Molecular changes in endometriosis-associated ovarian clear cell carcinoma

Endometrioid ovarian carcinoma landscape: pathological and molecular characterization

Endometrioid ovarian cancers (EOvC) are usually managed as serous tumors. In this study, we conducted a comprehensive molecular investigation to uncover the distinct biological characteristics of EOvC. This retrospective multicenter study involved patients from three European centers. We collected clinical data and formalin-fixed paraffin-embedded (FFPE) samples for analysis at the DNA level using panel-based next-generation sequencing and array-comparative genomic hybridization. Additionally, we examined mRNA expression using NanoString nCounter® and protein expression through tissue microarray. We compared EOvC with other ovarian subtypes and uterine endometrioid tumors. Furthermore, we assessed the impact of molecular alterations on patient outcomes, including progression-free survival (PFS) and overall survival (OS). Preliminary analysis of clinical data from 668 patients, including 86 (12.9%) EOvC, revealed more favorable prognosis for EOvC compared with serous ovarian carcinoma (5-year OS of 60% versus 45%; P = 0.001) driven by diagnosis at an earlier stage. Immunohistochemistry and copy number alteration (CNA) profiles of 43 cases with clinical data and FFPE samples available indicated that EOvC protein expression and CNA profiles were more similar to endometrioid endometrial tumors than to serous ovarian carcinomas. EOvC exhibited specific alterations, such as lower rates of PTEN loss, mutations in DNA repair genes, and P53 abnormalities. Survival analysis showed that patients with tumors harboring loss of PTEN expression had worse outcomes (median PFS 19.6 months vs. not reached; P = 0.034). Gene expression profile analysis confirmed that EOvC differed from serous tumors. However, comparison to other rare subtypes of ovarian cancer suggested that the EOvC transcriptomic profile was close to that of ovarian clear cell carcinoma. Downregulation of genes involved in the PI3K pathway and DNA methylation was observed in EOvC. In conclusion, EOvC represents a distinct biological entity and should be regarded as such in the development of specific clinical approaches.

Oncogenic activation of EEF1A2 expression: a journey from a putative to an established oncogene

Protein synthesis via translation is a central process involving several essential proteins called translation factors. Although traditionally described as cellular "housekeepers," multiple studies have now supported that protein initiation and elongation factors regulate cell growth, apoptosis, and tumorigenesis. One such translation factor is eukaryotic elongation factor 1 alpha 2 (EEF1A2), a member of the eukaryotic elongation factor family, which has a canonical role in the delivery of aminoacyl-tRNA to the A-site of the ribosome in a guanosine 5'-triphosphate (GTP)-dependent manner. EEF1A2 differs from its closely related isoform, EEF1A1, in tissue distribution. While EEF1A1 is present ubiquitously, EEF1A2 replaces it in specialized tissues. The reason why certain specialized tissues need to essentially switch EEF1A1 expression altogether with EEF1A2 remains to be answered. Abnormal "switch on" of the EEF1A2 gene in normal tissues is witnessed and is seen as a cause of oncogenic transformation in a wide variety of solid tumors. This review presents the journey of finding increased expression of EEF1A2 in multiple cancers, establishing molecular mechanism, and exploring it as a target for cancer therapy. More precisely, we have compiled studies in seven types of cancers that have reported EEF1A2 overexpression. We have discussed the effect of aberrant EEF1A2 expression on the oncogenic properties of cells, signaling pathways, and interacting partners of EEF1A2. More importantly, in the last part, we have discussed the unique potential of EEF1A2 as a therapeutic target. This review article gives an up-to-date account of EEF1A2 as an oncogene and can draw the attention of the scientific community, attracting more research.

Upregulated PPP1R14B is connected to cancer progression and immune infiltration in kidney renal clear cell carcinoma

BACKGROUND

Protein phosphatase 1 regulatory subunit 14B (PPP1R14B) is an oncogenic gene found in a variety of tumors, but its role in the prognosis and development of kidney renal clear cell carcinoma (KIRC) remains unknown. Our study aimed to determine whether PPP1R14B could be a prognostic biomarker for KIRC and its role in the development of KIRC.

METHODS

In this work, we used The Cancer Genome Atlas (TCGA) database to explore the expression of PPP1R14B in tumor tissues, its relationship with the prognosis of tumor patients, and its role in tumor occurrence and development. We validated our findings using the International Cancer Genome Consortium (ICGC) cohort, our clinical samples, and in vitro experiments.

RESULTS

PPP1R14B was upregulated in KIRC compared to adjacent normal tissue. Moreover, multivariate analysis revealed that upregulated PPP1R14B expression was an independent risk factor for KIRC progression. High-PPP1R14B groups had shorter overall survival (OS) and disease-free survival (DFS) in TCGA and ICGC cohorts. We used Cell Counting Kit-8 (CCK8) and scratch wound healing assay to explore the proliferation and migration of KIRC cells following PPP1R14B knockdown. Our results indicated that PPP1R14B knockdown significantly reduced the proliferation and migration of KIRC cells in vitro. We also explored the possible cellular mechanisms of PPP1R14B through the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene ontology (GO) analysis, and TISIDB analysis. The function enrich analysis revealed that PPP1R14B-related genes were mainly enriched in purine metabolism and the macromolecule catabolic process. PPP1R14B expression was associated with tumor-infiltrating immune cells (TIICs) in the TCGA cohort, and the results of single-cell RNA-seq (scRNA) further demonstrated that PPP1R14B expression was associated with the enhanced infiltration of CD8 + T lymphocytes.

CONCLUSION

PPP1R14B may serve as a prognostic biomarker in KIRC, affect purine metabolism, activate immune infiltration, and promote KIRC cell migration.

PHI-1, an Endogenous Inhibitor Protein for Protein Phosphatase-1 and a Pan-Cancer Marker, Regulates Raf-1 Proteostasis

Raf-1, a multifunctional kinase, regulates various cellular processes, including cell proliferation, apoptosis, and migration, by phosphorylating MAPK/ERK kinase and interacting with specific kinases. Cellular Raf-1 activity is intricately regulated through pathways involving the binding of regulatory proteins, direct phosphorylation, and the ubiquitin-proteasome axis. In this study, we demonstrate that PHI-1, an endogenous inhibitor of protein phosphatase-1 (PP1), plays a pivotal role in modulating Raf-1 proteostasis within cells. Knocking down endogenous PHI-1 in HEK293 cells using siRNA resulted in increased cell proliferation and reduced apoptosis. This heightened cell proliferation was accompanied by a 15-fold increase in ERK1/2 phosphorylation. Importantly, the observed ERK1/2 hyperphosphorylation was attributable to an upregulation of Raf-1 expression, rather than an increase in Ras levels, Raf-1 Ser338 phosphorylation, or B-Raf levels. The elevated Raf-1 expression, stemming from PHI-1 knockdown, enhanced EGF-induced ERK1/2 phosphorylation through MEK. Moreover, PHI-1 knockdown significantly contributed to Raf-1 protein stability without affecting Raf-1 mRNA levels. Conversely, ectopic PHI-1 expression suppressed Raf-1 protein levels in a manner that correlated with PHI-1's inhibitory potency. Inhibiting PP1 to mimic PHI-1's function using tautomycin led to a reduction in Raf-1 expression. In summary, our findings highlight that the PHI-1-PP1 signaling axis selectively governs Raf-1 proteostasis and cell survival signals.

Endometriosis-Associated Ovarian Carcinomas: How PI3K/AKT/mTOR Pathway Affects Their Pathogenesis

Ovarian clear cell (OCCC) and endometrioid (EnOC) carcinomas are often subsumed under the umbrella term "endometriosis-associated ovarian cancer" (EAOC), since they frequently arise from ectopic endometrium settled in the ovaries. The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway is known to be aberrantly activated both in endometriosis and EAOC; however, its role in the progression of endometriosis to ovarian cancer remains unclear. In fact, cancer-associated alterations in the mTOR pathway may be found in normal uterine epithelium, likely acting as a first step towards ovarian cancer, through the intermediary stage of endometriosis. This review aims to summarize the current knowledge regarding mTOR signaling dysregulation in the uterine endometrium, endometriosis, and EAOC while focusing on the interconnections between the PI3K/AKT/mTOR pathway and other signaling molecules that give rise to synergistic molecular mechanisms triggering ovarian cancer development in the presence of endometriosis.

PPP1R14B is a diagnostic prognostic marker in patients with uterine corpus endometrial carcinoma

Uterine corpus endometrial carcinoma (UCEC) is one of the most common malignancies of the female genital tract. A recently discovered protein-coding gene, PPP1R14B, can inhibit protein phosphatase 1 (PP1) as well as different PP1 holoenzymes, which are important proteins regulating cell growth, the cell cycle, and apoptosis. However, the association between PPP1R14B expression and UCEC remains undefined. The expression profiles of PPP1R14B in multiple cancers were analysed based on TCGA and GTE databases. Then, PPP1R14B expression in UCEC was investigated by gene differential analysis and single gene correlation analysis. In addition, we performed gene ontology term analysis, Kyoto Encyclopedia of Genes and Genomes pathway analysis, gene set enrichment analysis, and Kaplan-Meier survival analysis to predict the potential function of PPP1R14B and its role in the prognosis of UCEC patients. Then, a tool for predicting the prognosis of UCEC, namely, a nomogram model, was constructed. PPP1R14B expression was higher in UCEC tumour tissues than in normal tissues. The results revealed that PPP1R14B expression was indeed closely associated with tumour development. The results of Kaplan-Meier plotter data indicated that patients with high PPP1R14b expression had poorer overall survival, disease-specific survival, and progression-free interval than those with low expression. A nomogram based on the results of multifactor Cox regression was generated. PPP1R14B is a key player in UCEC progression, is associated with a range of adverse outcomes, and can serve as a prognostic marker in the clinic.

Protein Phosphatase 1 Subunit PPP1R14B Stabilizes STMN1 to Promote Progression and Paclitaxel Resistance in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) represents the most lethal subtype of breast cancer due to its aggressive clinical features and the lack of effective therapeutic targets. To identify novel approaches for targeting TNBC, we examined the role of protein phosphatases in TNBC progression and chemoresistance. Protein phosphatase 1 regulatory subunit 14B (PPP1R14B), a poorly defined member of the protein phosphatase 1 regulatory subunits, was aberrantly upregulated in TNBC tissues and predicted poor prognosis. PPP1R14B was degraded mainly through the ubiquitin-proteasome pathway. RPS27A recruited deubiquitinase USP9X to deubiquitinate and stabilize PPP1R14B, resulting in overexpression of PPP1R14B in TNBC tissues. Gain- and loss-of-function assays demonstrated that PPP1R14B promoted TNBC cell proliferation, colony formation, migration, invasion, and resistance to paclitaxel in vitro. PPP1R14B also induced xenograft tumor growth, lung metastasis, and paclitaxel resistance in vivo. Mechanistic investigations revealed that PPP1R14B maintained phosphorylation and stability of oncoprotein stathmin 1 (STMN1), a microtubule-destabilizing phosphoprotein critically involved in cancer progression and paclitaxel resistance, which was dependent on PP1 catalytic subunits α and γ. Importantly, the tumor-suppressive effects of PPP1R14B deficiency could be partially rescued by ectopic expression of wild-type but not phosphorylation-deficient STMN1. Moreover, PPP1R14B decreased STMN1-mediated α-tubulin acetylation, microtubule stability, and promoted cell-cycle progression, leading to resistance of TNBC cells to paclitaxel. Collectively, these findings uncover a functional and mechanistic role of PPP1R14B in TNBC progression and paclitaxel resistance, indicating PPP1R14B is a potential therapeutic target for TNBC.

SIGNIFICANCE

PPP1R14B upregulation induced by RPS27A/USP9X in TNBC increases STMN1 activity, leading to cancer progression and paclitaxel resistance.

Comprehensive analysis of protein phosphatase 1 regulatory inhibitor subunit 14B, a molecule related to tumorigenesis, poor prognosis, and immune cell infiltration in lung adenocarcinoma

OBJECTIVE

To explore the relationship between Protein Phosphatase 1 Regulatory Inhibitor Subunit 14B (PPP1R14B) and the occurrence of lung adenocarcinoma (LUAD).

METHOD

PPP1R14B expression was investigated using various databases, and its molecular functions and pathways were evaluated using Gene Set Variation Analysis (GSVA) and Gene Set Enrichment Analysis (GSEA). Then, the correlation between tumor mutations and PPP1R14B expression was analyzed. Furthermore, the regulation network and expression pathway axes of PPP1R14B were constructed. The correlation analysis between PPP1R14B and immune cell infiltration was performed using deconvolution algorithm analysis and the Tumor Immune Dysfunction and Exclusion (TIDE) algorithm. Finally, quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemical (IHC) staining of the clinical samples were used for expression validation.

RESULTS

PPP1R14B showed high expression in tumor tissue. PPP1R14B was associated with T and N stages and poor prognosis and was linked to the cell cycle, DNA repair, and low immune response. High PPP1R14B expression was associated with high tumor mutation rates. The upstream and downstream genes of PPP1R14B were identified, along with the construction of a protein-protein interaction network (PPI network) and the expression pathway axes of PPP1R14B. PPP1R14B expression was associated with poor immune cell infiltration and a negative correlation between PPP1R14B and mast cell and eosinophil infiltration.

CONCLUSION

This study reveals high PPP1R14B expression in LUAD, its contribution to poor prognosis, molecular function, biological pathways, and impact on immune cell infiltration, and provides great insight into the role of PPP1R14B in LUAD tumorigenesis.

Review the progression of ovarian clear cell carcinoma from the perspective of genomics and epigenomics

Ovarian clear cell carcinoma (OCCC) is a rare subtype of epithelial ovarian cancer with unique molecular characteristics, specific biological and clinical behavior, poor prognosis and high resistance to chemotherapy. Pushed by the development of genome-wide technologies, our knowledge about the molecular features of OCCC has been considerably advanced. Numerous studies are emerging as groundbreaking, and many of them are promising treatment strategies. In this article, we reviewed studies about the genomics and epigenetics of OCCC, including gene mutation, copy number variations, DNA methylation and histone modifications.

Molecular Subclasses of Clear Cell Ovarian Carcinoma and Their Impact on Disease Behavior and Outcomes

PURPOSE

To identify molecular subclasses of clear cell ovarian carcinoma (CCOC) and assess their impact on clinical presentation and outcomes.

EXPERIMENTAL DESIGN

We profiled 421 primary CCOCs that passed quality control using a targeted deep sequencing panel of 163 putative CCOC driver genes and whole transcriptome sequencing of 211 of these tumors. Molecularly defined subgroups were identified and tested for association with clinical characteristics and overall survival.

RESULTS

We detected a putative somatic driver mutation in at least one candidate gene in 95% (401/421) of CCOC tumors including ARID1A (in 49% of tumors), PIK3CA (49%), TERT (20%), and TP53 (16%). Clustering of cancer driver mutations and RNA expression converged upon two distinct subclasses of CCOC. The first was dominated by ARID1A-mutated tumors with enriched expression of canonical CCOC genes and markers of platinum resistance; the second was largely comprised of tumors with TP53 mutations and enriched for the expression of genes involved in extracellular matrix organization and mesenchymal differentiation. Compared with the ARID1A-mutated group, women with TP53-mutated tumors were more likely to have advanced-stage disease, no antecedent history of endometriosis, and poorer survival, driven by their advanced stage at presentation. In women with ARID1A-mutated tumors, there was a trend toward a lower rate of response to first-line platinum-based therapy.

CONCLUSIONS

Our study suggests that CCOC consists of two distinct molecular subclasses with distinct clinical presentation and outcomes, with potential relevance to both traditional and experimental therapy responsiveness. See related commentary by Lheureux, p. 4838.

In vitro assessment of roles of PPP1R14B in cervical and endometrial cancer

Cervical and endometrial cancers are common gynecologic cancers. Protein phosphatase 1 regulatory subunit 14B (PPP1R14B) is aberrantly expressed in several tumors, while its functions in cervical and endometrial cancers remain largely uncertain. The differentially expression of PPP1R14B in cervical and endometrial cancers was predicted by GEPIA2 and Human Protein Atlas databases. The diagnostic value was analyzed by AUC curve. The association between PPP1R14B expression and overall survival was predicted using Kaplan-Meier Plotter database. The function of PPP1R14B was investigated according to in vitro assessment. PPP1R14B and phosphorylation level of Akt were analyzed through western blotting. Cell proliferation was investigated by CCK-8 and EdU staining assays. Cell apoptosis was evaluated via TUNEL staining and caspase-3 activity assays. PPP1R14B level was upregulated in cervical and endometrial cancers, and it was associated with diagnosis and worse prognosis. PPP1R14B silencing constrained cell proliferation and promoted cell death in cervical and endometrial cancers cells. PPP1R14B knockdown suppressed activation of the Akt pathway. Re-activation of the Akt signaling reversed the anti-proliferative and cell death-promoting roles of PP1R14B knockdown in cervical and endometrial cancers cells. In conclusion, PPP1R14B knockdown represses cell proliferation and facilitates cell death by inhibiting the activation of the Akt signaling in cervical and endometrial cancers.

PPP1R14B Is a Prognostic and Immunological Biomarker in Pan-Cancer

Recent studies have shown that PPP1R14B was highly expressed in tumor tissues and patients with high expression of PPP1R14B had poor survival rates. However, the function and mechanisms of PPP1R14B in tumor progression remain ill defined. There was also lack of pan-cancer evidence for the relationship between PPP1R14B and various tumor types based on abundant clinical data. We used the TCGA project and GEO databases to perform pan-cancer analysis of PPP1R14B, including expression differences, correlations between expression levels and survival, genetic alteration, immune infiltration, and relevant cellular pathways, to investigate the functions and potential mechanisms of PPP1R14B in the pathogenesis or clinical prognosis of different cancers. Herein, we found that PPP1R14B was involved in the prognosis of pan-cancer and closely related to immune infiltration. Increased PPP1R14B expression correlated with poor prognosis and increased immune infiltration levels in myeloid-derived suppressor cells (MDSCs). Our studies suggest that PPP1R14B can be used as a prognostic biomarker for pan-cancer. Our findings may provide an antitumor strategy targeting PPP1R14B, including manipulation of tumor cell growth or the tumor microenvironment, especially myeloid-derived suppressor cell infiltration.

Does the "Devil" originate from the fallopian tubes?

Epithelial ovarian cancer (OC) is a heterogeneous disease and continues to be mostly diagnosed in advanced stages. The high lethality, the high rate of platinum-resistance, and the poor survival outcomes are the principal factors for categorizing OC among the most aggressive gynecological cancers. Only recently, a substantial progress has been made in our latest understanding of the origins of OC, particularly of high-grade serous histology. For a long time, the accumulation of genetic alterations in epithelial single layer cells of ovarian cysts caused by cyclic ovulations was considered as the most important driver and the long-standing dogma of ovarian tumorigenesis. Besides, the unique biological features and high histological heterogeneity of OC did not support this hypothesis. Indeed, various extra-ovarian cells of origin and multiple sites to each histotype were proposed, supported by cogent evidence from clinical cohorts and animal studies. In light of this enigma, this review was conducted to discuss the recent evidence supporting the revised origins of ovarian carcinoma histotypes with a particular focus on high-grade serous OC which may impact diagnostic and preventive approaches.

Endometriosis-associated Ovarian Clear Cell Carcinoma: A Special Entity?

Endometriosis is an estrogen-dependent disease, which serves as a precursor of ovarian cancer, especially clear cell carcinoma (OCCC) and endometrial carcinoma. Although micro-environmental factors such as oxidative stress, immune cell dysfunction, inflammation, steroid hormones, and stem cells required for malignant transformation have been found in endometriosis, the exact carcinogenic mechanism remains unclear. Recent research suggest that many putative driver genes and aberrant pathways including ARID1A mutations, PIK3CA mutations, MET activation, HNF-1β activation, and miRNAs dysfunction, play crucial roles in the malignant transformation of endometriosis to OCCC. The clinical features of OCCC are different from other histological types. Patients usually present with a large, unilateral pelvic mass, and occasionally have thromboembolic vascular complications. OCCC patients are easier to be resistant to chemotherapy, have a worse prognosis, and are usually difficult to treat. To improve the survival of OCCC patients, it is necessary to better understand its specific carcinogenic mechanism and explore new treatment strategy, including molecular target.

Endometriosis-associated cancer

Endometriosis will affect about 10% of the female population and not only can it significantly impact adversely on quality of life and result in infertility, but data are accumulating that malignant transformation is an important consideration. Endometriosis can be histologically typical or atypical, ovarian, superficial peritoneal or deep infiltrating. The precursor for malignant transformation appears to be the ovarian atypical endometriosis component. Ovarian cancer is the most important associated cancer, primarily endometrioid and clear cell cancer. These are the only subtypes wherein a direct clonal relationship between endometriosis, as a direct precursor, and cancer has been made. There is no substantive evidence to support an altered association of borderline cancers of the ovary, serous ovarian cancers and breast, endometrial or cervical cancers. This review provides an overview of the prevailing data pertaining to the molecular and genetic aberrations that accompany the transformation of atypical endometriosis to malignancy and the accumulated epidemiologic evidence which supports the association.

Genomics of Endometriosis: From Genome Wide Association Studies to Exome Sequencing

This review aims at better understanding the genetics of endometriosis. Endometriosis is a frequent feminine disease, affecting up to 10% of women, and characterized by pain and infertility. In the most accepted hypothesis, endometriosis is caused by the implantation of uterine tissue at ectopic abdominal places, originating from retrograde menses. Despite the obvious genetic complexity of the disease, analysis of sibs has allowed heritability estimation of endometriosis at ~50%. From 2010, large Genome Wide Association Studies (GWAS), aimed at identifying the genes and loci underlying this genetic determinism. Some of these loci were confirmed in other populations and replication studies, some new loci were also found through meta-analyses using pooled samples. For two loci on chromosomes 1 (near CCD42) and chromosome 9 (near CDKN2A), functional explanations of the SNP (Single Nucleotide Polymorphism) effects have been more thoroughly studied. While a handful of chromosome regions and genes have clearly been identified and statistically demonstrated as at-risk for the disease, only a small part of the heritability is explained (missing heritability). Some attempts of exome sequencing started to identify additional genes from families or populations, but are still scarce. The solution may reside inside a combined effort: increasing the size of the GWAS designs, better categorize the clinical forms of the disease before analyzing genome-wide polymorphisms, and generalizing exome sequencing ventures. We try here to provide a vision of what we have and what we should obtain to completely elucidate the genetics of this complex disease.

Exploration of the Modulatory Property Mechanism of ELeng Capsule in the Treatment of Endometriosis Using Transcriptomics Combined With Systems Network Pharmacology

Endometriosis is a common gynecological disease and causes severe chronic pelvic pain and infertility. Growing evidence showed that traditional Chinese medicine (TCM) plays an active role in the treatment of endometriosis. ELeng Capsule (ELC) is a Chinese medicine formula used for the treatment of endometriosis for several years. However, the mechanisms of ELC have not been fully characterized. In this study, network pharmacology and mRNA transcriptome analysis were used to study various therapeutic targets in ELC. As a result, 40 compounds are identified, and 75 targets overlapped with endometriosis-related proteins. The mechanism of ELC for the treatment of endometriosis is based on the function modules of inducing apoptosis, inhibiting angiogenesis, and regulating immunity mainly through signaling molecules and interaction (neuroactive ligand-receptor interaction), immune system-associated pathways (toll-like receptor signaling pathway), vascular endothelial growth factor (VEGF) signaling, and MAPK signaling pathway based on network pharmacology. In addition, based on RNA-sequence analysis, we found that the mechanism of ELC was predominantly associated with the regulation of the function modules of actin and cytoskeleton, epithelial-mesenchymal transition (EMT), focal adhesion, and immunity-associated pathways. In conclusion, ELC exerted beneficial effects on endometriosis, and the potential mechanism could be realized through functional modules, such as inducing apoptosis and regulating angiogenesis, cytoskeleton, and EMT. This work not only provides insights into the therapeutic mechanism of TCM for treating endometriosis but also offers an efficient way for drug discovery and development from herbal medicine.

LINC00466 Impacts Cell Proliferation, Metastasis and Sensitivity to Temozolomide of Glioma by Sponging miR-137 to Regulate PPP1R14B Expression

Purpose

LINC00466 is a newfound long non-coding RNA (lncRNA) that has been rarely explored in cancers. However, the specific role and molecular mechanism of LINC00466 in glioma remain to be further elucidated.

Methods

Bioinformatic analysis was used to screen differentially expressed genes. Quantitative real-time PCR (qRT-PCR) was used to determine the expression of LINC00466, microRNA-137 (miR-137) and protein phosphatase 1 regulatory subunit 14B (PPP1R14B). Dual-luciferase reporter gene assay and RNA binding protein Immunoprecipitation (RIP) assays were employed to verify the binding relationship among LINC00466, miR-137 and PPP1R14B. The sensitivity of glioma cells to temozolomide (TMZ) was measured by cell counting kit-8 (CCK8) assay. The xenograft nude models were used to test the effects of LINC00466 on glioma tumor growth in vivo.

Results

Highly expressed LINC00466 and PPP1R14B and lowly expressed miR-137 were eventually revealed in glioma tissues. Overexpression of LINC00466 could promote proliferation, metastasis and drug sensitivity to TMZ of glioma cells. LINC00466 could bind to miR-137, and up-regulation of miR-137 could attenuate the enhancing effects caused by LINC00466 overexpression. We took a further step and found that miR-137 could bind to PPP1R14B. Besides, LINC00466 could function as a sponge to miR-137 to regulate PPP1R14B. In addition, overexpression of LINC00466 could promote tumor growth in vivo.

Conclusion

These findings validate LINC00466 could restrain the miR-137 expression to up-regulate PPP1R14B and therefore promote proliferation, metastasis and resistance to TMZ of glioma.

Ovarian endometriosis, a precursor of ovarian cancer: Histological aspects, gene expression and microRNA alterations (Review)

Ovarian endometriosis is a frequent chronic gynecological disease with an uncertain evolution regarding its progression or association with ovarian malignant lesions. The present review summarized the histological aspects, gene expression and microRNA (miRNA/miR) alterations associated with ovarian endometriosis and cancer and their possible interaction. The endometriosis-ovarian cancer interaction has been proposed by certain researchers as a single entity. Histological results indicated that endometriosis has been in different circumstances coexisting with ovarian cancer, with reference to endometrioid and clear cell carcinoma. Endometriosis with moderate and severe atypia can influence cell proliferation and architecture, resulting in a possible malignant transformation. Gene expression analysis indicated that the pathologies of both endometriosis and ovarian cancer are characterized by genetic instability from a molecular point of view, as several important genetic mutations, including ARID1A, PI3KCA, PTEN, BRCA1, BRCA2, TP53 and KRAS genes, were identified. miRNA alterations have been implicated in the regulation of gene expression. Common dysregulated miRNAs, such as miR-331, miR-335, miR-891, miR-548, miR-124, miR-148, miR-215, miR-192, miR-337, miR-153, miR-155, miR-144, miR-221 and miR-3688 were extensively investigated in understanding endometriosis and ovarian cancer evolution. From a combined viewpoint including histological aspects, gene expression and miRNA alterations, it is reasonable to speculate that endometriosis is associated with ovarian cancer. Ovarian endometriosis lesions may present a risk for ovarian malignant lesions, which supports a model of endometriosis as a malignant precursor. However, the endometriosis-ovarian cancer association is not widely accepted in the literature and additional studies are required to validate this association.

Tetraspanin 1 promotes endometriosis leading to ovarian clear cell carcinoma

Ovarian clear cell carcinoma (OCCC) reportedly develops from endometriosis. However, the molecular mechanism underlying its malignant progression to OCCC remains elusive. This study aimed to identify an essential gene in the malignant transformation of endometriosis to OCCC. We performed RNA sequencing in formalin‐fixed, paraffin‐embedded (FFPE) tissues of endometriosis (n = 9), atypical endometriosis (AtyEm) (n = 18), adjacent endometriosis to OCCC (AdjEm) (n = 7), and OCCC (n = 17). We found that tetraspanin 1 (TSPAN1) mRNA level was significantly increased by 2.4‐ (DESeq2) and 3.4‐fold (edgeR) in AtyEm and by 80.7‐ (DESeq2) and 101‐fold (edgeR) in OCCC relative to endometriosis. We confirmed that TSPAN1 protein level was similarly overexpressed in OCCC tissues and cell lines. In immortalized endometriosis cell lines, TSPAN1 overexpression enhanced cell growth and invasion. Mechanistically, TSPAN1 triggered AMP‐activated protein kinase (AMPK) activity, promoting endometriosis and cell growth. Upregulated levels of TSPAN1 are considered an early event in the development of high‐risk endometriosis that could progress to ovarian cancer. Our study suggests the potential of TSPAN1 as a screening candidate for high‐risk endometriosis.

Malignant Transformation and Associated Biomarkers of Ovarian Endometriosis: A Narrative Review

This review focuses on pathogenesis of endometriosis, its possible biomarkers and role in endometriosis-associated ovarian cancer. We analyzed various databases to obtain new insights, theories, and biomarkers associated with endometriosis. There are several theories of endometriosis development and biomarker changes including atypical forms. A number of studies have attempted to establish specific, reliable biomarkers to help diagnose endometriosis and endometriosis-associated diseases on the basis of different pathogenetic pathways. Nevertheless, despite intensive research extending even to the molecular level, the origin, natural history, malignant transformation, and laboratory management of endometriosis and related diseases are not yet clearly defined. Therefore, early laboratory diagnoses of endometriosis, its atypical form, and endometriosis-associated ovarian tumors are important problems that require further study in the context of advanced therapeutic strategies to provide maximal health benefits to patients.

The impact of ultraviolet- and infrared-based laser microdissection technology on phosphoprotein detection in the laser microdissection-reverse phase protein array workflow

Reversible protein phosphorylation represents a key mechanism by which signals are transduced in eukaryotic cells. Dysregulated phosphorylation is also a hallmark of carcinogenesis and represents key drug targets in the precision medicine space. Thus, methods that preserve phosphoprotein integrity in the context of clinical tissue analyses are crucially important in cancer research. Here we investigated the impact of UV laser microdissection (UV LMD) and IR laser capture microdissection (IR LCM) on phosphoprotein abundance of key cancer signaling protein targets assessed by reverse-phase protein microarray (RPPA). Tumor epithelial cells from consecutive thin sections obtained from four high-grade serous ovarian cancers were harvested using either UV LMD or IR LCM methods. Phosphoprotein abundances for ten phosphoproteins that represent important drug targets were assessed by RPPA and revealed no significant differences in phosphoprotein integrity from those obtained using higher-energy UV versus the lower-energy IR laser methods.

Identification of novel mutations of ovarian cancer-related genes from RNA-sequencing data for Japanese epithelial ovarian cancer patients

Ovarian cancer has the highest mortality rate among gynecological cancers. Gene mutations are involved in the carcinogenesis, metastasis, and therapeutic response in ovarian cancer. However, the variety and proportion of gene mutation is not fully analyzed in Japanese ovarian cancer patients, especially, in those with recurrent tumors. In the present study, RNA-sequencing was performed for 32 clinical ovarian specimens obtained from 24 Japanese patients (24 primary cancer specimens and 8 recurrent specimens paired with corresponding primary cancer specimens). Mutations in 24 primary specimens were analyzed by comparing the sequence data mapped on RefSeq genes with those in the public online databases BRCA Exchange, COSMIC, ClinVar, and cBioportal. Mutations were observed in TP53 in 16 specimens (67%), BRCA1 in 9 (38%), BRCA2 in 13 (54%), ARID1A in 3 (13%), PIK3CA in 2 (8%), KRAS in 1 (4%), PTEN in 1 (4%), and CTNNB1 in 1 (4%), excluding synonymous mutations. Among those identified muations, 13 of 14 mutations in TP53, 10 of 11 mutations of BRCA1, 10 of 23 mutation positions of BRCA2, none of 7 mutations of ARID1A, 1 mutation of PIK3CA, and 1 mutation of CTNNB1 were consistent with those reported in the public online databases; however, the other mutations identified were novel. Comparison between matched-paired specimens of primary and recurrent tumors revealed the changes of mutational status in expressed RNAs. RNA-sequencing-based mutation analysis will be useful to reveal ethnic differences of gene mutations in ovarian cancer and to understand the contribution of gene mutations to recurrence.

Endometriosis: The Role of Iron Overload and Ferroptosis

Iron is an essential element for cell survival, and iron deficiency is a known risk factor for many reproductive disorders. Paradoxically, such disorders are also seen more commonly under conditions of iron excess. Here, we focus on the problem of iron overload in women's health, using endometriosis as a model system. We propose (i) that a primary defect in endometriosis is abnormal eutopic endometrium characterized by resistance to ferroptosis, a process of iron-mediated non-apoptotic programmed cell death, which allows cells spread via retrograde menstruation to survive, implant, and establish endometriotic lesions within the abdominal cavity, and (ii) that dysregulated iron homeostasis may be critical to the subsequent pathophysiology of endometriotic lesions with localized iron overload and inflammation. We further investigate the association between endometriosis and hypercholesterolemia and suggest that an interaction between the mevalonate cholesterol biosynthetic pathway and ferroptosis signaling may provide a molecular basis to explain how it is that, in some women, endometrial tissues survive and thrive under ferroptotic pressure, colonize at ectopic sites, and expand into endometriotic lesions.

PTEN and Gynecological Cancers

PTEN is a tumour suppressor gene, and its loss of function is frequently observed in both heritable and sporadic cancers. It is involved in a great variety of biological processes, including maintenance of genomic stability, cell survival, migration, proliferation and metabolism. A better understanding of PTEN activity and regulation has therefore emerged as a subject of primary interest in cancer research. Gynaecological cancers are variously interested by PTEN deregulation and many perspective in terms of additional prognostic information and new therapeutic approaches can be explored. Here, we present the most significant findings on PTEN in gynaecological cancers (ovarian, endometrial, cervical, vulvar and uterine cancer) focusing on PTEN alterations incidence, biological role and clinical implications.

Endometriosis-associated ovarian cancer is a single entity with distinct clinicopathological characteristics

Objective: To compare the clinicopathological features and chemotherapy response of ovarian clear cell carcinoma (CCC) and endometrioid carcinoma (EC) associated with endometriosis or not. Methods: This was a retrospective study of 128 patients diagnosed with CCC and EC from 2002 to 2017. Clinicopathological features and chemotherapy response were analyzed. Results:There were 34 women with endometriosis-associated ovarian cancer (EAOC) and 94 with non-endometriosis associated ovarian cancer (non-EAOC) according to Sampson's and Scott's criteria. The mean diagnosis age in the EAOC group was 48.65 vs. 54.39 years in non-EAOC (p = 0.002). Compared with non-EAOC, the EAOC patients were more likely to have an earlier menarche age (13 vs. 14 years, p = 0.001), a higher incidence of infertility (26.47% vs. 10.64%, p = 0.026), and an earlier stage tumor (91.18% vs. 73.40% in stages I-II, p = 0.032). At a median follow-up time of 32.9 months, overall survival among patients with EAOC was significantly longer (109.8 vs. 47.4 months, p = 0.007). Association with endometriosis (p = 0.033) was the significant favorable prognostic factors associated with survival. However, stratifying by stage, the overall survival advantage of EAOC was not significant. Although EAOC had a better prognosis, no difference was observed in chemotherapy response between the two groups (p = 0.535). Conclusions: The EAOC patients were often diagnosed at a younger age, an earlier stage, and related to nulliparity and infertility. Patients with EAOC had a better prognosis than non-EAOC, early stage rather than association with endometriosis may be the driver of survival.

NADH dehydrogenase complex I is overexpressed in incipient metastatic murine colon cancer cells

Colon cancer is one of the most frequently occurring types of cancers in the world. Primary tumours are treated very efficiently, but the metastatic cases are known to have severe outcomes. Therefore, the aim of the present study was to obtain a greater understanding of the transformation of primary colon cancer cells into metastatic phenotypes. Small changes in protein expression provoke the metastatic phenotype transformation. More sensitive methods to detect small variations are required. A murine colon cancer cell line with metastatic characteristics in a very early phase was created in order to investigate the first steps of transformation using a murine liver metastasis model. The protein expression patterns of metastatic and non-metastatic cells were compared using the stable isotope labelling by amino acids in cell culture method in combination with mass spectrometry. Quantitative proteomics data indicated that nicotinamide adenine dinucleotide hydride (NADH) dehydrogenase complex I was overexpressed in metastatic cells with respect to non-metastatic cells. Since the NADH dehydrogenase complex catalyses the oxidation of NADH to NAD⁺, the functionality of the complex was studied by measuring the amount of NADH. The results revealed that metastatic cells accumulate more NADH and reactive oxygen species. In addition, the mitochondrial membrane potential of metastatic cells was lower than that of non-metastatic cells, indicating that the activity of NADH dehydrogenase and the mitochondrial oxidative chain were decreased in metastatic cells. During the incipient transformation of primary cancer cells, NADH dehydrogenase complex I was overexpressed but then became inactive due to the Warburg effect, which inhibits mitochondrial activity. In the first step of transformation, the high energy demand required in an adverse environment is fulfilled by overexpressing components of the respiratory chain, a fact that should be considered for future anti-metastatic therapies.

Pathogenesis, Genetics, and Genomics of Non-High Grade Serous Ovarian Cancers

The 5 main non-high grade serous epithelial ovarian cancers (clear cell, low grade endometrioid, low grade serous, mucinous, and carcinosarcoma) are discrete in terms of their pathogenesis, molecular biology, and treatment sensitivity. This article reviews the current understanding of their pathogenesis and molecular biology, highlighting areas of uncertainty where future research efforts should be focused.

The Evolution of Estrogen Receptor Signaling in the Progression of Endometriosis to Endometriosis-Associated Ovarian Cancer

To investigate changes in estrogen receptor alpha (ERα) signaling during progression of endometriosis to endometriosis-associated ovarian cancer (EAOC) as a driver of malignant transformation. We procured tissue samples of normal endometrium, endometriosis (benign, atypical, concurrent with EAOC), and EAOC. We evaluated expression of a 236-gene signature of estrogen signaling. ANOVA and unsupervised clustering were used to identify gene expression profiles across disease states. These profiles were compared to profiles of estrogen regulation in cancer models from the Gene Expression Omnibus (GEO). Gene Set Enrichment Analysis (GSEA) was performed to determine whether gene expression in EAOC was consistent with ERα activity. ANOVA revealed 158 differentially expressed genes (q < 0.05) and unsupervised clustering identified five distinct gene clusters. The estrogen signaling profile of EAOC was not consistent with activated ERα in pre-clinical models. Gene set enrichment analysis did not identify signatures of activated ERα in EAOC but instead identified expression patterns consistent with loss of ERα function and development of endocrine resistance. Gene expression data suggest that ERα signaling becomes inactivated throughout the progression of endometriosis to EAOC. The gene expression pattern in EAOC is more consistent with profiles of endocrine resistance.

Endometriosis does not confer improved prognosis in ovarian clear cell carcinoma: a retrospective study at a single institute

BACKGROUND

Considered as the precursor lesion of a subset of ovarian clear cell carcinoma (OCCC), the prognostic role of endometriosis in OCCC patients remains controversial. This study aimed to investigate the prognostic role of coexisting endometriosis in the survival of patients with OCCC, and also sought to identify other prognostic factors.

RESULTS

A total of 125 patients were diagnosed with OCCC during the study period. Of these, 55 (44.0%) patients had coexisting endometriosis. Patients with endometriosis were younger (p = 0.030), had smaller tumor diameter (p = 0.005) and lower preoperative CA125 levels (p = 0.005). More patients with endometriosis had International Federation of Gynecology and Obstetrics (FIGO) stage I disease (83.6% vs. 51.4%, p = 0.000) and exhibited sensitivity to platinum-based regimen (89.6% vs. 66.7%, p = 0.003). Univariate and multivariate analysis revealed that coexisting endometriosis was not a predictor of 5-year overall survival (OS) or progression-free survival (PFS) of OCCC patients. For OS, chemosensitivity was the only useful prognostic factor (Hazards ratio (HR) 109.33, 95% Confidence Interval (CI) 23.46-511.51; p = 0.000). For PFS, the useful prognostic factors were ascites (HR 2.78, 95% CI 1.21-6.47; p = 0.016), FIGO stage (HR 1.61, 95% CI 1.04-2.49; p = 0.033), and chemosensitivity (HR 101.60, 95% CI 29.45-350.49; p = 0.000). Moreover, higher FIGO stage was the only risk factor for resistance to platinum-based chemotherapy (Exp (B) = 0.292, 95% CI 0.123-0.693; p = 0.005).

CONCLUSIONS

In this study, coexisting endometriosis was not a prognostic factor for the survival of OCCC patients. The most important predictor of both 5-year OS and PFS was chemosensitivity to platinum-based regimen, which decreased significantly with increase in FIGO stage.

Analysis of CARD10 and CARD11 somatic mutations in patients with ovarian endometriosis

Endometriosis is a complex and heterogeneous pre-malignant inflammatory disease harboring multiple gene mutations. Previous studies have suggested that caspase recruitment domain family member (CARD)10 and CARD11 mutations may exist in endometriosis. In the present study, a collection of endometriotic lesions and paired peripheral blood from 101 patients with ovarian endometriosis were obtained, and the entire coding sequences of the CARD10 and CARD11 genes were sequenced. Evolutionary conservation analysis and online prediction programs were applied to analyze the disease-causing potential of the identified mutations. A total of 4 novel somatic mutations were identified in 4 out of the 101 (4.0%) samples: 2 in-frame deletions in CARD10 (c.785_790delAGGAGA, p.K272_E273delKE; c.785_802delAGGAGAAGGAGAAGGAGA, p.K272_V277delKEPDNV) and 2 heterozygous missense mutations in CARD11 (c.49G>T, p.D17Y; c.160G>C, p.E54Q). The sample with CARD10 p.K272_E273delKE deletion was obtained from a 47-year-old patient who was also diagnosed with uterine leiomyoma, while the CARD10 p.K272_V277delKEPDNV-mutated sample was from a 43-year-old patient exhibiting a decreased blood eosinophil granulocyte ratio (0.3%) and an elevated serum creatine kinase level (314 U/l). The patient with the CARD11 p.D17Y mutation was 38 years old and exhibited an increased level of cancer antigen 125 (45.4 U/ml), while the patient with the CARD11 p.E54Q mutation was 46 years old and exhibited no other gynecological conditions. Evolutionary conservation analysis and online prediction programs suggested that these mutations may be disease-causing. In summary, 4 novel somatic mutations in the CARD10 and CARD11 genes were identified from amongst 101 cases of ovarian endometriosis for the first time, these mutations may serve active roles in the development of ovarian endometriosis.

Endometriosis Malignant Transformation: Epigenetics as a Probable Mechanism in Ovarian Tumorigenesis

Endometriosis, defined as the presence of ectopic endometrial glands and stroma outside the uterine cavity, is a chronic, hormone-dependent gynecologic disease affecting millions of women across the world, with symptoms including chronic pelvic pain, dysmenorrhea, dyspareunia, dysuria, and subfertility. In addition, there is well-established evidence that, although endometriosis is considered benign, it is associated with an increased risk of malignant transformation, with the involvement of various mechanisms of development. More and more evidence reveals an important contribution of epigenetic modification not only in endometriosis but also in mechanisms of endometriosis malignant transformation, including DNA methylation and demethylation, histone modifications, and miRNA aberrant expressions. In this present review, we mainly summarize the research progress about the current knowledge regarding the epigenetic modifications of the relations between endometriosis malignant transformation and ovarian cancer in an effort to identify some risk factors probably associated with ectopic endometrium transformation.

Epithelialization of mouse ovarian tumor cells originating in the fallopian tube stroma

Epithelial ovarian carcinoma accounts for 90% of all ovarian cancer and is the most deadly gynecologic malignancy. Recent studies have suggested that fallopian tube fimbriae can be the origin of cells for high-grade serous subtype of epithelial ovarian carcinoma (HGSOC). A mouse HGSOC model with conditional Dicer-Pten double knockout (Dicer-Pten DKO) developed primary tumors, intriguingly, from the fallopian tube stroma. We examined the growth and epithelial phenotypes of the Dicer-Pten DKO mouse tumor cells contributable by each gene knockout. Unlike human ovarian epithelial cancer cells that expressed full-length E-cadherin, the Dicer-Pten DKO stromal tumor cells expressed cleaved E-cadherin fragments and metalloproteinase 2, a mixture of epithelial and mesenchymal markers. Although the Dicer-Pten DKO tumor cells lost the expression of mature microRNAs as expected, they showed high levels of tRNA fragment expression and enhanced AKT activation due to the loss of PTEN function. Introduction of a Dicer1-expressing construct into the DKO mouse tumor cells significantly reduced DNA synthesis and the cell growth rate, with concurrent diminished adhesion and ZO1 epithelial staining. Hence, it is likely that the loss of Dicer promoted mesenchymal-epithelial transition in fallopian tube stromal cells, and in conjunction with Pten loss, further promoted cell proliferation and epithelial-like tumorigenesis.

Endometriosis and endometriosis-associated cancers: new insights into the molecular mechanisms of ovarian cancer development

Endometriosis is a fascinating disease that we strive to better understand. Molecular techniques are shedding new light on many important aspects of this disease: from pathogenesis to the recognition of distinct disease variants like deep infiltrating endometriosis. The observation that endometriosis is a cancer precursor has now been strengthened with the knowledge that mutations that are present in endometriosis-associated cancers can be found in adjacent endometriosis lesions. Recent genomic studies, placed in context, suggest that deep infiltrating endometriosis may represent a benign neoplasm that invades locally but rarely metastasises. Further research will help elucidate distinct aberrations which result in this phenotype. With respect to identifying those patients who may be at risk of developing endometriosis-associated cancers, a combination of molecular, pathological, and inheritance markers may define a high-risk group that might benefit from risk-reducing strategies.

Differential regulation of the androgen receptor by protein phosphatase regulatory subunits

The Androgen Receptor (AR) is a key molecule in the development, maintenance and progression of prostate cancer (PC). However, the relationship between the AR and co-regulatory proteins that facilitate AR activity in castrate resistant settings remain understudied. Here we show that protein phosphatase 1 regulatory subunits, identified from a phosphatase RNAi screen, direct PP1 catalytic subunits to a varied yet significant response in AR function. As such, we have characterised the PP1β holoenzyme, myosin phosphatase (MLCP), as a novel ligand independent regulator of the AR. Sustained MLCP activity through down-regulation of the MLCP inhibitory subunit, PPP1R14C, results in impaired AR nuclear translocation, protein stability and transcriptional activity in distinct models of PC progression, culminating in restoration of a non-malignant prostate genotype. Phenotypically, a marked reduction in cell proliferation and migration, characterised by G1 cell cycle arrest is observed, confirming PP1 holoenzyme disruption as a novel treatment approach in PC.

Impact of hormonal modulation at proestrus on ovarian responses and uterine gene expression of suckled anestrous beef cows

Background

This study evaluated the impact of hormonal modulation at the onset of proestrus on ovarian response and uterine gene expression of beef cows.

Methods

A total of 172 anestrous beef cows were assigned to one of four groups according to the treatment with estradiol cypionate (ECP) and/or equine chorionic gonadotropin (eCG) [CON (n = 43), ECP (n = 43), eCG (n = 44) and ECP + eCG (n = 42)].

Results

ECP-treated cows (ECP and ECP + eCG groups) presented greater occurrence of estrus (44.6% vs. 65.4%; P = 0.01) and pregnancy per AI [47.1% vs. 33.3%; P = 0.07], but similar progesterone (P4) concentration at subsequent diestrus than cows not treated with ECP (CON and eCG groups). Nonetheless, eCG-treated cows (eCG and ECP + eCG groups) presented larger follicle at timed AI (12.6 ± 0.3 vs. 13.5 ± 0.3 mm; P = 0.03), greater ovulation rate (96.5% vs. 82.6%; P = 0.008) and greater P4 concentration at d 6 (3.9 ± 0.2 vs. 4.8 ± 0.2 ng/mL; P = 0.001) than cows not treated with eCG (CON and ECP groups). Next, cows with a new corpus luteum 6 d after TAI were submitted to uterine biopsy procedure. Uterine fragments [CON (n = 6), ECP (n = 6)] were analyzed by RNA-Seq and a total of 135 transcripts were differentially expressed between groups (73 genes up-regulated by ECP treatment). Subsequently, uterine samples were analyzed by qPCR (genes associated with cell proliferation). ECP treatment induced greater abundance of PTCH2 (P = 0.07) and COL4A1 (P = 0.02), whereas suppressed EGFR (P = 0.09) expression. Conversely, eCG treatment increased abundance of HB-EGF (P = 0.06), ESR2 (P = 0.09), and ITGB3 (P = 0.05), whereas it reduced transcription of ESR1 (P = 0.05). Collectively, supplementation with ECP or eCG at the onset of proestrous of anestrous beef cows influenced ovarian responses, global and specific endometrial gene expression.

Conclusion

Proestrus estradiol regulate the endometrial transcriptome, particularly stimulating proliferative activity in the endometrium.

Electronic supplementary material

The online version of this article (10.1186/s40104-017-0211-3) contains supplementary material, which is available to authorized users.

Candidate synthetic lethality partners to PARP inhibitors in the treatment of ovarian clear cell cancer

Inhibitors of poly(ADP-ribose) polymerase (PARP) are new types of personalized treatment of relapsed platinum-sensitive ovarian cancer harboring BRCA1/2 mutations. Ovarian clear cell cancer (CCC), a subset of ovarian cancer, often appears as low-stage disease with a higher incidence among Japanese. Advanced CCC is highly aggressive with poor patient outcome. The aim of the present study was to determine the potential synthetic lethality gene pairs for PARP inhibitions in patients with CCC through virtual and biological screenings as well as clinical studies. We conducted a literature review for putative PARP sensitivity genes that are associated with the CCC pathophysiology. Previous studies identified a variety of putative target genes from several pathways associated with DNA damage repair, chromatin remodeling complex, PI3K-AKT-mTOR signaling, Notch signaling, cell cycle checkpoint signaling, BRCA-associated complex and Fanconi's anemia susceptibility genes that could be used as biomarkers or therapeutic targets for PARP inhibition. BRCA1/2, ATM, ATR, BARD1, CCNE1, CHEK1, CKS1B, DNMT1, ERBB2, FGFR2, MRE11A, MYC, NOTCH1 and PTEN were considered as candidate genes for synthetic lethality gene partners for PARP interactions. When considering the biological background underlying PARP inhibition, we hypothesized that PARP inhibitors would be a novel synthetic lethal therapeutic approach for CCC tumors harboring homologous recombination deficiency and activating oncogene mutations. The results showed that the majority of CCC tumors appear to have indicators of DNA repair dysfunction similar to those in BRCA-mutation carriers, suggesting the possible utility of PARP inhibitors in a subset of CCC.

Effect of estrogen receptor β agonists on proliferation and gene expression of ovarian cancer cells

Background

Estrogen receptor (ER) β has been suggested to affect ovarian carcinogenesis. We examined the effects of four ERβ agonists on proliferation and gene expression of two ovarian cancer cell lines.

Methods

OVCAR-3 and OAW-42 ovarian cancer cells were treated with the ERβ agonists ERB-041, WAY200070, Liquiritigenin and 3β-Adiol and cell growth was measured by means of the Cell Titer Blue Assay (Promega). ERβ expression was knocked down by transfection with specific siRNA. Additionally, transcriptome analyses were performed by means of Affymetrix GeneChip arrays. To confirm the results of DNA microarray analysis, Western blot experiments were performed.

Results

All ERβ agonists tested significantly decreased proliferation of OVCAR-3 and OAW-42 cells at a concentration of 10 nM. Maximum antiproliferative effects were induced by flavonoid Liquiritigenin, which inhibited growth of OVCAR-3 cells by 31.2% after 5 days of treatment, and ERB-041 suppressing proliferation of the same cell line by 29.1%. In OAW-42 cells, maximum effects were observed after treatment with the ERβ agonist WAY200070, inhibiting cell growth by 26.8%, whereas ERB-041 decreased proliferation by 24.4%. In turn, knockdown of ERβ with specific siRNA increased cell growth of OAW-42 cells about 1.9-fold. Transcriptome analyses revealed a set of genes regulated by ERβ agonists including ND6, LCN1 and PTCH2, providing possible molecular mechanisms underlying the observed antiproliferative effects.

Conclusion

In conclusion, the observed growth-inhibitory effects of all ERβ agonists on ovarian cancer cell lines in vitro encourage further studies to test their possible use in the clinical setting.

Endometriosis and Ovarian Cancer: an Integrative Review (Endometriosis and Ovarian Cancer)

Despite being initially considered a benign disease, it is widely thought nowadays that endometriosis and especially ovarian endometriomas are neoplastic conditions with the potential to become malignant. This review was conducted to summarize, in a concise and systematic manner, the available scientific data relating endometriosis to ovarian cancer, published in the past five years. After reading abstracts and applying our predefined inclusion and exclusion criteria, a final list of 11 scientific papers was obtained and subjected to review. Endometriosis is associated with an increased risk of developing epithelial ovarian cancer (EOC), mainly of endometrioid and clear cell subtypes. This might be by virtue of the high estrogen concentration with the disease, which leads to malignant proliferation of endometriotic cysts, or be due to mutations in the ARID1A gene and consequent loss of BAF250a expression. The iron produced in the fluid of endometriotic cysts promotes oxidative stress, which in turn may cause genetic mutations and malignant progression of ovarian cysts.

Mesenchymal stem cells: a promising tool for targeted gene therapy of endometriosis

Endometriosis is a leading, benign gynecological disorder around the world. Last few years have witnessed tremendous growth in the field of endometriosis and endometrial stem-cell research. Despite advancements in the biology and pathology of endometriosis, disease recurrence is still an enigma. Gene therapy holds promise in treating many pathologic conditions including endometriosis. Mesenchymal stem cells (MSCs) serve as ideal candidates for regenerative medicine and cell-based therapies. Owing to their specificity to the endometrium, residing endometrial MSC populations could be utilized as ideal candidates for targeting endometrial disorders. Recently, we demonstrated their flexibility for gene transduction using adenoviral vectors. The review highlights the potential of endometrial MSCs in devising targeted gene therapies for endometriosis.

Therapeutic effects of mifepristone combined with Gestrinone on patients with endometriosis

Objective:

To evaluate the clinical therapeutic effects of mifepristone combined with gestrinone on patients with endometriosis.

Methods:

A total of 150 endometriotic patients treated in our hospital between January 2014 and December 2015 were randomly divided into a control group and a treatment group (n=75). The control group began to orally take gestrinone capsules on the second day after menstruation started (2.5 mg/time, twice/week). The treatment group orally took mifepristone tablets (12.5 mg/time, once/day), and the dosage and administration of gestrinone capsules were the same as those of the control group. After 24 weeks of consecutive treatment, the clinical therapeutic effects of the two groups were assessed, and the pelvic symptom score, clinical sign score, serum sex hormone levels and pregnancy outcomes were compared.

Results:

The total effective rates of control and treatment groups were 77.3% and 90.7% respectively, between which the difference was statistically significant (P<0.05). After treatment, the scores of pelvic symptoms (dysmenorrhea, dyspareunia, pelvic pain) and clinical signs (pelvic tenderness, induration) significantly reduced (P<0.05). Each score of the treatment group decreased more significantly than that of the control group did (P<0.05). The serum follicle hormone, luteinizing hormone, estrogen and progesterone levels were significantly lower than those before treatment (P<0.05). Each level of the treatment group dropped more significantly than that of the control group did (P<0.05). The pregnancy rates in the 6th and 12th months of follow-up were 28.0% and 13.3% in the control group respectively, and 42.7% and 29.3% in the treatment group respectively. Such rates of the two groups were significantly different at each follow-up time point (P<0.05).

Conclusion:

Mifepristone combined with gestrinone had satisfactory clinical therapeutic effects on endometriosis by reducing hormone levels and improving pregnancy outcomes. Therefore, this regimen is worthy of promotion and application in clinical practice.

Endometriosis: where are we and where are we going?

Endometriosis currently affects ~5.5 million reproductive-aged women in the U.S. with symptoms such as painful periods (dysmenorrhea), chronic pelvic pain, pain with intercourse (dyspareunia), and infertility. It is defined as the presence of endometrial tissue outside the uterine cavity and is found predominately attached to sites within the peritoneal cavity. Diagnosis for endometriosis is solely made through surgery as no consistent biomarkers for disease diagnosis exist. There is no cure for endometriosis and treatments only target symptoms and not the underlying mechanism(s) of disease. The nature of individual predisposing factors or inherent defects in the endometrium, immune system, and/or peritoneal cavity of women with endometriosis remains unclear. The literature over the last 5 years (2010-2015) has advanced our critical knowledge related to hormones, hormone receptors, immune dysregulation, hormonal treatments, and the transformation of endometriosis to ovarian cancer. In this review, we cover the aforementioned topics with the goal of providing the reader an overview and related references for further study to highlight the progress made in endometriosis research, while concluding with critical areas of endometriosis research that are urgently needed.