NRG-GY012: Randomized phase 2 study comparing olaparib, cediranib, and the combination of cediranib/olaparib in women with recurrent, persistent, or metastatic endometrial cancer.

PURPOSE: This paper reports the efficacy of the poly (ADP-ribose) polymerase inhibitor olaparib alone and in combination with the antiangiogenesis agent cediranib compared with cediranib alone in patients with advanced endometrial cancer. METHODS: This was open-label, randomized, phase 2 trial (NCT03660826). Eligible patients had recurrent endometrial cancer, received at least one (<3) prior lines of chemotherapy, and were Eastern Cooperative Oncology Group performance status 0 to 2. Patients were randomly assigned (1:1:1), stratified by histology (serous vs. other) to receive cediranib alone (reference arm), olaparib, or olaparib and cediranib for 28-day cycles until progression or unacceptable toxicity. The primary end point was progression-free survival in the intention-to-treat population. Homologous repair deficiency was explored using the BROCA-GO sequencing panel. RESULTS: A total of 120 patients were enrolled and all were included in the intention-to-treat analysis. Median age was 66 (range, 41-86) years and 47 (39.2%) had serous histology. Median progression-free survival for cediranib was 3.8 months compared with 2.0 months for olaparib (hazard ratio, 1.45 [95% CI, 0.91-2.3] p = .935) and 5.5 months for olaparib/cediranib (hazard ratio, 0.7 [95% CI, 0.43-1.14] p = .064). Four patients receiving the combination had a durable response lasting more than 20 months. The most common grade 3/4 toxicities were hypertension in the cediranib (36%) and olaparib/cediranib (33%) arms, fatigue (20.5% olaparib/cediranib), and diarrhea (17.9% cediranib). The BROCA-GO panel results were not associated with response. CONCLUSION: The combination of cediranib and olaparib demonstrated modest clinical efficacy; however, the primary end point of the study was not met. The combination was safe without unexpected toxicity.

Extended Venous Thromboembolism Prophylaxis after Robotic Staging for Endometrial Cancer.

OBJECTIVES: Our objectives were to estimate the incidence of venous thromboembolism (VTE) after robotic staging for endometrial cancer and to compare the incidence of VTE in patients who received a single dose of preoperative prophylaxis of enoxaparin with those who received extended postoperative prophylaxis. METHODS: This study is a retrospective chart review of patients who underwent robot-assisted surgical staging for endometrial cancer. Patients were categorized into two groups: preoperative prophylaxis (PP), patients who received a single dose of enoxaparin preoperatively, and extended prophylaxis (EP), patients who received 28 days of enoxaparin postoperatively. RESULTS: In total, 148 patients were included, with 117 patients in the PP group and 31 patients in the EP group. The overall incidence of VTE within 30 days postoperatively was 0.67%. No significant difference was found between the PP and the EP groups (0.9% and 0%, respectively; P = 1.00). Most patients in the cohort had endometrioid adenocarcinoma (78%) with low-grade disease (70%), although there were a greater number of patients in the PP group with uterine serous carcinoma compared with the EP group (17% vs 10%; P = 0.034). The PP group had higher estimated blood loss (106 vs 81 mL; P = 0.009) and longer operative times (178 vs 151 min; P = 0.028) compared with the EP group. Significantly more patients in the PP group underwent lymph node dissection compared with the EP group (32% vs 7%; P = 0.008). CONCLUSIONS: The incidence of VTE following robot-assisted surgical staging for endometrial cancer in this study was 0.67%. No significant difference was found in VTE incidence between the PP group compared with the EP group. Mechanical prophylaxis plus a single dose of preoperative pharmacologic prophylaxis may suffice for low-risk patients following robotic surgical staging for endometrial cancer.

Sentinel Lymph Node Sampling in Robot-Assisted Staging of Endometrial Cancer.

OBJECTIVE: Sentinel lymph node (SLN) sampling in endometrial cancer staging has become an acceptable standard. Indocyanine green dye injected into the cervix and detected by near-infrared light is technically simple and sensitive. We aimed to evaluate SLN sampling in robot-assisted surgical staging of endometrial cancer at a university-affiliated teaching hospital. METHODS: A retrospective chart review, from January 2016 to December 2017, of patients who underwent robot-assisted surgical staging with cervical injection of indocyanine green dye detected by near-infrared light. The map rate, sensitivity, false negatives, and negative predictive value were calculated. RESULTS: A total of 105 charts were reviewed; 79 patients met inclusion criteria. The mean age was 65 (range 38-93) and the mean body mass index was 33.3 (range 16-49). Most patients (72.2%) had stage I disease and grade 1 or 2 histology (77.1%). Eight (10.1%) patients had lymph node metastasis. Seventy-two (91.1%) patients had positive mapping to at least 1 SLN. Sixty-two (78.5%) patients had bilateral mapping. Forty-four patients had concurrent pelvic ± para-aortic lymph node dissection and were included in the sensitivity analysis. Five of 44 cases had LN metastasis. The sensitivity was 80%, and the negative predictive value of SLN sampling was 97.5%. CONCLUSIONS: SLN mapping and sampling at a university-affiliated teaching hospital have comparable map rate, sensitivity, and negative predictive value as demonstrated in multiple trials. The technique has the potential to standardize endometrial cancer staging across different practice settings.

EZH2 Inhibition Sensitizes CARM1-High, Homologous Recombination Proficient Ovarian Cancers to PARP Inhibition.

In response to DNA double-strand breaks, MAD2L2-containing shieldin complex plays a critical role in the choice between homologous recombination (HR) and non-homologous end-joining (NHEJ)-mediated repair. Here we show that EZH2 inhibition upregulates MAD2L2 and sensitizes HR-proficient epithelial ovarian cancer (EOC) to poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitor in a CARM1-dependent manner. CARM1 promotes MAD2L2 silencing by driving the switch from the SWI/SNF complex to EZH2 through methylating the BAF155 subunit of the SWI/SNF complex on the MAD2L2 promoter. EZH2 inhibition upregulates MAD2L2 to decrease DNA end resection, which increases NHEJ and chromosomal abnormalities, ultimately causing mitotic catastrophe in PARP inhibitor treated HR-proficient cells. Significantly, EZH2 inhibitor sensitizes CARM1-high, but not CARM-low, EOCs to PARP inhibitors in both orthotopic and patient-derived xenografts.

NAMPT Inhibition Suppresses Cancer Stem-like Cells Associated with Therapy-Induced Senescence in Ovarian Cancer.

Epithelial ovarian cancer (EOC) is the most lethal of gynecologic malignancies. The standard-of-care treatment for EOC is platinum-based chemotherapy such as cisplatin. Platinum-based chemotherapy induces cellular senescence. Notably, therapy-induced senescence contributes to chemoresistance by inducing cancer stem-like cells (CSC). However, therapeutic approaches targeting senescence-associated CSCs remain to be explored. Here, we show that nicotinamide phosphoribosyltransferase (NAMPT) inhibition suppresses senescence-associated CSCs induced by platinum-based chemotherapy in EOC. Clinically applicable NAMPT inhibitors suppressed the outgrowth of cisplatin-treated EOC cells both in vitro and in vivo. Moreover, a combination of the NAMPT inhibitor FK866 and cisplatin improved the survival of EOC-bearing mice. These phenotypes correlated with inhibition of the CSCs signature, which consists of elevated expression of ALDH1A1 and stem-related genes, high aldehyde dehydrogenase activity, and CD133 positivity. Mechanistically, NAMPT regulates EOC CSCs in a paracrine manner through the senescence-associated secretory phenotype. Our results suggest that targeting NAMPT using clinically applicable NAMPT inhibitors, such as FK866, in conjunction with platinum-based chemotherapy represents a promising therapeutic strategy by suppressing therapy-induced senescence-associated CSCs. SIGNIFICANCE: This study highlights the importance of NAMPT-mediated NAD+ biosynthesis in the production of cisplatin-induced senescence-associated cancer stem cells, as well as tumor relapse after cisplatin treatment.

Drug-induced chromatin accessibility changes associate with sensitivity to liver tumor promotion.

Liver cancer susceptibility varies amongst humans and between experimental animal models because of multiple genetic and epigenetic factors. The molecular characterization of such susceptibilities has the potential to enhance cancer risk assessment of xenobiotic exposures and disease prevention strategies. Here, using DNase I hypersensitivity mapping coupled with transcriptomic profiling, we investigate perturbations in cis-acting gene regulatory elements associated with the early stages of phenobarbital (PB)-mediated liver tumor promotion in susceptible versus resistant mouse strains (B6C3F1 versus C57BL/6J). Integrated computational analyses of strain-selective changes in liver chromatin accessibility underlying PB response reveal differential epigenetic regulation of molecular pathways associated with PB-mediated tumor promotion, including Wnt/ß-catenin signaling. Complementary transcription factor motif analyses reveal mouse strain-selective gene regulatory networks and a novel role for Stat, Smad, and Fox transcription factors in the early stages of PB-mediated tumor promotion. Mapping perturbations in cis-acting gene regulatory elements provides novel insights into the molecular basis for susceptibility to xenobiotic-induced rodent liver tumor promotion and has the potential to enhance mechanism-based cancer risk assessments of xenobiotic exposures.

ARID1A promotes genomic stability through protecting telomere cohesion.

ARID1A inactivation causes mitotic defects. Paradoxically, cancers with high ARID1A mutation rates typically lack copy number alterations (CNAs). Here, we show that ARID1A inactivation causes defects in telomere cohesion, which selectively eliminates gross chromosome aberrations during mitosis. ARID1A promotes the expression of cohesin subunit STAG1 that is specifically required for telomere cohesion. ARID1A inactivation causes telomere damage that can be rescued by STAG1 expression. Colony formation capability of single cells in G2/M, but not G1 phase, is significantly reduced by ARID1A inactivation. This correlates with an increase in apoptosis and a reduction in tumor growth. Compared with ARID1A wild-type tumors, ARID1A-mutated tumors display significantly less CNAs across multiple cancer types. Together, these results show that ARID1A inactivation is selective against gross chromosome aberrations through causing defects in telomere cohesion, which reconciles the long-standing paradox between the role of ARID1A in maintaining mitotic integrity and the lack of genomic instability in ARID1A-mutated cancers.

CLIC1 and CLIC4 complement CA125 as a diagnostic biomarker panel for all subtypes of epithelial ovarian cancer.

New plasma and tissue biomarkers of epithelial ovarian cancer (EOC) could improve early diagnosis and post-diagnosis clinical management. Here we investigated tissue staining and tissue secretion of CLIC1 and CLIC4 across EOC subtypes. CLIC1 and CLIC4 are two promising biomarkers we previously showed were elevated in EOC patient sera. Individually, CLIC1 or CLIC4 stained larger percentages of malignant tumors across all EOC subtypes compared with CA125, particularly early stage and mucinous tumors. CLIC4 also stained benign tumors but staining was limited to nuclei; whereas malignant tumors showed diffuse cellular staining of stromal and tumor cells. Both proteins were shed by all EOC subtypes tumors in short term organ culture at more consistent levels than CA125, supporting their potential as pan-subtype serum and tissue biomarkers. Elevated CLIC4 expression, but not CLIC1 expression, was a negative indicator of patient survival, and CLIC4 knockdown in cultured cells decreased cell proliferation and migration indicating a potential role in tumor progression. These results suggest CLIC1 and CLIC4 are promising serum and tissue biomarkers as well as potential therapeutic targets for all EOC subtypes. This justifies development of high throughput serum/plasma biomarker assays to evaluate utility of a biomarker panel consisting of CLIC1, CLIC4 and CA125.

SATB1 Expression Governs Epigenetic Repression of PD-1 in Tumor-Reactive T Cells.

Despite the importance of programmed cell death-1 (PD-1) in inhibiting T cell effector activity, the mechanisms regulating its expression remain poorly defined. We found that the chromatin organizer special AT-rich sequence-binding protein-1 (Satb1) restrains PD-1 expression induced upon T cell activation by recruiting a nucleosome remodeling deacetylase (NuRD) complex to Pdcd1 regulatory regions. Satb1 deficienct T cells exhibited a 40-fold increase in PD-1 expression. Tumor-derived transforming growth factor ß (Tgf-ß) decreased Satb1 expression through binding of Smad proteins to the Satb1 promoter. Smad proteins also competed with the Satb1-NuRD complex for binding to Pdcd1 enhancers, releasing Pdcd1 expression from Satb1-mediated repression, Satb1-deficient tumor-reactive T cells lost effector activity more rapidly than wild-type lymphocytes at tumor beds expressing PD-1 ligand (CD274), and these differences were abrogated by sustained CD274 blockade. Our findings suggest that Satb1 functions to prevent premature T cell exhaustion by regulating Pdcd1 expression upon T cell activation. Dysregulation of this pathway in tumor-infiltrating T cells results in diminished anti-tumor immunity.

Screenit: Visual Analysis of Cellular Screens.

High-throughput and high-content screening enables large scale, cost-effective experiments in which cell cultures are exposed to a wide spectrum of drugs. The resulting multivariate data sets have a large but shallow hierarchical structure. The deepest level of this structure describes cells in terms of numeric features that are derived from image data. The subsequent level describes enveloping cell cultures in terms of imposed experiment conditions (exposure to drugs). We present Screenit, a visual analysis approach designed in close collaboration with screening experts. Screenit enables the navigation and analysis of multivariate data at multiple hierarchy levels and at multiple levels of detail. Screenit integrates the interactive modeling of cell physical states (phenotypes) and the effects of drugs on cell cultures (hits). In addition, quality control is enabled via the detection of anomalies that indicate low-quality data, while providing an interface that is designed to match workflows of screening experts. We demonstrate analyses for a real-world data set, CellMorph, with 6 million cells across 20,000 cell cultures.

Regulated large-scale nucleosome density patterns and precise nucleosome positioning correlate with V(D)J recombination.

We show that the physical distribution of nucleosomes at antigen receptor loci is subject to regulated cell type-specific and lineage-specific positioning and correlates with the accessibility of these gene segments to recombination. At the Ig heavy chain locus (IgH), a nucleosome in pro-B cells is generally positioned over each IgH variable (VH) coding segment, directly adjacent to the recombination signal sequence (RSS), placing the RSS in a position accessible to the recombination activating gene (RAG) recombinase. These changes result in establishment of a specific chromatin organization at the RSS that facilitates accessibility of the genomic DNA for the RAG recombinase. In contrast, in mouse embryonic fibroblasts the coding segment is depleted of nucleosomes, which instead cover the RSS, thereby rendering it inaccessible. Pro-T cells exhibit a pattern intermediate between pro-B cells and mouse embryonic fibroblasts. We also find large-scale variations of nucleosome density over hundreds of kilobases, delineating chromosomal domains within IgH, in a cell type-dependent manner. These findings suggest that developmentally regulated changes in nucleosome location and occupancy, in addition to the known chromatin modifications, play a fundamental role in regulating V(D)J recombination. Nucleosome positioning-which has previously been observed to vary locally at individual enhancers and promoters-may be a more general mechanism by which cells can regulate the accessibility of the genome during development, at scales ranging from several hundred base pairs to many kilobases.

CAT7 and cat7l Long Non-coding RNAs Tune Polycomb Repressive Complex 1 Function during Human and Zebrafish Development.

The essential functions of polycomb repressive complex 1 (PRC1) in development and gene silencing are thought to involve long non-coding RNAs (lncRNAs), but few specific lncRNAs that guide PRC1 activity are known. We screened for lncRNAs, which co-precipitate with PRC1 from chromatin and found candidates that impact polycomb group protein (PcG)-regulated gene expression in vivo A novel lncRNA from this screen, CAT7, regulates expression and polycomb group binding at the MNX1 locus during early neuronal differentiation. CAT7 contains a unique tandem repeat domain that shares high sequence similarity to a non-syntenic zebrafish analog, cat7l Defects caused by interference of cat7l RNA during zebrafish embryogenesis were rescued by human CAT7 RNA, enhanced by interference of a PRC1 component, and suppressed by interference of a known PRC1 target gene, demonstrating cat7l genetically interacts with a PRC1. We propose a model whereby PRC1 acts in concert with specific lncRNAs and that CAT7/cat7l represents convergent lncRNAs that independently evolved to tune PRC1 repression at individual loci.

Satb1 Overexpression Drives Tumor-Promoting Activities in Cancer-Associated Dendritic Cells.

Special AT-rich sequence-binding protein 1 (Satb1) governs genome-wide transcriptional programs. Using a conditional knockout mouse, we find that Satb1 is required for normal differentiation of conventional dendritic cells (DCs). Furthermore, Satb1 governs the differentiation of inflammatory DCs by regulating major histocompatibility complex class II (MHC II) expression through Notch1 signaling. Mechanistically, Satb1 binds to the Notch1 promoter, activating Notch expression and driving RBPJ occupancy of the H2-Ab1 promoter, which activates MHC II transcription. However, tumor-driven, unremitting expression of Satb1 in activated Zbtb46(+) inflammatory DCs that infiltrate ovarian tumors results in an immunosuppressive phenotype characterized by increased secretion of tumor-promoting Galectin-1 and IL-6. In vivo silencing of Satb1 in tumor-associated DCs reverses their tumorigenic activity and boosts protective immunity. Therefore, dynamic fluctuations in Satb1 expression govern the generation and immunostimulatory activity of steady-state and inflammatory DCs, but continuous Satb1 overexpression in differentiated DCs converts them into tolerogenic/pro-inflammatory cells that contribute to malignant progression.

Vials: Visualizing Alternative Splicing of Genes.

Alternative splicing is a process by which the same DNA sequence is used to assemble different proteins, called protein isoforms. Alternative splicing works by selectively omitting some of the coding regions (exons) typically associated with a gene. Detection of alternative splicing is difficult and uses a combination of advanced data acquisition methods and statistical inference. Knowledge about the abundance of isoforms is important for understanding both normal processes and diseases and to eventually improve treatment through targeted therapies. The data, however, is complex and current visualizations for isoforms are neither perceptually efficient nor scalable. To remedy this, we developed Vials, a novel visual analysis tool that enables analysts to explore the various datasets that scientists use to make judgments about isoforms: the abundance of reads associated with the coding regions of the gene, evidence for junctions, i.e., edges connecting the coding regions, and predictions of isoform frequencies. Vials is scalable as it allows for the simultaneous analysis of many samples in multiple groups. Our tool thus enables experts to (a) identify patterns of isoform abundance in groups of samples and (b) evaluate the quality of the data. We demonstrate the value of our tool in case studies using publicly available datasets.

Morcellation and the Incidence of Occult Uterine Malignancy: A Dual-Institution Review.

OBJECTIVES: To determine the incidence of unsuspected uterine sarcoma (UtSarc), other uterine malignancies, and potential malignancies at the time of hysterectomy or myomectomy using power morcellation. METHODS: We performed a retrospective cohort study of all women undergoing myomectomy or hysterectomy using power morcellation at 2 institutions between January 1, 2004, and May 31, 2015. The primary outcome was the incidence of uterine malignancy (UM). The predefined secondary outcome was the occurrence of other conditions associated with malignant behavior. For analysis, any UtSarc or endometrial cancer was categorized as a "uterine malignancy," whereas other pathologies with cytologic atypia were categorized as "uterine premalignant disease" (UPM). All other pathological results were classified as "nonmalignant." RESULTS: A total of 1004 women underwent hysterectomy or myomectomy using power morcellation during the studied period. Two women (1/502; 95% confidence interval [CI], 1/4144-1/139) were found to have UM pathology, 2 endometrial carcinomas and none with UtSarc (97.5% CI, 0-1/273). Six (1/167; 95% CI, 1/455-1/77) women were found to have UPM on final pathology: 2 atypical leiomyomas, 1 STUMP (smooth muscle tumors of uncertain malignant potential), and 3 endometrial atypical hyperplasias. Women with UM had uteri that weighed more than those with NM pathology (840 g vs 217.7 g, P = 0.028), and this trend was also seen with UM and UPM (435.0 g vs 217.2 g, P = 0.081). Women with UM and UPM were more likely to have a preoperative surgical indication of "uterine leiomyoma" compared with other benign etiologies (P < 0.001). CONCLUSIONS: Among this cohort, all cases of unsuspected UM at the time of myomectomy or hysterectomy using power morcellation were found to be endometrial carcinoma. Unsuspected UM pathology had an incidence of 1 of 502. Factors associated with increased likelihood of UM or UPM were greater uterine weight and leiomyoma as the surgical indication.

Society of Gynecologic Oncology recommendations for the prevention of ovarian cancer.

Mortality from ovarian cancer may be dramatically reduced with the implementation of attainable prevention strategies. The new understanding of the cells of origin and the molecular etiology of ovarian cancer warrants a strong recommendation to the public and health care providers. This document discusses potential prevention strategies, which include 1) oral contraceptive use, 2) tubal sterilization, 3) risk-reducing salpingo-oophorectomy in women at high hereditary risk of breast and ovarian cancer, 4) genetic counseling and testing for women with ovarian cancer and other high-risk families, and 5) salpingectomy after childbearing is complete (at the time of elective pelvic surgeries, at the time of hysterectomy, and as an alternative to tubal ligation). The Society of Gynecologic Oncology has determined that recent scientific breakthroughs warrant a new summary of the progress toward the prevention of ovarian cancer. This review is intended to emphasize the importance of the fallopian tubes as a potential source of high-grade serous cancer in women with and without known genetic mutations in addition to the use of oral contraceptive pills to reduce the risk of ovarian cancer.

Case report: Atypical, 'symplastic' leiomyoma recurring as leiomyosarcoma in the vagina.

•Leiomyosarcoma in the vagina is rare.•Atypical fibroids recurring as leiomyosarcoma•Leiomyomas should be classified based on recurrence risk.

Next-Gen Sequencing-Based Mapping and Identification of Ethyl Methanesulfonate-Induced Mutations in Arabidopsis thaliana.

Forward genetic analysis using ethyl methanesulfonate (EMS) mutagenesis has proven to be a powerful tool in biological research, but identification and cloning of causal mutations by conventional genetic mapping approaches is a painstaking process. Recent advances in next-gen sequencing have greatly invigorated the process of identifying EMS-induced mutations corresponding to a specific phenotype in model genetic hosts, including the plant Arabidopsis thaliana and the nematode Caenorhabditis elegans. Next-gen sequencing of bulked F2 mutant recombinants produces a wealth of high-resolution genetic data, provides enhanced delimitation of the genomic location of mutations, and greatly reduces hands-on time while maintaining high accuracy and reproducibility. In this unit, a detailed procedure to simultaneously map and identify EMS mutations in Arabidopsis is described.