WNT7A/β-catenin signaling induces FGF1 and influences sensitivity to niclosamide in ovarian cancer

PAX1 represses canonical Wnt signaling pathway and plays dual roles during endoderm differentiation

BACKGROUND

Paired box 1 (PAX1) is a transcription factor and essential for the development of pharyngeal pouches-derived tissues, including thymus. PAX1 mutations are identified in Severe Combined Immunodeficiency (SCID) patients with Otofaciocervical Syndrome Type 2 (OTFCS2). However, despite the critical roles of PAX1 in embryonic development and diseases, detailed insights into its molecular mode of action are critically missing.

METHODS

The repressing roles of PAX1 and SCID associated mutants on Wnt signaling pathway were investigated by luciferase reporter assays, qRT-PCR and in situ hybridization in HEK293FT, HCT116 cells and zebrafish embryos, respectively. Co-immunoprecipitation (co-IP) and western blotting assays were carried out to identify the molecular mechanisms underlying PAX1's role on Wnt signaling pathway. hESC based endoderm differentiation, flow cytometry, high-throughput sequencing data analysis, and qRT-PCR assays were utilized to determine the roles of PAX1 during endoderm differentiation.

RESULTS

Here, we show that PAX1 represses canonical Wnt signaling pathway in vertebrate cells. Mechanically, PAX1 competes with SUMO E3 ligase PIASy to bind to TCF7L2, thus perturbing TCF7L2 SUMOylation level, further reducing its transcriptional activity and protein stability. Moreover, we reveal that PAX1 plays dual roles in hESC-derived definitive and foregut/pharyngeal endoderm cells, which give rise to the thymus epithelium, by inhibiting Wnt signaling. Importantly, our data show PAX1 mutations found in SCID patients significantly compromise the suppressing ability of PAX1 on Wnt signaling.

CONCLUSIONS

Our study presents a novel molecular mode of action of PAX1 in regulation of canonical Wnt signaling and endoderm differentiation, thus providing insights for the molecular basis of PAX1 associated SCID, offering better understanding of the behavior of PAX1 in embryogenesis.

Down-regulated Wnt7a and GPR124 in early-onset preeclampsia placentas reduce invasion and migration of trophoblast cells

OBJECTIVES

Preeclampsia (PE) is a disease specific to pregnancy that causes 9-10 % of maternal deaths. Early-onset PE (<34 weeks' gestation) is the most dangerous category of PE. Wnt7a and GPR124 (G protein-coupled receptor 124) are widely expressed in the human reproductive process. Especially during embryogenesis and tumorigenesis, Wnt7a plays a crucial role. However, few studies have examined the association between Wnt7a-GPR124 and early-onset PE. The aim of this study was to examine the significance of Wnt7a and GPR124 in early-onset PE as well as Wnt7a's role in trophoblast cells.

METHODS

Immunohistochemistry (IHC), real-time PCR, and western blotting (WB) were used to investigate Wnt7a and GPR124 expression in normal and early-onset PE placentas. Additionally, FACS, Transwell, and CCK-8 assays were used to diagnose Wnt7a involvement in migration, invasion, and proliferation.

RESULTS

In the early-onset PE group, Wnt7a and GPR124 expression was significantly lower than in the normal group, especially in the area of syncytiotrophoblasts (STBs) and extravillous trophoblasts (EVTs). A negative correlation was found between Wnt7a RNA and GPR124 expression (r=-0.42, p<0.01). However, the Wnt7a RNA expression level was positive correlated with PE severity. In further cellular functional experiments, knockdown of Wnt7a inhibits HTR8/SVeno cells invasion and migration but has little effect on proliferation and apoptosis.

CONCLUSIONS

Through the Wnt pathway, Wnt7a regulates trophoblast cell invasion and migration, and may contribute to early-onset preeclampsia pathogenesis. A molecular level study of Wnt7a will be needed to find downstream proteins and mechanisms of interaction.

Single-cell transcriptomics identifies a WNT7A-FZD5 signaling axis that maintains fallopian tube stem cells in patient-derived organoids

The study of fallopian tube (FT) function in health and disease has been hampered by limited knowledge of FT stem cells and lack of in vitro models of stem cell renewal and differentiation. Using optimized organoid culture conditions to address these limitations, we find that FT stem cell renewal is highly dependent on WNT/β-catenin signaling and engineer endogenous WNT/β-catenin signaling reporter organoids to biomark, isolate, and characterize these cells. Using functional approaches, as well as bulk and single-cell transcriptomics analyses, we show that an endogenous hormonally regulated WNT7A-FZD5 signaling axis is critical for stem cell renewal and that WNT/β-catenin pathway-activated cells form a distinct transcriptomic cluster of FT cells enriched in extracellular matrix (ECM) remodeling and integrin signaling pathways. Overall, we provide a deep characterization of FT stem cells and their molecular requirements for self-renewal, paving the way for mechanistic work investigating the role of stem cells in FT health and disease.

MicroRNA-143 as a potential tumor suppressor in cancer: An insight into molecular targets and signaling pathways

MicroRNAs (MiRNAs), which are highly conserved and small noncoding RNAs, negatively regulate gene expression and influence signaling pathways involved in essential biological activities, including cell proliferation, differentiation, apoptosis, and cell invasion. MiRNAs have received much attention in the past decade due to their significant roles in cancer development. In particular, microRNA-143 (miR-143) is recognized as a tumor suppressor and is downregulated in most cancers. However, it seems that miR-143 is upregulated in rare cases, such as prostate cancer stem cells, and acts as an oncogene. The present review will outline the current studies illustrating the impact of miR-143 expression levels on cancer progression and discuss its target genes and their relevant signaling pathways to discover a potential therapeutic way for cancer.

Repurposing approved non-oncology drugs for cancer therapy: a comprehensive review of mechanisms, efficacy, and clinical prospects

Cancer poses a significant global health challenge, with predictions of increasing prevalence in the coming years due to limited prevention, late diagnosis, and inadequate success with current therapies. In addition, the high cost of new anti-cancer drugs creates barriers in meeting the medical needs of cancer patients, especially in developing countries. The lengthy and costly process of developing novel drugs further hinders drug discovery and clinical implementation. Therefore, there has been a growing interest in repurposing approved drugs for other diseases to address the urgent need for effective cancer treatments. The aim of this comprehensive review is to provide an overview of the potential of approved non-oncology drugs as therapeutic options for cancer treatment. These drugs come from various chemotherapeutic classes, including antimalarials, antibiotics, antivirals, anti-inflammatory drugs, and antifungals, and have demonstrated significant antiproliferative, pro-apoptotic, immunomodulatory, and antimetastatic properties. A systematic review of the literature was conducted to identify relevant studies on the repurposing of approved non-oncology drugs for cancer therapy. Various electronic databases, such as PubMed, Scopus, and Google Scholar, were searched using appropriate keywords. Studies focusing on the therapeutic potential, mechanisms of action, efficacy, and clinical prospects of repurposed drugs in cancer treatment were included in the analysis. The review highlights the promising outcomes of repurposing approved non-oncology drugs for cancer therapy. Drugs belonging to different therapeutic classes have demonstrated notable antitumor effects, including inhibiting cell proliferation, promoting apoptosis, modulating the immune response, and suppressing metastasis. These findings suggest the potential of these repurposed drugs as effective therapeutic approaches in cancer treatment. Repurposing approved non-oncology drugs provides a promising strategy for addressing the urgent need for effective and accessible cancer treatments. The diverse classes of repurposed drugs, with their demonstrated antiproliferative, pro-apoptotic, immunomodulatory, and antimetastatic properties, offer new avenues for cancer therapy. Further research and clinical trials are warranted to explore the full potential of these repurposed drugs and optimize their use in treating various cancer types. Repurposing approved drugs can significantly expedite the process of identifying effective treatments and improve patient outcomes in a cost-effective manner.

Niclosamide (NA) overcomes cisplatin resistance in human ovarian cancer

Ovarian cancer (OC) is one of the most lethal malignancies of the female reproductive system. OC patients are usually diagnosed at advanced stages due to the lack of early diagnosis. The standard treatment for OC includes a combination of debulking surgery and platinum-taxane chemotherapy, while several targeted therapies have recently been approved for maintenance treatment. The vast majority of OC patients relapse with chemoresistant tumors after an initial response. Thus, there is an unmet clinical need to develop new therapeutic agents to overcome the chemoresistance of OC. The anti-parasite agent niclosamide (NA) has been repurposed as an anti-cancer agent and exerts potent anti-cancer activities in human cancers including OC. Here, we investigated whether NA could be repurposed as a therapeutic agent to overcome cisplatin-resistant (CR) in human OC cells. To this end, we first established two CR lines SKOV3CR and OVCAR8CR that exhibit the essential biological characteristics of cisplatin resistance in human cancer. We showed that NA inhibited cell proliferation, suppressed cell migration, and induced cell apoptosis in both CR lines at a low micromole range. Mechanistically, NA inhibited multiple cancer-related pathways including AP1, ELK/SRF, HIF1, and TCF/LEF, in SKOV3CR and OVCAR8CR cells. NA was further shown to effectively inhibit xenograft tumor growth of SKOV3CR cells. Collectively, our findings strongly suggest that NA may be repurposed as an efficacious agent to combat cisplatin resistance in chemoresistant human OC, and further clinical trials are highly warranted.

Phenolic Acids-Mediated Regulation of Molecular Targets in Ovarian Cancer: Current Understanding and Future Perspectives

Cancer is a global health concern with a dynamic rise in occurrence and one of the leading causes of mortality worldwide. Among different types of cancer, ovarian cancer (OC) is the seventh most diagnosed malignant tumor, while among the gynecological malignancies, it ranks third after cervical and uterine cancer and sadly bears the highest mortality and worst prognosis. First-line treatments have included a variety of cytotoxic and synthetic chemotherapeutic medicines, but they have not been particularly effective in extending OC patients' lives and are associated with side effects, recurrence risk, and drug resistance. Hence, a shift from synthetic to phytochemical-based agents is gaining popularity, and researchers are looking into alternative, cost-effective, and safer chemotherapeutic strategies. Lately, studies on the effectiveness of phenolic acids in ovarian cancer have sparked the scientific community's interest because of their high bioavailability, safety profile, lesser side effects, and cost-effectiveness. Yet this is a road less explored and critically analyzed and lacks the credibility of the novel findings. Phenolic acids are a significant class of phytochemicals usually considered in the nonflavonoid category. The current review focused on the anticancer potential of phenolic acids with a special emphasis on chemoprevention and treatment of OC. We tried to summarize results from experimental, epidemiological, and clinical studies unraveling the benefits of various phenolic acids (hydroxybenzoic acid and hydroxycinnamic acid) in chemoprevention and as anticancer agents of clinical significance.

Guiding Drug Repositioning for Cancers Based on Drug Similarity Networks

Drug repositioning aims to discover novel clinical benefits of existing drugs, is an effective way to develop drugs for complex diseases such as cancer and may facilitate the process of traditional drug development. Meanwhile, network-based computational biology approaches, which allow the integration of information from different aspects to understand the relationships between biomolecules, has been successfully applied to drug repurposing. In this work, we developed a new strategy for network-based drug repositioning against cancer. Combining the mechanism of action and clinical efficacy of the drugs, a cancer-related drug similarity network was constructed, and the correlation score of each drug with a specific cancer was quantified. The top 5% of scoring drugs were reviewed for stability and druggable potential to identify potential repositionable drugs. Of the 11 potentially repurposable drugs for non-small cell lung cancer (NSCLC), 10 were confirmed by clinical trial articles and databases. The targets of these drugs were significantly enriched in cancer-related pathways and significantly associated with the prognosis of NSCLC. In light of the successful application of our approach to colorectal cancer as well, it provides an effective clue and valuable perspective for drug repurposing in cancer.

Salicylanilides and Their Anticancer Properties

Salicylanilides are pharmacologically active compounds with a wide spectrum of biological effects. Halogenated salicylanilides, which have been used for decades in human and veterinary medicine as anthelmintics, have recently emerged as candidates for drug repurposing in oncology. The most prominent example of salicylanilide anthelmintic, that is intensively studied for its potential anticancer properties, is niclosamide. Nevertheless, recent studies have discovered extensive anticancer potential in a number of other salicylanilides. This potential of their anticancer action is mediated most likely by diverse mechanisms of action such as uncoupling of oxidative phosphorylation, inhibition of protein tyrosine kinase epidermal growth factor receptor, modulation of different signaling pathways as Wnt/β-catenin, mTORC1, STAT3, NF-κB and Notch signaling pathways or induction of B-Raf V600E inhibition. Here we provide a comprehensive overview of the current knowledge about the proposed mechanisms of action of anticancer activity of salicylanilides based on preclinical in vitro and in vivo studies, or structural requirements for such an activity.

Niclosamide targets the dynamic progression of macrophages for the resolution of endometriosis in a mouse model

Due to the vital roles of macrophages in the pathogenesis of endometriosis, targeting macrophages could be a promising therapeutic direction. Here, we investigated the efficacy of niclosamide for the resolution of a perturbed microenvironment caused by dysregulated macrophages in a mouse model of endometriosis. Single-cell transcriptomic analysis revealed the heterogeneity of macrophages including three intermediate subtypes with sharing characteristics of traditional “small” or “large” peritoneal macrophages (SPMs and LPMs) in the peritoneal cavity. Endometriosis-like lesions (ELL) enhanced the differentiation of recruited macrophages, promoted the replenishment of resident LPMs, and increased the ablation of embryo-derived LPMs, which were stepwise suppressed by niclosamide. In addition, niclosamide restored intercellular communications between macrophages and B cells. Therefore, niclosamide rescued the perturbed microenvironment in endometriosis through its fine regulations on the dynamic progression of macrophages. Validation of similar macrophage pathogenesis in patients will further promote the clinical usage of niclosamide for endometriosis treatment.

LHX2 facilitates the progression of nasopharyngeal carcinoma via activation of the FGF1/FGFR axis

BACKGROUND

Distant metastasis and recurrence remain the main obstacle to nasopharyngeal carcinoma (NPC) treatment. However, the molecular mechanisms underlying NPC growth and metastasis are poorly understood.

METHODS

LHX2 expression was examined in NPC cell lines and NPC tissues using quantitative reverse transcription-polymerase chain reaction, western blotting and Immunohistochemistry assay. NPC cells overexpressing or silencing LHX2 were used to perform CCK-8 assay, colony-formation assay, EdU assay, wound-healing and invasion assays in vitro. Xenograft tumour models and lung metastasis models were involved for the in vivo assays. The Gene Set Enrichment Analysis (GSEA), ELISA assay, western blot, chromatin immunoprecipitation (ChIP) assay and Luciferase reporter assay were applied for the downstream target mechanism investigation.

RESULTS

LIM-homeodomain transcription factor 2 (LHX2) was upregulated in NPC tissues and cell lines. Elevated LHX2 was closely associated with poor survival in NPC patients. Ectopic LHX2 overexpression dramatically promoted the growth, migration and invasion of NPC cells both in vitro and in vivo. Mechanistically, LHX2 transcriptionally increased the fibroblast growth factor 1 (FGF1) expression, which in turn activated the phosphorylation of STAT3 (signal transducer and activator of transcription 3), ERK1/2 (extracellular regulated protein kinases 1/2) and AKT signalling pathways in an autocrine and paracrine manner, thereby promoting the growth and metastasis of NPC. Inhibition of FGF1 with siRNA or FGFR inhibitor blocked LHX2-induced nasopharyngeal carcinoma cell growth, migration and invasion.

CONCLUSIONS

Our study identifies the LHX2-FGF1-FGFR axis plays a key role in NPC progression and provides a potential target for NPC therapy.

Anti-Müllerian Hormone Signal Transduction involved in Müllerian Duct Regression

Over seventy years ago it was proposed that the fetal testis produces a hormone distinct from testosterone that is required for complete male sexual development. At the time the hormone had not yet been identified but was invoked by Alfred Jost to explain why the Müllerian duct, which develops into the female reproductive tract, regresses in the male fetus. That hormone, anti-Müllerian hormone (AMH), and its specific receptor, AMHR2, have now been extensively characterized and belong to the transforming growth factor-β families of protein ligands and receptors involved in growth and differentiation. Much is now known about the downstream events set in motion after AMH engages AMHR2 at the surface of specific Müllerian duct cells and initiates a cascade of molecular interactions that ultimately terminate in the nucleus as activated transcription factors. The signals generated by the AMH signaling pathway are then integrated with signals coming from other pathways and culminate in a complex gene regulatory program that redirects cellular functions and fates and leads to Müllerian duct regression.

Synergistic Inhibitory Effects of 5-Aza-2'-Deoxycytidine and Cisplatin on Urothelial Carcinoma Growth via Suppressing TGFBI-MAPK Signaling Pathways

This study is to reveal the gene transcriptional alteration, possible molecular mechanism, and pathways involved in the synergy of 5-aza-2'-deoxycytidine (DAC) and CDDP in UC. Two UC cell lines, 5637 and T24, were used in the study. A cDNA microarray was carried out to identify critical genes in the synergistic mechanism of both agents against UC cells. The results showed that several key regulatory genes, such as interleukin 24(IL24), fibroblast growth factor 1(FGF1), and transforming growth factor beta-induced (TGFBI), were identified and may play critical roles in the synergy of DAC and CDDP in UC. Pathway enrichment suggested that many carcinogenesis-related pathways, such as ECM-receptor interaction and MAPK signaling pathways, may participate in the synergy of both agents. Our results suggested that TGF-β1 stimulates the phosphorylation levels of ERK1/2 and p38 via increasing TGFBI expression, TGFBI-MAPK signaling pathway plays an important role in the synergy of DAC and CDDP against UC. Therefore, we revealed the synergistic mechanism of DAC and CDDP in UC, several key regulatory genes play critical roles in the synergy of combined treatment, and TGFBI-MAPK signaling pathway may be an important potential target of these two agents.

Nitro-Deficient Niclosamide Confers Reduced Genotoxicity and Retains Mitochondrial Uncoupling Activity for Cancer Therapy

Niclosamide is an oral anthelmintic drug, approved for use against tapeworm infections. Recent studies suggest however that niclosamide may have broader clinical applications in cancers, spurring increased interest in the functions and mechanisms of niclosamide. Previously, we reported that niclosamide targets a metabolic vulnerability in p53-deficient tumours, providing a basis for patient stratification and personalised treatment strategies. In the present study, we functionally characterised the contribution of the aniline 4'-NO2 group on niclosamide to its cellular activities. We demonstrated that niclosamide induces genome-wide DNA damage that is mechanistically uncoupled from its antitumour effects mediated through mitochondrial uncoupling. Elimination of the nitro group in ND-Nic analogue significantly reduced γH2AX signals and DNA breaks while preserving its antitumour mechanism mediated through a calcium signalling pathway and arachidonic acid metabolism. Lipidomics profiling further revealed that ND-Nic-treated cells retained a metabolite profile characteristic of niclosamide-treated cells. Notably, quantitative scoring of drug sensitivity suggests that elimination of its nitro group enhanced the target selectivity of niclosamide against p53 deficiency. Importantly, the results also raise concern that niclosamide may impose a pleiotropic genotoxic effect, which limits its clinical efficacy and warrants further investigation into alternative drug analogues that may ameliorate any potential unwanted side effects.

The Association of Aberrant Expression of FGF1 and mTOR-S6K1 in Colorectal Cancer

Colorectal cancer (CRC) is one of the most frequent malignant neoplasms worldwide, and the effect of treatments is limited. Fibroblast growth factor 1 (FGF1) has been involved in a wide variety of several malignant diseases and takes part in the tumorigenesis of CRC. However, the function and mechanism of FGF1 in CRC remains elusive. In this study, the results indicated that FGF1 is elevated in CRC tissues and linked with poor prognosis (P < 0.001). In subgroup analysis of FGF1 in CRC, regardless of any clinic-factors except gender, high level FGF1 expression was associated with markedly shorter survival (P < 0.05). In addition, the expression of p-S6K1 and FGF1 was not associated in normal tissue (P = 0.781), but their expression was closely related in tumor tissue (P = 0.010). The oncogenic role of FGF1 was determined using in vitro and in vivo functional assays. FGF1 depletion inhibited the proliferation and migration of CRC cells in vitro and vivo. FGF1 was also significantly correlated with mTOR-S6K1 pathway on the gene and protein levels (P < 0.05). In conclusion, FGF1 acts as a tumor activator in CRC, and against FGF1 may provide a new visual field on treating CRC, especially for mTORC1-targeted resistant patients.

Niclosamide suppresses macrophage-induced inflammation in endometriosis†

Endometriosis is a common gynecological disease, which causes chronic pelvic pain and infertility in women of reproductive age. Due to limited efficacy of current treatment options, a critical need exists to develop new and effective treatments for endometriosis. Niclosamide is an efficacious and FDA-approved drug for the treatment of helminthosis in humans that has been used for decades. We have reported that niclosamide reduces growth and progression of endometriosis-like lesions via targeting STAT3 and NFĸB signaling in a mouse model of endometriosis. To examine the effects of niclosamide on macrophage-induced inflammation in endometriosis, a total of 29 stage III-IV endometrioma samples were used to isolate human endometriotic stromal cells (hESCs). M1 or M2 macrophages were isolated and differentiated from fresh human peripheral blood samples. Then, hESCs were cultured in conditioned media (CM) from macrophages with/without niclosamide. Niclosamide dose dependently reduced cell viability and the activity of STAT3 and NFκB signaling in hESCs. While macrophage CM stimulated cell viability in hESCs, niclosamide inhibited this stimulation. Macrophage CM stimulated the secretion of proinflammatory cytokines and chemokines from hESCs. Most of these secreted factors were inhibited by niclosamide. These results indicate that niclosamide is able to reduce macrophage-induced cell viability and cytokine/chemokine secretion in hESCs by inhibiting inflammatory mechanisms via STAT3 and/or NFκB signaling.

Targeting Wnt Signaling in Endometrial Cancer

Simple Summary

Wnt has diverse regulatory roles at multiple cellular levels and numerous targeting points, and aberrant Wnt signaling has crucial roles in carcinogenesis, metastasis, cancer recurrence, and chemotherapy resistance; based on these facts, Wnt represents an appealing therapeutic target for cancer treatment. Although preclinical data supports a role for the Wnt signaling pathway in uterine carcinogenesis, this area remains understudied. In this review, we identify the functions of several oncogenes of the Wnt/β-catenin signaling pathway in tumorigenesis and address the translation approach with potent Wnt inhibitors that have already been established or are being investigated to target key components of the pathway. Further research is likely to expand the potential for both biomarker and cancer drug development. There is a scarcity of treatment choices for advanced and recurrent endometrial cancer; investigating the sophisticated connections of Wnt signaling networks in endometrial cancer could address the unmet need for new therapeutic targets.

Abstract

This review presents new findings on Wnt signaling in endometrial carcinoma and implications for possible future treatments. The Wnt proteins are essential mediators in cell signaling during vertebrate embryo development. Recent biochemical and genetic studies have provided significant insight into Wnt signaling, in particular in cell cycle regulation, inflammation, and cancer. The role of Wnt signaling is well established in gastrointestinal and breast cancers, but its function in gynecologic cancers, especially in endometrial cancers, has not been well elucidated. Development of a subset of endometrial carcinomas has been attributed to activation of the APC/β-catenin signaling pathway (due to β-catenin mutations) and downregulation of Wnt antagonists by epigenetic silencing. The Wnt pathway also appears to be linked to estrogen and progesterone, and new findings implicate it in mTOR and Hedgehog signaling. Therapeutic interference of Wnt signaling remains a significant challenge. Herein, we discuss the Wnt-activating mechanisms in endometrial cancer and review the current advances and challenges in drug discovery.

Niclosamide's potential direct targets in ovarian cancer†

Recent evidence indicates that niclosamide is an anti-cancer compound that is able to inhibit several signaling pathways. Although niclosamide has previously been identified by high-throughput screening platforms as a potential effective compound against several cancer types, no direct binding interactions with distinct biological molecule(s) has been established. The present study identifies key signal transduction mechanisms altered by niclosamide in ovarian cancer. Using affinity purification with a biotin-modified niclosamide derivative and mass spectrometry analysis, several RNA-binding proteins (RBPs) were identified. We chose the two RBPs, FXR1 and IGF2BP2, for further analysis. A significant correlation exists in which high-expression of FXR1 or IGF2BP2 is associated with reduced survival of ovarian cancer patients. Knockdown of FXR1 or IGF2BP2 in ovarian cancer cells resulted in significantly reduced cell viability, adhesion, and migration. Furthermore, FXR1 or IGF2BP2 deficient ovarian cancer cells exhibited reduced response to most doses of niclosamide showing greater cell viability than those with intact RBPs. These results suggest that FXR1 and IGF2BP2 are direct targets of niclosamide and could have critical activities that drive multiple oncogenic pathways in ovarian cancer.

The Role of miR-640: A Potential Suppressor in Breast Cancer via Wnt7b/β-catenin Signaling Pathway

In this study, we demonstrated that miR-640 is significantly downregulated in breast cancer (BC) tissues and cell lines. Overexpression of miR-640 inhibited the proliferation and migration of BC in vitro and in vivo, while depletion of miR-640 exhibited the opposite effect. Importantly, miR-640 could directly target Wnt7b, thereby regulating Wnt/β-catenin signaling pathway in BC. In conclusion, miR-640/Wnt7b suppresses BC cells tumorigenesis via Wnt/β-catenin signaling pathway, which might be novel targets for BC targeted therapy.

LGR4 maintains HGSOC cell epithelial phenotype and stem-like traits

OBJECTIVE

High-grade serous ovarian cancer (HGSOC) is lethal mainly due to extensive metastasis. Cancer cell stem-like properties are responsible for HGSOC metastasis. LGR4, a G-protein-coupled receptor, is involved in the maintenance of stem cell self-renewal and activity in some human organs.

METHODS

TCGA and CCLE databases were interrogated for gene mRNA in ovarian cancer tissues and cell lines. Gain and loss of functions of LGR4, ELF3, FZD5 and WNT7B were performed to identify their roles in ovarian cancer cell epithelial phenotype and stem-like properties. In vivo experiments were performed to observe the effect of LGR4 on ovarian cancer cell growth and peritoneal seeding. The binding of ELF3 to LGR4 gene promoter was investigated by dual-luciferase reporter assays and ChIP.

RESULTS

LGR4 was shown to be overexpressed in HGSOCs and maintain the epithelial phenotype of HGSOC cells. LGR4 knockdown suppressed POU5F1, SOX2, PROM1 (CD133) and ALDH1A2 expression. Furthermore, LGR4 knockdown reduced CD133⁺ and ALDH⁺ subpopulations and impaired tumorisphere formation. To the contrary, LGR4 overexpression enhanced POU5F1 and SOX2 expression and tumorisphere formation capacity. LGR4 knockdown inhibited HGSOC cell growth and peritoneal seeding in xenograft models. Mechanistically, LGR4 and ELF3, an epithelium-specific transcription factor, formed a reciprocal regulatory loop, which was positively modulated by WNT7B/FZD5 ligand-receptor pair. Consistently, knockdown of ELF3, WNT7B, and FZD5, respectively, disrupted HGSOC cell epithelial phenotype and stem-like properties.

CONCLUSION

Together, these data demonstrate that WNT7B/FZD5-LGR4/ELF3 axis maintains HGSOC cell epithelial phenotype and stem-like traits; targeting this axis may prevent HGSOC metastasis.

Bioinformatic analysis reveals MIR502 as a potential tumour suppressor in ovarian cancer

BACKGROUND

Ovarian cancer (OC) is a major cause of death among women due to the lack of early screening methods and its complex pathological progression. Increasing evidence has indicated that microRNAs regulate gene expression in tumours by interacting with mRNAs. Although the research regarding OC and microRNAs is extensive, the vital role of MIR502 in OC remains unclear.

METHODS

We integrated two microRNA expression arrays from GEO to identify differentially expressed genes. The Kaplan-Meier method was used to screen for miRNAs that had an influence on survival outcome. Upstream regulators of MIR502 were predicted by JASPAR and verified by ChIP-seq data. The LinkedOmics database was used to study genes that were correlated with MIR502. Gene Set Enrichment Analysis (GSEA) was conducted for functional annotation with GO and KEGG pathway enrichment analyses by using the open access WebGestalt tool. We constructed a PPI network by using STRING to further explore the core proteins.

RESULTS

We found that the expression level of MIR502 was significantly downregulated in OC, which was related to poor overall survival. NRF1, as an upstream regulator of MIR502, was predicted by JASPAR and verified by ChIP-seq data. In addition, anti-apoptosis and pro-proliferation genes in the Hippo signalling pathway, including CCND1, MYC, FGF1 and GLI2, were negatively regulated by MIR502, as shown in the GO and KEGG pathway enrichment results. The PPI network further demonstrated that CCND1 and MYCN were at core positions in the development of ovarian cancer.

CONCLUSIONS

MIR502, which is regulated by NRF1, acts as a tumour suppressor gene to accelerate apoptosis and suppress proliferation by targeting the Hippo signalling pathway in ovarian cancer.

Loss of AKR1B10 promotes colorectal cancer cells proliferation and migration via regulating FGF1-dependent pathway

Colorectal cancer (CRC) is a common malignancy worldwide with poor prognosis and survival rates. The aldo-keto reductase family 1 member B10 (AKR1B10) plays an important role in metabolism, cell proliferation and mobility, and is downregulated in CRC. We hypothesized that AKR1B10 would promote CRC genesis via a noncanonical oncogenic pathway and is a novel therapeutic target. In this study, AKR1B10 expression levels in 135 pairs of CRC and para-tumor tissues were examined, and its oncogenic role was determined using in vitro and in vivo functional assays following genetic manipulation of CRC cells. AKR1B10 was downregulated in CRC tissues compared to the adjacent normal colorectal tissues, and associated with the clinicopathological status of the patients. AKR1B10 depletion promoted the proliferation and migration of CRC cells in vitro, while its ectopic expression had the opposite effect. AKR1B10 was also significantly correlated with FGF1 gene and protein levels. Knockdown of AKR1B10 promoted tumor growth in vivo, and increased the expression of FGF1. Finally, AKR1B10 inhibited FGF1, and suppressed the proliferation and migration ability of CRC cells in an FGF1-dependent manner. In conclusion, AKR1B10 acts as a tumor suppressor in CRC by inactivating FGF1, and is a novel target for combination therapy of CRC.

Overcoming cancer therapeutic bottleneck by drug repurposing

Ever present hurdles for the discovery of new drugs for cancer therapy have necessitated the development of the alternative strategy of drug repurposing, the development of old drugs for new therapeutic purposes. This strategy with a cost-effective way offers a rare opportunity for the treatment of human neoplastic disease, facilitating rapid clinical translation. With an increased understanding of the hallmarks of cancer and the development of various data-driven approaches, drug repurposing further promotes the holistic productivity of drug discovery and reasonably focuses on target-defined antineoplastic compounds. The "treasure trove" of non-oncology drugs should not be ignored since they could target not only known but also hitherto unknown vulnerabilities of cancer. Indeed, different from targeted drugs, these old generic drugs, usually used in a multi-target strategy may bring benefit to patients. In this review, aiming to demonstrate the full potential of drug repurposing, we present various promising repurposed non-oncology drugs for clinical cancer management and classify these candidates into their proposed administration for either mono- or drug combination therapy. We also summarize approaches used for drug repurposing and discuss the main barriers to its uptake.

Exogenous Expression of WNT7A in Leukemia-Derived Cell Lines Induces Resistance to Chemotherapeutic Agents

BACKGROUND

Dysregulations of the WNT pathway are implicated in the malignant transformation of different types of neoplasia. WNT7A is expressed in normal peripheral lymphocytes, but is decreased in the tumoral counterpart. Furthermore, the treatment of leukemic cells with recombinant WNT7A decreases proliferation, suggesting its possible use as a therapeutic biomolecule. This study aimed to evaluate the concomitant action of WNT7A and different chemotherapeutic agents over proliferation and cell death of leukemia/ lymphoma derived cell lines.

METHODS

Ectopic expression of WNT7A was induced in CEM and BJAB cell lines by using a lentiviral system. RNA expression was analyzed by microarrays and qPCR, and protein expression was determined by Western Blot. Cell proliferation was measured by cell counting, metabolic activity by WST-1 assay, cell death and DNA content by flow cytometry.

RESULTS

WNT7A ectopic expression was shown to decrease cell proliferation, but the apoptosis rate of leukemic cells was not altered. Moreover, these cells acquired resistance to doxorubicin, vincristine and MG-132. Cell cycle analysis reveals a decrease in G1 and an increase in S and G2 phases with a further upregulation of senescence- associated genes. Microarray analysis reveals that most gene expression changes were related to cancer and metabolic associated pathways. All those changes appear to be independent of the WNT canonical pathway regulation.

CONCLUSION

WNT7A negatively regulates cell proliferation in leukemic cell lines and promotes resistance to chemotherapeutic agents by inducing a senescence-like phenotype independently of the WNT canonical pathway.

Endometriotic inflammatory microenvironment induced by macrophages can be targeted by niclosamide†

Endometriosis causes severe chronic pelvic pain and infertility. We have recently reported that niclosamide treatment reduces growth and progression of endometriosis-like lesions and inflammatory signaling (NF${\rm \small K}$B and STAT3) in a mouse model. In the present study, we examined further inhibitory mechanisms by which niclosamide affects endometriotic lesions using an endometriotic epithelial cell line, 12Z, and macrophages differentiated from a monocytic THP-1 cell line. Niclosamide dose dependently reduced 12Z viability, reduced STAT3 and NF${\rm \small K}$B activity, and increased both cleaved caspase-3 and cleaved PARP. To model the inflammatory microenvironment in endometriotic lesions, we exposed 12Z cells to macrophage conditioned media (CM). Macrophages were differentiated from THP-1 cells using 12-O-tetradecanoylphorbol-13-acetate as M0, and then M0 macrophages were polarized into M1 or M2 using LPS/IFNγ or IL4/IL13, respectively. Conditioned media from M0, M1, or M2 cultures increased 12Z viability. This effect was blocked by niclosamide, and cell viability returned to that of CM from cells treated with niclosamide alone. To assess proteins targeted by niclosamide in 12Z cells, CM from 12Z cells cultured with M0, M1, or M2 with/without niclosamide were analyzed by cytokine/chemokine protein array kits. Conditioned media from M0, M1, and/or M2 stimulated the secretion of cytokines/chemokines from 12Z cells. Production of most of these secreted cytokines/chemokines in 12Z cells was inhibited by niclosamide. Knockdown of each gene in 12Z cells using siRNA resulted in reduced cell viability. These results indicate that niclosamide can inhibit the inflammatory factors in endometriotic epithelial cells stimulated by macrophages by targeting STAT3 and/or NF${\rm \small K}$B signaling.

New drugs are not enough‑drug repositioning in oncology: An update

Drug repositioning refers to the concept of discovering novel clinical benefits of drugs that are already known for use treating other diseases. The advantages of this are that several important drug characteristics are already established (including efficacy, pharmacokinetics, pharmacodynamics and toxicity), making the process of research for a putative drug quicker and less costly. Drug repositioning in oncology has received extensive focus. The present review summarizes the most prominent examples of drug repositioning for the treatment of cancer, taking into consideration their primary use, proposed anticancer mechanisms and current development status.

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.

tRNA-derived fragment tRF-03357 promotes cell proliferation, migration and invasion in high-grade serous ovarian cancer

Background

High-grade serous ovarian cancer (HGSOC) is one of the most common ovarian epithelial malignancies. tRNA-derived fragments (tRFs) have been identified as novel potential biomarkers and targets for cancer therapy. Nevertheless, the influence of tRFs on HGSOC remains unknown. This study aimed to identify HGSOC-associated tRFs and to investigate the function and mechanism of key tRFs in SK-OV-3 ovarian cancer cells.

Methods

The tRF profiles in HGSOC patients and controls were investigated using small RNA sequencing. Differentially expressed tRFs were verified by real-time PCR, and a key tRF was evaluated in a function study.

Results

A total of 27 tRFs were differentially expressed between HGSOC patients and controls. Differentially expressed tRFs were mainly involved in the functions of protein phosphorylation, transcription and cell migration and the pathway of cancer, and the MAPK and Wnt signaling pathways. Real-time PCR verified that tRF-03357 and tRF-03358 were significantly increased in the HGSOC serum samples and SK-OV-3 cells compared to their expression levels in the controls. Importantly, tRF-03357 promoted SK-OV-3 cell proliferation, migration and invasion. Moreover, tRF-03357 was predictively targeted, and significantly downregulated HMBOX1.

Conclusion

This study suggests that tRF-03357 might promote cell proliferation, migration and invasion, partly by modulating HMBOX1 in HGSOC.

Roles of Wnt7a in embryo development, tissue homeostasis, and human diseases

Human Wnt family comprises 19 proteins which are critical to embryo development and tissue homeostasis. Binding to different frizzled (FZD) receptor, Wnt7a initiates both β-catenin dependent pathway, and β-catenin independent pathways such as PI3K/Akt, RAC/JNK, and extracellular signal-regulated kinase 5/peroxisome proliferator-activated receptor-γ. In the embryo, Wnt7a plays a crucial role in cerebral cortex development, synapse formation, and central nervous system vasculature formation and maintenance. Wnt7a is also involved in the development of limb and female reproductive system. Wnt7a mutation leads to human limb malformations and animal female reproductive system defects. Wnt7a is implicated in homeostasis maintenance of skeletal muscle, cartilage, cornea and hair follicle, and Wnt7a treatment may be potentially applied in skeletal muscle dystrophy, corneal damage, wound repair, and hair follicle regeneration. Wnt7a plays dual roles in human tumors. Wnt7a is downregulated in lung cancers, functioning as a tumor suppressor, however, it is upregulated in several other malignancies such as ovarian cancer, breast cancer, and glioma, acting as a tumor promoter. Moreover, Wnt7a overexpression is associated with inflammation and fibrosis, but its roles need to be further investigated.

Niclosamide repositioning for treating cancer: Challenges and nano-based drug delivery opportunities

Drug repositioning may be defined as a process when new biological effects for known drugs are identified, leading to recommendations for new therapeutic applications. Niclosamide, present in the Model List of Essential Medicines, from the World Health Organization, has been used since the 1960s for tapeworm infection. Several preclinical studies have been shown its impressive anticancer effects, which led to clinical trials for colon and prostate cancer. Despite high expectations, proof of efficacy and safety are still required, which are associated with diverse biopharmaceutical challenges, such as the physicochemical properties of the drug and its oral absorption, and their relationship with clinical outcomes. Nanostructured systems are innovative drug delivery strategies, which may provide interesting pharmaceutical advantages for this candidate. The aim of this review is to discuss challenges involving niclosamide repositioning for cancer diseases, and the opportunities of therapeutic benefits from nanosctrutured system formulations containing this compound.

Molecules targeting the androgen receptor (AR) signaling axis beyond the AR-Ligand binding domain

Prostate cancer (PCa) is the second most common cause of cancer-related mortality in men in the United States. The androgen receptor (AR) and the physiological pathways it regulates are central to the initiation and progression of PCa. As a member of the nuclear steroid receptor family, it is a transcription factor with three distinct functional domains (ligand-binding domain [LBD], DNA-binding domain [DBD], and transactivation domain [TAD]) in its structure. All clinically approved drugs for PCa ultimately target the AR-LBD. Clinically active drugs that target the DBD and TAD have not yet been developed due to multiple factors. Despite these limitations, the last several years have seen a rise in the discovery of molecules that could successfully target these domains. This review aims to present and comprehensively discuss such molecules that affect AR signaling through direct or indirect interactions with the AR-TAD or the DBD. The compounds discussed here include hairpin polyamides, niclosamide, marine sponge-derived small molecules (eg, EPI compounds), mahanine, VPC compounds, JN compounds, and bromodomain and extraterminal domain inhibitors. We highlight the significant in vitro and in vivo data found for each compound and the apparent limitations and/or potential for further development of these agents as PCa therapies.

miR-30a inhibits breast cancer progression through the Wnt/β-catenin pathway

BACKGROUND

miR-30a is a microRNA associated with the progression of malignant tumors such as gastric cancer, colon cancer, prostate cancer, and lung cancer, and can regulate the proliferation and migration of breast cancer (BC) cells in vitro. However, its expression, function, clinical significance and relationship with the Wnt/β-catenin pathway in human BC were still unclear.

METHODS

Immunohistochemistry, Western blotting and real-time quantitative PCR (RT-qPCR) were used to measure the expressions of miR-30a and β-catenin in 114 pairs of human BC tumor tissues and adjacent normal tissues which were collected from March 2014 to October 2015. The effect of miR-30a on the expression of β-catenin was studied in the MCF-7 cells in vitro.

RESULTS

The expression levels of miR-30a in human BC tumor tissues were significantly lower than they were in the adjacent normal tissues (P < 0.001), and significantly higher in β-catenin protein (P < 0.001), but there was no significant different in β-catenin mRNA (P = 0.3816). The immunohistochemistry results showed that β-catenin protein was only expressed on the cell membrane in paracancerous normal tissues, but β-catenin protein was expressed on the cell membrane and cytoplasm in BC tumor cells. In addition, there was a significantly negative correlation (r = -0.816, P < 0.001) between the expression miR-30a and β-catenin protein in BC tissues. The age of onset, PR expression, ER expression, and HER-2 expression of the BC patients were not related to miR-30a or β-catenin protein expression (P > 0.05). Tumor diameter, histological grade, lymph node metastasis, TNM stage, and the prognosis of BC patients (P < 0.05) were significantly related to miR-30a or β-catenin protein expression. In MCF-7 cells, miR-30a regulated the accumulation of β-catenin protein by inhibiting the expression of BCL9 in BC cells.

CONCLUSION

miR-30a was lowly expressed in breast cancer tissues and highly in β-catenin protein, and miR-30a might block the Wnt/β-catenin pathway by inhibiting the accumulation of β-catenin, and then inhibiting breast cancer progression.

High expression of WNT7A predicts poor prognosis and promote tumor metastasis in pancreatic ductal adenocarcinoma

Due to the therapy resistance and frequent metastasis, pancreatic ductal adenocarcinoma(PDAC) remains one of the most malignant carcinoma. WNT7A, an important ligand of Wnt/β-catenin signaling pathways, has a controversial role in tumor development. The role of WNT7A in PDAC remains unclear. In this study, we analyzed the expression pattern of WNT7A at mRNA and protein levels. We found pancreatic cancer tissue demonstrated a significant high WNT7A expression compared with the adjacent non-tumor tissue and the expression of WNT7A positively correlates with poor prognosis and lymph node metastasis. Then, we performed transwell assays and wound healing assays in vitro and found that WNT7A promotes the migration capacity of cancer cells. Furthermore, we explored the underlying mechanism of the WNT7A inducing cell migration. Results showed that up-regulated WNT7A expression inducing higher expression of N-cadherin and lower expression of E-cadherin while the contrast result was shown in the WNT7A knock-down group, which suggested that WNT7A might contribute to an epithelial–mesenchymal transition. Finally, we found that the hypoxia culture condition remarkably increased the WNT7A expression. In conclusion, our work demonstrated that hypoxia induced high expression of WNT7A might promote the cell migration via enhancing the epithelial–mesenchymal transition in PDAC.

Niclosamide Inhibits Cell Growth and Enhances Drug Sensitivity of Hepatocellular Carcinoma Cells via STAT3 Signaling Pathway

Aims: Hepatocellular carcinoma (HCC) is the sixth most common malignant tumor worldwide, with a high mortality rate at advanced stages. In this study, we investigated the effect of niclosamide on cell growth and drug sensitivity in human HCC and elucidated the underlying mechanism.

Methods: Three human HCC cell lines (HepG2, QGY-7703 and SMMC-7721) were used to evaluate the effect of niclosamide. Cell proliferation was measured by MTT assay and colony formation assay. Assessment of apoptosis was evaluated by flow cytometry and Hoechst staining. The mRNA and protein levels were analyzed by real-time PCR and western blot, respectively.

Results: Niclosamide suppressed cell viability, inhibited clone formation, and induced cell apoptosis in HCC cells dose- and time-dependently. Furthermore, niclosamide synergized with cisplatin to promote the apoptosis of HCC cells. With niclosamide treatment, phospho-STAT3 (Y705) was inactivated and the downstream antiapoptotic proteins Mcl-1 and survivin were downregulated at both mRNA and protein levels in HCC cells.

Conclusion: Niclosamide has effective function in anti-HCC and may be a single or combined drug treatment for HCC and acts via the STAT3 signaling pathway.

Inhibition of WNT7A-β-catenin signaling pathway sensitizes oral squamous cell carcinoma to cisplatin

Oral squamous cell carcinoma (OSCC) is the most common type and most threatening head and neck cancer worldwide. Here, we aim to study the relationship between the WNT7A-β-Catenin signaling pathway and the chemotherapy resistance of OSCC patients. We analyzed 42 OSCC patients and 19 adjacent non-tumor tissues, evaluated the expression levels of WNT7A mRNA, and subsequently studied WNT7A dependent cisplatin resistance in OSCC cell line KB cells. Moreover, we also utilized an in vivo mouse model to validate our findings. We first found a significant upregulation of WNT7A mRNA in OSCC patients. Our results showed that the knockdown of WNT7A sensitized KB cells to cisplatin. Moreover, our results revealed that nuclear β-catenin was dramatically reduced and cleaved caspase-3 and cleaved PARP were dramatically induced when WNT7A was knocked down in cisplatin treated KB cells. Besides, we found that the knockdown of WNT7A significantly reduced the weight and volumes of xenograft tumors. Moreover, we examined apoptotic cells and found that the combination of WNT7A knockdown and cisplatin treatment resulted in many more apoptotic cells than cisplatin treatment alone, suggesting that the knockdown of WNT7A sensitized KB cells to cisplatin treatment in vivo. Our results revealed that inhibition of WNT7A-β-catenin signaling sensitizes OSCC to cisplatin, which has provided insights into the molecular diagnosis and treatment of OSCC.

Up-regulation of Wnt7b rather than Wnt1, Wnt7a, and Wnt9a indicates poor prognosis in breast cancer

Aberrant activation of Wnt/β-catenin signaling is one of the most frequent abnormalities in human cancer, including breast cancer. The prognostic value of Wnt ligands has never been fully characterized. In this study, we focused on four Wnt ligands, namely Wnt1, Wnt7a, Wnt7b and Wnt9a, which were commonly studied and found pivotal in Wnt/β-catenin signaling, but seldom explored for their prognostic value. We investigated the expression of Wnt1, Wnt7a, Wnt7b and Wnt9a in breast cancer tissues by using real-time PCR and immunohistochemical analysis, and further identified their prognostic significance. Results demonstrated that only Wnt7b expression level in breast cancer was significantly higher than that of benign breast. Spearman rank-correlation analysis revealed the expression level of Wnt1, Wnt7b and Wnt9a, but not Wnt7a, were all significantly associated with positive lymph nodes. The Kaplan-Meier survival curve demonstrated that patients with high Wnt7b expression had a shorter overall survival (OS) and recurrence-free survival (RFS) than those with low Wnt7b expression. Moreover, the univariate and multivariate analysis revealed that Wnt7b expression was an independent prognostic factor for both OS and RFS of breast cancer patients. In addition, the high expression of Wnt7b in breast cancer and its prognostic role were further validated by GENT (Gene Expression database of Normal and Tumor tissues) database and the Kaplan-Meier plotter database. Taken together, we identified that high expression of Wnt7b, rather than Wnt1, Wnt7a and Wnt9a, may serve as a prognostic biomarker for breast cancer.

Opposite Roles of Wnt7a and Sfrp1 in Modulating Proper Development of Neural Progenitors in the Mouse Cerebral Cortex

The Wingless (Wnt)-mediated signals are involved in many important aspects of development of the mammalian cerebral cortex. How Wnts interact with their modulators in cortical development is still unclear. Here, we show that Wnt7a and secreted frizzled-related protein 1 (Sfrp1), a soluble modulator of Wnts, are co-expressed in mouse embryonic cortical neural progenitors (NPs). Knockout of Wnt7a in mice causes microcephaly due to reduced NP population and neurogenesis, and Sfrp1 has an opposing effect compared to Wnt7a. Similar to Dkk1, Sfrp1 decreases the Wnt1 and Wnt7a activity in vitro. Our results suggest that Wnt7a and Sfrp1 play opposite roles to ensure proper NP progeny in the developing cortex.

Niclosamide, an oral antihelmintic drug, exhibits antimetastatic activity in hepatocellular carcinoma cells through downregulating twist-mediated CD10 expression

Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world, especially, in eastern Asia, and its prognosis is poor once metastasis occurs. Niclosamide, a US Food and Drug Administration-approved antihelmintic drug, was shown to inhibit the growth of various cancers including HCC, but the effect of niclosamide on cell motility and the underlying mechanism have not yet been completely defined. The present study demonstrated that niclosamide, at 0-40 nM, concentration-dependently inhibited wound closure and the migratory/invasive capacities of human Huh7 and SK-Hep-1 HCC cells without exhibiting cytotoxicity. A protease array analysis showed that CD10 was dramatically downregulated in Huh7 cells after niclosamide treatment. Western blot and flow cytometric assays further demonstrated that CD10 expression was concentration-dependently downregulated in Huh7 and SK-Hep-1 cells after niclosamide treatment. Mechanistic investigations found that niclosamide suppressed Twist-mediated CD10 transactivation. Moreover, knockdown of CD10 expression by CD10 small interfering RNA in HCC cells suppressed cell migratory/invasive abilities and overexpression of CD10 relieved the migration inhibition induced by niclosamide. Taken together, our results indicated that niclosamide could be a potential agent for inhibiting metastasis of HCC, and CD10 is an important target of niclosamide for suppressing the motility of HCC cells.

Niclosamide, a Drug with Many (Re)purposes

Niclosamide is an anthelmintic drug that has been used for over 50 years mainly to treat tapeworm infections. However, with the increase in drug repurposing initiatives, niclosamide has emerged as a true hit in many screens against various diseases. Indeed, from being an anthelmintic drug, it has now shown potential in treating Parkinson's disease, diabetes, viral and microbial infections, as well as various cancers. Such diverse pharmacological activities are a result of niclosamide's ability to uncouple mitochondrial phosphorylation and modulate a selection of signaling pathways, such as Wnt/β-catenin, mTOR and JAK/STAT3, which are implicated in many diseases. In this highlight, we discuss the plethora of diseases that niclosamide has shown promise in treating.

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.

Wnt7a activates canonical Wnt signaling, promotes bladder cancer cell invasion, and is suppressed by miR-370-3p

Once urinary bladder cancer (UBC) develops into muscle-invasive bladder cancer, its mortality rate increases dramatically. However, the molecular mechanisms of UBC invasion and metastasis remain largely unknown. Herein, using 5637 UBC cells, we generated two sublines with low (5637 NMI) and high (5637 HMI) invasive capabilities. Mass spectrum analyses revealed that the Wnt family protein Wnt7a is more highly expressed in 5637 HMI cells than in 5637 NMI cells. We also found that increased Wnt7a expression is associated with UBC metastasis and predicted worse clinical outcome in UBC patients. Wnt7a depletion in 5637 HMI and T24 cells reduced UBC cell invasion and decreased levels of active β-catenin and its downstream target genes involved in the epithelial-to-mesenchymal transition (EMT) and extracellular matrix (ECM) degradation. Consistently, treating 5637 NMI and J82 cells with recombinant Wnt7a induced cell invasion, EMT, and expression of ECM degradation-associated genes. Moreover, TOP/FOPflash luciferase assays indicated that Wnt7a activated canonical β-catenin signaling in UBC cells, and increased Wnt7a expression was associated with nuclear β-catenin in UBC samples. Wnt7a ablation suppressed matrix metalloproteinase 10 (MMP10) expression, and Wnt7a overexpression increased MMP10 promoter activity through two TCF/LEF promoter sites, confirming that Wnt7a-mediated MMP10 activation is mediated by the canonical Wnt/β-catenin pathway. Of note, the microRNA miR-370-3p directly repressed Wnt7a expression and thereby suppressed UBC cell invasion, which was partially restored by Wnt7a overexpression. Our results have identified an miR-370-3p/Wnt7a axis that controls UBC invasion through canonical Wnt/β-catenin signaling, which may offer prognostic and therapeutic opportunities.

FGF1 induces resistance to chemotherapy in ovarian granulosa tumor cells through regulation of p53 mitochondrial localization

Ovarian cancer remains associated with a high mortality rate and relapse is too frequently seen after chemotherapeutic treatment of granulosa cell tumors (GCTs) or epithelial ovarian cancers (EOCs). It is thus of major importance to progress in the knowledge of the molecular mechanisms underlying chemoresistance of ovarian tumors. Overexpression of Fibroblast Growth Factor 1 (FGF1) is observed in various cancers, correlates with poor survival and could be responsible for resistance to platinum-based chemotherapy of serous ovarian cancers. How FGF1 promotes escape to chemotherapy remains unknown. In previous studies, we showed that FGF1 inhibits p53 transcriptional activities, leading to increased cell survival of neuronal or fibroblast cell lines. In this study, we show that FGF1 favors survival of COV434 cells upon treatment with etoposide and cisplatin, two common chemotherapeutic molecules used for ovarian cancer. Etoposide and cisplatin induced mitochondrial depolarization, cytochrome c release and caspase activation in COV434 cells. Overexpression of FGF1 counteracts these events and thus allows increased survival of ovarian cells. In this study, FGF1 had little effect on p53 stability and transcriptional activities. Etoposide induced p21 expression as expected, but p21 protein levels were even increased in the presence of FGF1. Using RNA interference, we showed that p21 exerts an anti-apoptotic activity in COV434 cells. However abrogating this activity was not sufficient to restore cell death of FGF1-overexpressing cells. We also show for the first time that p53 mitochondrial pathway is involved in the cell death of COV434 cells. Indeed, p53 accumulates at mitochondria upon etoposide treatment and inhibition of p53 mitochondrial localization using pifithrin-µ inhibits apoptosis of COV434 cells. FGF1 also decreases mitochondrial accumulation of p53 induced by etoposide. This constitutes a novel mechanism of action for FGF1 to promote cell survival in response to chemotherapy.

JAK2/STAT3 pathway as a therapeutic target in ovarian cancers

The activation of JAK2/STAT3 pathway has been reported to have critical roles in several solid tumors. The present study aimed to evaluate the correlation between JAK2/STAT3 activation and clinicopathological parameters in ovarian cancer types. Tissue microarrays made from the patients treated at the National Defense Medical College Hospital between 1984 and 2008 were evaluated using immunohistochemical (IHC) stainings. Medical charts of these patients including IHC results were retrospectively analyzed, and prognostic factors for progression-free survival and overall survival were evaluated. Among 341 enrolled patients, positive expression of p-STAT3 was observed in 95 cases (28%). Positive p-STAT3 was an independent worse prognostic factor for overall survival in all the cases. Additionally, p-STAT3 expression was related with overall survival in patients with clear-cell histology, but not in serous histology. The effect of an inhibitor of STAT3, niclosamide, was evaluated in ovarian clear-cell cancer cells, and niclosamide treatment decreased expression of p-STAT3, leading to increased apoptosis in a dose-dependent manner in vitro. The activation of JAK2/STAT3 pathway had significant impact on survival of ovarian cancers, especially for the cases with clear-cell histology. Although further analyses are needed, suppression of this pathway could be a candidate for the treatment of ovarian cancers.

Niclosamide sensitizes nasopharyngeal carcinoma to radiation by downregulating Ku70/80 expression

The aim of the present study was to investigate whether niclosamide could sensitize the nasopharyngeal carcinoma cells to radiation and further explore the underlying mechanisms. CCK-8 assay was used to determine the effect of niclosamide on the proliferation of NPC cells. Colony formation assay was used to evaluate the radiosensitizing effect of niclosamide on NPC cells. Flow cytometry analysis was used to determine the apoptosis of NPC cells induced by niclosamide. Immunofluorescent staining was used to detect the formation of γ-H2AX foci and the localization of Ku70/80 proteins in NPC cells. Real-time PCR quantification analysis was used to examine the level of Ku70/80 mRNA. DNA damage repair-related proteins were detected by western blot analysis. Our results showed that niclosamide markedly suppressed the proliferation of NPC cells. Niclosamide pretreatment followed by irradiation reduced the colony forming ability of NPC cells. Niclosamide in combination with irradiation significantly increased the apoptotic rate of NPC cells. Niclosamide significantly reduced the transcriptional level of K70/80 but not the translocation of Ku70/80 protein induced by irradiation. In conclusion, our study demonstrated that niclosamide could inhibit the growth of NPC cells and sensitize the NPC cells to radiation via suppressing the transcription of Ku70/80.

Therapeutic Effects of Punicalagin Against Ovarian Carcinoma Cells in Association With β-Catenin Signaling Inhibition

AIM

The aim of this study was to investigate the effects of punicalagin, a polyphenol isolated from Punica granatum, on human A2780 ovarian cancer cells in vitro.

METHODS

The viability of human A2780 ovarian cells was evaluated using Cell Counting Kit-8 assay. Cell cycle was detected with flow cytometry analysis. The protein expression levels of Bcl-2, Bax, β-catenin, cyclin D1, survivin, tissue inhibitor of metalloproteinase (TIMP)-2, and TIMP-3 were measured using Western blot analysis. Matrix metalloproteinase (MMP)-2 and MMP-9 activity was determined with gelatin zymography. Wound healing assay was used to determine cell migration.

RESULTS

Punicalagin inhibited the cell viability of A2780 cells in a dose- and time-dependent manner, and the cell cycle of A2780 cells was arrested in G1/S phase transition. The treatment also induced apoptosis as shown by the up-regulation of Bax and down-regulation of Bcl-2. On the other hand, punicalagin treatment increased the expressions of TIMP-2 and TIMP-3, decreased the activities of MMP-2 and MMP-9, and inhibited cell migration. In addition, the β-catenin pathway was suppressed as shown by the down-regulations of β-catenin and its downstream factors including cyclin D1 and survivin.

CONCLUSIONS

Punicalagin may have cancer-chemopreventive as well as cancer-chemotherapeutic effects against human ovarian cancer in humans through the inhibition of β-catenin signaling pathway.

Targeting of cell cycle and let-7a/STAT3 pathway by niclosamide inhibits proliferation, migration and invasion in oral squamous cell carcinoma cells

The low median survival rate of oral squamous cell carcinoma (OSCC) is associated with chemotherapeutic resistance. Niclosamide is an oral anti-helminthic drug, its anti-cancer effect has been reported in recent years. However, the effect of niclosamide on OSCC remains largely unknown. In this study, we, for the first time, investigated the underlying mechanisms from cell cycle arrest and let-7a/STAT3 axis through CCK-8, cell cycle, apoptosis, wound healing, Transwell invasion, generation of stable cell line, real-time PCR, and western blot assays using two OSCC cell lines WSU-HN6 and Tca83. We showed that niclosamide could inhibit OSCC cells proliferation through causing cell cycle arrest in G1 phase and promoting apoptosis, while the cell cycle-related proteins MCM2, MCM7, CDK2 and CDK4 were downregulated and the apoptosis-related proteins p53 and cleaved caspase-3 were upregulated. Furthermore, niclosamide could inhibit migration and invasion of OSCC through upregulation of let-7a expression and downregulation of p-STAT3 expression. What is more, we established the stably expressing let-7a cell line (HN6-let-7a). Like niclosamide, HN6-let-7a could decrease the ability of the cell migration, invasion as well as the expression of p-STAT3. Collectively, our study finds the new mechanisms that niclosamide inhibits OSCC proliferation through causing cell cycle arrest in G1 phase via downregulation of the above cell cycle-related genes; promotes OSCC apoptosis through upregulation of pro-apoptotic genes; decreases migration and invasion of OSCC by let-7a/STAT3 axis, thus providing a preferred therapeutic candidate for OSCC in future.

FGF1 protects neuroblastoma SH-SY5Y cells from p53-dependent apoptosis through an intracrine pathway regulated by FGF1 phosphorylation

Neuroblastoma, a sympathetic nervous system tumor, accounts for 15% of cancer deaths in children. In contrast to most human tumors, p53 is rarely mutated in human primary neuroblastoma, suggesting impaired p53 activation in neuroblastoma. Various studies have shown correlations between fgf1 expression levels and both prognosis severity and tumor chemoresistance. As we previously showed that fibroblast growth factor 1 (FGF1) inhibited p53-dependent apoptosis in neuron-like PC12 cells, we initiated the study of the interaction between the FGF1 and p53 pathways in neuroblastoma. We focused on the activity of either extracellular FGF1 by adding recombinant rFGF1 in media, or of intracellular FGF1 by overexpression in human SH-SY5Y and mouse N2a neuroblastoma cell lines. In both cell lines, the genotoxic drug etoposide induced a classical mitochondrial p53-dependent apoptosis. FGF1 was able to inhibit p53-dependent apoptosis upstream of mitochondrial events in SH-SY5Y cells by both extracellular and intracellular pathways. Both rFGF1 addition and etoposide treatment increased fgf1 expression in SH-SY5Y cells. Conversely, rFGF1 or overexpressed FGF1 had no effect on p53-dependent apoptosis and fgf1 expression in neuroblastoma N2a cells. Using different FGF1 mutants (that is, FGF1^K132E, FGF1^S130A and FGF1^S130D), we further showed that the C-terminal domain and phosphorylation of FGF1 regulate its intracrine anti-apoptotic activity in neuroblastoma SH-SY5Y cells. This study provides the first evidence for a role of an intracrine growth factor pathway on p53-dependent apoptosis in neuroblastoma, and could lead to the identification of key regulators involved in neuroblastoma tumor progression and chemoresistance.

Characterization of Lgr5+ Progenitor Cell Transcriptomes after Neomycin Injury in the Neonatal Mouse Cochlea

Lgr5+ supporting cells (SCs) are enriched hair cell (HC) progenitors in the cochlea. Both in vitro and in vivo studies have shown that HC injury can spontaneously activate Lgr5+ progenitors to regenerate HCs in the neonatal mouse cochlea. Promoting HC regeneration requires the understanding of the mechanism of HC regeneration, and this requires knowledge of the key genes involved in HC injury-induced self-repair responses that promote the proliferation and differentiation of Lgr5+ progenitors. Here, as expected, we found that neomycin-treated Lgr5+ progenitors (NLPs) had significantly greater HC regeneration ability, and greater but not significant proliferation ability compared to untreated Lgr5+ progenitors (ULPs) in response to neomycin exposure. Next, we used RNA-seq analysis to determine the differences in the gene-expression profiles between the transcriptomes of NLPs and ULPs from the neonatal mouse cochlea. We first analyzed the genes that were enriched and differentially expressed in NLPs and ULPs and then analyzed the cell cycle genes, the transcription factors, and the signaling pathway genes that might regulate the proliferation and differentiation of Lgr5+ progenitors. We found 9 cell cycle genes, 88 transcription factors, 8 microRNAs, and 16 cell-signaling pathway genes that were significantly upregulated or downregulated after neomycin injury in NLPs. Lastly, we constructed a protein-protein interaction network to show the interaction and connections of genes that are differentially expressed in NLPs and ULPs. This study has identified the genes that might regulate the proliferation and HC regeneration of Lgr5+ progenitors after neomycin injury, and investigations into the roles and mechanisms of these genes in the cochlea should be performed in the future to identify potential therapeutic targets for HC regeneration.

An integrated analysis identifies STAT4 as a key regulator of ovarian cancer metastasis

Epithelial ovarian cancer (EOC) is one of the most common gynecological cancers, with diagnosis often at a late stage. Metastasis is a major cause of death in patients with EOC, but the underlying molecular mechanisms remain obscure. Here, we utilized an integrated approach to find potential key transcription factors involved in ovarian cancer metastasis and identified STAT4 as a critical player in ovarian cancer metastasis. We found that activated STAT4 was overexpressed in epithelial cells of ovarian cancer and STAT4 overexpression was associated with poor outcome of ovarian cancer patients, which promoted metastasis of ovarian cancer in both in vivo and in vitro. Although STAT4 mediated EOC metastasis via inducing epithelial-to-mesenchymal transition (EMT) of ovarian cancer cells in vivo, STAT4 failed to induce EMT directly in vitro, suggesting that STAT4 might mediate EMT process via cancer-stroma interactions. Further functional analysis revealed that STAT4 overexpression induced normal omental fibroblasts and adipose- and bone marrow-derived mesenchymal stem cells to obtain cancer-associated fibroblasts (CAF)-like features via induction of tumor-derived Wnt7a. Reciprocally, increased production of CAF-induced CXCL12, IL6 and VEGFA within tumor microenvironment could enable peritoneal metastasis of ovarian cancer via induction of EMT program. In summary, our study established a model that STAT4 promotes ovarian cancer metastasis via tumor-derived Wnt7a-induced activation of CAFs.