New strategies in ovarian cancer: translating the molecular complexity of ovarian cancer into treatment advances

Mirvetuximab soravtansine in platinum-resistant recurrent ovarian cancer with high folate receptor-alpha expression: a cost-effectiveness analysis

OBJECTIVE

Mirvetuximab soravtansine (MIRV), a new antibody-drug conjugate, versus the investigator's choice of chemotherapy (IC) was the first treatment to demonstrate benefits for progression-free and overall survival in platinum-resistant recurrent ovarian cancer (PROC) with high folate receptor-alpha (high-FRα) expression. Efficacy, safety, and economic effectiveness make MIRV the new standard of care for these patients.

METHODS

Based on patients and clinical parameters from MIRASOL (GOG 3045/ENGOT-ov55) phase III randomized controlled trials, the Markov model with a 20-year time horizon was established to evaluate the cost and efficacy of MIRV and IC for PROC with high-FRα expression, considering the bevacizumab-pretreated situation from the American healthcare system. Total cost, life-years (LYs), quality-adjusted life-years (QALYs), incremental cost-effectiveness ratio (ICER), and incremental net health benefits were the main outcome indicators and compared with willingness-to-pay threshold of $100,000/QALY. Sensitivity and scenario analyses were conducted.

RESULTS

Compared with the IC, MIRV was associated with incremental costs of $538,251, $575,674, and $188,248 with the corresponding QALYs (LYs) increased by 0.90 (1.55), 1.09 (1.88), and 0.53 (0.79), leading to ICERs of $596,189/QALY ($347,995/LY), $530,061/QALY ($306,894/LY), and $1,011,310/QALY ($680,025/LY) in the overall, bevacizumab-naïve, and bevacizumab-pretreated patients, respectively. When MIRV is reduced by more than 75%, it may be a cost-effective treatment.

CONCLUSION

At the current price, MIRV for PROC with high-FRα expression is not the cost-effective strategy in the US. However, its treatment has higher health benefits in bevacizumab-naïve patients, which is likely to be an alternative.

Causal association between 637 human metabolites and ovarian cancer: a mendelian randomization study

BACKGROUND

Current evidence suggests a significant association between metabolites and ovarian cancer (OC); however, the causal relationship between the two remains unclear. This study employs Mendelian randomization (MR) to investigate the causal effects between different metabolites and OC.

METHODS

In this study, a total of 637 metabolites were selected as the exposure variables from the Genome-wide Association Study (GWAS) database ( http://gwas.mrcieu.ac.uk/datasets/ ). The OC related GWAS dataset (ieu-b-4963) was chosen as the outcome variable. R software and the TwoSampleMR package were utilized for the analysis in this study. MR analysis employed the inverse variance-weighted method (IVW), MR-Egger and weighted median (WM) for regression fitting, taking into consideration potential biases caused by linkage disequilibrium and weak instrument variables. Metabolites that did not pass the tests for heterogeneity and horizontal pleiotropy were considered to have no significant causal effect on the outcome. Steiger's upstream test was used to determine the causal direction between the exposure and outcome variables.

RESULTS

The results from IVW analysis revealed that a total of 31 human metabolites showed a significant causal effect on OC (P < 0.05). Among them, 9 metabolites exhibited consistent and stable causal effects, which were confirmed by Steiger's upstream test (P < 0.05). Among these 9 metabolites, Androsterone sulfate, Propionylcarnitine, 5alpha-androstan-3beta,17beta-diol disulfate, Total lipids in medium VLDL and Concentration of medium VLDL particles demonstrated a significant positive causal effect on OC, indicating that these metabolites promote the occurrence of OC. On the other hand, X-12,093, Octanoylcarnitine, N2,N2-dimethylguanosine, and Cis-4-decenoyl carnitine showed a significant negative causal association with OC, suggesting that these metabolites can inhibit the occurrence of OC.

CONCLUSIONS

The study revealed the complex effect of metabolites on OC through Mendelian randomization. As promising biomarkers, these metabolites are worthy of further clinical validation.

A signature based on anoikis-related genes for the evaluation of prognosis, immunoinfiltration, mutation, and therapeutic response in ovarian cancer

Background

Ovarian cancer (OC) is a highly lethal and aggressive gynecologic cancer, with an overall survival rate that has shown little improvement over the decades. Robust models are urgently needed to distinguish high-risk cases and predict reliable treatment options for OC. Although anoikis-related genes (ARGs) have been reported to contribute to tumor growth and metastasis, their prognostic value in OC remains unknown. The purpose of this study was to construct an ARG pair (ARGP)-based prognostic signature for patients with OC and elucidate the potential mechanism underlying the involvement of ARGs in OC progression.

Methods

The RNA-sequencing and clinical information data of OC patients were obtained from The Center Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. A novel algorithm based on pairwise comparison was utilized to select ARGPs, followed by the Least Absolute Shrinkage and Selection Operator Cox analysis to construct a prognostic signature. The predictive ability of the model was validated using an external dataset, a receiver operating characteristic curve, and stratification analysis. The immune microenvironment and the proportion of immune cells were analyzed in high- and low-risk OC cases using seven algorithms. Gene set enrichment analysis and weighted gene co-expression network analysis were performed to investigate the potential mechanisms of ARGs in OC occurrence and prognosis.

Results

The 19-ARGP signature was identified as an important prognostic predictor for 1-, 2-, and 3-year overall survival of patients with OC. Gene function enrichment analysis showed that the high-risk group was characterized by the infiltration of immunosuppressive cells and the enrichment of adherence-related signaling pathway, suggesting that ARGs were involved in OC progression by mediating immune escape and tumor metastasis.

Conclusion

We constructed a reliable ARGP prognostic signature of OC, and our findings suggested that ARGs exerted a vital interplay in OC immune microenvironment and therapeutic response. These insights provided valuable information regarding the molecular mechanisms underlying this disease and potential targeted therapies.

Development and verification of a 7-lncRNA prognostic model based on tumor immunity for patients with ovarian cancer

BACKGROUND

Both immune-reaction and lncRNAs play significant roles in the proliferation, invasion, and metastasis of ovarian cancer (OC). In this study, we aimed to construct an immune-related lncRNA risk model for patients with OC.

METHOD

Single sample GSEA (ssGSEA) algorithm was used to analyze the proportion of immune cells in The Cancer Genome Atlas (TCGA) and the hclust algorithm was used to conduct immune typing according to the proportion of immune cells for OC patients. The stromal and immune scores were computed utilizing the ESTIMATE algorithm. Weighted gene co-expression network analysis (WGCNA) and differentially expressed genes (DEGs) analyses were utilized to detect immune cluster-related lncRNAs. The least absolute shrinkage and selection operator (LASSO) regression was conducted for lncRNA selection. The selected lncRNAs were used to construct a prognosis-related risk model, which was then validated in Gene Expression Omnibus (GEO) database and in vitro validation.

RESULTS

We identify two subtypes based on the ssGSEA analysis, high immunity cluster (immunity_H) and low immunity cluster (immunity_L). The proportion of patients in immunity_H cluster was significantly higher than that in immunity_L cluster. The ESTIMATE related scores are relative high in immunity_H group. Through WGCNA and LASSO analyses, we identified 141 immune cluster-related lncRNAs and found that these genes were mainly enriched in autophagy. A signature consisting of 7 lncRNAs, including AL391832.3, LINC00892, LINC02207, LINC02416, PSMB8.AS1, AC078788.1 and AC104971.3, were selected as the basis for classifying patients into high- and low-risk groups. Survival analysis and area under the ROC curve (AUC) of the signature pointed out that this risk model had high accuracy in predicting the prognosis of patients with OC. We also conducted the drug sensitive prediction and found that rapamycin outperformed in patient with high risk score. In vitro experiments also confirmed our prediction.

CONCLUSIONS

We identified 7 immune-related prognostic lncRNAs that effectively predicted survival in OC patients. These findings may offer a valuable indicator for clinical stratification management and personalized therapeutic options for these patients.

Design, synthesis and anti-ovarian cancer activities of thieno[2,3-d]pyrimidine based chimeric BRD4 inhibitor/nitric oxide-donator

Bromodomain protein 4 (BRD4) is an attractive epigenetic target that regulating diverse cellular processes, and the discovery of dual-target inhibitors including BRD4 is an effective approach in cancer treatment to increase potency and reduce drug resistance. Based on the multifunctional drug development strategy, a series of new derivatives of nitrooxy (ONO₂) or furoxan (1,2,5-oxadiazole 2-oxide) with BRD4 inhibitor capable of inhibiting BRD4 and simultaneously releasing NO were designed and synthesized. When NO concentrations were measured with Griess reagent under physiological conditions, all compounds released NO at micromolar levels, reaching effective antitumor concentrations. Biological studies showed that the most potent BRD4/NO hybrid 11a exhibited good BRD4 inhibitory activity and selectivity. Further mechanistic studies revealed that 11a significantly decreased the expression of BRD4 and c-Myc, as well as induced cellular apoptosis and autophagic cell death both in vitro and in vivo. In summary, we optimized the chimeric BRD4-inhibitor/NO-donor based on our previous studies, and it should be a lead compound for targeted therapy of OC (ovarian cancer) in the future. This interesting strategy could expand the usage of BRDi in human malignancies and endogenous gastro-transmitters.

Identification of Novel Hypoxia Subtypes for Prognosis Based on Machine Learning Algorithms

Objective

A reduced level or tension or the deprivation of oxygen is termed hypoxia. It is common for tumours to outgrow their natural source of nutrients, which causes hypoxia in some tumour regions. Hypoxia affects ovarian cancer (OC) in several ways.

Methods

In this study, the expression patterns of prognostic hypoxia-related genes were curated, and consensus clustering analyses were performed to determine hypoxia subtypes in OC included in The Cancer Genome Atlas cohort. Two hypoxia-related subtypes were observed and considered for further investigation. The analyses of differentially expressed genes (DEGs), gene ontology, mutation, and immune cell infraction were performed to explore the underlying molecular mechanisms.

Results

In total, 377 patients with OC were classified into two subgroups based on the subtype of hypoxia. The clinical outcome was considerably poor for patients with hypoxia subtype 2. DEG and protein-protein interaction analyses revealed that the expression levels of CLIP2 and SH3PXD2A were low in OC tissues. Immune cell infarction analysis revealed that the subtypes were associated with the tumour microenvironment (TME).

Conclusion

Our findings established the existence of two distinctive, complex, and varied hypoxia subtypes in OC. Findings from the quantitative analysis of hypoxia subtypes in patients improved our understanding of the characteristics of the TME and may facilitate the development of more efficient treatment regimens.

RB1 Is an Immune-Related Prognostic Biomarker for Ovarian Cancer

Background

Ovarian cancer (OC) is one of the most lethal gynecologic malignancies and a leading cause of death in the world. Thus, this necessitates identification of prognostic biomarkers which will be helpful in its treatment.

Methods

The gene expression profiles from The Cancer Genome Atlas (TCGA) and GSE31245 were selected as the training cohort and validation cohort, respectively. The Kaplan–Meier (KM) survival analysis was used to analyze the difference in overall survival (OS) between high and low RB transcriptional corepressor 1 (RB1) expression groups. To confirm whether RB1 was an independent risk factor for OC, we constructed a multivariate Cox regression model. Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment analyses were conducted to identify the functions of differentially expressed genes (DEGs). The associations of RB1 with immune infiltration and immune checkpoints were studied by the Tumor Immune Estimation Resource (TIMER 2.0) and the Gene Expression Profiling Interactive Analysis (GEPIA). The immunohistochemistry (IHC) was performed to compare the expression level of RB1 in normal tissues and tumor samples, and to predict the prognosis of OC.

Results

The KM survival curve of the TCGA indicated that the OS in the high-risk group was lower than that in the low-risk group (HR = 1.61, 95% CI: 1.28-2.02, P = 3×10^-5), which was validated in GSE31245 (HR = 4.08, 95% CI: 1.21–13.74, P = 0.01) and IHC. Multivariate Cox regression analysis revealed that RB1 was an independent prognostic biomarker (HR = 1.66, 95% CI: 1.31-2.10, P = 2.02×10^-5). Enrichment analysis suggested that the DEGs were mainly involved in cell cycle, DNA replication, and mitochondrial transition. The infiltration levels of fibroblast, neutrophil, monocyte and macrophage were positively correlated with RB1. Furthermore, RB1 was associated with immune checkpoint molecules (CTLA4, LAG3, and CD274). The IHC staining revealed higher expression of RB1 in tumor tissues as compared to that in normal tissues (P = 0.019). Overexpression of RB1 was associated with poor prognosis of OC (P = 0.01).

Conclusion

These findings suggest that RB1 was a novel and immune-related prognostic biomarker for OC, which may be a promising target for OC treatment.

LncRNA HCG11 represses ovarian cancer cell growth via AKT signaling pathway

AIM

Ovarian cancer is a main contributor of cancer-relevant deaths among women worldwide due to high incidence and mortality. Mounting evidence has unveiled that lncRNAs play critical roles in malignancies, including ovarian cancer. Although the tumor suppressor function of HCG11 in prostate cancer and glioma has been proved, investigations on HCG11 role in ovarian cancer are still scarce.

METHODS

Gene or protein expression was quantified by RT-qPCR or western blot. HCG11 effects on ovarian cancer were assessed by functional assays. Bioinformatics analysis and mechanism experiments were implemented to identify the association among HCG11, miR-1270, and PTEN.

RESULTS

HCG11 was weakly expressed in ovarian cancer and functioned as a tumor suppressor in ovarian cancer by retarding cell proliferation, migration, and EMT. Besides, HCG11 could bind to miR-1270 and PTEN was a target gene of miR-1270. Mechanically, HCG11 competitively bound with miR-1270 to upregulate PTEN. From rescue experiments, HCG11 impeded AKT/mTOR pathway to retard ovarian cancer cell growth by miR-1270/PTEN.

CONCLUSIONS

HCG11 was a tumor suppressor in ovarian cancer cells and additionally, HCG11 regulated AKT/mTOR pathway to hinder ovarian cancer cell growth via modulating miR-1270/PTEN, indicating that HCG11 may represent a promising target for effective treatment of ovarian cancer patients.

Multiomic analysis identifies CPT1A as a potential therapeutic target in platinum-refractory, high-grade serous ovarian cancer

Resistance to platinum compounds is a major determinant of patient survival in high-grade serous ovarian cancer (HGSOC). To understand mechanisms of platinum resistance and identify potential therapeutic targets in resistant HGSOC, we generated a data resource composed of dynamic (±carboplatin) protein, post-translational modification, and RNA sequencing (RNA-seq) profiles from intra-patient cell line pairs derived from 3 HGSOC patients before and after acquiring platinum resistance. These profiles reveal extensive responses to carboplatin that differ between sensitive and resistant cells. Higher fatty acid oxidation (FAO) pathway expression is associated with platinum resistance, and both pharmacologic inhibition and CRISPR knockout of carnitine palmitoyltransferase 1A (CPT1A), which represents a rate limiting step of FAO, sensitize HGSOC cells to platinum. The results are further validated in patient-derived xenograft models, indicating that CPT1A is a candidate therapeutic target to overcome platinum resistance. All multiomic data can be queried via an intuitive gene-query user interface (https://sites.google.com/view/ptrc-cell-line).

Real-World Data on Treatment Management and Outcomes of Patients with Newly Diagnosed Advanced Epithelial Ovarian Cancer in Greece (The EpOCa Study)

New treatment modalities have been recently introduced in the management of ovarian cancer (OC). Herein, we sought to investigate their implementation in routine clinical practice and examine the real-world management of OC in Greece. EpOCa was a non-interventional, multicenter, retrospective study in patients with advanced epithelial OC. The primary outcome was to estimate the proportions of the different treatment regimens used per line of therapy, while progression-free survival (PFS) and overall survival (OS) were the key secondary endpoints. A total of 154 patients were enrolled in the study, among whom, 40% were tested for BRCA mutations and 30% were found to be positive. Nearly 90% of patients underwent debulking surgery at diagnosis, with few operations being also recorded upon relapse. Platinum-based chemotherapy (CT) was predominantly used in the first line with half of patients also receiving angiogenesis inhibitor (AI), while non-platinum-based CT was preferred in later lines. The median PFS was 18.2 and 8.8 months in the first- and second-line setting, respectively, whereas the median OS was approximately 50 months. Our study adds to the available, but limited, real world data on the management of ovarian cancer providing evidence regarding the applied treatment strategies and outcomes of patients in Greece.

Adavosertib with Chemotherapy in Patients with Primary Platinum-Resistant Ovarian, Fallopian Tube, or Peritoneal Cancer: An Open-Label, Four-Arm, Phase II Study

PURPOSE

This study assessed the efficacy, safety, and pharmacokinetics of adavosertib in combination with four chemotherapy agents commonly used in patients with primary platinum-resistant ovarian cancer.

PATIENTS AND METHODS

Women with histologically or cytologically confirmed epithelial ovarian, fallopian tube, or peritoneal cancer with measurable disease were enrolled between January 2015 and January 2018 in this open-label, four-arm, multicenter, phase II study. Patients received adavosertib (oral capsules, 2 days on/5 days off or 3 days on/4 days off) in six cohorts from 175 mg once daily to 225 mg twice daily combined with gemcitabine, paclitaxel, carboplatin, or pegylated liposomal doxorubicin. The primary outcome measurement was overall response rate.

RESULTS

Three percent of patients (3/94) had confirmed complete response and 29% (27/94) had confirmed partial response. The response rate was highest with carboplatin plus weekly adavosertib, at 66.7%, with 100% disease control rate, and median progression-free survival of 12.0 months. The longest median duration of response was in the paclitaxel cohort (12.0 months). The most common grade ≥3 adverse events across all cohorts were neutropenia [45/94 (47.9%) patients], anemia [31/94 (33.0%)], thrombocytopenia [30/94 (31.9%)], and diarrhea and vomiting [10/94 (10.6%) each].

CONCLUSIONS

Adavosertib showed preliminary efficacy when combined with chemotherapy. The most promising treatment combination was adavosertib 225 mg twice daily on days 1-3, 8-10, and 15-17 plus carboplatin every 21 days. However, hematologic toxicity was more frequent than would be expected for carboplatin monotherapy, and the combination requires further study to optimize the dose, schedule, and supportive medications.

Purified Vitexin Compound 1 Serves as a Promising Antineoplastic Agent in Ovarian Cancer

Ovarian cancer is a common gynecologic aggressive neoplasm. The mortality of ovarian cancer is top among gynecologic malignancies due to the insidious onset, atypical early symptoms, and chemoresistance. Therefore, it is urgent to seek another promising treatment for ovarian cancer. Purified vitexin compound 1 (VB1) is a kind of neolignan from the seed of traditional Chinese herb vitex negundo that possessed diverse pharmacological effects. VB1 can exhibit anti-neoplastic activities against various cancers. However, the role of VB1 in ovarian cancer treatment has not been elaborated, and the mechanism is unknown. The aim of this study was to investigate the therapeutic effects of VB1 in ovarian cancer cells both in vitro and in vivo, along with the molecular mechanism of action. In vitro, VB-1 can effectively suppress the proliferation, induce apoptosis, and block cell cycle at G2/M phase with a concentration dependent manner in ovarian cancer cells. Western blot assay showed that VB1 induce apoptosis via upregulating expression of cleaved-caspase3 and block cell cycle at G2/M phase through upregulating expression of P21. Meanwhile, VB1 can effectively inhibit tumor growth in xenograft mouse model. Our research indicated that VB1 can significantly exert its anti-neoplastic effects and may represent a new class of agents in ovarian cancer therapy.

PDK2 leads to cisplatin resistance through suppression of mitochondrial function in ovarian clear cell carcinoma

Ovarian clear cell carcinoma (CCC) exhibits an association with endometriosis, resistance to oxidative stress, and poor prognosis owing to its resistance to conventional platinum‐based chemotherapy. A greater understanding of the molecular characteristics and pathogenesis of ovarian cancer subtypes may facilitate the development of targeted therapeutic strategies, although the mechanism of drug resistance in ovarian CCC has yet to be determined. In this study, we assessed exome sequencing data to identify new therapeutic targets of mitochondrial function in ovarian CCC because of the central role of mitochondria in redox homeostasis. Copy number analyses revealed that chromosome 17q21‐24 (chr.17q21‐24) amplification was associated with recurrence in ovarian CCC. Cell viability assays identified an association between cisplatin resistance and chr.17q21‐24 amplification, and mitochondrion‐related genes were enriched in patients with chr.17q21‐24 amplification. Patients with high expression of pyruvate dehydrogenase kinase 2 (PDK2) had a worse prognosis than those with low PDK2 expression. Furthermore, inhibition of PDK2 synergistically enhanced cisplatin sensitivity by activating the electron transport chain and by increasing the production of mitochondrial reactive oxygen species. Mouse xenograft models showed that inhibition of PDK2 with cisplatin inhibited tumor growth. This evidence suggests that targeting mitochondrial metabolism and redox homeostasis is an attractive therapeutic strategy for improving drug sensitivity in ovarian CCC.

Personalized Medicine in Gynecologic Cancer: Fact or Fiction?

Personalized medicine in gynecologic oncology is an evolving field. In recent years, tumor profiling and large databases such as TCGA and NCI-Match have provided us with enormous amounts of molecular data. Several therapies that capitalize on novel genetic and immune discoveries including VEGF inhibitors, PARP inhibitors, and cancer vaccinations are discussed in this article. Additionally, we have seen direct to consumer marketing play an important role in cancer care and prevention as patients have increased ability to access genetic testing. This presents a unique challenge to gynecologic oncology providers as we learn to navigate the world of personalized medicine.

Inhibition of AXL enhances chemosensitivity of human ovarian cancer cells to cisplatin via decreasing glycolysis

Anexelekto (AXL), a member of the TYRO3-AXL-MER (TAM) family of receptor tyrosine kinases (RTK), is overexpressed in varieties of tumor tissues and promotes tumor development by regulating cell proliferation, migration and invasion. In this study, we investigated the role of AXL in regulating glycolysis in human ovarian cancer (OvCa) cells. We showed that the expression of AXL mRNA and protein was significantly higher in OvCa tissue than that in normal ovarian epithelial tissue. In human OvCa cell lines suppression of AXL significantly inhibited cell proliferation, and increased the sensitivity of OvCa cells to cisplatin, which also proved by nude mice tumor formation experiment. KEGG analysis showed that AXL was significantly enriched in the glycolysis pathways of cancer. Changes in AXL expression in OvCa cells affect tumor glycolysis. We demonstrated that the promotion effect of AXL on glycolysis was mediated by phosphorylating the M2 isoform of pyruvate kinase (PKM2) at Y105. AXL expression was significantly higher in cisplatin-resistant OvCa cells A2780/DDP compared with the parental A2780 cells. Inhibition of AXL decreased the level of glycolysis in A2780/DDP cells, and increased the cytotoxicity of cisplatin against A2780/DDP cells, suggesting that AXL-mediated glycolysis was associated with cisplatin resistance in OvCa. In conclusion, this study demonstrates for the first time that AXL is involved in the regulation of the Warburg effect. Our results not only highlight the clinical value of targeting AXL, but also provide theoretical basis for the combination of AXL inhibitor and cisplatin in the treatment of OvCa.

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.

Enhancing the sensitivity of ovarian cancer cells to olaparib via microRNA-20b-mediated cyclin D1 targeting

We previously reported that cyclin D1 silencing interferes with RAD51 accumulation and increases the sensitivity of BRCA1 wild-type ovarian cancer cells to olaparib. However, the mechanisms associated with cyclin D1 overexpression in ovarian cancer are not fully understood. TargetScan predicted the potential binding sites for microRNA-20b (miR-20b) and the 3'-untranslated region of cyclin D1 mRNA; thus, we used luciferase reporter assay to verify those binding sites. The Kaplan-Meier method and log-rank test were used to examine the relationship between miR-20b and progression-free survival of ovarian cancer patients in The Cancer Genome Atlas (n = 367) dataset. In vitro experiments were performed to evaluate the effects of miR-20b on cyclin D1 expression, cell cycle and response to olaparib. A peritoneal cavity metastasis model of ovarian cancer was established to determine the effect of miR-20b on the sensitivity of olaparib. Immunohistochemistry was performed to evaluate molecular mechanisms. In this work, we demonstrated that miR-20b down-regulates cyclin D1, increases the sensitivity of ovarian cancer cells to olaparib, reduces the expression of RAD51, and induces cell cycle arrest in G0/G1 phase. Ovarian cancer patients with higher expression of miR-20b had significantly longer progression-free survival. These results indicate that miR-20b may be a potential clinical indicator for the sensitivity of ovarian cancer to olaparib and the survival of ovarian cancer patients. Our findings suggest that miR-20b may have therapeutic value in combination with olaparib treatment for ovarian cancer.

Development and Validation of an Immune-Related Gene-Pair Model of High-Grade Serous Ovarian Cancer After Platinum-Based Chemotherapy

Background

High-grade serous ovarian cancer (HGSOC) is a common cause of death from gynecological cancer, with an overall survival rate that has not significantly improved in decades. Reliable bio-markers are needed to identify high-risk HGSOC to assist in the selection and development of treatment options.

Method

The study included ten HGSOC cohorts, which were merged into four separate cohorts including a total of 1,526 samples. We used the relative expression of immune genes to construct the gene-pair matrix, and the least absolute shrinkage and selection operator regression was performed to build the prognosis model using the training set. The prognosis of the model was verified in the training set (363 cases) and three validation sets (of 251, 354, and 558 cases). Finally, the differences in immune cell infiltration and gene enrichment pathways between high and low score groups were identified.

Results

A prognosis model of HGSOC overall survival rate was constructed in the training set, and included data for 35 immune gene-related gene pairs and the regression coefficients. The risk stratification of HGSOC patients was successfully performed using the training set, with a p-value of Kaplan-Meier of < 0.001. A score from this model is an independent prognostic factor of HGSOC, and prognosis was evaluated in different clinical subgroups. This model was also successful for the other three validation sets, and the results of Kaplan-Meier analysis were statistically significant (p < 0.05). The model can also predict patient progression-free survival with HGSOC to reflect tumor growth status. There was a lower infiltration level of M1 macrophages in the high-risk group compared to that in the low-risk group (p < 0.001). Finally, the immune-related pathways were enriched in the low-risk group.

Conclusion

The prognostic model based on immune-related gene pairs developed is a potential prognostic marker for high-grade serous ovarian cancer treated with platinum. The model has robust prognostic ability and wide applicability. More prospective studies will be needed to assess the practical application of this model for precision therapy.

Silencing of lncRNA DLEU1 inhibits tumorigenesis of ovarian cancer via regulating miR-429/TFAP2A axis

Long non-coding RNAs (lncRNAs) are known as crucial regulators in the development of OC. In the current study, we aim to explore the function and molecular mechanism of lncRNA DLEU1 in OC. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to determine the expression of DLEU1, miR-429, and TFAP2A in OC cells and tissues. The relationship among DLEU1, miR-429, and TFAP2A was tested by dual-luciferase reporter (DLR) assay. Besides, the proliferative, migratory and invasive abilities of OC cells were analyzed by MTT, wound healing, and transwell assays, respectively. Western blot was performed to determine the protein expression of TFAP2A. The expression of lncRNA DLEU1 and TFAP2A were upregulated, and miR-429 was downregulated in OC tissues. Silencing of DLEU1 inhibited the proliferation, migration, and invasion of OC cells. Bioinformation and DLR assay showed that DLEU1 acted as the sponge for miR-429. Moreover, miR-429 could directly target TFAP2A and inhibit the proliferation, migration, and invasion of OC cells. Moreover, we observed a negative correlation between miR-429 and DLEU1, and between miR-429 and TFAP2A in OC tissues. The transfection of miR-429 inhibitor or pcDNA-TFAP2A reversed the inhibitory effects of si-DLEU1 on the proliferation, migration, and invasion of OC cells. Silencing of DLEU1 inhibited the proliferation, migration, and invasion of OC cells by regulating miR-429/TFAP2A axis, indicating a potential therapeutic target for OC.

Deregulation of Lipid Metabolism: The Critical Factors in Ovarian Cancer

Ovarian cancer is one of the most malignant gynecological cancers around the world. In spite of multiple treatment options, the five-year survival rate is still very low. Several metabolism alterations are described as a hallmark in cancers, but alterations of lipid metabolism in ovarian cancer have been paid less attention. To explore new markers/targets for accurate diagnosis, prognosis, and therapeutic treatments based on metabolic enzyme inhibitors, here, we reviewed available literature and summarized several key metabolic enzymes in lipid metabolism of ovarian cancer. In this review, the rate limiting enzymes associated with fatty acid synthesis (FASN, ACC, ACLY, SCD), the lipid degradation related enzymes (MAGL, CPT, 5-LO, COX2), and the receptors related to lipid uptake (FABP4, CD36, LDLR), which promote the development of ovarian cancer, were analyzed and evaluated. We also focused on the review of application of current metabolic enzyme inhibitors for the treatment of ovarian cancer through which the potential therapeutic agents may be developed for ovarian cancer therapy.

A novel signature of two long non-coding RNAs in BRCA mutant ovarian cancer to predict prognosis and efficiency of chemotherapy

BACKGROUND

In this study we aimed to identify a prognostic signature in BRCA1/2 mutations to predict disease progression and the efficiency of chemotherapy ovarian cancer (OV), the second most common cause of death from gynecologic cancer in women worldwide.

METHODS

Univariate Cox proportional-hazards and multivariate Cox regression analyses were used to identifying prognostic factors from data obtained from The Cancer Genome Atlas (TCGA) database. The area under the curve of the receiver operating characteristic curve was assessed, and the sensitivity and specificity of the prediction model were determined.

RESULTS

A signature consisting of two long noncoding RNAs(lncRNAs), Z98885.2 and AC011601.1, was selected as the basis for classifying patients into high and low-risk groups (median survival: 7.2 years vs. 2.3 years). The three-year overall survival (OS) rates for the high- and low-risk group were approximately 38 and 100%, respectively. Chemotherapy treatment survival rates indicated that the high-risk group had significantly lower OS rates with adjuvant chemotherapy than the low-risk group. The one-, three-, and five-year OS were 100, 40, and 15% respectively in the high-risk group. The survival rate of the high-risk group declined rapidly after 2 years of OV chemotherapy treatment. Multivariate Cox regression associated with other traditional clinical factors showed that the 2-lncRNA model could be used as an independent OV prognostic factor. Analyses of data from the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) indicated that these signatures are pivotal to cancer development.

CONCLUSION

In conclusion, Z98885.2 and AC011601.1 comprise a novel prognostic signature for OV patients with BRCA1/2 mutations, and can be used to predict prognosis and the efficiency of chemotherapy.

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.

Baicalin Attenuates YAP Activity to Suppress Ovarian Cancer Stemness

Purpose

This study aims to reveal the mechanism underlying baicalin-suppressing ovarian cancer stemness.

Methods

OVCAR-3 and the primary ovarian cancer cells were used for cell model. The ovarian cancer stem cells were isolated by suspension culture. Cell viability and clonogenicity were examined by CCK-8 assay and colony formation assay. The self-renewal of the cells was evaluated by the determination of sphere-forming capacity and the frequency of in vitro sphere-forming and in vivo tumor-initiating cells. The mRNA and protein levels were relatively quantified by qRT-PCR and Western blot. The transcription regulation of target genes was tested by luciferase reporter assay and a modified nuclear rn-on qRT-PCR assay.

Results

Treatment with a non-toxic dose of baicalin significantly inhibited the spherogenicity of ovarian cancer cells. Moreover, a non-toxic dose of baicalin treatment suppressed the frequency of sphere-forming and tumor-initiating ovarian cancer cells. Furthermore, the expression of ovarian cancer stem cell markers (CD133 and ALDH1A1) was inhibited by a non-toxic dose of baicalin treatment. Baicalin inhibits YAP activity and suppresses RASSF6, a positive regulator of YAP, at the transcriptional level. Overexpression of both YAP and RASSF6 abolished the inhibitory effect of baicalin on the proliferation and stemness of ovarian cancer cells.

Conclusion

The results in this study demonstrated that baicalin suppresses the stemness of ovarian cancer cells by attenuating YAP activity via inhibiting RASSF6 at the transcriptional level. This finding revealed baicalin as a novel YAP inhibitor that could serve as an anti-cancer drug for eradicating ovarian cancer stem cells.

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.

CircRNA FGFR3 induces epithelial-mesenchymal transition of ovarian cancer by regulating miR-29a-3p/E2F1 axis

Circular RNAs (circRNAs) are a class of non-coding RNAs that regulate gene expression after transcription. However, the specific function of circRNAs in ovarian cancer remains undetermined. Previous studies have demonstrated abnormal expression of circFGFR3 in several cancers. The present study was designed to reveal the roles of circFGFR3 in ovarian cancer (OC). CircFGFR3 expression in OC tissues and cells was detected by RT-qPCR. The effects of CircFGFR3 on OC cells were evaluated by transwell assay and CCK-8 assay. Finally, the underlying mechanism was further revealed by luciferase reporter assay and western blotting. Our results showed that circFGFR3 expression was higher in OC cells and tissues than in normal ovarian cells and adjacent normal tissues; in addition, in OC patients, a high level of CircFGFR3 was related to lower survival rates and higher recurrence rates than a low level of circFGFR3. CircFGFR3 overexpression promotes OC progression by inducing epithelial-mesenchymal transition (EMT) in vitro. Mechanistically, circFGFR3 upregulates E2F1 expression by sponging miR-29a-3p, and the overexpression of E2F1 or the suppression of miR-29a-3p induces OC cell EMT. Therefore, circFGFR3 serves as a promoter of OC by inducing OC cell EMT via the miR-29a-3p/E2F1 axis and circFGFR3 may be a prognostic biomarker for OC patients.

MicroRNA-1271-5p inhibits the tumorigenesis of ovarian cancer through targeting E2F5 and negatively regulates the mTOR signaling pathway

BACKGROUND

MicroRNA-1271-5p (miR-1271-5p) has been reported to participate in the progression of many human cancers. However, the role of miR-1271-5p still remains unclear in ovarian cancer (OC). Therefore, we explored the effect of miR-1271-5p on the development of OC in present study.

METHODS

We measured the miR-1271-5p expression via the qRT-PCR assay. Then the function of miR-1271-5p was analyzed through MTT and Transwell assays. The relationship among miR-1271-5p and E2F5 was verified by dual luciferase assay. The protein expression levels were examined through western blot.

RESULTS

MiR-1271-5p was downregulated in OC tissues which predicted poor prognosis of OC patients. Moreover, E2F5 was a direct target of miR-1271-5p in OC. And miR-1271-5p suppressed cell proliferation, migration and invasion in OC through targeting E2F5. Furthermore, E2F5 was upregulated in OC tissues which predicted poor prognosis of OC patients. Besides that, miR-1271-5p suppressed EMT and mTOR pathway in OC.

CONCLUSIONS

MiR-1271-5p inhibited the tumorigenesis of OC through targeting E2F5 and negatively regulated the mTOR signaling pathway.

LncRNA EMX2OS Induces Proliferation, Invasion and Sphere Formation of Ovarian Cancer Cells via Regulating the miR-654-3p/AKT3/PD-L1 Axis

PURPOSE

Long noncoding RNA (lncRNA) deregulation is frequent in human ovarian cancers (OCs), but the role of specific miRNAs involved in this disease remains elusive. LncRNA EMX2OS was previously reported to act as an oncogene in human cancers. However, their accurate expression, function and underlying mechanisms in OC are largely unclear.

MATERIALS AND METHODS

The levels of EMX2OS in OC tissues and cell lines were determined by quantitative real-time PCR, and the function of EMX2OS was then analyzed both in vitro and in vivo. Luciferase assays and immunoprecipitation assays were performed to analyze the association between EMX2OS and miR-654 expression in OC cells.

RESULTS

EMX2OS is overexpressed in human ovarian cancer tissues. Knockdown of EMX2OS reduced, while overexpression of EMX2OS enhanced the proliferation, invasion and sphere formation of OC cells. In addition, EMX2OS enhanced tumor growth in an in vivo xenograft model of human OC. We discovered that EMX2OS directly binds to miR-654 and suppresses its expression, thus leading to the upregulation of AKT3, which served as a direct target of miR-654. Moreover, miR-654 inhibited cell proliferation, invasion and sphere formation, and restoration of AKT3 reversed the effects of EMX2OS silencing or miR-654 overexpression. Furthermore, PD-L1 was identified as the key oncogenic component acting downstream of AKT3 in OC cells. Ectopic expression of PD-L1 reversed the anti-cancer functions by EMX2OS knockdown, AKT3 silencing or miR-654 upregulation in OC cells.

CONCLUSION

These results demonstrated that the EMX2OS/miR-654/AKT3/PD-L1 axis confers aggressiveness in ovarian cancer and may represent a therapeutic target for OC metastasis.

Ovarian cancer stem cells: ready for prime time?

INTRODUCTION

The role of cancer stem cells (CSC) remains controversial and increasingly subject of investigation as a potential oncogenetic platform with promising therapeutic implications. Understanding the role of CSCs in a highly heterogeneous disease like epithelial ovarian cancer (EOC) may potentially lead to the better understanding of the oncogenetic and metastatic pathways of the disease, but also to develop novel strategies against its progression and platinum resistance.

METHODS

We have performed a review of all relevant literature that addresses the oncogenetic potential of stem cells in EOC, their mechanisms, and the associated therapeutic targets.

RESULTS

Cancer stem cells (CSCs) have been reported to be implicated not only in the development and pathways of intratumoral heterogeneity (ITH), but also potentially modulating the tumor microenvironment, leading to the selection of sub-clones resistant to chemotherapy. Furthermore, it appears that the enhanced DNA repair abilities of CSCs are connected with their endurance and resistance maintaining their genomic integrity during novel targeted treatments such as PARP inhibitors, allowing them to survive and causing disease relapse functioning as a tumor seeds.

CONCLUSIONS

It appears that CSCs play a major role in the underlying mechanisms of oncogenesis and development of relapse in EOC. Part of promising future plans would be to not only use them as therapeutic targets, but also extent their value on a preventative level through engineering mechanisms and prevention of EOC in its origin.

CNDP2 Acts as an Activator for Human Ovarian Cancer Growth and Metastasis via the PI3K/AKT Pathway

Introduction:

The mechanism of tumorigenesis and metastasis of ovarian cancer has not yet been elucidated. This study aimed to investigate the role and molecular mechanism of cytosolic nonspecific dipeptidase 2 in tumorigenesis and metastasis.

Methods:

Cytosolic nonspecific dipeptidase 2 expression in human ovarian cancer tissues and cell lines was assessed with methyl thiazolyl tetrazolium (MTT), clone formation, and transwell assays performed to evaluate the ability of ovarian cancer cells to proliferate and migrate. Nude mice tumor formation experiments were also performed by subcutaneously injecting cells with stable cytosolic nonspecific dipeptidase 2 knockdown and control SKOV3 cells into BALB/c female nude mice to detect changes in PI3K/AKT pathway-related proteins by Western blotting.

Results:

Cytosolic nonspecific dipeptidase 2 was highly expressed in human ovarian cancer tissues, with its expression associated with pathological data, including ovarian cancer metastasis. A cytosolic nonspecific dipeptidase 2 stable knockdown or ectopic expression ovarian cancer cell model was established and demonstrated that cytosolic nonspecific dipeptidase 2 could promote the proliferation of ovarian cancer cells. Transwell cell migration and invasion assays confirmed that cytosolic nonspecific dipeptidase 2 enhanced cell metastasis in ovarian cancer. Furthermore, in vivo xenograft experiments demonstrated that cytosolic nonspecific dipeptidase 2 can promote the development and progression of ovarian cancer, increasing the expression of phosphorylated PI3K and AKT.

Conclusions:

Cytosolic nonspecific dipeptidase 2 promotes the occurrence and development of ovarian cancer through the PI3K/AKT signaling pathway.

CDK7 is a reliable prognostic factor and novel therapeutic target in epithelial ovarian cancer

OBJECTIVE

Cyclin-dependent kinase 7 (CDK7) engages tumor growth by acting as a direct link between the regulation of transcription and the cell cycle. Here, we investigated the clinical significance of CDK7 expression and its potential as a therapeutic target in epithelial ovarian cancer (EOC).

METHODS

CDK7 expression was examined in 436 ovarian tissues including normal to metastatic ovarian tumors using immunohistochemistry, and its clinical implications were analyzed. Furthermore, we performed in vitro and in vivo experiments using CDK7 siRNA or a covalent CDK7 inhibitor (THZ1) to elucidate the effect of CDK7 inhibition on tumorigenesis in EOC cells.

RESULTS

The patient incidence of high CDK7 expression (CDK7^High) gradually increased from normal ovarian epithelium to EOC (P < 0.001). Moreover, CDK7^High was associated with an advanced stage and high-grade histology (P = 0.035 and P = 0.011, respectively) in EOC patients and had an independent prognostic significance in EOC recurrence (P = 0.034). CDK7 inhibition with siRNA or THZ1 decreased cell proliferation and migration, and increased apoptosis in EOC cells, and this anti-cancer mechanism is caused by G0/G1 cell cycle arrest. In in vivo therapeutic experiments using cell-line xenograft and PDX models, CDK7 inhibition significantly decreased the tumor weight, which was mediated by cell proliferation and apoptosis.

CONCLUSION

Mechanistic interrogation of CDK7 revealed that it is significantly associated with an aggressive phenotype of EOC, and it has independent prognostic power for EOC recurrence. Furthermore, CDK7 may be a potential therapeutic target for patients with EOC, whether platinum sensitive or resistant.

Apoptotic SKOV3 cells stimulate M0 macrophages to differentiate into M2 macrophages and promote the proliferation and migration of ovarian cancer cells by activating the ERK signaling pathway

Ovarian cancer has a high rate of recurrence, with M2 macrophages having been found to be involved in its progression and metastasis. To examine the relationship between macrophages and ovarian cancer in the present study, M0 macrophages were stimulated with apoptotic SKOV3 cells and it was found that these macrophages promoted tumor proliferation and migration. Subsequently, the mRNAs and proteins expressed at high levels in these M2 macrophages were examined by RNA-Seq and quantitative proteomics, respectively, which revealed that M0 macrophages stimulated by apoptotic SKOV3 cells also expressed M2 markers, including CD206, interleukin-10, C-C motif chemokine ligand 22, aminopeptidase-N, disabled homolog 2, matrix metalloproteinase 1 and 5′-nucleotidase. The abundance of phosphorylated Erk1/2 in these macrophages was increased. The results indicate that apoptotic SKOV3 cells stimulate M0 macrophages to differentiate into M2 macrophages by activating the ERK pathway. These results suggest possible treatments for patients with ovarian cancer who undergo chemotherapy; inhibiting M2 macrophage differentiation during chemotherapy may reduce the rate of tumor recurrence.

A Novel Scoring System for Pivotal Autophagy-Related Genes Predicts Outcomes after Chemotherapy in Advanced Ovarian Cancer Patients

BACKGROUND

In the clinical practice of ovarian cancer, the application of autophagy, an important regulator of carcinogenesis and chemoresistance, is still limited. This study aimed to establish a scoring system based on expression profiles of pivotal autophagy-related (ATG) genes in patients with stage III/IV ovarian cancer who received chemotherapy.

METHODS

Data of ovarian serous cystadenocarcinoma in The Cancer Genome Atlas (TCGA-OV) were used as training dataset. Two validation datasets comprised patients in a Chinese local database and a dataset from the Gene Expression Omnibus (GEO). ATG genes significantly (P < 0.1) associated with overall survival (OS) were selected and aggregated into an ATG scoring scale, of which the abilities to predict OS and recurrence-free survival (RFS) were examined.

RESULTS

Forty-three ATG genes were selected to develop the ATG score. In TCGA-OV, patients with lower ATG scores had better OS [HR = 0.41; 95% confidence interval (CI), 0.26-0.65; P < 0.001] and RFS [HR = 0.47; 95% CI, 0.27-0.82; P = 0.007]. After complete or partial remission to primary therapy, the rate of recurrence was 47.2% in the low-score group and 68.3% in the high-score group (odds ratio = 0.42; 95% CI, 0.18-0.92; P = 0.03). Such findings were verified in the two validation datasets.

CONCLUSIONS

We established a novel scoring system based on pivotal ATG genes, which accurately predicts the outcomes of patients with advanced ovarian cancer after chemotherapy.

IMPACT

The present ATG scoring system may provide a novel perspective and a promising tool for the development of personalized therapy in the future.

Jumonji domain-containing 6 (JMJD6) identified as a potential therapeutic target in ovarian cancer

Jumonji domain-containing 6 (JMJD6) is a candidate gene associated with tumorigenesis, and JMJD6 overexpression predicts poor differentiation and unfavorable survival in some cancers. However, there are no studies reporting the expression of JMJD6 in ovarian cancer, and no JMJD6 inhibitors have been developed and applied to targeted cancer therapy research. In the present study, we found that the high expression of JMJD6 in ovarian cancer was correlated with poor prognosis in ovarian cancer. A potential inhibitor (SKLB325) was designed based on the crystal structure of the jmjC domain of JMJD6. This molecule significantly suppressed proliferation and induced apoptosis in a dose-dependent manner in SKOV3 cell lines as detected by CCK-8 cell proliferation assays and flow cytometry. A Matrigel endothelial tube formation assay showed that SKLB325 inhibited capillary tube organization and migration in HUVECs in vitro. We also observed that JMJD6 colocalized with p53 protein in the nucleus, with mRNA and protein expression of p53 as well as its downstream effectors significantly increasing both in vitro and in intraperitoneal tumor tissues treated with SKLB325. In addition, SKLB325 significantly reduced the intraperitoneal tumor weight and markedly prolonged the survival of tumor-bearing mice. Taken together, our findings suggest that JMJD6 may be a marker of poor prognosis in ovarian cancer and that SKLB325 may be a potential candidate drug for the treatment of ovarian cancer.

Effects of dynein light chain Tctex-type 3 on the biological behavior of ovarian cancer

OBJECTIVE

To investigate dynein light chain Tctex-type 3 (DYNLT3) protein expression in ovarian epithelial lesions and explore the effects and related mechanisms of DYNLT3 in terms of the biological behavior of ovarian cancer.

MATERIALS AND METHODS

Initially, expression of the DYNLT3 protein in ovarian epithelial lesions was detected by immunohistochemical staining, and the prognostic value of DYNLT3 mRNA expression in ovarian cancer patients was assessed using the Kaplan-Meier plotter database. Then, the mRNA and protein expression of DYNLT3 in IOSE80 normal ovarian epithelial cells and SKOV3 ovarian cancer cells was evaluated by quantitative real-time polymerase chain reaction and Western blotting respectively, and the proliferation, apoptosis, migration and invasion of SKOV3 cells after DYNLT3 over-expression and under-expression were investigated by CCK-8 assays and immunofluorescence staining, flow cytometry, wound healing assays and Transwell invasion assays, respectively. Furthermore, the expression of the proliferation-related proteins PCNA and Ki-67 and the invasion- and migration-related proteins Ezrin, Fascin, MMP2 and MMP9 in cells was examined by Western blotting.

RESULTS

The protein expression of DYNLT3 gradually increased during the progression of ovarian epithelial lesions, and was related to the development of ovarian cancer. High expression of DYNLT3 mRNA was related to poor overall survival and progression free survival, especially in serous ovarian cancer patients. In addition, overexpression of DYNLT3 promoted SKOV3 cell proliferation, invasion and migration. The corresponding results were also verified by a DYNLT3 knockdown assay. Moreover, DYNLT3 increased cell proliferation, which was related to Ki-67 expression. Besides, DYNLT3 enhanced cell invasion and migration through regulating Ezrin, but not Fascin, MMP2 or MMP9.

CONCLUSION

DYNLT3 exerts pro-tumoral effects on ovarian cancer through promoting cell proliferation, migration and invasion, possibly via regulating the protein expression of Ki-67 and Ezrin. DYNLT3 may be a potential prognostic predictor in ovarian cancer.

Overexpression of RASAL1 Indicates Poor Prognosis and Promotes Invasion of Ovarian Cancer

RAS protein activator like-1 (RASAL1) exists in numerous human tissues and has been commonly demonstrated to act as a tumor suppressor in several cancers. This study aimed to identify the functional characteristics of RASAL1 in ovarian adenocarcinoma and a potential mechanism of action. We analyzed RASAL1 gene expression in ovarian adenocarcinoma samples and normal samples gained from the GEO and Oncomine databases respectively. Then the relationship between RASAL1 expression and overall survival (OS) was assessed using the Kaplan-Meier method. Furthermore, the biological effect of RASAL1 in ovarian adenocarcinoma cell lines was assessed by Quantitative real time-PCR (qRT-PCR), Cell Counting Kit-8 (CCK-8), western blot, wound healing and transwell assay. The statistical analysis showed patients with higher RASAL1 expression correlated with worse OS. The in vitro assays suggested knockdown of RASAL1 could inhibit cell proliferation, cell invasion and migration of ovarian adenocarcinoma. Moreover, the key proteins in the mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK/ERK) signaling pathway were also decreased in ovarian adenocarcinoma cells with RASAL1 silencing. These findings provide promising evidence that RASAL1 may be not only a powerful biomarker but also an effective therapeutic target of ovarian adenocarcinoma.

Inhibition of JAK2/STAT3 and activation of caspase‑9/3 are involved in KYS05090S‑induced apoptosis in ovarian cancer cells

To overcome the poor prognosis of patients with ovarian cancer, attempting to target ovarian cancer with effective antitumor compounds has been conducted for numerous years. Although the 3,4‑dihydroquinazoline derivative KYS05090S was known to exert antitumor effects in A549 and ovarian cancer cells by inhibition of T‑type Ca2+ channels, the complete underlying antitumor mechanism of this compound remains unclear. Thus, in the present study, the potential apoptotic mechanism of KYS05090S was elucidated in SKOV3 and OVCAR3 ovarian cancer cells. KYS05090S exerted significant cytotoxicity in SKOV3 and OVCAR3 ovarian cancer cells, and also increased the number of apoptotic bodies, and the number of terminal deoxynucleotidyl transferase dUTP nick end labeling positive cells and the sub‑G1 population as a feature of apoptosis. Consistently, KYS05090S induced cleavage of poly(ADP‑ribose) polymerase and caspase‑9/3 in ovarian cancer cells. Notably, KYS05090S attenuated the expression of anti‑apoptotic proteins, including cyclin D1 and B‑cell lymphoma‑2 (Bcl‑2), and reduced the phosphorylation of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) in ovarian cancer cells. Additionally, KYS05090S blocked the nuclear translocation of STAT3 and suppressed the signaling of JAK2/STAT3 in interleukin‑6‑treated SKOV3 cells, as a STAT3 activator. Overall, these observations indicated that inhibition of JAK2/STAT3 signaling and activation of caspase‑9/3 are critically involved in the effects of KYS05090S on apoptosis in ovarian cancer types, and the compound may be beneficial as a potent antitumor agent.

Prognostic Significance of CD109 Expression in Patients with Ovarian Epithelial Cancer

Background

Ovarian epithelial cancer (OEC) is the second-most common gynecologic malignancy. CD109 expression is elevated in human tumor cell lines and carcinomas. A previous study showed that CD109 expression is elevated in human tumor cell lines and CD109 plays a role in cancer progression. Therefore, this study aimed to determine whether CD109 is expressed in OEC and can be useful in predicting the prognosis.

Methods

Immunohistochemical staining for CD109 and reverse transcription-quantitative polymerase chain reaction was performed. Then we compared CD109 expression and chemoresistance, overall survival, and recurrence-free survival of OEC patients. Chemoresistance was evaluated by dividing into good-response group and poor-response group by the time to recurrence after chemotherapy.

Results

CD109 expression was associated with overall survival (p = .020), but not recurrence-free survival (p = .290). CD109 expression was not an independent risk factor for overall survival due to its reliability (hazard ratio, 1.58; p = .160; 95% confidence interval, 0.82 to 3.05), although we found that CD109 positivity was related to chemoresistance. The poor-response group showed higher rates of CD109 expression than the good-response group (93.8% vs 66.7%, p = .047). Also, the CD109 mRNA expression level was 2.88 times higher in the poor-response group as compared to the good-response group (p = .001).

Conclusions

Examining the CD109 expression in patients with OEC may be helpful in predicting survival and chemotherapeutic effect.

Poly (ADP-ribose) polymerase inhibitors combined with other small-molecular compounds for the treatment of ovarian cancer

Ovarian cancer is a heterogeneous disease with complex molecular and genetic hallmarks. Benefitting from profound understanding of molecular mechanisms in ovarian cancer pathogenesis, novel targeted drugs have been actively explored in preclinical studies and clinical trials. Considered as one of the most potent and effective targeted therapies for the treatment of ovarian cancer, poly (ADP-ribose) polymerase (PARP) inhibitors (PARPis) take advantages of synthetic lethality mechanisms to prevent DNA damage repair in cancer cells and cause their death, especially in cancers with BRCA mutations. Mounting evidence has indicated that the combination of PARPis with cytotoxic drugs or other targeted drugs has shown favorable synergistic effects. Excitingly, the antitumor activity of combination therapy of PARPis has been actively tested in multiple clinical trials and in-vitro or in-vivo experiments. In this review, we will briefly discuss the molecular mechanisms of PARPis combined with other therapeutic small-molecular compounds for the treatment of ovarian cancer.

ITLNI identified by comprehensive bioinformatic analysis as a hub candidate biological target in human epithelial ovarian cancer

Background

Epithelial ovarian cancer (EOC) is a female malignant tumor. Bioinformatics has been widely utilized to analyze genes related to cancer progression. Targeted therapy for specific biological factors has become more valuable.

Materials and methods

Gene expression profiles of GSE18520 and GSE27651 were downloaded from Gene Expression Omnibus. We used the “limma” package to screen differentially expressed genes (DEGs) between EOC and normal ovarian tissue samples and then used Clusterprofiler to do functional and pathway enrichment analyses. We utilized Search Tool for the Retrieval of Interacting Genes Database to assess protein–protein interaction (PPI) information and the plug-in Molecular Complex Detection to screen hub modules of PPI network in Cytoscape, and then performed functional analysis on the genes in the hub module. Next, we utilized the Weighted Gene Expression Network Analysis package to establish a co-expression network. Validation of the key genes in databases and Gene Expression Profiling Interactive Analysis (GEPIA) were completed. Finally, we used quantitative real-time PCR to validate hub gene expression in clinical tissue samples.

Results

We analyzed the DEGs (96 samples of EOC tissue and 16 samples of normal ovarian tissue) for functional analysis, which showed that upregulated DEGs were strikingly enriched in phosphate ion binding and the downregulated DEGs were significantly enriched in glycosaminoglycan binding. In the PPI network, CDK1 was screened as the most relevant protein. In the co-expression network, one EOC-related module was identified. For survival analysis, database and clinical sample validation of genes in the turquoise module, we found that ITLN1 was positively correlated with EOC prognosis and had lower level in EOC than in normal tissues, which was consistent with the results predicted in GEPIA.

Conclusion

In this study, we exhibited the key genes and pathways involved in EOC and speculated that ITLN1 was a tumor suppressor which could be used as a potential biomarker for treating EOC, Gene Expression Omnibus, prognosis.

Personalized Medicine in Gynecologic Cancer: Fact or Fiction?

Personalized medicine in gynecologic oncology is an evolving field. In recent years, tumor profiling and large databases such as TCGA and NCI-Match have provided us with enormous amounts of molecular data. Several therapies that capitalize on novel genetic and immune discoveries including VEGF inhibitors, PARP inhibitors, and cancer vaccinations are discussed in this article. Additionally, we have seen direct to consumer marketing play an important role in cancer care and prevention as patients have increased ability to access genetic testing. This presents a unique challenge to gynecologic oncology providers as we learn to navigate the world of personalized medicine.

HOXD-AS1 promotes the epithelial to mesenchymal transition of ovarian cancer cells by regulating miR-186-5p and PIK3R3

Background

Epithelial ovarian cancer (EOC) is one of the most malignant gynecological tumors worldwide. Deregulation of long non-coding RNAs (lncRNAs) has been implicated in various oncogenic processes in multiple cancers. In this study, we aim to identify and characterize clinically relevant lncRNA deregulation in EOC.

Methods

LncRNAs, mRNAs and miRNAs were profiled using expression microarrays and validated using reverse transcription quantitative PCR in EOC cells and tissues. siRNAs targeting either HOXD-AS1 or PIK3R3 together with miR-186-5p inhibitors were used to modulate endogenous target expression in EOC cell lines in vitro. In vitro wound healing assay, trans-well assay, Western-blot assay,and Dual-luciferase reporter assay were used to explore the biological roles and molecular function underlying HOXD-AS1 in the EOC cells. Progression-free survival (PFS) and overall survival (OS) were statistically analyzed by Kaplan-Meier method test.

Results

HOXD-AS1 was found to be significantly over-expressed in EOC tumors. High HOXD-AS1 expression significantly correlated with poorer PFS and OS of EOC patients. Multivariate Cox proportional hazards modeling indicated that HOXD-AS1 was an independent risk predictor of EOC patients (HR = 1.92, p = 0.004). SiRNA inhibition of HOXD-AS1 reduced cell migration, invasion, and epithelial-mesenchymal transition (EMT) in EOC cells in vitro by preventing HOXD-AS1 directly binding to miR-186-5p, and resulting in down-regulating of PIK3R3. The novel HOXD-AS1/miR-186-5p/PIK3R3 pathway was clinically relevant as we observed a significantly inverse correlation between HOXD-AS1/miR-186-5p and between miR-186-5p/PIK3R3 in an independent cohort of 200 EOC tissues.

Conclusions

HOXD-AS1/miR-186-5p/PIK3R3 is a novel pathway to promote cell migration, invasion, and EMT in EOC.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1103-5) contains supplementary material, which is available to authorized users.

The Case for Proteomics and Phospho-Proteomics in Personalized Cancer Medicine

The concept of personalized medicine is predominantly been pursued through genomic and transcriptomic technologies, leading to the identification of multiple mutations in a large variety of cancers. However, it has proven challenging to distinguish driver and passenger mutations and to deal with tumor heterogeneity and resistant clonal populations. More generally, these heterogeneous mutation patterns do not in themselves predict the tumor phenotype. Analysis of the expressed proteins in a tumor and their modification states reveals if and how these mutations are translated to the functional level. It is already known that proteomic changes including posttranslational modifications are crucial drivers of oncogenesis, but proteomics technology has only recently become comparable in depth and accuracy to RNAseq. These advances also allow the rapid and highly sensitive analysis of formalin-fixed and paraffin-embedded biobank tissues, on both the proteome and phosphoproteome levels. In this perspective, pioneering mass spectrometry-based proteomic studies are highlighted that pave the way toward clinical implementation. It is argued that proteomics and phosphoproteomics could provide the missing link to make omics analysis actionable in the clinic.

Combined MEK and BCL-2/XL Inhibition Is Effective in High-Grade Serous Ovarian Cancer Patient-Derived Xenograft Models and BIM Levels Are Predictive of Responsiveness

Most patients with late-stage high-grade serous ovarian cancer (HGSOC) initially respond to chemotherapy but inevitably relapse and develop resistance, highlighting the need for novel therapies to improve patient outcomes. The MEK/ERK pathway is activated in a large subset of HGSOC, making it an attractive therapeutic target. Here, we systematically evaluated the extent of MEK/ERK pathway activation and efficacy of pathway inhibition in a large panel of well-annotated HGSOC patient-derived xenograft models. The vast majority of models were nonresponsive to the MEK inhibitor cobimetinib (GDC-0973) despite effective pathway inhibition. Proteomic analyses of adaptive responses to GDC-0973 revealed that GDC-0973 upregulated the proapoptotic protein BIM, thus priming the cells for apoptosis regulated by BCL2-family proteins. Indeed, combination of both MEK inhibitor and dual BCL-2/XL inhibitor (ABT-263) significantly reduced cell number, increased cell death, and displayed synergy in vitro in most models. In vivo, GDC-0973 and ABT-263 combination was well tolerated and resulted in greater tumor growth inhibition than single agents. Detailed proteomic and correlation analyses identified two subsets of responsive models-those with high BIM at baseline that was increased with MEK inhibition and those with low basal BIM and high pERK levels. Models with low BIM and low pERK were nonresponsive. Our findings demonstrate that combined MEK and BCL-2/XL inhibition has therapeutic activity in HGSOC models and provide a mechanistic rationale for the clinical evaluation of this drug combination as well as the assessment of the extent to which BIM and/or pERK levels predict drug combination effectiveness in chemoresistant HGSOC.

An evolving story of the metastatic voyage of ovarian cancer cells: cellular and molecular orchestration of the adipose-rich metastatic microenvironment

Metastasis is a complex multistep process that involves critical interactions between cancer cells and a variety of stromal components in the tumor microenvironment, which profoundly influence the different aspects of the metastatic cascade and organ tropism of disseminating cancer cells. Ovarian cancer is the most lethal gynecological malignancy and is characterized by peritoneal disseminated metastasis. Evidence has demonstrated that ovarian cancer possesses specific metastatic tropism for the adipose-rich omentum, which has a pivotal role in the creation of the metastatic tumor microenvironment in the intraperitoneal cavity. Considering the distinct biology of ovarian cancer metastasis, the elucidation of the cellular and molecular mechanisms underlying the reciprocal interplay between ovarian cancer cells and surrounding stromal cell types in the adipose-rich metastatic microenvironment will provide further insights into the development of novel therapeutic approaches for patients with advanced ovarian cancer. Herein, we review the biological mechanisms that regulate the highly orchestrated crosstalk between ovarian cancer cells and various cancer-associated stromal cells in the metastatic tumor microenvironment with regard to the omentum by illustrating how different stromal cells concertedly contribute to the development of ovarian cancer metastasis and metastatic tropism for the omentum.

Prognosis Analysis of Histone Deacetylases mRNA Expression in Ovarian Cancer Patients

Histone deacetylases modulate the dynamic balance of histone acetylation and deacetylation in cells, which participate in epigenetic regulations. Accumulated evidence has demonstrated that histone deacetylases are associated with angiogenesis, cell proliferation and survival in a variety of human cancers. However, the expression and distinct prognostic value of histone deacetylases in ovarian cancer have not been well elucidated. In the present study, we collected the overall survival (OS), progress free survival (PFS), and histone deacetylases (HDAC1-11) mRNA expression in ovarian cancer from the Kaplan-Meier plotter online database. We investigated the relationship between histone deacetylases mRNA level and the clinicopathological parameters of the ovarian cancer patients, such as histology subtypes, clinical stages, grades and TP53 mutation. Our analysis data showed that over-expression of HDAC1, HDAC2, HDAC4, HDAC5 and HDAC11 were correlated to poor overall survival and unfavorable progress free survival in all ovarian cancer patients. Notably, the higher level of HDAC11 was associated with the worse OS and PFS for serous/ stage III+IV/ grade III/ TP53 mutation ovarian cancer patients. In conclusion, HDACs may play a crucial role in the prognosis of ovarian cancer, but it is worth noting that HDAC11 may be a biomarker for poor prognosis in ovarian cancer patients.

Cyclin D1 silencing impairs DNA double strand break repair, sensitizes BRCA1 wildtype ovarian cancer cells to olaparib

OBJECTIVE

Poly(ADP-ribose) polymerase inhibitors (PARPi) are active in cancer cells that have impaired repair of DNA by the homologous recombination (HR) pathway. Strategies that disrupt HR may sensitize HR-proficient tumors to PARP inhibition. As a component of the core cell cycle machinery, cyclin D1 has unexpected function in DNA repair, suggesting that targeting cyclin D1 may represent a plausible strategy for expanding the utility of PARPi in ovarian cancer.

METHODS

BRCA1 wildtype ovarian cancer cells (A2780 and SKOV3) were treated with a combination of CCND1 siRNA and olaparib in vitro. Cell viability was assessed by MTT. The effects of the combined treatment on DNA damage repair and cell cycle progression were examined to dissect molecular mechanisms. In vivo studies were performed in an orthotopic ovarian cancer mouse model. Animals were treated with a combination of lentivirus-mediated CCND1 shRNA and olaparib or olaparib plus scrambled shRNA. Molecular downstream effects were examined by immunohistochemistry.

RESULTS

Silencing of cyclin D1 sensitized ovarian cancer cells to olaparib through interfering with RAD51 accumulation and inducing cell cycle G0/G1 arrest. Treatment of lentivirus-mediated CCND1-shRNA in nude mice statistically significantly augmented the olaparib response (mean tumor weight ± SD, CCND1-shRNA plus olaparib vs scrambled shRNA plus olaparib: 0.172 ± 0.070 g vs 0.324 ± 0.044 g, P< 0.05).

CONCLUSIONS

Silencing of cyclin D1 combined with olaparib may lead to substantial benefit for ovarian cancer management by mimicking a BRCAness phenotype, and induction of G0/G1 cell cycle arrest.