Loss of secreted frizzled-related protein 4 correlates with an aggressive phenotype and predicts poor outcome in ovarian cancer patients

New treatment strategies for uterine sarcoma using secreted frizzled‑related proteins

Secreted frizzled-related proteins (SFRPs) are involved in the development of various types of cancer and function by suppressing the Wnt signaling pathway. To elucidate the clinical implications of SFRPs in uterine sarcoma, SFRP expression levels and their effects on uterine leiomyosarcoma cells were examined. Immunostaining for SFRP4 was performed on uterine smooth muscle, uterine fibroid and uterine leiomyosarcoma tissues. Additionally, the effects of SFRP4 administration on cell viability, migration and adhesion were evaluated in uterine leiomyosarcoma SKN cells using the WST-1 assay (Roche Diagnostics) and the CytoSelect™ 24-well Cell Migration Assay Kit and the CytoSelect™ 48-well Cell Adhesion Assay Kit. The expression levels of SFRP4 in uterine leiomyosarcoma tissues were lower than those in normal smooth muscle and uterine fibroid tissues. In addition, SFRP4 suppressed the viability and migration, and increased the adhesion ability of uterine leiomyosarcoma cells compared with in the control group. In conclusion, SFRP4 may suppress the viability and migration, and enhance the adhesion of sarcoma cells. These results suggested that SFRP4 could be considered as a novel therapeutic target for uterine sarcoma.

Short peptide domains of the Wnt inhibitor sFRP4 target ovarian cancer stem cells by neutralizing the Wnt β-catenin pathway, disrupting the interaction between β-catenin and CD24 and suppressing autophagy

AIMS

One of the hallmarks of cancer stem cells (CSC) is hyperactive Wnt β-catenin signaling due to the decreased presence of Wnt antagonists such as secreted frizzled related protein 4 (SFRP4). Cysteine-rich domain (CRD) and netrin-like domain (NLD) are the two functional domains of SFRP4 having anti-tumor properties. In this study, we have explored the effectiveness of short micropeptides SC-301 (from CRD) and SC-401 (from NLD) on CSC properties, EMT, apoptosis and autophagy in ovarian CSCs enriched from PA-1 and SKOV-3 cell lines.

MAIN METHODS

Gene expression analysis, Western blot and immunocytochemistry were performed on ovarian CSCs to evaluate the inhibitory potential of micropeptides to various CSC associated oncogenic properties. Co-immunoprecipitation was performed to detect the binding of CD24 to β-catenin protein complex. CYTO-ID Autophagy Detection Kit 2.0 was used to monitor autophagic flux in peptide treated CSCs.

KEY FINDINGS

It is clearly seen that the micropeptides derived from both the domains inhibit Wnt pathway, initiate apoptosis, inhibit migration and chemosensitize CSCs. Specifically, CD24, a defining marker of ovarian CSC was suppressed by peptide treatment. Notably, interaction between CD24 and β-catenin was disrupted upon peptide treatment. SFRP4 peptide treatment also suppressed the autophagic process which is crucial for CSC survival.

SIGNIFICANCE

The study demonstrated that although both peptides have inhibitory effects, SC-401 was emphatically more effective in targeting CSC properties and down regulating the Wnt β-catenin machinery.

An Overview of Ovarian Cancer: The Role of Cancer Stem Cells in Chemoresistance and a Precision Medicine Approach Targeting the Wnt Pathway with the Antagonist sFRP4

Ovarian cancer is one of the most prevalent gynecological cancers, having a relatively high fatality rate with a low five-year chance of survival when detected in late stages. The early detection, treatment and prevention of metastasis is pertinent and a pressing research priority as many patients are diagnosed only in stage three of ovarian cancer. Despite surgical interventions, targeted immunotherapy and adjuvant chemotherapy, relapses are significantly higher than other cancers, suggesting the dire need to identify the root cause of metastasis and relapse and present more precise therapeutic options. In this review, we first describe types of ovarian cancers, the existing markers and treatment modalities. As ovarian cancer is driven and sustained by an elusive and highly chemoresistant population of cancer stem cells (CSCs), their role and the associated signature markers are exhaustively discussed. Non-invasive diagnostic markers, which can be identified early in the disease using circulating tumor cells (CTCs), are also described. The mechanism of the self-renewal, chemoresistance and metastasis of ovarian CSCs is regulated by the Wnt signaling pathway. Thus, its role in ovarian cancer in promoting stemness and metastasis is delineated. Based on our findings, we propose a novel strategy of Wnt inhibition using a well-known Wnt antagonist, secreted frizzled related protein 4 (sFRP4), wherein short micropeptides derived from the whole protein can be used as powerful inhibitors. The latest approaches to early diagnosis and novel treatment strategies emphasized in this review will help design precision medicine approaches for an effective capture and destruction of highly aggressive ovarian cancer.

Interactome of Paraoxonase PON2 Reveals New Pathways for Tumor Growth Regulation

The interactome of paraoxonase-2 encoded by the PON2 gene was investigated. A cDNA library was screened using a yeast two-hybrid system to search for new proteins interacting with human PON2. Analysis of the identified candidates, along with previously published data on interactors obtained by other methods, indicates the presence of a significant number of indirect interactions between PON2 and EGFR and, consequently, possible regulation of tumor growth with mutant EGFR involving PON2.

SFRP4 Is a Potential Biomarker for the Prognosis and Immunotherapy for Gastric Cancer

Purpose

Secreted frizzled-related protein 4 (SFRP4) is a member of the SFRP family, which functions as either a tumor suppressor or a prooncogenic factor in distinct tumor types. Our research aimed to explore the expression of SFRP4 in gastric cancer, its prognostic significance, and its relationship with immune cell infiltration.

Materials and Methods

Gastric cancer and paracancerous tissue specimens from surgically resected gastric cancer patients were collected to construct tissue microarrays, and immunohistochemistry was used to detect the expression of SFRP4, PD-L1, CD3⁺T, CD4⁺T, and CD8⁺T in these microarrays. The differential expression of SFRP4 and its relationship with the immune microenvironment were evaluated using the TIMER and TISIDB databases. Finally, patient survival was assessed.

Results

SFRP4 expression was elevated in gastric cancer tissues and linked to a poor prognosis (P=0.021). The 5-year survival rate for patients with high SFRP4 expression was only 39.81% but reached 60.02% for patients with low SFRP4 expression. Increased SFRP4 expression correlated with high CD8⁺ T-cell infiltration (P=0.015) and positive PD-L1 expression (P=0.036). High SFRP4 expression was an independent predictor of overall survival (P=0.024 in univariable analysis, P=0.011 in multivariable analysis). Using online databases, we found that SFRP4 expression was higher in gastric cancer tissues and substantially was associated with the immune microenvironment.

Conclusion

SFRP4 is an oncogenic driver that can predict patient survival time in gastric cancer, as well as an important immune-related factor. SFRP4 may be important for guiding immunotherapy in gastric cancer patients.

Diagnostic and prognostic role of TFF3, Romo-1, NF-кB and SFRP4 as biomarkers for endometrial and ovarian cancers: a prospective observational translational study

Purpose

This study aimed to evaluate trefoil factor 3 (TFF3), secreted frizzled-related protein 4 (sFRP4), reactive oxygen species modulator 1 (Romo1) and nuclear factor kappa B (NF-κB) as diagnostic and prognostic markers of endometrial cancer (EC) and ovarian cancer (OC).

Methods

Thirty-one patients with EC and 30 patients with OC undergone surgical treatment were enrolled together with 30 healthy controls in a prospective study. Commercial ELISA kits determined serum TFF-3, Romo-1, NF-кB and sFRP-4 concentrations.

Results

Serum TFF-3, Romo-1 and NF-кB levels were significantly higher in patients with EC and OC than those without cancer. Regarding EC, none of the serum biomarkers differs significantly between endometrial and non-endometrioid endometrial carcinomas. Mean serum TFF-3 and NF-кB levels were significantly higher in advanced stages. Increased serum levels of TFF-3 and NF-кB were found in those with a higher grade of the disease. Regarding OC, none of the serum biomarkers differed significantly among histological subtypes. Significantly increased serum levels of NF-кB were observed in patients with advanced-stage OC than those with stage I and II diseases. No difference in serum biomarker levels was found between those who had a recurrence and those who had not. The sensibility and specificity of these four biomarkers in discriminating EC and OC from the control group showed encouraging values, although no one reached 70%.

Conclusions

TFF-3, Romo-1, NF-кB and SFRP4 could represent new diagnostic and prognostic markers for OC and EC. Further studies are needed to validate our results.

Wnt antagonist as therapeutic targets in ovarian cancer

Ovarian cancer is a fatal malignancy in women with a low survival rate that demands new therapeutic paradigms. Cancer cells acquire various exclusive alterations to proliferate, invade, metastasize, and escape cell death, acting independently of growth-inducing or growth-inhibiting signals. The nature of cellular signaling in tumorigenesis is interwoven. Wnt signaling is an evolutionarily conserved signaling cascade that has been shown to regulate ovarian cancer pathogenesis. The molecular mechanism of Wnt signaling underlying the development of ovarian cancer, drug resistance, and relapse is not completely understood. Extracellularly secreted Wnt signaling inhibitors are crucial regulators of ovarian cancer tumorigenesis and malignant properties of cancer stem cells. Wnt inhibitors arbitrated modifications affecting Wnt pathway proteins on the cell membranes, in the cytoplasm, and in the nucleus have been shown to span essential contributions in the initiation, progression, and chemoresistance of ovarian cancer. Although many extrinsic inhibitors developed targeting the downstream components of the Wnt signaling pathway, investigating the molecular mechanisms of endogenous secreted inhibitors might substantiate prognostic or therapeutic biomarkers development. Given the importance of Wnt signaling in ovarian cancer, more systematic studies combined with clinical studies are requisite to probe the precise mechanistic interactions of Wnt antagonists in ovarian cancer. This review outlines the latest progress on the Wnt antagonists and ovarian cancer-specific regulators such as micro-RNAs, small molecules, and drugs regulating these Wnt antagonists in ovarian tumourigenesis.

KDF1 Promoted Proliferation and Metastasis of Epithelial Ovarian Cancer via Wnt/Beta-Catenin Pathway: TCGA-Based Data Mining and Experimental Validation

Objectives: It has been reported that keratinocyte differentiation factor 1 (KDF1) was related to proliferation, differentiation, and cell cycle. However, the role of KDF1 has not been reported in ovarian cancer. The present study investigated the function and the potential mechanism of KDF1 in ovarian cancer.

Methods: We evaluated the prognostic value in ovarian cancer based on data from the Cancer Genome Atlas (TCGA) database. The Kruskal–Wallis test, Wilcoxon signed-rank test, and logistic regression were used to evaluate the relationship between KDF1 expression and clinicopathologic features. The Cox regression and the Kaplan–Meier method were adopted to evaluate prognosis-related factors. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) gene enrichment analysis, and Gene Set Enrichment Analysis (GSEA) were performed to identify the key biological process related to KDF1. Then the expression of KDF1 in ovarian cancer tissues was validated by streptavidin–peroxidase (SP) immunohistochemistry. The proliferation and invasion ability of KDF1 were determined by EdU and Transwell assay, respectively, with KDF1 gene silencing and overexpression. The mRNA expression of KDF1 was determined by qPCR. The protein expression of KDF1 was determined using the Western blot.

Methods: By performing differential expression analysis on the ovarian cancer data of the TCGA database, it was found that KDF1 is highly expressed in ovarian cancer patients and associated with poorer overall survival (OS) and progression-free survival (PFS) of ovarian cancer patients. The highly expressed KDF1 may reduce cell adhesion according to GO, KEGG, and GSEA results. After analysis combining the relevant clinical features, we found that the high expression of KDF1 is an independent prognostic factor of ovarian cancer and associated with platinum resistance and tumor metastasis in ovarian cancer. At the same time, the BioGRID database showed that there might be protein–protein interaction between KDF1 and E-cadherin. Then we further validated that the high expression of KDF1 had a close correlation with the stage and grade of ovarian cancer in ovarian cancer tissue chips. Silencing KDF1 inhibited the proliferation and invasion ability of SKOV3 cells. By contrast, ectopic expression of KDF1 promoted the proliferation and invasion ability of A2780 cells. We also found that KDF1 can interact with E-cadherin and regulate the expression of Wnt5A and β-catenin, hence activating Wnt/β-catenin pathway via in vitro and vivo experiments.

Conclusions: Based on the bioinformatics analysis, in vitro experiments, and an in vivo study, it is indicated that KDF1 played an important role in ovarian cancer progression and might be a therapeutic target for patients with ovarian cancer.

TRIB2 Stimulates Cancer Stem-Like Properties through Activating the AKT-GSK3β-β-Catenin Signaling Axis

Tribbles homolog 2 (TRIB2) is implicated in tumorigenesis and drug resistance in various types of cancers. However, the role of TRIB2 in the regulation of tumorigenesis and drug resistance of cancer stem cells (CSCs) is still elusive. In the present study, we showed increased expression of TRIB2 in spheroid-forming and aldehyde dehydrogenase-positive CSC populations of A2780 epithelial ovarian cancer cells. Short hairpin RNA-mediated silencing of TRIB2 expression attenuates the spheroid-forming, migratory, tumorigenic, and drug-resistant properties of A2780 cells, whereas overexpression of TRIB2 increases the CSC-like characteristics. TRIB2 overexpression induced GSK3β inactivation by augmenting AKT-dependent phosphorylation of GSK3β at Ser9, followed by increasing β-catenin level via reducing the GSK3β-mediated phosphorylation of β-catenin. Treatment of TRIB2-ovexpressed A2780 cells with the phosphoinositide-3-kinase inhibitor LY294002 abrogated TRIB2-stimulated proliferation, migration, drug resistance of A2780 cells. These results suggest a critical role for TRIB2 in the regulation of CSC-like properties by increasing the stability of β-catenin protein via the AKT-GSK3β-dependent pathways.

The miR-181a-SFRP4 Axis Regulates Wnt Activation to Drive Stemness and Platinum Resistance in Ovarian Cancer

Wnt signaling is a major driver of stemness and chemoresistance in ovarian cancer, yet the genetic drivers that stimulate its expression remain largely unknown. Unlike other cancers, mutations in the Wnt pathway are not reported in high-grade serous ovarian cancer (HGSOC). Hence, a key challenge that must be addressed to develop effective targeted therapies is to identify nonmutational drivers of Wnt activation. Using an miRNA sensor-based approach, we have identified miR-181a as a novel driver of Wnt/β-catenin signaling. miR-181a^high primary HGSOC cells exhibited increased Wnt/β-catenin signaling, which was associated with increased stem-cell frequency and platinum resistance. Consistent with these findings, inhibition of β-catenin decreased stem-like properties in miR-181a^high cell populations and downregulated miR-181a. The Wnt inhibitor SFRP4 was identified as a novel target of miR-181a. Overall, our results demonstrate that miR-181a is a nonmutational activator of Wnt signaling that drives stemness and chemoresistance in HGSOC, suggesting that the miR-181a-SFRP4 axis can be evaluated as a novel biomarker for β-catenin-targeted therapy in this disease. SIGNIFICANCE: These results demonstrate that miR-181a is an activator of Wnt signaling that drives stemness and chemoresistance in HGSOC and may be targeted therapeutically in recurrent disease.

Secreted Frizzled-Related Protein 4 (SFRP4) Is an Independent Prognostic Marker in Prostate Cancers Lacking TMPRSS2: ERG Fusions

Secreted frizzled-related protein 4 (SFRP4) controls WNT signaling and is thought to play a role for tumor aggressiveness. Here, we analyzed a tissue microarray containing 11,152 prostate cancers with pathological, clinical and molecular data by immunohistochemistry. SFRP4 expression was higher in cancer than in non-neoplastic acinar cells. SFRP4 staining was seen in 64.9% of tumors and classified as weak in 33.2%, moderate in 23.9% and strong in 7.8% of cancers. SFRP4 overexpression was linked to advanced tumor stage, high classical/quantitative Gleason grade (p < 0.0001 each), lymph node metastasis (p = 0.0002), and a positive surgical margin (p = 0.0017). SFRP4 positivity was markedly more frequent in ERG positive (77.4%) than in ERG negative cancers (57.4% p < 0.0001). Subset analyses in 2725 cancers with and 3592 cancers without TMPRSS2:ERG fusion revealed that associations with tumor phenotype and patient outcome were largely driven by the subset of ERG negative tumors. In a multivariate analysis including various postoperative and prognostic clinico-pathological features, SFRP4 protein expression emerged as an independent prognostic parameter in ERG negative cancers. SFRP4 immunostaining was significantly linked with 10 of 11 previously analyzed chromosomal deletions (p < 0.05 each). In conclusion, high SFRP4 immunostaining is associated with poor prognosis and genomic instability in ERG negative prostate cancers.

Wnt/β-catenin signalling in ovarian cancer: Insights into its hyperactivation and function in tumorigenesis

Epithelial ovarian cancer (EOC) is the deadliest female malignancy. The Wnt/β-catenin pathway plays critical roles in regulating embryonic development and physiological processes. This pathway is tightly regulated to ensure its proper activity. In the absence of Wnt ligands, β-catenin is degraded by a destruction complex. When the pathway is stimulated by a Wnt ligand, β-catenin dissociates from the destruction complex and translocates into the nucleus where it interacts with TCF/LEF transcription factors to regulate target gene expression. Aberrant activation of this pathway, which leads to the hyperactivity of β-catenin, has been reported in ovarian cancer. Specifically, mutations of CTNNB1, AXIN, or APC, have been observed in the endometrioid and mucinous subtypes of EOC. In addition, upregulation of the ligands, abnormal activation of the receptors or intracellular mediators, disruption of the β-catenin destruction complex, inhibition of the association of β-catenin/E-cadherin on the cell membrane, and aberrant promotion of the β-catenin/TCF transcriptional activity, have all been reported in EOC, especially in the high grade serous subtype. Furthermore, several non-coding RNAs have been shown to regulate EOC development, in part, through the modulation of Wnt/β-catenin signalling. The Wnt/β-catenin pathway has been reported to promote cancer stem cell self-renewal, metastasis, and chemoresistance in all subtypes of EOC. Emerging evidence also suggests that the pathway induces ovarian tumor angiogenesis and immune evasion. Taken together, these studies demonstrate that the Wnt/β-catenin pathway plays critical roles in EOC development and is a strong candidate for the development of targeted therapies.

Wnt Signaling in Ovarian Cancer Stemness, EMT, and Therapy Resistance

Ovarian cancers represent the deadliest among gynecologic malignancies and are characterized by a hierarchical structure with cancer stem cells (CSCs) endowed with self-renewal and the capacity to differentiate. The Wnt/β-catenin signaling pathway, known to regulate stemness in a broad spectrum of stem cell niches including the ovary, is thought to play an important role in ovarian cancer. Importantly, Wnt activity was shown to correlate with grade, epithelial to mesenchymal transition, chemotherapy resistance, and poor prognosis in ovarian cancer. This review will discuss the current knowledge of the role of Wnt signaling in ovarian cancer stemness, epithelial to mesenchymal transition (EMT), and therapy resistance. In addition, the alleged role of exosomes in the paracrine activation of Wnt signaling and pre-metastatic niche formation will be reviewed. Finally, novel potential treatment options based on Wnt inhibition will be highlighted.

Outcome in serous ovarian cancer is not associated with LATS expression

Background

Large tumor suppressor (LATS) proteins are putative tumor suppressors and poorly expressed associated with poor outcome in many cancers. A recent immunohistochemistry study showed that LATS protein expression correlated with poor outcome in serous ovarian cancer.

Materials and methods

We analyzed LATS expression in various ovarian cancer transcriptomic data sets and immunohistochemically assessed LATS protein expression in a Swiss ovarian tumor cohort. Results were compared to clinicopathological characteristics and outcome. We also compared LATS protein expression in serous ovarian cancer cell lines to their EMT status (Western blotting) and drug sensitivity (MTT assay).

Results

The analysis of 15 different transcriptomic data sets showed that LATS2 was associated with poorer outcome, while LATS1 was irrelevant (HR = 1.19 and HR = 1.00, respectively). The TCGA-RNASeqV2 data set showed that low LATS1 and LATS2 were associated with better survival in serous ovarian carcinoma. Despite heterogeneity among the different data sets, LATS expression is not an indicator of survival in serous ovarian cancer and LATS2 expression may even be tumorigenic. LATS expression was neither associated with survival nor with the stage and grade in the Swiss cohort. It was low in cystadenoma, intermediate in carcinoma, and high in borderline tumors and was higher in serous than mucinous ovarian carcinoma. LATS protein expression extent was comparable in epithelial-, intermediate-, and mesenchymal-type ovarian cancer cells and was not associated with drug sensitivity.

Conclusion

These results are largely incompatible with a tumor-suppressive function of LATS in ovarian cancer, and LATS protein level is also not an indicator for drug sensitivity and EMT status of ovarian cancer cells.

CD47 promotes cell growth and motility in epithelial ovarian cancer

Endometriosis is considered a high risk factor for the development of ovarian carcinoma, including clear cell and endometrioid malignancies. The mechanism by which endometriosis-associated ovarian cancer (EAOC) avoids anti-tumor immune surveillance by macrophages remains unclear, but CD47 is a very important immune checkpoint for macrophage phagocytosis. Therefore, we collected 36 clinical ovarian samples and detected the protein profile of CD47 by immunohistochemistry and analyzed the correlation with clinical pathological features using statistical software. We found that CD47 expression was relatively higher in patients with EAOC compared with the normal group. High CD47 expression was positively and significantly correlated with histology (P = 0.007) and tumor grade (P = 0.002). We also found that CD47 overexpression promotes cancer cell growth and motility in the TOV-112D and TOV-21G cell lines. Silencing CD47 and anti-CD47 mAb inhibit cancer cell growth and motility in cancer cell lines. Together, these results demonstrate that CD47 in EAOC may be a useful surface marker and offer a novel therapeutic option by targeting CD47 in ovarian cancer.

A phase 1b dose escalation study of ipafricept (OMP54F28) in combination with paclitaxel and carboplatin in patients with recurrent platinum-sensitive ovarian cancer

OBJECTIVES

The WNT pathway is an important oncologic driver of epithelial ovarian cancer (EOC). The first-in-class recombinant fusion protein ipafricept (IPA) blocks Wnt signaling through binding of Wnt ligands. This phase Ib trial was designed to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RPh2) for IPA in combination with taxane and platinum therapy (C/P).

METHODS

Dose escalation started with a standard 3 + 3 design for IPA/C/P with q3w intravenous IPA on Day 1, in cycles 1 to 6 with C (AUC = 5 mg/ml·min) and P (175 mg/m²). For enhanced bone safety the trial was revised to 6-patient cohorts with a q3w regimen of IPA on Day 1 and C/P on Day 3 (IPA → C/P).

RESULTS

37 patients have been treated; 30 of whom were treated following protocol revision to q3w IPA(D1) → C/P(D3) (2 & 4 mg/kg). IPA-related TEAEs that occurred in ≥15% included: fatigue (40%); nausea (35%); diarrhea and decreased appetite (22%) each; dysgeusia (19%); and vomiting (16.2%). 22% reported ≥1 IPA related TEAE Grade ≥3 the most common of which was neutropenia at 16%. There were no DLTs; the MTD was not reached. The maximum administered dose based on bone safety was 6 mg/kg. The overall response rate (ORR) was 75.7%. Median PFS was 10.3 months (95% CI 8.5-14.2) and OS 33 months (95% CI 23.4-NR).

CONCLUSIONS

IPA is well tolerated in combination with sequential C/P. ORR, PFS and OS are comparable to historical data but bone toxicity at efficacy doses of this particular Wnt inhibitor limit further development in EOC.

Stemness, Pluripotentiality, and Wnt Antagonism: sFRP4, a Wnt antagonist Mediates Pluripotency and Stemness in Glioblastoma

Background: Chemotherapeutic resistance of glioblastoma has been attributed to a self-renewing subpopulation, the glioma stem cells (GSCs), which is known to be maintained by the Wnt β−catenin pathway. Our previous findings demonstrated that exogeneous addition of the Wnt antagonist, secreted fizzled-related protein 4 (sFRP4) hampered stem cell properties in GSCs. Methods: To understand the molecular mechanism of sFRP4, we overexpressed sFRP4 (sFRP4 OE) in three human glioblastoma cell lines U87MG, U138MG, and U373MG. We also performed chromatin immunoprecipitation (ChIP) sequencing of sFRP4 OE and RNA sequencing of sFRP4 OE and sFRP4 knocked down U87 cells. Results: We observed nuclear localization of sFRP4, suggesting an unknown nuclear role. ChIP-sequencing of sFRP4 pulldown DNA revealed a homeobox Cphx1, related to the senescence regulator ETS proto-oncogene 2 (ETS2). Furthermore, miRNA885, a p53-mediated apoptosis inducer, was upregulated in sFRP4 OE cells. RNA sequencing analysis suggested that sFRP4-mediated apoptosis is via the Fas-p53 pathway by activating the Wnt calcium and reactive oxygen species pathways. Interestingly, sFRP4 OE cells had decreased stemness, but when knocked down in multipotent mesenchymal stem cells, pluripotentiality was induced and the Wnt β-catenin pathway was upregulated. Conclusions: This study unveils a novel nuclear role for sFRP4 to promote apoptosis by a possible activation of DNA damage machinery in glioblastoma.

Aberrant expression of the sFRP and WIF1 genes in invasive non-functioning pituitary adenomas

Non-functioning pituitary adenomas (NFPAs) are the most common pituitary tumors and mainly invade the sphenoid, cavernous sinus or dura mate. Aberrant regulation of the Wnt signaling pathway plays an important role in tumorigenesis. This study was designed to investigate the relationships between secreted frizzled-related proteins (sFRPs), WIF1 genes and the invasion of NFPAs by tissue microassays (TMAs) of samples from 163 patients. Significantly weaker staining of WIF1 and sFRP4 were detected in the invasive group compared with the non-invasive group by TMAs (p = 0.002, p < 0.001). Univariate analysis showed a significant correlation between tumor invasion and low expression of WIF1 and sFRP4 (p = 0.002, p < 0.001). A similar trend was observed when analyzing the mRNA and protein levels through RT-PCR and western blot experiments. Methylation of the WIF1 promoter was significantly increased in invasive NFPAs compared with the noninvasive group (p = 0.004). The average progression free survival time in the high WIF1 group was longer than that in the low WIF1 group (p = 0.025). Furthermore, RT-PCR measured the levels of 11 miRNAs targeting WIF1 according to the Targetscan database and PubMed. The levels of miRNA-137, miRNA-374a-5p and miRNA-374b-5p in the invasive group were 0.037-fold, 0.577-fold and 0.44-fold that of the noninvasive group (p = 0.003, p = 0.049 and p = 0.047). Overexpression of miRNA-137 could inhibit the proliferation and invasion of GH3 cells through cell viability and Transwell experiments (p < 0.05). Furthermore, the WIF1 level was upregulated after overexpression of miRNA-137 compared with miRNA-137-NC (control miRNA) in GH3 cells. Our data suggest that WIF1 may be potential biomarker for the aggressiveness of NFPAs. miRNA-137 plays an important role in the Wnt signaling pathway by affecting promoter methylation of WIF1.

Increased secreted frizzled-related protein 4 and ficolin-3 levels in gestational diabetes mellitus women

By biochemical and epidemiological similarity with type 2 diabetes mellitus (T2DM), gestational diabetes mellitus (GDM) has some overlap between prediction markers and risk factors of T2DM. The present study aimed to establish that secreted frizzled-related protein 4 (SFRP4) and ficolin-3 levels, which have been linked to insulin resistance and the development of T2DM, are elevated in GDM women. A longitudinal prospective cohort study of 86 GDM and 273 normal glucose tolerant (NGT) pregnant women was performed. The clinical parameters, lipid profiles, and serum SFRP4 and ficolin-3 levels were tested during the early and late second-trimester and third-trimester of pregnancy. Both SFRP4 and ficolin-3 levels were significantly higher in GDM women as compared to the NGT participants at three test points (p < 0.01). Spearman's correlation analysis showed that serum SFRP4 levels were significantly positively correlated with ficolin-3 during the early and late second-trimester and third-trimester of pregnancy. The elevated SFRP4 and ficolin-3 concentrations at 16-18 weeks gestation significantly associated with GDM were conformed using binary logistic regression analysis after controlling for other variables [odds ratios (OR) with 95% confidence intervals (CI) for SFRP4: 2.84 (1.78-4.53), p < 0.01; for ficolin-3: 2.45 (1.55-3.88), p < 0.01]. In Conclusions, increased SFRP4 and ficolin-3 levels are significantly associated with GDM development and might be important risk factors for this pregnancy complication.

Secreted frizzled related protein 4 (sFRP4) update: A brief review

Secreted frizzled-related proteins control a multitude of biological phenomena throughout development and adult life in humans. In parallel, aberrant gene expression and abnormal secreted protein levels accompany a wide range of pathologies in humans. In this review, we provide a brief introduction to sFRP4, an update of the pathways it's involved, its various physiological actions that are reported to contribute to diseases, outlining the importance of its wider research and specific modulation by pharmacologic interventions. First recognized as a novel molecule that co-purified with a disparate protein, its identity was based on its sequence homology to the frizzled receptors. Once multiple members of the family were cloned, their genetic loci, tissue and subcellular distributions were located. Nucleotide and amino acid sequences were characterized and homology to different organisms was found to be present that helped elucidate their actions. Following subsequent experimental studies, they were found to be secreted proteins with an affinity to bind to the Wnt ligands, participating in different developmental and adult homeostatic pathways by the virtue of their regulatory function to the Wnt signal transduction system. Secreted frizzled related protein 4 has garnered considerable attention in the recent years following breakthrough discoveries implicating them in the pathogenesis of various diseases. Studies investigating them can provide information not only regarding their association with a disease but can also help use them as potential biomarkers and therapeutic targets.

Potential signaling pathways as therapeutic targets for overcoming chemoresistance in mucinous ovarian cancer

Cases of mucinous ovarian cancer are predominantly resistant to chemotherapies. The present review summarizes current knowledge of the therapeutic potential of targeting the Wingless (WNT) pathway, with particular emphasis on preclinical and clinical studies, for improving the chemoresistance and treatment of mucinous ovarian cancer. A review was conducted of English language literature published between January 2000 and October 2017 that concerned potential signaling pathways associated with the chemoresistance of mucinous ovarian cancer. The literature indicated that aberrant activation of growth factor and WNT signaling pathways is specifically observed in mucinous ovarian cancer. An evolutionarily conserved signaling cascade system including epidermal growth factor/RAS/RAF/mitogen-activated protein kinase kinase/extracellular signal-regulated protein kinase, phosphoinositide 3-kinase/Akt and WNT signaling regulates a variety of cellular functions; their crosstalk mutually enhances signaling activity and induces chemoresistance. Novel antagonists, modulators and inhibitors have been developed for targeting the components of the WNT signaling pathway, namely Frizzled, low-density lipoprotein receptor-related protein 5/6, Dishevelled, casein kinase 1, AXIN, glycogen synthase kinase 3β and β-catenin. Targeted inhibition of WNT signaling represents a rational and promising novel approach to overcome chemoresistance, and several WNT inhibitors are being evaluated in preclinical studies. In conclusion, the WNT receptors and their downstream components may serve as novel therapeutic targets for overcoming chemoresistance in mucinous ovarian cancer.

Human epicardial adipose tissue-derived and circulating secreted frizzled-related protein 4 (SFRP4) levels are increased in patients with coronary artery disease

Background

Previous studies have demonstrated that secreted frizzled-related protein 4 (SFRP4) is associated with impaired glucose and triglyceride metabolism in patients with stable coronary artery disease. In the present study, we investigated human epicardial adipose tissue (EAT)-derived and circulating SFRP4 levels in patients with coronary artery disease (CAD).

Methods

Plasma samples and adipose biopsies from EAT and subcutaneous adipose tissue (SAT) were collected from patients with CAD (n = 40) and without CAD (non-CAD, n = 30) during elective cardiac surgery. The presence of CAD was identified by coronary angiography. SFRP4 mRNA and protein expression levels in adipose tissue were detected by quantitative real-time PCR and immunohistochemistry, respectively. Plasma SFRP4 concentrations were measured by an enzyme-linked immunosorbent assay (ELISA). Correlation analysis and multivariate linear regression analysis were used to determine the association of SFRP4 expression with atherosclerosis as well as clinical risk factors.

Results

SFRP4 mRNA and protein expression levels were significantly lower in EAT than in paired SAT in patients with and without CAD (all P < 0.05). Compared to non-CAD patients, CAD patients had higher SFRP4 expression levels in EAT (both mRNA and protein levels) and in plasma. Multivariate linear regression analysis showed that CAD was an independent predictor of SFRP4 expression levels in EAT (beta = 0.442, 95% CI 0.030–0.814; P = 0.036) and in plasma (beta = 0.300, 95% CI 0.056–0.545; P = 0.017). SAT-derived SFRP4 mRNA levels were independently associated with fasting insulin levels (beta = 0.382, 95% CI 0.008–0.756; P = 0.045). In addition, plasma SFRP4 levels were positively correlated with BMI (r = 0.259, P = 0.030), fasting insulin levels (r = 0.306, P = 0.010) and homeostasis model assessment of insulin resistance (HOMA-IR) values (r = 0.331, P = 0.005).

Conclusions

EAT-derived and circulating SFRP4 expression levels were increased in patients with CAD. EAT SFRP4 mRNA levels and plasma SFRP4 concentrations were independently associated with the presence of CAD.

TET1 inhibits EMT of ovarian cancer cells through activating Wnt/β-catenin signaling inhibitors DKK1 and SFRP2

OBJECTIVE

Epithelial ovarian cancer (EOC) is the deadliest type of ovarian cancer, but the mechanisms contributing to its tumorigenesis are not well understood. Herein, we will elucidate the role of Ten-eleven translocation 1 (TET1) in EOC development.

METHODS

The expression of TET1 in EOC cell lines and primary samples was examined by western blot and immunohistochemistry. The biological role of ectopic TET1 overexpression was revealed by a series of in vitro functional studies. Its downstream signaling pathway was predicted by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of microarray data. The methylation level and expression of Wnt/β-catenin signaling inhibitors Dikkopf 1 (DKK1) and secreted Fzd receptor protein 2 (SFRP2) were examined by Chromatin immunoprecipitation (ChIP) assay, Epimark™ 5hmC and 5mC level analysis and quantitative RT-PCR. Small interference RNA (siRNA) technology was used to investigate the biological roles of DKK1 and SFRP2.

RESULTS

TET1 expression was inversely correlated with clinical stage in patients with EOC by tissue microarray (TMA). TET1 expression was undetected in 6 types of EOC cell lines. Ectopic expression of TET1 inhibited colony formation, cell migration and invasion in SKOV3 and OVCAR3 cells. Furthermore, TET1 overexpression reversed the epithelial-mesenchymal transition (EMT) process of SKOV3 cells. Mechanistically, TET1 potently inhibited canonical Wnt/β-catenin signaling by demethylating and upregulating two upstream antagonists of this pathway, SFRP2 and DKK1, which was associated with inhibition of EMT and cancer cell metastasis.

CONCLUSION

This study uncovers that TET1 has potent tumor-suppressive effects in EOC by activating Wnt/β-catenin signaling inhibitors DKK1 and SFRP2.

sFRP4 signalling of apoptosis and angiostasis uses nitric oxide-cGMP-permeability axis of endothelium

Nitric oxide (NO) plays a critical role in endothelial functions such as cellular migration, vascular permeability and angiogenesis. Angiogenesis, the formation of new blood vessels from "pre-existing" ones is a carefully regulated process and essential during reproduction, development and wound healing. Previously our lab group reported that Secreted Frizzled-Related Protein 4 (sFRP4) could inhibit angiogenesis in both in vitro and in vivo conditions. sFRP4 belongs to a family of secreted glycoproteins that function as antagonists of the canonical Wnt signalling pathway. Although the pro-apoptotic role of sFRP4 is well discussed in literature, little is known in regards to its anti-angiogenic property. The objective of this study was to elucidate sFRP4 implications in NO biology of the endothelium. Results demonstrate that sFRP4 causes endothelial dysfunction by suppressing NO-cGMP signaling and elevating corresponding ROS levels. The imbalance between NO and ROS levels results in apoptosis and subsequent leakiness of endothelium as confirmed in vivo (Texas red/Annxin - CAM assay) and in vitro (Monolayer permeability assay) conditions. Furthermore utilizing peptides synthesized from the CRD domain of sFRP4, our results showed that while these peptides were able to cause endothelial dysfunctions, they did not cause apoptosis of the endothelial cells. Thereby confirming that sFRP4 can mediate its anti-angiogenic effect independent of its pro-apoptotic property. In conclusion, the current study reports that sFRP4-mediated anti-angiogenesis occurs as a result of impaired NO-cGMP signaling which in turn allow for elevation of redox levels and promotion of apoptosis of endothelial cells.

Targeting the ROR1 and ROR2 receptors in epithelial ovarian cancer inhibits cell migration and invasion

AIM

In recent years, the Wnt signalling pathway has been implicated in epithelial ovarian cancer and its members have potential as diagnostic, prognostic and therapeutic targets. Here we investigated the role of two Wnt receptor tyrosine kinases (RTKs), ROR1 and ROR2, and their putative ligand, Wnt5a, in ovarian cancer.

METHODS

Immunohistochemistry for ROR2 was performed in a large patient cohort, including benign controls, borderline tumours and epithelial ovarian cancer. In addition, siRNA was used to silence ROR1, ROR2 and Wnt5a individually, and together, in two ovarian cancer cell lines, and the effects on cell proliferation, adhesion, migration and invasion were measured.

RESULTS

ROR2 expression is significantly increased in ovarian cancer patients compared to patients with benign disease. In vitro assays showed that silencing either receptor inhibits ovarian cancer cell migration and invasion, and concurrently silencing both receptors has an even stronger inhibitory effect on proliferation, migration and invasion.

CONCLUSIONS

ROR2 expression is increased in epithelial ovarian cancer, and silencing ROR2 and its sister receptor ROR1 has a strong inhibitory effect on the ability of ovarian cancer cells to proliferate, migrate and invade through an extracellular matrix.

Antagonizing canonical Wnt signaling pathway by recombinant human sFRP4 purified from E. coli and its implications in cancer therapy

The Wnt signaling pathway plays a predominant role in aberrant proliferation in myriad of cancers. In non-cancerous cells, Wnts are blocked by the secreted frizzled-related proteins (sFRPs) that are generally downregulated in cancer cells. We have purified and characterized bacterially expressed glutathione S-transferase-tagged SFRP4 from a novel clone generated from human cell origin. Cervical cancer (HeLa) and lung cancer (A549) cells, in which Wnt and associated genes were found to be expressed, were treated with the purified recombinant sFRP4, which revealed a significant dose-dependent cell growth inhibition up to 40 %. The current investigation on functionality of this bacterially produced recombinant sFRP4 in arresting cancer cell proliferation is the first of its kind, where G2/M phase arrest and early apoptosis were evident. Increase in phosphorylated β-catenin in sFRP4 treatment indicated inhibition of Wnt pathway, which was further confirmed by downregulation of pro-proliferative genes, namely cyclin D1, c-myc, and survivin. Functional activity of recombinant sFRP4 was further exploited in co-therapy module with chemotherapeutic drugs to decipher molecular events. Collectively, our study on purified recombinant sFRP4 from bacterial host holds great promise in targeting Wnt signaling for exploring new strategies to combat cancer.

Expression profiling of prostate cancer tissue delineates genes associated with recurrence after prostatectomy

Prostate cancer is a leading cause of cancer death amongst males. The main clinical dilemma in treating prostate cancer is the high number of indolent cases that confer a significant risk of overtreatment. In this study, we have performed gene expression profiling of tumor tissue specimens from 36 patients with prostate cancer to identify transcripts that delineate aggressive and indolent cancer. Key genes were validated using previously published data and by tissue microarray analysis. Two molecular subgroups were identified with a significant overrepresentation of tumors from patients with biochemical recurrence in one of the groups. We successfully validated key transcripts association with recurrence using two publically available datasets totaling 669 patients. Twelve genes were found to be independent predictors of recurrence in multivariate logistical regression analysis. SFRP4 gene expression was consistently up regulated in patients with recurrence in all three datasets. Using an independent cohort of 536 prostate cancer patients we showed SFRP4 expression to be an independent predictor of recurrence after prostatectomy (HR = 1.35; p = 0.009). We identified SFRP4 to be associated with disease recurrence. Prospective studies are needed in order to assess the clinical usefulness of the identified key markers in this study.

Elevated β-catenin activity contributes to carboplatin resistance in A2780cp ovarian cancer cells

Ovarian cancer is the fifth leading cause of cancer-related mortalities in women. Epithelial ovarian cancer (EOC) represents approximately 90% of all ovarian malignancies. Most EOC patients are diagnosed at advanced stages and current chemotherapy regimens are ineffective against advanced EOC due to the development of chemoresistance. It is important to better understand the molecular mechanisms underlying acquired resistance to effectively manage this disease. In this study, we examined the expression of the Wnt/β-catenin signaling components in the paired cisplatin-sensitive (A2780s) and cisplatin-resistant (A2780cp) EOC cell lines. Our results showed that several negative regulators of Wnt signaling are downregulated, whereas a few Wnt ligands and known Wnt/β-catenin target genes are upregulated in A2780cp cells compared to A2780s cells, suggesting that Wnt/β-catenin signaling is more active in A2780cp cells. Further analysis revealed nuclear localization of β-catenin and higher β-catenin transcriptional activity in A2780cp cells compared to A2780s cells. Finally, we demonstrated that chemical inhibition of β-catenin transcriptional activity by its inhibitor CCT036477 sensitized A2780cp cells to carboplatin, supporting a role for β-catenin in carboplatin resistance in A2780cp cells. In conclusion, our data suggest that increased Wnt/β-catenin signaling activity contributes to carboplatin resistance in A2780cp cells.

Wnt signalling in gynaecological cancers: A future target for personalised medicine?

The three major gynaecological cancers, ovarian, uterine and cervical, contribute a significant burden to global cancer mortality, and affect women in both developed and developing countries. However, unlike other cancer types that have seen rapid advances and incorporation of targeted treatments in recent years, personalised medicine is not yet a reality in the treatment of gynaecological cancers. Advances in sequencing technology and international collaborations and initiatives such as The Cancer Genome Atlas are now revealing the molecular basis of these cancers, and highlighting key signalling pathways involved. One pathway which plays a role in all three cancer types, is the Wnt signalling pathway. This complex developmental pathway is altered in most human malignancies, and members of this pathway, particularly the recently linked ROR receptor tyrosine kinases may be attractive future therapeutic targets. This review provides an up-to-date summary of research into Wnt signalling and ovarian, uterine and cervical cancers, and discusses the potential of the Wnt pathway as a future target for personalised medicine in gynaecological cancers.

Low expression of secreted frizzled-related protein 4 in aggressive pituitary adenoma

OBJECTIVE

The secreted frizzled-related proteins (sFRPs) are reported to be antagonists of a number of tumors. This study was designed to investigate the relationship of sFRP4 with aggressiveness of pituitary adenomas.

MATERIAL AND METHOD

Specimens were classified into three groups: normal control (n = 10), non-aggressive group (n = 42) and aggressive group (n = 26) according to preoperative magnetic resonance imaging (MRI)/computed tomography. sFRP4 were investigated by PCR, Western blotting, and immunohistochemistry (IHC). The methylation status of the sFRP4 promoter region was observed by MassArray. Cell culture and 5-aza-2-deoxycytidine treatment was performed to observe the relationship of downregulation of sFRP4 with methylation of the sFRP4 gene.

RESULTS

PCR and Western blot results showed that sFRP4 expression was downregulated in aggressive pituitary adenomas, which was confirmed by IHC. Methylation of the sFRP4 promoter was increased in aggressive pituitary adenomas. And methylation of the sFRP4 promoter lead to downregulation of sFRP4 expression.

CONCLUSIONS

sFRP4 expression is inversely related to the aggressiveness of pituitary adenomas, and act as a tumor suppressor.

Signaling Circuits and Regulation of Immune Suppression by Ovarian Tumor-Associated Macrophages

The barriers presented by immune suppression in the ovarian tumor microenvironment present one of the biggest challenges to development of successful tumor vaccine strategies for prevention of disease recurrence and progression following primary surgery and chemotherapy. New insights gained over the last decade have revealed multiple mechanisms of immune regulation, with ovarian tumor-associated macrophages/DC likely to fulfill a central role in creating a highly immunosuppressive milieu that supports disease progression and blocks anti-tumor immunity. This review provides an appraisal of some of the key signaling pathways that may contribute to immune suppression in ovarian cancer, with a particular focus on the potential involvement of the c-KIT/PI3K/AKT, wnt/β-catenin, IL-6/STAT3 and AhR signaling pathways in regulation of indoleamine 2,3-dioxygenase expression in tumor-associated macrophages. Knowledge of intercellular and intracellular circuits that shape immune suppression may afford insights for development of adjuvant treatments that alleviate immunosuppression in the tumor microenvironment and enhance the clinical efficacy of ovarian tumor vaccines.

Methylation of SFRPs and APC genes in ovarian cancer infected with high risk human papillomavirus

BACKGROUND

Secreted frizzled-related protein (SFRP) genes, new tumor suppressor genes, are negative regulators of the Wnt pathway whose alteration is associated with various tumors. In ovarian cancer, SFRPs genes promoter methylation can lead to gene inactivation. This study investigated mechanisms of SFRP and adenomatous polyposis coli (APC) genes silencing in ovarian cancer infected with high risk human papillomavirus.

MATERIALS AND METHODS

DNA was extracted from 200 formalin-fixed paraffin-embedded ovarian cancer and their normal adjacent tissues (NAT) and DNA methylation was detected by methylation specific PCR (MSP). High risk human papillomavirus (HPV) was detected by nested PCR with consensus primers to amplify a broad spectrum of HPV genotypes.

RESULTS

The percentages of SFRP and APC genes with methylation were significantly higher in ovarian cancer tissues infected with high risk HPV compared to NAT. The methylated studied genes were associated with suppression in their gene expression.

CONCLUSION

This finding highlights the possible role of the high risk HPV virus in ovarian carcinogenesis or in facilitating cancer progression by suppression of SFRP and APC genes via DNA methylation.

Association of secreted frizzled-related protein 4 (SFRP4) with type 2 diabetes in patients with stable coronary artery disease

Background

Secreted frizzled-related proteins (SFRP) are regulators of Wnt-signalling. SFRP4 has been shown to regulate insulin exocytosis and is overexpressed in type 2 diabetes mellitus.

Here we characterized the relation of SFRP4 to glucose and triglyceride metabolism and outcomes in patients with stable coronary artery disease on statin treatment in the prospective Homburg Cream & Sugar Study (NCT00628524).

Methods

Fasting SFRP4 concentrations were measured by ELISA in 504 consecutive patients with stable CAD confirmed by angiography.

Results

The median age was 68 years and 83% of patients were male. Oral glucose tolerance tests were performed in all patients without known diabetes for metabolic characterization. 24.4% of patients showed normal glucose tolerance, 29.4% impaired glucose tolerance and 46.2% diabetes mellitus. SFRP4 concentrations correlated with insulin (R = 0.153, p = 0.001), HbA1c (R = 0.166, p < 0.0001), fasting triglycerides (R = 0.113, p = 0.011) and higher triglycerides after lipid challenge (postprandial triglycerides R = 0.124, p = 0.005; AUC R = 0.134, p = 0.003). Higher SFRP4 concentrations were associated with type 2 diabetes, metabolic syndrome, and severity of diabetes.

The primary outcome was the composite of cardiovascular death and cardiovascular hospitalization within 48 months follow-up. Comparison of event-free survival between SFRP4 tertiles showed that SFRP4 concentrations were not predictive for cardiovascular outcome.

Conclusions

SFRP4 concentrations are associated with impaired glucose and triglyceride metabolism but do not predict cardiovascular outcome in patients with stable coronary artery disease on treatment.

Activation of the Wnt pathway through Wnt2 promotes metastasis in pancreatic cancer

Wnt signaling pathway plays an important role in physiological and pathological process, including in the occurrence and development of tumor. The purpose of this study is to determine whether Wnt2 and sFRP4, key molecules of signaling pathway, are of prognostic value for survival in patients with pancreatic cancer. We performed immunohistochemistry on tissue microarrays containing 90 pancreatic cancer specimens to evaluate the protein expression of Wnt2 and sFRP4. Our results showed that the cytoplasmic expression level of Wnt2 in pancreatic cancer tissues was significantly associated with LNM (P=0.029) and AJCC stage (P=0.008). Additionally, Kaplan-Meier analysis indicated that high Wnt2 expression was significantly correlated with poor clinical outcomes of patients with pancreatic cancer. In conclusion, Wnt2 may play an important role in the development of pancreatic cancer through activation of the Wnt pathways and serve as a potential candidate for treatment target of pancreatic cancer.

mRNA-based vaccines synergize with radiation therapy to eradicate established tumors

BACKGROUND

The eradication of large, established tumors by active immunotherapy is a major challenge because of the numerous cancer evasion mechanisms that exist. This study aimed to establish a novel combination therapy consisting of messenger RNA (mRNA)-based cancer vaccines and radiation, which would facilitate the effective treatment of established tumors with aggressive growth kinetics.

METHODS

The combination of a tumor-specific mRNA-based vaccination with radiation was tested in two syngeneic tumor models, a highly immunogenic E.G7-OVA and a low immunogenic Lewis lung cancer (LLC). The molecular mechanism induced by the combination therapy was evaluated via gene expression arrays as well as flow cytometry analyses of tumor infiltrating cells.

RESULTS

In both tumor models we demonstrated that a combination of mRNA-based immunotherapy with radiation results in a strong synergistic anti-tumor effect. This was manifested as either complete tumor eradication or delay in tumor growth. Gene expression analysis of mouse tumors revealed a variety of substantial changes at the tumor site following radiation. Genes associated with antigen presentation, infiltration of immune cells, adhesion, and activation of the innate immune system were upregulated. A combination of radiation and immunotherapy induced significant downregulation of tumor associated factors and upregulation of tumor suppressors. Moreover, combination therapy significantly increased CD4+, CD8+ and NKT cell infiltration of mouse tumors.

CONCLUSION

Our data provide a scientific rationale for combining immunotherapy with radiation and provide a basis for the development of more potent anti-cancer therapies.

The non-canonical Wnt ligand, Wnt5a, is upregulated and associated with epithelial to mesenchymal transition in epithelial ovarian cancer

OBJECTIVE

Aberrant Wnt signalling has previously been associated with gynaecological cancers, and the aim of this study was to investigate the expression of Wnt5a in epithelial ovarian cancer, and clarify its role in activating or inhibiting β-catenin dependent and independent Wnt signalling pathways.

METHOD

Wnt5a expression was investigated in a large cohort of epithelial ovarian cancer patient samples using immunohistochemistry and correlated with clinicopathological variables. Wnt5a function was investigated in vitro in ovarian cell lines.

RESULTS

Wnt5a expression was found to be upregulated in all major subtypes (serous, endometrioid, clear cell and mucinous) of epithelial ovarian cancer compared to borderline tumours and benign controls. Treatment of ovarian surface epithelial cells with recombinant Wnt5a decreased cell adhesion and was associated with increased epithelial to mesenchymal transition (EMT). In addition, downstream targets of β-catenin dependent Wnt signalling were inhibited, and β-catenin independent targets increased following Wnt5a upregulation. Knockdown of Wnt5a in ovarian cancer cells was associated with a mesenchymal to epithelial transition (MET), but had no significant effect on cell migration or proliferation.

CONCLUSION

This study adds to the increasing evidence that Wnt signalling may play an important role in ovarian cancer development. Utilising an unparalleled large cohort of 623 patients, Wnt5a protein expression was shown to be significantly higher in ovarian cancer patients when compared to benign and borderline ovarian tumours and healthy control patients. In addition, we have utilised in vitro models to show for the first time in ovarian cancer that Wnt5a driven non-canonical pathways can alter epithelial to mesenchymal transition (EMT).

Reversible infertility in a liver receptor homologue-1 (LRH-1)-knockdown mouse model

Liver receptor homologue-1 (LRH-1) is an orphan nuclear receptor that has been implicated in steroid hormone biosynthesis and fertility. Herein we describe a transgenic inducible short hairpin (sh) RNA mouse model that was used to study the effect of transient LRH-1 knockdown in vivo. Induction of expression of the shRNA directed against LRH-1 for 2–6 weeks resulted in 80% knockdown of LRH-1 protein in the ovary and complete infertility. Gonadotropin hyperstimulation could not rescue the observed defects in ovulation and corpus luteum formation in LRH-1-knockdown mice. The infertility phenotype was fully reversible because LRH-1-knockdown females became pregnant and delivered normal size litters and healthy pups after cessation of LRH-1 shRNA expression. Timed ovarian microarray analysis showed that, in line with the observed decrease in plasma progesterone levels, key steroid biosynthesis genes, namely Star, Cyp11a1, Hsd3b and Scarb1, were downregulated in LRH-1-knockdown ovaries. In contrast with what has been described previously, no clear effect was observed on oestrogenic activity in LRH-1-knockdown mice. Only Sult1e1 and, surprisingly, Hsd17b7 expression was modulated with potentially opposite effects on oestradiol bioavailability. In conclusion, the fully reversible infertility phenotype of LRH-1-knockdown mice shows the feasibility of an LRH-1 antagonist as new contraceptive therapy with a mechanism of action that most prominently affects cholesterol availability and progesterone production.

Secreted frizzled related proteins: Implications in cancers

The Wnt (wingless-type) signaling pathway plays an important role in embryonic development, tissue homeostasis, and tumor progression becaluse of its effect on cell proliferation, migration, and differentiation. Secreted frizzled-related proteins (SFRPs) are extracellular inhibitors of Wnt signaling that act by binding directly to Wnt ligands or to Frizzled receptors. In recent years, aberrant expression of SFRPs has been reported to be associated with numerous cancers. As gene expression of SFRP members is often lost through promoter hypermethylation, inhibition of methylation through the use of epigenetic modifying agents could renew the expression of SFRP members and further antagonize deleterious Wnt signaling. Several reports have described epigenetic silencing of these Wnt signaling antagonists in various human cancers, suggesting their possible role as tumor suppressors. SFRP family members thus come across as potential tools in combating Wnt-driven tumorigenesis. However, little is known about SFRP family members and their role in different cancers. This review comprehensively covers all the available information on the role of SFRP molecules in various human cancers.

The Wnt/β-catenin pathway in ovarian cancer: a review

OBJECTIVE

Ovarian cancer is the deadliest gynecologic malignancy and the fifth leading cause of death from cancer in women in the U.S. Since overall survival remains poor, there is a need for new therapeutic paradigms. This paper will review the Wnt/β-catenin pathway as it relates to epithelial ovarian cancer, specifically its role in chemoresistance and its potential role as a target for chemosensitization.

METHODS

A PubMed search was performed for articles published pertaining to Wnt/β-catenin pathway specific to ovarian cancer. Wnt/β-catenin signaling pathways play an active role in cancer stem cells (CSCs) and carcinogenesis of all ovarian cancer subtypes. Studies also have shown that ovarian CSCs are involved in chemoresistance, metastasis, and tumor recurrence.

RESULTS

Wnt/β-catenin target genes regulate cell proliferation and apoptosis, thereby mediating cancer initiation and progression. The Wnt/β-catenin pathway is one of the major signaling pathways thought to be involved in epithelial-to-mesenchymal transition (EMT). Alterations affecting Wnt pathway proteins on the cell membrane, in the cytoplasm, and in the nucleus have been shown to play important roles in the tumorigenesis of ovarian cancer.

CONCLUSIONS

Wnt signaling is activated in epithelial ovarian cancer. Given the role of the Wnt/β-catenin pathway in carcinogenesis, more pre-clinical studies are warranted to further investigate other Wnt inhibitors in ovarian cancer. The Wnt pathway should also be investigated as a potential target in the development of new drugs for ovarian cancer as a single agent and in combination with chemotherapy or other targeted agents.

Mesenchymal stem/progenitors and other endometrial cell types from women with polycystic ovary syndrome (PCOS) display inflammatory and oncogenic potential

CONTEXT

Endometrium in polycystic ovary syndrome (PCOS) presents altered gene expression indicating progesterone resistance and predisposing to reduced endometrial receptivity and endometrial cancer.

OBJECTIVE

We hypothesized that an altered endocrine/metabolic environment in PCOS may result in an endometrial "disease phenotype" affecting the gene expression of different endometrial cell populations, including stem cells and their differentiated progeny.

DESIGN AND SETTING

This was a prospective study conducted at an academic medical center.

PATIENTS AND MAIN OUTCOME MEASURES

Proliferative-phase endometrium was obtained from 6 overweight/obese PCOS (National Institutes of Health criteria) and 6 overweight/obese controls. Microarray analysis was performed on fluorescence-activated cell sorting-isolated endometrial epithelial cells (eEPs), endothelial cells, stromal fibroblasts (eSFs), and mesenchymal stem cells (eMSCs). Gene expression data were validated using microfluidic quantitative RT-PCR and immunohistochemistry.

RESULTS

The comparison between eEP(PCOS) and eEP(Ctrl) showed dysregulation of inflammatory genes and genes with oncogenic potential (CCL2, IL-6, ORM1, TNAIFP6, SFRP4, SPARC). eSF(PCOS) and eSF(Ctrl) showed up-regulation of inflammatory genes (C4A/B, CCL2, ICAM1, TNFAIP3). Similarly, in eMSC(PCOS) vs eMSC(Ctrl), the most up-regulated genes were related to inflammation and cancer (IL-8, ICAM1, SPRR3, LCN2). Immunohistochemistry scoring showed increased expression of CCL2 in eEP(PCOS) and eSF(PCOS) compared with eEP(Ctrl) and eSF(Ctrl) and IL-6 in eEP(PCOS) compared with eEP(Ctrl).

CONCLUSIONS

Isolated endometrial cell populations in women with PCOS showed altered gene expression revealing inflammation and prooncogenic changes, independent of body mass index, especially in eEP(PCOS) and eMSC(PCOS), compared with controls. The study reveals an endometrial disease phenotype in women with PCOS with potential negative effects on endometrial function and long-term health.

Perifosine, an AKT inhibitor, modulates ovarian cancer cell line sensitivity to cisplatin-induced growth arrest

OBJECTIVES

AKT, a key regulator of diverse tumor signaling, is associated with progression of many cancers. Here, we investigated 1) the influence of AKT on survival from ovarian cancer (OVCA), 2) the activity of the AKT inhibitor perifosine ± cisplatin, and 3) the molecular determinants of perifosine-response. Phospho-AKT expression values and Affymetrix U133a expression data were downloaded from The Cancer Genome Atlas.

METHODS

Pearson correlation was used to determine associations between overall survival from OVCA and therapy response. Genes and represented signaling pathways associated with perifosine-response were explored in OVCA cells (n=10) and the NCI60 cancer cell panel. Pathway expressions, modeled by PCA, were evaluated for influences on survival using publically available clinico-genomic datasets.

RESULTS

Phospho-AKT (serine473) expression correlated with survival from OVCA (P<0.05) and platinum-response (P=0.004). In vitro, perifosine showed anti-proliferative effects against OVCA cells and potentiated cisplatin-induced growth arrest. Perifosine-response was associated with the expression (FDR<0.05) of 7 signaling pathways in OVCA cells and 64 signaling pathways in the NCI60 cell panel. Three pathways were found in common: 1) Cytoskeleton remodeling/cytoskeleton remodeling (cyto), 2) cell adhesion/chemokines and adhesion (chemokines), and 3) cytoskeleton remodeling/TGF-WNT (TGF-WNT). The TGF-WNT was associated with survival from OVCA (P=0.0055).

CONCLUSIONS

AKT signaling is an important determinant of OVCA response to chemotherapy and overall patient survival. Our data provide insight into the molecular basis to perifosine activity and identifies pathways associated with perifosine sensitivity and patient clinical outcome.

Association of Wnt2 and sFRP4 expression in the third trimester placenta in women with severe preeclampsia

BACKGROUND

The Wnt signaling pathway is a conserved pathway and plays a crucial role in regulating trophoblast functions. Abnormal expression of the Wnt pathway may result in the dysfunction of the trophoblast that can contribute to the pathogenesis of preeclampsia (PE). However, published data regarding the association between Wnt pathway and PE in human pregnancy is rare.

OBJECTIVE

The aims of this study were to investigate the expression pattern of Wnt2 and secreted frizzled-related protein 4 (sFRP4) in the third trimester human placenta and to evaluate the relationship between changes in placental Wnt2 and sFRP4 expression and severe PE.

METHODS

The expression of Wnt2 and sFRP4 in normal and severe PE placentas was examined using immunohistochemistry (IHC), real-time polymerase chain reaction, and Western blot.

RESULTS

Compared to the controls, the relative expression of Wnt2 messenger RNA was remarkably downregulated in the PE placentas, while there was no significant difference in sFRP4 between the 2 groups. The IHC indicated that Wnt2 and sFRP4 were expressed predominantly in the villous syncytiotrophoblast and the extravillous trophoblast, whereas Wnt2 in the control group showed higher staining intensity than in the PE group, and sFRP4 in the PE group had a higher staining intensity than in the control group. Furthermore, the results of the Western blots were consistent with the IHC.

CONCLUSIONS

The Wnt signaling pathway was detected in human third trimester placentas, and the decreased placental expression of Wnt2 and increased placental expression of sFRP4 may be associated with the pathogenesis of severe PE.