Transcriptome-wide association analyses identify an association between ARL14EP and polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is a common endocrine disorder, which is accompanied by a variety of comorbidities including metabolic, reproductive, and psychiatric disorders. Genome-wide association studies have identified several genetic variants that are associated with PCOS. However, these variants often occur outside of coding regions and require further investigation to understand their contribution to PCOS. A transcriptome-wide association study (TWAS) was performed to uncover heritable gene expression profiles that are associated with PCOS in two independent cohorts. Causal gene prioritization was subsequently performed and expression of genes prioritized through these analyses was examined in 49 PCOS patients and 30 controls. TWAS analyses revealed that increased expression of ARL14EP was significantly associated with PCOS risk in the discovery (P = 1.6 × 10-6) and replication cohorts (P = 2.0 × 10-13). Gene prioritization pipelines provided further evidence that ARL14EP is the most likely causal gene at this locus. ARL14EP gene expression was shown to be significantly different between PCOS cases and controls, after adjusting for body mass index, age and testosterone levels (P = 1.2 × 10-13). This study has provided evidence for the role of ARL14EP in PCOS. Given that ARL14EP has been reported to play an important role in chromatin remodeling, variants affecting the expression of ARL14EP may also affect the expression of other genes that contribute to PCOS pathogenesis.

A comparison of synoptic reports and dictated reports to enhance and standardize surgical documentation and quality of care in epithelial ovarian cancer.

OBJECTIVE: The purpose of this study is to assess the degree to which synoptic reports (SRs) and dictated reports (DRs) document elements of the Ovarian Cancer Pan-Canadian Standards Data Elements (OCPCDE) checklist, and to compare their completeness. Analysis of dictated versus synoptic reporting has never been performed for suspected epithelial ovarian cancer (EOC) based on literature review at the time of data collection (1-12). METHODS: A retrospective chart review was performed including 254 charts of women 18 years or older, from 2012 to 2017, undergoing surgery for suspected EOC. Charts from five gynecologic oncologists, at a single tertiary care centre were used. The OCPCDE checklist was used to evaluate their completeness. Comparison of completeness between SRs and DRs was done using linear regression with a fixed effect of surgeon to account for intraclass correlation. RESULTS: The data showed that SRs included 20.1% more data elements than DRs. Data elements that may be perceived as being more critical were more likely to be documented in SRs. Residual disease data was documented in 51.7% DR versus 99.1% of SR. Descriptive data upon entering the abdomen was more frequently documented in DRs. CONCLUSION: This study shows that synoptic reporting includes more data elements deemed important by the OCPCDE checklist authors for suspected epithelial ovarian cancer surgery in our centre. We would recommend continuation of SRs in our department, and implementation of synoptic reporting in other gynecologic oncology centres where surgery for suspected epithelial ovarian cancer is performed.

Exploring the role of a multidisciplinary hereditary gynecologic oncology clinic in epithelial ovarian cancer risk-reducing surgical decision-making practices: A mixed-methods study.

Individuals that have gynecologic reproductive organs with pathogenic variants in BRCA1 or BRCA2 ("BRCA-positive") have an increased risk of developing high-grade serous ovarian cancer (HGSOC). The majority of HGSOC develops in the fallopian tubes and later spreads to the ovaries and peritoneal cavity. Therefore, risk-reducing salpingo-oophorectomy (RRSO) is recommended for those who are BRCA-positive to preventatively remove their ovaries and fallopian tubes. The Hereditary Gynecology Clinic (HGC) is a provincial program in Winnipeg, Canada, that specifically targets care to the unique needs of such individuals through an interdisciplinary team of gynecological oncologists, menopause specialists, and registered nurses. A mixed-methods study design was used to explore the decision-making processes of these BRCA-positive individuals who have been recommended (or who completed) RRSO and experiences with healthcare providers at the HGC influenced this decision. Individuals who are BRCA-positive without a previous diagnosis of HGSOC and who had previously received genetic counselling were recruited from the HGC and the provincial cancer genetics program (Shared Health Program of Genetics & Metabolism). Forty-three people completed a survey and 15 participated in an in-depth interview about their experiences and decisions surrounding RRSO. Surveys were analyzed to compare scores on validated scales related to decision-making and cancer-related worry. Qualitative interviews were transcribed, coded, and analyzed using interpretive description. Participants described the complex decisions faced by those who are BRCA-positive, which are intertwined with life experiences and circumstances including age, marital status, and family disease history. Participants interpreted their HGSOC risk through a personalized "lens" of contextual factors that impacted perceptions about the practical and emotional implications of RRSO and the need for surgery. Mean scores on validated scales evaluating the HGC's impact on decisional outcomes and preparedness for decision-making about RRSO were not significant, indicating that the HGC played a supportive role, rather than helping with decision-making itself. Therefore, we present a novel framework that consolidates the various influences on decision-making and connects them to the psychological and practical implications of RRSO in the context of the HGC. Strategies for improving support, decisional outcomes, and the overall experiences of individuals who are BRCA-positive attending the HGC are also described.

Perioperative Incidence of Venous Thromboembolism in Patients With Ovarian Cancer Using Four Different Data Collection Methods: A Manitoba Ovarian Cancer Outcomes (MOCO) Group Study.

OBJECTIVE: To evaluate the incidence of venous thromboembolism (VTE) in 90-day pre-operative period and at 30 and 90 days post surgery in patients who underwent debulking for ovarian cancer, analyze the impact of extended prophylaxis that was initiated in 2012, and examine the influence of data collection technique on reported rates of VTE. METHODS: This retrospective database and records study examined rates of VTE in epithelial ovarian cancer patients in Manitoba, Canada between 2004 and 2016. Cases of VTE were identified using ICD codes, drug prescriptions, and records reviews; 4 different data collection methods were used. Analysis was performed with analysis of variance, Kruskal-Wallis and χ2 tests, and interrupted time series models. RESULTS: Data collection identified 823 debulking surgeries, with a final cohort of 779 patients; data were analyzed before and after extended prophylaxis intervention. Overall rates of VTE varied by collection method and were 1.82%-5.47%, 0.36%-3.16%, 0.85%-1.46%, and 1.46%-2.79%, respectively. During this timeframe, we noted a significant increase in the use of neoadjuvant chemotherapy (P = 0.010) and stage migration to stage 3 (P < 0.001). CONCLUSION: We report the rates of VTE utilizing 4 different data collection methods. We found a low overall rate, with some trends requiring further investigation. This study highlights the importance of data collection method on the reported rates of VTE in research.

Chromosome instability is prevalent and dynamic in high-grade serous ovarian cancer patient samples.

OBJECTIVE: High-grade serous ovarian cancer (HGSOC) is the most lethal gynaecological malignancy in women with a high level of mortality, metastatic disease, disease recurrence and multi-drug resistance. Many previous studies have focused on characterising genome instability in recurrent resistant HGSOC and while this has advanced our understanding of HGSOC, our fundamental knowledge of the mechanisms driving genome instability remains limited. Chromosome instability (CIN; an increased rate of chromosome gains and losses) is a form of genome instability that is commonly associated with recurrence and multi-drug resistance in many cancer types but has just begun to be characterised in HGSOC. METHOD: To examine the relationship between CIN and HGSOC, we employed single-cell quantitative imaging microscopy approaches capable of capturing the cell-to-cell heterogeneity associated with CIN, to assess the prevalence and dynamics of CIN within individual and patient-matched HGSOC ascites and solid tumour samples. RESULTS: CIN occurs in 90.9% of ascites samples and 100% of solid tumours, while in-depth analyses identified statistically significant temporal dynamics within the serial ascites samples. In general, aneuploidy and CIN increase with disease progression and frequently decrease following chemotherapy treatments in responsive disease. Finally, our work identified higher levels of CIN in solid tumours relative to ascites samples isolated from the same individual, which identifies a novel difference existing between solid tumours and ascites samples. CONCLUSIONS: Our findings provide novel insight into the relationship between CIN and HGSOC, and uncover a previously unknown relationship existing between CIN in solid tumours and metastatic disease (ascites).

Response to Multi-Line Chemotherapy in Non-Serous Epithelial Ovarian Cancer.

OBJECTIVES: To describe the response rate to chemotherapy, rates of recurrence, and overall survival in patients with non-serous epithelial ovarian cancers. METHODS: This retrospective cohort study used the Manitoba Cancer Registry to identify all women with non-serous epithelial ovarian, fallopian, or peritoneal cancer treated between 1995 and 2010. Chart review entailed extracting information regarding therapy and outcomes. All patients with recurrence were identified and response to chemotherapy was assessed. RESULTS: We identified 392 patients with non-serous ovarian cancers, 192 of whom received chemotherapy in the first-line setting. Optimal debulking resulted in improvements in rates of recurrence and overall survival (P < 0.001). Histology did not have an effect on recurrence or overall survival. Forty-eight patients (25%) had a recurrence and received second-line therapy, and 21 (11%) received third-line therapy. Response rates were similar regardless of histology. In the second-line setting, 40.9%-83.3% of patients (other > mucinous > clear cell > endometrioid) and in the third-line setting, 33.3%-75.0% of patients (other > mucinous > clear cell > endometrioid) received >6 lines of chemotherapy. Twenty-three percent of patients experienced a recurrence within 2 years of first-line therapy. Two-year survival was 79.4% after first-line treatment, 27.6% after second-line treatment, and 19.5% after third-line treatment. CONCLUSION: Patients with clear cell ovarian cancer had chemotherapy continuation rates similar to those of previously reported studies. This is one of the first studies reporting response rates for mucinous and endometrioid subtypes. Recurrent disease responds to treatment with second- and third-line therapy, emphasizing the importance of offering patients subsequent lines of chemotherapy for disease management. Further studies are needed to determine the optimal regimen.

The temporal dynamics of chromosome instability in ovarian cancer cell lines and primary patient samples.

Epithelial ovarian cancer (EOC) is the most prevalent form of ovarian cancer and has the highest mortality rate. Novel insight into EOC is required to minimize the morbidity and mortality rates caused by recurrent, drug resistant disease. Although numerous studies have evaluated genome instability in EOC, none have addressed the putative role chromosome instability (CIN) has in disease progression and drug resistance. CIN is defined as an increase in the rate at which whole chromosomes or large parts thereof are gained or lost, and can only be evaluated using approaches capable of characterizing genetic or chromosomal heterogeneity within populations of cells. Although CIN is associated with numerous cancer types, its prevalence and dynamics in EOC is unknown. In this study, we assessed CIN within serial samples collected from the ascites of five EOC patients, and in two well-established ovarian cancer cell models of drug resistance (PEO1/4 and A2780s/cp). We quantified and compared CIN (as measured by nuclear areas and CIN Score (CS) values) within and between serial samples to glean insight into the association and dynamics of CIN within EOC, with a particular focus on resistant and recurrent disease. Using quantitative, single cell analyses we determined that CIN is associated with every sample evaluated and further show that many EOC samples exhibit a large degree of nuclear size and CS value heterogeneity. We also show that CIN is dynamic and generally increases within resistant disease. Finally, we show that both drug resistance models (PEO1/4 and A2780s/cp) exhibit heterogeneity, albeit to a much lesser extent. Surprisingly, the two cell line models exhibit remarkably similar levels of CIN, as the nuclear areas and CS values are largely overlapping between the corresponding paired lines. Accordingly, these data suggest CIN may represent a novel biomarker capable of monitoring changes in EOC progression associated with drug resistance.

Bitter taste receptors are expressed in human epithelial ovarian and prostate cancers cells and noscapine stimulation impacts cell survival.

Bitter taste receptors (Tas2Rs) are a subfamily of G-protein coupled receptors expressed not only in the oral cavity but also in several extra-oral tissues and disease states. Several natural bitter compounds from plants, such as bitter melon extract and noscapine, have displayed anti-cancer effects against various cancer types. In this study, we examined the prevalence of Tas2R subtype expression in several epithelial ovarian or prostate cancer cell lines, and the functionality of Tas2R14 was determined. qPCR analysis of five TAS2Rs demonstrated that mRNA expression often varies greatly in cancer cells in comparison to normal tissue. Using receptor-specific siRNAs, we also demonstrated that noscapine stimulation of ovarian cancer cells increased apoptosis in ovarian cancer cells in a receptor-dependent, but ROS-independent manner. This study furthers our understanding of the function of Tas2Rs in ovarian cancer by demonstrating that their activation has an impact on cell survival.

Characteristics and outcome of the COEUR Canadian validation cohort for ovarian cancer biomarkers.

BACKGROUND: Ovarian carcinoma is the most lethal gynecological malignancy due to early dissemination and acquired resistance to platinum-based chemotherapy. Reliable markers that are independent and complementary to clinical parameters are needed to improve the management of patients with this disease. The Canadian Ovarian Experimental Unified Resource (COEUR) provides researchers with biological material and associated clinical data to conduct biomarker validation studies. Using standards defined by the Canadian Tissue Repository Network (CTRNet), we have previously demonstrated the quality of the biological material from this resource. Here we describe the clinical characteristics of the COEUR cohort. METHODS: With support from 12 Canadian ovarian cancer biobanks in Canada, we created a central retrospective cohort comprised of more than 2000 patient tissue samples with associated clinical data, including 1246 high-grade serous, 102 low-grade serous, 295 endometrioid, 259 clear cell and 89 mucinous carcinoma histotypes. A two-step reclassification process was applied to assure contemporary histological classification (histotyping). For each histotypes individually, we evaluated the association between the known clinico-pathological parameters (stage, cytoreduction, chemotherapy treatment, BRCA1 and BRCA2 mutation) and patient outcome by using Kaplan-Meier and Cox proportional hazard regression analyses. RESULTS: The median follow-up time of the cohort was 45 months and the 5-year survival rate for patients with high-grade serous carcinomas was 34%, in contrast to endometrioid carcinomas with 80% at 5 years. Survival profiles differed by histotype when stratified by stage or cytoreduction. Women with mucinous or clear cell carcinomas at advanced stage or with non-optimally debulked disease had the worst outcomes. In high-grade serous carcinoma, we observed significant association with longer survival in women harboring BRCA1 or BRCA2 mutation as compared to patients without detectable mutation. CONCLUSIONS: Our results show the expected survival rates, as compared with current literature, in each histotype suggesting that the cohort is an unbiased representation of the five major histotypes. COEUR, a one stop comprehensive biorepository, has collected mature outcome data and relevant clinical data in a comprehensive manner allowing stratified analysis.

Rate of Appendiceal Metastasis with Non-Serous Epithelial Ovarian Cancer in Manitoba.

OBJECTIVE: This study sought to evaluate the rate of appendiceal involvement in non-serous mucinous and endometrioid-associated epithelial ovarian cancers. METHODS: The Manitoba Cancer Registry and CancerCare database were used to find all women with non-serous epithelial ovarian, fallopian tube, or primary peritoneal cancer between 1995 and 2011. All patients with an appendectomy were then identified, and their final pathology findings were reviewed. Women who did not receive treatment or lacked follow-up were excluded. RESULTS: We identified 338 patients from 1995-2011 with no prior appendectomy. Of these, 16.6% received an appendectomy, and 22.8% were clinically evaluated. Most cases within this cohort were mucinous (62%) and stage 1 (63%). Four appendiceal metastases were identified (7.2%), and one half appeared clinically normal at the time of surgery (3.6%). Within the mucinous histologic type, 32.7% of patients received an appendectomy, with a metastatic rate of 5.7%. Of the 127 endometrioid cases, only 10 patients received an appendectomy, and 2 were found to have metastases. No metastases were found in the 85 patients in the clear cell cohort, only 5 of whom received an appendectomy. CONCLUSION: Routine appendectomy or clinical assessment of the appendix is valuable for all non-serous ovarian cancers. The rate of involvement for endometriosis-associated ovarian cancers may be significantly higher than expected, and further studies need to be conducted.

Examining the Selection Criteria of Neoadjuvant Chemotherapy Patients.

OBJECTIVES: To identify predictors of neoadjuvant chemotherapy (NAC) and to examine toxicities, dose reduction, interruptions, and second-line chemotherapy MATERIALS AND METHODS: A retrospective chart review of 391 patients with late-stage ovarian cancer diagnosed between January 1, 2004 and December 31, 2010 was conducted. Logistic regression was used to predict chemotherapy type. Cumulative incidence of toxicities, dose reduction, and treatment interruption were calculated using the Kaplan-Meier method. Overall survival was analyzed using time-varying Cox regression models. A competing risk model was used to predict second-line chemotherapy with death as a competing risk. RESULTS: Older patients were less likely to receive primary debulking (OR 0.710; 95% CI 0.55-0.92, P = 0.0108), as were patients with longer diagnostic intervals. Clear-cell, endometrioid, and mucinous carcinoma were more likely to receive adjuvant treatment than unclassified epithelial (OR 6.964; 95% CI 2.02-24.03, P = 0.0021). Adjuvant patients experienced higher incidence of chemotherapy toxicities (P <0.0001) and treatment interruption (P = 0.016) at 3 months. There was no statistically significant difference in the incidence of chemotherapy dose reduction of >20% in the NAC and adjuvant populations (P = 0.142). Neoadjuvant patients were more likely to require more than one line of chemotherapy ([Subhazard Ratio] = 4.334; 95% CI 2.51-7.50, P <0.0001). CONCLUSION: Our study found that patients with shorter diagnostic intervals, more advanced age, and unclassified epithelial histotype were more likely to receive NAC. NAC patients did not experience a higher incidence of chemotherapy toxicities, treatment interruption, or dose reduction. There is treatment selection bias for sicker patients being treated with NAC.

Examining the Effects of Time to Diagnosis, Income, Symptoms, and Incidental Detection on Overall Survival in Epithelial Ovarian Cancer: Manitoba Ovarian Cancer Outcomes (MOCO) Study Group.

OBJECTIVE: The primary objectives of this study were to analyze data on time to diagnosis and correlate this with overall survival. We secondarily analyzed the effects of emergency room visits, symptoms, incidental findings, residence, socioeconomic status, and residual disease on overall survival. METHODS: This retrospective population-based descriptive cohort study examined all invasive ovarian cancer cases in Manitoba, Canada, between 2004 and 2010. Clinicopathologic, socioeconomic, and outcome data were collected. Analysis was performed with Cox and logistic regression stratified by early and late stage. RESULTS: Six hundred eighty-seven ovarian cancer patients were identified, with a final cohort of 601 patients: 210 with early-stage (1/2) and 391 with late-stage (3/4) disease. No presenting symptoms were associated with survival outcome. Poorer survival was associated with increasing age (P = 0.0016) and neoadjuvant chemotherapy (P = 0.0037). Higher income within the urban setting was also associated with a survival advantage (P = 0.0037), whereas initial presentation to the emergency room (P = 0.0399) was associated with decreased survival. Finally, for advanced-stage disease, incidental diagnosis had a significantly improved overall survival (hazard ratio, 0.424; 95% confidence interval, 0.27-0.67; P = 0.0003), even when accounting for confounding factors. Time from first presentation to diagnosis was associated with survival (P = 0.0309). CONCLUSIONS: This study found that time to diagnosis did not negatively impact overall survival, although there was an association. Age, morphology, treatment type, residual disease, medical comorbidities, and income were significant prognostic factors. This is the first study to show a survival advantage to incidentally finding an ovarian cancer. Further research is needed on the outcomes of pelvic examination.

Differential cellular responses induced by dorsomorphin and LDN-193189 in chemotherapy-sensitive and chemotherapy-resistant human epithelial ovarian cancer cells.

Inherent or acquired drug resistance is a major contributor to epithelial ovarian cancer (EOC) mortality. Novel drugs or drug combinations that produce EOC cell death or resensitize drug resistant cells to standard chemotherapy may improve patient treatment. After conducting drug tolerability studies for the multikinase inhibitors dorsomorphin (DM) and it is structural analogue LDN-193189 (LDN), these drugs were tested in a mouse intraperitoneal xenograft model of EOC. DM significantly increased survival, whereas LDN showed a trend toward increased survival. In vitro experiments using cisplatin (CP)-resistant EOC cell lines, A2780-cp or SKOV3, we determined that pretreatment or cotreatment with DM or LDN resensitized cells to the killing effect of CP or carboplatin (CB). DM was capable of blocking EOC cell cycle and migration, whereas LDN produced a less pronounced effect on cell cycle and no effect on migration. Subsequent analyses using primary human EOC cell samples or additional established EOC cells lines showed that DM or LDN induced a dose-dependent autophagic or cell death response, respectively. DM induced a characteristic morphological change with the appearance of numerous LC3B-containing acidic vacuoles and an increase in LC3BII levels. This was coincident with a decrease in cell growth and the altered cell cycle consistent with DM-induced cytostasis. By contrast, LDN produced a caspase 3-independent, reactive oxygen species-dependent cell death. Overall, DM and LDN possess drug characteristics suitable for adjuvant agents used to treat chemotherapy-sensitive and -resistant EOC.

Ovarian Cancer in the Older Manitoban Population-Treatment Tolerance and Cancer-Related Outcomes: A Manitoba Ovarian Cancer Outcomes (MOCO) Group Study.

BACKGROUND: In Canada, individuals with gynecologic reproductive organs (ovaries, fallopian tubes, uterus) over the age of 70 comprise a large proportion of epithelial ovarian cancer patients. These patients often have co-morbidities, polypharmacy, or decreased functional status that may impact treatment initiation and tolerance. Despite this, there is limited evidence to guide treatment for older patients diagnosed with ovarian epithelial carcinoma. METHODS: This is a retrospective study with data from Manitoba, Canada. The data were obtained from the Manitoba Ovarian Cancer Database, the Manitoba Cancer Registry, and electronic health records. All individuals with epithelial ovarian, fallopian tube, or peritoneal cancer diagnosed between 2009 and 2018 were identified. Patients aged > 70 at the time of diagnosis were included in the study cohort. RESULTS: Four hundred and forty individuals were included. The majority had advanced stage disease (56%). Moreover, 59% of patients received no chemotherapy. Of the patients who received chemotherapy, 20% received <2 cycles and 21% required a dose reduction due to toxicity. Univariable and multivariable analysis identified advanced stage (p < 0.001), treatment modality (p < 0.001), and advanced age at diagnosis (p < 0.001) with poorer overall survival. CONCLUSIONS: Our study demonstrated a high rate of chemotherapy dose reduction and discontinuation in the elderly epithelial ovarian cancer population. Further research is needed to identify risk factors for treatment discontinuation and intolerance in this population.

The Potential of Novel Lipid Agents for the Treatment of Chemotherapy-Resistant Human Epithelial Ovarian Cancer.

Recurrent epithelial ovarian cancer (EOC) coincident with chemotherapy resistance remains the main contributor to patient mortality. There is an ongoing investigation to enhance patient progression-free and overall survival with novel chemotherapeutic delivery, such as the utilization of antiangiogenic medications, PARP inhibitors, or immune modulators. Our preclinical studies highlight a novel tool to combat chemotherapy-resistant human EOC. Glycosylated antitumor ether lipids (GAELs) are synthetic glycerolipids capable of killing established human epithelial cell lines from a wide variety of human cancers, including EOC cell lines representative of different EOC histotypes. Importantly, GAELs kill high-grade serous ovarian cancer (HGSOC) cells isolated from the ascites of chemotherapy-sensitive and chemotherapy-resistant patients grown as monolayers of spheroid cultures. In addition, GAELs were well tolerated by experimental animals (mice) and were capable of reducing tumor burden and blocking ascites formation in an OVCAR-3 xenograft model. Overall, GAELs show great promise as adjuvant therapy for EOC patients with or without chemotherapy resistance.

Referral, Genetic Counselling, and BRCA Testing in the Manitoba High-Grade Serous Ovarian Cancer Population, 2004-2019.

(1) Background: The primary objective of this study was to examine the rate of genetic referral, BRCA testing, and BRCA positivity amongst all patients with high-grade serous ovarian cancers (HGSOC) from 2004-2019. The secondary objective was to analyze secondary factors that may affect the rates of referral and testing. (2) Methods: This population-based cohort study included all women diagnosed with HGSOC using the Manitoba Cancer Registry, CervixCheck registry, Medical Claims database at Manitoba Health, the Hospital Discharge abstract, the Population Registry, and Winnipeg Regional Health Authority genetics data. Data were examined for three different time cohorts (2004-2013, 2014-2016; 2017-2019) correlating to practice pattern changes. (3) Results: A total of 944 patients were diagnosed with HGSOC. The rate of genetic referrals changed over the three timeframes (20.0% → 56.7% → 36.6%) and rate of genetic testing increased over the entire timeframe. Factors found to increase rates of referral and testing included age, histology, history of oral contraceptive use, and family history of ovarian cancer. Prior health care utilization indicators did not affect genetic referral or testing. (4) Conclusion: The rate of genetic referral (2004-2016) and BRCA1/2 testing (2004-2019) for patients with a diagnosis of HGSOC increased over time. A minority of patients received a consultation for genetics counselling, and even fewer received testing for a BRCA1/2. Without a genetic result, it is difficult for clinicians to inform treatment decisions. Additional efforts are needed to increase genetics consultation and testing for Manitoban patients with HGSOC. Effects of routine tumour testing on rates of genetic referral will have to be examined in future studies.

Pcsk6 mutant mice exhibit progressive loss of ovarian function, altered gene expression, and formation of ovarian pathology.

Bioactivation of precursor proteins by members of the proprotein convertase (PC) family is essential for normal reproduction. The Pcsk6 gene is a member of the PC family that is expressed in numerous ovarian cell types including granulosa cells and oocytes. We hypothesized that loss of PCSK6 would produce adverse effects in the mouse ovary. Mice incapable of expressing PCSK6 (Pcsk6(tm1Rob)) were obtained, and reproductive parameters (serum hormones, whelping interval, estrus cyclicity, and fertility) were compared to Pcsk6(+/+) mice. While Pcsk6(tm1Rob) female mice are fertile, they manifest reduced reproductive capacity at an accelerated rate relative to Pcsk6(+/+) mice. Reproductive senescence is typically reached by 9 months of age and is correlated with loss of estrus cyclicity, elevated serum FSH levels, and gross alterations in ovarian morphology. A wide range of ovarian morphologies were identified encompassing mild, such as an apparent reduction in follicle number, to moderate--ovarian atrophy with a complete absence of follicles--to severe, manifesting as normal ovarian structures replaced by benign ovarian tumors, including tubulostromal adenomas. Targeted gene expression profiling highlighted changes in RNA expression of molecules involved in processes such as steroidogenesis, gonadotropin signaling, transcriptional regulation, autocrine/paracrine signaling, cholesterol handling, and proprotein bioactivation. These results show that PCSK6 activity plays a role in maintaining normal cellular and tissue homeostasis in the ovary.

Ubiquitin Proteasome Pathway Transcriptome in Epithelial Ovarian Cancer.

In this article, we reviewed the transcription of genes coding for components of the ubiquitin proteasome pathway in publicly available datasets of epithelial ovarian cancer (EOC). KEGG analysis was used to identify the major pathways distinguishing EOC of low malignant potential (LMP) from invasive high-grade serous ovarian carcinomas (HGSOC), and to identify the components of the ubiquitin proteasome system that contributed to these pathways. We identified elevated transcription of several genes encoding ubiquitin conjugases associated with HGSOC. Fifty-eight genes coding for ubiquitin ligases and more than 100 genes encoding ubiquitin ligase adaptors that were differentially expressed between LMP and HGSOC were also identified. Many differentially expressed genes encoding E3 ligase adaptors were Cullin Ring Ligase (CRL) adaptors, and 64 of them belonged to the Cullin 4 DCX/DWD family of CRLs. The data suggest that CRLs play a role in HGSOC and that some of these proteins may be novel therapeutic targets. Differential expression of genes encoding deubiquitinases and proteasome subunits was also noted.

Cytotoxic capacity of a novel glycosylated antitumor ether lipid in chemotherapy-resistant high grade serous ovarian cancer in vitro and in vivo.

Chemotherapy resistant high grade serous ovarian cancer remains a clinically intractable disease with a high rate of mortality. We tested a novel glycosylated antitumor ether lipid called l-Rham to assess the in vitro and in vivo efficacy on high grade serous ovarian cancer cell lines and patient samples. l-Rham effectively kills high grade serous ovarian cancer cells grown as 2D or 3D cultures in a dose and time dependent manner. l-Rham efficacy was tested in vivo in a chicken allantoic membrane/COV362 xenograft model, where l-Rham activity was as effective as paclitaxel in reducing tumor weight and metastasis. The efficacy of l-Rham to reduce OVCAR3 tumor xenografts in NRG mice was assessed in low and high tumor burden models. l-Rham effectively reduced tumor formation in the low tumor burden group, and blocked ascites formation in low and high tumor burden animals. l-Rham demonstrates efficacy against OVCAR3 tumor and ascites formation in vivo in NRG mice, laying the foundation for further development of this drug class for the treatment of high grade serous ovarian cancer patients.

Reduced RBX1 expression induces chromosome instability and promotes cellular transformation in high-grade serous ovarian cancer precursor cells.

Despite high-grade serous ovarian cancer (HGSOC) being the most common and lethal gynecological cancer in women, the early etiological events driving disease development remain largely unknown. Emerging evidence now suggests that chromosome instability (CIN; ongoing changes in chromosome numbers) may play a central role in the development and progression of HGSOC. Importantly, genomic amplification of the Cyclin E1 gene (CCNE1) contributes to HGSOC pathogenesis in ~20% of patients, while Cyclin E1 overexpression induces CIN in model systems. Cyclin E1 levels are normally regulated by the SCF (SKP1-CUL1-FBOX) complex, an E3 ubiquitin ligase that includes RBX1 as a core component. Interestingly, RBX1 is heterozygously lost in ~80% of HGSOC cases and reduced expression corresponds with worse outcomes, suggesting it may be a pathogenic event. Using both short (siRNA) and long (CRISPR/Cas9) term approaches, we show that reduced RBX1 expression corresponds with significant increases in CIN phenotypes in fallopian tube secretory epithelial cells, a cellular precursor of HGSOC. Moreover, reduced RBX1 expression corresponds with increased Cyclin E1 levels and anchorage-independent growth. Collectively, these data identify RBX1 as a novel CIN gene with pathogenic implications for HGSOC.