Wnt5a suppresses colon cancer by inhibiting cell proliferation and epithelial-mesenchymal transition

Signaling pathways involved in colorectal cancer: pathogenesis and targeted therapy

Colorectal cancer (CRC) remains one of the leading causes of cancer-related mortality worldwide. Its complexity is influenced by various signal transduction networks that govern cellular proliferation, survival, differentiation, and apoptosis. The pathogenesis of CRC is a testament to the dysregulation of these signaling cascades, which culminates in the malignant transformation of colonic epithelium. This review aims to dissect the foundational signaling mechanisms implicated in CRC, to elucidate the generalized principles underpinning neoplastic evolution and progression. We discuss the molecular hallmarks of CRC, including the genomic, epigenomic and microbial features of CRC to highlight the role of signal transduction in the orchestration of the tumorigenic process. Concurrently, we review the advent of targeted and immune therapies in CRC, assessing their impact on the current clinical landscape. The development of these therapies has been informed by a deepening understanding of oncogenic signaling, leading to the identification of key nodes within these networks that can be exploited pharmacologically. Furthermore, we explore the potential of integrating AI to enhance the precision of therapeutic targeting and patient stratification, emphasizing their role in personalized medicine. In summary, our review captures the dynamic interplay between aberrant signaling in CRC pathogenesis and the concerted efforts to counteract these changes through targeted therapeutic strategies, ultimately aiming to pave the way for improved prognosis and personalized treatment modalities in colorectal cancer.

The evolving roles of Wnt signaling in stem cell proliferation and differentiation, the development of human diseases, and therapeutic opportunities

The evolutionarily conserved Wnt signaling pathway plays a central role in development and adult tissue homeostasis across species. Wnt proteins are secreted, lipid-modified signaling molecules that activate the canonical (β-catenin dependent) and non-canonical (β-catenin independent) Wnt signaling pathways. Cellular behaviors such as proliferation, differentiation, maturation, and proper body-axis specification are carried out by the canonical pathway, which is the best characterized of the known Wnt signaling paths. Wnt signaling has emerged as an important factor in stem cell biology and is known to affect the self-renewal of stem cells in various tissues. This includes but is not limited to embryonic, hematopoietic, mesenchymal, gut, neural, and epidermal stem cells. Wnt signaling has also been implicated in tumor cells that exhibit stem cell-like properties. Wnt signaling is crucial for bone formation and presents a potential target for the development of therapeutics for bone disorders. Not surprisingly, aberrant Wnt signaling is also associated with a wide variety of diseases, including cancer. Mutations of Wnt pathway members in cancer can lead to unchecked cell proliferation, epithelial-mesenchymal transition, and metastasis. Altogether, advances in the understanding of dysregulated Wnt signaling in disease have paved the way for the development of novel therapeutics that target components of the Wnt pathway. Beginning with a brief overview of the mechanisms of canonical and non-canonical Wnt, this review aims to summarize the current knowledge of Wnt signaling in stem cells, aberrations to the Wnt pathway associated with diseases, and novel therapeutics targeting the Wnt pathway in preclinical and clinical studies.

Unraveling a novel hippo-associated immunological prognostic signature: The contribution of SERPINE1 in facilitating colorectal cancer progression via the notch signaling pathway

BACKGROUND

Accumulating evidence demonstrated that Hippo signaling pathway is implicated in tumor initiation and progression. However, there have been limited studies on establishing signatures utilizing genes related to the Hippo pathway to evaluate prognosis and clinical efficacy in colorectal cancer (CRC) patients.

METHODS

Hippo pathway-associated genes with prognostic significance were identified in the TCGA database. Subsequently, a prognostic signature associated with the Hippo pathway was constructed using Cox and LASSO regression analyses. Survival analysis, ROC analysis, and stratified analyses were conducted to appraise the performance effect of our prognostic model. We also explored the relationship between the risk score and tumor immune microenvironment. Furthermore, GO analyses and GSEA were performed for SERPINE1. Additional experiments were conducted to illuminate the underlying function and possible mechanism of SERPINE1 in CRC cell proliferation and migration.

RESULTS

We identified 58 differentially expressed genes associated with Hippo pathway that have prognostic significance in CRC. Among them, five genes (PPP2CB, SERPINE1, WNT5A, TCF7L1, and LEF1) were selected to establish a prognostic signature for CRC. Multivariate analysis demonstrated that this signature exhibited excellent diagnostic and prognostic performance, providing maximum benefits for CRC patients. In accordance with the prognostic signatures, the cases were divided into low-risk and high-risk groups. Remarkably, the high-risk group displayed lower immune scores, reduced immune cell infiltration, and decreased expression of immune checkpoints. Low-risk group could more possibly benefit from conventional chemotherapeutic and targeted therapies. CRC exhibited significantly elevated expression of SERPINE1, which was linked to worst overall survival. Moreover, inhibition of SERPINE1 suppressed proliferation, invasion, and migration of CRC cells via Notch pathway.

CONCLUSIONS

To sum up, we established a novel immunological prognostic signature utilizing genes associated with the Hippo pathway. This signature offers accurate prognostic prediction and can guide individualized therapy for patients with CRC.

Aberrant expression of UBE2C in endometrial cancer and its correlation to epithelial mesenchymal transition

Ubiquitin-conjugating enzyme E2C (UBE2C), its overexpression promotes tumor progression, is a key component of the ubiquitin conjugating proteasome complex. Epithelial-mesenchymal transition, which is lost epithelial features and gained mesenchymal features in some epithelial cancers, is involved in epithelial cancers' invasiveness and metastasis. The aim of this study is to detect the expression of UBE2C, WNT5α, and E-cad in endometrial cancer (EC) and their clinical significance. The expression of UBE2C, WNT5α, and ZEB1 in 125 cases EC tissues were detected by immunohistochemistry. Patients clinicopathological, demography, and follow-up data were also collected. Positive rates of expression of UBE2C and ZEB1 were significantly higher in EC tissues when compared with the control tissues. The positive expression of UBE2C and ZEB1 were positively associated with tumor stages, local lymph node metastasis, and International Federation of Gynecology and Obstetrics (FIGO) stages. The positive rate of expression of WNT5a was significantly lower in EC tissues when compared with the control tissues. And positive expression of E-cad was inversely related to tumor stages, lymph node metastasis stages, and FIGO stages. Kaplan-Meier analyses demonstrated that positive expression of UBE2C or ZEB1 for EC patients had unfavorably overall survival time when compared with patients with negative expression of UBE2C or ZEB1. And EC patients with positive expression of WNT5a had favorably overall survival time when compared with EC patients with negative expression of WNT5a. Multivariate analysis demonstrated that positive expression UBE2C, WNT5α, and ZEB1, as well as FIGO stages were independent prognostic factors for EC patients. UBE2C, ZEB1, and WNT5a should be considered promising biomarkers for EC patients' prognosis.

The Roles of Secreted Wnt Ligands in Cancer

Wnt ligands are secreted signaling proteins that display a wide range of biological effects. They play key roles in stimulating Wnt signaling pathways to facilitate processes such as tissue homeostasis and regeneration. Dysregulation of Wnt signaling is a hallmark of many cancers and genetic alterations in various Wnt signaling components, which result in ligand-independent or ligand-dependent hyperactivation of the pathway that have been identified. Recently, research is focusing on the impact of Wnt signaling on the interaction between tumor cells and their micro-environment. This Wnt-mediated crosstalk can act either in a tumor promoting or suppressing fashion. In this review, we comprehensively outline the function of Wnt ligands in different tumor entities and their impact on key phenotypes, including cancer stemness, drug resistance, metastasis, and immune evasion. Lastly, we elaborate approaches to target Wnt ligands in cancer therapy.

Advances of Wnt Signalling Pathway in Colorectal Cancer

Colorectal cancer (CRC) represents one of the most common cancers worldwide, with a high mortality rate despite the decreasing incidence and new diagnostic and therapeutic strategies. CRC arises from both epidemiologic and molecular backgrounds. In addition to hereditary factor and genetic mutations, the strongly varying incidence of CRC is closely linked to chronic inflammatory disorders of the intestine and terrible dietary habits. The Wnt signalling pathway is a complex regulatory network that is implicated in many CRC physiological processes, including cancer occurrence, development, prognosis, invasion, and metastasis. It is currently believed to include classical Wnt/β-catenin, Wnt/PCP, and Wnt/Ca²⁺. In this review, we summarise the recent mechanisms and potential regulators of the three branches of the Wnt signalling pathway in CRC.

Integrated analysis of necroptosis-related genes for evaluating immune infiltration and colon cancer prognosis

Background

Colon cancer (CC) is the second most common gastrointestinal malignancy. About one in five patients have already developed distant metastases at the time of initial diagnosis, and up to half of patients develop distant metastases from initial local disease, which leads to a poor prognosis for CC patients. Necroptosis plays a key role in promoting tumor growth in different tumors. The purpose of this study was to construct a prognostic model composed of necroptosis-related genes (NRGs) in CC.

Methods

The Cancer Genome Atlas was used to obtain information on clinical features and gene expression. Gene expression differential analysis, weighted gene co-expression network analysis, univariate Cox regression analysis and the least absolute shrinkage and selection operator regression algorithm were utilized to identify prognostic NRGs. Thereafter, a risk scoring model was established based on the NRGs. Biological processes and pathways were identified by gene ontology and gene set enrichment analysis (GSEA). Further, protein-protein interaction and ceRNA networks were constructed based on mRNA-miRNA-lncRNA. Finally, the effect of necroptosis related risk score on different degrees of immune cell infiltration was evaluated.

Results

CALB1, CHST13, and SLC4A4 were identified as NRGs of prognostic significance and were used to establish a risk scoring model. The time-dependent receiver operating characteristic curve analysis revealed that the model could well predict the 1-, 3-, and 5-year overall survival (OS). Further, GSEA suggested that the NRGs may participate in biological processes, such as the WNT pathway and JAK-Stat pathway. Eight key hub genes were identified, and a ceRNA regulatory network, which comprised 1 lncRNA, 5 miRNAs and 3 mRNAs, was constructed. Immune infiltration analysis revealed that the low-risk group had significantly higher immune-related scores than the high-risk group. A nomogram of the model was constructed based on the risk score, necroptosis, and the clinicopathological features (age and TNM stage). The calibration curves implied that the model was effective at predicting the 1-, 3-, and 5-year OS of CC.

Conclusion

Our NRG-based prognostic model can assist in the evaluation of CC prognosis and the identification of therapeutic targets for CC.

SEL1L-HRD1 ER-associated degradation suppresses hepatocyte hyperproliferation and liver cancer

Endoplasmic reticulum (ER) homeostasis has been implicated in the pathogenesis of various forms of cancer; however, our understanding of the role of ER quality control mechanisms in tumorigenesis remains incomplete. Here, we show that the SEL1L-HRD1 complex of ER-associated degradation (ERAD) suppresses hepatocyte proliferation and tumorigenesis in mice. Hepatocyte-specific deletion of Sel1L or Hrd1 predisposed mice to diet/chemical-induced tumors. Proteomics screen from SEL1L-deficient livers revealed WNT5A, a tumor suppressor, as an ERAD substrate. Indeed, nascent WNT5A was misfolding prone and degraded by SEL1L-HRD1 ERAD in a quality control capacity. In the absence of ERAD, WNT5A misfolds is largely retained in the ER and forms high-molecular weight aggregates, thereby depicting a loss-of-function effect and attenuating WNT5A-mediated suppression of hepatocyte proliferation. In humans, SEL1L-HRD1 ERAD expression correlated positively with survival time for patients with liver cancer. Overall, our data reveal a key role of SEL1L-HRD1 ERAD in suppressing hepatocyte proliferation and liver cancer.

WNT5A in tumor development and progression: A comprehensive review

The investigation of tumor microenvironment (TME) is essential to better characterize the complex cellular crosstalk and to identify important immunological phenotypes and biomarkers. The niche is a crucial contributor to neoplasm initiation, maintenance and progression. Therefore, a deeper analysis of tumor surroundings could improve cancer diagnosis, prognosis and assertive treatment. Thus, the WNT family exerts a critical action in tumorigenesis of different types of neoplasms due to dysregulations in the TME. WNT5A, an evolutionary WNT member, is involved in several cellular and physiopathological processes, in addition to tissue homeostasis. The WNT5A protein exerts paradoxical effects while acting as both an oncogene or tumor suppressor by regulating several non-canonical signaling pathways, and consequently interfering in cell growth, cytoskeletal remodeling, migration and invasiveness. This review focuses on a thorough characterization of the role of WNT5A in neoplastic transformation and progression, which may help to understand the prognostic potentiality of WNT5A and its features as a therapeutic target in several cancers. Additionally, we herein summarized novel findings on the mechanisms by which WNT5A might favor tumorigenesis or suppression of cancer progression and discussed the recently developed treatment strategies using WNT5A as a protagonist.

Tumor suppressive functions of WNT5A in rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a highly aggressive soft tissue malignancy that predominantly affects children. The main subtypes are alveolar RMS (ARMS) and embryonal RMS (ERMS) and the two show an impaired muscle differentiation phenotype. One pathway involved in muscle differentiation is WNT signaling. However, the role of this pathway in RMS is far from clear. Our recent data showed that the canonical WNT/β-Catenin pathway serves a subordinate role in RMS, whereas non-canonical WNT signaling probably is more important for this tumor entity. The present study investigated the role of WNT5A, which is the major ligand of non-canonical WNT signaling, in ERMS and ARMS. Gene expression analysis showed that WNT5A was expressed in human RMS samples and that its expression is more pronounced in ERMS. When stably overexpressed in RMS cell lines, WNT5A decreased proliferation and migration of the cells as demonstrated by BrdU incorporation and Transwell migration or scratch assay, respectively. WNT5A also decreased the self-renewal capacity and the expression of stem cell markers and modulates the levels of muscle differentiation markers as shown by sphere assay and western blot analysis, respectively. Finally, overexpression of WNT5A can destabilize active β-Catenin of RMS cells. A WNT5A knockdown has opposite effects. Together, the results suggest that WNT5A has tumor suppressive functions in RMS, which accompanies downregulation of β-Catenin.

WNT5A promotes the metastasis of esophageal squamous cell carcinoma by activating the HDAC7/SNAIL signaling pathway

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers worldwide, with high incidence and mortality rates and low survival rates. However, the detailed molecular mechanism of ESCC progression remains unclear. Here, we first showed significantly higher WNT5A and SNAIL expression in ESCC samples than in corresponding paracancerous samples. High WNT5A and SNAIL expression levels correlated positively with lymphatic metastasis and poor prognosis for patients with ESCC based on immunohistochemical (IHC) staining of 145 paired ESCC samples. Spearman's correlation analyses confirmed the strong positive correlation between WNT5A and SNAIL expression, and patients with ESCC presenting coexpression of WNT5A and SNAIL had the worst prognosis. Then, we verified that the upregulation of WNT5A promoted ESCC cell metastasis in vivo and in vitro, suggesting that WNT5A might be a promising therapeutic target for the prevention of ESCC. Furthermore, WNT5A overexpression induced the epithelial-mesenchymal transition via histone deacetylase 7 (HDAC7) upregulation, and HDAC7 silencing significantly reversed WNT5A-induced SNAIL upregulation and ESCC cell metastasis. In addition, we used HDAC7 inhibitors (SAHA and TMP269) to further confirm that HDAC7 participates in WNT5A-mediated carcinogenesis. Based on these results, HDAC7 is involved in WNT5A-mediated ESCC progression, and approaches targeting WNT5A and HDAC7 might be potential therapeutic strategies for ESCC.

Nucleic acid-based markers of response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer

The progress that has been made in the treatment of rectal cancer has mostly resulted from multimodality strategy approach that combines surgery, chemotherapy and radiotherapy. In locally advanced rectal cancer (LARC), surgery remains the primary treatment, while neoadjuvant chemoradiotherapy (nCRT) is used to downsize or downstage the tumor before surgical resection. Highly variable response to nCRT observed in LARC patients raises the need for biomarkers to enable prediction and evaluation of treatment response in a more efficient and timely manner than currently available tools. The search for predictive biomarkers continues beyond blood proteins, which have failed in subsequent validation studies. This review presents nucleic acids-based markers and their predictive potential in LARC patients. Most of the candidate biomarkers come from relatively small single-institution studies. The only candidate biomarker that emerged as relevant in more than a single study was elevated levels of Fusobacterium nucleatum nucleic acids in tumor tissue. Considering that this marker is easily accessible through non-invasive analysis of faecal samples, its predictive potential is worth further validation. The other candidate nucleic acid-based biomarkers require more consistent studies on larger cohorts before they can be considered for use in clinical setting.

Identification of Circular RNA-Based Immunomodulatory Networks in Colorectal Cancer

BACKGROUND

Circular RNAs (circRNAs) have been recently proposed as hub molecules in various diseases, especially in tumours. We found that circRNAs derived from ribonuclease P RNA component H1 (RPPH1) were highly expressed in colorectal cancer (CRC) samples from Gene Expression Omnibus (GEO) datasets.

OBJECTIVE

We sought to identify new circRNAs derived from RPPH1 and investigate their regulation of the competing endogenous RNA (ceRNA) and RNA binding protein (RBP) networks of CRC immune infiltration.

METHODS

The circRNA expression profiles miRNA and mRNA data were extracted from the GEO and The Cancer Genome Atlas (TCGA) datasets, respectively. The differentially expressed (DE) RNAs were identified using R software and online server tools, and the circRNA-miRNA-mRNA and circRNA-protein networks were constructed using Cytoscape. The relationship between targeted genes and immune infiltration was identified using the GEPIA2 and TIMER2 online server tools.

RESULTS

A ceRNA network, including eight circRNAs, five miRNAs, and six mRNAs, was revealed. Moreover, a circRNA-protein network, including eight circRNAs and 49 proteins, was established. The targeted genes, ENOX1, NCAM1, SAMD4A, and ZC3H10, are closely related to CRC tumour-infiltrating macrophages.

CONCLUSIONS

We analysed the characteristics of circRNA from RPPH1 as competing for endogenous RNA binding miRNA or protein in CRC macrophage infiltration. The results point towards the development of a new diagnostic and therapeutic paradigm for CRC.

Clinical Importance of Wnt5a in the Pathogenesis of Colorectal Cancer

Wnt5a is one of the potent signaling molecules that initiates responses involved in cancer through activation of both canonical and noncanonical signaling cascades. Wnt5a both directly and indirectly triggers cancer-associated signaling pathways based on the cancer type. In colorectal cancer (CRC), altering Wnt5a expression can influence several cellular processes of tumor cells, including proliferation, differentiation, migration, invasion, and metastasis. This review summarizes the molecular mechanisms and clinical importance of Wnt5a in the pathogenesis of CRC for better understanding the pathogenesis and its potential role as a prognostic marker and as an appropriate therapeutic target in the treatment of this disease in the future.

WNT5B in Physiology and Disease

WNT5B, a member of the WNT family of proteins that is closely related to WNT5A, is required for cell migration, cell proliferation, or cell differentiation in many cell types. WNT5B signals through the non-canonical β-catenin-independent signaling pathway and often functions as an antagonist of canonical WNT signaling. Although WNT5B has a high amino acid identity with WNT5A and is often assumed to have similar activities, WNT5B often exhibits unique expression patterns and functions. Here, we describe the distinct effects and mechanisms of WNT5B on development, bone, adipose tissue, cardiac tissue, the nervous system, the mammary gland, the lung and hematopoietic cells, compared to WNT5A. We also highlight aberrances in non-canonical WNT5B signaling contributing to diseases such as osteoarthritis, osteoporosis, obesity, type 2 diabetes mellitus, neuropathology, and chronic diseases associated with aging, as well as various cancers.

WNT5a in Colorectal Cancer: Research Progress and Challenges

Despite the clinical development of new adjuvant and neoadjuvant chemotherapy drugs, colorectal cancer is still one of the leading causes of cancer-related death in human beings. WNT5a, an autocrine and paracrine β-catenin independent ligand, has been shown to induce tumor inhibition and carcinogenic signals, depending on the type of cancer. In patients with colorectal cancer, WNT5a triggers a variety of downstream signaling pathways, which mainly affect the migration and invasion of tumor cells. This article reviews the mechanism and therapeutic potential of WNT5a in colorectal cancer. In short, an in-depth understanding of the role of WNT5a in colorectal cancer is very helpful to better deal with this disease.

Wnt5A modulates integrin expression in a receptor-dependent manner in ovarian cancer cells

Wnt5A signals through various receptors that confer versatile biological functions. Here, we used Wnt5A overexpressing human ovarian SKOV-3 and OVCAR-3 stable clones for assessing integrin expression, cell proliferation, migration, invasion, and the ability of multicellular aggregates (MCAs) formation. We found here, that Wnt5A regulates differently the expression of its receptors in the stable Wnt5A overexpressing clones. The expression levels of Frizzled (FZD)-2 and -5, were increased in different clones. However ROR-1, -2 expression levels were differently regulated in clones. Wnt5A overexpressing clones showed increased cell proliferation, migration, and clonogenicity. Moreover, Wnt5A overexpressing SKOV-3 clone showed increased MCAs formation ability. Cell invasion had been increased in OVCAR-3-derived clones, while this was decreased in SKOV-3-derived clone. Importantly, αv integrin expression levels were increased in all assessed clones, accompanied by increased cell attachment to fibronectin and focal adhesion kinase activity. Moreover, the treatment of clones with Box5 as a Wnt5A/FZD5 antagonist abrogates ITGAV increase, cell proliferation, migration, and their attachment to fibronectin. Accordingly, we observed significantly higher expression levels of ITGAV and ITGB3 in human high-grade serous ovarian cancer specimens and ITGAV correlated positively with Wnt5A in metastatic serous type ovarian cancer. In summary, we hypothesize here, that Wnt5A/FZD-5 signaling modulate αv integrin expression levels that could be associated with ovarian cancer cell proliferation, migration, and fibronectin attachment.

The emerging role of Wnt5a in the promotion of a pro-inflammatory and immunosuppressive tumor microenvironment

Wnt5a is the prototypical activator of the non-canonical Wnt pathways, and its overexpression has been implicated in the progression of several tumor types by promoting cell motility, invasion, EMT, and metastasis. Recent evidences have revealed a novel role of Wnt5a in the phosphorylation of the NF-κB subunit p65 and the activation of the NF-κB pathway in cancer cells. In this article, we review the molecular mechanisms and mediators defining a Wnt5a/NF-κB signaling pathway and propose that the aberrant expression of Wnt5a in some tumors drives a Wnt5a/NF-κB/IL-6/STAT3 positive feedback loop that amplifies the effects of Wnt5a. The evidences discussed here suggest that Wnt5a has a double effect on the tumor microenvironment. First, it activates an autocrine ROR1/Akt/p65 pathway that promotes inflammation and chemotaxis of immune cells. Then, Wnt5a activates a TLR/MyD88/p50 pathway exclusively in myelomonocytic cells promoting the synthesis of the anti-inflammatory cytokine IL-10 and a tolerogenic phenotype. As a result of these mechanisms, Wnt5a plays a negative role on immune cell function that contributes to an immunosuppressive tumor microenvironment and would contribute to resistance to immunotherapy. Finally, we summarized the development of different strategies targeting either Wnt5a or the Wnt5a receptor ROR1 that can be helpful for cancer therapy by contributing to generate a more immunostimulatory tumor microenvironment.

An Overview of Potential Therapeutic Agents Targeting WNT/PCP Signaling

Since the discovery of the proto-oncogene Wnt1 (Int1) in 1982, WNT signaling has been identified as one of the most important pathways that regulates a wide range of fundamental developmental and physiological processes in multicellular organisms. The canonical WNT signaling pathway depends on the stabilization and translocation of β-catenin and plays important roles in development and homeostasis. The WNT/planar cell polarity (WNT/PCP) signaling, also known as one of the β-catenin-independent WNT pathways, conveys directional information to coordinate polarized cell behaviors. Similar to WNT/β-catenin signaling, disruption or aberrant activation of WNT/PCP signaling also underlies a variety of developmental defects and cancers. However, the pharmacological targeting of WNT/PCP signaling for therapeutic purposes remains largely unexplored. In this review, we briefly discuss WNT/PCP signaling in development and disease and summarize the known drugs/inhibitors targeting this pathway.

miR‑576‑5p promotes epithelial‑to‑mesenchymal transition in colorectal cancer by targeting the Wnt5a‑mediated Wnt/β‑catenin signaling pathway

Colorectal cancer (CRC) is one of the most common types of malignancy and the third most commonly diagnosed form of cancer worldwide, ranking as the fourth leading cause of cancer‑associated mortality. MicroRNA (miR)‑576‑5p has been reported to be highly expressed in patients with CRC; however, its biological role remains unclear. The present study aimed therefore to investigate the biological role and underlying mechanism of miR‑576‑5p in CRC cell line SW480. The viability of SW480 cells following transfection with miR‑576‑5p mimic or inhibitor was analyzed using MTT assay. Wound healing and Transwell assays were performed to determine the cell migratory and invasive abilities, respectively. A dual luciferase reporter assay was used to verify the predicted binding site between miR‑576‑5p and Wnt5a. Reverse transcription‑quantitative PCR and western blotting were used to analyze the expression levels of miR‑576‑5p, E‑cadherin, N‑cadherin, vimentin, Snail1, Wnt5a, β‑catenin, c‑myc, cyclin D1 and p/t‑c‑Jun. Using bioinformatics analysis, high expression of miR‑576‑5p was found not only in tumor tissues, compared with the normal tissue, but also in CRC cells, compared with NCM460 cells. Furthermore, the inhibition of miR‑576‑5p expression significantly decreased the cell viability and the migratory and invasive abilities of SW480 cells, and suppressed the epithelial‑to‑mesenchymal transition (EMT). In addition, miR‑576‑5p could interact with Wnt5a and regulate the expression level of Wnt5a in order to influence the activity of Wnt/β‑catenin signaling. The results from rescue experiments further demonstrated that the effect of miR‑576‑5p overexpression on cell metastasis and EMT was reversed by Wnt5a overexpression or treatment with XAV‑939, which is an inhibitor of the Wnt/β‑catenin signaling pathway. In conclusion, the findings from the present study suggested that inhibition of miR‑576‑5p may suppress SW480 cell metastasis and EMT by targeting Wnt5a and regulating the Wnt5a‑mediated Wnt/β‑catenin signaling pathway, providing a potential therapeutic target for the treatment of CRC.

Role of Wnt5a in suppressing invasiveness of hepatocellular carcinoma via epithelial-mesenchymal transition

Inappropriate activation of the canonical Wnt signaling pathway is associated with progression of hepatocellular carcinoma (HCC). However, the association between the non-canonical pathway activated by Wnt5a and HCC is not well known. The present study investigated the significance of Wnt5a expression in HCC. Immunohistochemical staining of Wnt5a was performed on specimens from 243 patients who underwent hepatic resection for HCC. The present study investigated whether Wnt5a expression was associated with clinical and pathological factors and prognosis. Wnt5a expression in human HCC cell lines was investigated using western blotting. The effects of overexpression or knockdown of Wnt5a were evaluated using proliferation and invasion assays. Changes in epithelial-mesenchymal transition (EMT)-related molecules were investigated using western blotting. Wnt5a negativity was significantly associated with poor tumor differentiation and positive vascular invasion. In univariate analysis, Wnt5a negativity was identified as a significant prognostic factor for overall survival (OS). Multivariate analysis of OS demonstrated that Wnt5a negativity was an independent prognostic factor. Wnt5a expression was lower in HLE and HLF cells than in HepG2 and Huh7 cells. Knockdown of Wnt5a by short hairpin RNA transfection increased the proliferation and invasiveness of Huh7 cells, and decreased the expression levels of E-cadherin. In HLF cells, overexpression of Wnt5a inhibited invasiveness and decreased the expression levels of vimentin. Wnt5a negativity was associated with poor tumor differentiation and positive vascular invasion, and was an independent poor prognostic factor in patients with HCC. Wnt5a may be a tumor suppressor involved in EMT-mediated changes in invasiveness.

Osteoglycin silencing exerts inhibitory effects on myocardial fibrosis and epithelial/endothelial-mesenchymal transformation in a mouse model of myocarditis

Osteoglycin (Ogn), a class III SLRP member with multiple glycosylation sites, has been proposed to be engaged in cardiac dysfunction and adverse remodeling in human heart failure following myocardial infarction. However, the underlying mechanism remains to be elucidated. Thus, we sought to define the role of Ogn in regulation of the Wnt pathway on myocardial fibrosis and epithelial/endothelial-mesenchymal transformation (EMT/EndMT) in mice with myocarditis. The pathological changes are observed, while hematoxylin-eosin staining and picric acid Sirius red staining were conducted in successfully constructed myocarditis mouse models. Immunohistochemistry and enzyme-linked immunosorbent assay were adopted to determine Ogn and β-catenin levels and serum procollagen propeptide concentrations in the mouse myocardial tissues, respectively. Expression of Ogn and Wnt signaling pathway-related factors were measured by reverse transcription quantitative polymerase chain reaction and western blot assay, cell viability by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and cell cycle distribution and apoptosis by flow cytometry. We saw indicative pathological changes accompanied by many Ogn and β-catenin positive cells and increased serum procollagen propeptide, in the mouse myocardial tissues. Loss function assays showed reduced levels of Ogn, β-catenin, LRP6, TGF-β1, Twist, FSP-1, α-SMA and higher levels of E-cadherin and VE-cadherin, together with decreased proliferation rate, as well as increased apoptosis rate, indicating that the Wnt signaling pathway, proliferation were inhibited while apoptosis was enhanced with upon gene silencing. Coherently, depletion of Ogn inhibits myocardial fibroblasts proliferation and EMT/EndMT while facilitating myocardial fibroblasts apoptosis in myocarditis through the Wnt signaling pathway, thus serving as an intervention target for the molecular treatment of myocarditis.

RBBP4 promotes colon cancer malignant progression via regulating Wnt/β-catenin pathway

BACKGROUND

Our previous study demonstrated that RBBP4 was upregulated in colon cancer and correlated with poor prognosis of colon cancer and hepatic metastasis. However, the potential biological function of RBBP4 in colon cancer is still unknown.

AIM

To investigate the biological role and the potential mechanisms of RBBP4 in colon cancer progression.

METHODS

Real-time polymerase chain reaction and western blot analysis were used to detect the expression of RBBP4 in colon cancer cell lines. The cell proliferation and viability of SW620 and HCT116 cells with RBBP4 knockdown was detected by Cell Counting Kit-8 and 5-ethynyl-2’-deoxyuridine staining. The transwell assay was used to detect the invasion and migration capabilities of colon cancer cells with RBBP4 knockdown. Flow cytometry apoptosis assay was used to detect the apoptosis of colon cancer cells. Western blotting analysis was used to detect the expression of epithelial-mesenchymal transition and apoptosis related markers in colon cancer. The nuclear translocation of β-catenin was examined by Western blotting analysis in colon cancer cells with RBBP4 knockdown. The TOPFlash luciferase assay was used to detect the effect of RBBP4 on Wnt/β-catenin activation. The rescue experiments were performed in colon cancer cells treated with Wnt/β-catenin activator LiCl and RBBP4 knockdown.

RESULTS

We found that RBBP4 was highly expressed in colon cancer cell lines. The 5-ethynyl-2’-deoxyuridine assay showed that knockdown of RBBP4 significantly inhibited cell proliferation. RBBP4 inhibition reduced cell invasion and migration via regulating proteins related to epithelial-mesenchymal transition. Knockdown of RBBP4 significantly inhibited survivin-mediated apoptosis. Mechanistically, the TOPFlash assay showed that RBBP4 knockdown increased activity of the Wnt/β-catenin pathway. Meanwhile, RBBP4 knockdown suppressed nuclear translocation of β-catenin. With Wnt/β-catenin activator, rescue experiments suggested that the role of RBBP4 in colon cancer progression was dependent on Wnt/β-catenin pathway.

CONCLUSION

RBBP4 promotes colon cancer development via increasing activity of the Wnt/β-catenin pathway. RBBP4 may serve as a novel therapeutic target in colon cancer.

Ectopic expression of ROR1 prevents cochlear hair cell loss in guinea pigs with noise-induced hearing loss

Noise-induced hearing loss (NIHL) is one of the most frequent disabilities in industrialized countries. Evidence shows that hair cell loss in the auditory end organ is responsible for the majority of various ear pathological conditions. The functional roles of the receptor tyrosine kinase ROR1 have been underscored in various tumours. In this study, we evaluated the ability of ROR1 to influence cochlear hair cell loss of guinea pigs with NIHL. The NIHL model was developed in guinea pigs, with subsequent measurement of the auditory brainstem response (ABR). Gain-of-function experiments were employed to explore the role of ROR1 in NIHL. The interaction between ROR1 and Wnt5a and their functions in the cochlear hair cell loss were further analysed in response to alteration of ROR1 and Wnt5a. Guinea pigs with NIHL demonstrated elevated ABR threshold and down-regulated ROR1, Wnt5a and NF-κB p65. The up-regulation of ROR1 was shown to decrease the cochlear hair cell loss and the expression of pro-apoptotic gene (Bax, p53) in guinea pig cochlea, but promoted the expression of anti-apoptotic gene (Bcl-2) and the fluorescence intensity of cleaved-caspase-3. ROR1 interacted with Wnt5a to activate the NF-κB signalling pathway through inducing phosphorylation and translocation of p65. Furthermore, Wnt5a overexpression decreased the cochlear hair cell loss. Collectively, this study suggested the protection of overexpression of ROR1 against cochlear hair cell loss in guinea pigs with NIHL via the Wnt5a-dependent NF-κB signalling pathway.

Non-canonical WNT5a regulates Epithelial-to-Mesenchymal Transition in the mouse ovarian surface epithelium

The ovarian surface epithelium (OSE) is a monolayer that covers the ovarian surface and is involved in ovulation by rupturing and enabling release of a mature oocyte and by repairing the wound after ovulation. Epithelial-to-mesenchymal transition (EMT) is a mechanism that may promote wound healing after ovulation. While this process is poorly understood in the OSE, in other tissues wound repair is known to be under the control of the local microenvironment and different growth factors such as the WNT signaling pathway. Among WNT family members, WNT4 and WNT5a are expressed in the OSE and are critical for the ovulatory process. The objective of this study was to determine the potential roles of WNT4 and WNT5a in regulating the OSE layer. Using primary cultures of mouse OSE cells, we found WNT5a, but not WNT4, promotes EMT through a non-canonical Ca2+-dependent pathway, up-regulating the expression of Vimentin and CD44, enhancing cell migration, and inhibiting the CTNNB1 pathway and proliferation. We conclude that WNT5a is a stimulator of the EMT in OSE cells, and acts by suppressing canonical WNT signaling activity and inducing the non-canonical Ca2+ pathway.

Wnt5a-induced M2 polarization of tumor-associated macrophages via IL-10 promotes colorectal cancer progression

Background

Tumor-associated macrophages (TAMs) in the tumor microenvironment influence tumor initiation, invasion and metastasis. Several studies have shown that Wnt5a is mainly expressed in the tumor stroma, especially in TAMs. However, whether Wnt5a regulates the polarization and biological function of TAMs in colorectal cancer (CRC) is incompletely understood.

Methods

Immunofluorescence staining was performed to detect CD68 and Wnt5a expression in colorectal tissues from patients (63 CRC specimens VS 20 normal tissues). RT-qPCR, flow cytometry, ELISA and inhibitors were carried out to explore the role of Wnt5a in the polarization of TAMs. Clone formation and transwell assays were performed to determine the effects of Wnt5a–treated macrophages on tumor proliferation, migration and invasion in vitro. Finally, a xenograft model was applied to confirm the effects of Wnt5a⁺ TAMs on CRC tumorigenesis.

Results

We found that high Wnt5a⁺CD68⁺/CD68⁺ TAMs ratio was significantly associated with poor prognosis in CRC patients and Wnt5a⁺ TAM was an M2-like TAM subtype. Subsequently, we found that Wnt5a induced macrophages to secrete IL-10, which then acted as an autocrine cytokine to induce M2 polarization of these macrophages. IL-10 neutralizing antibody completely reversed the pro-M2 effect of Wnt5a. Mechanistically, the CaKMII-ERK1/2-STAT3 pathway was required for Wnt5a-mediated IL-10 expression in macrophages. Furthermore, Wnt5a-induced M2 macrophages promoted CRC cells proliferation, migration and invasion; knockdown of Wnt5a in TAMs significantly impaired the pro-tumor functions of TAMs.

Conclusions

Our data indicate that Wnt5a could induce M2 polarization of TAMs by regulating CaKMII-ERK1/2-STAT3 pathway–mediated IL-10 secretion, ultimately promoting tumor growth and metastasis of CRC.

The physiological role of Wnt pathway in normal development and cancer

Over the decades, many studies have illustrated the critical roles of Wnt signaling pathways in both developmental processes as well as tumorigenesis. Due to the complexity of Wnt signaling regulation, there are still questions to be addressed about ways cells are able to manipulate different types of Wnt pathways in order to fulfill the requirements for normal or cancer development. In this review, we will describe different types of Wnt signaling pathways and their roles in both normal developmental processes and their role in cancer development and progression. Additionally, we will briefly introduce new strategies currently in clinical trials targeting Wnt signaling pathway components for cancer therapy.

The role of WNT5A and Ror2 in peritoneal membrane injury

Patients on peritoneal dialysis are at risk of developing peritoneal fibrosis and angiogenesis, which can lead to dysfunction of the peritoneal membrane. Recent evidence has identified cross‐talk between transforming growth factor beta (TGFB) and the WNT/β‐catenin pathway to induce fibrosis and angiogenesis. Limited evidence exists describing the role of non‐canonical WNT signalling in peritoneal membrane injury. Non‐canonical WNT5A is suggested to have different effects depending on the receptor environment. WNT5A has been implicated in antagonizing canonical WNT/β‐catenin signalling in the presence of receptor tyrosine kinase‐like orphan receptor (Ror2). We co‐expressed TGFB and WNT5A using adenovirus and examined its role in the development of peritoneal fibrosis and angiogenesis. Treatment of mouse peritoneum with AdWNT5A decreased the submesothelial thickening and angiogenesis induced by AdTGFB. WNT5A appeared to block WNT/β‐catenin signalling by inhibiting phosphorylation of glycogen synthase kinase 3 beta (GSK3B) and reducing levels of total β‐catenin and target proteins. To examine the function of Ror2, we silenced Ror2 in a human mesothelial cell line. We treated cells with AdWNT5A and observed a significant increase in fibronectin compared with AdWNT5A alone. We also analysed fibronectin and vascular endothelial growth factor (VEGF) in a TGFB model of mesothelial cell injury. Both fibronectin and VEGF were significantly increased in response to Ror2 silencing when cells were exposed to TGFB. Our results suggest that WNT5A inhibits peritoneal injury and this is associated with a decrease in WNT/β‐catenin signalling. In human mesothelial cells, Ror2 is involved in regulating levels of fibronectin and VEGF.

Wnt5a/CaMKII/ERK/CCL2 axis is required for tumor-associated macrophages to promote colorectal cancer progression

Tumor-associated macrophages (TAMs) are closely correlated with tumor occurrence, invasion, and metastasis. However, factors affecting the biological functions of TAMs in colorectal cancer (CRC) are incompletely understood. Here, we found that Wnt5a was mainly expressed on TAMs of tumor stroma but not on CRC cells. Subsequently, we found that Wnt5a⁺ TAMs facilitated tumor cell proliferation and migration, and recruited macrophages infiltration. Furthermore, Wnt5a knockdown impaired the pro-tumor roles of TAMs in vivo and in vitro. Mechanistically, the cancer-promoting roles of Wnt5a in TAMs depended on CaMKII-ERK pathway-mediated CCL2 secretion. Our data reveal the crucial role played by TAM-expressed Wnt5a in CRC tumorigenesis through paracrine secretion of CCL2. We first report the connection between Wnt5a/CaMKII/ERK/CCL2 axis and biological functions of TAMs in tumor microenvironment, indicating that Wnt5a may be a novel therapeutic target for CRC.

An Autocrine Wnt5a Loop Promotes NF-κB Pathway Activation and Cytokine/Chemokine Secretion in Melanoma

Wnt5a signaling has been implicated in the progression of cancer by regulating multiple cellular processes, largely migration and invasion, epithelial-mesenchymal transition (EMT), and metastasis. Since Wnt5a signaling has also been involved in inflammatory processes in infectious and inflammatory diseases, we addressed the role of Wnt5a in regulating NF-κB, a pivotal mediator of inflammatory responses, in the context of cancer. The treatment of melanoma cells with Wnt5a induced phosphorylation of the NF-κB subunit p65 as well as IKK phosphorylation and IκB degradation. By using cDNA overexpression, RNA interference, and dominant negative mutants we determined that ROR1, Dvl2, and Akt (from the Wnt5a pathway) and TRAF2 and RIP (from the NF-κB pathway) are required for the Wnt5a/NF-κB crosstalk. Wnt5a also induced p65 nuclear translocation and increased NF-κB activity as evidenced by reporter assays and a NF-κB-specific upregulation of RelB, Bcl-2, and Cyclin D1. Further, stimulation of melanoma cells with Wnt5a increased the secretion of cytokines and chemokines, including IL-6, IL-8, IL-11, and IL-6 soluble receptor, MCP-1, and TNF soluble receptor I. The inhibition of endogenous Wnt5a demonstrated that an autocrine Wnt5a loop is a major regulator of the NF-κB pathway in melanoma. Taken together, these results indicate that Wnt5a activates the NF-κB pathway and has an immunomodulatory effect on melanoma through the secretion of cytokines and chemokines.

A Complex Role for Calcium Signaling in Colorectal Cancer Development and Progression

Clinical data suggest that many malignant cancers are associated with hypercalcemia. Hypercalcemia can facilitate the proliferation and metastasis of gastric and colon tumors, and has been considered a hallmark of end-stage disease. However, it has also been reported that dietary calcium or vitamin D supplementation could reduce the risk of many types of cancers. In particular, the intestines can absorb considerable amounts of calcium via Ca²⁺-permeable ion channels, and hypercalcemia is common in patients with colorectal cancer. Thus, this review considers the role of calcium signaling in the context of colorectal cancer and summarizes the functions of specific regulators of cellular calcium levels in the proliferation, invasion, metastasis, cell death, and drug resistance of colorectal cancer cells. The data reveal that even a slight upregulation of intracellular Ca²⁺ signaling can facilitate the onset and progression of colorectal cancer, while continuous Ca²⁺ influx and Ca²⁺ overload may cause tumor cell death. This dual function of Ca²⁺ signaling adds nuance to the debate over the hallmarks of colorectal cancer, and may even provide new directions and strategies for clinical interventions.

Diagnostic and prognostic value of WNT family gene expression in hepatitis B virus‑related hepatocellular carcinoma

The aim of the present study was to investigate the diagnostic and prognostic value of Wingless-type MMTV integration site (WNT) gene family expression in patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). The clinical data of the patients and gene expression levels were downloaded from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Receiver operating characteristic curve analysis was used to investigate the diagnostic value of WNT genes. Cox proportional hazard regression analysis and Kaplan-Meier survival analysis were performed to evaluate the association of WNT gene expression level with overall survival (OS) and recurrence-free survival (RFS). A nomogram was constructed for the prediction of prognosis. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated. Diagnostic receiver operating characteristic curve analysis suggested that WNT2 had a high diagnostic value, with an area under the curve (AUC) of >0.800 (P<0.0001, AUC=0.810, 95% CI: 0.767–0.852). Survival analysis indicated that the expression level of WNT1 was significantly associated with OS and RFS (adjusted P=0.033, adjusted HR=0.607, 95% CI: 0.384–0.960; and adjusted P=0.007, adjusted HR=0.592, 95% CI: 0.404–0.868, respectively). In the TCGA validation cohort, we also observed that WNT2 was significantly differentially expressed between HCC tissues and adjacent non-tumor tissues, and WNT1 was associated with both the OS and RFS of HCC. Therefore, through the GSE14520 HBV-related HCC cohort we concluded that WNT2 may serve as a diagnostic biomarker and WNT1 may serve as a prognostic biomarker. These results may also be extended to TCGA HCC verification cohort.

Wnt-11 as a Potential Prognostic Biomarker and Therapeutic Target in Colorectal Cancer

The expression of the secreted factor Wnt-11 is elevated in several types of cancer, including colorectal cancer, where it promotes cancer cell migration and invasion. Analysis of colorectal cancer gene expression databases associated WNT11 mRNA expression with increased likelihood of metastasis in a subset of patients. WNT11 expression was correlated with the expression of the Wnt receptors FZD6, RYK, and PTK7, and the combined expression of WNT11, FZD6 and RYK or PTK7 was associated with an increased risk of 5-year mortality rates. Immunohistochemical analysis of Wnt-11 in a cohort of 357 colorectal cancer patients found significantly higher Wnt-11 levels in tumors, compared with benign tissue. Elevated Wnt-11 levels occurred more frequently in rectal tumors than in colonic tumors and in tumors from women than men. In univariate analysis, increased Wnt-11 expression was also associated with tumor invasion and increased 5-year mortality. High Wnt-11 levels were not associated with high levels of nuclear β-catenin, suggesting Wnt-11 is not simply an indicator for activation of β-catenin-dependent signaling. Expression of Wnt-11 in colorectal cancer cell lines expressing low endogenous Wnt-11 inhibited β-catenin/Tcf activity and increased ATF2-dependent transcriptional activity. WNT11 gene silencing and antibody-mediated inhibition of Wnt-11 in colorectal cancer cell lines expressing high Wnt-11 reduced their capacity for invasion. Together, these observations suggest that Wnt-11 could be a potential target for the treatment of patients with invasive colorectal cancer.

Upregulation of FZD5 in Eosinophilic Chronic Rhinosinusitis with Nasal Polyps by Epigenetic Modification

Eosinophilic chronic rhinosinusitis with nasal polyps (CRSwNP) is one of the most challenging problems in clinical rhinology. FZD5 is a receptor for Wnt5A, and its complex with Wnt5A contributes to activating inflammation and tissue modification. Nasal polyps and eosinophil/non-eosinophil counts are reported to be directly correlated. This study investigated the expression and distribution of FZD5, and the role of eosinophil infiltration and FZD5 in eosinophilic CRSwNP pathogenesis. The prognostic role of eosinophil levels was evaluated in seven patients with CRSwNP. Fifteen patients with CRS were classified based on the percentage of eosinophils in nasal polyp tissue. Methylated genes were detected using methyl-CpG-binding domain sequencing, and qRT-PCR and immunohistochemistry were used to detect FZD5 expression in nasal polyp tissue samples. The results showed that mRNA expression of FZD5 was upregulated in nasal polyps. FZD5 expression was significantly higher in nasal polyp samples from patients with eosinophilic CRSwNP than in those from patients with non-eosinophilic CRSwNP, as indicated by immunohistochemistry. Furthermore, inflammatory cytokine levels were higher in eosinophilic CRSwNP-derived epithelial cells than in normal tissues. In conclusion, FZD5 expression in nasal mucosal epithelial cells is correlated with inflammatory cells and might play a role in the pathogenesis of eosinophilic CRSwNP.

The Role of Wnt Pathway in the Pathogenesis of OA and Its Potential Therapeutic Implications in the Field of Regenerative Medicine

Introduction

Osteoarthritis (OA) is a degenerative joint disease characterized by articular cartilage degradation, subchondral damage, and bone remodelling, affecting most commonly weight-bearing joints, such as the knee and hip. The loss of cartilage leads to joint space narrowing, pain, and loss of function which could ultimately require total joint replacement. The Wnt/β catenin pathway is involved in the pathophysiology of OA and has been proposed as a therapeutic target. Endogenous and pharmacological inhibitors of this pathway were recently investigated within innovative therapies including the use of platelet-rich plasma (PRP) and mesenchymal stem cells (MSCs).

Methods

A review of the literature was performed on the PubMed database based on the following inclusion criteria: article written in English language in the last 20 years and dealing with (1) the role of Wnt-β catenin pathway in the pathogenesis of osteoarthritis and (2) pharmacologic or biologic strategies modulating the Wnt-β catenin pathway in the OA setting.

Results

Evidences support that Wnt signalling pathway is likely linked to OA progression and severity. Its inhibition through natural antagonists and new synthetic or biological drugs shares the potential to improve the clinical condition of the patients by affecting the pathological activity of Wnt/β-catenin signalling.

Conclusions

While further research is needed to better understand the mechanisms regulating the molecular interaction between OA regenerative therapies and Wnt, it seems that biologic therapies for OA exert modulation on Wnt/β catenin pathway that might be relevant in achieving the beneficial clinical effect of those therapeutic strategies.

The Zinc Finger Transcription Factor PLAGL2 Enhances Stem Cell Fate and Activates Expression of ASCL2 in Intestinal Epithelial Cells

Intestinal epithelial stem cell (IESC) fate is promoted by two major transcriptional regulators, the TCF4/β-catenin complex and ASCL2, which drive expression of IESC-specific factors, including Lgr5, Ephb2, and Rnf43. Canonical Wnt signaling via TCF4/β-catenin directly transactivates Ascl2, which in turn auto-regulates its own expression. Conversely, Let-7 microRNAs antagonize the IESC lineage by repressing specific mRNA targets. Here, we identify the zinc finger transcription factor PLAGL2 as a Let-7 target that regulates IESC fate. PLAGL2 drives an IESC expression signature, activates Wnt gene expression, and enhances a TCF/LEF reporter in intestinal organoids. In parallel, via cell-autonomous mechanisms, PLAGL2 is required for lineage clonal expansion and directly enhances expression of ASCL2. PLAGL2 also supports enteroid growth and survival in the context of Wnt ligand depletion. PLAGL2 expression is strongly associated with an IESC signature in colorectal cancer and may be responsible for contributing to the aberrant activation of an immature phenotype.

The Coordinated Activities of nAChR and Wnt Signaling Regulate Intestinal Stem Cell Function in Mice

Cholinergic signaling, which modulates cell activities via nicotinic and muscarinic acetylcholine receptors (n- and mAChRs) in response to internal or external stimuli, has been demonstrated in mammalian non-neuronal cells that synthesize acetylcholine (ACh). One of the major pathways of excitatory transmission in the enteric nervous system (ENS) is mediated by cholinergic transmission, with the transmitter ACh producing excitatory potentials in postsynaptic effector cells. In addition to ACh-synthesizing and ACh-metabolizing elements in the ENS, the presence of non-neuronal ACh machinery has been reported in epithelial cells of the small and large intestines of rats and humans. However, little is known about how non-neuronal ACh controls physiological function in the intestine. Here, experiments using crypt-villus organoids that lack nerve and immune cells in culture suggest that endogenous ACh is synthesized in the intestinal epithelium to drive organoid growth and differentiation through activation of nAChRs. Treatment of organoids with nicotine enhanced cell growth and the expression of marker genes for stem and epithelial cells. On the other hand, the nAChR antagonist mecamylamine strongly inhibited the growth and differentiation of organoids, suggesting the involvement of nAChRs in the regulation of proliferation and differentiation of Lgr5-positive stem cells. More specifically, RNA sequencing analysis revealed that Wnt5a expression was dramatically upregulated after nicotine treatment, and Wnt5a rescued organoid growth and differentiation in response to mecamylamine. Taken together, our results indicate that coordinated activities of nAChR and Wnt signaling maintain Lgr5-positive stem cell activity and balanced differentiation. Furthermore, we could clearly separate the two groups, neuronal ACh in the ENS and non-neuronal ACh in the intestinal epithelium. Dysfunction of the non-neuronal cholinergic system is involved in the pathogenesis of disease. The data will increase our understanding of the cholinergic properties of non-neuronal cells and lead to optimization of drug therapy.

Epithelial-to-endothelial transition and cancer stem cells: two cornerstones of vasculogenic mimicry in malignant tumors

Vasculogenic mimicry (VM) is a functional microcirculation pattern in malignant tumors accompanied by endothelium-dependent vessels and mosaic vessels. VM has been identified in more than 15 solid tumor types and is associated with poor differentiation, late clinical stage and poor prognosis. Classic anti-angiogenic agents do not target endothelium-dependent vessels and are not efficacious against tumors exhibiting VM. Further insight into the molecular signaling that triggers and promotes VM formation could improve anti-angiogenic therapeutics. Recent studies have shown that cancer stem cells (CSCs) and epithelium-to-endothelium transition (EET), a subtype of epithelial-to-mesenchymal transition (EMT), accelerate VM formation by stimulating tumor cell plasticity, remodeling the extracellular matrix (ECM) and connecting VM channels with host blood vessels. VM channel-lining cells originate from CSCs due to expression of EMT inducers such as Twist1, which promote EET and ECM remodeling. Hypoxia and high interstitial fluid pressure in the tumor microenvironment induce a specific type of cell death, linearly patterned programmed cell necrosis (LPPCN), which spatially guides VM and endothelium-dependent vessel networks. This review focuses on the roles of CSCs and EET in VM, and on possible novel anti-angiogenic strategies against alternative tumor vascularization.

Differential effects of Wnt5a on the proliferation, differentiation and inflammatory response of keratinocytes

The predominant role of Wnt family member 5A (Wnt5a) is to induce non-canonical Wnt signalling pathways, including the Wnt‑Ca2+ and Wnt‑planar cell polarity pathways. Enhanced Wnt5a expression is involved in the formation of psoriatic plaques; however, its mechanistic role remains to be determined. In the present study, the effects of Wnt5a expression on HaCaT keratinocytes were investigated. HaCaT cells were cultured in medium supplemented with 0, 40 or 80 ng/ml Wnt5a for 24 h. Cell proliferation, the cell cycle, gene expression and inflammatory responses were investigated using Cell‑Counting Kit‑8 assays, flow cytometry analyses, reverse transcription‑quantitative polymerase chain reaction analyses and enzyme‑linked immunosorbent assays, respectively. Wnt5a treatment was revealed to suppress cell proliferation in HaCaT cells. Furthermore, Wnt5a was also demonstrated to increase the proportion of HaCaT cells arrested at the G2/M phase of the cell cycle, but reduce the proportion of HaCaT cells arrested at G0/G1 phase cells. In addition, the expression levels of the differentiation markers, including filaggrin, keratin 1 and keratin 10 were revealed to be downregulated in HaCaT cells. Expression of the canonical Wnt signalling genes (β‑catenin and cyclin D1) and proliferation markers, such as Ki‑67 and proliferating cell nuclear antigen in HaCaT cells were also revealed to be downregulated. However, the expression levels of inflammatory response markers (interferon‑γ, interleukin‑8 and interleukin‑17A) were revealed to be upregulated in HaCaT cells following Wnt5a treatment. These findings suggest that Wnt5a expression may be involved in the inhibition of cell differentiation and the induction of an inflammatory response in patients with psoriasis.

Mediation of cellular osteogenic differentiation through daily stimulation time based on polypyrrole planar electrodes

In electrical stimulation (ES), daily stimulation time means the interacting duration with cells per day, and is a vital factor for mediating cellular function. In the present study, the effect of stimulation time on osteogenic differentiation of MC3T3-E1 cells was investigated under ES on polypyrrole (Ppy) planar interdigitated electrodes (IDE). The results demonstrated that only a suitable daily stimulation time supported to obviously upregulate the expression of ALP protein and osteogenesis-related genes (ALP, Col-I, Runx2 and OCN), while a short or long daily stimulation time showed no significant outcomes. These might be attributed to the mechanism that an ES induced transient change in intracellular calcium ion concentration, which was responsible for activating calcium ion signaling pathway to enhance cellular osteogenic differentiation. A shorter daily time could lead to insufficient duration for the transient change in intracellular calcium ion concentration, and a longer daily time could give rise to cellular fatigue with no transient change. This work therefore provides new insights into the fundamental understanding of cell responses to ES and will have an impact on further designing materials to mediate cell behaviors.

Wnt5a promotes epithelial-to-mesenchymal transition and metastasis in non-small-cell lung cancer

A recent study indicated that high Wnt5a expression is associated with poor prognosis in non-small-cell lung cancer (NSCLC) patients; however, the underlying mechanism was not clear yet. Immunohistochemistry and Western blotting were performed to examine the protein expression level in NSCLC tissues and cell lines. The role of Wnt5a in clone formation, invasiveness, migration, and epithelial-to-mesenchymal transition (EMT) of NSCLC cells was studied. Luciferase reporter assay was used to evaluate the Tcf/Lef transcriptional activity. For assessing the effects of Wnt5a on tumor growth and metastasis in vivo, A549 cells transfected with sh-Wnt5a were subcutaneously or orthotopically injected into nude mice. In NSCLC tissues, higher expression levels of Wnt5a and ROR2 were found, β-Catenin was expressed exceptionally, and EMT was prompted. Wnt5a overexpression increased clone formation, migration, and invasion, as well as prompted EMT of NSCLC cell in vitro, whereas Wnt5a knockdown showed the absolutely reversed results. Wnt5a overexpression enhanced the Tcf/Lef transcriptional activity and elevated the nuclear β-catenin level in NSCLC cells, without altering the ROR2 expression. We also demonstrated that si-β-catenin antagonized Wnt5a overexpression nduced EMT and invasiveness. Besides, in vivo experiment showed that sh-Wnt5a significantly increased tumor volume and tumor weight, and prompted EMT in A549 tumor-bearing mice as compared with the control. No metastasis was found in the liver tissue after sh-Wnt5a-transfected cells were orthotopically injected into nude mice as compared with the control. In conclusion, Wnt5a promotes EMT and metastasis in NSCLC, which is involved in the activation of β-catenin-dependent canonical Wnt signaling.

Cellular and molecular mechanisms underlying planar cell polarity pathway contributions to cancer malignancy

While the mutational activation of oncogenes drives tumor initiation and growth by promoting cellular transformation and proliferation, increasing evidence suggests that the subsequent re-engagement of largely dormant developmental pathways contributes to cellular phenotypes associated with the malignancy of solid tumors. Genetic studies from a variety of model organisms have defined many of the components that maintain epithelial planar cell polarity (PCP), or cellular polarity in the axis orthogonal to the apical-basal axis. These same components comprise an arm of non-canonical Wnt signaling that mediates cell motility events such as convergent extension movements essential to proper development. In this review, we summarize the increasing evidence that the Wnt/PCP signaling pathway plays active roles in promoting the proliferative and migratory properties of tumor cells, emphasizing the importance of subcellular localization of PCP components and protein-protein interactions in regulating cellullar properties associated with malignancy. Specifically, we discuss the increased expression of Wnt/PCP pathway components in cancer and the functional consequences of aberrant pathway activation, focusing on Wnt ligands, Frizzled (Fzd) receptors, the tetraspanin-like proteins Vangl1 and Vangl2, and the Prickle1 (Pk1) scaffold protein. In addition, we discuss negative regulation of the Wnt/PCP pathway, with particular emphasis on the Nrdp1 E3 ubiquitin ligase. We hypothesize that engagement of the Wnt/PCP pathway after tumor initiation drives malignancy by promoting cellular proliferation and invasiveness, and that the ability of Wnt/PCP signaling to supplant oncogene addiction may contribute to tumor resistance to oncogenic pathway-directed therapeutic agents.

Distinct roles and differential expression levels of Wnt5a mRNA isoforms in colorectal cancer cells

The canonical Wnt/β-catenin pathway is constitutively activated in more than 90% of colorectal cancer (CRC) cases in which β-catenin contributes to CRC cell growth and survival. In contrast to the Wnt/β-catenin pathway, the non-canonical Wnt pathway can antagonize functions of the canonical Wnt/β-catenin pathway. Wnt5a is a key factor in the non-canonical Wnt pathway, and it plays diverse roles in different types of cancers. It was shown that reintroducing Wnt5a into CRC cells resulted in inhibited cell proliferation and impaired cell motility. However, contradictory results were reported describing increased Wnt5a expression being associated with a poor prognosis of CRC patients. Recently, it was shown that the diverse roles of Wnt5a are due to two distinct roles of Wnt5a isoforms. However, the exact roles and functions of the Wnt5a isoforms in CRC remain largely unclear. The present study for the first time showed the ambiguous role of Wnt5a in CRC was due to the encoding of distinct roles of the various Wnt5a mRNA isoforms. A relatively high expression level of the Wnt5a-short (S) isoform transcript and a low expression level of the Wnt5a-long (L) isoform transcript were detected in CRC cell lines and specimens. In addition, high expression levels of the Wnt5a-S mRNA isoform and low expression levels of the Wnt5a-L mRNA isoform were significantly positively correlated with tumor depth of CRC patients. Furthermore, knockdown of the endogenous expression of the Wnt5a-S mRNA isoform in HCT116 cells drastically inhibited their growth ability by inducing apoptosis through induction of FASLG expression and reduction of TNFRSF11B expression. Moreover, reactivation of methylation inactivation of the Wnt5a-L mRNA isoform by treatment with 5-azacytidine (5-Aza) enhanced the siWnt5a-S isoform's ability to induce apoptosis. Finally, we showed that the simultaneous reactivation of Wnt5a-L mRNA isoform and knockdown of Wnt5a-S mRNA isoform expression enhanced siWnt5a-S isoform-induced apoptosis and siWnt5a-L isoform-regulated suppression of β-catenin expression in vitro. High expression levels of the Wnt5a-S mRNA isoform and low expression levels of the Wnt5a-L mRNA isoform were significantly positively correlated with high mRNA levels of β-catenin detection in vivo. Altogether, our study showed that, for the first time, different Wnt5a mRNA isoforms play distinct roles in CRC and can be used as novel prognostic markers for CRC in the future.

EZH2 is involved in silencing of WNT5A during epithelial-mesenchymal transition of colon cancer cell line

PURPOSE

Transforming growth factor-β (TGF-β) induction of epithelial-mesenchymal transition (EMT) in SW480 was established as a system for studies of colon cancer metastasis. However, the epigenetic mechanisms underlying this process remain unknown. In mammal, polycomb repressive complex-2 (PRC2) is a highly conserved histone methyltransferase involved in epigenetic regulations. Enhancer of zeste Homolog 2 (EZH2) is the catalytic subunit of PRC2, which catalyzes methylation of lysine 27 of histone H3 (H3K27).

METHODS

An inducible EMT system in colorectal cancer was utilized to study its mechanistic and phenotypic changes. Particularly, gene expression analysis was studied after immunoprecipitation.

RESULTS

In this study, we reported that EZH2 is significantly enriched in the promoter region of WNT5A after TGF-β induction in SW480 colon cancer cell line, which in turn silenced the expression of WNT5A. Furthermore, EZH2 inhibitor antagonized the TGF-β-induced morphological conversion associated with epithelial-mesenchymal transition (EMT). Conversely, inhibition of histone H3K27me3 reader CBX does not affect the WNT5A expression level during TGF-β-induced EMT.

CONCLUSIONS

Our results indicate that EZH2 was essential for the silencing of WNT5A during TGF-β-induced epithelial-mesenchymal transition of colon cancer cells.

RSPO2 suppresses colorectal cancer metastasis by counteracting the Wnt5a/Fzd7-driven noncanonical Wnt pathway

R-spondins play critical roles in development, stem cell survival, and tumorigenicity by modulating Wnt/β-catenin signaling; however, the role of R-spondins in noncanonical Wnt signaling regulation remains largely unknown. We demonstrate here that R-spondin 2 (RSPO2) has an inhibitory effect on colorectal cancer (CRC) cell migration, invasion, and metastasis. Reduced RSPO2 expression was associated with tumor metastasis and poor survival in CRC patients. The metastasis-suppressive activity of RSPO2 was independent of the Wnt/β-catenin signaling pathway but dependent on the Fzd7-mediated noncanonical Wnt signaling pathway. The physical interaction of RSPO2 and Fzd7 increased the degradation of cell surface Fzd7 via ZNRF3-mediated ubiquitination, which led to the suppression of the downstream PKC/ERK signaling cascade. In late-stage metastatic cancer, Wnt5a promoted CRC cell migration by preventing degradation of Fzd7, and RSPO2 antagonized Wnt5a-driven noncanonical Wnt signaling activation and tumor cell migration by blocking the binding of Wnt5a to the Fzd7 receptor. Our study reveals a novel RSPO2/Wnt5a-competing noncanonical Wnt signaling mechanism that regulates cellular migration and invasion, and our data suggest that secreted RSPO2 protein could serve as a potential therapy for Wnt5a/Fzd7-driven aggressive CRC tumors.

Association between Wnt inhibitory factor 1 and receptor tyrosine kinase-like orphan receptor 2 protein expression and the clinical pathological significance in benign and malignant pancreatic lesions

Pancreatic cancer is one of the most malignant types of tumor. It is important to elucidate the underlying molecular mechanisms of pancreatic tumorigenesis and to identify novel biomarkers as therapeutic targets of pancreatic cancer. In the present study, the protein expression levels of Wnt inhibitory factor 1 (WIF1) and receptor tyrosine kinase-like orphan receptor 2 (ROR2) were examined in a collection of pancreatic ductal carcinoma and benign pancreatic lesion tissue samples using immunohistochemistry. The positive expression rate of WIF1 protein in pancreatic ductal carcinoma was demonstrated to be significantly decreased compared with that of the paracancerous tissue, benign lesions and wild-type pancreatic tissue (P=0.002, P<0.0001, P=0.001, respectively). The positive expression rate of ROR2 protein in pancreatic ductal carcinoma was demonstrated to be significantly increased compared with that of the paracancerous tissue, benign lesions and wild-type pancreatic tissue (P<0.0001). There was a negative association between WIF1 and ROR2 expression in the pancreatic ductal carcinoma samples (P=0.004). The survival period of patients with negative WIF1 and positive ROR2 protein expression was demonstrated to be significantly decreased compared with that of patients with positive WIF1 and negative ROR2 protein expression (P<0.0001). The expression levels of WIF1 and ROR2 protein reflected the incidence, development, clinical and biological behavior, and prognosis of pancreatic ductal carcinoma. Patients with negative WIF1 and positive ROR2 protein expression had poor prognosis. The results indicate that WIF1 and ROR2 are important biomarkers in pancreatic cancer.

Reduced production and uptake of lactate are essential for the ability of WNT5A signaling to inhibit breast cancer cell migration and invasion

Here we investigated the impact of WNT5A signaling on aerobic glycolysis and evaluated its effects on breast cancer cell migration/invasion. WNT5A signaling reduced migration and lactate production and caused selective down-regulation of the glycolytic enzyme phosphofructokinase platelet-type (PFKP). These events occurred in parallel with a WNT5A-induced inhibition of β-catenin signaling. Support for essential involvement of β-catenin and PFKP in lactate production and migration/invasion was obtained by siRNA knockdown of their expression. To also explore the effect of non-tumor cell-derived lactate, we added exogenous lactate to the cells and noted an increase in migration that was significantly impaired by recombinant WNT5A in parallel with a down-regulation of the lactate transporter monocarboxylate transporter 1 (MCT1). Interestingly enough, the drug-candidate Foxy5 (WNT5A-mimic hexapeptide) also inhibited breast cancer cell migration in the presence of exogenous lactate, suggesting a therapeutic potential for Foxy5 in managing breast tumors with high glycolytic activity. Overall, we demonstrated that WNT5A signaling (via a β-catenin-PFKP axis) reduces lactate production and lowers the expression of MCT1, a carrier mediating the uptake of lactate from the tumor microenvironment. These effects of WNT5A are essential for its ability to impair breast cancer migration/invasion even in an environment with elevated lactate levels.