic classification of epithelial ovarian cancers based on the miRNA signature of HGSOC (type 2), which differs from benign cystadenoma and borderline cystadenoma-precursors of low-grade serous ovarian carcinoma (type 1)-and identified two subtypes of HGSOC, which significantly differ in the level of expression of the progesterone receptor in the tumor tissue, the secretion of miR-16-5p, miR-17-5p, miR-93-5p, miR-20a-5p, the level of serum CA125, tumor size, surgical outcome (optimal or suboptimal cytoreduction), and response to chemotherapy. It was found that the combined determination of the level of miR-16-5p, miR-17-5p, miR-20a-5p, and miR-93-5p circulating in blood plasma of patients with primary HGSOC tumors makes it possible to predict optimal cytoreduction with 80.1% sensitivity and 70% specificity (p = 0.022, TPR = 0.8, FPR = 0.3), as well as complete response to adjuvant chemotherapy with 77.8% sensitivity and 90.9% specificity (p = 0.001, TPR = 0.78, FPR = 0.09). After the additional verification of the obtained data in a larger HGSOC patient cohort, the combined quantification of these four miRNAs is proposed to be used as a criterion for selecting patients either for primary cytoreduction or neoadjuvant chemotherapy followed by interval cytoreduction.

Current insights into the regulation of programmed cell death by TP53 mutation in cancer

Gene mutation is a complicated process that influences the onset and progression of cancer, and the most prevalent mutation involves the TP53 gene. One of the ways in which the body maintains homeostasis is programmed cell death, which includes apoptosis, autophagic cell death, pyroptosis, ferroptosis, NETosis, and the more recently identified process of cuprotosis. Evasion of these cell deaths is a hallmark of cancer cells, and our elucidation of the way these cells die helps us better understands the mechanisms by which cancer arises and provides us with more ways to treat it.Studies have shown that programmed cell death requires wild-type p53 protein and that mutations of TP53 can affect these modes of programmed cell death. For example, mutant p53 promotes iron-dependent cell death in ferroptosis and inhibits apoptotic and autophagic cell death. It is clear that TP53 mutations act on more than one pathway to death, and these pathways to death do not operate in isolation. They interact with each other and together determine cell death. This review focuses on the mechanisms via which TP53 mutation affects programmed cell death. Clinical investigations of TP53 mutation and the potential for targeted pharmacological agents that can be used to treat cancer are discussed.

Ferroptosis, necroptosis, and pyroptosis in the occurrence and development of ovarian cancer

Ovarian cancer (OC) is one of the most common malignancies that causes death in women and is a heterogeneous disease with complex molecular and genetic changes. Because of the relatively high recurrence rate of OC, it is crucial to understand the associated mechanisms of drug resistance and to discover potential target for rational targeted therapy. Cell death is a genetically determined process. Active and orderly cell death is prevalent during the development of living organisms and plays a critical role in regulating life homeostasis. Ferroptosis, a novel type of cell death discovered in recent years, is distinct from apoptosis and necrosis and is mainly caused by the imbalance between the production and degradation of intracellular lipid reactive oxygen species triggered by increased iron content. Necroptosis is a regulated non-cysteine protease–dependent programmed cell necrosis, morphologically exhibiting the same features as necrosis and occurring via a unique mechanism of programmed cell death different from the apoptotic signaling pathway. Pyroptosis is a form of programmed cell death that is characterized by the formation of membrane pores and subsequent cell lysis as well as release of pro-inflammatory cell contents mediated by the abscisin family. Studies have shown that ferroptosis, necroptosis, and pyroptosis are involved in the development and progression of a variety of diseases, including tumors. In this review, we summarized the recent advances in ferroptosis, necroptosis, and pyroptosis in the occurrence, development, and therapeutic potential of OC.

Progesterone limits the tumor-promoting effects of the beta-subunit of human chorionic gonadotropin via non-nuclear receptors

The post-menopausal state in women is associated with increased cancer incidence, the reasons for which remain obscure. Curiously, increased circulating levels of beta-hCG (human chorionic gonadotropin) (a hormonal subunit linked with tumors of several lineages) are also often observed post-menopause. This study describes a previously unidentified interplay between beta-hCG and progesterone in tumorigenesis. Progesterone mediated apoptosis in beta-hCG responsive tumor cells via non-nuclear receptors. The transgenic expression of beta-hCG, particularly in the absence of the ovaries (a mimic of the post-menopausal state) constituted a potent pro-tumorigenic signal. Significantly, the administration of progesterone had significant anti-tumor effects. RNA-seq profiling identified molecular signatures associated with these processes. TCGA analysis revealed correlates between the expression of several newly identified genes and poor prognosis in post-menopausal patients of lung adenocarcinoma, colon adenocarcinoma, and glioblastoma. Specifically in these women, the detection of intra-tumoral/extra-tumoral beta-hCG may serve as a useful prognostic indicator, and treatment with progesterone on its detection may prove beneficial.

Beyond the pill: contraception and the prevention of hereditary ovarian cancer

BRCA1 and BRCA2 mutation carriers face an elevated lifetime risk of developing ovarian cancer. Oral contraceptives have been shown to significantly decrease the risk of ovarian cancer by approximately 50% in this high-risk population. Changes in contraceptive formulations and patterns of use over time have introduced lower hormonal dosages, different steroid types and non-oral routes of administration. Specifically, there has been a considerable shift in patterns of contraceptive use and the increase in the uptake of non-oral, long-acting, reversible contraception (e.g., intrauterine devices, implants, injections) has corresponded to a decline in oral contraceptive pill use. Whether or not these other methods confer a protective effect against ovarian cancer in the general population is not clear. To our knowledge, there have been no such studies conducted among BRCA mutation carriers. Furthermore, the impact of these changes on the risk of developing ovarian cancer is not known. In this article, we will review the existing epidemiologic evidence regarding the role of contraceptives and the risk of ovarian cancer with a focus on women with a BRCA1 or BRCA2 mutation. We will discuss recent findings and gaps in the knowledge while extrapolating from studies conducted among women from the noncarrier population.

Non-apoptotic cell death in ovarian cancer: Treatment, resistance and prognosis

Ovarian cancer is mostly diagnosed at an advanced stage due to the absence of effective screening methods and specific symptoms. Repeated chemotherapy resistance and recurrence before PARPi are used as maintenance therapies, lead to low survival rates and poor prognosis. Apoptotic cell death plays a crucial role in ovarian cancer, which is proved by current researches. With the ongoing development of targeted therapy, non-apoptotic cell death has shown substantial potential in tumor prevention and treatment, including autophagy, ferroptosis, necroptosis, immunogenic cell death, pyroptosis, alkaliptosis, and other modes of cell death. We systematically reviewed the research progress on the role of non-apoptotic cell death in the onset, development, and outcome of ovarian cancer. This review provides a more theoretical basis for exploring therapeutic targets, reversing drug resistance in refractory ovarian cancer, and establishing risk prediction models that help realize the clinical transformation of vital drugs.

Liver Receptor homolog-1 Regulates Apoptosis of Bovine Ovarian Granulosa Cells by Progestogen Receptor Signaling Pathway

The purpose of the present investigation was to assess the function of LRH-1 on GCs and the mechanisms involved. Here, LRH- was highly expressed in the bovine GCs of atretic follicles. Treatment with 50 μM of LRH-1 agonist (DLPC) significantly induced the expression of LRH-1 (p < 0.05). In particular, LRH-1 activation blocked the progestogen receptor signaling pathway via downregulating progesterone production and progestogen receptor levels (p < 0.05), but had no effect on 17 beta-estradiol synthesis. Meanwhile, LRH-1 activation promoted the apoptosis of GCs and increased the activity of caspase 3 (p < 0.05). Importantly, upregulating the progestogen receptor signaling pathway with progestogen could attenuate the LRH-1-induced proapoptotic effect. Moreover, treatment with progestogen decreased the activity of the proapoptotic gene caspase 3 and increased the expression of antiapoptotic gene Bcl2 in LRH-1 activated GCs (p < 0.05). Taken together, these results demonstrate that LRH-1 might be dependent on the progestogen receptor signaling pathway to modulate bovine follicular atresia.

AKR1C1/2 inhibition by MPA sensitizes platinum resistant ovarian cancer towards carboplatin

In recurrent epithelial ovarian cancer (EOC) most patients develop platinum-resistance. On molecular level the NRF2 pathway, a cellular defense mechanism against reactive oxygen species, is induced. In this study, we investigate AKR1C1/2, target of NRF2, in a well-established EOC collective by immunohistochemistry and in a panel of ovarian cancer cell lines including platinum-resistant clones. The therapeutic effect of carboplatin and MPA as monotherapy or in combination was assessed by functional assays, using OV90 and OV90cp cells. Molecular mechanisms of action of MPA were investigated by NRF2 silencing and AKR activity measurements. Immunohistochemical analysis revealed that AKR1C1/2 is a key player in the development of chemoresistance and an independent indicator for short PFS (23.5 vs. 49.6 months, p = 0.013). Inhibition of AKR1C1/2 by MPA led to a concentration- and time-dependent decline of OV90 viability and to an increased response to CP in vitro. By NRF2 silencing, however, the effects of MPA treatment were reduced. Concludingly, our data suggest that a combination therapy of carboplatin and MPA might be a promising therapeutic approach to increase response rates of EOC patients, which should be explored in clinical context.

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

OBJECTIVE

To describe tubal histopathological abnormalities in women with germline BRCA1/2 mutations and in controls.

METHODS

Consecutive women with BRCA1/2 mutations undergoing bilateral salpingo-oophorectomy between 2010 and 2020 in two centers (San Gerardo Hospital, Monza and San Matteo Hospital, Pavia) were considered in this analysis and compared with controls who had the same surgical procedure for benign conditions. Frequency of p53 signature, serous tubal intraepithelial carcinoma, and high-grade serous ovarian cancer were compared between the two groups.

RESULTS

A total of 194 women with pathogenic BRCA1/2 mutations underwent prophylactic salpingo-oophorectomy. Of these, 138 women (71%) had a completely negative histological examination, while in 56 (29%) patients an ovarian or tubal alteration was reported. Among controls, 84% of patients had a p53wt signature, while 16% had a p53 signature. There was no difference in the frequency of a p53 signature between cases and controls; however, women with BRCA1/2 mutations were more likely to have pre-malignant or invasive alterations of tubal or ovarian epithelium (p=0.015). Among mutation carriers, older age both at genetic testing and at surgery was associated with an increased risk of having malignancies (OR=1.07, p=0.006 and OR=1.08, p=0.004, respectively). The risk of malignancy seems to be increased in patients with a familial history of high-grade serous ovarian cancer. Previous therapy with tamoxifen was significantly more frequent in patients with malignant lesions (40.0% vs 21.3%, p=0.006).

CONCLUSION

We found that a p53 signature is a frequent finding both in BRCA1/2 mutation carriers and in controls, while pre-invasive and invasive lesions are more frequent in BRCA1/2 mutation carriers. Genetic and clinical characteristics are likely to affect the progression to malignancy.

Models for measuring metabolic chemical changes in the metastasis of high grade serous ovarian cancer: fallopian tube, ovary, and omentum

Ovarian cancer (OC) is the most lethal gynecologic malignancy and high grade serous ovarian cancer (HGSOC) is the most common and deadly subtype, accounting for 70-80% of OC deaths. HGSOC has a distinct pattern of metastasis as many believe it originates in the fallopian tube and then it metastasizes first to the ovary, and later to the adipose-rich omentum. Metabolomics has been heavily utilized to investigate metabolite changes in HGSOC tumors and metastasis. Generally, metabolomics studies have traditionally been applied to biospecimens from patients or animal models; a number of recent studies have combined metabolomics with innovative cell-culture techniques to model the HGSOC metastatic microenvironment for the investigation of cell-to-cell communication. The purpose of this review is to serve as a tool for researchers aiming to model the metastasis of HGSOC for metabolomics analyses. It will provide a comprehensive overview of current knowledge on the origin and pattern of metastasis of HGSOC and discuss the advantages and limitations of different model systems to help investigators choose the best model for their research goals, with a special emphasis on compatibility with different metabolomics modalities. It will also examine what is presently known about the role of small molecules in the origin and metastasis of HGSOC.

Progestin Significantly Inhibits Carcinogenesis in the Mogp-TAg Transgenic Mouse Model of Fallopian Tube Cancer

Recent studies suggest that the fallopian tube epithelium (FTE) harbors the precursor for high grade ovarian cancer, 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 is not well characterized. The murine oviduct-specific glycoprotein promotor-driven simian virus 40 large T-Antigen (mogp-TAg) transgenic mouse model develops neoplastic lesions in the fallopian tube (FT) in a manner similar to that described in human fallopian and ovarian cancer. In this study, we investigated the inhibitory effects of the progestin Depo-medroxyprogesterone acetate (DMPA) on FT carcinogenesis following treatment for 3 and 7 weeks in 5-week-old mogp-TAg mice. Overall, compared to vehicle-treated mice, the FT of DMPA-treated mice was significantly smaller (p<0.0005), accumulated fewer p53-positive cells, had normal distribution of ciliated cells, less nuclear pleomorphism and epithelial tufting, and had a significantly lower proliferative index (p=0.001). Accumulation of p53 signatures and serous tubal intraepithelial carcinomas (STICs) in the FT was significantly reduced in the DMPA (p<0.0005) treatment group. Moreover, the FT of the DMPA-treated mice developed significantly less adenocarcinoma compared to vehicle (p<0.005) at both treatment time points. DMPA treatment significantly induced cleaved caspase-3 (p<0.0005) in the FTE compared to vehicle suggesting that apoptosis is involved in DMPA-related clearance of abnormal cells from the FT. These data demonstrate that DMPA targets early events in FT carcinogenesis by clearing genetically damaged cells, leading to marked reduction in adenocarcinoma, supporting progestins as chemopreventives for FT and ovarian cancer.

Hormone therapy for ovarian cancer: Emphasis on mechanisms and applications (Review)

Ovarian cancer (OC) remains the leading cause of mortality due to gynecological malignancies. Epidemiological studies have demonstrated that steroid hormones released from the hypothalamic-pituitary-ovarian axis can play a role in stimulating or inhibiting OC progression, with gonadotropins, estrogens and androgens promoting OC progression, while gonadotropin-releasing hormone (GnRH) and progesterone may be protective factors in OC. Experimental studies have indicated that hormone receptors are expressed in OC cells and mediate the growth stimulatory or growth inhibitory effects of hormones on these cells. Hormone therapy agents have been evaluated in a number of clinical trials. The majority of these trials were conducted in patients with relapsed or refractory OC with average efficacy and limited side-effects. A better understanding of the mechanisms through which hormones affect cell growth may improve the efficacy of hormone therapy. In the present review article, the role of hormones (GnRH, gonadotropins, androgens, estrogens and progestins) and their receptors in OC tumorigenesis, and hormonal therapy in OC treatment is discussed and summarized.

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

CONTEXT

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.

OBJECTIVE

This study defines PR-driven oncogenic signaling mechanisms in p53-mutant human fallopian tube epithelia (hFTE), a precursor of the most aggressive OC subtype.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

NF-κB-miR-155 axis activation mediates ovulation-induced oncogenic effects in fallopian tube epithelium

The fallopian tube secretory epithelial cells (FTSECs) are the cell-of-origin of most high-grade serous ovarian carcinomas (HGSOC). FTSECs are repeatedly exposed to inflammation induced by follicular fluid (FF) that is released with every ovulation cycle throughout a woman's reproductive years. Uninterrupted ovulation cycles are an established risk factor for HGSOC. Stimuli present in the FF induce an inflammatory environment which may cause DNA damage eventually leading to serous tumorigenesis. With the aim of elucidating possible mechanistic pathways, we established an 'ex vivo persistent ovulation model' mimicking the repeated exposure of human benign fallopian tube epithelium (FTE) to FF. We performed mass spectrometry analysis of the secretome of the ex vivo cultures as well as confirmatory targeted expressional and functional analyses. We demonstrated activation of the NF-κB pathway and upregulation of miR-155 following short-term exposure of FTE to human FF. Increased expression of miR-155 was also detected in primary HGSOC tumors compared with benign primary human FTE and corresponded with changes in the expression of miR-155 target genes. The phenotype of miR-155 overexpression in FTSEC cell line is of increased migratory and altered adhesion capacities. Overall, activation of the NF-κB-miR-155 axis in FTE may represent a possible link between ovulation-induced inflammation, DNA damage, and transcriptional changes that may eventually lead to serious carcinogenesis.

Reduced SKP1 and CUL1 expression underlies increases in Cyclin E1 and chromosome instability in cellular precursors of high-grade serous ovarian cancer

BACKGROUND

High-grade serous ovarian cancer (HGSOC) is the most common and lethal ovarian cancer histotype. Chromosome instability (CIN, an increased rate of chromosome gains and losses) is believed to play a fundamental role in the development and evolution of HGSOC. Importantly, overexpression of Cyclin E1 protein induces CIN, and genomic amplification of CCNE1 contributes to HGSOC pathogenesis in ~20% of patients. Cyclin E1 levels are normally regulated in a cell cycle-dependent manner by the SCF (SKP1-CUL1-FBOX) complex, an E3 ubiquitin ligase that includes the proteins SKP1 and CUL1. Conceptually, diminished SKP1 or CUL1 expression is predicted to underlie increases in Cyclin E1 levels and induce CIN.

METHODS

This study employs fallopian tube secretory epithelial cell models to evaluate the impact diminished SKP1 or CUL1 expression has on Cyclin E1 and CIN in both short-term (siRNA) and long-term (CRISPR/Cas9) studies.

RESULTS

Single-cell quantitative imaging microscopy approaches revealed changes in CIN-associated phenotypes and chromosome numbers and increased Cyclin E1 in response to diminished SKP1 or CUL1 expression.

CONCLUSIONS

These data identify SKP1 and CUL1 as novel CIN genes in HGSOC precursor cells that may drive early aetiological events contributing to HGSOC development.

Depot-Medroxyprogesterone Acetate Use Is Associated with Decreased Risk of Ovarian Cancer: The Mounting Evidence of a Protective Role of Progestins

BACKGROUND

Combined oral contraceptive use is associated with a decreased risk of invasive epithelial ovarian cancer (ovarian cancer). There is suggestive evidence of an inverse association between progestin-only contraceptive use and ovarian cancer risk, but previous studies have been underpowered.

METHODS

The current study used primary data from 7,977 women with ovarian cancer and 11,820 control women in seven case-control studies from the Ovarian Cancer Association Consortium to evaluate the association between use of depot-medroxyprogesterone acetate (DMPA), an injectable progestin-only contraceptive, and ovarian cancer risk. Logistic models were fit to determine the association between ever use of DMPA and ovarian cancer risk overall and by histotype. A systematic review of the association between DMPA use and ovarian cancer risk was conducted.

RESULTS

Ever use of DMPA was associated with a 35% decreased risk of ovarian cancer overall (OR, 0.65; 95% confidence interval, 0.50-0.85). There was a statistically significant trend of decreasing risk with increasing duration of use (P trend < 0.001). The systematic review yielded six studies, four of which showed an inverse association and two showed increased risk.

CONCLUSIONS

DMPA use appears to be associated with a decreased risk of ovarian cancer in a duration-dependent manner based on the preponderance of evidence. Further study of the mechanism through which DMPA use is associated with ovarian cancer is warranted.

IMPACT

The results of this study are of particular interest given the rise in popularity of progestin-releasing intrauterine devices that have a substantially lower progestin dose than that in DMPA, but may have a stronger local effect.

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.

Progesterone Modulates Mitochondrial Functions in Human Glioblastoma Cells

A substantial literature supports the notion that cancer is a metabolic disease. Mitochondria are sexually dimorphic, and progesterone (P4) plays a key regulatory role in mitochondrial functions. We investigated the effect of P4 on mitochondrial functions in three human glioblastoma multiforme (GBM) cell lines. In dose-response and time-response studies, GBM cells were exposed to different concentrations of P4 followed by mitochondrial stress-testing with a Seahorse analyzer. Data were analyzed for oxygen consumption rate (OCR), extracellular acidification rate (ECAR), and spare respiratory capacity (SRC) to determine the effects of P4 exposure on mitochondrial respiration and rate of glycolysis. We also examined the effect of P4 on mitochondrial superoxide radical generation by confocal microscopy. As early as 1h post-P4 exposure, we found a substantial dose-dependent inhibitory effect of P4 on OCR, ECAR, and SRC in all GBM cell lines. P4 treatment altered the levels of basal respiration, maximum respiration, nonmitochondrial oxygen consumption, ATP production, and proton leak. P4 given at 80-μM concentration showed the maximum inhibitory effect compared to controls. Live imaging data showed an 11-22% increase in superoxide radical generation in all three GBM cell lines following 6h exposure to a high concentration of P4. Our data show that high-dose P4 exerts an inhibitory effect on both mitochondrial respiration and glycolysis in GBM cells. These effects would lead to decreased tumor size and rate of growth, representing a potential treatment to control the spread of GBM.

Progesterone suppresses the progression of colonic carcinoma by increasing the activity of the GADD45α/JNK/c‑Jun signalling pathway

Colorectal cancer (CRC) is the third most diagnosed cancer worldwide. Progesterone is associated with a decreased risk of CRC and leads to a favourable prognosis. However, the specific mechanism by which progesterone suppresses malignant progression remains to be elucidated. In the present study, the level of progesterone was first analysed in 77 patients with CRC, and immunohistochemistry was performed to detect the expression of progesterone receptor (PGR) in the paired specimens. The correlations between progesterone, PGR and CRC prognosis were assessed. A Cell Counting Kit-8 assay was then used to detect proliferation of the CRC cells. Flow cytometry was performed to estimate apoptosis and to evaluate the cycle of the CRC cells. A xenograft tumour model was established in nude mice to assess the role of progesterone in tumour growth. Finally, a PCR microarray was used to screen differentially expressed genes to further interpret the mechanism by which progesterone inhibits the malignant progression of CRC. It was found that low expression of progesterone and PGR were significantly associated with poor prognosis of CRC. In addition, progesterone suppressed CRC cell proliferation by arresting the cell cycle and inducing apoptosis in vitro. Moreover, the inhibitory role of progesterone in tumour growth was verified in vivo. Further investigation showed that the level of growth arrest and DNA damage-inducible protein α (GADD45α) was up-regulated by progesterone, and this was followed by the activation of the JNK pathway. Progesterone increased the activity of the JNK pathway via GADD45α to inhibit proliferation by arresting the cell cycle and inducing apoptosis, thereby suppressing the malignant progression of CRC. Therefore, it can be concluded that progesterone and PGR might act as inhibiting factors for poor prognosis of CRC.

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.

Low-level expression of necroptosis factors indicates a poor prognosis of the squamous cell carcinoma subtype of non-small-cell lung cancer

Background

The programmed cell death pathway necroptosis may synergize with the DNA damage response (DDR) in opposing tumor progression. While our basic mechanistic understanding of the necroptotic cell death advances rapidly, its prognostic implications have not been thoroughly examined in cancers.

Methods

We included 394 patients with stage I non-small-cell lung cancer (NSCLC) who underwent surgical tumor resection between 1 January 1997 and 31 December 2011 and measured expression levels of nine proteins involved in necroptosis and the DDR in primary samples from 394 patients using tissue microarray. Protein expression evaluated by using an H-score method was dichotomized by the median value. The overall survival as the endpoint was calculated from the time of diagnosis to the time of the last follow-up or death.

Results

We find that low-level expression of the necroptosis markers RIPK3 and PELI1 is associated with high risk of patient death. High-level expression of the key DDR factor p53 in combination with low-level expression of either RIPK3 or PELI1 increases the risk further. These gene expression effects appear to occur specifically in the squamous cell carcinoma (SCC) subtype of stage I NSCLC, while not observed in the non-SCC subtypes.

Conclusions

Low-level expression of such necroptosis factors as RIPK3 and PELI1 in combination with high-level expression of the DDR factor p53 can serve as a critical indicator in predicting survival of stage I NSCLC patients with the SCC subtype.

Sphingolipids as multifaceted mediators in ovarian cancer

Ovarian cancer is the most lethal gynaecological malignancy. It is commonly diagnosed at advanced stage when it has metastasised to the abdominal cavity and treatment becomes very challenging. While current standard therapy involving debulking surgery and platinum + taxane-based chemotherapy is associated with high response rates initially, the large majority of patients relapse and ultimately succumb to chemotherapy-resistant disease. In order to improve survival novel strategies for early detection and therapeutics against treatment-refractory disease are urgently needed. A promising new target against ovarian cancer is the sphingolipid pathway which is commonly hijacked in cancer to support cell proliferation and survival and has been shown to promote chemoresistance and metastasis in a wide range of malignant neoplasms. In particular, the sphingosine kinase 1-sphingosine 1-phosphate receptor 1 axis has been shown to be altered in ovarian cancer in multiple ways and therefore represents an attractive therapeutic target. Here we review the roles of sphingolipids in ovarian cancer progression, metastasis and chemoresistance, highlighting novel strategies to target this pathway that represent potential avenues to improve patient survival.

The organoid: A research model for ovarian cancer

Epithelial ovarian cancer (EOC) is a heterogeneous disease with a variety of distinct clinical and molecular characteristics. The currently available and common research models for EOC include tumor cell lines and patient-derived xenografts. However, these models have certain shortcomings: establishing a cell line is time-consuming, loss of genetic traits after long-term culture is a possibility, and investment is required in terms of animal care facilities. Therefore, better research models are required. Organoid technology was originally developed from colorectal cancer. Tumor organoid is a three-dimensional culture system and can help accurately recapture the tumor phenotype from the original tumor. Tumor organoid systems can overcome the above-mentioned shortcomings of the currently available research models. The organoid model can be used for culturing ovarian cancer subtypes, screening drugs, assessing genomes, and establishing biobanks. However, the currently available organoid models can only culture one type of cells, epithelial cells. Therefore, an organoid-on-a-chip device can be developed in the future to provide a microenvironment for cell–cell, cell–matrix, and cell–media interactions. Thus, organoid models can be used in ovarian cancer research and can generate a simulated in vivo system, enabling studies on the heterogeneity of ovarian cancer.

Targeting progesterone signaling prevents metastatic ovarian cancer

Effective cancer prevention requires the discovery and intervention of a factor critical to cancer development. Here we show that ovarian progesterone is a crucial endogenous factor inducing the development of primary tumors progressing to metastatic ovarian cancer in a mouse model of high-grade serous carcinoma (HGSC), the most common and deadliest ovarian cancer type. Blocking progesterone signaling by the pharmacologic inhibitor mifepristone or by genetic deletion of the progesterone receptor (PR) effectively suppressed HGSC development and its peritoneal metastases. Strikingly, mifepristone treatment profoundly improved mouse survival (∼18 human years). Hence, targeting progesterone/PR signaling could offer an effective chemopreventive strategy, particularly in high-risk populations of women carrying a deleterious mutation in the BRCA gene.

A clear cancer cell line (150057) derived from human endometrial carcinoma harbors two novel mutations

BACKGROUND

Cell lines are extremely useful for both basic and clinical research. Thus, establishing endometrial cancer cell lines with malignant histology is important. This study aimed to extensively characterize an endometrial clear cell carcinoma cell line.

METHODS

This cell line, named 150,057, was derived from the endometrial clear cell cancer of a 63-year-old woman. The morphology, chromosomes, chemosensitivity, tumor markers, xenotransplantation characteristics, and cancer-related genes of the cell line were characterized.

RESULTS

This cell line exhibited adequate growth, being passaged more than 70 times. The morphology of the cells was polygonal with a cobblestone-like appearance. Karyotyping of the cell line revealed a hypodiploid chromosomal number. 150057 cells expressed CA19-9 and CA125. The cell line was sensitive to doxorubicin, paclitaxel, carboplatin, and cisplatin. After the cells were transplanted into the subcutaneous region of non-obese diabetic-severe combined immunodeficiency mice, they generated xenograft tumors with similar histology as the original tumor. A total of 59 somatic nucleotide mutations were identified in 25 of the 53 examined tumor suppressor genes and oncogenes. Two novel mutations were found in FGFR3 and ARID1A.

CONCLUSION

We established and characterized an endometrial clear cell carcinoma cell line that may be useful in carcinogenesis and treatment research for endometrial cancer.

The Origin of Ovarian Cancer Species and Precancerous Landscape

Unlike other human cancers, in which all primary tumors arise de novo, ovarian epithelial cancers are primarily imported from either endometrial or fallopian tube epithelium. The prevailing paradigm in the genesis of high-grade serous carcinoma (HGSC), the most common ovarian cancer, posits to its development in fallopian tubes through stepwise tumor progression. Recent progress has been made not only in gathering terabytes of omics data but also in detailing the histologic-molecular correlations required for looking into, and making sense of, the tissue origin of HGSC. This emerging paradigm is changing many facets of ovarian cancer research and routine gynecology practice. The precancerous landscape in fallopian tubes contains multiple concurrent precursor lesions, including serous tubal intraepithelial carcinoma (STIC), with genetic heterogeneity providing a platform for HGSC evolution. Mathematical models imply that a prolonged time (decades) elapses from the development of a TP53 mutation, the earliest known molecular alteration, to an STIC, followed by a shorter span (6 years) for progression to an HGSC. Genetic predisposition accelerates the trajectory. This timeline may allow for the early diagnosis of HGSC and STIC, followed by intent-to-cure surgery. This review discusses the recent advances in this tubal paradigm and its biological and clinical implications, alongside the promise and challenge of studying STIC and other precancerous lesions of HGSC.

Significance of Single-Nucleotide Variants in Long Intergenic Non-protein Coding RNAs

Single-nucleotide variants (SNVs) are the most common genetic variants and universally present in the human genome. Genome-wide association studies (GWASs) have identified a great number of disease or trait-associated variants, many of which are located in non-coding regions. Long intergenic non-protein coding RNAs (lincRNAs) are the major subtype of long non-coding RNAs; lincRNAs play crucial roles in various disorders and cellular models via multiple mechanisms. With rapid growth in the number of the identified lincRNAs and genetic variants, there is great demand for an investigation of SNVs in lincRNAs. Hence, in this article, we mainly summarize the significant role of SNVs within human lincRNA regions. Some pivotal variants may serve as risk factors for the development of various disorders, especially cancer. They may also act as important regulatory signatures involved in the modulation of lincRNAs in a tissue- or disorder-specific manner. An increasing number of researches indicate that lincRNA variants would potentially provide additional options for genetic testing and disease risk assessment in the personalized medicine era.

Screening and Prevention for High-Grade Serous Carcinoma of the Ovary Based on Carcinogenesis-Fallopian Tube- and Ovarian-Derived Tumors and Incessant Retrograde Bleeding

High-grade serous carcinoma (HGSC) is the most common and lethal subtype of ovarian carcinoma. Many HGSCs are now believed to originate in the fallopian tube epithelium; ovarian surface epithelium is another possible origin. Thus, current screening methods, i.e., ultrasonography and serum CA-125 measurements, have a limitation in their early detection. Recently, circulating biomarkers, such as tumor DNA, autoantibody, and microRNA, have been investigated to detect HGSCs. As cancer cells in the fallopian tube flow into the endometrial cavity, the detection of exfoliated cells, tumor DNA, and proteome from samples obtained from the endometrial cavity or the cervix may be useful. The risk of ovarian serous carcinoma is affected by the use of oral contraceptive and menopausal hormone therapy (MHT). MHT regimens causing endometrial bleeding increase serous carcinoma risk, hence, incessant retrograde bleeding from the endometrial cavity into the Douglas pouch appears to play an important role in high-grade serous carcinogenesis. In this review, we provide an overview of current and novel screening methods and prevention approaches for ovarian and fallopian tube HGSC.

Fallopian tube initiation of high grade serous ovarian cancer and ovarian metastasis: Mechanisms and therapeutic implications

Ovarian cancer is the most lethal gynecologic malignancy and the fifth leading cause of cancer-related death in women. Although outcomes have improved in recent years, there remains an unmet clinical need to understand the early pathogenesis of ovarian cancer in order to identify new diagnostic approaches and agents of chemoprevention and chemotherapy. While high grade serous ovarian cancer (HGSOC), the most abundant histotype, was initially thought to arise from the ovarian surface epithelium, there is an increasing body of evidence suggesting that HGSOC originates in the fallopian tube. With this new understanding of cell of origin, understanding of disease development requires analysis with a novel perspective. Currently, factors that drive the initiation and migration of dysplastic tubal epithelial cells from the fallopian tube to the ovary are not yet fully defined. These factors include common mutations to fallopian tube epithelial cells, as well as factors originating from both the fallopian tube and ovary which are capable of inducing transformation and dissemination in said cells. Here, we review these changes, their causative agents, and various potential means of intervention.

Human fallopian tube epithelial cells exhibit stemness features, self-renewal capacity, and Wnt-related organoid formation

BACKGROUND

Fallopian tube epithelial cells (FTEC) were thought to be the origin of high-grade serous ovarian carcinoma (HGSOC). Knowledge of the stemness or initiating characteristics of FTEC is insufficient. Previously, we have characterized the stemness cell marker of FTEC, this study aims to further characterize the clonogenicity and spheroid features of FTEC.

METHODS

We successfully derived FTECs from the epithelial layer of the human fallopian tubes. We examined the morphology, proliferation rate, doubling time, and clonal growth of them. At passage 3, the sphere formations on gelatin-coated culture, suspension culture, and matrigel culture were observed, and the expression of LGR5, SSEA3, SSEA4, and other stemness markers was examined. Furthermore, tissue-reconstituted organoids from coculture of FTEC, fallopian stromal cells (FTMSC) and endothelial cells (HUVEC) were examined.

RESULTS

FTEC exhibited cuboidal cell morphology and maintained at a constant proliferation rate for up to nine passages (P9). FTEC could proliferate from a single cell with a clonogenic efficiency of 4%. Flow cytometry revealed expressions of normal stem cell markers (SSEA3, SSEA4, and LGR5) and cancer stem cell markers (CD24, CD44, CD117, ROR1, and CD133). FTEC formed spheres and colonies when cultured on low attach dish. In the presence of Matrigel, the stemness and colony formation activity were much enhanced. In co-culturing with FTMSC and HUVEC, FTEC could form organoids that could be blocked by Wnt inhibitor DKK1. Expressions of LGR5 and FOXJ1 expression were also decreased by adding DKK1.

CONCLUSION

We demonstrated abundantly presence of stem cells in human FTECs which are efficient in forming colonies, spheres and organoids, relying on Wnt signaling. We also reported for the first time the generation of organoid from reconstitutied cell lineages in the tissue. This may provide a new model for studying the regneration and malignant transformation of the tubal epithelium.

A dog oviduct-on-a-chip model of serous tubal intraepithelial carcinoma

Ovarian cancer is the fifth cause of cancer-related mortality in women, with an expected 5-year survival rate of only 47%. High-grade serous carcinoma (HGSC), an epithelial cancer phenotype, is the most common malignant ovarian cancer. It is known that the precursors of HGSC originate from secretory epithelial cells within the Fallopian tube, which first develops as serous tubal intraepithelial carcinoma (STIC). Here, we used gene editing by CRISPR-Cas9 to knock out the oncogene p53 in dog oviductal epithelia cultured in a dynamic microfluidic chip to create an in vitro model that recapitulated human STIC. Similar to human STIC, the gene-edited oviduct-on-a-chip, exhibited loss of cell polarization and had reduced ciliation, increased cell atypia and proliferation, with multilayered epithelium, increased Ki67, PAX8 and Myc and decreased PTEN and RB1 mRNA expression. This study provides a biomimetic in vitro model to study STIC progression and to identify potential biomarkers for early detection of HGSC.