FZD7

Gene Summary

Gene:FZD7; frizzled class receptor 7
Aliases: FzE3
Location:2q33.1
Summary: Members of the 'frizzled' gene family encode 7-transmembrane domain proteins that are receptors for Wnt signaling proteins. The FZD7 protein contains an N-terminal signal sequence, 10 cysteine residues typical of the cysteine-rich extracellular domain of Fz family members, 7 putative transmembrane domains, and an intracellular C-terminal tail with a PDZ domain-binding motif. FZD7 gene expression may downregulate APC function and enhance beta-catenin-mediated signals in poorly differentiated human esophageal carcinomas. [provided by RefSeq, Jul 2008]
Databases:OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:frizzled-7
Source:NCBIAccessed: 01 September, 2019

Ontology:

What does this gene/protein do?
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Pathways:What pathways are this gene/protein implicaed in?
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Cancer Overview

Research Indicators

Publications Per Year (1994-2019)
Graph generated 01 September 2019 using data from PubMed using criteria.

Literature Analysis

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Tag cloud generated 01 September, 2019 using data from PubMed, MeSH and CancerIndex

Specific Cancers (5)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: FZD7 (cancer-related)

Xu H, Peng L, Shen M, et al.
Shiga-like toxin I exerts specific and potent anti-tumour efficacy against gastric cancer cell proliferation when driven by tumour-preferential Frizzled-7 promoter.
Cell Prolif. 2019; 52(3):e12607 [PubMed] Related Publications
OBJECTIVES: Tumour-targeted gene therapy is a promising approach for effective control of gastric cancer cell proliferation. Our study aims to develop a cancer therapy which combines tumour-targeting promoters with cytotoxins.
METHODS: The expression of globotriaosylceramide (Gb3), which is a Shiga-like toxin I (Stx1) receptor, was verified in gastric cancer compared with normal stomach tissues as assessed by flow cytometry and immunohistochemical analysis. We therefore constructed the recombinant pFZD7-Stx1 plasmid vectors with tumour-preferential Frizzled-7 promoter and Stx1. pFZD7-Stx1 was used to treat gastric cancer in vitro and in vivo. The gastric cancer cell proliferation and tumour growth were identified after the transfection with the pFZD7-Stx1.
RESULTS: Globotriaosylceramide was obviously increased in gastric cancer compared with normal stomach. The gastric cancer cell proliferation and tumour growth decreased significantly after the transfection with the pFZD7-Stx1.
CONCLUSION: Frizzled-7 promoter is preferentially active, and Gb3 is abundant in gastric cancer cells. Frizzled-7 promoter and Stx1 may be used to determine a novel and relatively specific and potent gastric cancer therapeutic strategy.

Götzel K, Chemnitzer O, Maurer L, et al.
In-depth characterization of the Wnt-signaling/β-catenin pathway in an in vitro model of Barrett's sequence.
BMC Gastroenterol. 2019; 19(1):38 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: An altered Wnt-signaling activation has been reported during Barrett's esophagus progression, but with rarely detected mutations in APC and β-catenin (CTNNB1) genes.
METHODS: In this study, a robust in-depth expression pattern analysis of frizzled receptors, co-receptors, the Wnt-ligands Wnt3a and Wnt5a, the Wnt-signaling downstream targets Axin2, and CyclinD1, as well as the activation of the intracellular signaling kinases Akt and GSK3β was performed in an in vitro cell culture model of Barrett's esophagus. Representing the Barrett's sequence, we used normal esophageal squamous epithelium (EPC-1, EPC-2), metaplasia (CP-A) and dysplasia (CP-B) to esophageal adenocarcinoma (EAC) cell lines (OE33, OE19) and primary specimens of squamous epithelium, metaplasia and EAC.
RESULTS: A loss of Wnt3a expression was observed beginning from the metaplastic cell line CP-A towards dysplasia (CP-B) and EAC (OE33 and OE19), confirmed by a lower staining index of WNT3A in Barrett's metaplasia and EAC, than in squamous epithelium specimens. Frizzled 1-10 expression analysis revealed a distinct expression pattern, showing the highest expression for Fzd2, Fzd3, Fzd4, Fzd5, Fzd7, and the co-receptor LRP5/6 in EAC cells, while Fzd3 and Fzd7 were rarely expressed in primary specimens from squamous epithelium.
CONCLUSION: Despite the absence of an in-depth characterization of Wnt-signaling-associated receptors in Barrett's esophagus, by showing variations of the Fzd- and co-receptor profiles, we provide evidence to have a significant role during Barrett's progression and the underlying pathological mechanisms.

Wang K, Li X, Song C, Li M
LncRNA AWPPH promotes the growth of triple-negative breast cancer by up-regulating frizzled homolog 7 (FZD7).
Biosci Rep. 2018; 38(6) [PubMed] Free Access to Full Article Related Publications

Quan H, Li B, Yang J
MicroRNA-504 functions as a tumor suppressor in hepatocellular carcinoma through inhibiting Frizzled-7-mediated-Wnt/β-catenin signaling.
Biomed Pharmacother. 2018; 107:754-762 [PubMed] Related Publications
Accumulating evidence suggests that microRNAs (miRNAs) are critical regulators in the development and progression of various malignant tumors, including hepatocellular carcinoma (HCC). Multiple findings have indicated that miRNA-504 (miR-504) is dysregulated in several types of cancers, functioning as an oncogenic miRNA or a tumor suppressive miRNA. However, the role of miR-504 in HCC remains unknown. In this study, we aimed to detect the expression pattern of miR-504 in HCC tissues and cell lines and investigate the precise biological function in HCC cells. Our results showed that miR-504 expression levels were frequently downregulated in both HCC tissues and cell lines. Gain-of-function experiments demonstrated that miR-504 overexpression inhibited the proliferation and invasion in HCC cell lines. By contrast, miR-504 inhibition had the opposite effect. Interestingly, bioinformatics analysis predicted that Frizzled-7 (FZD7) was a potential target gene of miR-504. Dual-luciferase reporter assays confirmed that miR-504 directly targeted the 3'-untranslated region of FZD7 mRNA. In addition, our results showed that miR-504 negatively regulated the mRNA and protein expression of FZD7 in HCC cell lines. Moreover, miR-540 overexpression inhibited the cellular expression of β-catenin and blocked the activation of Wnt signaling in HCC cells. Notably, restoration of FZD7 expression significantly reversed the inhibitory effect of miR-504 on proliferation, invasion, and Wnt/β-catenin signaling in HCC cells. In conclusion, our results demonstrate that miR-504 functions as a tumor suppressive miRNA that inhibits the proliferation and invasion of HCC cells by targeting FZD7 and inhibiting Wnt/β-catenin signaling. Our study provides evidence that miR-504-meidated FZD7/Wnt/β-catenin signaling pathway plays an important role in HCC development and progression and suggests miR-504 as a novel future therapeutic target for treatment of HCC.

Chen Z, Duan X
hsa_circ_0000177-miR-638-FZD7-Wnt Signaling Cascade Contributes to the Malignant Behaviors in Glioma.
DNA Cell Biol. 2018; 37(9):791-797 [PubMed] Related Publications
As a new member of the noncoding RNA family, circular RNAs (circRNAs) have been demonstrated as critical regulators in various physiological and pathological processes, such as tumorigenesis. However, the role of circRNAs has not been well understood until now. In our study, we found that circRNA hsa_circ_0000177 was upregulated in glioma tissues and cell lines. Also, hsa_circ_0000177 overexpression was associated with poor prognosis in glioma patients. Through functional experiments, we found that hsa_circ_0000177 knockdown dramatically inhibited glioma cell proliferation and invasion in vitro. Consistently, hsa_circ_0000177 knockdown significantly repressed glioma growth in vivo. In terms of mechanism, we used bioinformatics analysis and identified hsa_circ_0000177 as a miR-638 sponge. We showed that miR-638 inhibition could restore the proliferation and invasion of glioma cells transfected with hsa_circ_0000177 small interfering RNA. Furthermore, we demonstrated that frizzled class receptor 7 (FZD7) was targeted by miR-638 and upregulated by hsa_circ_0000177. Through upregulating FZD7 expression, hsa_circ_0000177 activated Wnt signaling and facilitated glioma growth. Taken together, our study revealed a novel signaling pathway involved in glioma progression.

Arzi L, Riazi G, Sadeghizadeh M, et al.
A Comparative Study on Anti-Invasion, Antimigration, and Antiadhesion Effects of the Bioactive Carotenoids of Saffron on 4T1 Breast Cancer Cells Through Their Effects on Wnt/β-Catenin Pathway Genes.
DNA Cell Biol. 2018; 37(8):697-707 [PubMed] Related Publications
Crocus sativus L. (saffron) has been used as a spice and as a medicine for the past four thousand years. Recently, saffron has been well documented to possess anticancer effects on primary tumors. However studies of its antimetastatic potential are lacking. The present study is a comparative investigation of the antimetastatic effects of saffron carotenoids, crocin and crocetin, on triple negative metastatic breast cancer cells (4T1) and their effects on the Wnt/β-catenin pathway. It was found that treatment of 4T1 cells with crocin and crocetin resulted in the inhibition of viability in a dose-dependent manner. Scratch and Transwell chamber assays showed that the nontoxic doses of crocin and crocetin significantly inhibited migration, cell mobility, and invasion, also attenuating adhesion to extracellular matrix. Crocin downregulated mRNA expression of FZD7, NEDD9, VIM, and VEGF-α genes and upregulated E-CAD. Crocin and crocetin exhibited comparable anti-invasion properties on 4T1 cells. However, crocin and crocetin exerted more pronounced antimigration and antiadhesion potency, respectively. Furthermore, we showed that the antimetastatic effects of crocin can occur through interfering with the Wnt/β-catenin pathway.

Katoh M
Multi‑layered prevention and treatment of chronic inflammation, organ fibrosis and cancer associated with canonical WNT/β‑catenin signaling activation (Review).
Int J Mol Med. 2018; 42(2):713-725 [PubMed] Free Access to Full Article Related Publications
β‑catenin/CTNNB1 is an intracellular scaffold protein that interacts with adhesion molecules (E‑cadherin/CDH1, N‑cadherin/CDH2, VE‑cadherin/CDH5 and α‑catenins), transmembrane‑type mucins (MUC1/CD227 and MUC16/CA125), signaling regulators (APC, AXIN1, AXIN2 and NHERF1/EBP50) and epigenetic or transcriptional regulators (BCL9, BCL9L, CREBBP/CBP, EP300/p300, FOXM1, MED12, SMARCA4/BRG1 and TCF/LEF). Gain‑of‑function CTTNB1 mutations are detected in bladder cancer, colorectal cancer, gastric cancer, liver cancer, lung cancer, pancreatic cancer, prostate cancer and uterine cancer, whereas loss‑of‑function CTNNB1 mutations are also detected in human cancer. ABCB1, ALDH1A1, ASCL2, ATF3, AXIN2, BAMBI, CCND1, CD44, CLDN1, CTLA4, DKK1, EDN1, EOMES, FGF18, FGF20, FZD7, IL10, JAG1, LEF1, LGR5, MITF, MSX1, MYC, NEUROD1, NKD1, NODAL, NOTCH2, NOTUM, NRCAM, OPN, PAX3, PPARD, PTGS2, RNF43, SNAI1, SP5, TCF7, TERT, TNFRSF19, VEGFA and ZNRF3 are representative β‑catenin target genes. β‑catenin signaling is involved in myofibroblast activation and subsequent pulmonary fibrosis, in addition to other types of fibrosis. β‑catenin and NF‑κB signaling activation are involved in field cancerization in the stomach associated with Helicobacter pylori (H. pylori) infection and in the liver associated with hepatitis C virus (HCV) infection and other etiologies. β‑catenin‑targeted therapeutics are functionally classified into β‑catenin inhibitors targeting upstream regulators (AZ1366, ETC‑159, G007‑LK, GNF6231, ipafricept, NVP‑TNKS656, rosmantuzumab, vantictumab, WNT‑C59, WNT974 and XAV939), β‑catenin inhibitors targeting protein‑protein interactions (CGP049090, CWP232228, E7386, ICG‑001, LF3 and PRI‑724), β‑catenin inhibitors targeting epigenetic regulators (PKF118‑310), β‑catenin inhibitors targeting mediator complexes (CCT251545 and cortistatin A) and β‑catenin inhibitors targeting transmembrane‑type transcriptional outputs, including CD44v6, FZD7 and LGR5. Eradicating H. pylori and HCV is the optimal approach for the first‑line prevention of gastric cancer and hepatocellular carcinoma (HCC), respectively. However, β‑catenin inhibitors may be applicable for the prevention of organ fibrosis, second‑line HCC prevention and treating β‑catenin‑driven cancer. The multi‑layered prevention and treatment strategy of β‑catenin‑related human diseases is necessary for the practice of personalized medicine and implementation of precision medicine.

Chen Z, Huang C, Ma T, et al.
Reversal effect of quercetin on multidrug resistance via FZD7/β-catenin pathway in hepatocellular carcinoma cells.
Phytomedicine. 2018; 43:37-45 [PubMed] Related Publications
BACKGROUND: Chemotherapy has been widely used to treat cancer, but the appearance of multidrug resistance (MDR) is the biggest obstacle to successful chemotherapy. One of the conventional mechanisms of MDR is overexpression of ATP-binding cassette (ABC) transporters such as P-glycoprotein (P-gp/ABCB1) and multidrug resistance-associated proteins (MRPs/ABCCs) that limits the prolonged and efficient use of chemotherapeutic drugs. To enhance the chemosensitivity of tumor cells, attentions have been focused on effective MDR modulators.
PURPOSE: This study aimed to investigate the reversal effect of quercetin on MDR, and explored its mechanism of action in vitro.
STUDY DESIGN/METHODS: The effect and mechanism of quercetin on MDR was examined by using MTT assay, flow cytometry, real-time PCR and western blot analysis in human hepatocellular carcinoma cells.
RESULTS: Our data found that the intracellular accumulation of rhodamine-123 (Rh123) and doxorubicin (ADR) were increased, the sensitivity of BEL/5-FU cells to chemotherapeutic drugs were increased, and the expressions of ABCB1, ABCC1 and ABCC2 were all down-regulated, which indicated that the functions and expressions of ABCB1, ABCC1 and ABCC2 efflux pump were inhibited by quercetin treatment. Moreover, the suppression of ABCB1, ABCC1 and ABCC2 by quercetin was dependent on the FZD7 through the Wnt/β-catenin pathway. Further research revealed that reduction of FZD7 by RNA interference (siFZD7) enhanced the sensitivity to chemotherapeutic drugs, increased the cellular accumulation of Rh123 and ADR, and induced inhibitory effects on the expression of FZD7, ABCB1, ABCC1, ABCC2 and β-catenin, similar to quercetin. In the meanwhile, overexpression of FZD7 showed the inversely effect on the expressions. Interesting, it was confirmed that quercetin could inhibit the expression levels of FZD7, ABCB1, ABCC1, ABCC2 and β-catenin in BEL-7402 cells; furthermore, treatment by quercetin combined with siFZD7 in BEL/5-FU cells, the expressions of these genes were effectively decreased in comparison to quercetin combined with siRNA negative control (sncRNA).
CONCLUSION: Overall, these data suggested the effectiveness of using quercetin, at least in part, via inhibiting FZD7 to combat chemoresistance and showed that quercetin could be developed into an efficient natural sensitizer for resistant human hepatocellular carcinoma.

Li G, Su Q, Liu H, et al.
Frizzled7 Promotes Epithelial-to-mesenchymal Transition and Stemness Via Activating Canonical Wnt/β-catenin Pathway in Gastric Cancer.
Int J Biol Sci. 2018; 14(3):280-293 [PubMed] Free Access to Full Article Related Publications
Aberrant activation of Wnt signaling is a crucial event in tumor development and metastasis. Wnt signaling is commonly divided into canonical and non-canonical signaling pathways based on whether β-catenin is activated (canonical). The two signaling pathways are initiated by Wnt ligand binding to the surface Frizzled (FZD) receptors, and regulate cancer stem cell self-renewal and epithelial-mesenchymal transition (EMT). Frizzled 7 (FZD7), a member of Frizzled family, promotes cell proliferation and invasiveness in many cancers, suggesting that FZD7 transmitting Wnt signaling is important for driving cancer growth. FZD7 expression has been reported to be up-regulated in human primary gastric cancer tissues. However, the molecular mechanism by which FZD7 promotes gastric cancer(GC) development and progression is not fully understood. Our present study showed that FZD7 was overexpressed in clinical GC samples, and thus was correlated with tumor invasion, lymphatic and organ metastasis, late TNM stages and poor patient survival. The endogenous expression of FZD7 was significantly increased in cancer stem cell-enriched spheres compared with adherent cells. Furthermore, RNA interference-mediated silencing of FZD7 inhibited proliferation, migration and invasion in gastric cancer cells. Moreover, ablation of FZD7 down-regulated EMT and the expression levels of cancer stem cell markers, and these inhibitions were associated with attenuated canonical Wnt/β-catenin signaling. The results suggest that Wnt canonical pathway may contribute to tumorigenesis and metastasis, indicating that FZD7 could be a potential therapeutic target for gastric cancer.

Zarei N, Fazeli M, Mohammadi M, Nejatollahi F
Cell growth inhibition and apoptosis in breast cancer cells induced by anti-FZD7 scFvs: involvement of bioinformatics-based design of novel epitopes.
Breast Cancer Res Treat. 2018; 169(3):427-436 [PubMed] Related Publications
BACKGROUND: FZD7 has a critical role as a surface receptor of Wnt/β-catenin signaling in cancer cells. Suppressing Wnt signaling through blocking FZD7 is shown to decrease cell viability, metastasis and invasion. Bioinformatic methods have been a powerful tool in epitope designing studies. Small size, high affinity and human origin of scFv antibodies have provided unique advantages for these recombinant antibodies.
METHODS: Two epitopes from extracellular domain of FZD7 were designed using bioinformatic methods. Specific anti-FZD7 scFvs were selected against these epitopes through panning process. The specificity of the scFvs was assessed by phage ELISA and the ability to bind to FZD7 expressing cell line (MDA-MB-231) was determined by flowcytometry. Antiproliferative and apoptotic effects of the scFvs were evaluated by MTT and Annexin V/PI assays. The effects of selected scFvs on expression level of Surivin, c-Myc and Dvl genes were also evaluated by real-time PCR.
RESULTS: Results demonstrated selection of two specific scFvs (scFv-I and scFv-II) with frequencies of 35 and 20%. Both antibodies bound to the corresponding peptides and cell surface receptors as shown by phage ELISA and flowcytometry, respectively. The scFvs inhibited cell growth of MDA-MB-231 cells significantly as compared to untreated cells. Growth inhibition of 58.6 and 53.1% were detected for scFv-I and scFv-II, respectively. No significant growth inhibition was detected for SKBR-3 negative control cells. The scFvs induced apoptotic effects in the MDA-MB-231 treated cells after 48 h, which were 81.6 and 74.9% for scFv-I and scFv-II, respectively. Downregulation of Surivin, c-Myc and Dvl genes were also shown after 48h treatment of cells with either of scFvs (59.3-93.8%). ScFv-I showed significant higher antiproliferative and apoptotic effects than scFv-II.
CONCLUSIONS: Bioinformatic methods could effectively select potential epitopes of FZD7 protein and suggest that epitope designing by bioinformatic methods could contribute to the selection of key antigens for cancer immunotherapy. The selected scFvs, especially scFv-I, with high antiproliferative and apoptotic effects could be considered as effective agents for immunotherapy of cancers expressing FZD7 receptor including triple negative breast cancer.

Xie SL, Fan S, Zhang SY, et al.
SOX8 regulates cancer stem-like properties and cisplatin-induced EMT in tongue squamous cell carcinoma by acting on the Wnt/β-catenin pathway.
Int J Cancer. 2018; 142(6):1252-1265 [PubMed] Related Publications
A sub-population of chemoresistant cells exhibits biological properties similar to cancer stem cells (CSCs), and these cells are believed to be a main cause for tumor relapse and metastasis. In our study, we explored the role of SOX8 and its molecular mechanism in the regulation of the stemness properties and the epithelial mesenchymal transition (EMT) of cisplatin-resistant tongue squamous cell carcinoma (TSCC) cells. We found that SOX8 was upregulated in cisplatin-resistant TSCC cells, which displayed CSC-like properties and exhibited EMT. SOX8 was also overexpressed in chemoresistant patients with TSCC and was associated with higher lymph node metastasis, advanced tumor stage and shorter overall survival. Stable knockdown of SOX8 in cisplatin-resistant TSCC cells inhibited chemoresistance, tumorsphere formation, and EMT. The Wnt/β-catenin pathway mediated the cancer stem-like properties in cisplatin-resistant TSCC cells. Further studies showed that the transfection of active β-catenin in SOX8 stable-knockdown cells partly rescued the SOX8 silencing-induced repression of stem-like features and chemoresistance. Through chromatin immunoprecipitation and luciferase assays, we observed that SOX8 bound to the promoter region of Frizzled-7 (FZD7) and induced the FZD7-mediated activation of the Wnt/β-catenin pathway. In summary, SOX8 confers chemoresistance and stemness properties and mediates EMT processes in chemoresistant TSCC via the FZD7-mediated Wnt/β-catenin pathway.

Song H, Nan Y, Wang X, et al.
MicroRNA‑613 inhibits proliferation and invasion of renal cell carcinoma cells through targeting FZD7.
Mol Med Rep. 2017; 16(4):4279-4286 [PubMed] Related Publications
MicroRNAs (miRNAs) have emerged as critical regulators in cancer progression. miR‑613 has been reported as a tumor suppressor gene in many types of human cancers. However, the function of miR‑613 in renal cell carcinoma (RCC) remains unclear. In the present study, the authors aimed to detect the expression of miR‑613 and its function in RCC cell lines. miR‑613 was reported to be significantly downregulated RCC cell lines. Functional analyses demonstrated that overexpression of miR‑613 significantly decreased RCC cell proliferation and invasion. Bioinformatics analysis showed that Frizzled7 (FZD7) was a predicted target of miR‑613, which was verified by dual‑luciferase reporter assay, reverse transcription quantitative‑polymerase chain reaction and western blot analysis. Restoration of FZD7 significantly reversed the suppressive effects of miR‑613 on RCC cell proliferation and invasion. Taken together, the results of the present study indicated that miR‑613 functions as a tumor suppressor that inhibits RCC cell proliferation and invasion by targeting and inhibiting FZD7, providing novel insight into RCC pathogenesis and a potential therapeutic target for RCC.

Cheng ZX, Song YX, Wang ZY, et al.
miR-144-3p serves as a tumor suppressor by targeting FZD7 and predicts the prognosis of human glioblastoma.
Eur Rev Med Pharmacol Sci. 2017; 21(18):4079-4086 [PubMed] Related Publications
OBJECTIVE: Previous research indicated that miR-144-3p was associated with the regulation of the carcinogenic processes, but the role of miR-144-3p in glioblastoma (GBM) remains unclear. In this study, we aimed to analyze the role of miR-144-3p in GBM.
PATIENTS AND METHODS: The expression of miR-144-3p was measured in GBM tissues and adjacent non-malignant tissues using qRT-PCR. The correlation of miR-144-3p with clinicopathological features and prognosis was also analyzed. Cell proliferation, invasion, and migration assay were applied to assess the function of miR-144-3p in vitro. Bioinformatics prediction and luciferase assays were employed to identify the predicted microRNA (miRNA) which regulates Frizzled-7 (FZD7). The levels of FZD7 and FZD7 mRNA were determined by Western blot and RT-PCR.
RESULTS: The results showed that the miR-144-3p expression was significantly downregulated in tumor tissues and GBM cell lines compared with that in normal brain tissues and the normal human astrocytes. The levels of miR-144-3p were negatively correlated with the status of WHO grade and recurrence. Furthermore, patients with low serum levels of miR-144-3p had a significantly shorter median overall survival rate. Multivariate Cox regression analysis confirmed that low level of miR-144-3p expression predicted poor prognosis independently. Further function assays showed that miR-144-3p inhibited proliferation invasion and migration of GBM cells. Finally, miR-144-3p was demonstrated to bind to the wild-type 3' untranslated region of FZD7 but not with its mutant.
CONCLUSIONS: The results of the present study indicate that miR-144-3p suppresses tumor metastasis by targeting FZD7. This work also provides strong evidence that miR-144-3p is an independent prognostic factor for patients with GBM.

Sun Y, Xu T, Cao YW, Ding XQ
Antitumor effect of miR-27b-3p on lung cancer cells via targeting Fzd7.
Eur Rev Med Pharmacol Sci. 2017; 21(18):4113-4123 [PubMed] Related Publications
OBJECTIVE:   Lung cancer is the most common malignancy with the highest mortality rate among cancers. microRNAs (miRNAs) have been confirmed to be closely related to the physiological disorder, especially the tumor process. This study aimed to investigate the effect of miR-27b-3p on lung tumor cells.
MATERIALS AND METHODS: The expressions of miR-27b-3p in lung tumors and adjacent non-tumors lung tissues were compared. We test the bonding effect of miR-27b-3p on the Fzd7 promoter, and miR-27b-3p effects on the Fzd7 expression in both NCI-H446 and A549 cells. Then, effects of miR-27b-3p and Fzd7 on these cells viability, survival and apoptosis were detected, respectively. In addition, the possible mechanism of miR-27b-3p affected these cells apoptosis was explored by analyzing the expression of apoptosis-related factors.
RESULTS: We found that miR-27b-3p was low expressed in lung tumors compared to adjacent non-tumorous lung tissues. miR-27b-3p directly targeted Fzd7 promoter and negatively regulated Fzd7 expression. Fzd7 promoted NCI-H446 and A549 cells viability and survival, inhibited cells apoptosis. However, miR-27b-3p effects on these cells were quite the opposite to Fzd7. The expressions of apoptosis-related factors were associated positively with miR-27b-3p and showed a negative correlation with Fzd7 expression.
CONCLUSIONS: The miR-27b-3p was lowly expressed in lung cancer tissues, and played the role of a tumor suppressor. It could promote cell apoptosis and suppress cancer cells viability and survival via down-regulating Fzd7. It suggested that miR-27b-3p might be a potential target for the prophylaxis and treatment of lung cancer.

de Cássia Viu Carrara R, Fontes AM, Abraham KJ, et al.
Expression differences of genes in the PI3K/AKT, WNT/b-catenin, SHH, NOTCH and MAPK signaling pathways in CD34+ hematopoietic cells obtained from chronic phase patients with chronic myeloid leukemia and from healthy controls.
Clin Transl Oncol. 2018; 20(4):542-549 [PubMed] Related Publications
PURPOSE: The fusion gene BCR-ABL has an important role to the progression of chronic myeloid leukemia (CML) and several signaling pathways have been characterized as responsible for the terminal blastic phase (BP). However, the initial phase, the chronic phase (CP), is long lasting and there is much yet to be understood about the critical role of BCR-ABL in this phase. This study aims to evaluate transcriptional deregulation in CD34+ hematopoietic cells (CD34+ cells) from patients with untreated newly diagnosed CML compared with CD34+HC from healthy controls.
METHODS: Gene expression profiling in CML-CD34 cells and CD34 cells from healthy controls were used for this purpose with emphasis on five main pathways important for enhanced proliferation/survival, enhanced self-renewal and block of myeloid differentiation.
RESULTS: We found 835 genes with changed expression levels (fold change ≥ ±2) in CML-CD34 cells compared with CD34 cells. These include genes belonging to PI3K/AKT, WNT/b-catenin, SHH, NOTCH and MAPK signaling pathways. Four of these pathways converge to MYC activation. We also identified five transcripts upregulated in CD34-CML patients named OSBPL9, MEK2, p90RSK, TCF4 and FZD7 that can be potential biomarkers in CD34-CML-CP.
CONCLUSION: We show several mRNAs up- or downregulated in CD34-CML during the chronic phase.

Jiang C, Ding Z, Joy M, et al.
A balanced level of profilin-1 promotes stemness and tumor-initiating potential of breast cancer cells.
Cell Cycle. 2017; 16(24):2366-2373 [PubMed] Free Access to Full Article Related Publications
Profilin-1 (Pfn1) is an important actin-regulatory protein that is downregulated in human breast cancer and when forcibly elevated, it suppresses the tumor-initiating ability of triple-negative breast cancer cells. In this study, we demonstrate that Pfn1 overexpression reduces the stem-like phenotype (a key biologic feature associated with higher tumor-initiating potential) of MDA-MB-231 (MDA-231) triple-negative breast cancer cells. Interestingly, the stem-like trait of MDA-231 cells is also attenuated upon depletion of Pfn1. A comparison of cancer stem cell gene (CSC) gene expression signatures between depleted and elevated conditions of Pfn1 further suggest that Pfn1 may be somehow involved in regulating the expression of a few CSC-related genes including MUC1, STAT3, FZD7, and ITGB1. Consistent with the reduced stem-like phenotype associated with loss-of-function of Pfn1, xenograft studies showed lower tumor-initiating frequency of Pfn1-depleted MDA-231 cells compared to their control counterparts. In MMTV:PyMT mouse model, homozygous but not heterozygous deletion of Pfn1 gene leads to severe genetic mosaicism and positive selection of Pfn1-proficient tumor cells further supporting the contention that a complete lack of Pfn1 is likely not conducive for efficient tumor initiation capability of breast cancer cells. In summary, these findings suggest that the maintenance of optimal stemness and tumor-initiating ability of breast cancer cells requires a balanced expression of Pfn1.

Liu X, Yan Y, Ma W, Wu S
Knockdown of frizzled-7 inhibits cell growth and metastasis and promotes chemosensitivity of esophageal squamous cell carcinoma cells by inhibiting Wnt signaling.
Biochem Biophys Res Commun. 2017; 490(3):1112-1118 [PubMed] Related Publications
A growing body of evidence suggests that frizzled-7 (FZD7) is an important oncogene in multiple human malignancies and is involved in regulating sensitivity to chemotherapeutic drugs. However, little is known about the expression and function of FZD7 in esophageal squamous cell carcinoma (ESCC). In this study, we aimed to investigate the functional significance of FZD7 in ESCC. Here, we found that both mRNA and protein expression levels of FZD7 were highly upregulated in ESCC cell lines. The knockdown of FZD7 inhibited cell growth, induced cell apoptosis, and suppressed cell migration and invasion of ESCC cells in vitro. Furthermore, knockdown of FZD7 promoted chemosensitivity to cisplatin in ESCC cells and suppressed the expression of multidrug resistance protein 1. Moreover, the silencing of FZD7 also significantly impeded the activation of Wnt signaling in ESCC cells. Taken together, our study reveals an oncogenic role of FZD7 in the progression of ESCC and suggests that FZD7 might serve as a potential therapeutic target for treatment of ESCC.

Schwab RHM, Amin N, Flanagan DJ, et al.
Wnt is necessary for mesenchymal to epithelial transition in colorectal cancer cells.
Dev Dyn. 2018; 247(3):521-530 [PubMed] Related Publications
BACKGROUND: Metastasis underlies most colorectal cancer mortality. Cancer cells spread through the body as single cells or small clusters of cells that have an invasive, mesenchymal, nonproliferative phenotype. At the secondary site, they revert to a proliferative "tumor constructing" epithelial phenotype to rebuild a tumor. We previously developed a unique in vitro three-dimensional model, called LIM1863-Mph, which faithfully recapitulates these reversible transitions that underpin colorectal cancer metastasis. Wnt signaling plays a key role in these transitions and is initiated by the coupling of extracellular Wnt to Frizzled (FZD). Using the LIM1863-Mph model system we demonstrated that the Wnt receptor FZD7 is necessary for mesenchymal to epithelial transition (MET). Here we investigate the role of Wnt in MET.
RESULTS: Wnt secretion is dependent on palmitoylation by Porcupine (PORC). A PORC inhibitor (IWP2) that prevents Wnt secretion, blocked the epithelial transition of mesenchymal LIM1863-Mph cells. Wnt gene array analysis identified several Wnts that are upregulated in epithelial compared with mesenchymal LIM1863-Mph cells, suggesting these ligands in MET. Wnt2B was the most abundant differentially expressed Wnt gene. Indeed, recombinant Wnt2B could overcome the IWP2-mediated block in epithelial transition of mesenchymal LIM1863-Mph cells.
CONCLUSIONS: Wnt2B co-operates with Frizzled7 to mediate MET in colorectal cancer. Developmental Dynamics 247:521-530, 2018. © 2017 Wiley Periodicals, Inc.

Wu J, Li J, Ren J, Zhang D
MicroRNA-485-5p represses melanoma cell invasion and proliferation by suppressing Frizzled7.
Biomed Pharmacother. 2017; 90:303-310 [PubMed] Related Publications
MicroRNAs (miRNAs) have emerged as critical regulators for malignant melanoma development. miR-485-5p has been suggested as a tumor-suppressive miRNA in many types of human malignancies. However, the role of miR-485-5p in melanoma remains unknown. In this study, we aimed to explore the potential role and underlying mechanism of miR-485-5p in the regulation of melanoma development. Here, we showed that miR-485-5p was significantly decreased in melanoma tissues and cell lines compared with their corresponding controls. Transwell invasion assay showed that miR-485-5p overexpression markedly inhibited melanoma cell invasion. WST-1 and cell cycle assays exhibited that miR-485-5p overexpression significantly suppressed melanoma cell proliferation. By contrast, miR-485-5p suppression promoted the invasion and proliferation of melanoma cells. Using bioinformatics analysis, we observed that miR-485-5p potentially targets the 3'-untranslated region (3'-UTR) of Frizzled7 (FZD7). Dual-luciferase assay confirmed the direct binding between miR-485-5p and FZD7 3'-UTR. Meanwhile, real-time quantitative polymerase chain reaction and Western blot analysis showed that miR-485-5p overexpression suppressed FZD7 expression, whereas miR-485-5p suppression resulted in the opposite effect. Moreover, miR-485-5p expression was observed to be inversely correlated with FZD7 mRNA expression in melanoma tissues. Further experiments showed that miR-485-5p regulated Wnt signaling. The restoration of FZD7 expression markedly reversed the antitumor effects induced by miR-485-5p overexpression in melanoma cells. Taken together, our study suggests that miR-485-5p represses melanoma cell invasion and proliferation by suppressing FZD7, indicating a new tumor-suppressive role for miR-485-5p in melanoma. The miR-485-5p/FZD7 axis may provide novel insights into understanding the molecular pathogenesis of melanoma and may be a promising therapeutic target for melanoma.

Duffy DJ, Krstic A, Halasz M, et al.
Retinoic acid and TGF-β signalling cooperate to overcome MYCN-induced retinoid resistance.
Genome Med. 2017; 9(1):15 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Retinoid therapy is widely employed in clinical oncology to differentiate malignant cells into their more benign counterparts. However, certain high-risk cohorts, such as patients with MYCN-amplified neuroblastoma, are innately resistant to retinoid therapy. Therefore, we employed a precision medicine approach to globally profile the retinoid signalling response and to determine how an excess of cellular MYCN antagonises these signalling events to prevent differentiation and confer resistance.
METHODS: We applied RNA sequencing (RNA-seq) and interaction proteomics coupled with network-based systems level analysis to identify targetable vulnerabilities of MYCN-mediated retinoid resistance. We altered MYCN expression levels in a MYCN-inducible neuroblastoma cell line to facilitate or block retinoic acid (RA)-mediated neuronal differentiation. The relevance of differentially expressed genes and transcriptional regulators for neuroblastoma outcome were then confirmed using existing patient microarray datasets.
RESULTS: We determined the signalling networks through which RA mediates neuroblastoma differentiation and the inhibitory perturbations to these networks upon MYCN overexpression. We revealed opposing regulation of RA and MYCN on a number of differentiation-relevant genes, including LMO4, CYP26A1, ASCL1, RET, FZD7 and DKK1. Furthermore, we revealed a broad network of transcriptional regulators involved in regulating retinoid responsiveness, such as Neurotrophin, PI3K, Wnt and MAPK, and epigenetic signalling. Of these regulators, we functionally confirmed that MYCN-driven inhibition of transforming growth factor beta (TGF-β) signalling is a vulnerable node of the MYCN network and that multiple levels of cross-talk exist between MYCN and TGF-β. Co-targeting of the retinoic acid and TGF-β pathways, through RA and kartogenin (KGN; a TGF-β signalling activating small molecule) combination treatment, induced the loss of viability of MYCN-amplified retinoid-resistant neuroblastoma cells.
CONCLUSIONS: Our approach provides a powerful precision oncology tool for identifying the driving signalling networks for malignancies not primarily driven by somatic mutations, such as paediatric cancers. By applying global omics approaches to the signalling networks regulating neuroblastoma differentiation and stemness, we have determined the pathways involved in the MYCN-mediated retinoid resistance, with TGF-β signalling being a key regulator. These findings revealed a number of combination treatments likely to improve clinical response to retinoid therapy, including co-treatment with retinoids and KGN, which may prove valuable in the treatment of high-risk MYCN-amplified neuroblastoma.

Qiu X, Jiao J, Li Y, Tian T
Overexpression of FZD7 promotes glioma cell proliferation by upregulating TAZ.
Oncotarget. 2016; 7(52):85987-85999 [PubMed] Free Access to Full Article Related Publications
Gliomas are the most prevalent type of primary brain tumors in adults, accounting for more than 40% of neoplasm in the central nervous system. Frizzled-7 (FZD7) is a seven-pass trans-membrane Wnt receptor that plays a critical role in the development of various tumors. In this study, we detected high-level FZD7 expression in glioma and its overexpression was associated with advanced tumor stage. In vitro functional assays showed that forced overexpression of FZD7 promoted proliferation of gliomas cells, whereas knockdown of endogenous FZD7 significantly suppressed proliferation ability of these cells. In a xenograft assay, FZD7 was also found to promote the growth of glioma cells. We further found that FZD7 could activate transcriptional coactivator with PDZ-binding motif (TAZ), and TAZ was required for FZD7 to promote cell proliferation in glioma. Furthermore, the univariate analysis of survival shows that glioma patients with high FZD7 expression have a shorter survival. In conclusion, our findings demonstrate that FZD7 may promote glioma cell proliferation via upregulation of TAZ.

Nickho H, Younesi V, Aghebati-Maleki L, et al.
Developing and characterization of single chain variable fragment (scFv) antibody against frizzled 7 (Fzd7) receptor.
Bioengineered. 2017; 8(5):501-510 [PubMed] Free Access to Full Article Related Publications
ABSTACT Wnt/β-catenin signaling pathway through Frizzled receptors has been shown to play a key role in both normal development and tumorigenesis. Overexpression of Wnt pathway genes, such as Fzd7 in several malignancies is well-documented. Therefore, targeting of Fzd7 and its ligand inhibits cancer cells proliferation metastasis. In the present study we isolated single chain variable fragments (scFvs) against Fzd7 receptor using phage display method. Semi-synthetic human naive antibody libraries (Tomlinson I + J) was employed in panning procedure to isolate specific scFv against specific peptide from extracellular domain of Fzd7 receptor. The reactivity and growth inhibition effects of the selected antibodies was evaluated using enzyme-linked immunosorbent assay (ELISA), MTT and annexin V assays, respectively. Seven scFvs reactive to Fzd7 were selected following 4 rounds of panning. The results showed that the selected scFvs inhibits cell growth through apoptosis cell death in a triple negative breast cancer cells, MDA-MB-231. Given that Fzd7 and Wnt pathway plays a critical role in tumor progression, selected blocking scFvs represent significant potential for immunotherapy of breast cancer cells.

Wu W, Dang S, Feng Q, et al.
MicroRNA-542-3p inhibits the growth of hepatocellular carcinoma cells by targeting FZD7/Wnt signaling pathway.
Biochem Biophys Res Commun. 2017; 482(1):100-105 [PubMed] Related Publications
MicroRNAs (miRNA) are relevant regulators of the tumorigenesis of various cancers, such as hepatocellular carcinoma (HCC). Recent studies have suggested that miR-542-3p is a tumor suppressor gene in numerous cancers. However, the role of miR-542-3p in HCC remains unclear. This study showed that miR-542-3p was downregulated in HCC tissues and cell lines. MTT, colony formation, and cell cycle assays revealed that miR-542-3p overexpression inhibited HCC cell growth, whereas miR-542-3p suppression promoted cell growth. Frizzled7 (FZD7), the most important Wnt receptor involved in cancer development and progression, was identified as a functional target of miR-542-3p through dual-luciferase reporter assay, RT-qPCR, and Western blot. The mRNA expression of FZD7 was inversely correlated with miR-542-3p expression in HCC tissues. miR-542-3p overexpression could significantly decrease the activation of Wnt signaling pathway in HCC cells. FZD7 overexpression could significantly reverse the inhibitory effect of miR-542-3p on HCC cell growth and Wnt signaling pathway. Taken together, our study suggests that miR-542-3p inhibits HCC cell growth by targeting FZD7 and inhibiting Wnt signaling pathway. The decreased miR-542-3p expression may also contribute to the progression of HCC and may represent a novel molecular therapeutic target for HCC.

Mebarki S, Désert R, Sulpice L, et al.
De novo HAPLN1 expression hallmarks Wnt-induced stem cell and fibrogenic networks leading to aggressive human hepatocellular carcinomas.
Oncotarget. 2016; 7(26):39026-39043 [PubMed] Free Access to Full Article Related Publications
About 20% hepatocellular carcinomas (HCCs) display wild-type β-catenin, enhanced Wnt signaling, hepatocyte dedifferentiation and bad outcome, suggesting a specific impact of Wnt signals on HCC stem/progenitor cells. To study Wnt-specific molecular pathways, cell fates and clinical outcome, we fine-tuned Wnt/β-catenin signaling in liver progenitor cells, using the prototypical Wnt ligand Wnt3a. Cell biology assays and transcriptomic profiling were performed in HepaRG hepatic progenitors exposed to Wnt3a after β-catenin knockdown or Wnt inhibition with FZD8_CRD. Gene expression network, molecular pathology and survival analyses were performed on HCCs and matching non-tumor livers from 70 patients by real-time PCR and tissue micro-array-based immunohistochemistry. Wnt3a reprogrammed liver progenitors to replicating fibrogenic myofibroblast-like cells displaying stem and invasive features. Invasion was inhibited by 30 nM FZD7 and FZD8 CRDs. Translation of these data to human HCCs revealed two tight gene networks associating cell surface Wnt signaling, stem/progenitor markers and mesenchymal commitment. Both networks were linked by Hyaluronan And Proteoglycan Link Protein 1 (HAPLN1), that appeared de novo in aggressive HCCs expressing cytoplasmic β-catenin and stem cell markers. HAPLN1 was independently associated with bad overall and disease-free outcome. In vitro, HAPLN1 was expressed de novo in EPCAM¯/NCAM+ mesoderm-committed progenitors, upon spontaneous epithelial-mesenchymal transition and de-differentiation of hepatocyte-like cells to liver progenitors. In these cells, HAPLN1 knockdown downregulated key markers of mesenchymal cells, such as Snail, LGR5, collagen IV and α-SMA. In conclusion, HAPLN1 reflects a signaling network leading to stemness, mesenchymal commitment and HCC progression.

Désert R, Mebarki S, Desille M, et al.
"Fibrous nests" in human hepatocellular carcinoma express a Wnt-induced gene signature associated with poor clinical outcome.
Int J Biochem Cell Biol. 2016; 81(Pt A):195-207 [PubMed] Related Publications
Hepatocellular carcinoma (HCC) is the 3rd cause of cancer-related death worldwide. Most cases arise in a background of chronic inflammation, extracellular matrix (ECM) remodeling, severe fibrosis and stem/progenitor cell amplification. Although HCCs are soft cellular tumors, they may contain fibrous nests within the tumor mass. Thus, the aim of this study was to explore cancer cell phenotypes in fibrous nests. Combined anatomic pathology, tissue microarray and real-time PCR analyses revealed that HCCs (n=82) containing fibrous nests were poorly differentiated, expressed Wnt pathway components and target genes, as well as markers of stem/progenitor cells, such as CD44, LGR5 and SOX9. Consistently, in severe liver fibroses (n=66) and in HCCs containing fibrous nests, weighted correlation analysis revealed a gene network including the myofibroblast marker ACTA2, the basement membrane components COL4A1 and LAMC1, the Wnt pathway members FZD1; FZD7; WNT2; LEF1; DKK1 and the Secreted Frizzled Related Proteins (SFRPs) 1; 2 and 5. Moreover, unbiased random survival forest analysis of a transcriptomic dataset of 247 HCC patients revealed high DKK1, COL4A1, SFRP1 and LAMC1 to be associated with advanced tumor staging as well as with bad overall and disease-free survival. In vitro, these genes were upregulated in liver cancer stem/progenitor cells upon Wnt-induced mesenchymal commitment and myofibroblast differentiation. In conclusion, fibrous nests express Wnt target genes, as well as markers of cancer stem cells and mesenchymal commitment. Fibrous nests embody the specific microenvironment of the cancer stem cell niche and can be detected by routine anatomic pathology analyses.

Schiffgens S, Wilkens L, Brandes AA, et al.
Sex-specific clinicopathological significance of novel (Frizzled-7) and established (MGMT, IDH1) biomarkers in glioblastoma.
Oncotarget. 2016; 7(34):55169-55180 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: The Wnt receptor Frizzled-7 (FZD7) promotes tumor progression and can be currently targeted by monoclonal antibody therapy. Here, we determined the prognostic value of FZD7 for the overall survival of glioblastoma (GBM) patients, both as individual marker and taken in combination with the previously-described markers MGMT and IDH1. Additionally, we tested whether these markers (alone or in combination) exhibited sex-specific differences.
RESULTS: High levels of FZD7 (FZD7high) associated with shorter survival in GBM patients; however, FZD7high was a significant predictor of poor survival only in male patients. Mutation of IDH1 significantly associated with longer survival in male but not female patients. Methylated MGMT promoter significantly associated with longer survival only in female patients. Combination of FZD7 with MGMT enhanced the prognostic accuracy and abrogated the sex differences observed upon single marker analysis. Combination of FZD7 with IDH1 was a significant predictor of survival in male GBM patients only.
MATERIALS AND METHODS: Three independent cohorts of patients with primary GBM (n=120, n=108 and n=105, respectively) were included in this study. FZD7 and IDH1 were assessed by immunohistochemistry in tissue microarrays. MGMT promoter methylation was determined by methylation-specific polymerase chain reaction. Survival analysis was performed by Kaplan-Meier estimate, log-rank test and Cox proportional hazard regression.
CONCLUSIONS: Our study identifies novel individual and combination markers with prognostic and, possibly, therapeutic relevance in GBM. Furthermore, our findings substantiate the importance of sexual dimorphism in this type of cancer.

Leung CO, Mak WN, Kai AK, et al.
Sox9 confers stemness properties in hepatocellular carcinoma through Frizzled-7 mediated Wnt/β-catenin signaling.
Oncotarget. 2016; 7(20):29371-86 [PubMed] Free Access to Full Article Related Publications
Sox9, an SRY-related HMG box transcription factor, is a progenitor/precursor cell marker of the liver expressed during embryogenesis and following liver injury. In this study, we investigated the role of Sox9 and its molecular mechanism with reference to stemness properties in hepatocellular carcinoma (HCC). Here, we observed upregulation of Sox9 in human HCC tissues compared with the non-tumorous liver counterparts (p < 0.001). Upregulation of Sox9 transcript level was associated with poorer tumor cell differentiation (p = 0.003), venous invasion (p = 0.026), advanced tumor stage (p = 0.044) and shorter overall survival (p = 0.042). Transcript levels of Sox9 and CD24 were positively correlated. Silencing of Sox9 in HCC cells inhibited in vitro cell proliferation and tumorsphere formation, sensitized HCC cells to chemotherapeutic agents, and suppressed in vivo tumorigenicity. In addition, knockdown of Sox9 suppressed HCC cell migration, invasion, and in vivo lung metastasis. Further studies showed that Sox9 endowed stemness features through activation of Wnt/β-catenin signaling, which was confirmed by the partial rescue effect on tumorigenicity and self-renewal upon transfection of active β-catenin in Sox9 knockdown cells. By ChIP and luciferase promoter assays, Frizzled-7 was identified to be the direct transcriptional target of Sox9. In conclusion, Sox9 confers stemness properties of HCC through Frizzled-7 mediated Wnt/β-catenin pathway.

Tiwary S, Xu L
FRIZZLED7 Is Required for Tumor Initiation and Metastatic Growth of Melanoma Cells.
PLoS One. 2016; 11(1):e0147638 [PubMed] Free Access to Full Article Related Publications
Metastases are thought to arise from cancer stem cells and their tumor initiating abilities are required for the establishment of metastases. Nevertheless, in metastatic melanoma, the nature of cancer stem cells is under debate and their contribution to metastasis formation remains unknown. Using an experimental metastasis model, we discovered that high levels of the WNT receptor, FZD7, correlated with enhanced metastatic potentials of melanoma cell lines. Knocking down of FZD7 in a panel of four melanoma cell lines led to a significant reduction in lung metastases in animal models, arguing that FZD7 plays a causal role during metastasis formation. Notably, limiting dilution analyses revealed that FZD7 is essential for the tumor initiation of melanoma cells and FZD7 knockdown impeded the early expansion of metastatic melanoma cells shortly after seeding, in accordance with the view that tumor initiating ability of cancer cells is required for metastasis formation. FZD7 activated JNK in melanoma cell lines in vitro and the expression of a dominant negative JNK suppressed metastasis formation in vivo, suggesting that FZD7 may promote metastatic growth of melanoma cells via activation of JNK. Taken together, our findings uncovered a signaling pathway that regulates the tumor initiation of melanoma cells and contributes to metastasis formation in melanoma.

Geng Y, Lu X, Wu X, et al.
MicroRNA-27b suppresses Helicobacter pylori-induced gastric tumorigenesis through negatively regulating Frizzled7.
Oncol Rep. 2016; 35(4):2441-50 [PubMed] Related Publications
MicroRNAs (miRNAs) are novel tools for cancer therapy. Frizzled7 (FZD7) is an important co-receptor in the WNT signaling pathway. The WNT signaling pathway is aberrantly activated in Helicobacter pylori (H. pylori)‑infected gastric cancer cells. However, the role of FZD7 in H. pylori‑induced gastric tumorigenesis remains unknown. In this study, we investigated the potential role of FZD7 in H. pylori-induced gastric tumorigenesis and validated the possibility that targeting of FZD7 by specific miRNA inhibits H. pylori-induced gastric tumorigenesis. First, we found that FZD7 was significantly induced by H. pylori infection in a dose- and time-dependent manner. Knockdown of FZD7 by FZD7 small interfering RNA effectively inhibited H. pylori infection-induced cell proliferation of gastric cancer cells. We found that microRNA-27b (miR-27b) was the predicted miRNA for FZD7 and that miR-27b negatively regulated FZD7 expression by targeting the 3'-untranslated region of FZD7. Furthermore, miR-27b overexpression significantly inhibited H. pylori infection-induced cell proliferation and WNT signaling pathway activation in gastric cancer cells. Restoration of FZD7 expression significantly attenuated the inhibitory effect of miR-27b overexpression on cell proliferation and WNT signaling pathway activation. Collectively, our study suggests that FZD7 triggered by H. pylori infection contributes to the H. pylori infection-induced cell proliferation that links the WNT. Thus, miR-27b may be a promising molecular target for the treatment of the disease.

Kierulf-Vieira KS, Sandberg CJ, Grieg Z, et al.
Wnt inhibition is dysregulated in gliomas and its re-establishment inhibits proliferation and tumor sphere formation.
Exp Cell Res. 2016; 340(1):53-61 [PubMed] Related Publications
Evidence indicates that the growth of glioblastoma (GBM), the most common and malignant primary brain cancer, is driven by glioma stem cells (GSCs) resistant to current treatment. As Wnt-signaling is pivotal in stem cell maintenance, we wanted to explore its role in GSCs with the objective of finding distinct signaling mechanisms that could serve as potential therapeutic targets. We compared gene expression in GSCs (n=9) and neural stem cells from the adult human brain (ahNSC; n=3) to identify dysregulated genes in the Wnt signaling pathway. This identified a six-gene Wnt signature present in all nine primary GSC cultures, and the combined expression of three of these genes (SFRP1, SFRP4 and FZD7) reduced median survival of glioma patients from 38 to 17 months. Treatment with recombinant SFRP1 protein in primary cell cultures downregulated nuclear β-catenin and decreased in vitro proliferation and sphere formation in a dose-dependent manner. Furthermore, expressional and functional analysis of SFRP1-treated GSCs revealed that SFRP1 halts cell cycling and induces apoptosis. These observations demonstrate that Wnt signaling is dysregulated in GSC, and that inhibition of the Wnt pathway could serve as a therapeutic strategy in the treatment of GBM.

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