High-grade serous ovarian cancer: the clone wars

ST6Gal-I-mediated sialylation of the epidermal growth factor receptor modulates cell mechanics and enhances invasion

Heterogeneity within the glycocalyx influences cell adhesion mechanics and signaling. However, the role of specific glycosylation subtypes in influencing cell mechanics via alterations of receptor function remains unexplored. It has been shown that the addition of sialic acid to terminal glycans impacts growth, development, and cancer progression. In addition, the sialyltransferase ST6Gal-I promotes epidermal growth factor receptor (EGFR) activity, and we have shown EGFR is an 'allosteric mechano-organizer' of integrin tension. Here, we investigated the impact of ST6Gal-I on cell mechanics. Using DNA-based tension gauge tether probes of variable thresholds, we found that high ST6Gal-I activity promotes increased integrin forces and spreading in Cos-7 and OVCAR3, OVCAR5, and OV4 cancer cells. Further, employing inhibitors and function-blocking antibodies against β1, β3, and β5 integrins and ST6Gal-I targets EGFR, tumor necrosis factor receptor, and Fas cell surface death receptor, we validated that the observed phenotypes are EGFR-specific. We found that while tension, contractility, and adhesion are extracellular-signal-regulated kinase pathway-dependent, spreading, proliferation, and invasion are phosphoinositide 3-kinase-Akt serine/threonine kinase dependent. Using total internal reflection fluorescence microscopy and flow cytometry, we also show that high ST6Gal-I activity leads to sustained EGFR membrane retention, making it a key regulator of cell mechanics. Our findings suggest a novel sialylation-dependent mechanism orchestrating cellular mechanics and enhancing cell motility via EGFR signaling.

Combined inhibition of IL‑6 and IL‑8 pathways suppresses ovarian cancer cell viability and migration and tumor growth

Ovarian cancer is the most lethal gynecological cancer type in the United States. The success of current chemotherapies is limited by chemoresistance and side effects. Targeted therapy is a promising future direction for cancer therapy. In the present study, the efficacy of co‑targeting IL‑6 and IL‑8 in human ovarian cancer cells by bazedoxifene (Baze) + SCH527123 (SCH) treatment was examined. ELISA, cell viability, cell proliferation, cell migration, cell invasion, western blotting and peritoneal ovarian tumor mouse model analyses were performed to analyze the expression levels of IL‑6 and IL‑8, tumor growth, tumor migration and invasion, and the possible pathways of human ovarian cancer cell lines (SKOV3, CAOV3 and OVCAR3) and patient‑derived OV75 ovarian cancer cells. Each cell line was treated by monotherapy or combination therapy. The results demonstrated that IL‑6 and IL‑8 were secreted by human ovarian cancer cell lines. Compared with the DMSO control, the combination of IL‑6/glycoprotein 130 inhibitor Baze and IL‑8 inhibitor SCH synergistically inhibited cell viability in ovarian cancer cells. Baze + SCH also inhibited cell migration and invasion, suppressed ovarian tumor growth and inhibited STAT3 and AKT phosphorylation, as well as survivin expression. Therefore, co‑targeting the IL‑6 and IL‑8 signaling pathways may be an effective approach for ovarian cancer treatment.

Epigenetic Therapy Augments Classic Chemotherapy in Suppressing the Growth of 3D High-Grade Serous Ovarian Cancer Spheroids over an Extended Period of Time

Recurrent high-grade serous ovarian cancer (HGSC) is clinically very challenging and prematurely shortens patients’ lives. Recurrent ovarian cancer is characterized by high tumor heterogeneity; therefore, it is susceptible to epigenetic therapy in classic 2D tissue culture and rodent models. Unfortunately, this success has not translated well into clinical trials. Utilizing a 3D spheroid model over a period of weeks, we were able to compare the efficacy of classic chemotherapy and epigenetic therapy on recurrent ovarian cancer cells. Unexpectedly, in our model, a single dose of paclitaxel alone caused the exponential growth of recurrent high-grade serous epithelial ovarian cancer over a period of weeks. In contrast, this effect is not only opposite under treatment with panobinostat, but panobinostat reverses the repopulation of cancer cells following paclitaxel treatment. In our model, we also demonstrate differences in the drug-treatment sensitivity of classic chemotherapy and epigenetic therapy. Moreover, 3D-derived ovarian cancer cells demonstrate induced proliferation, migration, invasion, cancer colony formation and chemoresistance properties after just a single exposure to classic chemotherapy. To the best of our knowledge, this is the first evidence demonstrating a critical contrast between short and prolonged post-treatment outcomes following classic chemotherapy and epigenetic therapy in recurrent high-grade serous ovarian cancer in 3D culture.

Histological patterns and intra-tumor heterogeneity as prognostication tools in high grade serous ovarian cancers

OBJECTIVE

High grade serous ovarian carcinoma (HGSOC) is the most common type of malignant ovarian neoplasm and the main cause of ovarian cancer related deaths worldwide. Although novel biomarkers such as homologous recombination deficiency testing have been implemented into the clinical decision-making algorithm since diagnosis, morphological classification and immunohistochemistry analysis are essential for diagnostic purpose. This study aims at identifying histologic and clinical features that can be predictive of patients' prognosis.

METHODS

Morphological and architectural characterization including SET (Solid-Endometroid-Transitional)/Classic features was carried out in a cohort of 234 patients analyzing 695 slides. From each slide tumor infiltrating lymphocyte (TILs), the presence of necrosis, the number of mitoses, the presence of psammoma bodies, giant cells and atypical mitoses were recorded. Morphological heterogeneity was quantified by the Shannon's diversity index (SDI) considering the percentage of each architectural pattern per patient's slide.

RESULTS

The frequency of architectural patterns and morphological variables varied with respect of the surgical strategy (primary debulking surgery vs interval surgery after neoadjuvant chemotherapy). HGSOCs exhibiting SET features had a longer overall as well as progression free survival. Among SET features, pseudo-endometrioid and transitional like patterns had the best outcome, while it was heterogenous for solid pattern, that had better outcome for BRCA 1 negative and less heterogeneous tumors. In patients submitted to neoadjuvant chemotherapy a higher intratumor heterogeneity as defined by SDI was a negative independent prognostic factor.

CONCLUSIONS

A comprehensive histological examination considering architectural patterns and their heterogeneity can help in prognostication of HGSOCs.

Clonal Evolution of Multiple Myeloma-Clinical and Diagnostic Implications

Plasma cell dyscrasias are a heterogeneous group of diseases characterized by the expansion of bone marrow plasma cells. Malignant transformation of plasma cells depends on the continuity of events resulting in a sequence of well-defined disease stages, from monoclonal gammopathy of undetermined significance (MGUS) through smoldering myeloma (SMM) to symptomatic multiple myeloma (MM). Evolution of a pre-malignant cell into a malignant cell, as well as further tumor progression, dissemination, and relapse, require development of multiple driver lesions conferring selective advantage of the dominant clone and allowing subsequent evolution under selective pressure of microenvironment and treatment. This process of natural selection facilitates tumor plasticity leading to the formation of genetically complex and heterogenous tumors that are notoriously difficult to treat. Better understanding of the mechanisms underlying tumor evolution in MM and identification of lesions driving the evolution from the premalignant clone is therefore a key to development of effective treatment and long-term disease control. Here, we review recent advances in clonal evolution patterns and genomic landscape dynamics of MM, focusing on their clinical implications.

Improving personalized tumor growth predictions using a Bayesian combination of mechanistic modeling and machine learning

BACKGROUND

In clinical practice, a plethora of medical examinations are conducted to assess the state of a patient's pathology producing a variety of clinical data. However, investigation of these data faces two major challenges. Firstly, we lack the knowledge of the mechanisms involved in regulating these data variables, and secondly, data collection is sparse in time since it relies on patient's clinical presentation. The former limits the predictive accuracy of clinical outcomes for any mechanistic model. The latter restrains any machine learning algorithm to accurately infer the corresponding disease dynamics.

METHODS

Here, we propose a novel method, based on the Bayesian coupling of mathematical modeling and machine learning, aiming at improving individualized predictions by addressing the aforementioned challenges.

RESULTS

We evaluate the proposed method on a synthetic dataset for brain tumor growth and analyze its performance in predicting two relevant clinical outputs. The method results in improved predictions in almost all simulated patients, especially for those with a late clinical presentation (>95% patients show improvements compared to standard mathematical modeling). In addition, we test the methodology in two additional settings dealing with real patient cohorts. In both cases, namely cancer growth in chronic lymphocytic leukemia and ovarian cancer, predictions show excellent agreement with reported clinical outcomes (around 60% reduction of mean squared error).

CONCLUSIONS

We show that the combination of machine learning and mathematical modeling approaches can lead to accurate predictions of clinical outputs in the context of data sparsity and limited knowledge of disease mechanisms.

AdipoRon: A Novel Insulin Sensitizer in Various Complications and the Underlying Mechanisms: A Review

BACKGROUND

AdipoRon is the first synthetic analog of endogenous adiponectin, an adipose tissue-derived hormone. AdipoRon possesses pharmacological properties similar to adiponectin and its ability to bind and activate the adipoR1 and adipoR2 receptors makes it a suitable candidate for the treatment of a multitude of disorders.

OBJECTIVE

In the present review, an attempt was made to compile and discuss the efficacy of adipoRon against various disorders.

RESULTS

AdipoRon is a drug that acts not only in metabolic diseases but in other conditions unrelated to energy metabolism. It is well- reported that adipoRon exhibits strong anti-obesity, anti-diabetic, anticancer, anti-depressant, anti-ischemic, anti-hypertrophic properties and also improves conditions like post-traumatic stress disorder, anxiety, and systemic sclerosis.

CONCLUSION

A lot is known about its effects in experimental systems, but the translation of this knowledge to the clinic requires studies which, for many of the potential target conditions, have yet to be carried out. The beneficial effects of AdipoRon in novel clinical conditions will suggest an underlying pathophysiological role of adiponectin and its receptors in previously unsuspected settings.

A novel small molecule LLL12B inhibits STAT3 signaling and sensitizes ovarian cancer cell to paclitaxel and cisplatin

Ovarian cancer is the fifth most common cause of cancer deaths among American women. Platinum and taxane combination chemotherapy represents the first-line approach for ovarian cancer, but treatment success is often limited by chemoresistance. Therefore, it is necessary to find new drugs to sensitize ovarian cancer cells to chemotherapy. Persistent activation of Signal Transducer and Activator of Transcription 3 (STAT3) signaling plays an important role in oncogenesis. Using a novel approach called advanced multiple ligand simultaneous docking (AMLSD), we developed a novel nonpeptide small molecule, LLL12B, which targets the STAT3 pathway. In this study, LLL12B inhibited STAT3 phosphorylation (tyrosine 705) and the expression of its downstream targets, which are associated with cancer cell proliferation and survival. We showed that LLL12B also inhibits cell viability, migration, and proliferation in human ovarian cancer cells. LLL12B combined with either paclitaxel or with cisplatin demonstrated synergistic inhibitory effects relative to monotherapy in inhibiting cell viability and LLL12B-paclitaxel or LLL12B-cisplatin combination exhibited greater inhibitory effects than cisplatin-paclitaxel combination in ovarian cancer cells. Furthermore, LLL12B-paclitaxel or LLL12B-cisplatin combination showed more significant in inhibiting cell migration and growth than monotherapy in ovarian cancer cells. In summary, our results support the novel small molecule LLL12B as a potent STAT3 inhibitor in human ovarian cancer cells and suggest that LLL12B in combination with the current front-line chemotherapeutic drugs cisplatin and paclitaxel may represent a promising approach for ovarian cancer therapy.

3D Bioprinted cancer models: Revolutionizing personalized cancer therapy

After cardiovascular disease, cancer is the leading cause of death worldwide with devastating health and economic consequences, particularly in developing countries. Inter-patient variations in anti-cancer drug responses further limit the success of therapeutic interventions. Therefore, personalized medicines approach is key for this patient group involving molecular and genetic screening and appropriate stratification of patients to treatment regimen that they will respond to. However, the knowledge related to adequate risk stratification methods identifying patients who will respond to specific anti-cancer agents is still lacking in many cancer types. Recent advancements in three-dimensional (3D) bioprinting technology, have been extensively used to generate representative bioengineered tumor in vitro models, which recapitulate the human tumor tissues and microenvironment for high-throughput drug screening. Bioprinting process involves the precise deposition of multiple layers of different cell types in combination with biomaterials capable of generating 3D bioengineered tissues based on a computer-aided design. Bioprinted cancer models containing patient-derived cancer and stromal cells together with genetic material, extracellular matrix proteins and growth factors, represent a promising approach for personalized cancer therapy screening. Both natural and synthetic biopolymers have been utilized to support the proliferation of cells and biological material within the personalized tumor models/implants. These models can provide a physiologically pertinent cell-cell and cell-matrix interactions by mimicking the 3D heterogeneity of real tumors. Here, we reviewed the potential applications of 3D bioprinted tumor constructs as personalized in vitro models in anticancer drug screening and in the establishment of precision treatment regimens.

A Comprehensive Molecular and Clinical Analysis of the piRNA Pathway Genes in Ovarian Cancer

Simple Summary

Although ovarian cancer (OC) is one of the most lethal gynecological cancers, its development and progression remain poorly understood. The piRNA pathway is important for transposon defense and genome stability. piRNA maturation and function involve a number of genes known as the piRNA pathway genes. These genes have recently been implicated in cancer development and progression but information about their role in OC is limited. Our work aimed to provide a better understanding of the roles of piRNA pathway genes in OC. Through analyzing changes in the abundance of 10 piRNA pathway genes, we discovered gene expression differences in benign vs. cancer, chemosensitive vs. chemoresistant and post hormone treatment in OC samples and cells. Furthermore, we observed the differential effects of these genes on patient survival and OC cell invasion. Overall, this work supports a role of the piRNA pathway genes in OC progression and encourages further study of their clinical relevance.

Abstract

Ovarian cancer (OC) is one of the most lethal gynecological malignancies, yet molecular mechanisms underlying its origin and progression remain poorly understood. With increasing reports of piRNA pathway deregulation in various cancers, we aimed to better understand its role in OC through a comprehensive analysis of key genes: PIWIL1-4, DDX4, HENMT1, MAEL, PLD6, TDRD1,9 and mutants of PIWIL1 (P1∆17) and PIWIL2 (PL2L60). High-throughput qRT-PCR (n = 45) and CSIOVDB (n = 3431) showed differential gene expression when comparing benign ovarian tumors, low grade OC and high grade serous OC (HGSOC). Significant correlation of disparate piRNA pathway gene expression levels with better progression free, post-progression free and overall survival suggests a complex role of this pathway in OC. We discovered PIWIL3 expression in chemosensitive but not chemoresistant primary HGSOC cells, providing a potential target against chemoresistant disease. As a first, we revealed that follicle stimulating hormone increased PIWIL2 expression in OV-90 cells. PIWIL1, P1∆17, PIWIL2, PL2L60 and MAEL overexpression in vitro and in vivo decreased motility and invasion of OVCAR-3 and OV-90 cells. Interestingly, P1∆17 and PL2L60, induced increased motility and invasion compared to PIWIL1 and PIWIL2. Our results in HGSOC highlight the intricate role piRNA pathway genes play in the development of malignant neoplasms.

NGS-guided precision oncology in metastatic breast and gynecological cancer: first experiences at the CCC Munich LMU

Purpose

Comprehensive genomic profiling identifying actionable molecular alterations aims to enable personalized treatment for cancer patients. The purpose of this analysis was to retrospectively assess the impact of personalized recommendations made by a multidisciplinary tumor board (MTB) on the outcome of patients with breast or gynecological cancers, who had progressed under standard treatment. Here, first experiences of our Comprehensive Cancer Center Molecular Tumor Board are reported.

Methods

All patients were part of a prospective local registry. 95 patients diagnosed with metastatic breast cancer or gynecological malignancies underwent extended molecular profiling. From May 2017 through March 2019, the MTB reviewed all clinical cases considering tumor profile and evaluated molecular alterations regarding further diagnostic and therapeutic recommendations.

Results

95 patients with metastatic breast or gynecological cancers were discussed in the MTB (68% breast cancer, 20% ovarian cancer, 5% cervical cancer, 3% endometrial cancer and 4% others). Genes with highest mutation rate were PIK3CA and ERBB2. Overall, 34 patients (36%) received a biomarker-based targeted therapy recommendation. Therapeutic recommendations were implemented in nine cases; four patients experienced clinical benefit with a partial response or disease stabilization lasting over 4 months.

Conclusion

In the setting of a multidisciplinary molecular tumor board, a small but clinically meaningful group of breast and gynecological cancer patients benefits from comprehensive genomic profiling. Broad and successful implementation of precision medicine is complicated by patient referral at late stage disease and limited access to targeted agents and early clinical trials.

Trial registration number

284-10 (03.05.2018).

Integrative radiogenomics for virtual biopsy and treatment monitoring in ovarian cancer

BACKGROUND

Ovarian cancer survival rates have not changed in the last 20 years. The majority of cases are High-grade serous ovarian carcinomas (HGSOCs), which are typically diagnosed at an advanced stage with multiple metastatic lesions. Taking biopsies of all sites of disease is infeasible, which challenges the implementation of stratification tools based on molecular profiling.

MAIN BODY

In this review, we describe how these challenges might be overcome by integrating quantitative features extracted from medical imaging with the analysis of paired genomic profiles, a combined approach called radiogenomics, to generate virtual biopsies. Radiomic studies have been used to model different imaging phenotypes, and some radiomic signatures have been associated with paired molecular profiles to monitor spatiotemporal changes in the heterogeneity of tumours. We describe different strategies to integrate radiogenomic information in a global and local manner, the latter by targeted sampling of tumour habitats, defined as regions with distinct radiomic phenotypes.

CONCLUSION

Linking radiomics and biological correlates in a targeted manner could potentially improve the clinical management of ovarian cancer. Radiogenomic signatures could be used to monitor tumours during the course of therapy, offering additional information for clinical decision making. In summary, radiogenomics may pave the way to virtual biopsies and treatment monitoring tools for integrative tumour analysis.

Multiomic Analysis of Subtype Evolution and Heterogeneity in High-Grade Serous Ovarian Carcinoma

Multiple studies have identified transcriptome subtypes of high-grade serous ovarian carcinoma (HGSOC), but their interpretation and translation are complicated by tumor evolution and polyclonality accompanied by extensive accumulation of somatic aberrations, varying cell type admixtures, and different tissues of origin. In this study, we examined the chronology of HGSOC subtype evolution in the context of these factors using a novel integrative analysis of absolute copy-number analysis and gene expression in The Cancer Genome Atlas complemented by single-cell analysis of six independent tumors. Tumor purity, ploidy, and subclonality were reliably inferred from different genomic platforms, and these characteristics displayed marked differences between subtypes. Genomic lesions associated with HGSOC subtypes tended to be subclonal, implying subtype divergence at later stages of tumor evolution. Subclonality of recurrent HGSOC alterations was evident for proliferative tumors, characterized by extreme genomic instability, absence of immune infiltration, and greater patient age. In contrast, differentiated tumors were characterized by largely intact genome integrity, high immune infiltration, and younger patient age. Single-cell sequencing of 42,000 tumor cells revealed widespread heterogeneity in tumor cell type composition that drove bulk subtypes but demonstrated a lack of intrinsic subtypes among tumor epithelial cells. Our findings prompt the dismissal of discrete transcriptome subtypes for HGSOC and replacement by a more realistic model of continuous tumor development that includes mixtures of subclones, accumulation of somatic aberrations, infiltration of immune and stromal cells in proportions correlated with tumor stage and tissue of origin, and evolution between properties previously associated with discrete subtypes. SIGNIFICANCE: This study infers whether transcriptome-based groupings of tumors differentiate early in carcinogenesis and are, therefore, appropriate targets for therapy and demonstrates that this is not the case for HGSOC.

Dexmedetomidine Regulates Proliferation, Apoptosis, Migration, and Invasion in Ovarian Cancer Cells via MiR-155-HIF-1α Axis

BACKGROUND Dexmedetomidine (DMED) is widely used as an adjuvant anesthetic, but how DMED regulates biological behavior of OC cells remains an area of active research. This study investigated the mechanism by which DMED regulates the proliferation, apoptosis, migration, and invasion abilities of OC cells. MATERIAL AND METHODS We determined the optimal concentration of DMED for use in treating SKOV3 cells. The biological activities of DMED-treated SKOV3 cells following transfection with miR-155 inhibitor or si-HIF-1alpha were measured by CCK-8 assay, flow cytometry, wound healing assay, and Transwell assay. qRT-PCR and Western blot analysis were performed to assess the expression levels of apoptotic-related caspase-3 and Mcl-1. Luciferase reporter assay verified the targeting relationship of miR-155 and HIF-1alpha. RESULTS miR-155 was downregulated while HIF-1alpha was upregulated in SKOV3 cells. DMED dose-dependently reduced HIF-1alpha expression in SKOV3 cells, and upregulated the expression of miR-155. DMED inhibited the proliferation, migration and invasion abilities of OC cells, but also contributed to apoptosis of SKOV3 cells, while transfection of miR-155 inhibitor inhibited the effect of DMED on SKOV3 cells. In contrast, transfection with si-HIF-1alpha enhanced the effects of DMED on SKOV3 cells. HIF-1alpha was found to be a target gene of miR-155. CONCLUSIONS Our results suggest that DMED blocks cell proliferation, migration, and invasion and accelerates cell apoptosis in OC.

MUS81 Participates in the Progression of Serous Ovarian Cancer Associated With Dysfunctional DNA Repair System

Objective: Methyl methanesulfonate ultraviolet sensitive gene clone 81 (MUS81) is a structure-specific endonuclease that plays a pivotal role in the DNA repair system of cancer cells. In this study, we aim to elucidate the potential association between the dysfunction of MUS81 and the progression of Serous Ovarian Cancer (SOC).

Methods: To investigate the association between MUS81 and prognosis of SOC, immunohistochemistry technology and qPCR were used to analyze the level of MUS81 expression, and transcriptional profile analysis and protein interaction screening chip were used to explore the MUS81 related signal pathways. Random amplified polymorphic DNA (RAPD) analysis, immunofluorescence and comet assays were further performed to evaluate genomic instability and DNA damage status of transduced SOC cells. Experiments both in vitro and in vivo were conducted to verify the impact of MUS81 silencing on chemotherapeutic drug sensitivity of SOC.

Results: The overexpression of MUS81 in SOC tissues was related to poor clinical outcomes. The transcriptional chip data showed that MUS81 was involved in multiple pathways associated with DNA repair. Deficiency of MUS81 intensified the genome instability of SOC cells, promoted the emergence of DSBs and restrained the formation of RAD51 foci in SOC cells with exposure to UV. Furthermore, downregulation of MUS81 enhanced the sensitivity to Camptothecin and Olaparib in SOC cell lines and xenograft model.

Conclusions: MUS81 is involved in the progression of SOC and inhibition of MUS81 could augment the susceptibility to chemotherapeutic agents. MUS81 might represent a novel molecular target for SOC chemotherapy.

Sox2 promotes expression of the ST6Gal-I glycosyltransferase in ovarian cancer cells

Background

The ST6Gal-I glycosyltransferase, which adds α2–6-linked sialic acids to N-glycosylated proteins is upregulated in a wide range of malignancies including ovarian cancer. Prior studies have shown that ST6Gal-I-mediated sialylation of select surface receptors remodels intracellular signaling to impart cancer stem cell (CSC) characteristics. However, the mechanisms that contribute to ST6Gal-I expression in stem-like cancer cells are poorly understood.

Results

Herein, we identify the master stem cell transcription factor, Sox2, as a novel regulator of ST6Gal-I expression. Interestingly, SOX2 and ST6GAL1 are located within the same tumor-associated amplicon, 3q26, and these two genes exhibit coordinate gains in copy number across multiple cancers including ~ 25% of ovarian serious adenocarcinomas. In conjunction with genetic co-amplification, our studies suggest that Sox2 directly binds the ST6GAL1 promoter to drive transcription. ST6Gal-I expression is directed by at least four distinct promoters, and we identified the P3 promoter as the predominant promoter utilized by ovarian cancer cells. Chromatin Immunoprecipitation (ChIP) assays revealed that Sox2 binds regions proximal to the P3 promoter. To confirm that Sox2 regulates ST6Gal-I expression, Sox2 was either overexpressed or knocked-down in various ovarian cancer cell lines. Sox2 overexpression induced an increase in ST6Gal-I mRNA and protein, as well as surface α2–6 sialylation, whereas Sox2 knock-down suppressed levels of ST6Gal-I mRNA, protein and surface α2–6 sialylation.

Conclusions

These data suggest a process whereby SOX2 and ST6GAL1 are coordinately amplified in cancer cells, with the Sox2 protein then binding the ST6GAL1 promoter to further augment ST6Gal-I expression. Our collective results provide new insight into mechanisms that upregulate ST6Gal-I expression in ovarian cancer cells, and also point to the possibility that some of the CSC characteristics commonly attributed to Sox2 may, in part, be mediated through the sialyltransferase activity of ST6Gal-I.

Epithelial ovarian cancer risk: A review of the current genetic landscape

Ovarian cancer is the fourth most common cause of cancer-related death in women in the developed world, and one of the most heritable cancers. One of the most significant risk factors for epithelial ovarian cancer (EOC) is a family history of breast and/or ovarian cancer. Combined risk factors can be used in models to stratify risk of EOC, and aid in decisions regarding risk-reduction strategies. Germline pathogenic variants in EOC susceptibility genes including those involved in homologous recombination and mismatch repair pathways are present in approximately 22% to 25% of EOC. These genes are associated with an estimated lifetime risk of EOC of 13% to 60% for BRCA1 variants and 10% to 25% for BRCA2 variants, with lower risks associated with remaining genes. Genome-wide association studies have identified single nucleotide polymorphisms (SNPs) thought to explain an additional 6.4% of the familial risk of ovarian cancer, with 34 susceptibility loci identified to date. However, an unknown proportion of the genetic component of EOC risk remains unexplained. This review comprises an overview of individual genes and SNPs suspected to contribute to risk of EOC, and discusses use of a polygenic risk score to predict individual cancer risk more accurately.

Effect of dexmedetomidine anesthesia on perioperative levels of TNF-α and IL-6 in patients with ovarian cancer

Effect of continuous use of dexmedetomidine during general anesthesia on perioperative levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in patients undergoing radical resection of ovarian cancer was investigated. The initial treatment of ovarian cancer is mainly radical surgery. Most patients with ovarian cancer radical surgery can achieve good results, but the use of improper anesthetic drugs in radical surgery can easily lead to unstable patient vital signs. Therefore, the selection of appropriate anesthetic drugs has become the key to radical ovarian cancer surgery. There are few reports on the use of dexmedetomidine in anesthesia for ovarian cancer radical surgery. This study was performed to retrospectively analyze the case data of patients undergoing laparoscopic ovarian cancer radical surgery, and to compare the hemodynamics of dexmedetomidine anesthesia with midazolam anesthesia and the concentrations of TNF-α and IL-6, to provide reference for clinical implementation of ovarian cancer radical surgery. The hemodynamics of patients in the dexmedetomidine group were stable compared with the midazolam group. Serum TNF-α and IL-6 levels were significantly lower in the dexmedetomidine group than that in the midazolam group. If dexmedetomidine were continuously used during general anesthesia, the perioperative serum levels of TNF-α and IL-6 could be effectively reduced in patients undergoing radical resection of ovarian cancer, and the perioperative stress response was suppressed.

Interrelations of Sphingolipid and Lysophosphatidate Signaling with Immune System in Ovarian Cancer

The sphingolipid and lysophosphatidate regulatory networks impact diverse mechanisms attributed to cancer cells and the tumor immune microenvironment. Deciphering the complexity demands implementation of a holistic approach combined with higher-resolution techniques. We implemented a multi-modular integrative approach consolidating the latest accomplishments in gene expression profiling, prognostic/predictive modeling, next generation digital pathology, and systems biology for epithelial ovarian cancer. We assessed patient-specific transcriptional profiles using the sphingolipid/lysophosphatidate/immune-associated signature. This revealed novel sphingolipid/lysophosphatidate-immune gene-gene associations and distinguished tumor subtypes with immune high/low context. These were characterized by robust differences in sphingolipid-/lysophosphatidate-related checkpoints and the drug response. The analysis also nominates novel survival models for stratification of patients with CD68, LPAR3, SMPD1, PPAP2B, and SMPD2 emerging as the most prognostically important genes. Alignment of proprietary data with curated transcriptomic data from public databases across a variety of malignancies (over 600 categories; over 21,000 arrays) showed specificity for ovarian carcinoma. Our systems approach identified novel sphingolipid-lysophosphatidate-immune checkpoints and networks underlying tumor immune heterogeneity and disease outcomes. This holds great promise for delivering novel stratifying and targeting strategies.

Clinical Significance of Organic Anion Transporting Polypeptide Gene Expression in High-Grade Serous Ovarian Cancer

High-grade serous ovarian cancer (HGSOC) is considered the most deadly and frequently occurring type of ovarian cancer and is associated with various molecular compositions and growth patterns. Evaluating the mRNA expression pattern of the organic anion transporters (OATPs) encoded by SLCO genes may allow for improved stratification of HGSOC patients for targeted invention. The expression of SLCO mRNA and genes coding for putative functionally related ABC-efflux pumps, enzymes, pregnane-X-receptor, ESR1 and ESR2 (coding for estrogen receptors ERα and ERß) and HER-2 were assessed using RT-qPCR. The expression levels were assessed in a cohort of 135 HGSOC patients to elucidate the independent impact of the expression pattern on the overall survival (OS). For identification of putative regulatory networks, Graphical Gaussian Models were constructed from the expression data with a tuning parameter K varying between meaningful borders (Pils et al., 2012; Auer et al., 2015, 2017; Kurman and Shih Ie, 2016; Karam et al., 2017; Labidi-Galy et al., 2017; Salomon-Perzynski et al., 2017; Sukhbaatar et al., 2017). The final value used (K = 4) was determined by maximizing the proportion of explained variation of the corresponding LASSO Cox regression model for OS. The following two networks of directly correlated genes were identified: (i) SLCO2B1 with ABCC3 implicated in estrogen homeostasis; and (ii) two ABC-efflux pumps in the immune regulation (ABCB2/ABCB3) with ABCC3 and HER-2. Combining LASSO Cox regression and univariate Cox regression analyses, SLCO5A1 coding for OATP5A1, an estrogen metabolite transporter located in the cytoplasm and plasma membranes of ovarian cancer cells, was identified as significant and independent prognostic factor for OS (HR = 0.68, CI 0.49-0.93; p = 0.031). Furthermore, results indicated the benefits of patients with high expression by adding 5.1% to the 12.8% of the proportion of explained variation (PEV) for clinicopathological parameters known for prognostic significance (FIGO stage, age and residual tumor after debulking). Additionally, overlap with previously described signatures that indicated a more favorable prognosis for ovarian cancer patients was shown for SLCO5A1, the network ABCB2/ABCB3/ABCC4/HER2 as well as ESR1. Furthermore, expression of SLCO2A1 and PGDH, which are important for PGE₂ degradation, was associated with the non-miliary peritoneal tumor spreading. In conclusion, the present findings suggested that SLCOs and the related molecules identified as potential biomarkers in HGSOC may be useful for the development of novel therapeutic strategies.

Active DNA end processing in micronuclei of ovarian cancer cells

BACKGROUND

Ovarian cancer is one of the most deadly gynecological malignancies and inclined to recurrence and drug resistance. Previous studies showed that the tumorigenesis of ovarian cancers and their major histotypes are associated with genomic instability caused by defined sets of pathogenic mutations. In contrast, the mechanism that influences the development of drug resistance and disease recurrence is not well elucidated. Solid tumors are prone to chromosomal instability (CIN) and micronuclei formation (MN). Although MN is traditionally regarded as the outcome of genomic instability, recent investigation on its origin and final consequences reveal that the abnormal DNA metabolism in MN is a driver force for some types of catastrophic genomic rearrangements, accelerating dramatic genetic variation of cancer cells.

METHODS

We used Indirect Immunofluorescent staining to visualize micronuclei and activation of DNA repair factors in ovarian cancer cell lines and biopsies.

RESULTS

We show that ovarian cancer cells are disposed to form micronuclei upon genotoxic insults. Double strand DNA breaks (DSBs)-triggered insurgence of micronuclei is associated with unrepaired chromosomes passing through mitosis. According to their morphology and DNA staining, micronuclei compartments are divided into early and late stages that can be further characterized by differential staining of γH2AX and 53BP1. We also show that MN compartments do not halt controlled DNA metabolism as sequestered nuclear repair factors are enriched at DNA breaks in MN compartments and efficiently process DNA ends to generate single-stranded DNA (ssDNA) structures. Interestingly, unknown factors are required for DNA end processing in MN in addition to the nuclear resection machinery. Finally, these hallmarks of micronuclei evolution depicted in cell culture were recapitulated in different stages of ovarian cancer biopsies.

CONCLUSIONS

In aggregate, our findings demonstrate that ovarian cancer cells are inclined to form micronuclei that undergo robust DNA metabolism and generate ssDNA structures, potentially destabilizing genomic structures and triggering genetic variation.

Genetic Evidence for Early Peritoneal Spreading in Pelvic High-Grade Serous Cancer

Background

Most pelvic high-grade serous (HGS) carcinomas have been proposed to arise from tubal primaries that progress rapidly to advanced disease. However, the temporal sequence of ovarian and peritoneal metastases is not well characterized.

Methods

To establish the sequence of metastases, phylogenetic relationships among the ovarian and peritoneal carcinomas were determined from single-nucleotide variations (SNVs) in nine tumor regions from each patient with pelvic HGS carcinomas. Somatic SNVs from each tumor sample were used to reconstruct phylogenies of samples from each patient. Variant allele frequencies were used to reconstruct subclone phylogenies in each tumor sample.

Results

We show that pelvic HGS carcinomas are highly heterogeneous, only sharing less than 4% of somatic SNVs among all nine carcinoma implants in one patient. TP53 mutations are found in all nine carcinoma implants in each patient. The phylogenetic analyses reveal that peritoneal metastases arose from early branching events that preceded branching events for ovarian carcinomas in some patients. Finally, subclone phylogenies indicate the presence of multiple subclones at each tumor implant and early tumor clones in peritoneal implants.

Conclusion

The genetic evidence that peritoneal implants arose before or concurrently with ovarian implants is consistent with the emerging concept of the extra-ovarian origin of pelvic HGS cancer. Our results challenge the concept of stepwise spatial progression from the fallopian primary to ovarian carcinomas to peritoneal dissemination and suggest an alternative progression model where peritoneal spreading of early clones occurs before or in parallel with ovarian metastases.

Astragalus polysaccharides increase the sensitivity of SKOV3 cells to cisplatin

BACKGROUND

Multidrug resistance in malignant tumours hinders the treatment of tumours. Studies showed that astragalus polysaccharides (APS), one major active ingredient of astragalus, enhanced the sensitivity of non-small cell lung cancer and liver cancer cells to chemotherapeutic drug. However, the effect of APS on ovarian cancer is still unclear. In this study, we will examine the sensitizing effect of APS on SKOV3 cells to cisplatin and explore the possible mechanism.

METHODS

MTT assay was employed to examine the viability of SKOV3 after treatment with APS and cisplatin. The cell apoptosis rate was determined by flow cytometry. The expression of Bax, Bcl-2, Caspase-3, and c-Jun N-terminal kinases 1/2 (JNK1/2) was measured using Western blotting and RT-PCR.

RESULTS

APS synergistically promoted the inhibitory effect of cisplatin on SKOV3 cell viability. Flow cytometry showed that APS promoted cisplatin-induced apoptosis of SKOV3 cell lines. Further studies showed that APS down-regulated the expression of Bcl2, increased the expression of Bax and caspase 3 and activated JNK1/2 signalling pathway. The JNK inhibitors significantly rescued the proliferation inhibition induced by the drugs.

CONCLUSIONS

Astragalus polysaccharides increased the sensitivity of SKOV3 cells to cisplatin potentially by activating the JNK pathway. The apoptosis-related genes may contribute to the process. Thus, APS may be useful for the treatment of ovarian cancer as an enhancer of chemosensitivity.

Emerging Therapeutics to Overcome Chemoresistance in Epithelial Ovarian Cancer: A Mini-Review

Ovarian cancer is the fifth leading cause of cancer death among women and the most lethal gynecologic malignancy. One of the leading causes of death in high-grade serous ovarian cancer (HGSOC) is chemoresistant disease, which may present as intrinsic or acquired resistance to therapies. Here we discuss some of the known molecular mechanisms of chemoresistance that have been exhaustively investigated in chemoresistant ovarian cancer, including drug efflux pump multidrug resistance protein 1 (MDR1), the epithelial–mesenchymal transition, DNA damage and repair capacity. We also discuss novel therapeutics that may address some of the challenges in bringing approaches that target chemoresistant processes from bench to bedside. Some of these new therapies include novel drug delivery systems, targets that may halt adaptive changes in the tumor, exploitation of tumor mutations that leave cancer cells vulnerable to irreversible damage, and novel drugs that target ribosomal biogenesis, a process that may be uniquely different in cancer versus non-cancerous cells. Each of these approaches, or a combination of them, may provide a greater number of positive outcomes for a broader population of HGSOC patients.

Tissue and plasma levels of galectins in patients with high grade serous ovarian carcinoma as new predictive biomarkers

Galectins are moving closer to center stage in detecting glycosylation aberration in cancer cells. Here, we have investigated the expression of galectins in ovarian cancer (OC) and examined their potential as biomarkers in tissues and blood plasma samples of high grade serous ovarian carcinoma (HGSC) patients. In tissues, we found that increased protein expression of stromal gal-1 and epithelial gal-8/9 was associated with a poor response to treatment of HGSC patients. Gal-8/9 were both independent predictors of chemoresistance and overall survival (OS), respectively. This galectin signature increased the predictive value of the cancer antigen 125 (CA125) on 5-year disease-free survival (DFS), post-chemotherapy treatment and 5-year OS. In CA125^LOW patients, epithelial gal-9 was associated with a lower 5-year OS while stromal gal-1 and epithelial gal-8 were both associated with a lower 5-year DFS. Such negative predictive value of gal-8 and gal-9 was also found using plasma samples. In both cases, high plasma levels of gal-8 and gal-9 was associated with a lower OS and DFS. Overall, these data suggest that galectins may be promising biomarkers to identify subgroups of HGSC patients with poorer prognosis. Our study also contributes to better define the heterogeneity of the disease.

Mitochondrial mRNA transcripts predict overall survival, tumor recurrence and progression in serous ovarian cancer: Companion diagnostics for cancer therapy

Here, we performed a systematic analysis to discover new biomarkers of overall survival and tumor progression in ovarian cancer patients. More specifically, we determined whether nuclear-encoded mitochondrial genes related to mitochondrial biogenesis and function are effective in predicting clinical outcome in ovarian cancer. As a consequence, we are able to provide in silico validation of the prognostic value of these mitochondrial markers, in a well-defined population of ovarian cancer patients. Towards this end, we used a group of N=111 ovarian cancer patients (serous type; stage III), with optimal de-bulking. Importantly, in this group of cancer patients, CA125 and PCNA (conventional markers) were associated with poor overall survival, as would be expected. Using this approach, we identified >100 new individual mitochondrial gene probes that effectively predicted significantly reduced overall survival, with hazard-ratios (HR) of up to 3.68 (p < 9.8e-05). These mitochondrial mRNA transcripts included membrane proteins, chaperones, anti-oxidant enzymes, as well as mitochondrial ribosomal proteins (MRPs) and key members of the OXPHOS (I-V) complexes. Based on this bioinformatics analysis and in silico validation, we conclude that mitochondrial biogenesis and OXPHOS should both be considered as new therapeutic targets, for the more effective treatment of human ovarian cancers. The mitochondrial biomarkers that we have identified could also be employed as new companion diagnostics to assist oncologists in: i) more accurately predicting clinical outcomes and ii) improving the response to therapy, in ovarian cancer patients.

The enigmatic role of RUNX1 in female-related cancers - current knowledge & future perspectives

Historically associated with the aetiology of human leukaemia, the runt-related transcription factor 1 (RUNX1) gene has in recent years reared its head in an assortment of epithelial cancers. This review discusses the state-of-the-art knowledge of the enigmatic role played by RUNX1 in female-related cancers of the breast, the uterus and the ovary. The weight of evidence accumulated so far is indicative of a very context-dependent role, as either an oncogene or a tumour suppressor. This is corroborated by high-throughput sequencing endeavours which report different genetic alterations affecting the gene, including amplification, deep deletion and mutations. Herein, we attempt to dissect that contextual role by firstly giving an overview of what is currently known about RUNX1 function in these specific tumour types, and secondly by delving into connections between this transcription factor and the physiology of these female tissues. In doing so, RUNX1 emerges not only as a gene involved in female sex development but also as a crucial mediator of female hormone signalling. In view of RUNX1 now being listed as a driver gene, we believe that greater knowledge of the mechanisms underlying its functional dualism in epithelial cancers is worthy of further investigation.