Mark William Nachtigal

The noncoding RNA BC200 is elevated in human cancers and is implicated in translation regulation as well as cell survival and proliferation. Upon BC200 overexpression, we observed correlated expression of a second, smaller RNA species. This RNA is expressed endogenously and exhibits cell-type-dependent variability relative to BC200. Aptamer-tagged expression constructs confirmed that the RNA is a truncated form of BC200, and sequencing revealed a modal length of 120 nt; thus, we refer to the RNA fragment as BC120. We present a methodology for accurate and specific detection of BC120 and establish that BC120 is expressed in several normal human tissues and is also elevated in ovarian cancer. BC120 exhibits remarkable stability relative to BC200 and is resistant to knockdown strategies that target the 3′ unique sequence of BC200. Combined knockdown of BC200 and BC120 exhibits greater phenotypic impacts than knockdown of BC200 alone, and overexpression of BC120 negatively impacts translation of a GFP reporter, providing insight into a potential translational regulatory role for this RNA. The presence of a novel, truncated, and stable form of BC200 adds complexity to the investigation of this noncoding RNA that must be considered in future studies of BC200 and other related Alu RNAs.

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 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.

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.

(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.

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.

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.

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.