Precious GEMMs: emergence of faithful models for ovarian cancer research.

The development of Genetically Engineered Mouse Models (GEMMs) has catalyzed tremendous progress in cancer research. However, it has been difficult to design adequate mouse models for high-grade serous carcinoma (HGSC), the most common and lethal form of ovarian cancer. The genetic complexity of the disease, as well as the recent appreciation that most HGSCs arise from the fallopian tube (FT) secretory epithelium rather than the ovarian surface epithelium, has stifled the development of robust GEMMs. In a recent issue of this journal, Zhai et al presented an elegant mouse model for ovarian cancer that uses Ovgp1 as an FT-specific promoter to inactivate Brca1, Trp53, Rb1, Nf1, and Pten. The authors showed that loss of these genes in the mouse FT epithelium can mimic the different stages of human HGSC tumorigenesis. Their robust model emphasizes the importance of considering both the cell of origin and tumor genetics in developing accurate model systems. They provide a useful tool for studying mechanisms of disease in vivo and for research into novel methods of prevention, early detection, and treatment of HGSC. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Primordial germ cells as a potential shared cell of origin for mucinous cystic neoplasms of the pancreas and mucinous ovarian tumors.

Mucinous ovarian tumors (MOTs) morphologically and epidemiologically resemble mucinous cystic neoplasms (MCNs) of the pancreas, sharing a similar stroma and both occurring disproportionately among young females. Additionally, MOTs and MCNs share similar clinical characteristics and immunohistochemical phenotypes. Exome sequencing has revealed frequent recurrent mutations in KRAS and RNF43 in both MOTs and MCNs. The cell of origin for these tumors remains unclear, but MOTs sometimes arise in the context of mature cystic teratomas and other primordial germ cell (PGC) tumors. We undertook the present study to investigate whether non-teratoma-associated MOTs and MCNs share a common cell of origin. Comparisons of the gene expression profiles of MOTs [including both the mucinous borderline ovarian tumors (MBOTs) and invasive mucinous ovarian carcinomas (MOCs)], high-grade serous ovarian carcinomas, ovarian surface epithelium, Fallopian tube epithelium, normal pancreatic tissue, pancreatic duct adenocarcinomas, MCNs, and single-cell RNA-sequencing of PGCs revealed that both MOTs and MCNs are more closely related to PGCs than to either eutopic epithelial tumors or normal epithelia. We hypothesize that MCNs may arise from PGCs that stopped in the dorsal pancreas during their descent to the gonads during early human embryogenesis, while MOTs arise from PGCs in the ovary. Together, these data suggest a common pathway for the development of MCNs and MOTs, and suggest that these tumors may be more properly classified as germ cell tumor variants. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

L1CAM is required for early dissemination of fallopian tube carcinoma precursors to the ovary.

Most ovarian high-grade serous carcinomas (HGSC) arise from Serous Tubal Intraepithelial Carcinoma (STIC) lesions in the distal end of the fallopian tube (FT). Formation of STIC lesions from FT secretory cells leads to seeding of the ovarian surface, with rapid tumor dissemination to other abdominal structures thereafter. It remains unclear how nascent malignant cells leave the FT to colonize the ovary. This report provides evidence that the L1 cell adhesion molecule (L1CAM) contributes to the ability of transformed FT secretory cells (FTSEC) to detach from the tube, survive under anchorage-independent conditions, and seed the ovarian surface. L1CAM was highly expressed on the apical cells of STIC lesions and contributed to ovarian colonization by upregulating integrins and fibronectin in malignant cells and activating the AKT and ERK pathways. These changes increased cell survival under ultra-low attachment conditions that mimic transit from the FT to the ovary. To study dissemination to the ovary, we developed a tumor-ovary co-culture model. We showed that L1CAM expression was important for FT cells to invade the ovary as a cohesive group. Our results indicate that in the early stages of HGSC development, transformed FTSECs disseminate from the FT to the ovary in a L1CAM-dependent manner.

SARS-CoV-2 Vaccine Willingness among Pregnant and Breastfeeding Women during the First Pandemic Wave: A Cross-Sectional Study in Switzerland.

As pregnant women are at high risk of severe SARS-CoV-2 infection and COVID-19 vaccines are available in Switzerland, this study aimed to assess the willingness of Swiss pregnant and breastfeeding women to become vaccinated. Through a cross-sectional online study conducted after the first pandemic wave, vaccination practices and willingness to become vaccinated against SARS-CoV-2 if a vaccine was available were evaluated through binary, multi-choice, and open-ended questions. Factors associated with vaccine willingness were evaluated through univariable and multivariable analysis. A total of 1551 women responded to questions related to the primary outcome. Only 29.7% (153/515) of pregnant and 38.6% (400/1036) of breastfeeding women were willing to get vaccinated against SARS-CoV-2 if a vaccine had been available during the first wave. Positive predictors associated with SARS-CoV-2 vaccine acceptance were an age older than 40 years, a higher educational level, history of influenza vaccination within the previous year, having an obstetrician as the primary healthcare practitioner, and being in their third trimester of pregnancy. After the first pandemic wave, Switzerland had a low SARS-CoV-2 vaccination acceptance rate, emphasizing the need to identify and reduce barriers for immunization in pregnant and breastfeeding women, particularly among the youngest and those with a lower educational level.

Current Data on COVID-19 mRNA-Vaccine Safety during Pregnancy Might Be Subject to Selection Bias. Reply to Stroobandt, S.; Stroobandt, R. Data of the COVID-19 mRNA-Vaccine V-Safe Surveillance System and Pregnancy Registry Reveals Poor Embryonic and Second Trimester Fetal Survival Rate. Comment on "Stuckelberger et al. SARS-CoV-2 Vaccine Willingness among Pregnant and Breastfeeding Women during the First Pandemic Wave: A Cross-Sectional Study in Switzerland. Viruses 2021, 13, 1199".

We would like to thank Stroobandt, S. and Stroobandt, R. for showing interest in our paper [...].

Intra-Tumoral Nerve-Tracing in a Novel Syngeneic Model of High-Grade Serous Ovarian Carcinoma.

Dense tumor innervation is associated with enhanced cancer progression and poor prognosis. We observed innervation in breast, prostate, pancreatic, lung, liver, ovarian, and colon cancers. Defining innervation in high-grade serous ovarian carcinoma (HGSOC) was a focus since sensory innervation was observed whereas the normal tissue contains predominantly sympathetic input. The origin, specific nerve type, and the mechanisms promoting innervation and driving nerve-cancer cell communications in ovarian cancer remain largely unknown. The technique of neuro-tracing enhances the study of tumor innervation by offering a means for identification and mapping of nerve sources that may directly and indirectly affect the tumor microenvironment. Here, we establish a murine model of HGSOC and utilize image-guided microinjections of retrograde neuro-tracer to label tumor-infiltrating peripheral neurons, mapping their source and circuitry. We show that regional sensory neurons innervate HGSOC tumors. Interestingly, the axons within the tumor trace back to local dorsal root ganglia as well as jugular-nodose ganglia. Further manipulations of these tumor projecting neurons may define the neuronal contributions in tumor growth, invasion, metastasis, and responses to therapeutics.

Location of Mutation in BRCA2 Gene and Survival in Patients with Ovarian Cancer.

Purpose: BRCA2 plays a central role in homologous recombination by loading RAD51 on DNA breaks. The objective of this study is to determine whether the location of mutations in the RAD51-binding domain (RAD51-BD; exon 11) of BRCA2 gene affects the clinical outcome of ovarian cancer patients.Experimental Design: A study cohort of 353 women with ovarian cancer who underwent genetic germline testing for BRCA1 and BRCA2 genes was identified. Progression-free survival (PFS), platinum-free interval (PFI), and overall survival (OS) were analyzed. The Cancer Genome Atlas (TCGA) cohort of ovarian cancer (n = 316) was used as a validation cohort.Results: In the study cohort, 78 patients were carriers of germline mutations of BRCA2 After adjustment for FIGO stage and macroscopic residual disease, BRCA2 carriers with truncating mutations in the RAD51-BD have significantly prolonged 5-year PFS [58%; adjusted HR, 0.36; 95% confidence interval (CI), 0.20-0.64; P = 0.001] and prolonged PFI (29.7 vs. 15.5 months, P = 0.011), compared with noncarriers. BRCA2 carriers with mutations located in other domains of the gene do not have prolonged 5-year PFS (28%, adjusted HR, 0.67; 95% CI, 0.42-1.07; P = 0.094) or PFI (19 vs. 15.5 months, P = 0.146). In the TCGA cohort, only BRCA2 carriers harboring germline or somatic mutations in the RAD51-BD have prolonged 5-year PFS (46%; adjusted HR, 0.30; 95% CI, 0.13-0.68; P = 0.004) and 5-year OS (78%; adjusted HR, 0.09; 95% CI, 0.02-0.38; P = 0.001).Conclusions: Among ovarian cancer patients, BRCA2 carriers with mutations located in the RAD51-BD (exon 11) have prolonged PFS, PFI, and OS. Clin Cancer Res; 24(2); 326-33. ©2017 AACR.