Epithelial ovarian cancer

Inhibition of CDK4/6 as Therapeutic Approach for Ovarian Cancer Patients: Current Evidences and Future Perspectives

Simple Summary

Altered regulation of the cell cycle is a hallmark of cancer. The recent clinical success of the inhibitors of CDK4 and CDK6 has convincingly demonstrated that targeting cell cycle components may represent an effective anti-cancer strategy, at least in some cancer types. However, possible applications of CDK4/6 inhibitors in patients with ovarian cancer is still under evaluation. Here, we describe the possible biological role of CDK4 and CDK6 complexes in ovarian cancer and provide the rationale for the use of CDK4/6 inhibitors in this pathology, alone or in combination with other drugs. This review, coupling basic, preclinical and clinical research studies, could be of great translational value for investigators attempting to design new clinical trials for the better management of ovarian cancer patients.

Abstract

Alterations in components of the cell-cycle machinery are present in essentially all tumor types. In particular, molecular alterations resulting in dysregulation of the G1 to S phase transition have been observed in almost all human tumors, including ovarian cancer. These alterations have been identified as potential therapeutic targets in several cancer types, thereby stimulating the development of small molecule inhibitors of the cyclin dependent kinases. Among these, CDK4 and CDK6 inhibitors confirmed in clinical trials that CDKs might indeed represent valid therapeutic targets in, at least some, types of cancer. CDK4 and CDK6 inhibitors are now used in clinic for the treatment of patients with estrogen receptor positive metastatic breast cancer and their clinical use is being tested in many other cancer types, alone or in combination with other agents. Here, we review the role of CDK4 and CDK6 complexes in ovarian cancer and propose the possible use of their inhibitors in the treatment of ovarian cancer patients with different types and stages of disease.

PARP inhibitors promote stromal fibroblast activation by enhancing CCL5 autocrine signaling in ovarian cancer

Cancer-associated fibroblasts (CAFs) play significant roles in drug resistance through different ways. Antitumor therapies, including molecular targeted interventions, not only effect tumor cells but also modulate the phenotype and characteristics of CAFs, which can in turn blunt the therapeutic response. Little is known about how stromal fibroblasts respond to poly (ADP-ribose) polymerase inhibitors (PARPis) in ovarian cancer (OC) and subsequent effects on tumor cells. This is a study to evaluate how CAFs react to PARPis and their potential influence on PARPi resistance in OC. We discovered that OC stromal fibroblasts exhibited intrinsic resistance to PARPis and were further activated after the administration of PARPis. PARPi-challenged fibroblasts displayed a specific secretory profile characterized by increased secretion of CCL5, MIP-3α, MCP3, CCL11, and ENA-78. Mechanistically, increased secretion of CCL5 through activation of the NF-κB signaling pathway was required for PARPi-induced stromal fibroblast activation in an autocrine manner. Moreover, neutralizing CCL5 partly reversed PARPi-induced fibroblast activation and boosted the tumor inhibitory effect of PARPis in both BRCA1/2-mutant and BRCA1/2-wild type xenograft models. Our study revealed that PARPis could maintain and improve stromal fibroblast activation involving CCL5 autocrine upregulation. Targeting CCL5 might offer a new treatment modality in overcoming the reality of PARPi resistance in OC.

Diffusion-weighted MRI and PET/CT reproducibility in epithelial ovarian cancers during neoadjuvant chemotherapy

PURPOSE

To investigate the reproducibility of diffusion-weighted (DW) MRI and ¹⁸F-Fluorodeoxyglucose (¹⁸F-FDG)-Positron emission tomography/CT (PET/CT) in monitoring response to neoadjuvant chemotherapy in epithelial ovarian cancer.

MATERIALS AND METHODS

Ten women (median age, 67 years; range: 41.8-77.3 years) with stage IIIC-IV epithelial ovarian cancers were included in this prospective trial (NCT02792959) between 2014 and 2016. All underwent initial laparoscopic staging, four cycles of carboplatine-paclitaxel-based chemotherapy and interval debulking surgery. PET/CT and DW-MRI were performed at baseline (C0), after one cycle (C1) and before surgery (C4). Two nuclear physicians and two radiologists assessed five anatomic sites for the presence of ≥1 lesion. Target lesions in each site were defined and their apparent diffusion coefficient (ADC), maximal standardized uptake value (SUV-max), SUV-mean, SUL-peak, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were monitored (i.e., 10 patients ×5 sites ×3 time-points). Their relative early and late changes were calculated. Intra/inter-observer reproducibilities of qualitative and quantitative analysis were estimated with Kappa and intra-class correlation coefficients (ICCs).

RESULTS

For both modalities, inter- and intra-observer agreement percentages were excellent for initial staging but declined later for DW-MRI, leading to lower Kappa values for inter- and intra-observer variability (0.949 and 1 at C0, vs. 0.633 and 0.643 at C4, respectively) while Kappa values remained>0.8 for PET/CT. Inter- and intra-observer ICCs were>0.75 for SUV-max, SUL-peak, SUV-mean and their change regardless the time-point. ADC showed lower ICCs (range: 0.013-0.811). ANOVA found significant influences of the evaluation time, the measurement used (ADC, SUV-max, SUV-mean, SUV-max, SUL-peak, MTV or TLG) and their interaction on ICC values (P=0.0023, P<0.0001 and P =0.0028, respectively).

CONCLUSION

While both modalities demonstrated high reproducibility at baseline, only SUV-max, SUL-peak, SUV-mean and their changes maintained high reproducibility during chemotherapy.

Preparation and Performance of Chemotherapy Drug-Loaded Graphene Oxide-Based Nanosheets That Target Ovarian Cancer Cells via Folate Receptor Mediation

Graphene oxide (GO) is one of the most popular nanomaterials that widely used to achieve effective cancer treatment. In this study, a novel, folic acid-decorated graphene oxide (FA-GO)-mediated drug delivery system was synthesized by loading the chemotherapy drug cisplatin (CDDP) or paclitaxel (PTX) to the large surface area of GO for ovarian cancer target therapy. In vitro study showed that the therapeutic effects of FA-GO-CDDP or FA-GO-PTX were increased with folate-binding protein (FBP) expression levels. The GO-CDDP or GO-PTX modified with FA enhanced cancer cell death by promoting DNA damage, ROS production, and apoptotic pathway activation. In vivo anticancer study demonstrated that FA-GO-CDDP nanosheets showed excellent therapeutic performance and attenuated the body weight loss evoked by CDDP treatment. Our results indicate that the chemotherapy agent-loaded FA-GO nanosheets have high potential therapeutic effects against FBP high expressing ovarian cancer.

Prognostic image-based quantification of CD8CD103 T cell subsets in high-grade serous ovarian cancer patients

CD103-positive tissue resident memory-like CD8+ T cells (CD8CD103 TRM) are associated with improved prognosis across malignancies, including high-grade serous ovarian cancer (HGSOC). However, whether quantification of CD8, CD103 or both is required to improve existing survival prediction and whether all HGSOC patients or only specific subgroups of patients benefit from infiltration, remains unclear. To address this question, we applied image-based quantification of CD8 and CD103 multiplex immunohistochemistry in the intratumoral and stromal compartments of 268 advanced-stage HGSOC patients from two independent clinical institutions. Infiltration of CD8CD103 immune cell subsets was independent of clinicopathological factors. Our results suggest CD8CD103 TRM quantification as a superior method for prognostication compared to single CD8 or CD103 quantification. A survival benefit of CD8CD103 TRM was observed only in patients treated with primary cytoreductive surgery. Moreover, survival benefit in this group was limited to patients with no macroscopic tumor lesions after surgery. This approach provides novel insights into prognostic stratification of HGSOC patients and may contribute to personalized treatment strategies in the future.

CREBBP knockdown suppressed proliferation and promoted chemo-sensitivity via PERK-mediated unfolded protein response in ovarian cancer

CREBBP, in short CBP, has been reported to be involved in tumorigenesis in various cancers, but its role in ovarian cancer remains largely unexplored. In our study, survival analysis of CBP in patients with ovarian cancer was conducted using the Kaplan-Meier Plotter database, then we utilized specific shRNA targeting CREBBP to block the expression of CBP, and detected its effect on cell proliferation and chemo-sensitivity in ovarian cancer cells. The results showed that high expression of CBP was correlated with poor prognosis in ovarian cancer patients. CREBBP knockdown in ovarian cancer cells significantly inhibited tumor proliferation both in vitro and in vivo. Moreover, CREBBP knockdown promoted chemo-sensitivity in ovarian cancer cells. Mechanism research further demonstrated that CREBBP knockdown attenuated unfolded protein response (UPR), which was mediated by PERK/ATF4/STC2 signaling pathway. Our research linked CBP and UPR in ovarian cancer and may provide new strategies for the clinical treatment of ovarian cancer.

Molecular characteristics and tumorigenicity of ascites-derived tumor cells: mitochondrial oxidative phosphorylation as a novel therapy target in ovarian cancer

Ovarian cancer disseminates primarily intraperitoneally. Detached tumor cell aggregates (spheroids) from the primary tumor are regarded as ‘metastatic units’ that exhibit a low sensitivity to classical chemotherapy, probably due to their unique molecular characteristics. We have analyzed the cellular composition of ascites from OvCa patients, using flow cytometry, and studied their behavior in vitro and in vivo. We conclude that ascites‐derived cultured cells from OvCa patients give rise to two subpopulations: adherent cells and non‐adherent cells. Here, we found that the AD population includes mainly CD90⁺ cells with highly proliferative rates in vitro but no tumorigenic potential in vivo, whereas the NAD population contains principally tumor cell spheroids (EpCAM⁺/CD24⁺) with low proliferative potential in vitro. Enriched tumor cell spheroids from the ascites of high‐grade serous OvCA patients, obtained using cell strainers, were highly tumorigenic in vivo and their metastatic spread pattern precisely resembled the tumor dissemination pattern found in the corresponding patients. Comparative transcriptome analyses from ascites‐derived tumor cell spheroids (n = 10) versus tumor samples from different metastatic sites (n = 30) revealed upregulation of genes involved in chemoresistance (TGM1, HSPAs, MT1s), cell adhesion and cell‐barrier integrity (PKP3, CLDNs, PPL), and the oxidative phosphorylation process. Mitochondrial markers (mass and membrane potential) showed a reduced mitochondrial function in tumoroids from tumor tissue compared with ascites‐derived tumor spheroids in flow cytometry analysis. Interestingly, response to OXPHOS inhibition by metformin and IACS010759 in tumor spheroids correlated with the extent of mitochondrial membrane potential measured by fluorescence‐activated cell sorting. Our data contribute to a better understanding of the biology of ovarian cancer spheroids and identify the OXPHOS pathway as new potential treatment option in advanced ovarian cancer.

ELFN1-AS1 accelerates cell proliferation, invasion and migration via regulating miR-497-3p/CLDN4 axis in ovarian cancer

Previous studies indicated that long non-coding RNAs (LncRNAs) were involved in the progression of multiple cancers including ovarian cancer (OV). LncRNA ELFN1-AS1 functioned as an oncogene in many cancers, but its potential roles in OV were largely unclear. In the current study, we were aimed at clarifying the biological roles and molecular mechanisms of ELFN1-AS1 in OV. We found that ELFN1-AS1 was significantly upregulated in OV tissues and cell lines. High expression of ELFN1-AS1 was associated with poor prognosis in OV patients. Knockdown of ELFN1-AS1 inhibited the proliferation, migration and invasion of SKOV3 cell lines and repressed tumor growth in xenografted ovarian models. Mechanistically, ELFN1-AS1 promoted the proliferation, migration and invasion of SKOV3 cells by sponging miR-497-3p. Additionally, CLDN4 was verified to be the target of miR-497-3p. Rescue experiments revealed that miR-497-3p inhibition could partly reverse the inhibitory effect of ELFN1-AS1 silencing on proliferation, migration and invasion of SKOV3 cell lines. Taken together, our findings indicated that ELFN1-AS1 acted as an oncogene in ovarian cancer through regulating the expression of CLDN4 by directly interacting with miR-497-3p. The results suggested that ELFN1-AS1 might act as a promising therapeutic target for OV.

Inhibition of the mTOR pathway and reprogramming of protein synthesis by MDM4 reduce ovarian cancer metastatic properties

Epithelial ovarian cancer (EOC) is a highly heterogeneous disease with a high death rate mainly due to the metastatic spread. The expression of MDM4, a well-known p53-inhibitor, is positively associated with chemotherapy response and overall survival (OS) in EOC. However, the basis of this association remains elusive. We show that in vivo MDM4 reduces intraperitoneal dissemination of EOC cells, independently of p53 and an immune-competent background. By 2D and 3D assays, MDM4 impairs the early steps of the metastatic process. A 3D-bioprinting system, ad hoc developed by co-culturing EOC spheroids and endothelial cells, showed reduced dissemination and intravasation into vessel-like structures of MDM4-expressing cells. Consistent with these data, high MDM4 levels protect mice from ovarian cancer-related death and, importantly, correlate with increased 15 y OS probability in large data set analysis of 1656 patients. Proteomic analysis of EOC 3D-spheroids revealed decreased protein synthesis and mTOR signaling, upon MDM4 expression. Accordingly, MDM4 does not further inhibit cell migration when its activity towards mTOR is blocked by genetic or pharmacological approaches. Importantly, high levels of MDM4 reduced the efficacy of mTOR inhibitors in constraining cell migration. Overall, these data demonstrate that MDM4 impairs EOC metastatic process by inhibiting mTOR activity and suggest the usefulness of MDM4 assessment for the tailored application of mTOR-targeted therapy.

NLR and BRCA mutational status in patients with high grade serous advanced ovarian cancer

Laboratory-markers of the systemic inflammatory-response, such as neutrophil/lymphocyte-ratio (NLR) have been studied as prognostic factors in several tumors but in OC-patients their role is still controversial and no data about the possible correlation with the BRCA-status has been ever reported. We consecutively enrolled a series of 397 newly diagnosed high-grade serous-advanced OC-patients. All patients were tested for BRCA-mutational-status and blood-parameters have been collected 48 h before staging-surgery. A significant correlation of NLR with disease distribution (p < 0.005) was found and patients with NLR < 4 underwent primary-debulking-surgery more frequently (p-value 0.001), with a lower surgical-complexity-score (p-value 0.002). Regarding survival-data, patients with NLR < 4 had a significant 7-month increase in mPFS (26 vs 19 months, p = 0.009); focusing on the BRCA-status, among both BRCA-mutated and BRCA-wild type patients, those with lower NLR had a significantly prolonged mPFS compared to patients with NLR > 4 (BRCA-mutated: 35 vs 23 months, p = 0.03; BRCA-wt: 19 vs 16 months, p = 0.05). At multivariate-analysis, independent factors of prolonged PFS were BRCA mutational status, having received complete cytoreduction and NLR < 4. Also, the strongest predictors of longer OS were BRCA-mutational status, having received complete cytoreductive surgery, NLR < 4 and age. NLR is confirmed to be a prognostic marker in OC-patients and it seems unrelated with BRCA-mutational status.

Ferroptosis-Related Gene Signature Promotes Ovarian Cancer by Influencing Immune Infiltration and Invasion

Ovarian cancer is a kind of gynecological malignancy with high mortality. Ferroptosis is a new type of iron-dependent cell death characterized by the formation of lipid peroxides and excessive accumulation of reactive oxygen species. Studies have shown that ferroptosis modulates tumor genesis, progression, and invasion, including ovarian cancer. Based on the mRNA expression data from TCGA, we construct a scoring system using consensus clustering analysis, univariate Cox regression analysis, and least absolute selection operator. Then, we systematically evaluate the relationship between score and clinical characteristics of ovarian cancer. The result from the prediction of biofunction pathways shows that score serves as an independent prognostic marker for ovarian cancer and affects tumor progression by modulating tumor metastasis. Moreover, immunocytes such as activated CD4 T cell, activated CD8 T cell, regulatory T cells, macrophage, and stromal cells, including adipocytes, epithelial cells, and fibroblast infiltrate more in the tumor microenvironment in a high-score group, indicating ferroptosis can also affect tumor immune landscape. Critically, four potentially sensitive drugs, including staurosporine, epothilone B, DMOG, and HG6-64-1 based on the scores, are predicted, and DMOG is recognized as a novel targeted drug for ovarian cancer. In general, we construct the scoring system based on ferroptosis-related genes that can predict the prognosis of ovarian cancer patients and propose that ferroptosis may affect ovarian cancer progression by mediating tumor metastasis and immune landscape. Novel drugs to target ovarian cancer are also predicted.

Cyclin-dependent kinase 9 (CDK9) predicts recurrence in Middle Eastern epithelial ovarian cancer

Background

Cyclin-dependent kinase 9 (CDK9) has been shown to play an important role in tumorigenesis of several malignancies. However, the expression of CDK9 in ovarian cancer from Middle Eastern ethnicity remains unknown.

Methods

A tissue microarray of 441 epithelial ovarian cancer (EOC) samples was used to study the expression of CDK9 immunohistochemically and their clinico-pathological associations were determined. Cox proportional hazards regression model was used for univariate and multivariate analysis of recurrence-free survival.

Results

CDK9 over-expression was noted in 56.2 % (248/441) of EOCs and was associated with adverse clinico-pathological parameters such as distant metastasis (p < 0.0001), stage IV tumors (p < 0.0001), tumor recurrence (p = 0.0105) and high Ki-67 index (p < 0.0001). Importantly, CDK9 over-expression was an independent predictor of poor recurrence-free survival (Hazard ratio = 1.51; 95 % confidence interval = 1.15–1.98; p = 0.0030). We also found that CDK9 outperforms Ki-67 as a predictor of tumor recurrence in EOC.

Conclusions

Our results show that CDK9 expression correlates with markers of advanced disease in Middle Eastern EOC and is also a prognostic marker. CDK9 overexpression also identifies a subset of patients with highest likelihood of recurrence across the patient cohort. These patients may benefit from additional alternative therapies targeting CKD9.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-021-00827-8.

ALOX5AP Predicts Poor Prognosis by Enhancing M2 Macrophages Polarization and Immunosuppression in Serous Ovarian Cancer Microenvironment

Background

Serous ovarian cancer (SOC) is a highly lethal gynecological malignancy with poor prognosis. Given the importance of the immune-related tumor microenvironment (TME) in ovarian cancer, investigating tumor-immune interactions and identifying novel prognostic and therapeutic targets in SOC is a promising avenue of research. ALOX5AP (Arachidonate 5-Lipoxygenase Activating Protein) is a key enzyme in converting arachidonic acid to leukotriene: a crucial immune-modulating lipid mediator. However, the role of ALOX5AP in SOC has yet to be studied.

Methods

ALOX5AP expression patterns across ovarian cancer and their normal tissue counterparts were cross-checked using public microarray and RNA-seq analyses and then validated in clinical samples by qRT-PCR. Kaplan-Meier survival analysis was performed in multiple independent SOC patient cohorts. Univariate and multivariate Cox regression analysis were then employed to identify clinical risk parameters associated with survival, and a genomic-clinicopathologic nomogram was built. Gene enrichment, immune infiltration, and immunosuppressor correlation analyses were then evaluated.

Results

ALOX5AP mRNA levels in SOC tissues were significantly upregulated compared to normal tissues. Elevated ALOX5AP was markedly associated with poor overall survival and progression-free survival in multiple SOC patient cohorts as well as with adverse clinicopathological features, including lymphatic invasion, unsatisfactory cytoreductive surgery, rapid relapse after primary treatment, and platinum non-responsiveness. A predictive nomogram, which integrated ALOX5AP expression and two independent prognosis factors (primary therapy outcome and tumor residual), was conducted to predict the 3-year and 5-year survival rate of SOC patients. Mechanistically, functional and pathway enrichment analyses revealed that ALOX5AP was primarily involved in immune response and regulation. Further exploration demonstrated that ALOX5AP was highly expressed in the immunoreactive subtype of ovarian cancer and closely related to immunocyte infiltration, especially M2 macrophage polarization. Additionally, ALOX5AP was enriched in the C4 (lymphocyte depleted) immune subtype of SOC and associated with crucial immune-repressive receptors in the tumor microenvironment at the genomic level.

Conclusions

ALOX5AP expression indicates a worse survival outcome and has the potential to be utilized as a prognostic predictor for SOC patients. Given the availability of well-studied ALOX5AP inhibitors, this study has immediate clinical implications for the exploitation of ALOX5AP as an immunotherapeutic target in SOC.

Association Between Diet Quality and Risk of Ovarian and Endometrial Cancers: A Systematic Review of Epidemiological Studies

Objectives

The relationship between diet quality indices and risk of ovarian and endometrial cancers were unclear. We aimed at conducting a systematic review to evaluate the epidemiological evidence.

Methods

Embase, PubMed, Web of Science and Scopus databases were searched for eligible studies up to December 2020. Epidemiological studies reported the association of the diet quality with risk of ovarian and endometrial cancers were evaluated.

Results

Eleven eligible studies were identified, of which six studies were case-control studies, four were cohort studies, and one was case-cohort study. All studies were considered as high-quality with low risk of bias. Seven studies evaluated the association of diet quality with risk of ovarian cancer. Four studies reported null association for diet quality indices such as Healthy Eating Index (HEI)-2005, HEI-2010, Mediterranean Diet Score (MDS) and Recommended Foods Score (RFS). Two studies reported significantly inverse association for Alternate Healthy Eating Index (AHEI)-2010 and Healthy Diet Score (HDS) indices. One study reported significantly increased risk of ovarian cancer associated with higher level of Dietary Guidelines for Americans Index. Dose-response analysis showed pooled relative risks of 0.98 (95%Cl: 0.95, 1.01) and 0.94 (95%Cl: 0.77, 1.13) for each 10 points increase in the HEI-2005 and AHEI-2010 indices. Seven studies evaluated the association of diet quality with risk of endometrial cancer. Three studies reported significantly inverse association of diet quality as assessed by the MDS and Diet Score Quintiles with risk of endometrial cancer. Four studies reported null association for other diet quality indices including HEI-2005, HEI-2010, RFS and HDS. Dose-response analysis showed a pooled relative risk of 0.87 (95%CI: 0.81, 0.93) for one unit increment of the MDS.

Conclusion

This study suggests little evidence on the association between diet quality and risk of ovarian cancer. Adherence to high quality diet, as assessed by MDS, might be associated with lower the risk of endometrial cancer.

Reduced O-GlcNAcylation of SNAP-23 promotes cisplatin resistance by inducing exosome secretion in ovarian cancer

Exosomes have been associated with chemoresistance in various cancers, but such a role in ovarian cancer is not yet clear. Here, using in vitro cell-based and in vivo mouse model experiments, we show that downregulation of O-GlcNAcylation, a key post-translational protein modification, promotes exosome secretion. This increases exosome-mediated efflux of cisplatin from cancer cells resulting in chemoresistance. Mechanistically, our data indicate that downregulation of O-GlcNAclation transferase (OGT) reduces O-GlcNAclation of SNAP-23. Notably, O-GlcNAcylation of SNAP-23 is vital for regulating exosome release in ovarian cancer cells. Reduced O-GlcNAclation of SNAP-23 subsequently promotes the formation of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex consisting of SNAP-23, VAMP8, and Stx4 proteins. This enhances exosome release causing chemoresistance by increasing the efflux of intracellular cisplatin.

Long non-coding RNA-H19 promotes ovarian cancer cell proliferation and migration via the microRNA-140/Wnt1 axis

To explore the effect and underlying molecular mechanism of long non-coding RNA (lncRNA)-H19 on ovarian cancer (OC) cells, a total of 41 cases of OC and adjacent normal tissues were collected. H19 and microRNA (miR)-140 expressions in OC tissues and cells were detected using quantitative real-time polymerase chain reaction (qRT-RCR). The correlation between H19 expression and prognosis of OC patient was analyzed. siRNA (si)-H19 and si-negative control (NC) were transfected into OC cells. Cell proliferation was checked by cell counting kit-8 assay and colony formation assay, and cell migration and invasion were analyzed via Transwell assay. The targeted binding relationship between H19 and miR-140 was predicted and verified, miR-140 downstream gene was predicted and Wnt1 was screened out. The impact of in-miR-140 on the si-H19-induced decreased OC cell proliferation and migration was evaluated. H19 expression was upregulated in OC tissues and cells, and its overexpression was associated with a poor prognosis of OC. si-H19 remarkably reduced OC cell proliferation and migration. H19 upregulated Wnt1 expression through targeting miR-140 in OC cells. Altogether, miR-140 was notably downregulated in OC, and in-miR-140 partially inhibited the si-H19-induced decrease of OC cell proliferation and migration. H19 competitively bound to miR-140 to upregulate Wnt1, thereby promoting OC cell proliferation and migration.

The attributes of plakins in cancer and disease: perspectives on ovarian cancer progression, chemoresistance and recurrence

The plakin family of cytoskeletal proteins play an important role in cancer progression yet are under-studied in cancer, especially ovarian cancer. These large cytoskeletal proteins have primary roles in the maintenance of cytoskeletal integrity but are also associated with scaffolds of intermediate filaments and hemidesmosomal adhesion complexes mediating signalling pathways that regulate cellular growth, migration, invasion and differentiation as well as stress response. Abnormalities of plakins, and the closely related spectraplakins, result in diseases of the skin, striated muscle and nervous tissue. Their prevalence in epithelial cells suggests that plakins may play a role in epithelial ovarian cancer progression and recurrence. In this review article, we explore the roles of plakins, particularly plectin, periplakin and envoplakin in disease-states and cancers with emphasis on ovarian cancer. We discuss the potential role the plakin family of proteins play in regulating cancer cell growth, survival, migration, invasion and drug resistance. We highlight potential relationships between plakins, epithelial-mesenchymal transition (EMT) and cancer stem cells (CSCs) and discuss how interaction of these processes may affect ovarian cancer progression, chemoresistance and ultimately recurrence. We propose that molecular changes in the expression of plakins leads to the transition of benign ovarian tumours to carcinomas, as well as floating cellular aggregates (commonly known as spheroids) in the ascites microenvironment, which may contribute to the sustenance and progression of the disease. In this review, attempts have been made to understand the crucial changes in plakin expression in relation to progression and recurrence of ovarian cancer.

LncRNA HOTTIP inhibits cell pyroptosis by targeting miR-148a-3p/AKT2 axis in ovarian cancer

Long noncoding RNA HOTTIP is a crucial regulator in multiple types of cancer, including ovarian cancer (OC). However, the biological roles and underlying mechanisms of HOTTIP in OC have rarely been studied. Hence, this study aimed to investigate the functional correlation between HOTTIP and pyroptosis in OC progression. The expression of HOTTIP in OC tissues and cell lines was characterized by quantitative real-time PCR. Cell proliferation was evaluated using Cell Counting Kit-8 and clone formation assays. Western blot was performed to quantify protein levels. A dual-luciferase reporter assay was used to analyze the molecular interaction among HOTTIP, miR-148a-3p, and AKT2. The expression of HOTTIP was significantly upregulated in OC tissue samples and cell lines. The silencing of HOTTIP led to the inhibition of cell proliferation and NLRP1 inflammasome-mediated pyroptosis. In addition, HOTTIP increased AKT2 expression by negatively regulating miR-148a-3p and then inhibited ASK1/JNK signaling. Further rescue experiments revealed that downregulation of miR-148a-3p and overexpression of AKT2 obviously diminished the effects of HOTTIP downregulation in OC cells. Thus, our study elucidated a novel pyroptosis-related mechanism by which HOTTIP participated in OC progression, which might provide a theoretical reference for clinical treatment.

LAMA3 DNA methylation and transcriptome changes associated with chemotherapy resistance in ovarian cancer

Objective

LAMA3 is a widely studied methylated gene in multiple tumors, but the relationship between chemotherapy resistance in ovarian cancer is unclear. In this study, LAMA3 methylation was predicted by bioinformatics, and the ability of LAMA3 methylation to predict the chemotherapy resistance and prognosis of ovarian cancer was confirmed in experiments.

Methods

Multiple databases have performed the bioinformatics analysis of methylation and transcription factor binding site (TFBS) on the promoter region of LAMA3 gene. Pyrosequencing detected the methylation of LAMA3. QRT-PCR and immunohistochemistry detected the expression of LAMA3. Real Time Cell Analyzer (RTCA) detects changes in cell proliferation, migration and invasion ability. Flow cytometry was used to detect apoptosis.

Results

CPG islands of 176 bp, 134 bp, 125 bp and 531 bp were predicted in the promoter region of LAMA3 gene. The 4 prediction results are basically overlapped. 7 transcription factor binding sites were predicted, and the one with the highest score was on the predicted CpG island located in the proximal promoter region. LAMA3 hypermethylation and low expression are both associated with chemotherapy resistance and poor prognosis in ovarian cancer. LAMA3 methylation was negatively correlated with expression. After upregulation of LAMA3, the proliferation ability of chemoresistant ovarian cancer cell decreased, while the ability of apoptosis, invasion and migration increased.

Conclusion

LAMA3 hypermethylation is associated with chemotherapy resistance and poor prognosis. As a typical CpG island gene, LAMA3(cg20937934) and LAMA3(cg13270625) hypermethylation is negatively correlated with low expression. LAMA3 promotes the invasion, migration and apoptosis of SKOV3DDP. In the future, the mechanism of LAMA3 methylation in ovarian cancer will need to be further studied.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-021-00807-y.

Gut Microbiota and Gynecological Cancers: A Summary of Pathogenetic Mechanisms and Future Directions

Over the past 20 years, important relationships between the microbiota and human health have emerged. A link between alterations of microbiota composition (dysbiosis) and cancer development has been recently demonstrated. In particular, the composition and the oncogenic role of intestinal bacterial flora has been extensively investigated in preclinical and clinical studies focusing on gastrointestinal tumors. Overall, the development of gastrointestinal tumors is favored by dysbiosis as it leads to depletion of antitumor substances (e.g., short-chain fatty acids) produced by healthy microbiota. Moreover, dysbiosis leads to alterations of the gut barrier, promotes a chronic inflammatory status through activation of toll-like receptors, and causes metabolic and hormonal dysregulations. However, the effects of these imbalances are not limited to the gastrointestinal tract and they can influence gynecological tumor carcinogenesis as well. The purpose of this Review is to provide a synthetic update about the mechanisms of interaction between gut microbiota and the female reproductive tract favoring the development of neoplasms. Furthermore, novel therapeutic approaches based on the modulation of microbiota and their role in gynecological oncology are discussed.

The prognostic and diagnostic potential of kallikrein-related peptidases in ovarian cancer

Introduction: Ovarian cancer is one of the deadliest malignancies among women worldwide. The lack of early diagnostic markers fuels an unfavorable prognosis as most patients are at an advanced stage when the disease is diagnosed for the first time. The role of the kallikrein-related peptidase (KLK) family in ovarian cancer progression and prognosis has been thoroughly investigated in various studies. Most of these peptidases are upregulated in ovarian cancer tissue compared to normal ovarian tissue and their expression is linked to overall and progression-free survival (OS/PFS). In this review, we address the clinical relevance of KLKs in ovarian cancer and their diagnostic potential.Areas covered: This review covers the expression and regulation of KLKs in ovarian cancer with focus on the prognostic and diagnostic potential, especially in liquid biopsies.Expert opinion: In ovarian cancer, several kallikrein-related peptidases are markedly expressed in a tissue-specific manner. Tumor-derived protease secretion results in elevated levels in serum and ascites. KLKs may thus serve as potential biomarkers alone or in combination with other serum tumor markers, such as Cancer Antigen 125 (CA125), for early detection and assessment of the prognosis of ovarian cancer patients.

RNF144A suppresses ovarian cancer stem cell properties and tumor progression through regulation of LIN28B degradation via the ubiquitin-proteasome pathway

OBJECTIVE

Cancer stem cells (CSCs) are the main driving force of tumorigenesis, metastasis, recurrence, and drug resistance in epithelial ovarian cancer (EOC). The current study aimed to explore the regulatory effects of ring finger protein 144A (RNF144A), an E3 ubiquitin ligase, in the maintenance of CSC properties and tumor development in EOC.

METHODS

The expressions of RNF144A in EOC tissue samples and cells were examined. The knockdown or overexpression of a target gene was achieved by transfecting EOC cells with short hairpin RNA or adenoviral vectors. A mouse xenograft model was constructed by inoculating nude mice with EOC cells. Co-immunoprecipitation was used to determine the interaction between RNF144A and LIN28B.

RESULTS

Downregulated RNF144A expression was observed in ovarian tumor tissues and EOC cells. Low RNF144A expression was positively associated with poor survival of EOC patients. RNF144A knockdown significantly enhanced sphere formation and upregulated stem cell markers in EOC cells, while RNF144A overexpression prevented EOC cells from acquiring stem cell properties. Also, the upregulation of RNF144A inhibited ovarian tumor growth and aggressiveness in cell culture and mouse xenografts. Further analysis revealed that RNF144A induced LIN28B degradation through ubiquitination in EOC cells. LIN28B upregulation restored the expressions of stem cell pluripotency-associated transcription factors in EOC cells overexpressing RNF144A.

CONCLUSION

Taken together, our findings highlight the therapeutic potential of restoring RNF144A expression and thereby suppressing LIN28B-associated oncogenic signaling for EOC treatment. • Ring finger protein 144A (RNF144A) is downregulated in epithelial ovarian cancer (EOC) tissues and cell lines. • The overexpression of RNF144A prevents EOC cells from acquiring stem cell properties and inhibits ovarian tumor growth. • RNF144A induces LIN28B degradation through ubiquitination in EOC cells. • LIN28B upregulation restores the expressions of stem cell pluripotency-associated transcription factors in EOC cells overexpressing RNF144A.

The Role of Bone Morphogenetic Protein 4 in Ovarian Function and Diseases

Bone morphogenetic proteins (BMPs) are the largest subfamily of the transforming growth factor-β (TGF-β) superfamily. BMP4 is a secreted protein that was originally identified due to its role in bone and cartilage development. Over the past decades, extensive literature has indicated that BMP4 and its receptors are widely expressed in the ovary. Dysregulation of BMP4 expression may play a vital role in follicular development, polycystic ovary syndrome (PCOS), and ovarian cancer. In this review, we summarized the expression pattern of BMP4 in the ovary, focused on the role of BMP4 in follicular development and steroidogenesis, and discussed the role of BMP4 in ovarian diseases such as polycystic ovary syndrome and ovarian cancer. Some studies have shown that the expression of BMP4 in the ovary is spatiotemporal and species specific, but the effects of BMP4 seem to be similar in follicular development of different species. In addition, BMP4 is involved in the development of hyperandrogenemia in PCOS and drug resistance in ovarian cancer, but further research is still needed to clarify the specific mechanisms.

Comparison of dose-dense vs. 3-weekly paclitaxel and carboplatin in the first-line treatment of ovarian cancer in a propensity score-matched cohort

Background

Benefit of carboplatin and dose-dense weekly paclitaxel (ddCT) in first line treatment of ovarian cancer patients has been different in Western and Asian studies. In the present study we compare progression-free survival (PFS) of ddCT to three-weekly carboplatin and paclitaxel (CT) in first-line treatment of ovarian carcinoma in a single institution in a Western population.

Materials and methods

We conducted a retrospective review of medical records from patients with ovarian carcinoma treated in a tertiary cancer center from 2007 to 2018. All patients treated with ddCT or CT in the first-line setting were included. Patients who received first-line bevacizumab were not included. PFS and overall survival (OS) were compared in a propensity score-matched cohort to address selection bias. Patients were matched according to age, ECOG performance status, CA 125, FIGO stage, residual disease, and histological subtype, in a 1:2 ratio.

Results

Five hundred eighty-eight patients were eligible for propensity score matching, the final cohort consisted of 69 patients treated with ddCT and 138 CT group. Baseline characteristics were well-balanced. After a median follow-up of 65.1 months, median PFS was 29.3 vs 20.0 months, favouring ddCT treatment (p = 0.035). In the multivariate cox regression ddCT showed a 18% lower risk of progression (HR 0.82, 95% CI 0.68–0.99, p = 0.04). Overall survival data is immature, but suggested better outcomes for ddCT (not reached versus 78.8 months; p = 0.07).

Conclusion

Our retrospective study has shown superior PFS of ddCT over CT regimen in first-line treatment of ovarian carcinoma in a Western population not treated with bevacizumab.

Recent advancements in therapeutic targeting of the Warburg effect in refractory ovarian cancer: A promise towards disease remission

Epithelial ovarian cancer, the most lethal gynecological malignancy, is diagnosed at advanced stage, recurs and displays chemoresistance to standard chemotherapeutic regimen of taxane/platinum drugs. Despite development of recent therapeutic approaches including poly-ADP ribose polymerase inhibitors, this fatal disease is diagnosed at advanced stage and heralds strategies for early detection and improved treatment. Recent literature suggests that high propensity of ovarian cancer cells to consume and metabolize glucose via glycolysis even in the presence of oxygen (the 'Warburg effect') can significantly contribute to disease progression and chemoresistance and hence, it has been exploited as novel drug target. This review focuses on the molecular cues of aberrant glycolysis as drivers of chemo-resistance and aggressiveness of recurrent ovarian cancer. Furthermore, we discuss the status quo of small molecule inhibition of aerobic glycolysis and significance of metabolic coupling between cancer cells and tumor microenvironment as novel therapeutic interventions against this lethal pathology.

Predictive value of RAD51 on the survival and drug responsiveness of ovarian cancer

Background

Ovarian cancer has greatly endangered and deteriorated female health conditions worldwide. Refinement of predictive biomarkers could enable patient stratification and help optimize disease management.

Methods

RAD51 expression profile, target-disease associations, and fitness scores of RAD51 were analyzed in ovarian cancer using bioinformatic analysis. To further identify its role, gene enrichment analysis was performed, and a regulatory network was constructed. Survival analysis and drug sensitivity assay were performed to evaluate the effect of RAD51 expression on ovarian cancer prognosis. The predictive value of RAD51 was then confirmed in a validation cohort immunohistochemically.

Results

Ovarian cancer expressed more RAD51 than normal ovary. RAD51 conferred ovarian cancer dependency and was associated with ovarian cancer. RAD51 had extensive target-disease associations with various diseases, including ovarian cancer. Genes that correlate with and interact with RAD51 were involved in DNA damage repair and drug responsiveness. High RAD51 expression indicated unfavorable survival outcomes and resistance to platinum, taxane, and PARP inhibitors in ovarian cancer. In the validation cohort (126 patients), high RAD51 expression indicated platinum resistance, and platinum-resistant patients expressed more RAD51. Patients with high RAD51 expression had shorter OS (HR = 2.968, P < 0.0001) and poorer PFS (HR = 2.838, P < 0.0001). RAD51 expression level was negatively correlated with patients’ survival length.

Conclusions

Ovarian cancer had pronounced RAD51 expression and RAD51 conferred ovarian cancer dependency. High RAD51 expression indicated poor survival and decreased drug sensitivity. RAD51 has predictive value in ovarian cancer and can be exploited as a predictive biomarker.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-01953-5.

Spatial cytotoxic and memory T cells in tumor predict superior survival outcomes in patients with high-grade serous ovarian cancer

Although the association between tumor‐infiltrating CD3⁺ T and CD8⁺ T cells and superior survival in high‐grade serous ovarian cancer (HGSOC) has been observed, the different spatial localization of tumor‐infiltrating lymphocytes (TILs) possesses heterogeneous effects. We performed localized measurements in 260 HGSOC from 2 independent cohorts represented in tissue microarray format to determine the localized expression pattern and clinical significance of CD3⁺ T, CD8⁺ T, and CD45RO⁺ cells in HGSOC. Different density of spatial localization of CD3⁺ T, CD8⁺ T, and CD45RO⁺ cells exhibited heterogeneous association with OS. The combination of the center of the tumor and invasive margin localized CD8⁺T cells (CD8^CT&IM) with the same margin localized CD45RO (CD45RO^CT&IM) was the most robust prognostic predictor. Immune score (IS) was constructed by integrating FIGO stage with CD8^CT&IM and CD45RO^IM&CT and had the best prognostic value in HGSOC. The low‐, intermediate‐, and high‐IS groups were observed in 44.7%, 41.6%, and 13.7% of patients, respectively. Low‐IS identified patients were at higher risk of death compared to high‐IS identified patients (HR = 12.426; 95% CI 5.317–29.039, p < 0.001); meanwhile, we evaluate the RMSTs over 10 years of follow‐up and obtained RMST values of 104.09 months (95% CI 96.31–111.87 months) in the high‐IS group, 75.26 months (95% CI 59.92–90.60 months) in the intermediate‐IS group, and 48.68 months (95%CI 38.82–58.54 months) in the low‐IS group. In general, spatial localization can modulate the clinical effects of TILs in HGSOC. Thus, the spatial expression of CD8 and CD45RO could aid clinicians to determine the follow‐up plan of patients with HGSOC.

MRPL15 is a novel prognostic biomarker and therapeutic target for epithelial ovarian cancer

PURPOSE

To analyze the role of six human epididymis protein 4 (HE4)-related mitochondrial ribosomal proteins (MRPs) in ovarian cancer and selected MRPL15, which is most closely related to the tumorigenesis and prognosis of ovarian cancer, for further analyses.

METHODS

Using STRING database and MCODE plugin in Cytoscape, six MRPs were identified among genes that are upregulated in response to HE4 overexpression in epithelial ovarian cancer cells. The Cancer Genome Atlas (TCGA) ovarian cancer, GTEX, Oncomine, and TISIDB were used to analyze the expression of the six MRPs. The prognostic impact and genetic variation of these six MRPs in ovarian cancer were evaluated using Kaplan-Meier Plotter and cBioPortal, respectively. MRPL15 was selected for immunohistochemistry and GEO verification. TCGA ovarian cancer data, gene set enrichment analysis, and Enrichr were used to explore the mechanism of MRPL15 in ovarian cancer. Finally, the relationship between MRPL15 expression and immune subtype, tumor-infiltrating lymphocytes, and immune regulatory factors was analyzed using TCGA ovarian cancer data and TISIDB.

RESULTS

Six MRPs (MRPL10, MRPL15, MRPL36, MRPL39, MRPS16, and MRPS31) related to HE4 in ovarian cancer were selected. MRPL15 was highly expressed and amplified in ovarian cancer and was related to the poor prognosis of patients. Mechanism analysis indicated that MRPL15 plays a role in ovarian cancer through pathways such as the cell cycle, DNA repair, and mTOR 1 signaling. High expression of MRPL15 in ovarian cancer may be associated with its amplification and hypomethylation. Additionally, MRPL15 showed the lowest expression in C3 ovarian cancer and was correlated with proliferation of CD8⁺ T cells and dendritic cells as well as TGFβR1 and IDO1 expression.

CONCLUSION

MRPL15 may be a prognostic indicator and therapeutic target for ovarian cancer. Because of its close correlation with HE4, this study provides insights into the mechanism of HE4 in ovarian cancer.

Synergistic effect of Chloroquine and Panobinostat in ovarian cancer through induction of DNA damage and inhibition of DNA repair

Ovarian cancer (OC) is the deadliest gynecologic malignancy, which is mainly due to late-stage diagnosis and chemotherapy resistance. Therefore, new and more effective treatments are urgently needed. The in vitro effects of Panobinostat (LBH), a histone deacetylase inhibitor that exerts pleiotropic antitumor effects but induces autophagy, in combination with Chloroquine (CQ), an autophagy inhibitor that avoid this cell survival mechanism, were evaluated in 4 OC cell lines. LBH and CQ inhibited ovarian cancer cell proliferation and induced apoptosis, and a strong synergistic effect was observed when combined. Deeping into their mechanisms of action we show that, in addition to autophagy modulation, treatment with CQ increased reactive oxygen species (ROS) causing DNA double strand breaks (DSBs), whereas LBH inhibited their repair by avoiding the correct recruitment of the recombinase Rad51 to DSBs. Interestingly, CQ-induced DSBs and cell death caused by CQ/LBH combination were largely abolished by the ROS scavenger N-Acetylcysteine, revealing the critical role of DSB generation in CQ/LBH-induced lethality. This role was also manifested by the synergy found when we combined CQ with Mirin, a well-known homologous recombination repair inhibitor. Altogether, our results provide a rationale for the clinical investigation of CQ/LBH combination in ovarian cancer.

[Low-grade serous ovarian carcinoma: A retrospective study on 34 complete cytoreductive surgeries]

AIM OF THE STUDY

Low-grade serous ovarian cancer is a distinct, slow-growing entity that affects mainly young women. The objective of this study was to describe the clinical characterisitics and survival outcomes of a population of patients suffering from advanced stage CSBG.

PATIENTS AND METHODS

A retrospective study was carried out in patients with advanced stage ovarian CSBG (FIGO IIIb-IV) who had complete macroscopic cytoreductive surgery, at Gustave Roussy Institut, Villejuif, between 2004 and 2017.

RESULTS

Thirty-four patients were included, who were mainly young women (mean age 41.3 years), diagnosed at FIGO stage IIIC (91 %). The median follow-up was 41 months. Neoadjuvant chemotherapy was administered in 16 patients (47.1 %), and complete response never occurred. Upper abdominal surgical procedures were necessary in 90 % of cases and a bowel resection was performed in more than 80 % of cases. Over 90 % of patients received adjuvant chemotherapy followed by maintenance treatment with bevacizumab in over 40 % of cases. During follow-up, 9 (26 %) deaths occurred. Five-year overall survival was 70 % and disease-free survival was 20 %.

CONCLUSION

CSBG of the ovary has a low chemosensitivity and requires maximum surgical management, which should be performed in expert centers.

RHPN1‑AS1 promotes ovarian carcinogenesis by sponging miR‑485‑5p and releasing TPX2 mRNA

Long non-coding RNAs (lncRNAs) play a crucial role in cancer development. However, researchers have yet to identify the underlying association between lncRNAs and ovarian cancer (OC). The aim of the present study was to examine the effect of lncRNA RHPN1-AS1 (RHPN1-AS1) on OC cells and tissues. Reverse transcriptase-quantitative PCR (RT-qPCR) was utilized to quantify RHPN1-AS1, miR-485-5p, and TPX2 mRNA expression in samples with OC. Luciferase-reporter assay, RNA immunoprecipitation (RIP) assay, and RNA pull-down assay were then employed to validate the target relationship among RHPN1-AS1, miR-485-5p and TPX2. Cell Counting Kit-8, BrdU, wound-healing, cell-adhesion, and flow cytometry assays were also employed to assess cell viability, proliferation, migration, adhesion and apoptosis, respectively, in SKOV3 and OVCAR3 cell lines. Findings revealed that RHPN1-AS1 demonstrated a higher expression level in OC cell lines and tissues. In addition, RHPN1-AS1 enhanced the adhesion, proliferation and migration of OC cell lines but decreased apoptosis of OC cells. It was also observed that the relationship between RHPN1-AS1 and miR-485-5p was negative and that RHPN1-AS1 could sponge miR-485-5p to regulate the proliferation, apoptosis, adhesion, and migration abilities of OC cells. Moreover, TPX2 was targeted by miR-485-5p and was significantly overexpressed in OC cell lines and tissues. Experimental investigations also revealed that TPX2 promoted the proliferation, adhesion, and migration of OC cells but suppressed the apoptosis of SKOV3 and OVCAR3 cells. In summary, RHPN1-AS1 played a tumor promotive role by sponging miR-485-5p to increase TPX2 expression in OC tumorigenesis.

Cell therapies in ovarian cancer

Epithelial ovarian cancer (EOC) is the most important cause of gynecological cancer-related mortality. Despite improvements in medical therapies, particularly with the incorporation of drugs targeting homologous recombination deficiency, EOC survival rates remain low. Adoptive cell therapy (ACT) is a personalized form of immunotherapy in which autologous lymphocytes are expanded, manipulated ex vivo, and re-infused into patients to mediate cancer rejection. This highly promising novel approach with curative potential encompasses multiple strategies, including the adoptive transfer of tumor-infiltrating lymphocytes, natural killer cells, or engineered immune components such as chimeric antigen receptor (CAR) constructs and engineered T-cell receptors. Technical advances in genomics and immuno-engineering have made possible neoantigen-based ACT strategies, as well as CAR-T cells with increased cell persistence and intratumoral trafficking, which have the potential to broaden the opportunity for patients with EOC. Furthermore, dendritic cell-based immunotherapies have been tested in patients with EOC with modest but encouraging results, while the combination of DC-based vaccination as a priming modality for other cancer therapies has shown encouraging results. In this manuscript, we provide a clinically oriented historical overview of various forms of cell therapies for the treatment of EOC, with an emphasis on T-cell therapy.

Mucin expression, epigenetic regulation and patient survival: A toolkit of prognostic biomarkers in epithelial cancers

Twenty mucin genes have been identified and classified in two groups (encoding secreted and membrane-bound proteins). Secreted mucins participate in mucus formation by assembling a 3-dimensional network via oligomerization, whereas membrane-bound mucins are anchored to the outer membrane mediating extracellular interactions and cell signaling. Both groups have been associated with carcinogenesis progression in epithelial cancers, and are therefore considered as potential therapeutic targets. In the present review, we discuss the link between mucin expression patterns and patient survival and propose mucins as prognosis biomarkers of epithelial cancers (esophagus, gastric, pancreatic, colorectal, lung, breast or ovarian cancers). We also investigate the relationship between mucin expression and overall survival in the TCGA dataset. In particular, epigenetic mechanisms regulating mucin gene expression, such as aberrant DNA methylation and histone modification, are interesting as they are also associated with diagnosis or prognosis significance. Indeed, mucin hypomethylation has been shown to be associated with carcinogenesis progression and was linked to prognosis in colon cancer or pancreatic cancer patients. Finally we describe the relationship between mucin expression and non-coding RNAs that also may serve as biomarkers. Altogether the concomitant knowledge of specific mucin-pattern expression and epigenetic regulation could be translated as biomarkers with a better specificity/sensitivity performance in several epithelial cancers.

Organoids of the Female Reproductive Tract: Innovative Tools to Study Desired to Unwelcome Processes

The pelviperineal organs of the female reproductive tract form an essential cornerstone of human procreation. The system comprises the ectodermal external genitalia, the Müllerian upper-vaginal, cervical, endometrial and oviductal derivatives, and the endodermal ovaries. Each of these organs presents with a unique course of biological development as well as of malignant degeneration. For many decades, various preclinical in vitro models have been employed to study female reproductive organ (patho-)biology, however, facing important shortcomings of limited expandability, loss of representativeness and inadequate translatability to the clinic. The recent emergence of 3D organoid models has propelled the field forward by generating powerful research tools that in vitro replicate healthy as well as diseased human tissues and are amenable to state-of-the-art experimental interventions. Here, we in detail review organoid modeling of the different female reproductive organs from healthy and tumorigenic backgrounds, and project perspectives for both scientists and clinicians.

Analysis of the association between KIN17 expression and the clinical features/prognosis of epithelial ovarian cancer, and the effects of KIN17 in SKOV3 cells

DNA double-strand breaks (DSBs) are an important mechanism of chemotherapy in epithelial ovarian cancer (EOC). Kin17 DNA and RNA binding protein (KIN17) serves a crucial role in DSB repair. In the present study, the association between KIN17 and EOC, and the effects of KIN17 on EOC cells in vitro were evaluated. A bioinformatics method was used to determine the mRNA expression levels of KIN17 in EOC and its association with EOC prognosis including overall survival (OS) and progression free survival (PFS) time. Western blotting and immunohistochemical staining were used to evaluate the expression levels of KIN17 in EOC samples. Kaplan-Meier and Cox regression analyses were utilized to analyze risk factors for the OS of patients with EOC. A Cell Counting Kit-8 assay was performed to explore the roles of KIN17 in SKOV3 cells. Both the transcription and expression of KIN17 were upregulated in EOC tissues. Furthermore, the OS of patients with EOC with high mRNA expression levels of KIN17 was shorter than that of patients with EOC with low expression levels. High KIN17 expression was an independent risk factor for EOC prognosis. Furthermore, KIN17 knockdown inhibited the proliferation of SKOV3 cells, enhanced the sensitivity of the cells to cisplatin and inhibited the migration ability of the cells. These results suggested that KIN17 may act as an ideal candidate for therapy and as a prognostic biomarker of EOC, although the underlying mechanisms require further exploration.

Development of Aptamer-Based Molecular Tools for Rapid Intraoperative Diagnosis and In Vivo Imaging of Serous Ovarian Cancer

Diagnosis and treatment of ovarian cancer are based on intraoperative pathology and debulking surgery. The development of a novel molecular tool is significant for rapid intraoperative pathologic diagnosis, which instructs the decision-making on excision surgery and effective chemotherapy. In this work, we represent a DNA aptamer named mApoc46, which is generated from cell-SELEX by targeting patient-derived primary serous ovarian cancer (pSOC) cells. An average dissociation constant (K_d) was determined to be 0.15 ± 0.05 μM by flow cytometry. The mApoc46 aptamer displays a robust specificity to pSOC cells. Labeled with FAM, mApoc46 can selectively stain living pSOC cells in 30 min without staining commercial OC cell lines and cell lines associated with other cancers. Interestingly, FAM-mApoc46 displayed superb selectivity toward high-grade serous ovarian cancer (HG-SOC) tissues in frozen sections against low-grade SOC, ovarian borderline tumor, other nonepithelial ovarian tumors, and healthy ovarian tissue. These results lead to a potential application in the identification of OCs' histological subtypes during operation. In the patient-derived tumor xenograft NCG mice model, Cy5-labeled mApoc46 was found to accumulate at the tumor area and served as an in vivo imaging probe. The mApoc46 probe shows a robust and stable performance to visualize SOC tumors in the body. Therefore, aptamer mApoc46 holds great potential in rapid intraoperative detection, pathological diagnosis, fluorescence image-guided cancer surgery, and targeted drug delivery and therapy.

Pentraxin 3 is a diagnostic and prognostic marker for ovarian epithelial cancer patients based on comprehensive bioinformatics and experiments

BACKGROUND

Ovarian epithelial cancer is one of the leading malignant tumors in gynecology and lacks effective diagnostic and prognostic markers. Our study aims to screen and verify ovarian epithelial cancer biomarkers.

METHODS

GSE18520 and GSE26712 were downloaded from the GEO database. The "limma" and "WGCNA" packages were used to explore hub genes. The Kaplan-Meier Plotter database was used for survival analysis of the hub genes. Immunohistochemical analysis was used to identify the expression level of Pentraxin 3 in ovarian epithelial cancer samples.

RESULTS

In this study, we integrated and analyzed two datasets, GSE18520 and GSE26712, and a total of 238 differentially expressed genes (DEGs) were screened out. Enrichment analysis showed that these DEGs were related to collagen-containing extracellular matrix and other pathways. Further application of WGCNA (weighted gene coexpression network analysis) identified 15 gene modules, with the purple module showing the highest correlation with ovarian epithelial cancer. Twenty-five genes were shared between the purple module and DEGs, 13 genes were related to the prognosis of ovarian epithelial cancer patients, and the PTX3 gene had the highest hazardous risk (HR) value. We performed immunohistochemical analyses on the 255 Pentraxin-3 (PTX3)-based clinical samples. PTX3 was found to be overexpressed in ovarian epithelial cancer and related to the degree of differentiation. The Cox proportional hazard model indicates that high PTX3 expression is an independent risk factor for the prognosis of ovarian epithelial cancer patients.

CONCLUSIONS

In conclusion, through WGCNA and a series of comprehensive bioinformatics analyses, PTX3 was first identified as a novel diagnostic and prognostic biomarker for ovarian epithelial cancer.

A Novel Defined Risk Signature of the Ferroptosis-Related Genes for Predicting the Prognosis of Ovarian Cancer

Ferroptosis is an iron-dependent, regulated form of cell death, and the process is complex, consisting of a variety of metabolites and biological molecules. Ovarian cancer (OC) is a highly malignant gynecologic tumor with a poor survival rate. However, the predictive role of ferroptosis-related genes in ovarian cancer prognosis remains unknown. In this study, we demonstrated that the 57 ferroptosis-related genes were expressed differently between ovarian cancer and normal ovarian tissue, and based on these genes, all OC cases can be well divided into 2 subgroups by applying consensus clustering. We utilized the least absolute shrinkage and selection operator (LASSO) cox regression model to develop a multigene risk signature from the TCGA cohort and then validated it in an OC cohort from the GEO database. A 5-gene signature was built and reveals a favorable predictive efficacy in both TCGA and GEO cohort (P < 0.001 and P = 0.03). The GO and KEGG analysis revealed that the differentially expressed genes (DEGs) between the low- and high-risk subgroup divided by our risk model were associated with tumor immunity, and lower immune status in the high-risk group was discovered. In conclusion, ferroptosis-related genes are vital factors predicting the prognosis of OC and could be a novel potential treatment target.

The PROMova study comparing active and passive use of patient-reported outcome measures in ovarian cancer follow-up: effect on patient-perceived involvement, satisfaction with care, and usefulness

BACKGROUND

Patients with ovarian cancer often experience substantial health problems and side effects resulting in reduced quality of life (QoL). Different models of using patient-reported outcome measures (PROMs) during follow-up may improve the quality of care. This national, multicenter observational study investigated the effect of active use of PROMs on patient-perceived involvement, satisfaction with care, unmet needs, and QoL during follow-up of ovarian cancer.

MATERIAL AND METHODS

Ovarian cancer patients were recruited at the end of primary treatment at eight centers in Denmark. During 18 months of follow-up patients repeatedly completed European Organization for Research and Treatment of Cancer (EORTC) questionnaires covering health related QoL and symptoms. At the sites using PROMs actively (ACT), the clinician had access to an overview of the patient's scores during the clinical encounter. Clinicians using PROMs passively were alerted in case of severe development of symptoms. Following each encounter, patients evaluated their health service experience by completing the CollaboRATE scale of involvement in decision making, the Patient Experience Questionnaire, and ad hoc questions covering patient-perceived usefulness of the PROMs.

RESULTS

A total of 223 patients were enrolled, i.e., 168 (75.3%) at five sites using ACT and 53 (23.8%) at three sites using them passively. We found no statistically significant difference in involvement in the decision making, satisfaction with care, unmet needs, and QoL between the two groups. The majority of patients found it useful to complete the PROMs, although it did not seem to significantly support them in raising issues with the oncologist.

CONCLUSION

Active use of PROMs did not improve patients' experience of involvement in follow-up care as compared to passive use.

HSP90 identified by a proteomic approach as druggable target to reverse platinum resistance in ovarian cancer

Acquired resistance to platinum (Pt)-based therapies is an urgent unmet need in the management of epithelial ovarian cancer (EOC) patients. Here, we characterized by an unbiased proteomics method three isogenic EOC models of acquired Pt resistance (TOV-112D, OVSAHO, and MDAH-2774). Using this approach, we identified several differentially expressed proteins in Pt-resistant (Pt-res) compared to parental cells and the chaperone HSP90 as a central hub of these protein networks. Accordingly, up-regulation of HSP90 was observed in all Pt-res cells and heat-shock protein 90 alpha isoform knockout resensitizes Pt-res cells to cisplatin (CDDP) treatment. Moreover, pharmacological HSP90 inhibition using two different inhibitors [17-(allylamino)-17-demethoxygeldanamycin (17AAG) and ganetespib] synergizes with CDDP in killing Pt-res cells in all tested models. Mechanistically, genetic or pharmacological HSP90 inhibition plus CDDP -induced apoptosis and increased DNA damage, particularly in Pt-res cells. Importantly, the antitumor activities of HSP90 inhibitors (HSP90i) were confirmed both ex vivo in primary cultures derived from Pt-res EOC patients ascites and in vivo in a xenograft model. Collectively, our data suggest an innovative antitumor strategy, based on Pt compounds plus HSP90i, to rechallenge Pt-res EOC patients that might warrant further clinical evaluation.

Low Expression of Circular RNA hsa_circ_0078607 Predicts Poor Prognosis in High-Grade Serous Ovarian Cancer

Objective

Recent studies have shown that circRNAs participate in ovarian cancer progression and act as potential biomarkers for ovarian cancer diagnosis and prognosis. In the present study, we aimed to investigate the expression pattern and prognostic significance of circ_0078607 in high-grade serous ovarian cancer (HGSOC).

Methods

The expression of circ_0078607 was detected by quantitative real-time polymerase chain reaction (qRT-PCR) in 49 cases of HGSOC. Clinical data of patients with HGSOC were retrospectively collected, and those patients were divided according to their expression of circ_0078607. Correlation between circ_0078607 and clinical features as well as the prognosis in patients with HGSOC was analyzed. t-test and chi-square test were used to compare continuous and categorical variables. The Cox hazard regression model was used to assess prognostic factors. Both progression-free survival (PFS) and overall survival (OS) curves were generated by Kaplan-Meier method.

Results

The expression of circ_0078607 was significantly downregulated in ovarian cancer tissues compared with adjacent non-cancerous tissues. Besides, patients with low circ_0078607 expression exhibited parameters associated with poor prognosis, including advanced FIGO stage and higher serum CA125 level. Kaplan-Meier survival curve analysis showed that patients with low circ_0078607 expression had shorter PFS and OS. Cox regression analysis showed that low expression of circ_0078607 was a predictor for poor PFS and OS in HGSOC patients.

Conclusion

Low expression of circ_0078607 might be an adverse prognostic indicator for HGSOC.

Prognostic Evidence of the miRNA-Based Ovarian Cancer Signature MiROvaR in Independent Datasets

Simple Summary

Epithelial ovarian cancers (EOC) have an unpredictable frequent recurrence often associated with incurable chemo-resistant disease. Basing on the miRNA expression profile of 892 EOC patients, we previously developed a 35 miRNA-based classifier, MiROvaR, able to predict EOC risk of early relapse. Further independent analysis of prediction accuracy represents a crucial step in the test-validation phase. Here we exploited an external and independently collected, handled and profiled EOC cohort, to challenge MirovaR accuracy. Our analysis confirmed the MiROvaR prognostic power, thus opening the way to its prospective validation as a clinical grade assay entering into clinical practice to help in the refinement of therapeutic intervention for high risk EOC patients.

Abstract

Epithelial ovarian cancer (EOC) remains the second most common cause of gynecological cancer deaths. To improve patients’ outcomes, we still need reliable biomarkers of early relapse, of which external independent validation is a crucial process. Our previously established prognostic signature, MiROvaR, including 35 microRNAs (miRNA) able to stratify EOC patients for their risk of relapse, was challenged on a new independent cohort of 197 EOC patients included in the Pelvic Mass Study whose miRNA profile was made publically available, thus resulting in the only accessible database aside from the EOC TCGA collection. Following accurate data matrix adjustment to account for the use of different miRNA platforms, MiROvaR confirmed its ability to discriminate early relapsing patients. The model’s original cutoff separated 156 (79.2%) high- and 41 (20.8%) low-risk patients with median progression free survival (PFS) of 16.3 months and not yet reached (NYR), respectively (hazard ratio (HR): 2.42–95% Confidence Interval (CI) 1.49–3.93; Log-rank p = 0.00024). The MiROvaR predictive accuracy (area under the curve (AUC) = 0.68; 95% Cl 0.57–0.79) confirms its prognostic value. This external validation in a totally independently collected, handled and profiled EOC cohort suggests that MiROvaR is a strong and reliable biomarker of EOC early relapse, warranting prospective validation.

Cellular models of development of ovarian high-grade serous carcinoma: A review of cell of origin and mechanisms of carcinogenesis

High-grade serous carcinoma (HGSC) is the most common and malignant histological type of epithelial ovarian cancer, the origin of which remains controversial. Currently, the secretory epithelial cells of the fallopian tube are regarded as the main origin and the ovarian surface epithelial cells as a minor origin. In tubal epithelium, these cells acquire TP53 mutations and expand to a morphologically normal 'p53 signature' lesion, transform to serous tubal intraepithelial carcinoma and metastasize to the ovaries and peritoneum where they develop into HGSC. This shifting paradigm of the main cell of origin has revolutionarily changed the focus of HGSC research. Various cell lines have been derived from the two cellular origins by acquiring immortalization via overexpression of hTERT plus disruption of TP53 and the CDK4/RB pathway. Malignant transformation was achieved by adding canonical driver mutations (such as gain of CCNE1) revealed by The Cancer Genome Atlas or by noncanonical gain of YAP and miR181a. Alternatively, because of the extreme chromosomal instability, spontaneous transformation can be achieved by long passage of murine immortalized cells, whereas in humans, it requires ovulatory follicular fluid, containing regenerating growth factors to facilitate spontaneous transformation. These artificially and spontaneously transformed cell systems in both humans and mice have been widely used to discover carcinogens, oncogenic pathways and malignant behaviours in the development of HGSC. Here, we review the origin, aetiology and carcinogenic mechanism of HGSC and comprehensively summarize the cell models used to study this fatal cancer having multiple cells of origin and overt genomic instability.

Circular RNA ABCB10 promotes cell proliferation and invasion, but inhibits apoptosis via regulating the microRNA‑1271‑mediated Capn4/Wnt/β‑catenin signaling pathway in epithelial ovarian cancer

Circular RNA ABCB10 (circ-ABCB10) modulates cellular functions and microRNA (miR)-1271 in epithelial ovarian cancer (EOC). The present study aimed to investigate the interaction between circ-ABCB10 and miR-1271 in regulating EOC cellular function and the calpain small subunit 1 (Capn4)/Wnt/β-catenin signaling pathway. circ-ABCB10 and miR-1271 expression levels were detected in EOC cells (OVCAR3, UWB1.289, SKOV3 and CAOV3) and normal ovarian epithelial cells (IOSE80) via reverse-transcription quantitative PCR. SKOV3 cells were transfected with control short hairpin (sh)RNA plasmids, control inhibitor, circ-ABCB10 shRNA plasmids and miR-1271 inhibitor. UWB1.289 cells were transfected with control overexpression plasmids, control mimic, circ-ABCB10 overexpression plasmids and miR-1271 mimic. Subsequently, cell proliferation, apoptosis, invasion and the Capn4/Wnt/β-catenin signaling pathway were assessed. In addition, a luciferase activity assay was performed. circ-ABCB10 expression was significantly increased in OVCAR3, SKOV3 and CAOV3 cells compared with IOSE80 cells, but was not significantly altered in UWB1.289 cells. miR-1271 expression was significantly decreased in OVCAR3, UWB1.289, SKOV3 and CAOV3 cells compared with IOSE80 cells. In both SKOV3 and UWB1.289 cells, circ-ABCB10 negatively regulated miR-1271, whereas miR-1271 did not affect circ-ABCB10. Furthermore, circ-ABCB10 enhanced cell proliferation, invasion and the Capn4/Wnt/β-catenin signaling pathway, but inhibited cell apoptosis, whereas miR-1271 suppressed cell proliferation, invasion and the Capn4/Wnt/β-catenin signaling pathway, but facilitated cell apoptosis. Moreover, miR-1271 attenuated the proproliferative, proinvasive and antiapoptotic effects of circ-ABCB10, and reversed the positive regulation of circ-ABCB10 on the Capn4/Wnt/β-catenin signaling pathway. Besides, the luciferase activity assay indicated that circ-ABCB10 directly bound to miR-1271. In conclusion, the present study indicated that circ-ABCB10 promoted cell proliferation and invasion, and suppressed apoptosis by regulating the miR-1271-mediated Capn4/Wnt/β-catenin signaling pathway in EOC.

Identification and Development of Subtypes With Poor Prognosis in Pan-Gynecological Cancer Based on Gene Expression in the Glycolysis-Cholesterol Synthesis Axis

Objective: Metabolic reprogramming is an important biomarker of cancer. Metabolic adaptation driven by oncogenes allows tumor cells to survive and grow in a complex tumor microenvironment. The heterogeneity of tumor metabolism is related to survival time, somatic cell-driven gene mutations, and tumor subtypes. Using the heterogeneity of different metabolic pathways for the classification of gynecological pan-cancer is of great significance for clinical decision-making and prognosis prediction. Methods: RNA sequencing data for patients with ovarian, cervical, and endometrial cancer were downloaded from The Cancer Genome Atlas database. Genes related to glycolysis and cholesterol were extracted and clustered coherently by using ConsensusClusterPlus. The mutations and copy number variations in different subtypes were compared, and the immune scores of the samples were evaluated. The limma R package was used to identify differentially expressed genes between subtypes, and the WebGestaltR package (V0.4.2) was used to conduct Kyoto Encyclopedia of Genes and Genomes pathway and Gene Ontology functional enrichment analyses. A risk score model was constructed based on multivariate Cox analysis. Prognostic classification efficiency was analyzed by using timeROC, and internal and external cohorts were used to verify the robustness of the model. Results: Based on the expression of 11 glycolysis-related genes and seven cholesterol-related genes, 1,204 samples were divided into four metabolic subtypes (quiescent, glycolysis, cholesterol, and mixed). Immune infiltration scores showed significant differences among the four subtypes. Survival analysis showed that the prognosis of the cholesterol subtype was better than that of the quiescent subtype. A nine-gene signature was constructed based on differentially expressed genes between the cholesterol and quiescent subtypes, and it was validated by using an independent cohort of the International Cancer Genome Consortium. Compared with existing models, our nine-gene signature had good prediction performance. Conclusion: The metabolic classification of gynecological pan-cancer based on metabolic reprogramming may provide an important basis for clinicians to choose treatment options, predict treatment resistance, and predict patients' clinical outcomes.

Triptolide inhibits JAK2/STAT3 signaling and induces lethal autophagy through ROS generation in cisplatin‑resistant SKOV3/DDP ovarian cancer cells

Advanced and recurrent ovarian cancer has a poor prognosis and is frequently resistant to numerous therapeutics; thus, safe and effective drugs are needed to combat this disease. Previous studies have demonstrated that triptolide (TPL) exhibits anticancer and sensitization effects against cisplatin (DDP)-resistant ovarian cancer both in vitro and in vivo by inducing apoptosis; however, the involvement of autophagy induced by TPL in resistant ovarian carcinoma remains unclear. In the present study, the results revealed that TPL induced autophagy to facilitate SKOV3/DDP ovarian cancer cell death. The xenograft experiment revealed that the autophagy inhibitor CQ significantly reduced TPL-mediated chemosensitization and tumor growth inhibition. Mechanically, TPL-induced autophagy in SKOV3/DDP cells was associated with the induction of ROS generation and inhibition of the Janus kinase 2 (JAK2)/signal transducer and activator of transcription-3 (STAT3) pathway. The inhibitory effect of TPL on the JAK2/STAT3 pathway could be restored in the presence of the antioxidant NAC. Furthermore, it was further determined that TPL disrupted the interaction between Mcl-1 and Beclin1, which was prevented by the JAK2/STAT3 signaling activator IL-6. Overall, the present results revealed a novel molecular mechanism whereby TPL induced lethal autophagy through the ROS-JAK2/STAT3 signaling cascade in SKOV3/DDP cells. The present study has provided the groundwork for future application of TPL in the treatment of ovarian cancer.

Growth differentiation factor-15 promotes immune escape of ovarian cancer via targeting CD44 in dendritic cells

Immune escape is the main cause of the low response rate to immunotherapy for cancer, including ovarian cancer. Growth differentiation factor-15 (GDF-15) inhibits immune cell function. However, only few reports described the mechanism. Therefore, the aim of this study was to investigate the mechanism of immune escape regulated by GDF-15 in ovarian cancer. Ovarian cancer patients and healthy women were enrolled in this study. Immunohistochemistry and ELISA were performed to measure GDF-15 expression. Immunoprecipitation combined with mass spectrometry, surface plasmon resonance, and co-immunoprecipitation assay were used to evaluate the interaction between GDF-15 and the surface molecules of DCs. Immunofluorescence analysis, flow cytometry and transwell assay were used to evaluate additional effects of GDF-15 on DCs. The results showed that GDF-15 expression was higher in the ovarian cancer patients compared to that in the healthy women. The TIMER algorithm revealed that highly GDF-15 expression is associated with immune DC infiltration in immunoreactive high-grade serous carcinoma. A further study showed that GDF-15 suppressed DCs maturation, as well as IL-12p40 and TNF-α secretion, the length and number of protrusions and the migration. More importantly, CD44 in the surface of DCs interacted with GDF-15. The overexpression of CD44 in DCs resulted in the suppression of the inhibitory effect of GDF-15 on the length and number of DC synapses. In DCs overexpressing CD44 the inhibition of GDF-15 on the expression of CD11c, CD83 and CD86 was decreased, while in DCs with a knockdown of CD44 the inhibition was further enhanced. Knockdown of CD44 in DCs enhanced the inhibitory effect of GDF-15 on DC migration, while the overexpression of CD44 inhibited the inhibitory effect of GDF-15 on DC migration. In conclusion, the present study suggested that GDF-15 might facilitate ovarian cancer immune escape by interacting with CD44 in DCs to inhibit their function.

ClC-3 promotes paclitaxel resistance via modulating tubulins polymerization in ovarian cancer cells

Epithelial ovarian cancers (EOC) present as malignant tumors with high mortality in the female reproductive system diseases. Acquired resistance to paclitaxel (PTX), one of the first-line treatment of EOC, remains a therapeutic challenge. ClC-3, a member of the voltage-gated Cl^- channels, plays an essential role in a variety of cellular activities, including chemotherapeutic resistance. Here, we demonstrated that the protein expression and channel function of ClC-3 was upregulated in PTX resistance A2780/PTX cells compared with its parental A2780 cells. The silence of ClC-3 expression by siRNA in A2780/PTX cells partly recovered the PTX sensitivity through restored the G2/M arrest and resumed the chloride channel blocked. ClC-3 siRNA both inhibited the expression of ClC-3 and β-tubulin, whereas the β-tubulin siRNA reduced the expression of itself only, without affecting the expression of ClC-3. Moreover, treatment of ClC-3 siRNA in A2780/PTX cells increased the polymerization ratio of β-tubulin, and the possibility of proteins interaction between ClC-3 and β-tubulin was existing. Take together, the over-expression of ClC-3 protein in PTX-resistance ovarian cancer cells promotes the combination of ClC-3 and β-tubulin, which in turn increase the ration of free form and decrease the quota of the polymeric form of β-tubulin, and finally reduce the sensitivity to PTX. Our findings elucidated a novel function of ClC-3 in regulating PTX resistance and ClC-3 could serve as a potential target to overcome the PTX resistance ovarian cancer.

The Role of Myeloid-Derived Suppressor Cells (MDSCs) in the Development and/or Progression of Endometriosis-State of the Art

Endometriosis (EMS) is a common gynecological disease characterized by the presence of endometrial tissue outside the uterus. Approximately 10% of women around the world suffer from this disease. Recent studies suggest that endometriosis has potential to transform into endometriosis-associated ovarian cancer (EAOC). Endometriosis is connected with chronic inflammation and changes in the phenotype, activity, and function of immune cells. The underlying mechanisms include quantitative and functional disturbances of neutrophils, monocytes/macrophages (MO/MA), natural killer cells (NK), and T cells. A few reports have shown that immunosuppressive cells such as regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) may promote the progression of endometriosis. MDSCs are a heterogeneous population of immature myeloid cells (dendritic cells, granulocytes, and MO/MA precursors), which play an important role in the development of immunological diseases such as chronic inflammation and cancer. The presence of MDSCs in pathological conditions correlates with immunosuppression, angiogenesis, or release of growth factors and cytokines, which promote progression of these diseases. In this paper, we review the impact of MDSCs on different populations of immune cells, focusing on their immunosuppressive role in the immune system, which may be related with the pathogenesis and/or progression of endometriosis and its transformation into ovarian cancer.

Splicing factor USP39 promotes ovarian cancer malignancy through maintaining efficient splicing of oncogenic HMGA2

Aberrant expression of splicing factors was found to promote tumorigenesis and the development of human malignant tumors. Nevertheless, the underlying mechanisms and functional relevance remain elusive. We here show that USP39, a component of the spliceosome, is frequently overexpressed in high-grade serous ovarian carcinoma (HGSOC) and that an elevated level of USP39 is associated with a poor prognosis. USP39 promotes proliferation/invasion in vitro and tumor growth in vivo. Importantly, USP39 was transcriptionally activated by the oncogene protein c-MYC in ovarian cancer cells. We further demonstrated that USP39 colocalizes with spliceosome components in nuclear speckles. Transcriptomic analysis revealed that USP39 deletion led to globally impaired splicing that is characterized by skipped exons and overrepresentation of introns and intergenic regions. Furthermore, RNA immunoprecipitation sequencing showed that USP39 preferentially binds to exon-intron regions near 5' and 3' splicing sites. In particular, USP39 facilitates efficient splicing of HMGA2 and thereby increases the malignancy of ovarian cancer cells. Taken together, our results indicate that USP39 functions as an oncogenic splicing factor in ovarian cancer and represents a potential target for ovarian cancer therapy.