Minireview: human ovarian cancer: biology, current management, and paths to personalizing therapy

Soluble heat-shock protein 27 in blood serum is a non-invasive prognostic biomarker for ovarian cancer

OBJECTIVES

Ovarian cancer (OC) is the leading cause of death in gynecological oncology, primarily caused by limited prognostic and therapeutic options. The heat shock protein 27 (HSP27) is recognized as a prominent factor in OC, playing a pivotal role in cancer progression machinery such as treatment resistance. Thus, HSP27 may represent an appropriate biomarker for OC diagnosis, prognosis, and therapy response.

MATERIALS & METHODS

Extracellular HSP27 levels were measured by enzyme-linked immunosorbent assay (ELISA) in serum samples of OC patients (n = 242) and compared to a non-malignant control group without any history of cancer (n = 200). Correlations between serum levels of HSP27 and clinical pathological parameters were analyzed by bivariate analysis. Survival analyses were carried out by Kaplan-Meier test.

RESULTS

This study demonstrated that protein levels of HSP27 are comparable in the blood serum of healthy women and OC patients. However, HSP27 levels are significantly correlated with the volume of ascites, residual tumor mass, and age at first diagnosis in OC patients. Notably, elevated levels of HSP27 demonstrate significantly higher overall survival.

CONCLUSION

Taken together, our findings demonstrate that high levels of circulating HSP27 in serum are associated with improved overall survival of OC patients. Even though functionality of secreted HSP27 is still unclear, serum levels of HSP27 represent a putative non-invasive prognostic biomarker candidate for OC progression.

Fibroblast growth factor receptor signaling as therapeutic targets in female reproductive system cancers

Ovarian cancer, cervical cancer and endometrial cancer are three relatively common malignant cancers of the female reproductive system. Despite improvements in female genital tract cancer detection and development of new therapeutic approaches, there are still poor prognoses and some do not respond to therapeutic patterns, displaying low survival and high frequency of recurrence. In an era of personalized medicine, novel therapeutic approaches with greater efficacy for these cancers represent an unmet need. One of the actionable signaling pathways is the fibroblast growth factor receptor (FGFR) signaling pathway. Several mutations and alterations in FGF/FGFR family members have been reported in human cancers. FGF/FGFR signaling pathway has become a new target for cancer therapy. This review will summarize the role of FGFR pathway and the genetic alterations of the FGF/FGFR related to female reproductive system cancer. We will describe the available inhibitors of FGFR pathway for potential treatment of female reproductive system cancer. Furthermore, we will discuss FGFR-targeted therapies under clinical development for treatment of female reproductive system cancer.

The Role of GDF15 in Regulating the Canonical Pathways of the Tumor Microenvironment in Wild-Type p53 Ovarian Tumor and Its Response to Chemotherapy

Simple Summary

Patients with wild-type p53 ovarian cancer appear to have a poorer survival rate than those with mutant p53 due to resistance to chemotherapy. The mechanism underlying this observation is not clearly understood. The aim of this study was to identify potential biomarkers regulated by p53 that conferred resistance using in vitro and in vivo studies. Growth differentiation factor 15 (GDF15) expression was demonstrated to be controlled by p53 in both ovarian cancer cell lines and orthotopic mouse models. The histological and RNAseq studies of the GDF15-knocked down, A2780 cell line-induced tumor revealed that the ratio and canonical pathways of stromal/tumor were modified by secretory GDF15.

Abstract

Background: The standard treatment of ovarian cancer is surgery followed by a chemotherapeutic combination consisting of a platinum agent, such as cisplatin and a taxane-like paclitaxel. We previously observed that patients with ovarian cancer wild-type for p53 had a poorer survival rate than did those with p53 mutations. Thus, a better understanding of the molecular changes of epithelial ovarian cancer cells with wild-type p53 in response to treatment with cisplatin could reveal novel mechanisms of chemoresistance. Methods: Gene expression profiling was performed on an ovarian cancer cell line A2780 with wild-type p53 treated with cisplatin. A gene encoding a secretory protein growth differentiation factor 15 (GDF15) was identified to be highly induced by cisplatin treatment in vitro. This was further validated in a panel of wild-type and mutant p53 ovarian cancer cell lines, as well as in mouse orthotopic models. The mouse tumor tissues were further analyzed by histology and RNA-seq. Results: GDF15 was identified as one of the highly induced genes by cisplatin or carboplatin in ovarian cancer cell lines with wild-type p53. The wild-type p53-induced expression of GDF15 and GDF15-confered chemotherapy resistance was further demonstrated in vitro and in vivo. This study also discovered that GDF15-knockdown (GDF15-KD) tumors had less stromal component and had different repertoires of activated and inhibited canonical pathways in the stromal cell and cancer cell components from that of the control tumors after cisplatin treatment. Conclusions: GDF15 expression from the wild-type p53 cancer cells can modulate the canonical pathways in the tumor microenvironment in response to cisplatin, which is a possible mechanism of chemoresistance.

Angiogenesis in gynecological cancers and the options for anti-angiogenesis therapy

Angiogenesis is required in cancer, including gynecological cancers, for the growth of primary tumors and secondary metastases. Development of anti-angiogenesis therapy in gynecological cancers and improvement of its efficacy have been a major focus of fundamental and clinical research. However, survival benefits of current anti-angiogenic agents, such as bevacizumab, in patients with gynecological cancer, are modest. Therefore, a better understanding of angiogenesis and the tumor microenvironment in gynecological cancers is urgently needed to develop more effective anti-angiogenic therapies, either or not in combination with other therapeutic approaches. We describe the molecular aspects of (tumor) blood vessel formation and the tumor microenvironment and provide an extensive clinical overview of current anti-angiogenic therapies for gynecological cancers. We discuss the different phenotypes of angiogenic endothelial cells as potential therapeutic targets, strategies aimed at intervention in their metabolism, and approaches targeting their (inflammatory) tumor microenvironment.

Synergistic Anti-Tumor Activity by Targeting Multiple Signaling Pathways in Ovarian Cancer

More effective therapy is needed to improve the survival of patients with advanced and recurrent ovarian cancer. Preclinical and early clinical studies with single molecular targeted agents have shown limited antitumor activity in ovarian cancer, likely due to compensation by alternative growth/survival pathways. An emerging strategy in overcoming resistance is to combine inhibitors targeting multiple pathways. In this study, we used a novel strategy of combining several FDA-approved targeted drugs, including sunitinib, dasatinib, and everolimus, in human ovarian cancers. Combination of the tyrosine kinase inhibitor sunitinib with the SRC inhibitor dasatinib showed synergistic anti-tumor activity in human ovarian cancer cells. The increased activity was associated with inhibition of the STAT3, SRC, and MAPK signaling pathways, but not AKT signaling. To inhibit the PI3K/AKT/mTOR pathway, we added the mTOR inhibitor everolimus, which further increased anti-tumor activity in cells. Combined treatment with sunitinib, dasatinib, and everolimus also resulted in greater inhibition of human ovarian tumor growth in mice. Furthermore, the triple combination also synergistically increased the anti-tumor activity of paclitaxel, both in vitro and in vivo. Taken together, our results demonstrate that simultaneous inhibition of several signaling pathways results in better anti-tumor activity compared to inhibiting any of these signaling pathways alone.

A Sandwich Nanostructure of Gold Nanoparticle Coated Reduced Graphene Oxide for Photoacoustic Imaging-Guided Photothermal Therapy in the Second NIR Window

We explore a sandwich-type gold nanoparticle coated reduced graphene oxide (rGO-AuNP) as an effective nanotheranostic platform for the second near-infrared (NIR-II) window photoacoustic (PA) imaging-guided photothermal therapy (PTT) in ovarian cancer. The PEG was loaded onto the AuNPs surface to increase the stability of nanostructure. The forming rGO-AuNPs- PEG revealed very strong SERS signal, NIR-II PA signal and high photothermal efficiency against tumor upon 1,061 nm laser irradiation. The prominent performance was attributed to the plasmonic coupling of AuNPs, and the enhanced response of rGO and the plasmonic AuNP. Thus, our study demonstrates that the rGO-AuNP nanocomposite could promise to be a potential photothermal agent and pave the way for the diagnosis and therapy of ovarian cancer in the future.

Photodynamic Therapy Using a New Folate Receptor-Targeted Photosensitizer on Peritoneal Ovarian Cancer Cells Induces the Release of Extracellular Vesicles with Immunoactivating Properties

Often discovered at an advanced stage, ovarian cancer progresses to peritoneal carcinoma, which corresponds to the invasion of the serosa by multiple tumor implants. The current treatment is based on the combination of chemotherapy and tumor cytoreduction surgery. Despite the progress and standardization of surgical techniques combined with effective chemotherapy, post-treatment recurrences affect more than 60% of women in remission. Photodynamic therapy (PDT) has been particularly indicated for the treatment of superficial lesions on large surfaces and appears to be a relevant candidate for the treatment of microscopic intraperitoneal lesions and non-visible lesions. However, the impact of this therapy on immune cells remains unclear. Hence, the objective of this study is to validate the efficacy of a new photosensitizer [pyropheophorbide a-polyethylene glycol-folic acid (PS)] on human ovarian cancer cells and to assess the impact of the secretome of PDT-treated cells on human peripheral blood mononuclear cells (PBMC). We show that PS, upon illumination, can induce cell death of different ovarian tumor cells. Furthermore, PDT using this new PS seems to favor activation of the immune response by inducing the secretion of effective cytokines and inhibiting the pro-inflammatory and immunosuppressive ones, as well as releasing extracellular vesicles (EVs) prone to activating immune cells. Finally, we show that PDT can activate CD4+ and CD8+ T cells, resulting in a potential immunostimulating process. The results of this pilot study therefore indicate that PS-PDT treatment may not only be effective in rapidly and directly destroying target tumor cells but also promote the activation of an effective immune response; notably, by EVs. These data thus open up good prospects for the treatment of micrometastases of intraperitoneal ovarian carcinosis which are currently inoperable.

Bioinformatic profiling identifies a platinum-resistant-related risk signature for ovarian cancer

Most high-grade serous ovarian cancer (HGSOC) patients develop resistance to platinum-based chemotherapy and recur. Many biomarkers related to the survival and prognosis of drug-resistant patients have been delved by mining databases; however, the prediction effect of single-gene biomarker is not specific and sensitive enough. The present study aimed to develop a novel prognostic gene signature of platinum-based resistance for patients with HGSOC. The gene expression profiles were obtained from Gene Expression Omnibus and The Cancer Genome Atlas database. A total of 269 differentially expressed genes (DEGs) associated with platinum resistance were identified (P < .05, fold change >1.5). Functional analysis revealed that these DEGs were mainly involved in apoptosis process, PI3K-Akt pathway. Furthermore, we established a set of seven-gene signature that was significantly associated with overall survival (OS) in the test series. Compared with the low-risk score group, patients with a high-risk score suffered poorer OS (P < .001). The area under the curve (AUC) was found to be 0.710, which means the risk score had a certain accuracy on predicting OS in HGSOC (AUC > 0.7). Surprisingly, the risk score was identified as an independent prognostic indicator for HGSOC (P < .001). Subgroup analyses suggested that the risk score had a greater prognostic value for patients with grade 3-4, stage III-IV, venous invasion and objective response. In conclusion, we developed a seven-gene signature relating to platinum resistance, which can predict survival for HGSOC and provide novel insights into understanding of platinum resistance mechanisms and identification of HGSOC patients with poor prognosis.

miR-205-3p Functions as a Tumor Suppressor in Ovarian Carcinoma

Ovarian cancer (OC) represents the most lethal form of gynaecologic cancers in developed countries. To develop a better therapeutic against OC, characterizing new classes of molecular regulators such as microRNAs (miRNAs) involved in OC tumorigenesis becomes immensely important. We used human OC cell lines to study the expression pattern of miRNA-205-3p. We then employed miRNA-205-3p mimic and inhibitor to elucidate its functional role in OC cells. Downstream target of miRNA-205-3p was characterized in OC cells with luciferase gene reporter assay and Western blotting. Its functional role in OC was also investigated with the siRNA approach. Lastly, we assessed the expression change of miRNA-205-3p and its newly identified target in human OC tissues. miR-205-3p was downregulated in five human OC lines tested. Over-expressing miR-205-3p reduced OC cell proliferation and migration. MAPK10 was identified as a direct target of miR-205-3p. Knocking down MAPK10 suppressed OC cell growth and migration. In contrast, knocking down miR-205-3p promoted clonogenicity of primary ovary cells. In clinical samples, miR-205-3p and MAPK10 expressed inversely in accordance with their expression patterns in OC cells. miR-205-3p was shown as a novel tumor suppressor in OC via inhibiting the MAPK10 pathway. This new finding may inspire new personalized treatment for OC.

MicroRNAs in ovarian cancer and recent advances in the development of microRNA-based biosensors

Ovarian cancer is the most aggressive of all gynaecological malignancies and is the leading cause of cancer-associated mortality worldwide.

Long Non-Coding RNA LINC00511 Mediates the Effects of ESR1 on Proliferation and Invasion of Ovarian Cancer Through miR-424-5p and miR-370-5p

Introduction

Estrogen receptor 1 (ESR1) plays an important role in the pathological events of ovarian cancer (OV), but the underlying mechanism is not completely understood. Using bioinformatics analysis, we found that ESR1 is involved in the regulation of some lncRNAs that are highly expressed in ovarian cancer. The lncRNAs might mediate the roles of ESR1 in OV occurrence and progression.

Methods

This study measured the expression of the lncRNAs in OV cell lines using qRT-PCR. Some of the lncRNAs were silenced or overexpressed to determine their effects on the growth and invasion of CAOV3 cells with the stimulation of 17 beta-estradiol or not.

Results

ESR1-expressing OV cells (CAOV3 cells) shows higher LINC00511 and RP11-166P13.3 expression than the ESR1-losing OV cells (UWB1.289 cells). Depletion of the two lncRNAs enhanced cell viability and invasion and decreased apoptosis rate. In these respects, effects of LINC00511 were more remarkable than that those of RP11-166P13.3. Treatment with 17 beta-estradiol to stimulate ESR1 increased LINC00511 expression, while ESR1 inhibitor Fulvestrant decreased LINC00511 expression. FISH assay confirmed that LINC00511 is present in the cytoplasm and nucleus. Bioinformatics analysis revealed the interaction of LINC00511 with miR-424-5p and miR-370-5p, which was further identified by RNA-pull down assay. As indicated by RIP assay, silencing LINC00511 increased the interaction between Ago protein and these two miRNAs.

Discussion

Our study showed that ESR1-induced upregulation of LINC00511 promoted proliferation and invasion of CAOV3 cells probably through sponging miR-424-5p and miR-370-5p.

Exploring receptor tyrosine kinases-inhibitors in Cancer treatments

Background

Receptor tyrosine kinases (RTKs) are signaling enzymes responsible for the transfer of Adenosine triphosphate (ATP) γ-phosphate to the tyrosine residues substrates. RTKs demonstrate essential roles in cellular growth, metabolism, differentiation, and motility. Anomalous expression of RTK customarily leads to cell growth dysfunction, which is connected to tumor takeover, angiogenesis, and metastasis. Understanding the structure, mechanisms of adaptive and acquired resistance, optimizing inhibition of RTKs, and eradicating cum minimizing the havocs of quiescence cancer cells is paramount.

MainText

Tyrosine kinase inhibitors (TKIs) vie with RTKs ATP-binding site for ATP and hitherto reduce tyrosine kinase phosphorylation, thus hampering the growth of cancer cells. TKIs can either be monoclonal antibodies that compete for the receptor’s extracellular domain or small molecules that inhibit the tyrosine kinase domain and prevent conformational changes that activate RTKs. Progression of cancer is related to aberrant activation of RTKs due to due to mutation, excessive expression, or autocrine stimulation.

Conclusions

Understanding the modes of inhibition and structures of RTKs is germane to the design of novel and potent TKIs. This review shed light on the structures of tyrosine kinases, receptor tyrosine kinases, tyrosine kinase inhibitors, minimizing imatinib associated toxicities, optimization of tyrosine kinase inhibition in curtailing quiescence in cancer cells and the prospects of receptor tyrosine kinase based treatments.

Clinical Utility of Real-Time Targeted Molecular Profiling in the Clinical Management of Ovarian Cancer: The ALLOCATE Study

PURPOSE

The ALLOCATE study was designed as a pilot to demonstrate the feasibility and clinical utility of real-time targeted molecular profiling of patients with recurrent or advanced ovarian cancer for identification of potential targeted therapies.

PATIENTS AND METHODS

A total of 113 patients with ovarian cancer of varying histologies were recruited from two tertiary hospitals, with 99 patient cases suitable for prospective analysis. Targeted molecular and methylation profiling of fresh biopsy and archived tumor samples were performed by screening for mutations or copy-number variations in 44 genes and for promoter methylation of BRCA1 and RAD51C.

RESULTS

Somatic genomic or methylation events were identified in 85% of all patient cases, with potentially actionable events with defined targeted therapies (including four resistance events) detected in 60% of all patient cases. On the basis of these findings, six patients received molecularly guided therapy, three patients had unsuspected germline cancer–associated BRCA1/ 2 mutations and were referred for genetic counseling, and two intermediate differentiated (grade 2) serous ovarian carcinomas were reclassified as low grade, leading to changes in clinical management. Additionally, secondary reversion mutations in BRCA1/ 2 were identified in fresh biopsy samples of two patients, consistent with clinical platinum/poly (ADP-ribose) polymerase inhibitor resistance. Timely reporting of results if molecular testing is done at disease recurrence, as well as early referral for patients with platinum-resistant cancers, were identified as factors that could improve the clinical utility of molecular profiling.

CONCLUSION

ALLOCATE molecular profiling identified known genomic and methylation alterations of the different ovarian cancer subtypes and was deemed feasible and useful in routine clinical practice. Better patient selection and access to a wider range of targeted therapies or clinical trials will further enhance the clinical utility of molecular profiling.

Association between EPHX1 polymorphism rs1051740 and the risk of ovarian cancer: a meta-analysis

Objective: We carried out a meta-analysis of case-control studies to determine whether epoxide hydrolase 1 (EPHX1) gene polymorphism rs1051740 was related to the risk of ovarian cancer. Methods: Electronic databases were searched for relevant articles published in English or Chinese language. We calculated crude odds ratios (ORs) with their 95% confidence intervals (95% CIs) to assess the relationship of EPHX1 polymorphism rs1051740 with ovarian cancer risk. In addition, subgroup analyses were also conducted based on ethnicity and control source. Between-study heterogeneity was inspected with Q test and I² statistic. Results: Five eligible studies with a total of 1919 ovarian cancer patients and 1829 controls were ultimately included in the present meta-analysis. Overall results demonstrated that the association between EPHX1 polymorphism rs1051740 and ovarian cancer risk had no statistical significance either in total analysis or in subgroup analyses by ethnicity and source of control. Conclusion: EPHX1 polymorphism rs1051740 may have no independent effect on ovarian cancer susceptibility.

Heat Shock Proteins and Ovarian Cancer: Important Roles and Therapeutic Opportunities

Ovarian cancer is a serious cause of death in gynecological oncology. Delayed diagnosis and poor survival rates associated with late stages of the disease are major obstacles against treatment efforts. Heat shock proteins (HSPs) are stress responsive molecules known to be crucial in many cancer types including ovarian cancer. Clusterin (CLU), a unique chaperone protein with analogous oncogenic criteria to HSPs, has also been proven to confer resistance to anti-cancer drugs. Indeed, these chaperone molecules have been implicated in diagnosis, prognosis, metastasis and aggressiveness of various cancers. However, relative to other cancers, there is limited body of knowledge about the molecular roles of these chaperones in ovarian cancer. In the current review, we shed light on the diverse roles of HSPs as well as related chaperone proteins like CLU in the pathogenesis of ovarian cancer and elucidate their potential as effective drug targets.

Ultrasound screening of ovarian cancer

Ovarian cancer has a high mortality rate. The most common serous type spreads rapidly throughout the peritoneal cavity when 5-year survival is 10%. If diagnosed in earlier stages where the cancer is still confined to the ovary, this survival rate is about 90%. This is the reason to be interested in screening at earlier stages in the average-risk general population. Thus, annual transvaginal ultrasound (TVS) alone or as a multimodal screening test following serum carbohydrate antigen 125 (CA125) has been investigated. Ultrasound lacks sensitivity and specificity; new contrast-enhanced approaches might improve these. When the serum marker is combined with ultrasound and interpreted by a rise in the level rather than by a fixed cut-off, improved sensitivity and specificity and a late but not significant reduction in mortality are observed. Further investigations could highlight the interest of a shorter than annual screening, of a long-term follow-up and new contrast-enhanced ultrasound techniques.

MicroRNA biogenesis, gene silencing mechanisms and role in breast, ovarian and prostate cancer

Micro-ribonucleic acids (miRNAs) are important class of short regulatory RNA molecules involved in regulation of several essential biological processes. In addition to Dicer and Drosha, over the past few years several other gene products are discovered that regulates miRNA biogenesis pathways. Similarly, various models of molecular mechanisms underlying miRNA mediated gene silencing have been uncovered through which miRNA contribute in diverse physiological and pathological processes. Dysregulated miRNA expression has been reported in many cancers manifesting tumor suppressive or oncogenic role. In this review, critical overview of recent findings in miRNA biogenesis, silencing mechanisms and specifically the role of miRNA in breast, ovarian and prostate cancer will be described. Recent advancements in miRNA research summarized in this review will enhance the molecular understanding of miRNA biogenesis and mechanism of action. Also, role of miRNAs in pathogenesis of breast, ovarian and prostate cancer will provide the insights for the use of miRNAs as biomarker or therapeutic agents for the cancers.

Dyadic coping mediates the effects of attachment on quality of life among couples facing ovarian cancer

Cancer is an interpersonal stressor affecting both patient and spouse. To examine the pathways that insecure adult attachment can impact health outcomes by way of dyadic processes, this cross-sectional study used the actor-partner interdependence mediation model to examine whether common dyadic coping (CDC) mediated the associations between attachment and quality of life (QOL). Couples (N = 106) facing ovarian cancer were recruited from a comprehensive cancer center and completed self-report questionnaires. Results indicated that worse social and functional QOL were associated with both one's own and one's partner's greater insecure attachment, by way of one's own use of less CDC. Unexpectedly, greater CDC reported by one's partner was associated with one's own lower functional QOL. Although CDC has beneficial effects on QOL, CDC may also be experienced as draining. Effects of adult attachment on dyadic coping are a significant contributor to subjective health outcomes among couples facing ovarian cancer.

p53-Bad: A Novel Tumor Suppressor/Proapoptotic Factor Hybrid Directed to the Mitochondria for Ovarian Cancer Gene Therapy

Clinical trials involving p53 gene therapy for ovarian cancer failed due to the dominant negative inhibition of wild-type p53 and multiple genetic aberrations in ovarian cancer. To overcome this problem, we have designed a more potent chimeric gene fusion, called p53-Bad, that combines p53 with the mitochondrial pro-apoptotic factor Bad. Unlike wild-type p53, which acts as a nuclear transcription factor, this novel p53-Bad construct has multiple unique mechanisms of action including a direct and rapid apoptotic effect at the mitochondria. The mitochondrial localization, transcription activity, and apoptotic activity of the constructs were tested. The results suggest that p53 can be effectively targeted to the mitochondria by controlling the phosphorylation of pro-apoptotic Bad, which can only localize to the mitochondria when Ser-112 and Ser-136 of Bad are unphosphorylated. By introducing S112A and S136A mutations, p53-Bad fusion cannot be phosphorylated at these two sites and always localizes to the mitochondria. p53-Bad constructs also have superior activity over p53 and Bad alone. The apoptotic activity is consistent in many ovarian cancer cell lines regardless of the endogenous p53 status. Both p53 and the BH3 domain of Bad contribute to the superior activity of p53-Bad. Our data suggests that p53-Bad fusions are capable of inducing apoptosis and should be further pursued for gene therapy for ovarian cancer.

Novel Approaches to Ovarian Cancer Screening

PURPOSE OF REVIEW

Both conventional and novel approaches to early detection of ovarian cancer are reviewed in the context of new developments in our understanding of ovarian cancer biology.

RECENT FINDINGS

While CA125 as a single value lacks adequate specificity or sensitivity for screening, large studies have shown that a 2-stage strategy which tracks CA125 change over time and prompts transvaginal ultrasound (TVS) for a small subset of women with abnormally rising biomarker values achieves adequate specificity and detects a higher fraction of early-stage disease. Sensitivity could clearly be improved in both blood tests and in imaging. Metastasis can occur from ovarian cancers too small to increase blood levels of protein antigens and a significant fraction of ovarian cancers arise from the fimbriae of fallopian tubes that cannot be imaged with TVS. Autoantibodies, miRNA, ctDNA, DNA methylation in blood, and cervical mucus might improve sensitivity of the initial phase and magnetic relaxometry and autofluorescence could improve imaging in the second phase. Enhancing the sensitivity of two-stage strategies for early detection could reduce mortality from ovarian cancer.

Genetic Profiles Associated with Chemoresistance in Patient-Derived Xenograft Models of Ovarian Cancer

PURPOSE

Recurrence and chemoresistance (CR) are the leading causes of death in patients with high-grade serous carcinoma (HGSC) of the ovary. The aim of this study was to identify genetic changes associated with CR mechanisms using a patient-derived xenograft (PDX) mouse model and genetic sequencing.

MATERIALS AND METHODS

To generate a CR HGSC PDX tumor, mice bearing subcutaneously implanted HGSC PDX tumors were treated with paclitaxel and carboplatin. We compared gene expression and mutations between chemosensitive (CS) and CR PDX tumors with whole exome and RNA sequencing and selected candidate genes. Correlations between candidate gene expression and clinicopathological variables were explored using the Cancer Genome Atlas (TCGA) database and the Human Protein Atlas (THPA).

RESULTS

Three CR and four CS HGSC PDX tumor models were successfully established. RNA sequencing analysis of the PDX tumors revealed that 146 genes were significantly up-regulated and 54 genes down-regulated in the CR group compared with the CS group. Whole exome sequencing analysis showed 39 mutation sites were identified which only occurred in CR group. Differential expression of SAP25, HLA-DPA1, AKT3, and PIK3R5 genes and mutation of TMEM205 and POLR2A may have important functions in the progression of ovarian cancer chemoresistance. According to TCGA data analysis, patients with high HLA-DPA1 expression were more resistant to initial chemotherapy (p=0.030; odds ratio, 1.845).

CONCLUSION

We successfully established CR ovarian cancer PDX mouse models. PDX-based genetic profiling study could be used to select some candidate genes that could be targeted to overcome chemoresistance of ovarian cancer.

Adipose Tissue, Obesity and Adiponectin: Role in Endocrine Cancer Risk

Adipose tissue has been recognized as a complex organ with endocrine and metabolic roles. The excess of fat mass, as occurs during overweight and obesity states, alters the regulation of adipose tissue, contributing to the development of obesity-related disorders. In this regard, many epidemiological studies shown an association between obesity and numerous types of malignancies, comprising those linked to the endocrine system (e.g., breast, endometrial, ovarian, thyroid and prostate cancers). Multiple factors may contribute to this phenomenon, such as hyperinsulinemia, dyslipidemia, oxidative stress, inflammation, abnormal adipokines secretion and metabolism. Among adipokines, growing interest has been placed in recent years on adiponectin (APN) and on its role in carcinogenesis. APN is secreted by adipose tissue and exerts both anti-inflammatory and anti-proliferative actions. It has been demonstrated that APN is drastically decreased in obese individuals and that it can play a crucial role in tumor growth. Although literature data on the impact of APN on carcinogenesis are sometimes conflicting, the most accredited hypothesis is that it has a protective action, preventing cancer development and progression. The aim of the present review is to summarize the currently available evidence on the involvement of APN and its signaling in the etiology of cancer, focusing on endocrine malignancies.

In Utero Exposure to Benzo[a]pyrene Induces Ovarian Mutations at Doses That Deplete Ovarian Follicles in Mice

Polycyclic aromatic hydrocarbons like benzo[a]pyrene (BaP) are ubiquitous environmental contaminants formed during incomplete combustion of organic materials. Our prior work showed that transplacental exposure to BaP depletes ovarian follicles and increases prevalence of epithelial ovarian tumors later in life. We used the MutaMouse transgenic rodent model to address the hypothesis that ovarian mutations play a role in tumorigenesis caused by prenatal exposure to BaP. Pregnant MutaMouse females were treated with 0, 10, 20, or 40 mg/(kg day) BaP orally on gestational days 7-16, covering critical windows of ovarian development. Female offspring were euthanized at 10 weeks of age; some ovaries with oviducts were processed for follicle counting; other ovaries/oviducts and bone marrow were processed for determination of lacZ mutant frequency (MF). Mutant plaques were pooled within dose groups and sequenced to determine the mutation spectrum. BaP exposure caused highly significant dose-related decreases in ovarian follicles and increases in ovarian/oviductal and bone marrow mutant frequencies at all doses. Absence of follicles, cell packets, and epithelial tubular structures were observed with 20 and 40 mg/(kg day) BaP. Depletion of ovarian germ cells was inversely associated with ovarian MF. BaP induced primarily G > T and G > C transversions and deletions in ovaries/oviducts and bone marrow cells and produced a mutation signature highly consistent with that of tobacco smoking in human cancers. Overall, our results show that prenatal BaP exposure significantly depletes ovarian germ cells, causes histopathological abnormalities, and increases the burden of ovarian/oviductal mutations, which may be involved in pathogenesis of epithelial ovarian tumors. Environ. Mol. Mutagen. 60:410-420, 2019. © 2018 Her Majesty the Queen in Right of Canada.

Ovarian cancer relapse: From the latest scientific evidence to the best practice

Ovarian cancer (OC) is the fifth most common cause of cancer death in women worldwide. Despite treatment options have continued to improve in recent years, the recurrence rate is still high; in fact around 80% of patients relapses within 18 months. Recently, the scientific landscape is agree in asserting that the ovarian cancer is not a single disease but the outcome of patients depends from the molecular and biological characterization of tumor tissue. In this scenario, molecular targeted therapy given alone or in combination with chemotherapy is showing significant results. We review the different options for the treatment of ovarian cancer recurrence, including the role of surgery, in order to try outlining a possible treatment algorithm evaluating the recent scientific literature and the most important trials.

The human amniotic fluid mesenchymal stem cells therapy on, SKOV3, ovarian cancer cell line

Purpose

One of the most common malignancies peculiar to female health with few symptoms, low response to therapy, difficult diagnosis, frequent relapse, and high mortality, is ovarian cancer. Thus, our experiment, using Human amniotic fluid mesenchymal stem cells (hAFMSCs) as a therapeutic tool, aims to find an efficient treatment approach for patients suffering from SKOV3 ovarian cancer.

Material & Methods

In this study, we obtained 5 ml amniotic fluid from 16–20 week pregnant women who underwent amniocentesis for routine prenatal diagnosis by karyotyping in Al‐Zahra Hospital of Tabriz University of Medical Sciences, Iran. Using trans wells in 24 wells plate, hAFMSCs were isolated from all samples, co‐cultured with SKOV3 ovarian cancer cell line, and characterized via flow cytometry and RT‐PCR. Human skin fibroblast cells (HSFCs) were isolated and used as a negative control. SKOV3 and HSFCs' viability after 5 days was evaluated by MTT assay. Cell cycle and apoptotic genes were analyzed by real‐time PCR.

Results

We successfully isolated and characterized hAFMSCs through it positivity for CD44 and CD90 specific mesenchymal stem cell markers and negativity for CD31 and CD45. Oct4 and NANOG were evaluated by RT‐PCR as pluripotency markers, and visualized on 2% gel electrophoresis. We established hAFMS cell lines after 5 days of co‐culturing the SKOV3 cells, viability was decreased; however, HSFCs did not show toxicity by MTT assay. The genes indicated upregulation and high expression by a real‐time PCR.

Conclusions

Our findings showed that hAFMSCs have natural tumor tropism, and can release soluble factors in a cell culture, which cause an efficient anticancer effect. Thus, we can use hAFMSCs for complete anticancer therapy on SKOV3 cell line at cell culture condition and possibly in vivo in the near future.

Estrogen-independent role of ERα in ovarian cancer progression induced by leptin/Ob-Rb axis

Leptin induces ovarian cancer cell invasion via overexpression of MMP7, MMP9, and upA. In addition, the key role of ERα in leptin-increased cell growth was indicated. However, the influence of ER on leptin-mediated cell invasion remains still unknown. The present study was designed to evaluate the E2-independent effect of ERα/β on leptin-mediated cell invasion and cell proliferation in ovarian cancer. We utilized SKOV3 cancer (expressing OB-Rb and ERα/β, insensitive to estrogen) and OVCAR3 (expressing OB-Rb) cell lines to show the involvement of ER in leptin-mediated effects in an E2-independent manner. MTT, BrdU, and BD matrigel invasion assays were applied to analyze cell growth, proliferation, and invasion. The siRNA approach was used to confirm the role of ERα/β in leptin effects. Moreover, western blotting and Real-time PCR were employed to detect the OB-Rb, ER, MMP9/7, and upA proteins and mRNAs. Leptin, in the absence of E2, increased ERα expression in SKOV3 cells, which was attenuated using knockdown of OB-Rb gene by siRNA. The effect of leptin on the cell growth was promoted in the presence of PPT, but not in the presence of DNP and E2, which was lost when OB-Rb siRNA was transfected. Furthermore, ERα gene silencing and/or pre-incubation with ER antagonist (ICI 182,780, 10 nM) significantly reduced cell invasion and MMP9 expression stimulated by leptin. In conclusion, our findings demonstrated that ERα, but not ERβ, is involved in leptin-induced ovarian cancer in an E2-independent manner, providing new evidence for cancer progression in obesity-associated ovarian cancer.

The Emerging Role of Adiponectin in Female Malignancies

Obesity, characterized by excess body weight, is now accepted as a hazardous health condition and an oncogenic factor. In different epidemiological studies obesity has been described as a risk factor in several malignancies. Some biological mechanisms that orchestrate obesity-cancer interaction have been discovered, although others are still not completely understood. The unbalanced secretion of biomolecules, called "adipokines", released by adipocytes strongly influences obesity-related cancer development. Among these adipokines, adiponectin exerts a critical role. Physiologically adiponectin governs glucose levels and lipid metabolism and is fundamental in the reproductive system. Low adiponectin circulating levels have been found in obese patients, in which its protective effects were lost. In this review, we summarize the epidemiological, in vivo and in vitro data in order to highlight how adiponectin may affect obesity-associated female cancers.

The contribution and perspectives of proteomics to uncover ovarian cancer tumor markers

Despite all the advances in understanding the mechanisms involved in ovarian cancer (OC) development, many aspects still need to be unraveled and understood. Tumor markers (TMs) are of special interest in this disease. Some aspects of clinical management of OC might be improved by the use of validated TMs, such as differentiating subtypes, defining the most appropriate treatment, monitoring the course of the disease, or predicting clinical outcome. The Food and Drug Administration (FDA) has approved a few TMs for OC: CA125 (cancer antigen 125; monitoring), HE4 (Human epididymis protein; monitoring), ROMA (Risk Of Malignancy Algorithm; HE4+CA125; prediction of malignancy) and OVA1 (Vermillion's first-generation Multivariate Index Assay [MIA]; prediction of malignancy). Proteomics can help advance the research in the field of TMs for OC. A variety of biological materials are being used in proteomic analysis, among them tumor tissues, interstitial fluids, tumor fluids, ascites, plasma, and ovarian cancer cell lines. However, the discovery and validation of new TMs for OC is still very challenging. The enormous heterogeneity of histological types of samples and the individual variability of patients (lifestyle, comorbidities, drug use, and family history) are difficult to overcome in research protocols. In this work, we sought to gather relevant information regarding TMs, OC, biological samples for proteomic analysis, as well as markers and algorithms approved by the FDA for use in clinical routine.

Mechanisms of Adiponectin Action in Fertility: An Overview from Gametogenesis to Gestation in Humans and Animal Models in Normal and Pathological Conditions

Adiponectin is the most abundant plasma adipokine. It mainly derives from white adipose tissue and plays a key role in the control of energy metabolism thanks to its insulin-sensitising, anti-inflammatory, and antiatherogenic properties. In vitro and in vivo evidence shows that adiponectin could also be one of the hormones controlling the interaction between energy balance and fertility in several species, including humans. Indeed, its two receptors—AdipoR1 and AdipoR2—are expressed in hypothalamic–pituitary–gonadal axis and their activation regulates Kiss, GnRH and gonadotropin expression and/or secretion. In male gonads, adiponectin modulates several functions of both somatic and germ cells, such as steroidogenesis, proliferation, apoptosis, and oxidative stress. In females, it controls steroidogenesis of ovarian granulosa and theca cells, oocyte maturation, and embryo development. Adiponectin receptors were also found in placental and endometrial cells, suggesting that this adipokine might play a crucial role in embryo implantation, trophoblast invasion and foetal growth. The aim of this review is to characterise adiponectin expression and its mechanism of action in male and female reproductive tract. Further, since features of metabolic syndrome are associated with some reproductive diseases, such as polycystic ovary syndrome, gestational diabetes mellitus, preeclampsia, endometriosis, foetal growth restriction and ovarian and endometrial cancers, evidence regarding the emerging role of adiponectin in these disorders is also discussed.

Combined inhibition of FGFR and mTOR pathways is effective in suppressing ovarian cancer

The PI3K/AKT/mTOR signaling pathway is considered as a promising therapeutic target in the treatment of ovarian cancer (OC); however, inhibition of this pathway only exhibited moderate clinical efficacy when tested clinically. Combination of mTOR inhibitors with other anticancer compounds could improve the anticancer efficiency. Therefore, the concurrent inhibition of Fibroblast Growth Factor Receptor (FGFR) signaling pathway was evaluated in the present study. OC cell lines were treated with FGFR inhibitor BGJ398, mTOR inhibitor Rapamycin, or combined inhibition of both BGJ398 and Rapamycin. The results revealed that the growth and motility, expression of angiogenic markers and phosphorylation of associated proteins were affected in treated OC cells. Additionally, the anticancer effects of aforementioned inhibitors were evaluated using a murine tumor xenograft model. Combined treatment with BGJ398 and Rapamycin exhibited stronger inhibitory effects on the growth and motility of OC cells compared with BGJ398 or Rapamycin alone group. Furthermore, combined inhibition of FGFR and mTOR pathways by BGJ398 and Rapamycin induced remarkable cell cycle arrest and apoptosis in OC cells. Reduced tumor size in the xenograft was also observed following combined treatment but not in BGJ398 or Rapamycin alone group. The results in the present study revealed that combined inhibition of FGFR and mTOR pathways could be a promising therapeutic strategy in the treatment of patients with OC.

Adenosine triphosphate-based chemotherapy response assay predicts long-term survival of primary epithelial ovarian cancer

OBJECTIVE

The aim of this study is to analyze the long-term relapse-free survival and overall survival outcomes of primary ovarian cancer patients using adenosine triphosphate-based chemotherapy response analysis.

METHODS

In total, 162 primary epithelial ovarian cancer patients who underwent chemotherapy response assay for carboplatin, cisplatin, and paclitaxel by adenosine triphosphate-based chemotherapy response analysis prior to chemotherapy between December 2006 and November 2016 were retrospectively reviewed. Chemosensitivity with single or combined three agents and clinical characteristics of patients were studied to understand their correlation with long-term relapse-free survival and overall survival.

RESULTS

Median follow-up time was 61.4 (range 1 - 130) months. Univariate analysis showed the paclitaxel-sensitive group (HR = 0.625, 95%CI = 0.393 to 0.994), combined carboplatin and paclitaxel-sensitive group (HR = 0.574, 95%CI = 0.352 to 0.937), and combined carboplatin, cisplatin, and paclitaxel-sensitive group (HR = 0.489, 95%CI = 0.295 to 0.810) were highly associated with better relapse-free survival than their corresponding non-sensitive groups. The carboplatin-sensitive group (HR = 0.533, 95%CI = 0.303 to 0.939), cisplatin-sensitive group (HR = 0.433. 95%CI = 0.251 to 0.748), and combined carboplatin- and cisplatin-sensitive group (HR = 0.286, 95%CI = 0.142 to 0.576) were highly associated with better overall survival than their corresponding non-sensitive groups. Combined carboplatin, cisplatin, and paclitaxel chemosensitivity, together with International Federation of Gynecology and Obstetrics (FIGO) stage were independent predictors for relapse-free survival. Single or combined chemosensitivity of cisplatin and/or carboplatin, together with residual tumor size and FIGO stage, were significant independent predictors for overall survival on a multivariate hazard model.

CONCLUSION

Paclitaxel sensitivity is a prognostic factor of long-term relapse-free survival in patients with epithelial ovarian cancer, but platinum sensitivity is a more important prognostic factor for long-term overall survival.

Long noncoding RNA SNHG15 serves as an oncogene and predicts poor prognosis in epithelial ovarian cancer

Objective

This study aims to investigate the functional role of long noncoding RNA SNHG15 in epithelial ovarian cancer (EOC).

Materials and methods

The expression of SNHG15 was measured in EOC cells and tissues using qRT-PCR. The correlation of SNHG15 expression and the clinicopathological characters was statistically analyzed. The prognosis of patients with different clinical features in the high/low SNHG15 expression groups were calculated. Moreover, univariate and multivariate Cox regression analyses were performed to identify the risk factors for poor overall survival (OS) and progression-free survival (PFS). The effect of SNHG15 on the migration and invasion was evaluated using Transwell and Matrigel, respectively. The proliferation ability of EOC cells was tested using colony formation and MTT assay. The influence of SNHG15 on the cisplatin resistance was detected by measuring cell inhibition rate and cell viability.

Results

SNHG15 was upegulated in EOC cells and tissues. High SNHG15 expression was correlated with EOC progression and predicted poor OS and PFS in different subgroups of EOC patients. Moreover, multivariate Cox regression analysis defined high SNHG15 expression as an independent risk factor for poor OS and PFS. Furthermore, functional assays showed that the overexpression of SNHG15 promoted migration and invasion, while the loss of SNHG15 suppressed migration and invasion. Furthermore, the proliferation of EOC cells was improved after the ectopic expression of SNHG15, which was suppressed with SNHG15 deficiency. In addition, cisplatin-resistant EOC cells were established for detecting the effect of SNHG15 on EOC chemoresistance. The results showed that cisplatin-resistant EOC cells exhibited much higher levels of SNHG15 expression than controls, and SNHG15 contributed to the chemoresistance of EOC cells.

Conclusion

This study confirms that SNHG15 contributes to the migration, invasion, proliferation, and chemoresistance of EOC. SNHG15 may serve as a potential therapeutic target and prognostic biomarker of EOC patients.

Carbon monoxide sensitizes cisplatin-resistant ovarian cancer cell lines toward cisplatin via attenuation of levels of glutathione and nuclear metallothionein

Cisplatin resistance remains a major impediment to effective treatment of ovarian cancer. Despite initial platinum responsiveness, thiol-containing peptides and proteins, glutathione (GSH) and metallothionein (MT), bind and inactivate cisplatin in cancer cells. Indeed, high levels of GSH and MT in ovarian cancers impart cisplatin resistance and are predictive of poor prognosis. Cystathionine β-synthase (CBS), an enzyme involved in sulfur metabolism, is overexpressed in ovarian cancer tissues and is itself associated with cisplatin resistance. Treatment with exogenous carbon monoxide (CO), a known inhibitor of CBS, may mitigate cisplatin resistance in ovarian cancer cells by attenuation of GSH and MT levels. Using a photo-activated CO-releasing molecule (photoCORM), [Mn(CO)₃(phen)(PTA)]CF₃SO₃ (phen = 1,10-phenanthroline, PTA = 1,3,5-triza-7-phosphaadamantane) we assessed the ability of CO to sensitize established cisplatin-resistant ovarian cancer cell lines to cisplatin. Cisplatin-resistant cells, treated with both cisplatin and CO, exhibited significantly lower cell viability and increased poly (ADP-ribose) polymerase (PARP) cleavage versus those treated with cisplatin alone. These cisplatin-resistant cell lines overexpressed CBS and had increased steady state levels of GSH and expression of nuclear MT. Both CO treatment and lentiviral-mediated silencing of CBS attenuated GSH and nuclear MT expression in cisplatin resistant cells. We have demonstrated that CO, delivered from a photoCORM, sensitizes established cisplatin-resistant cell lines to cisplatin. Furthermore, we have presented strong evidence that the effects of CO in circumventing chemotherapeutic drug resistance is at least in part mediated by the inactivation of endogenous CBS.

Sphingolipid metabolism and drug resistance in ovarian cancer

Despite progress in understanding molecular aberrations that contribute to the development and progression of ovarian cancer, virtually all patients succumb to drug resistant disease at relapse. Emerging data implicate bioactive sphingolipids and regulation of sphingolipid metabolism as components of response to chemotherapy or development of resistance. Increases in cytosolic ceramide induce apoptosis in response to therapy with multiple classes of chemotherapeutic agents. Aberrations in sphingolipid metabolism that accelerate the catabolism of ceramide or that prevent the production and accumulation of ceramide contribute to resistance to standard of care platinum- and taxane-based agents. The aim of this review is to highlight current literature and research investigating the influence of the sphingolipids and enzymes that comprise the sphingosine-1-phosphate pathway on the progression of ovarian cancer. The focus of the review is on the utility of sphingolipid-centric therapeutics as a mechanism to circumvent drug resistance in this tumor type.

Oldhamianoside inhibits the growth of ovarian cancer both in vitro and in vivo via adjusting inflammation and angiogenesis signals

Objective

The aim of this study was to determine the effects and possible mechanisms of oldhamianoside on the growth of human ovarian cancer both in vitro and in vivo.

Materials and methods

CCK-8 assay was applied to estimate the effect of oldhamianoside on cell proliferation inhibition in vitro. Nude mice bearing human ovarian SKOV3 xenograft tumors were treated with oldhamianoside to investigate the effects of compound administration on tumor growth in vivo. To further investigate the mechanisms of inhibition effects of oldhamianoside on ovarian cancer growth in vivo, the levels of TNF-α, IL-6, and MCP-1 in plasma from the mice were measured by ELISA. Western blot was used to detect the expression of angiogenesis- and/or apoptosis-related proteins.

Results

We found that oldhamianoside treatment inhibited SKOV3 proliferation and growth both in vitro and in vivo. Meanwhile, the levels of TNF-α, IL-6, and MCP-1 in plasma were markedly suppressed in oldhamianoside-treated mice. Additionally, oldhamianoside treatment inhibited the expression of VEGF and VEGFR2 and decreased the expression of caspase-3 and Bax/Bcl-2 ratio.

Conclusion

Our data indicate that oldhamianoside has an obvious inhibition effect on SKOV3 proliferation, and the mechanisms might be related to inhibition of cell growth, apoptosis induction, and adjusting the inflammatory response and angiogenesis signal.

Itaconic acid mediates crosstalk between macrophage metabolism and peritoneal tumors

Control of cellular metabolism is critical for efficient cell function, although little is known about the interplay between cell subset–specific metabolites in situ, especially in the tumor setting. Here, we determined how a macrophage-specific (Mϕ-specific) metabolite, itaconic acid, can regulate tumor progression in the peritoneum. We show that peritoneal tumors (B16 melanoma or ID8 ovarian carcinoma) elicited a fatty acid oxidation–mediated increase in oxidative phosphorylation (OXPHOS) and glycolysis in peritoneal tissue–resident macrophages (pResMϕ). Unbiased metabolomics identified itaconic acid, the product of immune-responsive gene 1–mediated (Irg1-mediated) catabolism of mitochondrial cis-aconitate, among the most highly upregulated metabolites in pResMϕ of tumor-bearing mice. Administration of lentivirally encoded Irg1 shRNA significantly reduced peritoneal tumors. This resulted in reductions in OXPHOS and OXPHOS-driven production of ROS in pResMϕ and ROS-mediated MAPK activation in tumor cells. Our findings demonstrate that tumors profoundly alter pResMϕ metabolism, leading to the production of itaconic acid, which potentiates tumor growth. Monocytes isolated from ovarian carcinoma patients’ ascites fluid expressed significantly elevated levels of IRG1. Therefore, IRG1 in pResMϕ represents a potential therapeutic target for peritoneal tumors.

Charged-Iron-Particles Found in Galactic Cosmic Rays are Potent Inducers of Epithelial Ovarian Tumors

Astronauts traveling in deep space are exposed to high-charge and energy (HZE) particles from galactic cosmic rays. We have previously determined that irradiation of adult female mice with iron HZE particles induces DNA double-strand breaks, oxidative damage and apoptosis in ovarian follicles, causing premature ovarian failure. These effects occur at lower doses than with conventional photon irradiation. Ovarian failure with resultant loss of negative feedback and elevated levels of gonadotropin hormones is thought to play a role in the pathophysiology of ovarian cancer. Therefore, we hypothesized that charged-iron-particle irradiation induces ovarian tumorigenesis in mice. In this study, three-month-old female mice were exposed to 0 cGy (sham) or 50 cGy iron ions and aged to 18 months. The 50 cGy irradiated mice had increased weight gain with age and lack of estrous cycling, consistent with ovarian failure. A total of 47% and 7% of mice irradiated with 50 cGy had unilateral and bilateral ovarian tumors, respectively, whereas 14% of mice in the 0 cGy group had unilateral tumors. The tumors contained multiple tubular structures, which were lined with cells positive for the epithelial marker cytokeratin, and had few proliferating cells. In some tumors, packets of cells between the tubular structures were immunopositive for the granulosa cell marker FOXL2. Based on these findings, tumors were diagnosed as tubular adenomas or mixed tubular adenoma/granulosa cell tumors. In conclusion, charged-iron-particle-radiation induces ovarian tumors in mice, raising concerns about ovarian tumors as late sequelae of deep space travel in female astronauts.

Intraperitoneal nanotherapy for metastatic ovarian cancer based on siRNA-mediated suppression of DJ-1 protein combined with a low dose of cisplatin

Herein, we report an efficient combinatorial therapy for metastatic ovarian cancer based on siRNA-mediated suppression of DJ-1 protein combined with a low dose of cisplatin. DJ-1 protein modulates, either directly or indirectly, different oncogenic pathways that support and promote survival, growth, and invasion of ovarian cancer cells. To evaluate the potential of this novel therapy, we have engineered a cancer-targeted nanoplatform and validated that DJ-1 siRNA delivered by this nanoplatform after intraperitoneal injection efficiently downregulates the DJ-1 protein in metastatic ovarian cancer tumors and ascites. In vivo experiments revealed that DJ-1 siRNA monotherapy outperformed cisplatin alone by inhibiting tumor growth and increasing survival of mice with metastatic ovarian cancer. Finally, three cycles of siRNA-mediated DJ-1 therapy in combination with a low dose of cisplatin completely eradicated ovarian cancer tumors from the mice, and there was no cancer recurrence detected for the duration of the study, which lasted 35 weeks.

Adiponectin Reverses the Proliferative Effects of Estradiol and IGF-1 in Human Epithelial Ovarian Cancer Cells by Downregulating the Expression of Their Receptors

The expression of adiponectin receptors AdipoR1 and AdipoR2 has been reported in the human ovary and ovarian cancer tissues. Moreover, adiponectin has been reported to act as an anti-tumor factor by inhibiting cancer cell proliferation. Thus, we investigate whether adiponectin and its receptors influence ovarian cancer development. In the present study, we found that adiponectin was not expressed in the granulosa cell line (COV434), and epithelial ovarian cancer cell lines (OVCAR-3, SKOV-3, and Caov-3). Additionally, we found that AdipoR1 and AdipoR2 expression is lower in epithelial ovarian cancer cells than in granulosa tumor cells. Endogenous 17β-estradiol as well as exogenous estrogens, such as bisphenol A and its chlorinated and brominated analogs do not affect adiponectin receptor expression. We found that adiponectin inhibited the growth of OVCAR-3 and SKOV-3 cells, and that this effect was independent of apoptosis. Moreover, adiponectin reverses the stimulatory effects of 17β-estradiol and insulin-like growth factor 1 on cell proliferation by downregulating the expression of their receptors, whereas progesterone increased the sensitivity of cancer cells to adiponectin by upregulating AdipoR1 and AdipoR2 expression. These results suggest interactions between adiponectin and various ovarian steroid hormone and growth factor pathways in ovarian cancer cells.

The anti-tumor efficacy of 3C23K, a glyco-engineered humanized anti-MISRII antibody, in an ovarian cancer model is mainly mediated by engagement of immune effector cells

Ovarian cancer is the leading cause of death in women with gynecological cancers and despite recent advances, new and more efficient therapies are crucially needed. Müllerian Inhibiting Substance type II Receptor (MISRII, also named AMHRII) is expressed in most ovarian cancer subtypes and is a novel potential target for ovarian cancer immunotherapy. We previously developed and tested 12G4, the first murine monoclonal antibody (MAb) against human MISRII. Here, we report the humanization, affinity maturation and glyco-engineering steps of 12G4 to generate the Fc-optimized 3C23K MAb, and the evaluation of its in vivo anti-tumor activity. The epitopes of 3C23K and 12G4 were strictly identical and 3C23K affinity for MISRII was enhanced by a factor of about 14 (K_D = 5.5 × 10⁻¹¹ M vs 7.9 × 10⁻¹⁰ M), while the use of the EMABling^® platform allowed the production of a low-fucosylated 3C23K antibody with a 30-fold K_D improvement of its affinity to FcγRIIIa. In COV434-MISRII tumor-bearing mice, 3C23K reduced tumor growth more efficiently than 12G4 and its combination with carboplatin was more efficient than each monotherapy with a mean tumor size of 500, 1100 and 100 mm³ at the end of treatment with 3C23K (10 mg/kg, Q3-4D12), carboplatin (60 mg/kg, Q7D4) and 3C23K+carboplatin, respectively. Conversely, 3C23K-FcKO, a 3C23K form without affinity for the FcγRIIIa receptor, did not display any anti-tumor effect in vivo. These results strongly suggested that 3C23K mechanisms of action are mainly Fc-related. In vitro, antibody-dependent cytotoxicity (ADCC) and antibody-dependent cell phagocytosis (ADCP) were induced by 3C23K, as demonstrated with human effector cells. Using human NK cells, 50% of the maximal lysis was obtained with a 46-fold lower concentration of low-fucosylated 3C23K (2.9 ng/ml) than of 3C23K expressed in CHO cells (133.35 ng/ml). As 3C23K induced strong ADCC with human PBMC but almost none with murine PBMC, antibody-dependent cell phagocytosis (ADCP) was then investigated. 3C23K-dependent (100 ng/ml) ADCP was more active with murine than human macrophages (only 10% of living target cells vs. about 25%). These in vitro results suggest that the reduced ADCC with murine effectors could be partially balanced by ADCP activity in in vivo experiments. Taken together, these preclinical data indicate that 3C23K is a new promising therapeutic candidate for ovarian cancer immunotherapy and justify its recent introduction in a phase I clinical trial.

Ovarian tumour growth is characterized by mevalonate pathway gene signature in an orthotopic, syngeneic model of epithelial ovarian cancer

Epithelial ovarian cancer (EOC) is the most lethal gynecological cancer and often is not detected until late stages when cancer cells transcoelomically metastasize to the abdomen and typically become resistant to therapy resulting in very low survival rates. We utilize an orthotopic, syngeneic mouse model to study late stage disease and have discovered that the tumor cells within the abdominal ascites are irreversibly re-programmed, with an increased tumorigenicity and resistance to apoptosis. The goal of this study was to characterize the reprogramming that occurred in the aggressive ascites-derived cells (28-2 cells) compared to the original cell line used for tumor induction (ID8 cells). Microarray experiments showed that the majority of genes upregulated in the 28-2 cells belonged to the mevalonate pathway, which is involved in cholesterol biosynthesis, protein prenylation, and activation of small GTPases. Upregulation of mevalonate appeared to be associated with the acquisition of a p53 mutation in the ascites-derived cells. Treatment with simvastatin to inhibit HMG CoA reductase, the rate limiting enzyme of this pathway, induced apoptosis in the 28-2 cell line. Rescue experiments revealed that mevalonate, but not cholesterol, could inhibit the simvastatin-mediated effects. In vivo, daily intraperitoneal simvastatin treatment significantly regressed advanced stage disease and induced death of metastatic tumor cells. These data suggest that ovarian cancer cells become reprogrammed, with genetic mutations, and upregulation of the mevalonate pathway, which facilitates the development of advanced stage disease. The use of statins to inhibit HMGCR may provide novel therapeutic opportunities for the treatment of advanced stage EOC.

PIM Kinases and Their Relevance to the PI3K/AKT/mTOR Pathway in the Regulation of Ovarian Cancer

Ovarian cancer is a medical term that includes a number of tumors with different molecular biology, phenotypes, tumor progression, etiology, and even different diagnosis. Some specific treatments are required to address this heterogeneity of ovarian cancer, thus molecular characterization may provide an important tool for this purpose. On a molecular level, proviral-integration site for Moloney-murine leukemia virus (PIM) kinases are over expressed in ovarian cancer and play a vital role in the regulation of different proteins responsible for this tumorigenesis. Likewise, the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway is also a central regulator of the ovarian cancer. Interestingly, recent research has linked the PIM kinases to the PI3K/AKT/mTOR pathway in several types of cancers, but their connection in ovarian cancer has not been studied yet. Once the exact relationship of PIM kinases with the PI3K/AKT/mTOR pathway is acquired in ovarian cancer, it will hopefully provide effective treatments on a molecular level. This review mainly focuses on the role of PIM kinases in ovarian cancer and their interactions with proteins involved in its progression. In addition, this review suggests a connection between the PIM kinases and the PI3K/AKT/mTOR pathway and their parallel mechanism in the regulation of ovarian cancer.

Leptin induces matrix metalloproteinase 7 expression to promote ovarian cancer cell invasion by activating ERK and JNK pathways

Leptin, an adipokine secreted by adipose tissue, induces cell invasion and metastasis. MMP7 is a member of the matrix metalloproteinase family that plays an important role in cell invasion. Here we evaluate the possible role and underlying mechanism of MMP7 in the leptin-mediated cell invasion in ovarian cancer cell lines. All experiments were carried out in cultured SKOV3, OVCAR3, and CaoV-3 ovarian cell lines. MMP7 expression was determined using the Western blot following treatment to various concentrations of leptin for defined time intervals. The activation of ERK, JNK, and P38 MAP kinases were determined using Western blotting. Wound healing and BD matrigel invasion assays were used to measure cell migration and invasion. The siRNA approach and pharmacological inhibitors of ERK and JNK pathway were used to confirm the receptor-dependent effect of leptin and a role for ERK and JNK pathway. Zymography assay was employed to determine MMP2 and MMP9 activation. Results show that leptin induces ERK1/2 and JNK1/2 activation and subsequently promotes MMP7 expression in SKOV3 (4.8 ± 0.14 fold of control, P < 0.01) and OVCAR3 (3.1 ± 0.19 fold of control, P < 0.01) ovarian cancer cell lines. These effects was reversed by knockdown of OB-Rb and/or pre-incubation with PD98059 (ERK1/2 inhibitor), SP600125 (JNK1/2 inhibitor). Gelatin zymography showed that MMP7 gene silencing attenuated leptin-induced MMP9 activation in SKOV3 cell line. Taken together, our results suggest new evidences for a modulatory effect of leptin in regulation of ovarian cancer cell invasion by stimulating MMP7 expression via ERK and JNK pathways.

Vitamin D receptor rs2228570 polymorphism and susceptibility to ovarian cancer: An updated meta-analysis

AIM

The FokI polymorphism (C>T, rs2228570) of the vitamin D receptor gene is a coding nonsynonymous single nucleotide polymorphism in the translational initiation codon reported to have functional significance. Although the role of rs2228570 in the risk of ovarian cancer has been widely researched, the association is still unclear. We performed an updated meta-analysis to clarify this issue.

METHODS

Eligible studies were retrieved from electronic databases for the period 2007-2016. The association was measured by unadjusted odds ratio combined with 95% confidence intervals (CIs). Random-effect or fixed-effect models were used according to the heterogeneity of the studies. We further appreciated the strength of evidence according to Venice guidance.

RESULTS

Fourteen studies (4448 cases and 7242 controls) were included in the meta-analysis. Studies were predominantly conducted in Caucasian populations (4152 cases and 6693 controls). A dominant genetic model was determined to be the most appropriate genetic model. Overall meta-analysis showed a fixed-effect odds ratio of 1.14 (95% CI 1.05-1.23) under a dominant model. The fixed-effect odds ratios were 1.12 (95% CI 1.03-1.21) and 1.49 (95% CI 1.06-2.09) in Caucasian and Asian populations, respectively. The strength of the evidence was moderate.

CONCLUSION

The rs2228570 polymorphism increased the risk of ovarian cancer in Caucasian populations in a dominant genetic model. The role of this polymorphism in the risk of ovarian cancer in Asian populations should be further studied.

Rethinking ovarian cancer genomics: where genome-wide association studies stand?

Genome-wide association studies (GWAS) allow the finding of genetic variants associated with several traits. Regarding ovarian cancer (OC), 15 GWAS have been conducted since 2009, with the discovery of 49 SNPs associated with disease susceptibility and 46 with impact in the clinical outcome of patients (p < 5.00 × 10-2). Among them, 14 variants reached the genome-wide significance (p < 5.00 × 10−8). Despite the results obtained, they should be validated in independent sets. So far, five validation studies have been conducted which could confirm the association of 12 OC susceptibility SNPs. Consequently, post-GWAS studies are crucial unravel the biological plausibility of GWAS’ findings and the allelic spectrum of OC.

Genetic variants as ovarian cancer first-line treatment hallmarks: A systematic review and meta-analysis

BACKGROUND

The potential predictive value of genetic polymorphisms in ovarian cancer first-line treatment is inconsistently reported. We aimed to review ovarian cancer pharmacogenetic studies to update and summarize the available data and to provide directions for further research.

METHODS

A systematic review followed by a meta-analysis was conducted on cohort studies assessing the involvement of genetic polymorphisms in ovarian cancer first-line treatment response retrieved through a MEDLINE database search by November 2016. Studies were pooled and summary estimates and 95% confidence intervals (CI) were calculated using random or fixed-effects models as appropriate.

RESULTS

One hundred and forty-two studies gathering 106871 patients were included. Combined data suggested that GSTM1-null genotype patients have a lower risk of death compared to GSTM1-wt carriers, specifically in advanced stages (hazard ratio (HR), 0.68; 95% CI, 0.48-0.97) and when submitted to platinum-based chemotherapy (aHR, 0.61; 95% CI, 0.39-0.94). ERCC1 rs11615 and rs3212886 might have also a significant impact in treatment outcome (aHR, 0.67; 95% CI, 0.51-0.89; aHR, 1.28; 95% CI, 1.01-1.63, respectively). Moreover, ERCC2 rs13181 and rs1799793 showed a distinct ethnic behavior (Asians: aHR, 1.41; 95% CI, 0.80-2.49; aHR, 1.07; 95% CI, 0.62-1.86; Caucasians: aHR, 0.10; 95% CI, 0.01-0.96; aHR, 0.18; 95% CI, 0.05-0.68, respectively).

CONCLUSION(S)

The definition of integrative predictive models should encompass genetic information, especially regarding GSTM1 homozygous deletion. Justifying additional pharmacogenetic investigation are variants in ERCC1 and ERCC2, which highlight the DNA Repair ability to ovarian cancer prognosis. Further knowledge could aid to understand platinum-treatment failure and to tailor chemotherapy strategies.

Formyl peptide receptor 2 expression predicts poor prognosis and promotes invasion and metastasis in epithelial ovarian cancer

Formyl peptide receptor 2 (FPR2) has been identified as a member of the G protein-coupled chemoattractant receptor (GPCR) family and has been implicated as playing a role in both inflammation and cancer development. Epithelial ovarian cancer (EOC) has been suggested to be correlated with both infectious and non-infectious inflammation. To date, the role of FPR2 in EOC remains poorly understood and controversial. In the present study, we aimed to investigate the potential of FPR2 in regulating EOC. We performed immunohistochemistry and RT-qPCR to analyzed expression of FPR2 in EOC tissues and the correlation between FPR2 and EOC clinicopathological characteristics as well as prognosis were also analyzed. To test the role of FPR2 in EOC cell migration, we established FPR2-knockdown SKOV3 cells and performed wound-healing, Transwell and angiogenesis assays to detect the metastatic potential of these EOC cells. Our studies found that FPR2 was overexpressed in EOC tissues and was positively correlated with EOC clinicopathological characteristics including the International Federation of Gynecology and Obstetrics (FIGO) stage, histological grade and ovarian cancer type. Survival analyses suggested that FPR2 overexpression indicated the poorer prognosis of EOC patients and FPR2 may act as an independent risk factor for EOC prognosis. FPR2 knockdown decreased the migration potential of the ovarian cancer cells. Moreover, serum amyloid A (SAA) may stimulate the migration of SKOV3 cells through FPR2. The present study suggested that FPR2 promoted the invasion and metastasis of EOC and it could be a prognostic marker for EOC.