Frizzled homolog proteins, microRNAs and Wnt signaling in cancer

Pan-cancer drivers of metastasis

Metastasis remains a leading cause of cancer-related mortality, irrespective of the primary tumour origin. However, the core gene regulatory program governing distinct stages of metastasis across cancers remains poorly understood. We investigate this through single-cell transcriptome analysis encompassing over two hundred patients with metastatic and non-metastatic tumours across six cancer types. Our analysis revealed a prognostic core gene signature that provides insights into the intricate cellular dynamics and gene regulatory networks driving metastasis progression at the pan-cancer and single-cell level. Notably, the dissection of transcription factor networks active across different stages of metastasis, combined with functional perturbation, identified SP1 and KLF5 as key regulators, acting as drivers and suppressors of metastasis, respectively, at critical steps of this transition across multiple cancer types. Through in vivo and in vitro loss of function of SP1 in cancer cells, we revealed its role in driving cancer cell survival, invasive growth, and metastatic colonisation. Furthermore, tumour cells and the microenvironment increasingly engage in communication through WNT signalling as metastasis progresses, driven by SP1. Further validating these observations, a drug repurposing analysis identified distinct FDA-approved drugs with anti-metastasis properties, including inhibitors of WNT signalling across various cancers.

Exploring circulating MiRNA signature for osteosarcoma detection: Bioinformatics-based analyzing and validation

Early detection followed by efficient treatment still remain a considerable challenge for osteosarcoma (OS), indicating the importance of emerging innovative diagnostic methods. Circulating miRNAs offer a promising and non-invasive approach to assess the OS molecular landscapes. This study utilized RNAseq data from OS plasma miRNA expression profiles (PRJEB30542) and PCR Array data (GSE65071) from GEO and ENA databases. In total, 43 miRNAs demonstrated significant differential expression in OS samples of training dataset. A diagnostic model, including hsa-miR-30a-5p, hsa-miR-556-3p, hsa-miR-200a-3p, and hsa-miR-582-5p was identified through multivariate logistic regression analysis and demonstrated significant efficacy in differentiating OS patients from healthy controls in the validation group (AUC: 0.917, sensitivity: 1, specificity: 0.85). The result of target gene prediction and functional enrichment analyses revealed significant associations with terms such as epithelial morphogenesis, P53 and Wnt signaling pathways, and neoplasm metastasis. Further bioinformatics-based evaluations showed that the down-regulation of these miRNAs significantly correlates with poor prognosis and lower survival rate in OS patients and propose their tumor suppressor function in pathogenesis of OS. Furthermore, the study developed a miRNA-mRNA subnetwork that connects these miRNAs to the P53 and Wnt signaling pathways, which are critical pathways with oncogenic effects on OS progression. This comprehensive approach not only presents a promising diagnostic model but also proposes potential molecular markers for OS early diagnosis, making prognosis, and targeted therapy. The identified miRNA-mRNA functional axis holds promise as a valuable resource for further research in understanding OS pathogenesis and establishing therapeutic modalities.

Role of the lncRNA/Wnt signaling pathway in digestive system cancer: a literature review

The long noncoding RNA (lncRNA)/Wingless (Wnt) axis is often dysregulated in digestive system tumors impacting critical cellular processes. Abnormal expression of specific Wnt-related lncRNAs such as LINC01606 (promotes motility), SLCO4A1-AS1 (promotes motility), and SH3BP5-AS1 (induces chemoresistance), plays a crucial role in these malignancies. These lncRNAs are promising targets for cancer diagnosis and therapy, offering new treatment perspectives. The lncRNAs, NEF and GASL1, differentially expressed in plasma show diagnostic potential for esophageal squamous cell carcinoma and gastric cancer, respectively. Additionally, Wnt pathway inhibitors like XAV-939 have demonstrated preclinical efficacy, underscoring their therapeutic potential. This review comprehensively analyzes the lncRNA/Wnt axis, highlighting its impact on cell proliferation, motility, and chemoresistance. By elucidating the complex molecular mechanisms of the lncRNA/Wnt axis, we aim to identify potential therapeutic targets for digestive system tumors to pave the way for the development of targeted treatment strategies.

Proteomic analysis of the developing mammalian brain links PCDH19 to the Wnt/β-catenin signalling pathway

Clustering Epilepsy (CE) is a neurological disorder caused by pathogenic variants of the Protocadherin 19 (PCDH19) gene. PCDH19 encodes a protein involved in cell adhesion and Estrogen Receptor α mediated-gene regulation. To gain further insights into the molecular role of PCDH19 in the brain, we investigated the PCDH19 interactome in the developing mouse hippocampus and cortex. Combined with a meta-analysis of all reported PCDH19 interacting proteins, our results show that PCDH19 interacts with proteins involved in actin, microtubule, and gene regulation. We report CAPZA1, αN-catenin and, importantly, β-catenin as novel PCDH19 interacting proteins. Furthermore, we show that PCDH19 is a regulator of β-catenin transcriptional activity, and that this pathway is disrupted in CE individuals. Overall, our results support the involvement of PCDH19 in the cytoskeletal network and point to signalling pathways where PCDH19 plays critical roles.

Network-driven cancer cell avatars for combination discovery and biomarker identification for DNA damage response inhibitors

Combination therapy is well established as a key intervention strategy for cancer treatment, with the potential to overcome monotherapy resistance and deliver a more durable efficacy. However, given the scale of unexplored potential target space and the resulting combinatorial explosion, identifying efficacious drug combinations is a critical unmet need that is still evolving. In this paper, we demonstrate a network biology-driven, simulation-based solution, the Simulated Cell™. Integration of omics data with a curated signaling network enables the accurate and interpretable prediction of 66,348 combination-cell line pairs obtained from a large-scale combinatorial drug sensitivity screen of 684 combinations across 97 cancer cell lines (BAC = 0.62, AUC = 0.7). We highlight drug combination pairs that interact with DNA Damage Response pathways and are predicted to be synergistic, and deep network insight to identify biomarkers driving combination synergy. We demonstrate that the cancer cell 'avatars' capture the biological complexity of their in vitro counterparts, enabling the identification of pathway-level mechanisms of combination benefit to guide clinical translatability.

Circular RNAs: characteristics, functions, mechanisms, and potential applications in thyroid cancer

Thyroid cancer (TC) is one of the most common endocrine malignancies, and its incidence has increased globally. Despite extensive research, the underlying molecular mechanisms of TC remain partially understood, warranting continued exploration of molecular markers for diagnostic and prognostic applications. Circular RNAs (circRNAs) have recently garnered significant attention owing to their distinct roles in cancers. This review article introduced the classification and biological functions of circRNAs and summarized their potential as diagnostic and prognostic markers in TC. Further, the interplay of circRNAs with PI3K/Akt/mTOR, Wnt/β-catenin, MAPK/ERK, Notch, JAK/STAT, and AMPK pathways is elaborated upon. The article culminates with an examination of circRNA's role in drug resistance of TC and highlights the challenges in circRNA research in TC.

MicroRNAs: Potential prognostic and theranostic biomarkers in chronic lymphocytic leukemia

Small noncoding ribonucleic acids called microRNAs coordinate numerous critical physiological and biological processes such as cell division, proliferation, and death. These regulatory molecules interfere with the function of many genes by binding the 3'-UTR region of target mRNAs to inhibit their translation or even degrade them. Given that a large proportion of miRNAs behave as either tumor suppressors or oncogenes, any genetic or epigenetic aberration changeing their structure and/or function could initiate tumor formation and development. An example of such cancers is chronic lymphocytic leukemia (CLL), the most prevalent adult leukemia in Western nations, which is caused by unregulated growth and buildup of defective cells in the peripheral blood and lymphoid organs. Genetic alterations at cellular and molecular levels play an important role in the occurrence and development of CLL. In this vein, it was noted that the development of this disease is noticeably affected by changes in the expression and function of miRNAs. Many studies on miRNAs have shown that these molecules are pivotal in the prognosis of different cancers, including CLL, and their epigenetic alterations (e.g., methylation) can predict disease progression and response to treatment. Furthermore, miRNAs are involved in the development of drug resistance in CLL, and targeting these molecules can be considered a new therapeutic approach for the treatment of this disease. MiRNA screening can offer important information on the etiology and development of CLL. Considering the importance of miRNAs in gene expression regulation, their application in the diagnosis, prognosis, and treatment of CLL is reviewed in this paper.

Exploring signaling pathway crosstalk in glioma by mapping miRNA and WNT pathways: A review

Glioma is a significant healthcare burden; nevertheless, the particular genetic regulatory mechanism underpinning its onset and progression is still unknown. Recent research has focused in large part on trying to determine the underlying molecular pathways that contribute to the malignancy of this disease because of the difficulties in treating it. Many tumors have been linked to changes in the expression of microRNAs (miRNAs). miRNAs play a critical role in cancer development by controlling a wide variety of targets and signaling cascades. A rising body of evidence emphasizes WNT pathway dysregulation in glioma, despite the fact that it is dysregulated in many malignancies. Here, we give a detailed analysis of the roles played by miRNAs in the WNT pathway by glioma. We also demonstrate how the WNT pathway cooperates with miRNAs to control a variety of functions, including cell proliferation, invasion, migration, and epithelial-mesenchymal transition.

Computational analysis of bevacizumab binding with protein receptors for its potential anticancer activity

Breast cancer poses a significant global challenge, prompting researchers to explore novel approaches for potential treatments. In this study, we investigated the binding free energy (ΔG) of bevacizumab, an anti-cancer therapy targeting angiogenesis through the inhibition of vascular endothelial growth factor (VEGF), with various proto-oncogenes including CDK4, EGFR, frizzled, IGFR, OmoMYC, and KIT. Our in-silico investigation revealed that hydrogen bonding is pivotal in inducing conformational changes within the DNA structure, impeding its replication and preventing cell death. Molecular docking results revealed the presence of crucial hydrogen bonds and supported the formation of stable bevacizumab complexes. The molecular docking scores for the tested complexes were CDK4 (Score = -7.2 kcal/mol), EGFR (Score = -8.5 kcal/mol), frizzled (Score = -6.9 kcal/mol), IGFR (Score = -7.8 kcal/mol), KIT (Score = -6.5 kcal/mol), and MYC (Score = -8.3 kcal/mol). The binding mode demonstrated vital hydrogen bonds correlated with the observed energy gap. Notably, the calculated binding free energies of the tested compounds are as follows: CDK4 (ΔG = 24275.195 ± 6411.293 kJ/mol), EGFR (ΔG = 363273.625 ± 8731.466 kJ/mol), frizzled (ΔG = 181751.990 ± 28438.515 kJ/mol), IGFR (ΔG = 162414.725 ± 10728.367 kJ/mol), KIT (ΔG = 40162.585 ± 4331.017 kJ/mol), and MYC (ΔG = 434783.463 ± 53989.676 kJ/mol). Furthermore, through extensive 100 ns MD simulations, we observed the formation of a stable bevacizumab complex structure. The simulations confirmed the stability of the bevacizumab complex with the proto-oncogenes. The results of this study highlight the potential of bevacizumab complex as a promising candidate for anticancer treatment. The identification of hydrogen bonding, along with the calculated binding free energies and molecular docking scores, provides valuable insights into the molecular interactions and stability of the bevacizumab complexes. These findings and the extensive MD simulations open new avenues for future research and development of bevacizumab as a targeted therapy for breast cancer and other related malignancies.Communicated by Ramaswamy H. Sarma.

Multiomic analysis implicates nuclear hormone receptor signalling in clustering epilepsy

Clustering Epilepsy (CE) is an epileptic disorder with neurological comorbidities caused by heterozygous variants of the X chromosome gene Protocadherin 19 (PCDH19). Recent studies have implicated dysregulation of the Nuclear Hormone Receptor (NHR) pathway in CE pathogenesis. To obtain a comprehensive overview of the impact and mechanisms of loss of PCDH19 function in CE pathogenesis, we have performed epigenomic, transcriptomic and proteomic analysis of CE relevant models. Our studies identified differential regulation and expression of Androgen Receptor (AR) and its targets in CE patient skin fibroblasts. Furthermore, our cell culture assays revealed the repression of PCDH19 expression mediated through ERα and the co-regulator FOXA1. We also identified a protein-protein interaction between PCDH19 and AR, expanding upon the intrinsic link between PCDH19 and the NHR pathway. Together, these results point to a novel mechanism of NHR signaling in the pathogenesis of CE that can be explored for potential therapeutic options.

Deciphering signaling pathway interplay via miRNAs in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a highly invasive form of lung cancer that adversely affects the pleural and other linings of the lungs. MPM is a very aggressive tumor that often has an advanced stage at diagnosis and a bad prognosis (between 7 and 12 months). When people who have been exposed to asbestos experience pleural effusion and pain that is not explained, MPM should be suspected. After being diagnosed, most MPM patients have a one- to four-year life expectancy. The life expectancy is approximately six months without treatment. Despite the plethora of current molecular investigations, a definitive universal molecular signature has yet to be discovered as the causative factor for the pathogenesis of MPM. MicroRNAs (miRNAs) are known to play a crucial role in the regulation of gene expression at the posttranscriptional level. The association between the expression of these short, non-coding RNAs and several neoplasms, including MPM, has been observed. Although the incidence of MPM is very low, there has been a significant increase in research focused on miRNAs in the past few years. In addition, miRNAs have been found to have a role in various regulatory signaling pathways associated with MPM, such as the Notch signaling network, Wnt/β-catenin, mutation of KRAS, JAK/STAT signaling circuit, protein kinase B (AKT), and Hedgehog signaling pathway. This study provides a comprehensive overview of the existing understanding of the roles of miRNAs in the underlying mechanisms of pathogenic symptoms in MPM, highlighting their potential as viable targets for therapeutic interventions.

The acquisition order of leukemic drug resistance mutations is directed by the selective fitness associated with each resistance mechanism

In Chronic Myeloid Leukemia, the transition from drug sensitive to drug resistant disease is poorly understood. Here, we used exploratory sequencing of gene transcripts to determine the mechanisms of drug resistance in a dasatinib resistant cell line model. Importantly, cell samples were collected sequentially during drug exposure and dose escalation, revealing several resistance mechanisms which fluctuated over time. BCR::ABL1 overexpression, BCR::ABL1 kinase domain mutation, and overexpression of the small molecule transporter ABCG2, were identified as dasatinib resistance mechanisms. The acquisition of mutations followed an order corresponding with the increase in selective fitness associated with each resistance mechanism. Additionally, it was demonstrated that ABCG2 overexpression confers partial ponatinib resistance. The results of this study have broad applicability and help direct effective therapeutic drug usage and dosing regimens and may be useful for clinicians to select the most efficacious therapy at the most beneficial time.

In silico analysis reveals mir-98-5p as a potential inhibitor of tumor cell proliferation and metastasis in colorectal cancer by targeting the fzd3 receptor of the Wnt signaling pathway

BACKGROUND

Colorectal Cancer (CRC) is the third most common cancer type and the second leading cause of cancer-related deaths worldwide. However, the existing treatment, as well as prognosis strategies for CRC patients, need to be improved in order to increase the chance of survival. Targeted therapies of CRC, as opposed to ordinary therapies, target key biological features and pathways of cancerous cells hence minimizing the subsequent damage to normal cells. MicroRNAs have been reported to play a crucial role in inhibiting and/or suppressing major pathways in various cancer types by targeting transcripts of key genes in such pathways.

METHODS

The purpose of this study was to analyze in silico the differentially expressed genes from five microarray datasets of patients with CRC. Furthermore, miRNAs were investigated to inhibit cancer cell proliferation and metastasis by targeting a key gene-frizzled receptor 3 (FZD3) in the Wnt signaling pathway.

RESULTS

The Wnt pathway receptor FZD3 is upregulated in CRC along with other pathway genes, which play a critical role in tumorigenesis. In contrast, miR-98-5p inhibits the activity of FZD3 by binding directly to the 3'UTR of its mRNA, therefore exerting a suppressor effect on colorectal tumors.

CONCLUSION

The study reveals miR-98-5p as a novel target of FZD3 and an inhibitor of the Wnt signaling pathway hence being a potential candidate for developing targeted therapies against CRC.

miRNAs as cornerstones in chronic lymphocytic leukemia pathogenesis and therapeutic resistance- An emphasis on the interaction of signaling pathways

Chronic lymphocytic leukemia (CLL) accounts for the vast majority of cases of leukemia. Patients of advanced age are more likely to develop the condition, which has a highly varied clinical course. Consideration of illness features and preceding treatment sequence, as well as patient preferences and comorbidities, is necessary for selecting the appropriate treatment for the appropriate patient. Therefore, there is an urgent need for novel biomarkers with high sensitivity and specificity to detect CLL early, monitor CLL patients, select the treatment responders, and reduce ineffective treatment, unwanted side effects, and unnecessary expenses. In both homeostasis and illness, microRNAs (miRNAs/miRs) play a vital role as master regulators of gene expression and, by extension, protein expression. MiRNAs typically reduce the stability of mRNAs, including those encoding genes involved in tumorigenesis processes as cell cycle regulation, inflammation, stress response, angiogenesis, differentiation, apoptosis, and invasion. Due to their unique properties, miRNAs are rapidly being exploited as accurate biomarkers for illness detection, and medicines based on miRNA targets are finding widespread application in clinical practice. Accordingly, the current review serves as a quick primer on CLL and the biogenesis of miRNAs. In addition to providing a brief overview of the miRNAs whose function in the progression of CLL has been established by recent in vitro or in vivo research through articulating the influence of these miRNAs on a wide variety of cellular functions, including increased proliferative potential; support for angiogenesis; cell cycle aberration; evasion of apoptosis; promotion of metastasis; and reduced sensitivity to specific treatments.

Overexpressions of RHOA, CSNK1A1, DVL2, FZD8, and LRP5 genes enhance gastric cancer development in the presence of Helicobacter pylori

BACKGROUND AND STUDY AIMS

Intestinal metaplasia (IM), and Helicobacter pylori (HP) infection can be shown as risk factors in the development of gastric cancer (GC). WNT signaling pathway plays a critical role in carcinogenesis. However, the literature studies are limited on the significance of this pathway for the transition from IM to GC.

PATIENTS AND METHODS

We aimed to investigate the importance of the genes of WNT signaling pathways diagnostic and prognostic markers in the presence and absence of HP in conversion from IM to GC. 104 patients, (GC group n = 35, IM group n = 45, control group n = 25) were included in this case-control study. Expression of genes in WNT signalling were searched in study groups with qRT-PCR array and qRT-PCR method. Data were analysed using PCR array data analysis software.

RESULTS

Statistically significant overexpression of RHOA, CSNK1A1, DVL2, FZD8 and LRP5 genes was detected in the GC and IM groups compared to the control group (p < 0.05). Statistically significant overexpression of RHOA, CSNK1A1, DVL2, FZD8 and LRP5 genes was observed in patients with metastatic GC compared to patients with GC without metastasis (p < 0.05). It was found that the RHOA, CSNK1A1, DVL2, FZD8 and LRP5 genes were statistically significantly over-expressed in diffuse GC patients compared to non-diffuse GC patients (p < 0.05). Statistically significant overexpression of RHOA, CSNK1A1, DVL2, FZD8 and LRP5 genes was detected in HP positive IM patients compared to HP negative IM patients (p < 0.05).

CONCLUSION

Overexpression of RHOA, CSNK1A1, DVL2, FZD8 and LRP5 genes in IM may suggest that these genes are important markers in the development of IM and inflammation with HP. In addition, these genes are linked to tumor burden in the GC group. Consequently, we can conclude that these genes are poor prognosis biomarkers for GC and have the potential to be used as markers for future treatment monitoring.

Identification of therapeutic targets and prognostic biomarkers among frizzled family genes in glioma

Background: The biological functions of the Frizzled gene family (FZDs), as the key node of wingless-type MMTV integration site family (Wnt) and mammalian target of rapamycin signaling pathways, have not been fully elucidated in glioma. This study aims to identify novel therapeutic targets and prognostic biomarkers for gliomas, which may help us understand the role of FZDs. Methods: RNA-sequence data were downloaded from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) projects. Survival analyses, Cox regression analyses, nomograms, calibration curves, receiver operating characteristic (ROC) curves, gene function enrichment analyses, and immune cell infiltration analyses were conducted using R. Results: High expressions of FZDs were positively associated with the activation of mTOR signaling. FZD1/2/3/4/5/7/8 was significantly highly expressed in tumor tissues, and the high expression of FZD1/2/5/6/7/8 was significantly positively associated with poorer prognosis. FZD2 and FZD6 positively served as independent predictors of poor prognosis. Gene function analysis showed that FZDs were associated with mTOR signaling, immune response, cytokine-cytokine receptor interaction, extracellular matrix organization, apoptosis, and p53 signaling pathway. Conclusions: Our finding strongly indicated a crucial role of FZDs in glioma. FZD1/2/5/6/7/8 could be an unfavorable prognostic factor in glioma and FZD2 and FZD6 may be novel independent predictors of poor prognosis in glioma.

Regulatory role of miRNAs in Wnt signaling pathway linked with cardiovascular diseases

MicroRNAs (miRNAs) are discovered in science about 23 years ago. These are short, a series of non-coding, single-stranded and evolutionary conserved RNA molecules found in eukaryotic cells. It involved post-transcriptional fine-tune protein expression and repressing the target of mRNA in different biological processes. These miRNAs binds with the 3'-UTR region of specific mRNAs to phosphorylate the mRNA degradation and inhibit the translation process in various tissues. Therefore, aberrant expression in miRNAs induces numerous cardiovascular diseases and developmental defects. Subsequently, the miRNAs and Wnt singling pathway are regulating a cellular process in cardiac development and regeneration, maintain the homeostasis and associated heart diseases. In Wnt signaling pathway majority of the signaling components are expressed and regulated by miRNAs, whereas the inhibition or dysfunction of the Wnt signaling pathway induces cardiovascular diseases. Moreover, inadequate studies about the important role of miRNAs in heart development and diseases through Wnt signaling pathway has been exist still now. For this reason in present review we summarize and update the involvement of miRNAs and the role of Wnt signaling in cardiovascular diseases. We have discussed the mechanism of miRNA functions which regulates the Wnt components in cellular signaling pathway. The fundamental understanding of Wnt signaling regulation and mechanisms of miRNAs is quite essential for study of heart development and related diseases. This approach definitely enlighten the future research to provide a new strategy for formulation of novel therapeutic approaches against cardiovascular diseases.

Importance of clitellar tissue in the regeneration ability of earthworm Eudrilus eugeniae

Among the annelids, earthworms are renowned for their phenomenal ability to regenerate the lost segments. The adult earthworm Eudrilus eugeniae contains 120 segments and the body segments of the earthworm are divided into pre-clitellar, clitellar and post-clitellar segments. The present study denoted that clitellum plays vital role in the successful regeneration of the species. We have performed histological studies to identify among the three skin layers of the earthworm, which cellular layer supports the blastema formation and regeneration of the species. The histological evidences denoted that the proliferation of the longitudinal cell layer at the amputation site is crucial for the successful regeneration of the earthworm and it takes place only in the presence of an intact clitellum. Besides we have performed clitellar transcriptome analysis of the earthworm Eudrilus eugeniae to monitor the key differentially expressed genes and their associated functions and pathways controlling the clitellar tissue changes during both anterior and posterior regeneration of the earthworm. A total of 4707 differentially expressed genes (DEGs) were identified between the control clitellum and clitellum of anterior regenerated earthworms and 4343 DEGs were detected between the control clitellum and clitellum of posterior regenerated earthworms. The functional enrichment analysis confirmed the genes regulating the muscle mass shape and structure were significantly downregulated and the genes associated with response to starvation and anterior-posterior axis specification were significantly upregulated in the clitellar tissue during both anterior and posterior regeneration of the earthworm. The RNA sequencing data of clitellum and the comparative transcriptomic analysis were helpful to understand the complex regeneration process of the earthworm.

Exploring the Wnt Pathway as a Therapeutic Target for Prostate Cancer

Aberrant activation of the Wnt pathway is emerging as a frequent event during prostate cancer that can facilitate tumor formation, progression, and therapeutic resistance. Recent discoveries indicate that targeting the Wnt pathway to treat prostate cancer may be efficacious. However, the functional consequence of activating the Wnt pathway during the different stages of prostate cancer progression remains unclear. Preclinical work investigating the efficacy of targeting Wnt signaling for the treatment of prostate cancer, both in primary and metastatic lesions, and improving our molecular understanding of treatment responses is crucial to identifying effective treatment strategies and biomarkers that help guide treatment decisions and improve patient care. In this review, we outline the type of genetic alterations that lead to activated Wnt signaling in prostate cancer, highlight the range of laboratory models used to study the role of Wnt genetic drivers in prostate cancer, and discuss new mechanistic insights into how the Wnt cascade facilitates prostate cancer growth, metastasis, and drug resistance.

The Prognostic Value of the Developmental Gene FZD6 in Young Saudi Breast Cancer Patients: A Biomarkers Discovery and Cancer Inducers OncoScreen Approach

Wnt signalling receptors, Frizzleds (FZDs), play a pivotal role in many cellular events during embryonic development and cancer. Female breast cancer (BC) is currently the worldwide leading incident cancer type that cause 1 in 6 cancer-related death. FZD receptors expression in cancer was shown to be associated with tumour development and patient outcomes including recurrence and survival. FZD6 received little attention for its role in BC and hence we analysed its expression pattern in a Saudi BC cohort to assess its prognostic potential and unravel the impacted signalling pathway. Paraffin blocks from approximately 405 randomly selected BC patients aged between 25 and 70 years old were processed for tissue microarray using an automated tissue arrayer and then subjected to FZD6 immunohistochemistry staining using the Ventana platform. Besides, Ingenuity Pathway Analysis (IPA) knowledgebase was used to decipher the upstream and downstream regulators of FZD6 in BC. TargetScan and miRabel target-prediction databases were used to identify the potential microRNA to regulate FZD6 expression in BC. Results showed that 60% of the BC samples had a low expression pattern while 40% showed a higher expression level. FZD6 expression analysis showed a significant correlation with tumour invasion (p < 0.05), and borderline significance with tumour grade (p = 0.07). FZD6 expression showed a highly significant association with the BC patients’ survival outcomes. This was mainly due to the overall patients’ cohort where tumours with FZD6 elevated expression showed higher recurrence rates (DFS, p < 0.0001, log-rank) and shorter survival times (DSS, p < 0.02, log-rank). Interestingly, the FZD6 prognostic value was more potent in younger BC patients as compared to those with late onset of the disease. TargetScan microRNA target-prediction analysis and validated by miRabel showed that FZD6 is a potential target for a considerable number of microRNAs expressed in BC. The current study demonstrates a potential prognostic role of FZD6 expression in young BC female patients and provides a better understanding of the involved molecular silencing machinery of the Wnt/FZD6 signalling. Our results should provide a better understanding of FZD6 role in BC by adding more knowledge that should help in BC prevention and theranostics.

miR-520a-5p regulates Frizzled 9 expression and mediates effects of cigarette smoke and iloprost chemoprevention

Expression of Frizzled 9 (FZD9) is critical to the activity of the lung cancer chemoprevention agent and prostacyclin analogue, iloprost. FZD9 is required in lung epithelial cells for iloprost to activate peroxisome proliferator activated receptor gamma (PPARG) and related anti-tumor signaling. We aimed to investigate which miRNA regulate FZD9 in the context of cigarette smoke exposure and iloprost treatment. We found that miR-520a-5p binds the FZD9 3’UTR in lung cell lines and alters activity and expression of FZD9 downstream targets. Cigarette smoke condensate (CSC) increases expression of miR-520a-5p, while iloprost decreases expression. Cancer promoting effects of a miR-520a-5p mimic were rescued with iloprost treatment, and effects of cigarette smoke were partially rescued with a miR-520a-5p inhibitor. Here we confirm miR-520a-5p as a regulator of FZD9 activity and a mediator of CSC and iloprost effects in the lung. Targeting miR-520a-5p could be an approach to restoring FZD9 expression and improving response to iloprost lung cancer chemoprevention.

Role of Frizzled receptor expression on patients' survival with gastrointestinal cancers: A systematic review with meta-analysis

BACKGROUND

Frizzled receptors (FZD) play a pivotal role in the initiation and progression of a wide array of cancers. Dysregulated expression of FZD receptors is correlated with higher metastasis and invasive potential, as well as short survival in many malignancies. In this meta-analysis, we aimed to verify the prognostic value of FZD receptor expression on patients' survival with different types of gastrointestinal (GI) cancers, including gastric, colorectal, and esophageal cancers.

METHODS

A systematic search was performed using PubMed, Scopus, and Web of Science from 2000 to November 2020. Fourteen studies, including 2997 patients met our inclusion criteria, in which nine articles were considered FZD7 while the rest were about other FZD members. The fixed-effect model was used to estimate the pooled hazard ratio (HR) and the 5-year overall survival (OS) rate. We used the Newcastle-Ottawa scale of cohort articles to determine the quality of included studies.

RESULTS

The results showed that high expression of FZD receptors is associated with the poor survival in patients with GI cancers (HR= 1.83, 95% CI: 1.5-2.17). Moreover, multivariate analysis indicated that FZD receptors could be considered as an independent prognostic factor (HR = 1.76, 95% CI: 1.37-2.16).

CONCLUSION

According to our results, overexpression of FZD receptors predicts a poor prognosis in patients with GI cancers and could be used as a useful therapeutic target.

FBXO17 Inhibits the Wnt/β-Catenin Pathway and Proliferation of Ishikawa Cells

Uterine corpus endometrial carcinoma (UCEC) is one of the most common types of cancer in women, and the incidence is rapidly increasing. Studies have shown that various signaling pathways serve crucial roles in the tumorigenesis of UCEC, amongst which the Wnt/β-catenin pathway is of great interest due to its crucial role in cell proliferation and the huge potential as a therapeutic target. In the present study, it was shown that FBXO17, which is a member of the F-box family, is abnormally downregulated in UCEC tissues compared with non-tumor endometrial tissues, and this was significantly associated with the clinical histological grade, as well as the abnormal proliferation of the UCEC cell line, Ishikawa, both in vitro and in vivo. Besides, the results suggested that FBXO17 may inhibit the Wnt/β-catenin signaling pathway and influence the expression of adhesion molecules, such as E-cadherin and N-cadherin in Ishikawa cells. In conclusion, these findings indicate that FBXO17 is a novel inhibitor of endometrial tumor development and it likely exerts effects via regulation of the Wnt signaling pathway.

MicroRNA-1 Modulates Chondrocyte Phenotype by Regulating FZD7 of Wnt/ β-Catenin Signaling Pathway

OBJECTIVE

Osteoarthritis (OA) is an incurable joint disease characterized by pronounced pain. MicroRNAs constitute epigenetic mechanisms that may affect OA progression by contributing to changes in chondrocyte phenotype. This study investigates for the first time whether there is a link between miRNA-1 (miR-1) and OA pathogenesis, and the molecular mechanisms involved.

DESIGN

OA-associated gene expression, including MMP-13, ADAMTS5, and COL2A1 was compared in chondrocytes from non-OA and OA cartilage, and in SW1353 cells over- and underexpressing miR-1. Bioinformatics and luciferase reporter assay were conducted to confirm whether FZD7 was a target of miR-1. The effects of miR-1 on FZD7 expression and downstream Wnt/β-catenin signalling were investigated.

RESULTS

Non-OA and OA chondrocytes differed significantly in the expression of miR-1 and OA-associated genes. MiR-1 over- and underexpression in SW1353 cells, respectively, reduced and enhanced gene expression associated with cartilage catabolism. FZD7, which has an important role in the Wnt/β-catenin signaling pathway, was shown to be a potential target of miR-1. MiR-1 binding to FZD7 increased the levels of phosphorylated (inactivated) β-catenin, thereby preventing downstream β-catenin signaling.

CONCLUSIONS

Inhibition of Wnt/β-catenin signaling by miR-1 in chondrocytes may attenuate the expression of genes that regulate the activity of catabolic enzymes. This finding may be useful for future investigations of molecular targets for OA treatment.

Analysis of exosome-derived microRNAs reveals insights of intercellular communication during invasion of breast, prostate and glioblastoma cancer cells

MiRNAs represent a mechanism that regulates gene expression in many pathological conditions. Exosomes are known to be secreted from all types of cells, and the exosomes-released molecules are crucial messengers that can regulate cellular processes. We investigated the miRNAs content of exosomes released by cancer cells during the invasion . An invasion stimulus has been generated through scratches created on the confluent cells of cancer cell lines: glioblastoma, breast and prostate cancers.Several miRNAs were found to be significantly differentially abundant during the cell invasion , both in common among different cell lines and exclusive. Understanding the language codes among cells involved in invasion can lead to the development of therapies that can inhibit cellular communication, slowing or eventually stopping their activity.

Circ-ACAP2 facilitates the progression of colorectal cancer through mediating miR-143-3p/FZD4 axis

BACKGROUND

Circular RNAs (circRNAs) play crucial roles in multiple cancers, including colorectal cancer (CRC). Here, we explored the role of circRNA ArfGAP with coiled-coil, ankyrin repeat and PH domains 2 (circ-ACAP2) in the progression and radioresistance of CRC.

METHODS

Quantitative real-time polymerase chain reaction (qPCR) and Western blot assay were used to detect RNA and protein expression, respectively. The proliferation, apoptosis, migration, invasion and radioresistance of CRC cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, transwell migration assay, transwell invasion assay and colony formation assay. The target interaction between microRNA-143-3p (miR-143-3p) and circ-ACAP2 or frizzled class receptor 4 (FZD4) was verified by dual-luciferase reporter assay. Murine xenograft model was established to explore the role of circ-ACAP2 in vivo.

RESULTS

The expression of circ-ACAP2 was prominently enhanced in CRC tissues and cell lines. Circ-ACAP2 facilitated the proliferation, migration, invasion and radioresistance whereas inhibited the apoptosis of CRC cells. MiR-143-3p was a direct target of circ-ACAP2 in CRC cells. Circ-ACAP2 promoted the progression and radioresistance of CRC partly by sponging miR-143-3p. MiR-143-3p interacted with the 3' untranslated region (3'UTR) of FZD4 in CRC cells, and FZD4 overexpression partly reversed miR-143-3p-mediated effects in CRC cells. Wnt/β-catenin signalling was modulated by circ-ACAP2/miR-143-3p/FZD4 axis in CRC cells.

CONCLUSION

Circ-ACAP2 contributed to the development and radioresistance of CRC partly through targeting miR-143-3p/FZD4 axis, which provided novel potential diagnostic and therapeutic targets for CRC.

Exosome Released FZD10 Increases Ki-67 Expression via Phospho-ERK1/2 in Colorectal and Gastric Cancer

Frizzled (FZD) proteins are primary receptors for Wnt signaling that activates the mitogen-activated protein kinase (MAPK) pathways. Dysfunction of Wnt signals with consequently abnormal activation of MAPK3 pathways was found in colorectal cancer (CRC) and gastric cancer (GC). Upregulation of FZD10 protein, localized in the exosomes isolated from plasma of CRC and GC patients, was associated with a poor prognosis. Herein, the expression levels of circulating FZD10 were found to be strongly correlated to their expression levels in the corresponding tissues in CRC and GC patients. Bioinformatic prediction revealed a link between FZD10 and Ki-67 through MAPK3. In both CRC and GC tissues, pERK1/2 levels were significantly increased at more advanced disease stages, and pERK1/2 and Ki-67 were correlated. Silencing of FZD10 in CRC and GC cells resulted in a significant reduction of pERK1/2 and Ki-67 expression, while subsequent treatment with exogenous exosomes partially restored their expression levels. The strong correlation between the expression of Ki-67 in tissues and of FZD10 in exosomes suggests that the exosome-delivered FZD10 may be a promising novel prognostic and diagnostic biomarker for CRC and GC.

Gene network analysis using SWIM reveals interplay between the transcription factor-encoding genes HMGA1, FOXM1, and MYBL2 in triple-negative breast cancer

Among breast cancer subtypes, triple-negative breast cancer (TNBC) is the most aggressive with the worst prognosis and the highest rates of metastatic disease. To identify TNBC gene signatures, we applied the network-based methodology implemented by the SWIM software to gene expression data of TNBC patients in The Cancer Genome Atlas (TCGA) database. SWIM enables to predict key (switch) genes within the co-expression network, whose perturbations in expression pattern and abundance may contribute to the (patho)biological phenotype. Here, SWIM analysis revealed an interesting interplay between the genes encoding the transcription factors HMGA1, FOXM1, and MYBL2, suggesting a potential cooperation among these three switch genes in TNBC development. The correlative nature of this interplay in TNBC was assessed by in vitro experiments, demonstrating how they may actually modulate the expression of each other.

Expression analysis of chick Frizzled receptors during spinal cord development

Frizzleds (Fzds) are transmembrane receptors that can transduce signals dependent upon binding of Wnts, a large family of secreted glycoproteins homologous to the Drosophila wingless gene. FZDs are critical for a wide variety of normal and pathological developmental processes. In the nervous system, Wnts and Frizzleds play an important role in anterior-posterior patterning, cell fate decisions, proliferation, and synaptogenesis. Here, we preformed a comprehensive expression profile of Wnt receptors (FZD) by using situ hybridization to identify FZDs that are expressed in dorsal-ventral regions of the neural tube development. Our data show specific expression for FZD1,2,3,7,9 and 10 in the chick developing spinal cord. This expression profile of cFZD receptors offers the basis for functional studies in the future to determine roles for the different FZD receptors and their interactions with Wnts during dorsal-ventral neural tube development in vivo. Furthermore, we also show that co-overexpression of Wnt1/3a by in vivo electroporation affects FZD7/10 expression in the neural tube. This illustrates an example of Wnts-FZDs interactions during spinal cord neurogenesis.

Targeting Oncogenic WNT Signalling with WNT Signalling-Derived Peptides

WNT signalling is known to be a crucial regulator of embryonic development and tissue homeostasis. Aberrant expression of WNT signalling elements or their mutations has been implicated in carcinogenesis and/or the progression of several different cancer types. Investigations of how WNT signalling affects carcinogenesis and cancer progression have revealed that it has essential roles in the regulation of proliferation, apoptosis, and cancer stemness and in angiogenesis and metastasis. Consequently, WNT-targeted therapy has gained much attention and has resulted in the development of several small molecules, the majority of which act as inhibitors of different WNT signalling events. However, although numerous inhibitory WNT signalling drug candidates have been included in clinical trials, no significant breakthroughs have been made. This could possibly be due to problems with inefficient binding to the target, compensatory signalling mechanisms and toxicity towards normal cells. Therapeutic peptides targeting WNT signalling in cancer cells have been developed as an alternative approach, with the hope that they might overcome the limitations reported for small WNT inhibitory molecules. In this chapter, we describe recent developments made in the design and characterization of WNT signalling-derived peptides aiming at their use as alternative cancer therapeutics and/or combined adjuvant therapy to conventional therapies.

An In Silico Analysis Identified FZD9 as a Potential Prognostic Biomarker in Triple-Negative Breast Cancer Patients

OBJECTIVE

Breast cancer (BC) is the main cause of cancer-related deaths in women across the world. It can be classified into different subtypes, including triple-negative (TN), which is characterized by the absence of hormone receptors for estrogen and progesterone and the lack of the human epidermal growth factor receptor 2. These tumors have high heterogeneity, acquire therapeutic resistance, and have no established target-driven treatment yet. The identification of differentially expressed genes in TN breast tumors and the in silico validation of their prognostic role in these tumors.

MATERIALS AND METHODS

We employed a microarray dataset and, by using the GEO2R tool, we identified a list of differentially expressed genes. The in silico validation was conducted using several online platforms including the KM Plotter, cBioPortal, bc-GenExMiner, Prognoscan, and Roc Plotter.

RESULTS

We observed that FZD9 was among the top differentially expressed genes in a cohort of patients with different TNBC subtypes. The FZD9 expression was significantly different in TN breast tumors than in non-TN (nTN) breast tumors (p<0.0001), and the basal TN subtype showed the highest levels (p<0.0001). In addition, the FZD9 levels were significantly inversely and positively proportional (p<0.0001) to estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2 clinical parameters. The high levels of FZD9 were associated with worse overall survival (p=0.007), relapse-free survival (p=5.8e-05), and worse survival in patients who received chemotherapy (p=3.2e-05; 0.007).

CONCLUSION

Our cumulative results demonstrated that FZD9 plays an important role in TNBC and may be a potential prognostic biomarker. Nevertheless, further in vitro and in vivo assays are necessary to confirm our findings and to strengthen the evidences about the mechanisms by which FZD9 functions in these tumors.

Zooming in on the WNT/CTNNB1 Destruction Complex: Functional Mechanistic Details with Implications for Therapeutic Targeting

WNT/CTNNB1 signaling is crucial for balancing cell proliferation and differentiation in all multicellular animals. CTNNB1 accumulation is the hallmark of WNT/CTNNB1 pathway activation and the key downstream event in both a physiological and an oncogenic context. In the absence of WNT stimulation, the cytoplasmic and nuclear levels of CTNNB1 are kept low because of its sequestration and phosphorylation by the so-called destruction complex, which targets CTNNB1 for proteasomal degradation. In the presence of WNT proteins, or as a result of oncogenic mutations, this process is impaired and CTNNB1 levels become elevated.Here we discuss recent advances in our understanding of destruction complex activity and inactivation, focusing on the individual components and interactions that ultimately control CTNNB1 turnover (in the "WNT off" situation) and stabilization (in the "WNT on" situation). We especially highlight the insights gleaned from recent quantitative, image-based studies, which paint an unprecedentedly detailed picture of the dynamic events that control destruction protein complex composition and function. We argue that these mechanistic details may reveal new opportunities for therapeutic intervention and could result in the destruction complex re-emerging as a target for therapy in cancer.

MicroRNAs in the Migration of Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) represent a promising source of cell-based therapies for treatment of a wide variety of injuries and diseases. Their tropism and migration to the damaged sites, which are elicited by cytokines secreted from tissues around pathology, are the prerequisite for tissue repair and regeneration. Better understanding of the elicited-migration of MSCs and discovering conditions that elevate their migration ability, will help to increase their homing to pathologies and improve therapeutic efficacy. It is increasingly recognized that microRNAs are important regulators of cell migration. Here we summarize current understanding of the microRNA-regulated migration of MSCs.

Concurrent Wnt pathway component expression in breast and colorectal cancer

Wnt signaling pathway regulates important cell functions such as proliferation and migration and is frequently deregulated in colorectal and breast cancer. Thus, it constitutes an attractive therapeutic target with many drugs being investigated in clinical trials. Eighty-two breast and 102 colorectal carcinomas were analyzed for: relative mRNA expression levels of Wnt pathway components namely Wnt3 ligand, Frizzled 7 receptor and LEF1 transcriptional factor, their concurrent expression patterns and their correlation with clinicopathological features. Regarding breast carcinomas, increased relative mRNA expression levels of WNT3 were found in 54 % of cases whereas decreased relative mRNA expression levels were observed in FZD7 and LEF1 in 82 % and 43 % of cases, respectively. Expression levels of WNT3 were significantly correlated with tumour grade (p = 0.021) in breast cancer. As far as colorectal carcinomas are concerned, increased relative mRNA expression levels of WNT3, FZD7 and LEF1 were found in 60 %, 37 % and 48 % of cases respectively. A statistically significant correlation emerged between LEF1expression levels and pT-category (p = 0.027), suggesting a possible association with tumour aggressiveness in colorectal carcinomas. Statistically significant linear correlations were observed between the expression of WNT3/LEF1 (R = 0.233, p = 0.035) and FZD7/LEF1 (R = 0.359, p = 0.001) in breast carcinomas as well as in colorectal carcinomas (R = 0.536, p < 0.01 and R = 0.210, p = 0.034) respectively. Our results demonstrate a possible clinical significance of Wnt pathway gene expression levels in both tumour types. The distinct expression patterns and simultaneous expression of the investigated genes underscore the complexity of this pathway in breast and colorectal carcinogenesis and highlights the necessity of patient selection with regard to the effectiveness of Wnt pathway inhibitors.

A digital mRNA expression signature to classify challenging Spitzoid melanocytic neoplasms

Spitzoid neoplasms are a challenging group of cutaneous melanocytic proliferations. They are characterized by epithelioid and/or spindle-shaped melanocytes and classified as benign Spitz nevi (SN), atypical Spitz tumors (AST), or malignant Spitz tumors (MST). The intermediate AST category represents a diagnostically challenging group since on purely histopathological grounds, their benign or malignant character remains unpredictable. This results in uncertainties in patient treatment and prognosis. The molecular properties of Spitzoid lesions, especially their transcriptomic landscape, remain poorly understood, and genomic alterations in melanoma-associated oncogenes are typically absent. The aim of this study was to characterize their transcriptome with digital mRNA expression profiling. Formalin-fixed paraffin-embedded samples (including 27 SN, 10 AST, and 14 MST) were analyzed using the NanoString nCounter PanCancer Pathways Panel. The number of significantly differentially expressed genes in SN vs. MST, SN vs. AST, and AST vs. MST was 68, 167, and 18, respectively. Gene set enrichment analysis revealed upregulation of pathways related to epithelial-mesenchymal transition and immunomodulatory-, angiogenesis-, hormonal-, and myogenesis-associated processes in AST and MST. A molecular signature of SN vs. MST was discovered based on the top-ranked most informative genes: NRAS, NF1, BMP2, EIF2B4, IFNA17, and FZD9. The AST samples showed intermediate levels of the identified signature. This implies that the gene signature can potentially be used to distinguish high-grade from low-grade AST with a larger study cohort in the future. This combined histopathological and transcriptomic methodology is promising for prospective diagnostics of Spitzoid neoplasms and patient management in dermatological oncology.

Interaction between miRNAs and signaling cascades of Wnt pathway in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL), a severe problem all over the world and represents around 25% of all total leukemia cases, is generating the need for novel targets against CLL. Wnt signaling cascade regulates cell proliferation, differentiation, and cell death processes. Thus, any alteration of the Wnt signaling pathway protein cascade might develop into various types of cancers, either by upregulation or downregulation of the Wnt signaling pathway protein components. In addition, it is reported that activation of the Wnt signaling pathway is associated with the transcriptional activation of microRNAs (miRNAs) by binding to its promoter region, suggesting feedback regulation. Considering the protein regulatory functions of various miRNAs, they can be approached therapeutically as modulatory targets for protein components of the Wnt signaling pathway. In this article, we have discussed the potential role of miRNAs in the regulation of Wnt signaling pathway proteins related to the pathogenesis of CLL via crosstalk between miRNAs and Wnt signaling pathway proteins. This might provide a clear insight into the Wnt protein regulatory function of various miRNAs and provide a better understanding of developing advanced and promising therapeutic approaches against CLL.

Targeting Frizzled-7 Decreases Stemness and Chemotherapeutic Resistance in Gastric Cancer Cells by Suppressing Myc Expression

BACKGROUND Although the promoting roles of Frizzled-7 (Fzd7) have been shown before, its effects in gastric cancer (GC) cell stemness are still unclear. The present study assessed the effects of Fzd7 on GC cell stemness and chemoresistance. MATERIAL AND METHODS Clinical samples were used to detect Fzd7 expression and online datasets were used to analyze the correlation between Fzd7 expression and GC patient prognosis. Quantitative real-time PCR (qPCR), Western blot, and spheroid formation were used to detect the stemness of cells and Fzd7-mediated effects on GC cell stemness. Cell viability was assessed to evaluate the role of Fzd7 in chemoresistance of GC cells. RESULTS We found that the expression of Frizzled-7 (Fzd7), a Wnt receptor, was increased in gastric cancer (GC) cells and tissues. Additionally, Fzd7 expression was correlated with shorter overall survival of GC patients. Knockdown of Fzd7 or using inhibitors of Wnt/Fzd (OMP-18R5/Vantictumad) decreased GC cell stemness, characterized as a decrease of spheroid formation ability and expression of stemness regulators. Notably, Fzd7 knockdown or inhibitors of Wnt/Fzd attenuated the chemoresistance of GC cells. Furthermore, elevation of Myc expression rescued the effects of Fzd7 inhibition on GC cell stemness and chemoresistance. CONCLUSIONS Our results suggest that inhibition of Fzd7 decreases the stemness and chemotherapeutic resistance of GC cells.

Modulation of Calretinin Expression in Human Mesothelioma Cells Reveals the Implication of the FAK and Wnt Signaling Pathways in Conferring Chemoresistance towards Cisplatin

Malignant mesothelioma (MM) is an aggressive asbestos-linked neoplasm, characterized by dysregulation of signaling pathways. Due to intrinsic or acquired chemoresistance, MM treatment options remain limited. Calretinin is a Ca²⁺-binding protein expressed during MM tumorigenesis that activates the FAK signaling pathway, promoting invasion and epithelial-to-mesenchymal transition. Constitutive calretinin downregulation decreases MM cells’ growth and survival, and impairs tumor formation in vivo. In order to evaluate early molecular events occurring during calretinin downregulation, we generated a tightly controlled IPTG-inducible expression system to modulate calretinin levels in vitro. Calretinin downregulation significantly reduced viability and proliferation of MM cells, attenuated FAK signaling and reduced the invasive phenotype of surviving cells. Importantly, surviving cells showed a higher resistance to cisplatin due to increased Wnt signaling. This resistance was abrogated by the Wnt signaling pathway inhibitor 3289-8625. In various MM cell lines and regardless of calretinin expression levels, blocking of FAK signaling activated the Wnt signaling pathway and vice versa. Thus, blocking both pathways had the strongest impact on MM cell proliferation and survival. Chemoresistance mechanisms in MM cells have resulted in a failure of single-agent therapies. Targeting of multiple components of key signaling pathways, including Wnt signaling, might be the future method-of-choice to treat MM.

MicroRNA-206 attenuates glioma cell proliferation, migration, and invasion by blocking the WNT/β-catenin pathway via direct targeting of Frizzled 7 mRNA

Glioma is one of the most prevalent primary malignant brain tumours among adults, and accumulating evidence has shown that dysregulation of microRNAs (miRNAs) is associated with various types of cancers, including glioma. It is necessary to gain a better understanding of the roles and mechanisms of action of miRNAs in WNT-driven glioblastoma multiforme (GBM). Here, we report that miR-206 inhibits the WNT/β-catenin pathway by directly targeting Frizzled 7 (FZD7) mRNA and functions as a tumour suppressor in glioma. The expression of miR-206 in human glioma samples and glioma cells was assessed by reverse-transcription quantitative PCR, fluorescence in situ hybridisation, and histological analysis. Cell Counting Kit-8, colony formation, 5-ethynyl-2'-deoxyuridine incorporation, flow-cytometric, wound healing, Transwell invasion, and three-dimensional migration assays were performed to examine glioma cell proliferation, migration, and invasion in vitro. The effects of miR-206 in vivo were investigated in a xenograft nude-mouse model. MiR-206 expression was significantly lower in glioma specimens than in normal control samples. FZD7 was confirmed as a direct target gene of miR-206. GBM cell proliferation, migration, and invasion were blocked after restoration of miR-206 expression. Moreover, intracranial glioma models revealed an inhibitory effect of miR-206 on intracranial glioma tumour growth. Our results suggest that miR-206 plays a key role in the blockade of the WNT/β-catenin signalling pathway by down-regulating FZD7 and may be a promising therapeutic agent against malignant glioma and other WNT-driven tumours.

Effects of pericytes and colon cancer stem cells in the tumor microenvironment

Colorectal cancer (CRC) is one type of tumor with the highest frequency and mortality worldwide. Although current treatments increase patient survival, it is important to detect CRC in early stages; however, most CRC, despite responding favorably to treatment, develop resistance and present recurrence, a situation that will inevitably lead to death. In recent years, it has been shown that the main reason for drug resistance is the presence of colon cancer stem cells (CSC). Pericytes are also capable of tumor homing and are important cellular components of the tumor microenvironment (TME), contributing to the formation of vessels and promoting metastasis; however, they have not been considered very important as a therapeutic target in cancer. In this review, we highlight the contribution of pericytes and cancer stem cells to some classical hallmarks of cancer, namely, tumor angiogenesis, growth, metastasis, and evasion of immune destruction, and discuss therapies targeting pericytes and cancer stem cells in CRC.

Long noncoding RNA LINC00673-v4 promotes aggressiveness of lung adenocarcinoma via activating WNT/β-catenin signaling

This study uncovers a long noncoding RNA (lncRNA)-mediated mechanism underlying lung adenocarcinoma (LAD) metastasis. We here report that lncRNA LINC00673-v4 expression is up-regulated in LAD and is associated with disease progression. At the molecular level, LINC00673-v4 acts as a scaffold molecule that promotes the interaction between DDX3 and CK1ε and thus the phosphorylation of dishevelled, which subsequently activates WNT/β-catenin signaling and consequently causes aggressiveness of LAD. Treatment with antisense oligonucleotides against LINC00673-v4 strongly suppresses LAD metastasis in vivo.

It is well recognized that metastasis can occur early in the course of lung adenocarcinoma (LAD) development, and yet the molecular mechanisms driving this capability of rapid metastasis remain incompletely understood. Here we reported that a long noncoding RNA, LINC00673, was up-regulated in LAD cells. Of note, we first found that LINC00673-v4 was the most abundant transcript of LINC00673 in LAD cells and its expression was associated with adverse clinical outcome of LAD. In vitro and in vivo experiments demonstrated that LINC00673-v4 enhanced invasiveness, migration, and metastasis of LAD cells. Mechanistically, LINC00673-v4 augmented the interaction between DDX3 and CK1ε and thus the phosphorylation of dishevelled, which subsequently activated WNT/β-catenin signaling and consequently caused aggressiveness of LAD. Antagonizing LINC00673-v4 suppressed LAD metastasis in vivo. Together, our data suggest that LINC00673-v4 is a driver molecule for metastasis via constitutively activating WNT/β-catenin signaling in LAD and may represent a potential therapeutic target against the metastasis of LAD.

Upregulated RACK1 attenuates gastric cancer cell growth and epithelial-mesenchymal transition via suppressing Wnt/β-catenin signaling

Purpose: As there have been few studies on the effects of the receptor for activated C kinase 1 (RACK1) on gastric cancer (GC), we aimed to explore such effects and the mechanism that may be involved.

Patients and methods: Normal gastric epithelial cells and six GC cell lines were used to detect the mRNA expression of RACK1. Overexpressing RACK1 was transfected in HGC27 and MGC803 cells. The effects of overexpressing RACK1 on cell viability, migration, and invasion were determined by cell counting kit-8, wound scratch, and Transwell assay, respectively. The expressions of epithelial–mesenchymal transition (EMT) and Wnt/β-catenin signaling related genes were detected using quantitative real-time PCR or Western blot. Wnt pathway agonist LiCl was added into RACK1 overexpressing GC cells, and then cell viability, migration, and invasion were also detected.

Results: RACK1 was downregulated in GC cell lines. Under the circumstance that overexpressing RACK1 was successfully transfected in the two lowest RACK1-expressing GC cells, significant inhibition of cell viability, migration, and invasion, promotion to the mRNA and protein expression of E-cadherin, as well as a decrease in the N-cadherin and Snail expressions could be observed. Overexpressing RACK1 also enhanced the protein level of phosphorylation-β-catenin/β-catenin and attenuated c-Jun protein expression. Additionally, LiCl could partially reverse the inhibitory effects of cell viability, migration and invasion by overexpressing RACK.

Conclusion: We found RACK1 possibly inhibited epithelial–mesenchymal transition of GC cells through limitation of the Wnt/β-catenin pathway, thereby suppressing cell migration and invasion; RACK1 could also suppress cell growth.

CD82 supports survival of childhood acute myeloid leukemia cells via activation of Wnt/β-catenin signaling pathway

BACKGROUND

Stem cell marker CD82 plays a vital role in the oncogenesis and progression of acute myelogenous leukemia (AML), especially in sharing properties of leukemia stem cells (LSCs). The Wnt/β-catenin pathway is required for the development of LSCs in AML. The present study aimed to validate whether CD82 supports the survival of LSCs in pediatric AML via activation of Wnt/β-catenin signaling pathway.

METHODS

CD82 expression and its correlation with molecules downstream of Wnt/β-catenin pathway in samples from pediatric AML patients were analyzed. Forced or downregulated expression of CD82 in AML cells was evaluated for the effects of CD82 on cell proliferation, cycle regulation, apoptosis, and adriamycin chemoresistance and to validate the underlying mechanism.

RESULT

Aberrant expression of CD82 in pediatric AML patients was found. CD82 messenger RNA expression correlated positively with downstream molecules of Wnt/β-catenin pathway in AML children. Knockdown of CD82 induced apoptosis, suppressed growth, and decreased adriamycin chemoresistance in AML cells. CD82 accelerated β-catenin nuclear location and then stimulated the expression of downstream molecules of Wnt/β-catenin pathway.

CONCLUSION

CD82 regulates the proliferation and chemotherapy resistance of AML cells via activation of the Wnt/β-catenin pathway, which suggest that the CD82 may be a potential therapeutic target in AML children.

Structure-guided design fine-tunes pharmacokinetics, tolerability, and antitumor profile of multispecific frizzled antibodies

Aberrant activation of Wnt/β-catenin signaling occurs frequently in cancer. However, therapeutic targeting of this pathway is complicated by the role of Wnt in stem cell maintenance and tissue homeostasis. Here, we evaluated antibodies blocking 6 of the 10 human Wnt/Frizzled (FZD) receptors as potential therapeutics. Crystal structures revealed a common binding site for these monoclonal antibodies (mAbs) on FZD, blocking the interaction with the Wnt palmitoleic acid moiety. However, these mAbs displayed gastrointestinal toxicity or poor plasma exposure in vivo. Structure-guided engineering was used to refine the binding of each mAb for FZD receptors, resulting in antibody variants with improved in vivo tolerability and developability. Importantly, the lead variant mAb significantly inhibited tumor growth in the HPAF-II pancreatic tumor xenograft model. Taken together, our data demonstrate that anti-FZD cancer therapeutic antibodies with broad specificity can be fine-tuned to navigate in vivo exposure and tolerability while driving therapeutic efficacy.

Comparison of different functional prediction scores using a gene-based permutation model for identifying cancer driver genes

Background

Identifying cancer driver genes (CDG) is a crucial step in cancer genomic toward the advancement of precision medicine. However, driver gene discovery is a very challenging task because we are not only dealing with huge amount of data; but we are also faced with the complexity of the disease including the heterogeneity of background somatic mutation rate in each cancer patient. It is generally accepted that CDG harbor variants conferring growth advantage in the malignant cell and they are positively selected, which are critical to cancer development; whereas, non-driver genes harbor random mutations with no functional consequence on cancer. Based on this fact, function prediction based approaches for identifying CDG have been proposed to interrogate the distribution of functional predictions among mutations in cancer genomes (eLS 1–16, 2016). Assuming most of the observed mutations are passenger mutations and given the quantitative predictions for the functional impact of the mutations, genes enriched of functional or deleterious mutations are more likely to be drivers. The promises of these methods have been continually refined and can therefore be applied to increase accuracy in detecting new candidate CDGs. However, current function prediction based approaches only focus on coding mutations and lack a systematic way to pick the best mutation deleteriousness prediction algorithms for usage.

Results

In this study, we propose a new function prediction based approach to discover CDGs through a gene-based permutation approach. Our method not only covers both coding and non-coding regions of the genes; but it also accounts for the heterogeneous mutational context in cohort of cancer patients. The permutation model was implemented independently using seven popular deleteriousness prediction scores covering splicing regions (SPIDEX), coding regions (MetaLR, and VEST3) and pan-genome (CADD, DANN, Fathmm-MKL coding and Fathmm-MKL noncoding). We applied this new approach to somatic single nucleotide variants (SNVs) from whole-genome sequences of 119 breast and 24 lung cancer patients and compared the seven deleteriousness prediction scores for their performance in this study.

Conclusion

The new function prediction based approach not only predicted known cancer genes listed in the Cancer Gene Census (CGC), but also new candidate CDGs that are worth further investigation. The results showed the advantage of utilizing pan-genome deleteriousness prediction scores in function prediction based methods. Although VEST3 score, a deleteriousness prediction score for missense mutations, has the best performance in breast cancer, it was topped by CADD and Fathmm-MKL coding, two pan-genome deleteriousness prediction scores, in lung cancer.

Electronic supplementary material

The online version of this article (10.1186/s12920-018-0452-9) contains supplementary material, which is available to authorized users.

Overexpression of FZD1 is Associated with a Good Prognosis and Resistance of Sunitinib in Clear Cell Renal Cell Carcinoma

Frizzled class receptor 1 (FZD1), a receptor for Wnt signaling pathway. Overexpression of FZD1 has been detected in many cancer tissues and cells resulting in tumor development and drug resistance. However, its expression status and prognostic merit in renal cancer still remains unclear. We screened the FZD1 mRNA in clear cell renal cell carcinoma (ccRCC) and papillary renal cell carcinoma (pRCC) from TCGA database and Oncomine database. We then detected FZD1 mRNA expression in sunitinib-resistant cells and the corresponding parental cells by qRT-PCR. FZD1 level was significantly upregulated in renal cancer tissues, renal cancer cell lines and their corresponding sunitinib-resistant cells. FZD1 level was also associated with the clinicopathological characteristics of ccRCC patients that could discriminate metastasis, pathological stage, recurrence and prognosis in ccRCC patients. The Kaplan-Meier survival curve and the log-rank test revealed FZD1 was higher in lower clinical stage and grade that correlated with better overall survival (OS) and disease-free survival (DFS) in total and subgroups of ccRCC patients. Both univariate and multivariate cox regression analysis indicated that high FZD1 level was an independent predictor of good prognosis for OS (HR 0.569, P=0.001) and DFS (HR 0.559, P=0.036) in ccRCC patients. Using cBioportal program, less than 1% mutation in the patients with renal cancer was observed, the alterations in FZD1 were correlated with better OS (P=0.0404) in ccRCC patients. Finally, the result of KEGG pathway analysis predicted seven potential pathways that FZD1 and its related genes got involved in ccRCC, including Hippo signaling pathway. This indicated potential therapeutic targets of ccRCC. In conclusion, our results suggested that expression status of FZD1 had a diagnostic value and prognostic value in ccRCC patients, it also may serve as a potential drug target to relieve sunitinib resistance in renal cancer patients.

Frizzled-7 Is Required for Wnt Signaling in Gastric Tumors with and Without Apc Mutations

A subset of patients with gastric cancer have mutations in genes that participate in or regulate Wnt signaling at the level of ligand (Wnt) receptor (Fzd) binding. Moreover, increased Fzd expression is associated with poor clinical outcome. Despite these findings, there are no in vivo studies investigating the potential of targeting Wnt receptors for treating gastric cancer, and the specific Wnt receptor transmitting oncogenic Wnt signaling in gastric cancer is unknown. Here, we use inhibitors of Wnt/Fzd (OMP-18R5/vantictumab) and conditional gene deletion to test the therapeutic potential of targeting Wnt signaling in preclinical models of intestinal-type gastric cancer and ex vivo organoid cultures. Pharmacologic targeting of Fzd inhibited the growth of gastric adenomas in vivo. We identified Fzd7 to be the predominant Wnt receptor responsible for transmitting Wnt signaling in human gastric cancer cells and mouse models of gastric cancer, whereby Fzd7-deficient cells were retained in gastric adenomas but were unable to respond to Wnt signals and consequently failed to proliferate. Genetic deletion of Fzd7 or treatment with vantictumab was sufficient to inhibit the growth of gastric adenomas with or without mutations to Apc. Vantictumab is currently in phase Ib clinical trials for advanced pancreatic, lung, and breast cancer. Our data extend the scope of patients that may benefit from this therapeutic approach as we demonstrate that this drug will be effective in treating patients with gastric cancer regardless of APC mutation status. SIGNIFICANCE: The Wnt receptor Fzd7 plays an essential role in gastric tumorigenesis irrespective of Apc mutation status, therefore targeting Wnt/Fzd7 may be of therapeutic benefit to patients with gastric cancer.

Structural and dynamic characterization of human Wnt2-Fzd7 complex using computational approaches

Wnt and Frizzled (Fzd) family members play crucial roles in the self-renewal of tumor-initiating cells. Until now, only a few studies have addressed the distinct mechanism of Wnt-Fzd interactions. In this study, we suggest a possible interaction mode of Wnt2 with the Fzd7 cysteine-rich domain (CRD)-both of which are up-regulated in some types of cancer. A combination of homology modeling, molecular docking and molecular dynamics (MD) simulations was carried out to study this ligand-receptor complex in great detail. The results demonstrated the unique dynamic behavior of Wnt2 upon binding to Fzd7. Interestingly, the β-strand content of the C-terminal binding site of Wnt2 was obviously reduced when bound to Fzd7 CRD. Moreover, the N-terminal and C-terminal binding sites of Wnt2 appeared to interact with the C-terminal and N-terminal binding sites of Fzd7, respectively. Calculation of the binding energies uncovered the pivotal role of electrostatic and hydrophobic interactions in the binding of Wnt2 to Fzd7 CRD. In conclusion, this study provides valuable insights into the mechanism of the Wnt2-Fzd7 CRD interaction for application in colorectal cancer prevention programs. Graphical abstract Flowchart representation of different steps used in this study.