Cytoplasmic SIRT1 promotes paclitaxel resistance in ovarian carcinoma through increased formation and survival of polyploid giant cancer cells

Therapeutic resistance is a notable cause of death in patients with ovarian carcinoma. Polyploid giant cancer cells (PGCCs), commonly arising in tumor tissues following chemotherapy, have recently been considered to contribute to drug resistance. As a type III deacetylase, Sirtuin1 (SIRT1) plays essential roles in the cell cycle, cellular senescence, and drug resistance. Accumulating evidence has suggested that alteration in its subcellular localization via nucleocytoplasmic shuttling is a critical process influencing the functions of SIRT1. However, the roles of SIRT1 subcellular localization in PGCC formation and subsequent senescence escape remain unclear. In this study, we compared the differences in the polyploid cell population and senescence state of PGCCs following paclitaxel treatment between tumor cells overexpressing wild-type SIRT1 (WT SIRT1) and those expressing nuclear localization sequence (NLS)-mutated SIRT1 (SIRT1NLSmt ). We investigated the involvement of cytoplasmic SIRT1 in biological processes and signaling pathways, including the cell cycle and cellular senescence, in ovarian carcinoma cells' response to paclitaxel treatment. We found that the SIRT1NLSmt tumor cell population contained more polyploid cells and fewer senescent PGCCs than the SIRT1-overexpressing tumor cell population. Comparative proteomic analyses using co-immunoprecipitation (Co-IP) combined with liquid chromatography-mass spectrometry (LC-MS)/MS showed the differences in the differentially expressed proteins related to PGCC formation, cell growth, and death, including CDK1 and CDK2, between SIRT1NLSmt and SIRT1 cells or PGCCs. Our results suggested that ovarian carcinoma cells utilize polyploidy formation as a survival mechanism during exposure to paclitaxel-based treatment via the effect of cytoplasmic SIRT1 on PGCC formation and survival, thereby boosting paclitaxel resistance. © 2023 The Pathological Society of Great Britain and Ireland.

The response and resistance to drugs in ovarian cancer cell lines in 2D monolayers and 3D spheroids

Ovarian cancer is the most common type of gynecologic cancer. One of the leading causes of high mortality is chemoresistance, developed primarily or during treatment. Different mechanisms of drug resistance appear at the cellular and cancer tissue organization levels. We examined the differences in response to the cytotoxic drugs CIS, MTX, DOX, VIN, PAC, and TOP using 2D (two-dimensional) and 3D (three-dimensional) culture methods. We tested the drug-sensitive ovarian cancer cell line W1 and established resistant cell lines to appropriate cytotoxic drugs. The following qualitative and quantitative methods were used to assess: 1) morphology - inverted microscope and hematoxylin & eosin staining; 2) viability - MTT assay; 3) gene expression - a quantitative polymerase chain reaction; 4) identification of proteins - immunohistochemistry, and immunofluorescence. Our results indicate that the drug-sensitive and drug-resistant cells cultured in 3D conditions exhibit stronger resistance than the cells cultured in 2D conditions. A traditional 2D model shows that drug resistance of cancer cells is caused mainly by changes in the expression of genes encoding ATP-binding cassette transporter proteins, components of the extracellular matrix, "new" established genes related to drug resistance in ovarian cancer cell lines, and universal marker of cancer stem cells. Whereas in a 3D model, the drug resistance in spheroids can be related to other mechanisms such as the structure of the spheroid (dense or loose), the cell type (necrotic, quiescent, proliferating cells), drug concentrations or drug diffusion into the dense cellular/ECM structure.

SOX6 Expression Is Sensitive for Peritoneal Epithelioid Malignant Mesothelioma, But Not Specific in the Differential Diagnosis With Tubo-ovarian Serous Neoplasia

Primary peritoneal malignant mesothelioma (MM) can demonstrate morphologic overlap with low-grade and high-grade tubo-ovarian serous neoplasms; it is also biologically and prognostically distinct from benign mesothelial proliferations. Currently, there is no single biomarker that can definitively distinguish these neoplasms. Sex-determining region Y box 6 (SOX6) immunohistochemistry has been recently described to differentiate pleural epithelioid MM from lung adenocarcinoma, but it has not been evaluated in the peritoneum. SOX6 immunohistochemistry was performed on 43 peritoneal epithelioid MM, 7 peritoneal biphasic MM, 5 well-differentiated papillary mesotheliomas, 5 serous borderline tumors, 29 low-grade serous carcinomas (LGSCs), 20 high-grade serous carcinomas (HGSCs), and 25 cases of peritoneal reactive mesothelial hyperplasia. Quantitative SOX6 expression in epithelioid MM (median, 100% of tumor cells) was significantly greater than in LGSC/serous borderline tumor (median, 90%; P=0.004) and HGSC (median, 45%; P=0.0001). However, when SOX6 is expression is defined as ≥10% of tumor cells, there was no significant difference in the rate of SOX6 positivity between epithelioid MM (41/43, 95%), LGSC (28/29, 97%; P=1.0), and HGSC (17/20, 85%; P=0.16). Quantitative extent of SOX6 expression in epithelioid MM was significantly greater than in biphasic MM (median, 0%; P=0.0001), well-differentiated papillary mesothelioma (median, 20%; P=0.001), and reactive mesothelial hyperplasia (median, 20%; P=0.0001), but not significantly different from flat quiescent mesothelium (median, 90%; P=0.82). SOX6 immunohistochemistry is 95% sensitive for peritoneal epithelioid MM, but is also consistently expressed in LGSC and HGSC, negating its usefulness in this common differential diagnosis. SOX6 also shows variable expression across the spectrum of reactive, benign neoplastic, and malignant mesothelial lesions of the peritoneum, and does not appear to be diagnostically useful in distinguishing benign from malignant mesothelial proliferations.

Accurate Distinction of Ovarian Clear Cell From Endometrioid Carcinoma Requires Integration of Phenotype, Immunohistochemical Predictions, and Genotype: Implications for Lynch Syndrome Screening

Ovarian clear cell carcinoma (OCCC) and ovarian endometrioid carcinoma (OEC) are both associated with endometriosis but differ in histologic phenotype, biomarker profile, and survival. Our objectives were to refine immunohistochemical (IHC) panels that help distinguish the histotypes and reassess the prevalence of mismatch repair deficiency (MMRd) in immunohistochemically confirmed OCCC. We selected 8 candidate IHC markers to develop first-line and second-line panels in a training set of 344 OCCC/OEC cases. Interobserver reproducibility of histotype diagnosis was assessed in an independent testing cohort of 100 OCC/OEC initially without and subsequently with IHC. The prevalence of MMRd was evaluated using the testing cohort and an expansion set of 844 ovarian carcinomas. The 2 prototypical combinations (OCCC: Napsin A+/HNF1B diffusely+/PR-; OEC: Napsin A-/HNF1B nondiffuse/PR+) occurred in 75% of cases and were 100% specific. A second-line panel (ELAPOR1, AMACR, CDX2) predicted the remaining cases with 83% accuracy. Integration of IHC improved interobserver reproducibility (κ=0.778 vs. 0.882, P<0.0001). The prevalence of MMRd was highest in OEC (11.5%, 44/383), lower in OCCC (1.7%, 5/297), and high-grade serous carcinomas (0.7%, 5/699), and absent in mucinous (0/126) and low-grade serous carcinomas (0/50). All 5 MMRd OCCC were probable Lynch syndrome cases with prototypical IHC profile but ambiguous morphologic features: 3/5 with microcystic architecture and 2/5 with intratumoral stromal inflammation. Integration of first-line and second-line IHC panels increases diagnostic precision and enhances prognostication and triaging for predisposing/predictive molecular biomarker testing. Our data support universal Lynch syndrome screening in all patients with OEC when the diagnosis of other histotypes has been vigorously excluded.

STING pathway expression in low-grade serous carcinoma of the ovary: an unexpected therapeutic opportunity?

Ovarian carcinoma histotypes are distinct diseases with variable clinical outcomes and response to treatment. There is a need for new subtype-specific treatment modalities, especially for women with widespread and chemo-resistant disease. Stimulator of interferon genes (STING) is a part of the cGAS-STING pathway that mediates innate immune defence against infectious DNA-containing pathogens and also detects tumour-derived DNA and generates intrinsic antitumour immunity. The STING signalling pathway is suppressed by several mechanisms in a variety of malignant diseases and, in some cancers that may be a requirement for cellular transformation. The aim of this study was to use immunohistochemistry to evaluate STING protein expression across normal tissue, paratubal and ovarian cysts, and ovarian tumour histotypes including ovarian carcinomas. Herein, we show that the fallopian tube ciliated cells express STING protein, whereas the secretory cells are negative. STING expression differs among ovarian cancer histotypes; low-grade serous ovarian carcinomas and serous borderline tumours have uniform high STING expression, while high-grade serous and endometrioid carcinomas have heterogeneous expression, and clear cell and mucinous carcinomas show low expression. As low-grade serous carcinomas are known to be genomically stable and typically lack a prominent host immune response, the consistently high STING expression is unexpected. High STING expression may reflect pathway activation or histogenesis and the mechanisms may be different in different ovarian carcinoma histotypes. Further studies are needed to determine whether the STING signalling pathway is active and whether these tumours would be candidates for therapeutic interventions that trigger innate immunity activation.

Robust sequential biophysical fractionation of blood plasma to study variations in the biomolecular landscape of systemically circulating extracellular vesicles across clinical conditions

Separating extracellular vesicles (EV) from blood plasma is challenging and complicates their biological understanding and biomarker development. In this study, we fractionate blood plasma by combining size-exclusion chromatography (SEC) and OptiPrep density gradient centrifugation to study clinical context-dependent and time-dependent variations in the biomolecular landscape of systemically circulating EV. Using pooled blood plasma samples from breast cancer patients, we first demonstrate the technical repeatability of blood plasma fractionation. Using serial blood plasma samples from HIV and ovarian cancer patients (n = 10) we next show that EV carry a clinical context-dependent and/or time-dependent protein and small RNA composition, including miRNA and tRNA. In addition, differential analysis of blood plasma fractions provides a catalogue of putative proteins not associated with systemically circulating EV. In conclusion, the implementation of blood plasma fractionation allows to advance the biological understanding and biomarker development of systemically circulating EV.

Clinicopathologic Characteristics of Mesonephric Adenocarcinomas and Mesonephric-like Adenocarcinomas in the Gynecologic Tract: A Multi-institutional Study

Mesonephric adenocarcinoma (MA) and mesonephric-like adenocarcinoma (MLA) are uncommon neoplasms of the gynecologic tract that have until recently been poorly understood. Although their morphologic, immunohistochemical, and molecular profiles have been recently defined, little is known about their clinical behavior. Small studies have demonstrated inconsistent findings and no large studies have examined the clinical behavior of these adenocarcinomas. In this multi-institutional study, representing the largest and most stringently defined cohort of cases to date, we examined the clinicopathologic features of 99 MAs and MLAs (30 MAs of the uterine cervix, 44 MLAs of the endometrium, and 25 MLAs of the ovary). Only tumors with characteristic mesonephric morphology and either immunohistochemical or molecular support were included. Our results demonstrate that the majority of mesonephric neoplasms presented at an advanced stage (II to IV) (15/25 [60%] MA of the cervix, 25/43 [58%] MLA of the endometrium, and 7/18 [39%] MLA of the ovary). The majority (46/89 [52%] overall, 12/24 [50%] MA of the cervix, 24/41 [59%] MLA of the endometrium, and 10/24 [42%] MLA of the ovary) developed recurrences, most commonly distant (9/12 [75%] MA of the cervix, 22/24 [92%] MLA of the endometrium, and 5/9 [56%] MLA of the ovary). The 5-year disease-specific survival was 74% (n=26) for MA of cervix, 72% (n=43) for MLA of endometrium, and 71% (n=23) for MLA of ovary. Our results confirm that mesonephric neoplasms are a clinically aggressive group of gynecologic carcinomas that typically present at an advanced stage, with a predilection for pulmonary recurrence.

Liquid Biopsies in the Clinical Management of Germ Cell Tumor Patients: State-of-the-Art and Future Directions

Liquid biopsies constitute a minimally invasive means of managing cancer patients, entailing early diagnosis, follow-up and prediction of response to therapy. Their use in the germ cell tumor field is invaluable since diagnostic tissue biopsies (which are invasive) are often not performed, and therefore only a presumptive diagnosis can be made, confirmed upon examination of the surgical specimen. Herein, we provide an overall review of the current liquid biopsy-based biomarkers of this disease, including the classical, routinely used serum tumor markers—the promising microRNAs rapidly approaching the introduction into clinical practice—but also cell-free DNA markers (including DNA methylation) and circulating tumor cells. Finally, and importantly, we also explore novel strategies and challenges for liquid biopsy markers and methodologies, providing a critical view of the future directions for liquid biopsy tests in this field, highlighting gaps and unanswered questions.

Quantitative laser-induced breakdown spectroscopy for discriminating neoplastic tissues from non-neoplastic ones

In this paper, we present a method to distinguish neoplastic tissues from non-neoplastic ones using calibration-free laser-induced breakdown spectroscopy (CF-LIBS). For this propose, plasma emission was collected from neoplastic and non-neoplastic tissues taken from the ovarian cancer mice models. Results were obtained by utilizing the characteristic plasma emission lines of different elements that have been confirmed in the investigated samples. From the temporal evolution of plasma emission, the optimum temporal-observation-windows are identified for LIBS investigation. The concentrations of the detected elements in tissues were measured by a calibration-free approach based on data process of plasma parameters at the local thermodynamic equilibrium. The neoplastic specimens provided more energetic plasma than non-neoplastic ones that resulting in higher peaks intensities, electron density and electron temperature especially in the early windows (between 0.1 µs to 0.8 µs). Results demonstrated higher concentrations of major and trace elements such as Mg, Fe, Ca, Na, and K in the neoplastic tissues. Finally, the results using CF-LIBS method were found to be in good agreement with that of Inductive coupled plasma-optical emission spectroscopy (ICP-OES).

Tuning Nanoparticle Interactions with Ovarian Cancer through Layer-by-Layer Modification of Surface Chemistry

Nanoparticle surface chemistry is a fundamental engineering parameter that governs tumor-targeting activity. Electrostatic assembly generates controlled polyelectrolyte complexes through the process of adsorption and charge overcompensation utilizing synthetic polyions and natural biomacromolecules; it can yield films with distinctive hydration, charge, and presentation of functional groups. Here, we used electrostatic layer-by-layer (LbL) assembly to screen 10 different surface chemistries for their ability to preferentially target human ovarian cancer in vitro. Our screen identified that poly-l-aspartate, poly-l-glutamate, and hyaluronate-coated LbL nanoparticles have striking specificity for ovarian cancer, while sulfated poly(β-cyclodextrin) nanoparticles target noncancerous stromal cells. We validated top candidates for tumor-homing ability with a murine model of metastatic disease and with patient-derived ovarian cancer spheroids. Nanoparticle surface chemistry also influenced subcellular trafficking, indicating strategies to target the cell membrane, caveolae, and perinuclear vesicles. Our results confirm LbL is a powerful tool to systematically engineer nanoparticles and achieve specific targeting.

Spatially Controlled Molecular Analysis of Biological Samples Using Nanodroplet Arrays and Direct Droplet Aspiration

Mass spectrometry (MS) has emerged as a valuable technology for molecular and spatial evaluation of biological samples. Ambient ionization MS techniques, in particular, allow direct analysis of tissue samples with minimal pretreatment. Here, we describe the design and optimization of an alternative ambient liquid extraction MS approach for metabolite and lipid profiling and imaging from biological samples. The system combines a piezoelectric picoliter dispenser to form solvent nanodroplets onto the sample surface with controlled and tunable spatial resolution and a conductive capillary to directly aspirate/ionize the nanodroplets for efficient analyte transmission and detection. Using this approach, we performed spatial profiling of mouse brain tissue sections with different droplet sizes (390, 420, and 500 μm). MS analysis of normal and cancerous human brain and ovarian tissues yielded rich metabolic profiles that were characteristic of disease state and enabled visualization of tissue regions with different histologic composition. This method was also used to analyze the lipid profiles of human ovarian cell lines. Overall, our results demonstrate the capabilities of this system for spatially controlled MS analysis of biological samples.

High glypican-3 expression characterizes a distinct subset of ovarian clear cell carcinomas in Canadian patients: an opportunity for targeted therapy

The expression frequency and distribution of glypican-3 (GPC3) was retrospectively assessed by immunohistochemistry in 316 accurately phenotyped ovarian clear cell carcinoma (OCCC) specimens from Canadian patients. The study aimed to evaluate the prevalence of this biomarker in OCCC in a mixed-ethnicity Canadian population and to evaluate associations of GPC3 expression with clinicopathological parameters. Tissue microarrays with napsin A or HNF1β positive and WT1-negative OCCC specimens were evaluated using a GPC3 antibody clone 1G12. Membranous, cytoplasmic, and Golgi pattern GPC3 expression was noted in 184 of 316 (58.2%) cases; 63 of 316 (20%) cases showed high GPC3 expression (>50% of tumor cells were positive). GPC3 expression was not associated with age, stage, and residual disease after primary surgery. High GPC3 expression did not correlate with a specific morphological pattern or the presence of endometriosis. Furthermore, GPC3 expression was not significantly associated with survival in the entire cohort. Statistically significant association of high GPC3 expression was noted with higher body mass index, napsin A positivity, estrogen receptor (ER) negativity, and ARID1A retention. In a stratified analysis by ARID1A status, high GPC3 expression was significantly associated with unfavorable outcomes in cases with loss of ARID1A (n=10; log rank p=0.0048). Women diagnosed with OCCC and high GPC3 expression were also more likely to receive adjuvant chemotherapy. Considering the tumor-specific membranous expression of GPC3 in 58% of cases and high interobserver reproducibility, GPC3 immunohistochemistry is a robust predictive test for inclusion in clinical trials for GPC3-targeted therapies for OCCC.

SFRP1 inhibited the epithelial ovarian cancer through inhibiting Wnt/β-catenin signaling

BACKGROUND

Epithelial ovarian cancer is the most malignant gynecologic neoplasm accounting for 90% of the ovarian cancer patients.

OBJECTIVE

Researchers proved that epigenetic alterations could disrupt gene expression as often as genetic alterations. Secreted frizzed related protein (SFRP1), a Wnt antagonist, exerts a significant effect on ovarian cancer. The aim of this research was to investigate the effects and the mechanism of action of SFRP1 on epithelial ovarian cancer.

METHODS

Clinical specimens (including fallopian tubes epithelium from 60 epithelial ovarian cancer patients' and 20 healthy subjects who were undergoing surgical treatments), transgenic mice (overexpressing SFRP1 gene), and 4 epithelial ovarian cancer cell lines (including OVCAR4, SKOV3, COV644, TOV21G) were used in this study. Overexpression of SFRP1 in cells was carried out on OVCAR4 cells by transfection using Lipofectamine 2000. Gene transcription was analyzed by qRT-PCR. The methylation of SFRP1 gene was quantified by methylation-specific PCR. The level of protein expression was measured by Western blot or immunohistochemistry analysis. Cell proliferation was analyzed by CCK8 methods. The ability of cell migration and invasion were measured by wound healing assay and transwell assay.

RESULTS

Abnormal expression level and hypermethylation status of SFRP1 were found in clinical epithelial ovarian cancer samples and cell lines. We observed that SFRP1 knockdown could promote proliferation, migration and invasion abilities of epithelial ovarian cancer cells. Additionally, we discovered a potential inhibitory effect of SFRP1 on Wnt/β-catenin signaling pathway in epithelial ovarian cancer cells. Furthermore, the anti-tumor effect of SFRP1 was tested in SFRP1 transgenic mice.

CONCLUSION

SFRP1 inhibited epithelial ovarian cancer through inhibiting Wnt/β-catenin pathway, suggesting that SFRP1 could be considered as a potential therapeutic target in epithelial ovarian cancer.

Fabrication of gold-silver core-shell nanoparticles for performing as ultrabright SERS-nanotags inside human ovarian cancer cells

This paper presents the fabrication and characterization of new gold-silver core-shell nanoparticles labeled with para-mercaptobenzoic acid (4MBA) molecules and demonstrates their use as surface-enhanced Raman spectroscopy (SERS)-nanotags with ultra-bright traceability inside cells and ability to convey spectrally-coded information about the intracellular pH by means of SERS. Unlike previous reported studies, our fabrication procedure includes in the first step the synthesis of chitosan-coated gold nanoparticles as a seed material with subsequent growing of a silver shell. The bimetallic core-shell structure is revealed by transmission electron microscopy, high-angle annular dark field scanning transmission electron microscopy, energy-dispersive x-ray elemental mapping and the presence of two interacting localized surface plasmon resonance modes in UV-vis extinction spectrum. The high SERS activity and sensitivity of as fabricated 4MBA-chit-Au-AgNPs nano-constructs to different pH in solution is investigated under 532 and 633 nm laser lines excitation. Next, in view of future studies in cancer diagnosis, the in vitro antiproliferative effects of SERS-nanotags against human ovarian adenocarcinoma cells (NIH:OVCAR-3) are evaluated. The capacity to operate as bright SERS nanotags with precise localization at a single cell level as well as intracellular pH indicators is clearly demonstrated by performing cell imaging under scanning confocal Raman microscopy.

MORPHOPHENOTYPIC CHARACTERISTICS OF OVARIAN SEROUS BORDERLINE TUMORS

Borderline ovarian tumors (BOTs) represent particular challenge for diagnosis and clinical management as they are characterized with the features of both benign cystadenomas and malignant carcinomas. The aim of our study was to investigate histomorphological and immunohistochemical characteristics of ovarian serous-papillary borderline tumors, compared to serous cystadenomas and low- and high-grade serous carcinomas. Altogether, 80 formalin fixed and paraffin embedded tissue specimens, distributed in four groups, including serous cystadenoma (group I), serous BOTs (group II), Low (group III) and high (group IV) grade serous carcinomas, were investigated by standard immunohistochemistry, using antibodies against CK7 CK20, WT1, Vimentin, CDX2, CEA, ER, cyclin D1, BCL2, E-cadherin, calretinin, СA125, Ki67, P53. Study results showed, that ovarian serous BOTs are characterized with slightly increase proliferative potential compared to benign cystadenomas, whilst apoptotic potential is retained with the difference from malignant serous carcinomas. p53 mutation is not present, as well as the expression of Vimentin. Overall, ovarian serous BOTs are characterized with highly variable immunohistochemical phenotype and the use of multiple immunohistochemical markers are recommended for the differential diagnosis from low grade serous carcinomas and benign cystadenomas.

Discriminating normal regions within cancerous hen ovarian tissue using multivariate hyperspectral image analysis

RATIONALE

Identification of subregions under different pathological conditions on cancerous tissue is of great significance for understanding cancer progression and metastasis. Infrared matrix-assisted laser desorption electrospray ionization mass spectrometry (IR-MALDESI-MS) can be potentially used for diagnostic purposes since it can monitor spatial distribution and abundance of metabolites and lipids in biological tissues. However, the large size and high dimensionality of hyperspectral data make analysis and interpretation challenging. To overcome these barriers, multivariate methods were applied to IR-MALDESI data for the first time, aiming at efficiently resolving mass spectral images, from which these results were then used to identify normal regions within cancerous tissue.

METHODS

Molecular profiles of healthy and cancerous hen ovary tissues were generated by IR-MALDESI-MS. Principal component analysis (PCA) combined with color-coding built a single tissue image which summarizes the high-dimensional data features. Pixels with similar color indicated similar composition. PCA results from healthy tissue were further used to test each pixel in cancerous tissue to determine if it is healthy. Multivariate curve resolution-alternating least squares (MCR-ALS) was used to obtain major spatial features existing in ovary tissues, and group molecules with the same distribution patterns simultaneously.

RESULTS

PCA as the predominating dimensionality reduction approach captured over 90% spectral variances by the first three PCs. The PCA images show the cancerous tissue is more chemically heterogeneous than healthy tissue, where at least four regions with different m/z profiles can be differentiated. PCA modeling assigns top regions of cancerous tissue as healthy-like. MCR-ALS extracted three and four major compounds from healthy and cancerous tissue, respectively. Evaluating similarities of resolved spectra uncovered the chemical components that were distinct in some regions on cancerous tissue, serving as a supplementary way to differentiate healthy and cancerous regions.

CONCLUSIONS

Two unsupervised chemometric methods including PCA and MCR-ALS were applied for resolving and visualizing IR-MALDESI-MS data acquired from hen ovary tissues, improving the interpretation of mass spectrometry imaging results. Then possible normal regions were differentiated from cancerous tissue sections. No prior knowledge is required using either chemometric method, so our approach is readily suitable for unstained tissue samples, which allows one to reveal the molecular events happening during disease progression.

Mass spectrometric discrimination of phospholipid patterns in cisplatin-resistant and -sensitive cancer cells

RATIONALE

Development of therapy-resistant cancer is a major problem in clinical oncology, and there is an urgent need for novel markers identifying development of the resistant phenotype. Lipidomics represents a promising approach to discriminate lipid profiles of malignant phenotype cells. Alterations in phospholipid distribution or chemical composition have been reported in various pathologies including cancer. Here we were curious whether quantitative differences in phospholipid composition between cisplatin-resistant and -sensitive model cancer cell lines could be revealed by mass spectrometric means.

METHODS

The phospholipid contents of cell membranes of the cancer cell lines CCRF-CEM and A2780, both responsive and resistant to cisplatin, were analyzed by solid-phase extraction (SPE) and electrospray ionization mass spectrometry (ESI-MS and tandem mass spectrometry (MS/MS)). Extracts were obtained by disruption of cells with a dounce tissue grinder set followed by centrifugation. To minimize the enzymatic activity, phospholipids were extracted from cell extracts by SPE immediately after the cell lysis and analyzed by MS. Both supernatant and pellet fractions of cell extracts were analyzed.

RESULTS

A phospholipid profile specific for cell lines and their phenotypes was revealed. We have documented by quantitative analysis that phosphocholines PC P-34:0, PC 34:1, PC 20:2_16:0, LPC 18:1 and LPC 16:0 PLs were present in the 200-400 μM concentration range in CCRF-CEM cisplatin-responsive cells, but absent in their cisplatin-resistant cells. Similarly, PC 34:1, LPC 18:1 and LPC 16:0 were increased in cisplatin-responsive A2780 cells, and PC 20:2_16:0 was downregulated in cisplatin-resistant A2780 cells.

CONCLUSIONS

In this work we showed that the ESI-MS analysis of the lipid content of the therapy-resistant and -sensitive cells can clearly distinguish the phenotypic pattern and determine the potential tumor response to cytotoxic therapy. Lipid entities revealed by mass spectrometry and associated with development of therapy resistance can thus support molecular diagnosis and provide a potential complementary cancer biomarker.

Checkpoint-inhibition in ovarian cancer: rising star or just a dream?

The introduction of checkpoint inhibitors revolutionized immuno-oncology. The efficacy of traditional immunotherapeutics, like vaccines and immunostimulants was very limited due to persistent immune-escape strategies of cancer cells. Checkpoint inhibitors target these escape mechanisms and re-direct the immune system to anti-tumor toxicity. Phenomenal results have been reported in entities like melanoma, where no other therapy was able to demonstrate survival benefit, before the introduction of immunotherapeutics. The first experience in ovarian cancer (OC) was reported for nivolumab, a fully human anti-programmed cell death protein 1 (PD1) antibody, in 2015. While the data are extraordinary for a mono-immunotherapeutic agent and very promising, they do not match up to the revolutionary results in entities like melanoma. The key to exceptional treatment response in OC, could be the identification of the most immunogenic patients. We hypothyse that BRCA mutation could be a predictor of improved response in OC. The underlying DNA-repair-deficiancy should result in increased immunogenicity because of higher mutational load and more neoantigen presentation. This hypothesis was not tested to date and should be subject to future trials. The present article gives an overview of the immunologic background of checkpoint inhibition (CI). It presents current data on nivolumab and other checkpoint-inhibitors in solid tumors and OC specifically and depicts important topics in the management of this novel substance group, such as side effect control, diagnostic PD-1/programmed cell death-ligand 1 (PD-L1) expression assessment and management of pseudoprogression.

HtrA1 expression and the prognosis of high-grade serous ovarian carcinoma: a cohort study using digital analysis

BACKGROUND

The expression of high temperature requirement factor A1 (Htra1) has been reported to be decreased in ovarian carcinoma, but its prognostic effect remains undetermined.

METHODS

We evaluated the impact of HtrA1 downregulation in tumoral tissues on cancer progression and death in women with serous ovarian carcinoma. HtrA1 staining was performed on tissue microarrays (TMA) comprised of tumor samples from a cohort of 106 women who were diagnosed with primary high-grade serous ovarian carcinoma and receiving standard treatment at the Québec University Hospital between 1993 and 2006. HtrA1 expression was assessed visually (percentage of positive nuclei) and by digital image analysis (percentage of positive area). Cox regression multivariate models included standard prognostic factors and were used to estimate adjusted hazard ratios (aHR) for progression or death in the cohort.

RESULTS

By visual analysis, a low percentage of HtrA1-positive nuclei (< 10% vs ≥10%) tend to be associated with a lower risk of progression (aHR = 0.71; 95% Confidence interval (CI) = 0.46-1.09; P = 0.11) and mortality (aHR = 0.65; 95% CI = 0.41-1.04; P = 0.07). Low nuclear HtrA1 expression assessed by digital image analysis (< median % vs ≥ median %) showed a significant association with lower risk of progression (aHR = 0.62; 95% CI = 0.40-0.95; p = 0.03) and death (aHR = 0.60; 95% CI = 0.38-0.95; p = 0.03).

CONCLUSION

Altogether, our results demonstrate that nuclear downregulation of HtrA1 is associated with a better prognosis in women with high grade serous ovarian carcinoma.

Differential Tumor Microenvironment in Human Ovarian Cystic Tumors

Aims and Background

Cells and soluble mediators obtained from tumor effusions are useful in evaluating the tumor microenvironment. Our aim was to examine cytologically and to quantify the leukocyte infiltrate, nitric oxide, cytokines and tumor markers in the intracystic fluid from patients with a cystic adnexal mass, for a possible differentiation between benign and malignant findings.

Methods and Study Design

Sixty-six women who had their cystic fluids collected were prospectively divided into benign tumor (22, 33.3%), malignant tumor (10, 15.2%) or other gynecological alterations (34, 51.5%). Cytology, total and differential leukocyte counts were determined by light microscopy. Tumor markers, cytokines and nitric oxide were assayed in the supernatants using the Immutile system, ELISA and Griess reaction, respectively.

Results

The sensitivity and specificity of the cytological analysis was 66.7% and 97.7%, respectively. The levels of CA 19.9, CA 15.3, α-fetoprotein, carcinoembryonic antigen, progesterone and β-HCG were significantly higher in the benign and/or malignant group than in the other gynecological alterations. Also, the local concentrations of CA 15.3 and β-HCG were significantly higher in malignant than in benign tumors. In malignant tumors, increased leukocyte counts and higher concentrations of IL-6, IL-10 and nitric oxide were detected than in benign tumors or other gynecological alterations.

Conclusions

In malignant tumors, the microenvironment could be differentiated from benign tumors or other gynecological alterations by cystic fluid analysis.

P53 Expression, Dna Ploidy and Mitotic Index as Prognostic Factors in Patients with Epithelial Ovarian Carcinoma

Aims and Background

Biological variables linked to genomic instability were examined and related to survival in 52 patients affected by ovarian carcinoma and nine patients with low malignant potential tumors (LMP).

Methods

DNA ploidy was measured by image cytometry in isolated neoplastic cells; the mitotic index was measured in Feulgen-toluidine blue-stained sections and p53 was investigated by immunohistochemistry.

Results

Twenty-five tumors (4 LMP) were peridiploid (ploidy <2.25c), 22 tumors (4 LMP) were hyperdiploid (2.25c>ploidy<2.9c) and 14 (1 LMP) had high ploidy (≥2.9c). Ml ranged from 0.3 to 24.2 with a mean of 1.8 for LMP and 6.8 for carcinomas (P <0.001). Widespread p53 overexpression was detected in 49% of carcinomas and in none of the LMP tumors.

Conclusions

Survival analysis performed in patients with carcinomas indicated that, of the examined biological variables, only Ml was moderately associated with survival in a subgroup of early-stage patients.

Tissue Quantification of CA 125 in Epithelial Ovarian Cancer

The objectives of this study were the determination of CA 125 in the cytosol of healthy and carcinomatous ovarian tissue by immunoanalysis, analysis of its correlation with the biological characteristics of ovarian carcinoma, determination of serum CA 125 levels, and study of the prognostic value of the marker in cytosol. The levels of the marker depend not only on the tumor's production rate, so its determination in tissue can indicate more accurately if the tumor is a producer of the marker and establish its value for the prognosis of the disease. Determination of CA 125 in tissue was performed by immunoanalysis in 50 ovarian epithelial cancer samples, 13 benign pathology samples and 32 healthy ovary samples. The presurgical serum level of the marker was also obtained. The correlation between the CA 125 level in the cytosol and the different biological characteristics of the ovarian carcinoma, the serum levels of the marker and survival were analyzed. The CA 125 level proved to be higher in malignant tissue (p<0.0001). There was a significant association between the tissue marker and histological type (high CA 125 was associated with serous and endometrioid tumors) and between the marker and survival. No relation with stage was found. There was a correlation between the CA 125 level in the cytosol and serum, both variables being dependent, with a correlation coefficient of 0.44. This good correlation speaks in favor of the usefulness of CA 125 determination in serum in the follow-up of ovarian cancer. Tumors having high tissue expression of CA 125 were found to have a double relative risk of death, independently of tumor stage.

Chemical Analysis of Morphological Changes in Lysophosphatidic Acid-Treated Ovarian Cancer Cells

Ovarian cancer (OvCa) cells are reported to undergo biochemical changes at the cell surface in response to treatment with lysophosphatidic acid (LPA). Here we use scanning electron microscopy (SEM) and multiplex coherent anti-Stokes Raman scattering (CARS) imaging via supercontinuum excitation to probe morphological changes that result from LPA treatment. SEM images show distinct shedding of microvilli-like features upon treatment with LPA. Analysis of multiplex CARS images can distinguish between molecular components, such as lipids and proteins. Our results indicate that OvCa429 and SKOV3ip epithelial ovarian cancer cells undergo similar morphological and chemical responses to treatment with LPA. The microvilli-like structures on the surface of multicellular aggregates (MCAs) are removed by treatment with LPA. The CARS analysis shows a distinct decrease in protein and increase in lipid composition on the surface of LPA-treated cells. Importantly, the CARS signals from cellular sheddings from MCAs with LPA treatment are consistent with cleavage of proteins originally present. Mass spectrometry on the cellular sheddings show that a large number of proteins, both membrane and intracellular, are present. An increased number of peptides are detected for the mesenchymal cell line relative to the epithelial cell indicating a differential response to LPA treatment with cancer progression.

Characterization of the Extracellular Matrix of Normal and Diseased Tissues Using Proteomics

The extracellular matrix (ECM) is a complex meshwork of insoluble fibrillar proteins and signaling factors interacting together to provide architectural and instructional cues to the surrounding cells. Alterations in ECM organization or composition and excessive ECM deposition have been observed in diseases such as fibrosis, cardiovascular diseases, and cancer. We provide here optimized protocols to solubilize ECM proteins from normal or tumor tissues, digest the proteins into peptides, analyze ECM peptides by mass spectrometry, and interpret the mass spectrometric data. In addition, we present here two novel R-script-based web tools allowing rapid annotation and relative quantification of ECM proteins, peptides, and intensity/abundance in mass spectrometric data output files. We illustrate this protocol with ECMs obtained from two pairs of tissues, which differ in ECM content and cellularity: triple-negative breast cancer and adjacent mammary tissue, and omental metastasis from high-grade serous ovarian cancer and normal omentum. The complete proteomics data set generated in this study has been deposited to the public repository ProteomeXchange with the data set identifier: PXD005554.

Safety and Activity of Mirvetuximab Soravtansine (IMGN853), a Folate Receptor Alpha-Targeting Antibody-Drug Conjugate, in Platinum-Resistant Ovarian, Fallopian Tube, or Primary Peritoneal Cancer: A Phase I Expansion Study

Purpose This phase I expansion cohort study evaluated the safety and clinical activity of mirvetuximab soravtansine (IMGN853), an antibody-drug conjugate consisting of a humanized anti-folate receptor alpha (FRα) monoclonal antibody linked to the tubulin-disrupting maytansinoid DM4, in a population of patients with FRα-positive and platinum-resistant ovarian cancer. Patients and Methods Patients with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer received IMGN853 at 6.0 mg/kg (adjusted ideal body weight) once every 3 weeks. Eligibility included a minimum requirement of FRα positivity by immunohistochemistry (≥ 25% of tumor cells with at least 2+ staining intensity). Adverse events, tumor response (via Response Evaluation Criteria in Solid Tumors [RECIST] version 1.1), and progression-free survival (PFS) were determined. Results Forty-six patients were enrolled. Adverse events were generally mild (≤ grade 2), with diarrhea (44%), blurred vision (41%), nausea (37%), and fatigue (30%) being the most commonly observed treatment-related toxicities. Grade 3 fatigue and hypotension were reported in two patients each (4%). For all evaluable patients, the confirmed objective response rate was 26%, including one complete and 11 partial responses, and the median PFS was 4.8 months. The median duration of response was 19.1 weeks. Notably, in the subset of patients who had received three or fewer prior lines of therapy (n = 23), an objective response rate of 39%, PFS of 6.7 months, and duration of response of 19.6 weeks were observed. Conclusion IMGN853 exhibited a manageable safety profile and was active in platinum-resistant ovarian cancer, with the strongest signals of efficacy observed in less heavily pretreated individuals. On the basis of these findings, the dose, schedule, and target population were identified for a phase III trial of IMGN853 monotherapy in patients with platinum-resistant disease.

Cytological Findings of Ascitic Fluid with a Malignant Ovarian Steroid Cell Tumor: A Case Report and Literature Review

BACKGROUND

Ovarian steroid cell tumors (SCTs) are rare and usually benign, although 25-43% are reportedly malignant. The cytologic findings of these rare ovarian tumors have almost never been reported.

CASE

We report a rare case of a malignant ovarian SCT with peritoneal dissemination and malignant ascites in a 40-year-old woman. Her tumor was classified as stage IIB (pT2bNoM0) according to the FIGO (International Federation of Gynecology and Obstetrics) classification system, and she was treated with adjuvant chemotherapy following staging laparotomy. Cytology of the ascitic fluid revealed large, polygonal-to-round cells and multinucleated cells with atypia, appearing in clusters with slight overlapping or as isolated tumor cells. Numerous tumor cells had small central round or eccentric nuclei with conspicuous nucleoli, and a moderate-to-abundant amount of cytoplasm, varying from granular and eosinophilic to pale and multivacuolated (foamy), with cannibalism formations. The nuclear chromatin was fine and granular, with irregular distribution and nuclear-membrane thickening.

CONCLUSION

These may be the first reported cytology results for ascites with a malignant SCT. Our patient's cytological ascitic findings, rather than the histopathologic features of the original and disseminated tumors, represent the malignant features of the tumor.

Development of Cell-Permeable, Non-Helical Constrained Peptides to Target a Key Protein-Protein Interaction in Ovarian Cancer

There is a lack of current treatment options for ovarian clear cell carcinoma (CCC) and the cancer is often resistant to platinum-based chemotherapy. Hence there is an urgent need for novel therapeutics. The transcription factor hepatocyte nuclear factor 1β (HNF1β) is ubiquitously overexpressed in CCC and is seen as an attractive therapeutic target. This was validated through shRNA-mediated knockdown of the target protein, HNF1β, in five high- and low-HNF1β-expressing CCC lines. To inhibit the protein function, cell-permeable, non-helical constrained proteomimetics to target the HNF1β-importin α protein-protein interaction were designed, guided by X-ray crystallographic data and molecular dynamics simulations. In this way, we developed the first reported series of constrained peptide nuclear import inhibitors. Importantly, this general approach may be extended to other transcription factors.

Prognostic value of cyclin E expression in patients with ovarian cancer: a Meta-analysis

PURPOSE

Cell cycle is mainly mediated by cyclins, cyclin- dependent kinases (CDK), and CDK inhibitors. Cyclin E is the main regulator for transition from G1 to S phase, and is involved in cancer pathogenesis, progression and metastasis. Nevertheless, there is still a controversy of the prognostic value of cyclin E overexpression in ovarian cancer patients. This meta-analysis is the first study aimed at analyzing the effect of cyclin E overexpression on the prognosis of ovarian cancer.

METHODS

By systematically searching the PUBMED, EMBASE and MEDLINE databases for relevant articles with publication dates up to January 2016 and selection following inclusion and exclusion criteria, 8 studies with 1470 patients were enrolled in our meta-analysis. The overall survival (OS) of patients with cyclin E overexpression was calculated using hazard ratio (HR) with 95% confidence intervals (CIs). The studies were categorized according to the author and year, demographic data in each study, ovarian cancer related information, and cyclin E cut-off value.

RESULTS

Cyclin E overexpression in ovarian cancer was a poor prognostic factor with statistical significance for OS (HR=1.48, 95%CI: 1.12,1.85). Using confunnel, we found no publication bias in our analysis.

CONCLUSION

Cyclin E might be considered as a prognostic factor for ovarian cancer, as supported by our meta-analysis. However, more high-quality studies should be conducted to find better clinical use of cyclin E in ovarian cancer.

New biomarkers in epithelial ovarian cancer: needed or redundant?

OBJECTIVE

For many years, intensive research has been dedicated to the development of sensitive biomarkers to detect various malignant diseases, including for the differentiation between a benign or malignant ovarian mass. One of these biomarkers is human epididymal protein 4 (HE4), which has been shown to have a higher specificity than, and comparable sensitivity to CA 125. HE4 is included in some predictive models. These new models have not yet been widely implemented in standard clinical care. The authors investigated the perceived need for new biomarkers and prediction models among Dutch gynecologists.

MATERIALS AND METHODS

A web-based survey containing 38 questions was sent to all gynecologists (in training) registered by the Dutch Society of Obstetrics and Gynecology.

RESULTS

313 respondents completed the survey (23% response rate), of which 29% were specialized in or devoted at least part of their practice to oncology. Approximately two-thirds of the respondents indicated that there is a need for a new biomarker. Respondents indicated that they would use HE4 primarily as a diagnostic tool in the case of a pelvic mass (57%), followed by screening in case of risk factors (30%), detection of recurrent disease (23%), monitoring therapy response (22%), and as a prognostic factor (10%). Only 11% would not use HE4 at all.

CONCLUSION

Evaluating the need for new technologies and diagnostics, including biomarkers, is important to avoid expensive research with min- imal clinical implications. In general, there is a perceived need for a new biomarker, if it can be used to improve the accuracy of diagnosis in patients with a pelvic mass.

Ambient Ionization and FAIMS Mass Spectrometry for Enhanced Imaging of Multiply Charged Molecular Ions in Biological Tissues

Ambient ionization mass spectrometry imaging (MSI) has been increasingly used to investigate the molecular distribution of biological tissue samples. Here, we report the integration and optimization of desorption electrospray ionization (DESI) and liquid-microjunction surface sampling probe (LMJ-SSP) with a chip-based high-field asymmetric waveform ion mobility spectrometry (FAIMS) device to image metabolites, lipids, and proteins in biological tissue samples. Optimized FAIMS parameters for specific molecular classes enabled semitargeted detection of multiply charged molecular species at enhanced signal-to-noise ratios (S/N), improved visualization of spatial distributions, and, most importantly, allowed detection of species which were unseen by ambient ionization MSI alone. Under static DESI-FAIMS conditions selected for transmission of doubly charged cardiolipins (CL), for example, detection of 71 different CL species was achieved in rat brain, 23 of which were not observed by DESI alone. Diagnostic CL were imaged in a human thyroid tumor sample with reduced interference of isobaric species. LMJ-SSP-FAIMS enabled detection of 84 multiply charged protein ions in rat brain tissue, 66 of which were exclusive to this approach. Spatial visualization of proteins in substructures of rat brain, and in human ovarian cancerous, necrotic, and normal tissues was achieved. Our results indicate that integration of FAIMS with ambient ionization MS allows improved detection and imaging of selected molecular species. We show that this methodology is valuable in biomedical applications of MSI for detection of multiply charged lipids and proteins from biological tissues.

Characterizing optical properties and spatial heterogeneity of human ovarian tissue using spatial frequency domain imaging

A spatial frequency domain imaging (SFDI) system was developed for characterizing ex vivo human ovarian tissue using wide-field absorption and scattering properties and their spatial heterogeneities. Based on the observed differences between absorption and scattering images of different ovarian tissue groups, six parameters were quantitatively extracted. These are the mean absorption and scattering, spatial heterogeneities of both absorption and scattering maps measured by a standard deviation, and a fitting error of a Gaussian model fitted to normalized mean Radon transform of the absorption and scattering maps. A logistic regression model was used for classification of malignant and normal ovarian tissues. A sensitivity of 95%, specificity of 100%, and area under the curve of 0.98 were obtained using six parameters extracted from the SFDI images. The preliminary results demonstrate the diagnostic potential of the SFDI method for quantitative characterization of wide-field optical properties and the spatial distribution heterogeneity of human ovarian tissue. SFDI could be an extremely robust and valuable tool for evaluation of the ovary and detection of neoplastic changes of ovarian cancer.

A puzzling ovarian tumour: pregnancy luteoma with diffuse endometriosis

BACKGROUND

Pregnancy luteoma is a distinctive non-neoplastic hormone dependent lesion arising in pregnancy and mimicking an ovarian tumour. Fewer than 200 cases have been described in the English-language literature. Its clinical and morphological features are characteristic and must be considered in order to prevent diagnostic misinterpretation. To the best of our knowledge the association of pregnancy luteoma with endometriosis has not been reported in literature to date.

CASE REPORT

A 30-year-old pregnant woman with no particular past medical history, consulted her gynaecologist at 17 weeks gestation for routine check-up. The patient was asymptomatic and did not show any signs of virilization. Ultrasonography disclosed a left adnexal heterogeneous mass measuring 7 cm in diameter with intramural vegetations. The right ovary was unremarkable. The patient underwent salpingo-oophorectomy considering the imaging findings were suspicious for malignancy. Histologically, the lesion was constituted of large sheets of luteinized polygonal cells with abundant eosinophilic cytoplasm and small round nuclei devoid of atypia and mitotic figures. In addition, there were several ectopic endometrial glands surrounded by abundant decidualized or edematous stroma. Immunohistochemically, these glands were immunoreactive for cytokeratin 7. The final pathological diagnosis was pregnancy luteoma associated with diffuse endometriosis.

CONCLUSIONS

Because of its relative rarity, pregnancy luteoma is likely to be clinically misinterpreted and overtreated, as in the present case.

A metabolic labeling approach for glycoproteomic analysis reveals altered glycoprotein expression upon GALNT3 knockdown in ovarian cancer cells

Epithelial ovarian cancer (EOC) is a disease responsible for more deaths among women in the Western world than all other gynecologic malignancies. There is urgent need for new therapeutic targets and a better understanding of EOC initiation and progression. We have previously identified the polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3) gene, a member of the GalNAc-transferases (GalNAc-Ts) gene family, as hypomethylated and overexpressed in high-grade serous EOC tumors, compared to low malignant potential EOC tumors and normal ovarian tissues. This data also suggested for a role of GALNT3 in aberrant EOC glycosylation, possibly implicated in disease progression. To evaluate differential glycosylation in EOC caused by modulations in GALNT3 expression, we used a metabolic labeling strategy for enrichment and mass spectrometry-based characterization of glycoproteins following GALNT3 gene knockdown (KD) in A2780s EOC cells. A total of 589 differentially expressed glycoproteins were identified upon GALNT3 KD. Most identified proteins were involved in mechanisms of cellular metabolic functions, post-translational modifications, and some have been reported to be implicated in EOC etiology. The GALNT3-dependent glycoproteins identified by this metabolic labeling approach support the oncogenic role of GALNT3 in EOC dissemination and may be pursued as novel EOC biomarkers and/or therapeutic targets.

BIOLOGICAL SIGNIFICANCE

Knowledge of the O-glycoproteome has been relatively elusive, and the functions of the individual polypeptide GalNAc-Ts have been poorly characterized. Alterations in GalNAc-Ts expression were shown to provide huge variability in the O-glycoproteome in various pathologies, including cancer. The application of a chemical biology approach for the metabolic labeling and subsequent characterization of O-glycoproteins in EOC using the Ac4GalNAz metabolite has provided a strategy allowing for proteomic discovery of GalNAc-Ts specific functions. Our study supports an essential role of one of the GalNAc-Ts - GALNT3, in EOC dissemination, including its implication in modulating PTMs and EOC metabolism. Our approach validates the use of the applied metabolic strategy to identify important functions of GalNAc-Ts in normal and pathological conditions.

Panobinostat sensitizes cyclin E high, homologous recombination-proficient ovarian cancer to olaparib

OBJECTIVE

Homologous recombination (HR) proficient ovarian cancers, including CCNE1 (cyclin E)-amplified tumors, are resistant to poly (ADP-ribose) polymerase inhibitors (PARPi). Histone deacetylase inhibitors (HDACi) are effective in overcoming tumor resistance to DNA damaging drugs. Our goal was to determine whether panobinostat, a newly FDA-approved HDACi, can sensitize cyclin E, HR-proficient ovarian cancer cells to the PARPi olaparib.

METHODS

Expression levels of CCNE1 (cyclin E), BRCA1, RAD51 and E2F1 in ovarian tumors and cell lines were extracted from The Cancer Genome Atlas (TCGA) and Broad-Novartis Cancer Cell Line Encyclopedia (CCLE). In HR-proficient ovarian cancer cell line models (OVCAR-3, OVCAR-4, SKOV-3, and UWB1.289+BRCA1 wild-type), cell growth and viability were assessed by sulforhodamine B and xenograft assays. DNA damage and repair (pH2AX and RAD51 co-localization and DRGFP reporter activity) and apoptosis (cleaved PARP and cleaved caspase-3) were assessed by immunofluorescence and Western blot assays.

RESULTS

TCGA and CCLE data revealed positive correlations (Spearman) between cyclin E E2F1, and E2F1 gene targets related to DNA repair (BRCA1 and RAD51). Panobinostat downregulated cyclin E and HR repair pathway genes, and reduced HR efficiency in cyclin E-amplified OVCAR-3 cells. Further, panobinostat synergized with olaparib in reducing cell growth and viability in HR-proficient cells. Similar co-operative effects were observed in xenografts, and on pharmacodynamic markers of HR repair, DNA damage and apoptosis.

CONCLUSIONS

These results provide preclinical rationale for using HDACi to reduce HR in cyclin E-overexpressing and other types of HR-proficient ovarian cancer as a means of enhancing PARPi activity.

Primary ovarian fibrosarcoma: a case report and review of the literature

OBJECTIVES

Primary ovarian fibrosarcomas are extremely rare neoplasms, and only 50 cases have been reported in the English literature. Diagnosis can be difficult because of this condition's rarity, and other similar appearing mesenchymal lesions should be ruled out.

METHODS

A 50-year-old postmenopausal woman came to our hospital because of abdominopelvic pain. Ultrasonography revealed a 41x33 mm heterogeneous solid mass in the right ovary. Total blood counts, biochemical parameters, and tumor markers were within normal ranges. Total abdominal hysterectomy, and bilateral salpingo oophorectomy were performed. Examination of a frozen, specimen revealed fibroma; however, the final histopathological diagnosis was low grade fibrosarcoma of the ovary. Microscopic examination demonstrated densely cellular, spindle-shaped tumor cells with increased mitotic activity (5 to 6 mitoses per 10 high-power fields).

RESULTS

Immunohistochemical analysis revealed that the tumor cells were positive for vimentin and negative for actin and desmin and that the Ki 67 proliferation index was 30% to 40%. The patient did not receive adjuvant treatment, and remained free of disease after a follow up of 6 months.

CONCLUSIONS

Although ovarian fibrosarcomas are unusual causes of solid masses in postmenopausal women, they should be considered when adnexal masses are examined in these patients. Mitotic activity and Ki-67 positivity were identified as important diagnostic factors for ovarian fibrosarcoma.

Comparative Analysis of the Distribution of Laminin Chains in the Basement Membranes in Some Malignant Epithelial Tumors: The α1 Chain of Laminin Shows a Selected Expression Pattern in Human Carcinomas

Laminins (Ln), together with Type IV collagen and nidogen-1, form the structural integrity of the basement membranes (BM). In this study we used immunohistochemistry to show the distribution of laminin chains α1, α3, α5, β1, β2, β3, γ1, γ2, as well as Type IV collagen, in various types of carcinomas and in normal tissues. Except for diffuse gastric carcinomas and infiltrative breast carcinomas, the malignant epithelial tumor clusters were surrounded by quite a continuous BM in most tumors. These BMs comprised most abundantly Ln α5, β1, and γ1 chains. Conversely, the Ln α1 chain, a component of laminins-1 and -3, showed the most restricted distribution in BMs of both normal tissues and malignancies, being moderately present in carcinomas of thyroid gland and ovary and in intraductal carcinomas of breast. In other types of carcinomas, immunoreactivity for Ln α1 chain was found more randomly and was practically negative in carcinomas of tongue, stomach, and colon. These findings were comparable to those observed by in situ hybridization, which showed that carcinomas of thyroid gland and intraductal carcinomas of breast constitutively expressed Ln α1 mRNA and that the epithelial tumor cells were the main producers of it. The results suggest that epithelial malignancies, except for infiltrative breast and diffuse gastric carcinomas, produce more notable amounts of BM macromolecules in their growth substratum than has previously been anticipated. Corroborating their widespread distribution in normal epithelial tissues, the chains of Lns-5 and -10 are the most abundant Ln molecules in the corresponding carcinomas.

The associations between serum VEGF, bFGF and endoglin levels with microvessel density and expression of proangiogenic factors in malignant and benign ovarian tumors

AIM OF THE STUDY

To investigate whether serum levels of VEGF, bFGF and endoglin correlate with tumor VEGF and bFGF expression or microvessel density (MVD) in ovarian cancer.

PATIENTS AND METHODS

Forty five patients with epithelial ovarian cancers (EOCs) and 38 patients with benign ovarian tumors (BOTs) were included into the study. Serum levels of VEGF, bFGF and endoglin were assessed using ELISA. The expression of VEGF and bFGF in tumor samples were evaluated using ELISA of supernatants obtained from tumor homogenization. MVD was analyzed using immunohistochemistry with antibodies against CD31, CD34 and CD105.

RESULTS

Serum VEGF levels were significantly higher in EOCs than in BOTs (436.6pg/ml [19.67-2860] vs 295.5pg/ml [123-539], P=0.025). Serum endoglin levels were lowered in the group EOCs when compared to BOTs (33,720g/ml [12,220-73,940] vs 42,390pg/ml [19,380-56,910], P=0.015). There were no differences in bFGF levels between studied groups. EOCs have significantly higher CD105 MVD (25 vessels/mm2 [0-57] vs 6 vessels/mm2 [0-70], P<0.001) and tumor VEGF (405.9pg/mg protein [0-3000] vs 2.225 [0-634.7], P<0.001) expression than BOTs, while, bFGF expression was higher in BOTs than in EOCs (2076pg/mg protein [668.1-8718] vs 847.3pg/mg protein [188.9-8333], P=0.003). In patients with EOCs we have observed negative correlation between serum VEGF concentration and its tissue expression (r Spearman=-0.571, P=0.0261), and serum VEGF concentration correlated positively with CD34-MVD (r Spearman=0.545, P=0.0289). In a multiple regression analysis we have observed only the negative correlation between serum VEGF and CD105-MVD (r=-0.5288, P=0.0427).

CONCLUSIONS

Serum VEGF is a useful marker for prediction of ovarian cancer MVD and tumor VEGF expression.

Characterizing the Epothilone Binding Site on β-Tubulin by Photoaffinity Labeling: Identification of β-Tubulin Peptides TARGSQQY and TSRGSQQY as Targets of an Epothilone Photoprobe for Polymerized Tubulin

Photoaffinity labeling with an epothilone A photoprobe led to the identification of the β-tubulin peptides TARGSQQY and TSRGSQQY as targets of the photoprobe for polymerized tubulin. These peptides represent residues 274-281 in different β-tubulin isotypes. Placing the carbene producing 21-diazo/triazolo moiety of the photoprobe in the vicinity of the TARGSQQY peptide in a homology model of TBB3 predicted a binding pose and conformation of the photoprobe that are very similar to the ones reported for 1) the high resolution cocrystal structure of epothilone A with an α,β-tubulin complex and for 2) a saturation transfer difference NMR and transferred NOESY NMR study of dimeric and polymerized tubulin. Our findings thus provide additional support for these models as physiologically the most relevant among several modes of binding that have been proposed for epothilone A in the taxane pocket of β-tubulin.

Coumestrol suppresses proliferation of ES2 human epithelial ovarian cancer cells

Coumestrol, which is predominantly found in soybean products as a phytoestrogen, has cancer preventive activities in estrogen-responsive carcinomas. However, effects and molecular targets of coumestrol have not been reported for epithelial ovarian cancer (EOC). In the present study, we demonstrated that coumestrol inhibited viability and invasion and induced apoptosis of ES2 (clear cell-/serous carcinoma origin) cells. In addition, immunoreactive PCNA and ERBB2, markers of proliferation of ovarian carcinoma, were attenuated in their expression in coumestrol-induced death of ES2 cells. Phosphorylation of AKT, p70S6K, ERK1/2, JNK1/2, and p90RSK was inactivated by coumestrol treatment in a dose- and time-dependent manner as determined in western blot analyses. Moreover, PI3K inhibitors enhanced effects of coumestrol to decrease phosphorylation of AKT, p70S6K, S6, and ERK1/2. Furthermore, coumestrol has strong cancer preventive effects as compared to other conventional chemotherapeutics on proliferation of ES2 cells. In conclusion, coumestrol exerts chemotherapeutic effects via PI3K and ERK1/2 MAPK pathways and is a potentially novel treatment regimen with enhanced chemoprevention activities against progression of EOC.

Morphologic, Immunophenotypic, and Molecular Features of Epithelial Ovarian Cancer

Epithelial ovarian cancer comprises a heterogeneous group of tumors. The four most common subtypes are serous, endometrioid, clear cell, and mucinous carcinoma. Less common are transitional cell tumors, including transitional cell carcinoma and malignant Brenner tumor. While in the past these subtypes were grouped together and designated as epithelial ovarian tumors, these tumor types are now known to be separate entities with distinct clinical and biologic behaviors. From a therapeutic standpoint, current regimens employ standard chemotherapy based on stage and grade rather than histotype. However, this landscape may change in the era of personalized therapy, given that most subtypes (with the exception of high-grade serous carcinoma) are relatively resistant to chemotherapy. It is now well-accepted that high-grade and low-grade serous carcinomas represent distinct entities rather than a spectrum of the same tumor type. While they are similar in that patients present with advanced-stage disease, their histologic and molecular features are entirely different. High-grade serous carcinoma is associated with TP53 mutations, whereas low-grade serous carcinomas are associated with BRAF and KRAS mutations. Endometrioid and clear cell carcinomas typically present as early-stage disease and are frequently associated with endometriosis. Mucinous carcinomas typically present as large unilateral masses and often show areas of mucinous cystadenoma and mucinous borderline tumor. It must be emphasized that primary mucinous carcinomas are uncommon tumors, and metastasis from other sites such as the appendix, colon, stomach, and pancreaticobiliary tract must always be considered in the differential diagnosis. Lastly, transitional cell tumors of the ovary, specifically malignant Brenner tumors, are quite uncommon. High-grade serous carcinoma often has a transitional cell pattern, and adequate sampling in most cases shows more typical areas of serous carcinoma. Immunohistochemical markers are routinely employed in the diagnosis of epithelial ovarian carcinomas. However, molecular testing of these tumors, unlike in endometrial carcinoma, is not routinely used in clinical practice.

The expression and significance of WT1 in xenotransplanted ovarian carcinoma treated by paclitaxel

In this study, the authors investigated the expression and significance of WTl in xenotransplanted ovarian carcinoma cell SKOV3 of nude mice treated with paclitaxel. Xenotransplanted ovarian carcinoma was established in nude mice using the SKOV3 cell line. The mice were randomized into the treatment group with paclitaxel and control group with normal sodium. The sizes of the xenotransplanted tumors were measured and the tumor specimens were confirmed by routine hemotoxylin-eosin (H&E) staining. The apoptosis index was then assayed using flow cytometry. WTl and bcl-2 expression were detected with immunohistochemistry, and WT1 mRNA expression was determined by reverse transcriptase polymerase chain reaction (RT-PCR). The authors found that the growth of the xenotransplanted tumor was inhibited by paclitaxel therapy. Compared to the control group, the apoptosis rate was significantly increased in the treatment group (p < 0.05). At the same time, the expression of WTl, bcl-2 and WTI, mRNA were significantly decreased in the paclitaxel therapy group (p < 0.05). The authors conclude that the WTl gene may play an important role during apoptosis of ovarian carcinoma and the mechanism may be closely related to bcl-2.

Krukenberg tumor in a 18-year-old-female: a rare case

BACKGROUND

Krukenberg tumors mostly occur after 40 years. Metastatic ovarian tumors in young age are very rare.

CASE

A 18-year-old female presented with colon cancer which was accompanied by Krukenberg tumor. The present case was a very rare case of metastatic ovarian tumor in very young age. The present patient presented with abdominal pain. On examination, colon tumor was detected and bilateral ovary were almost normal with only slight swelling. During the operation for colon tumor, biopsy of bilateral ovary was performed for histopathological evaluation. Although there were no specific findings in bilateral ovary, microscopic examination revealed poorly differentiated adenocarcinoma, diffusely invading the ovarian parenchyma. Diagnosis of colon cancer was made postoperatively and ovarian Krukenberg tumor was confirmed.

CONCLUSION

In case of suspecting colon cancer even in very young patient with normal ovary, biopsy of ovary should be considered for the diagnosis of Krukenberg tumor.

Identification of biomarkers and pathway-related modules involved in ovarian cancer based on topological centralities

PURPOSE

The present study was designed to explore the significant biomarkers and pathway-related modules for predicting the effects of eribulin relative to paclitaxel in ovarian cancer.

METHODS

The gene expression data E-GEOD-50831 were downloaded from the European Bioinformatics Institute (EBI) database. Differentially expressed genes (DEGs) were screened. Subsequently, differential coexpression network was constructed. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and pathway-related modules mining were conducted. Topological centralities (degree, betweenness, closeness and stress) analyses for coexpression network and pathway-related modules were performed to explore hub genes and the most significant pathways. Then, we verified our findings in an independent sample set via RT-PCR and Western blotting.

RESULTS

Centralities results of ESCO1, CDC27and MCM4 ranked the top five. Moreover, among the top 10% hub genes, CDC27, MCM4 and SOS1 were pathway-enriched genes in two networks. A total of 5 and 6 pathway-related modules were obtained under two drugs treatment. Based analyses of degree, betweenness and other centralities, DNA replication pathway-related module was the most significant under paclitaxel treatment, while cell cycle pathway-related module was the most significant under eribulin treatment. RT-PCR and Western blotting results were consistent with the bioinformatics results. The expression level of MCM4 was remarkably decreased under eribulin treatment relative to paclitaxel.

CONCLUSIONS

The inhibition of ovarian cancer growth by paclitaxel and eribulin might be connected with downregulation of cell cycle and DNA replication pathway. Moreover, MCM4 signature might be a potential biomarker to predict the effect of eribulin in ovarian cancer.

Expression of Nestin and CD133 in serous ovarian carcinoma

Pupose: Nestin and CD133 are regarded as putative markers of cancer stem cells (CSCs) and related to poor prognosis in various cancer sites. Since few studies have focused on their role in ovarian cancer, we aimed to investigate their predictive value and association with neoangiogenesis.

METHODS

Immunohistochemical analysis for nestin and CD133 was performed on 85 serous ovarian carcinoma tumor samples using tissue microarray technique. Nestin immunoreactivity was detected in both tumor and endothelial cells, whilst CD133 was only identified in tumor cells. CD34 endothelial expression was used to assess intratumor microvessel density (MVD).

RESULTS

Of the tissue samples 49.4% were nestin-positive and 24.7% were positive for CD133. In both univariate and multivariate analysis nestin or CD133 expressions in tumor cells were not significantly associated with clinicopathological parameters (age, serum CA125, peritoneal carcinomatosis, malignant ascites, tumor grade). However, in multivariate analysis nestin expression in tumor cells proved to be an independent prognostic factor, associated with poorer survival and time to progression (p=0.025 and p=0.05, respectively). This has not been achieved for CD133. Furthermore, a significant concordance between nestin endothelial expression (nestin-determined MVD) and CD34-determined MVD was achieved.

CONCLUSION

In addition to the well-known clinicopathological characteristics, tumor expression of nestin might be a valuable prognostic factor for survival in patients with advanced ovarian cancer. With regard to its endothelial expression, nestin might be as reliable as CD34 for quantifying tumor angiogenesis. Further investigation is justified in order to better clarify the role of these biomarkers.

ACTH-secreting pancreatic neuroendocrine carcinoma with ovarian and pelvic metastases causing Cushing's syndrome: a case report

Adrenocorticotropin hormone (ACTH)-secreting pancreatic neuroendocrine carcinoma (NEC) with ovarian and pelvic metastases causing Cushing's syndrome is very rare and might be misdiagnosed. We describe a case of ACTH-secreting pancreatic poorly differentiated NEC developing bilateral ovarian and pelvic metastases. A 27-year-old woman presented with thirst, polydipsia, fatigue and poorly controlled hyperglycemia. Laboratory and imaging investigations revealed hypokalemia, hyperglycaemia, ACTH-dependent hypercortisolemia and a 12-cm mass at the junction of body and tail of the pancreas with ovarian and pelvic nodules. The patient underwent partial pancreatectomy and splenectomy, uterectomy, bilateral oophorectomy, and excision of peritoneal nodules. Tumors in pancreas, ovaries and pelvis were diagnosed as poor-differentiated NEC. After 19-month chemotherapy, she developed pelvic metastasis. The tumor in our case is a large, poorly differentiated NEC secreting ACTH and causing CS, with ovarian metastases. To our knowledge, this new additional case of ACTH-secreting pancreatic NEC with ovarian metastases would add to the better understanding of this tumor.

Roles of Cx43 and AKAP95 in ovarian cancer tissues in G1/S phase

OBJECTIVE

The purpose of this study was to investigate the expression of A-kinase anchor protein 95 (AKAP95), cell cycle protein E1 (cyclinE1) and D1 (cyclinD1), and gap junction protein connexin 43 (Cx43) in ovarian cancer tissues, the relationship between four proteins and clinicopathologic parameters, and the correlation between these proteins.

METHODS

The expression of proteins in 54 cases of ovarian cancer tissues was detected by immunohistochemical method.

RESULTS

The positive expression rates of AKAP95, cyclinD1 and cyclinE1 in ovarian cancer tissues were 72.22%, 66.67% and 79.63%, respectively, which were higher than that of ovarian pericarcinoma tissues expressing as 33.33%, 25% and 8.30% (P<0.05). The positive expression rate of Cx43 in ovarian cancer tissues was 40.74%, which was lower than that of ovarian pericarcinoma tissues expressing as 75%; respectively, and the difference was statistically significant between groups (P<0.05). The expression of cyclinD1 in ovarian cancer tissues was related to the histologic type (P<0.05) while it showed no correlation with the degree of differentiation (P>0.05). Additionally, the expression of AKAP95, Cx43 and cyclinE1 in ovarian cancer tissues showed no correlation with the degree of differentiation or the histologic type (P>0.05). Protein expressions of AKAP95, Cx43 and cyclinE1 were correlated with each other (P<0.05), and the expressions of cyclinD1, cyclinE1 and Cx43 were also correlated with each other (P<0.05). However, AKAP95 and cyclinD1 showed no correlation (P>0.05).

CONCLUSION

AKAP95, cyclinD1 and cyclinE1 play an important role in promoting the process of ovarian cancer formation. The tumor inhibitory effects of Cx43 protein on the pathogenesis of ovarian cancer were weakened. The expression of cyclinD1 in ovarian cancer tissues is related to the histologic type while it shows no correlation with the degree of differentiation. Additionally, the expression of AKAP95, Cx43 and cyclinE1 in ovarian cancer tissues shows no correlation with the degree of differentiation or the histologic type. AKAP95 expression is correlated with Cx43 and cyclinE1 expression; Cx43 expression is correlated with AKAP95, cyclinD1 and cyclinE1 expression; cyclinE1 expression is correlated with AKAP95, Cx43, cyclinD1 expression; cyclinD1 expression is correlated with Cx43 and cyclinE1 expression, while AKAP95 and cyclinD1 show no correlation.