Increased LEF1 expression and decreased Notch2 expression are strong predictors of poor outcomes in colorectal cancer patients

Integrative analysis of exosomal ncRNAs and their regulatory networks in liver cancer progression

Background

Hepatocellular carcinoma (HCC) is a significant global health challenge with complex molecular underpinnings. Recent advancements in understanding the role of non-coding RNAs (ncRNAs) and exosomes in cancer biology have opened new avenues for research into potential diagnostic and therapeutic strategies.

Methods

This study utilized a comprehensive approach to analyze gene expression patterns and regulatory networks in HCC. We integrated RNA sequencing data gathered from both tissue samples and exosomes. The WGCNA and limma R packages were employed to construct co-expression networks and identify differentially expressed ncRNAs, including long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs).

Results

Our analysis demonstrated distinct expression profiles of various ncRNAs in HCC, revealing their intricate interactions with cancer-related genes. Key findings include the identification of a network of microRNAs that interact with selected lncRNAs and their potential roles as biomarkers. Moreover, exosomal RNA was shown to effectively reflect tissue-specific gene expression changes.

Conclusions

The results of this study highlight the significance of exosomal ncRNAs in the progression of liver cancer, suggesting their potential as both diagnostic biomarkers and therapeutic targets. Future research should focus on the functional implications of these ncRNAs to further elucidate their roles in HCC and explore their applications in clinical settings.

Machine learning and experimental analyses identified miRNA expression models associated with metastatic osteosarcoma

Osteosarcoma (OS), as the most common primary bone cancer, has a high invasiveness and metastatic potential, therefore, it has a poor prognosis. This study identified early diagnostic biomarkers using miRNA expression profiles associated with osteosarcoma metastasis. In the first step, we used RNA-seq and online microarray data from osteosarcoma tissues and cell lines to identify differentially expressed miRNAs. Then, using seven feature selection algorithms for ranking, the first-ranked miRNAs were selected as input for five machine learning systems. Using network analysis and machine learning algorithms, we developed new diagnostic models that successfully differentiated metastatic osteosarcoma from non-metastatic samples based on newly discovered miRNA signatures. The results showed that miR-34c-3p and miR-154-3p act as the most promising models in the diagnosis of metastatic osteosarcoma. Validation for this model by RT-qPCR in benign tissue and osteosarcoma biopsies confirmed the lower expression of miR-34c-3p and miR-154-3p in OS samples. In addition, a direct correlation between miR-34c-3p expression, miR-154-3p expression and tumor grade was discovered. The combined values of miR-34c-3p and miR-154-3p showed 90 % diagnostic power (AUC = 0.90) for osteosarcoma samples and 85 % (AUC = 0.85) for metastatic osteosarcoma. Adhesion junction and focal adhesion pathways, as well as epithelial-to-mesenchymal transition (EMT) GO terms, were identified as the most significant KEGG and GO terms for the top miRNAs. The findings of this study highlight the potential use of novel miRNA expression signatures for early detection of metastatic osteosarcoma. These findings may help in determining therapeutic approaches with a quantitative and faster method of metastasis detection and also be used in the development of targeted molecular therapy for this aggressive cancer. Further research is needed to confirm the clinical utility of miR-34c-3p and miR-154-3p as diagnostic biomarkers for metastatic osteosarcoma.

Advances in invasive micropapillary carcinoma of the breast research: A review

Invasive micropapillary carcinoma (IMPC) of the breast represents a rare subtype of breast cancer, accounting for 1% to 2% of all breast cancers worldwide. Although clinically asymptomatic, they are usually detected during routine breast screenings. The common symptoms include breast lumps, skin or nipple changes, and nipple discharge. Histopathologically, IMPCs are characterized by tumor cells forming small papillary-like structures inside the glandular spaces, and arranged in an inverted pattern, with their apex pointing toward the center of the gland. This unique morphological feature is critical for diagnosing these cases. Another notable characteristic is its high propensity for lymph node metastasis (LNM). While the precise mechanism of metastasis is not clear, unique cellular arrangement and cellular interactions with the surrounding environment might promote tumorigenesis and higher node positivity. Hence, proper lymph node dissection and assessment are particularly crucial for this type of breast cancer. This review aims to discuss the recent progress in managing IMPC cases.

Effects of S-Adenosylhomocysteine Hydrolase Downregulation on Wnt Signaling Pathway in SW480 Cells

S-adenosylhomocysteine hydrolase (AHCY) deficiency results mainly in hypermethioninemia, developmental delay, and is potentially fatal. In order to shed new light on molecular aspects of AHCY deficiency, in particular any changes at transcriptome level, we enabled knockdown of AHCY expression in the colon cancer cell line SW480 to simulate the environment occurring in AHCY deficient individuals. The SW480 cell line is well known for elevated AHCY expression, and thereby represents a suitable model system, in particular as AHCY expression is regulated by MYC, which, on the other hand, is involved in Wnt signaling and the regulation of Wnt-related genes, such as the β-catenin co-transcription factor LEF1 (lymphoid enhancer-binding factor 1). We selected LEF1 as a potential target to investigate its association with S-adenosylhomocysteine hydrolase deficiency. This decision was prompted by our analysis of RNA-Seq data, which revealed significant changes in the expression of genes related to the Wnt signaling pathway and genes involved in processes responsible for epithelial-mesenchymal transition (EMT) and cell proliferation. Notably, LEF1 emerged as a common factor in these processes, showing increased expression both on mRNA and protein levels. Additionally, we show alterations in interconnected signaling pathways linked to LEF1, causing gene expression changes with broad effects on cell cycle regulation, tumor microenvironment, and implications to cell invasion and metastasis. In summary, we provide a new link between AHCY deficiency and LEF1 serving as a mediator of changes to the Wnt signaling pathway, thereby indicating potential connections of AHCY expression and cancer cell phenotype, as Wnt signaling is frequently associated with cancer development, including colorectal cancer (CRC).

β-Sitosterol blocks the LEF-1-mediated Wnt/β-catenin pathway to inhibit proliferation of human colon cancer cells

OBJECTIVES

This study aimed to investigate the LEF-1-mediated Wnt/β-catenin pathway for its biological functions and prognostic value in colon cancer (CC). Furthermore, the potential molecular mechanism of β-sitosterol in CC was investigated in vitro.

METHODS

Clinical information and gene expression profiles from CC patients were obtained based on Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. In addition, we applied R software "Limma" package for the differential analysis of LEF-1 between cancer and para-carcinoma tissue samples. Kaplan-Meier (KM) survival analysis was adopted for analyzing whether LEF-1 was of prognostic significance. Moreover, gene set enrichment analysis (GSEA) was adopted for pathway enrichment analysis and visualization. In addition, CCK8, plate cloning, scratch and high-content screening (HCS) imaging assays were performed to examine the therapeutic efficacy of β-sitosterol in human CC HCT116 cells. siRNA technology was employed to knock down LEF1 expression in HCT116 cells. qRT-PCR and Western-blot (WB) analysis were carried out to analyze the HCT-116 mRNA and protein expression levels, respectively.

RESULTS

LEF-1 was up-regulated within CC and acted as an oncogenic gene. LEF-1 up-regulation predicted the dismal prognostic outcome and activated the Wnt/β-catenin pathway. β-sitosterol effectively suppressed HCT116 cells proliferation and invasion. For the mechanism underlying β-sitosterol, β-sitosterol was found to significantly down-regulate LEF-1 gene and protein expression and disrupt Wnt/β-catenin pathway transmission in HCT116 cells. After suppressing LEF-1 expression, its downstream targets including C-myc, Survivin and CCND1 were also down-regulated.

CONCLUSION

According to our results, LEF-1 down-regulation can effectively block Wnt/β-catenin pathway, inhibit CC cell growth and migration. Collectively, β-sitosterol can be used to treat CC, which can provide anti-tumor activity by targeting LEF-1.

The expression changes of transcription factors including ANKZF1, LEF1, CASZ1, and ATOH1 as a predictor of survival rate in colorectal cancer: a large-scale analysis

INTRODUCTION

Transcription factors (TFs) are essential for many biological processes and regulate the expression of several genes. This study's objective was to analyze the abnormalities in TF expression, their impact on patient prognosis, and related pathways in colorectal cancer (CRC).

METHOD

The expression alterations of all TFs were investigated using the cancer genome atlas and GSE39582 data. Clinical data were also used to study the association between TFs expression and patient prognosis through the Cox regression test, and a predictive model of CRC patient survival was constructed based on TFs expression. Co-expression network was used to discover TF-related pathways. To validate the findings, the RT-qPCR method was applied to CRC samples and adjacent normal tissue.

RESULTS

The findings revealed that ANKZF1, SALL4, SNAI1, TIGD1, LEF1, FOXS1, SIX4, and ETV5 expression levels increased in both cohorts and were linked to the poor prognosis. NR3C2, KLF4, CASZ1, FOXD2, ATOH1, SALL1, and RORC expression, on the other hand, exhibited a significant decrease, and their increase was related to the good prognosis of patients. The patient mortality risk model based on expression of mentioned TFs revealed that, independent of clinical characteristics, the expression of ANKZF1, LEF1, CASZ1, and ATOH1 could accurately predict patient survival rates. According to the co-expression network, increased transcription factors were linked to metastatic pathways, while decreasing TFs were involved to apoptotic pathways. RT-qPCR findings showed that FOXS1 expression was markedly overexpressed in CRC samples. However, in CRC samples, the expression of CASZ1 decreased.

CONCLUSION

In CRC, TFs expression of ANKZF1, LEF1, CASZ1 and ATOH1 are deregulated, which are associated with prognosis in patients. According to our findings, changes in the expression of the mentioned TFs have the potential to be considered diagnostic and prognostic biomarkers for CRC patients.

MicroRNA-621 functions as a metastasis suppressor in colorectal cancer by directly targeting LEF1 and suppressing Wnt/β-catenin signaling

AIMS

Colorectal liver metastasis (CRLM) is the leading death-causing among colorectal cancer (CRC) patients. Recently, a novel tumor-related microRNA, miR-621, has been identified as a tumor suppressor in diverse tumor types, but its role in CRLM remains unclear and requires further investigation.

MAIN METHODS

To elucidate novel regulators of CRLM progression, we used a well-established CRLM animal model. After serially transplanting human colon carcinoma cell lines Caco-2 into the liver, we obtained liver metastatic variants that exhibited a strong ability for invasion and metastasis. High-throughput sequencing was conducted on these newly established cell lines. After comparison and prediction between the two cell lines: parental Caco-2 (hereafter referred to as F0) and F3, miR-621 was identified as a candidate regulator for lymphoid enhancer-binding factor 1 (LEF1) expression. Further validation was achieved with dual-luciferase reporter assay.

KEY FINDINGS

The gain- and loss-of-function validation showed that miR-621 inhibits cell viability, cell cycle progression, colony formation, and proliferation in vitro. Meanwhile, miR-621 could reverse EMT malignant phenotype. LEF1, an important downstream mediator of activated Wnt/β-catenin signaling pathway, was validated as the direct functional target of miR-621. miR-621 interacts directly with the LEF1 3'-UTR and post-transcriptionally suppresses LEF1 expression. Moreover, LEF1 overexpression reversed the effect of miR-621. LEF1 silencing counteracted miR-621 down-regulation-induced effects. Further in vivo experiments revealed that miR-621 over-expression suppressed CRLM, but LEF1 abrogated the inhibitory effect of miR-621.

SIGNIFICANCE

MiR-621 is a vital tumor suppressor in CRC and could be a promising anti-cancer therapeutic target.

Increased Expression of LEF1 and β-Catenin in Invasive Micropapillary Carcinoma of the Breast is Associated With Lymphovascular Invasion and Lymph Node Metastasis

Invasive micropapillary breast carcinoma (IMPC) is a rare breast cancer subtype characterized by small tumor cell clusters with loss of stromal attachment, an inside-out growth appearance, and lymphotropism. IMPC is associated with high incidence of lymphovascular invasion (LVI) and lymph node metastasis. Activated Wnt signaling has been implicated in the metastasis of other aggressive breast tumors, including triple-negative and basal-like carcinomas. In this study, we tested whether activated Wnt signaling could be detected in IMPC. Upon ligand binding, the central mediator of the Wnt pathway, β-catenin, accumulates in the cytosol and translocates to the nucleus where it forms a complex with lymphoid enhancer-binding factor 1 (LEF1) to regulate transcription. We performed immunostaining for β-catenin and LEF1 on a well-annotated cohort of 40 breast tumors and nodal metastases displaying micropapillary histopathology. Strong nuclear accumulation of β-catenin was not observed, however a dim cytosolic and/or nuclear accumulation of β-catenin was sometimes seen in IMPC and this expression pattern was significantly associated with nodal metastasis. β-catenin expression correlated with the upregulation of LEF1 in IMPC. LEF1 expression was detected in 26 of 40 (65%) cases and was specifically enriched at the invasive front of the tumor and in tumor clusters undergoing LVI. Detection of LEF1 expression in the primary tumor was associated with an increased rate of LVI, lymph node metastasis, and disease relapse. LEF1 and β-catenin expression levels were significantly higher in metastases compared with primary tumors. In summary, this study demonstrates an association between the upregulation of β-catenin/LEF1 and the metastasis of IMPC.

Identification of Germline Mutations in Genes Involved in Classic FAP in Patients from Northern Brazil

BACKGROUND

Colorectal cancer is a common cancer worldwide, with 5-10% of cases being hereditary. Familial adenomatous polyposis syndrome (FAP) is caused by germline mutations in the APC gene or rarely in the MUTYH gene.

PATIENTS AND METHODS

This work did not identify germline mutations in the MUTYH, NTHL1, POLD1 and POLE genes in 15 individuals belonging to five families with classic FAP, who had the mutation in the APC gene confirmed in a previous study. Our results support mutations in the APC gene as the main genetic contribution of classical FAP with severe phenotype. In the family that had the most aggressive form of the disease, we performed an array-based Comparative Genomic Hybridization analysis and identified the germinal loss of an allele of the NOTCH2 and BMPR2 genes in the mother (proband) and daughter. In order to validate the involvement of these genes in the other four families of this study, we analyzed the DNA copy number variation in the peripheral blood of the 15 participants.

RESULTS

FAP is a syndrome with considerable genetic and phenotypic heterogeneity and this phenomenon may explain the presence of secondary genetic alterations, such as the allelic loss of NOTCH2 and BMPR2 genes, found only in one family in this study. The CNV analysis confirmed that only the two members of the FAP2 family (patient 02H and 02F) had a deletion of these two genes, as the aCGH methodology had found. The other study participants did not show allelic loss for these two genes.

CONCLUSION

Validation in a larger number of families could confirm the presence of these new genetic alterations in classic FAP and improve understanding of the different types of aggressiveness of the disease.

Colorectal liver metastasis: molecular mechanism and interventional therapy

Colorectal cancer (CRC) is one of the most frequently occurring malignancy tumors with a high morbidity additionally, CRC patients may develop liver metastasis, which is the major cause of death. Despite significant advances in diagnostic and therapeutic techniques, the survival rate of colorectal liver metastasis (CRLM) patients remains very low. CRLM, as a complex cascade reaction process involving multiple factors and procedures, has complex and diverse molecular mechanisms. In this review, we summarize the mechanisms/pathophysiology, diagnosis, treatment of CRLM. We also focus on an overview of the recent advances in understanding the molecular basis of CRLM with a special emphasis on tumor microenvironment and promise of newer targeted therapies for CRLM, further improving the prognosis of CRLM patients.

Colon cancer cells secreted CXCL11 via RBP-Jκ to facilitated tumour-associated macrophage-induced cancer metastasis

Metastasis is the main cause of colon cancer‐related deaths. RBP‐Jκ is involved in colon cancer development, but its function in colon cancer metastasis is still unclear. Tumour‐associated macrophages are the main cell components in tumour microenvironments. Here, we aimed to determine the function of RBP‐Jκ in colon cancer metastasis and its underlying mechanisms for modulating interactions between colon cancer cell and tumour‐associated macrophages. Through bioinformation analysis, we found that RBP‐Jκ was overexpressed in colon cancer tissues and associated with advanced colon cancer phenotypes, macrophage infiltration and shorter survival overall as confirmed by our patients’ data. And our patients’ data show that RBP‐Jκ expression and tumour‐associated macrophages infiltration are associated with colon cancer metastasis and are independent prognostic factors for colon cancer patients. Tumour‐associated macrophages induced colon cancer cell migration, invasion and epithelial‐mesenchymal transition through secreting TGF‐β1. Colon cancer cells with high RBP‐Jκ expression induced the expression of TGF‐β1 in tumour‐associated macrophages by secreting CXCL11. Our research revealed that colon cancer cells secreted CXCL11 via overexpression of RBP‐Jκ to enhance the expression of TGF‐β1 in tumour‐associated macrophages to further promote metastasis of colon cancer cells.

Prognostic signatures and potential pathogenesis of eRNAs-related genes in colon adenocarcinoma

Enhancer RNAs (eRNAs) are a subclass of long noncoding RNAs (lncRNAs) that have a wide effect in human tumors. However, the systematic analysis of potential functions of eRNAs-related genes (eRGs) in colon cancer (CC) remains unexplored. In this study, a total of 8231 eRGs including 6236 protein-coding genes and 1995 lncRNAs were identified in CC based on the multiple resources. These eRGs showed higher expression level and stability compared to other genes. What's more, the functions of these eRGs were closely related to cancer. Then a prognostic prediction model with 12 eRGs signatures were obtained for colon adenocarcinoma (COAD) patients. ROC curves showed the AUCs were 0.81, 0.77, and 0.78 for 1-, 3-, and 5-year survival prediction, respectively. And the prognostic model also manifested good performance in the validation datasets. Besides, the expression levels of two prognostic signatures, TMEM220 and LRRN2, were verified to be significantly lower in CC tissues than in adjacent noncancerous tissues (p < .05). Finally, the distinct molecular features were characterized between the high- and low-risk group through multiomics analysis including DNA mutation and methylation. Our results show eRGs signatures based prognostic model has high accuracy and may provide innovative biomarkers in COAD.

EGCG inhibits growth of tumoral lesions on lip and tongue of K-Ras transgenic mice through the Notch pathway

Epigallocatechin-3-gallate (EGCG), the main active ingredient of green tea, exhibits low toxic side effect and versatile bioactivities, and its anti-cancer effect has been extensively studied. Most of the studies used cancer cell lines and xenograft models. However, whether EGCG can prevent tumor onset after cancer-associated mutations occur is still controversial. In the present study, Krt14-cre/ERT-Kras transgenic mice were developed and the expression of K-RasG12D was induced by tamoxifen. Two weeks after induction, the K-Ras mutant mice developed exophytic tumoral lesions on the lips and tongues, with significant activation of Notch signaling pathway. Administration of EGCG effectively delayed the time of appearance, decreased the size and weight of tumoral lesions, relieved heterotypic hyperplasia of tumoral lesions, and prolonged the life of the mice. The Notch signaling pathway was significantly inhibited by EGCG in the tumoral lesions. Furthermore, EGCG significantly induced cell apoptosis and inhibited the proliferation of tongue cancer cells by blocking the activation of Notch signaling pathway. Taken together, these results indicate EGCG as an effective chemotherapeutic agent for tongue cancer by targeting Notch pathway.

Overexpression of Notch2 enhances radiosensitivity via inhibition of the AKT/mTOR signaling pathway in nasopharyngeal carcinoma

Our previous study found that in nasopharyngeal carcinoma (NPC) cells, overexpression of Notch2 can inhibit epithelial-mesenchymal transition (EMT), which plays a vital role in mediating radiosensitivity. The purpose of this study was to explore the radiosensitizing efficacy of the Notch2 gene in NPC cells and its potential mechanism. We used the recombinant plasmid transfection technique to establish Notch2-overexpressing 5–8 F and CNE-2 NPC cells. Cell proliferation, radiosensitivity, apoptosis and cell cycle distribution were assessed by cell counting kit-8 (CCK-8) experiments, colony formation experiments and flow cytometry. The levels of proteins related to cell cycle, apoptosis, and the AKT/mTOR signaling pathway were evaluated by using Western blotting. The results suggested that Notch2 overexpression increased the radiosensitivity of NPC cells, with sensitizing enhancement ratios (SERs) of 1.24 (5–8 F cells) and 1.34 (CNE-2 cells). Flow cytometry indicated that the level of apoptosis and percentage of cells in G2/M-phase were highest in NPC cells overexpressing Notch2 and treated with radiotherapy compared to cells overexpressing Notch2 alone or administered radiotherapy alone. Western blotting showed that compared to that of cells treated with Notch2 overexpression or radiotherapy alone, the levels of γH2AX, Bax, Bcl-2, Cyclin D1 and AKT/mTOR signaling pathway-related proteins were modified in NPC cells overexpressing Notch2 and treated with radiotherapy. These findings showed that overexpression of Notch2 can increase the radiosensitivity of NPC cells by inhibiting the AKT/mTOR pathway.

Abbreviations

NPC: Nasopharyngeal carcinoma; EMT: Epithelial-mesenchymal transition; CCK8: Cell counting kit-8; EBV: Epstein-Barr virus; FBS: Fetal bovine serum; PE: Plating efficiency; SF: Survival fraction; SER: Sensitizing enhancement ratio; DSBs: DNA double-strand breaks

High expression of LEF1 correlates with poor prognosis in solid tumors, but not blood tumors: a meta-analysis

BACKGROUND

Previously published studies have indicated that lymphoid enhancer-binding factor 1 (LEF1) expression could be recognized as a valuable biomarker to evaluate clinical outcome for various types of malignant cancer, but the results remained controversial. Therefore, we conducted this meta-analysis to pool the published estimates and discuss the relationship of LEF1 expression with cancer prognosis.

METHODS

Five electronic databases Pubmed, Web of Science, Embase, CNKI, and Wanfang were systematically searched for eligible literatures. Hazard ratios (HRs) and 95% confidence intervals (CIs) from the included studies were combined to estimate the effect of LEF1 expression on cancer patients' survival.

RESULTS

Eleven original studies met the criteria and were enrolled for analysis. The results indicated that compared with patients in low LEF1 expression group, patients in high LEF1 expression group tended to have shorter overall survival (HR = 1.74, 95% CI: 1.06-2.86, P=0.029), especially for patients with solid tumors (HR = 2.39, 95% CI: 1.86-3.08, P=0.000).

CONCLUSIONS

Individual evidence about the prognostic value of LEF1 expression in human cancers was limited. Our meta-analysis supported the suggestion that elevated LEF1 expression could function as a promising biomarker to predict the clinical outcomes for malignant cancers, especially solid tumors. More high-quality clinical studies are warranted to highlight the prognostic value of LEF1 expression in human cancers.

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.

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.

Quercetin Inhibits Lef1 and Resensitizes Docetaxel-Resistant Breast Cancer Cells

Drug resistance is a major problem for breast cancer patients. Docetaxel is an anti-mitotic agent that serves as first line of treatment in metastatic breast cancer, however it is susceptible to cellular drug resistance. Drug-resistant cells are able to spread during treatment, leading to treatment failure and eventually metastasis, which remains the main cause for cancer-associated death. In previous studies, we used single-cell technologies and identified a set of genes that exhibit increased expression in drug-resistant cells, and they are mainly regulated by Lef1. Furthermore, upregulating Lef1 in parental cells caused them to become drug resistant. Therefore, we hypothesized that inhibiting Lef1 could resensitize cells to docetaxel. Here, we confirmed that Lef1 inhibition, especially on treatment with the small molecule quercetin, decreased the expression of Lef1 and resensitized cells to docetaxel. Our results demonstrate that Lef1 inhibition also downregulated ABCG2, Vim, and Cav1 expression and equally decreased Smad-dependent TGF-β signaling pathway activation. Likewise, these two molecules worked in a synergetic manner, greatly reducing the viability of drug-resistant cells. Prior studies in phase I clinical trials have already shown that quercetin can be safely administered to patients. Therefore, the use of quercetin as an adjuvant treatment in addition to docetaxel for the treatment of breast cancer may be a promising therapeutic approach.

Diverse LEF/TCF Expression in Human Colorectal Cancer Correlates with Altered Wnt-Regulated Transcriptome in a Meta-Analysis of Patient Biopsies

Aberrantly activated Wnt signaling causes cellular transformation that can lead to human colorectal cancer. Wnt signaling is mediated by Lymphoid Enhancer Factor/T-Cell Factor (LEF/TCF) DNA-binding factors. Here we investigate whether altered LEF/TCF expression is conserved in human colorectal tumor sample and may potentially be correlated with indicators of cancer progression. We carried out a meta-analysis of carefully selected publicly available gene expression data sets with paired tumor biopsy and adjacent matched normal tissues from colorectal cancer patients. Our meta-analysis confirms that among the four human LEF/TCF genes, LEF1 and TCF7 are preferentially expressed in tumor biopsies, while TCF7L2 and TCF7L1 in normal control tissue. We also confirm positive correlation of LEF1 and TCF7 expression with hallmarks of active Wnt signaling (i.e., AXIN2 and LGR5). We are able to correlate differential LEF/TCF gene expression with distinct transcriptomes associated with cell adhesion, extracellular matrix organization, and Wnt receptor feedback regulation. We demonstrate here in human colorectal tumor sample correlation of altered LEF/TCF gene expression with quantitatively and qualitatively different transcriptomes, suggesting LEF/TCF-specific transcriptional regulation of Wnt target genes relevant for cancer progression and survival. This bioinformatics analysis provides a foundation for future more detailed, functional, and molecular analyses aimed at dissecting such functional differences.

Inflammation-induced colon cancer in uPA-deficient mice is associated with a deregulated expression of Notch signaling pathway components

Notch is an evolutionarily conserved signaling pathway with an important role in development and cell fate determination. Deregulation of Notch signaling has been associated with several pathological conditions, including cancer. Acting as an oncogene in some types of cancers and as a tumor suppressor in other, Notch effects seem to be highly context-dependent in solid tumors. In the present study, we aimed to investigate gene expression levels of Notch pathway constituents, including ligands, receptors, and target genes, during the early stages of inflammation-associated intestinal carcinogenesis. To achieve so, we used our recently developed mouse model, in which colon cancer arises in the absence of urokinase-type plasminogen activator (uPA) due to colitis induced by dextran sodium sulfate (DSS) treatment. Among the cell surface components, ligands Jag1/Jag2 and receptors Notch1/Notch2 were found to be significantly upregulated in the uPA-deficient protumorigenic inflammatory microenvironment. Moreover, several intracellular Notch modulators, i.e. Hes1, Hey1, and Klf4, were also shown to be deregulated with inflammation, yet irrespective of uPA status. Sox9 transcription factor, however, was significantly downregulated in the uPA-deficient/DSS-treated mice that developed colon adenomas as compared to the wild-type/DSS-treated group with no neoplasia identified. The latter finding supports a tumor suppressive role of Sox9 in intestinal carcinogenesis. Our results point towards an early activation of Notch signaling pathway at the receptor-ligand level in inflammation-associated colon neoplasmatogenesis developed in the absence of uPA. Interestingly, such activation may not be accompanied by deregulation of downstream Notch-target genes, possibly due to the effects of other inter-related signaling pathways.

MicroRNA-16 is involved in the pathogenesis of pre-eclampsia via regulation of Notch2

In recent years, the role of microRNAs (miRNAs) in pre-eclampsia (PE) has been demonstrated, while the relevant mechanisms of miR-16 in PE await to be unearthed. Thus, the aim of this study is to explore whether miR-16 exerts its function in PE, and we assumed that miR-16 may be implicated in the occurrence of PE by adjusting the biological functions of trophoblast cells via modulating Notch2. Placental tissues of pregnant women with normal pregnancy and PE were collected to detect the expression of miR-16, Notch2, and Notch3. The effects of miR-16 and Notch2 on the biological functions of BeWo and JEG-3 cells were further determined. Expression of miR-16 and Notch2 in trophoblast cells was detected by reverse transcription quantitative polymerase chain reaction and western blot assay. Downregulated Notch2 and upregulated miR-16 and Notch3 were found in placental tissues of PE. There was a negative correlation between Notch2 and miR-16 expression (r = -0.769), and a positive correlation between Notch3 and miR-16 expression (r = 0.676; p < .05). Overexpression of miR-16 inhibited proliferation, migration, and invasion, and facilitated the apoptosis of BeWo and JEG-3 cells, but overexpression of Notch2 reversed this trend. Overexpression of miR-16 inhibited Notch2 expression in BeWo and JEG-3 cells, and Notch2 was the target gene of miR-16. Our study highlights that overexpression of miR-16 is involved in PE by regulating the biological functions of trophoblast cells via inhibition of Notch2. This paper provides a new idea for further study of the pathogenesis of PE.

FLI-06 Intercepts Notch Signaling And Suppresses The Proliferation And Self-renewal Of Tongue Cancer Cells

Purpose

The Notch signaling pathway plays an oncogenic role in tongue squamous cell carcinoma. The aim of this study was to inhibit the proliferation and self-renewal of tongue cancer cells by applying Notch signaling pathway inhibitor FLI-06 (Selleck, USA) and to lay a foundation for the clinically targeted treatment of tongue cancer for the future.

Methods

The mRNA expression level of Notch1 and the overall survival rate of patients with tongue cancer were examined by analyzing the TCGA database. Tongue cancer cells were treated with FLI-06. Cell proliferation, apoptosis, and stem cell self-renewal ability were tested in appropriate ways. A xenograft mouse model was established to observe tumor growth.

Results

From the TCGA data, we demonstrated that patients with high expression of Notch1 had a poor prognosis. We observed that the Notch signaling pathway inhibitor FLI-06 can restrain the activation of the Notch signaling pathway, decrease cell proliferation and induce cell apoptosis in vitro. The xenograft experiment indicated that intraperitoneal injection of FLI-06 inhibited tumor growth and increased cell apoptosis. FLI-06 suppressed both the mRNA and protein expression of Notch receptor and Notch targeted genes. We also observed that FLI-06 suppressed the proliferation of tongue cancer stem cells.

Conclusion

FLI-06 can block the proliferation and self-renewal of tongue cancer cells. It is inferred that this compound, which inhibits the Notch signaling pathway, may serve as a potential targeted drug for the treatment of tongue cancer in the clinic.

The transcription factor LEF1 promotes tumorigenicity and activates the TGF-β signaling pathway in esophageal squamous cell carcinoma

Background

Esophageal squamous cell carcinoma (ESCC) is the most difficult subtype of esophageal cancer to treat due to the paucity of effective targeted therapy. ESCC is believed to arise from cancer stem cells (CSCs) that contribute to metastasis and chemoresistance. Despite advances in diagnosis and treatment, the prognosis of ESCC patients remains poor.

Methods

In this study, we applied western blot, quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemistry, RNA-Seq analysis, luciferase reporter assay, Chip-qPCR, bioinformatics analysis, and a series of functional assays to show the potential role of LEF1 in regulating esophageal CSCs.

Results

We found that the overexpression of LEF1 was associated with aberrant clinicopathological characteristics and the poor prognosis of ESCC patients. In addition, the elevated expression of LEF1 and OV6 was significantly associated with aberrant clinicopathological features, and poor patient prognosis. Moreover, the overexpression of LEF1 was observed in esophageal CSCs purified by the magnetic sorting of adherent and spheroidal ESCC cells. The increased level of LEF1 in CSCs facilitated the expression of CSC markers, stem cell-like properties, resistance to chemotherapy, and tumorigenicity and increased the percentage of CSCs in ESCC samples. Conversely, the knockdown of LEF1 significantly diminished the self-renewal properties of ESCC. We showed that LEF1 played an important mechanical role in activating the TGF-β signaling pathway by directly binding to the ID1 gene promoter. A positive association between LEF1 and ID1 expression was also observed in clinical ESCC samples.

Conclusion

Our results indicate that the overexpression of LEF1 promotes a CSC-like phenotype in and the tumorigenicity of ESCC by activating the TGF-β signaling pathway. The inhibition of LEF1 might therefore be a novel therapeutic target to inactivate CSCs and inhibit tumor progression.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1296-7) contains supplementary material, which is available to authorized users.

MicroRNA-6852 suppresses glioma A172 cell proliferation and invasion by targeting LEF1

microRNA (miR)-6852 has been demonstrated to suppress the progression of gastric, colorectal and cervical cancer. The mechanism by which miR-6852 regulates glioma cells is yet to be elucidated. In the present study, reverse transcription-quantitative PCR analysis was used and the results demonstrated that miR-6852 expression was reduced in glioma tissues and cells. Cell counting kit-8 and transwell assay analysis indicated that proliferation, migration and invasion of A172 cells in the miR-6852 mimic group were lower than in the miR-NC group. Compared with the Inh-NC group, A172 cells of the Inh-miR-6852 group exhibited higher proliferation, migration and invasion. Additionally, the results indicated that lymphoid enhancer binding factor 1 (LEF1) was directly inhibited by miR-6852 and LEF1 expression was negatively correlated with miR-6852 expression in glioma tissues. Furthermore, the restoration of LEF1 reversed the effects of the miR-6852 mimics. The present findings suggested that miR-6852 inhibited glioma cells proliferation, migration and invasion by targeting the suppression of LEF1.

Inhibition of LEF1-Mediated DCLK1 by Niclosamide Attenuates Colorectal Cancer Stemness

PURPOSE

Niclosamide, an FDA-approved anthelmintic drug, has been characterized as a potent Wnt inhibitor that can suppress tumor growth and cancer stem-like cell (CSC) populations. However, the underlying molecular mechanisms remain poorly understood. This study aimed to examine how Wnt inhibition by niclosamide preferentially targets CSCs.

EXPERIMENTAL DESIGN

The mechanistic role of niclosamide in CSC inhibition was examined in public databases, human colorectal cancer cells, colorectal cancer xenografts, and azoxymethane/dextran sulfate sodium (AOM/DSS)-induced colorectal cancer model.

RESULTS

Niclosamide suppresses CSC populations and their self-renewal activities in colorectal cancer cells, and this CSC-targeting effect leads to irreversible disruption of tumor-initiating potential in vivo. Mechanistically, niclosamide downregulates multiple signaling components of the Wnt pathway, specifically lymphoid enhancer-binding factor 1 (LEF1) expression, which is critical for regulating stemness. Subsequently, we identified that the doublecortin-like kinase 1 (DCLK1)-B is a target of LEF1 and upregulates cancer stemness in colorectal cancer cells. We first documented that niclosamide blocks the transcription of DCLK1-B by interrupting the binding of LEF1 to DCLK1-B promoter. DCLK1-B depletion impairs cancer stemness resulting in reduced survival potential and increased apoptosis, thus sensitizing colorectal cancer to chemoradiation.

CONCLUSIONS

Disruption of the LEF1/DCLK1-B axis by niclosamide eradicates cancer stemness and elicits therapeutic effects on colorectal cancer initiation, progression, and resistance. These findings provide a preclinical rationale to broaden the clinical evaluation of niclosamide for the treatment of colorectal cancer.

An integrated study on TFs and miRNAs in colorectal cancer metastasis and evaluation of three co-regulated candidate genes as prognostic markers

Molecular alterations that occur in cancer have the potential to be considered as either cancer biomarkers or targeted therapies or even both. In the presented study, we aimed to elucidate the gene regulatory network of metastatic colorectal cancer using data acquired from microarrays to reach the most common DEGs in colorectal cancer metastasis and find their possible regulatory mechanism by DETFs and DEmiRs. In this regards, seven microarray datasets were employed to assess the most important DEGs, DETFs and DEmiRs in colorectal cancer metastasis. Afterward, GRN based on DETFs and DEmiRs were constructed. Also ARACNE algorithm was used to construct an accurate GRN. GRN was analyzed structurally and then, two DETFs (LEF1 and ETV4) and a less-well known DEG (FABP6) by real time qRT-PCR in 50 patients with colorectal cancer were quantified. The constructed GRN highlighted the importance of some DETFs and DEmiRs in colorectal cancer metastasis. Interestingly the gene expression analysis by qRT-PCR on three candidate genes (LEF1, ETV4 and FABP6) indicated that the three genes were co-expressed in tumor samples, and were significantly associated with metastasis in colorectal cancer. Therefore, our experimental results proved a part of our comprehensive data analysis and system biology results. In summary, according to our empirical study we found the importance of three candidate genes as the potent prognostic factors in colorectal cancer metastasis. Also our study in a holistic insight on gene regulatory mechanism revealed the importance of some gene regulatory factors (DETFs and DEmiRs) and their potential as prognostic factors and/or targets in molecular targeted therapies in colorectal cancer.

A novel microRNA identified in hepatocellular carcinomas is responsive to LEF1 and facilitates proliferation and epithelial-mesenchymal transition via targeting of NFIX

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers. It has been demonstrated that various cellular microRNAs (miRNAs) play an important role in HCC development. Here, we analyzed the miRNA profile in HCC tissues by Solexa sequencing, and we identified a novel microRNA, miR-HCC1, which is upregulated in HCC tissues. Further experiments showed that miR-HCC1 promoted HCC cell proliferation in vivo and in vitro, and migration and invasion resulting from the epithelial-mesenchymal transition (EMT) process. Nuclear factor I/X (NFIX), which inhibited cell proliferation, migration and invasion in HCC cells, was identified as a direct and functional target of miR-HCC1. Furthermore, lymphoid enhancer binding factor 1 (LEF1), a transcription factor, was shown to bind the promoter of miR-HCC1 and activate its expression. Collectively, these results indicate that LEF1-upregulated miR-HCC1 functions as an oncogene through the negative regulation of NFIX expression, which links the LEF1/miR-HCC1/NFIX axis to contribute to cell proliferation, migration and invasion of HCC cells and could provide novel insights into miRNA function and hepatocarcinogenesis and potential biomarkers for HCC.

Upregulation of NETO2 gene in colorectal cancer

BACKGROUND

Neuropilin and tolloid-like 2 (NETO2) is a single-pass transmembrane protein that has been shown primarily implicated in neuron-specific processes. Upregulation of NETO2 gene was also detected in several cancer types. In colorectal cancer (CRC), it was associated with tumor progression, invasion, and metastasis, and seems to be involved in epithelial-mesenchymal transition (EMT). However, the mechanism of NETO2 action is still poorly understood.

RESULTS

We have revealed significant increase in the expression of NETO2 gene and deregulation of eight EMT-related genes in CRC. Four of them were upregulated (TWIST1, SNAIL1, LEF1, and FOXA2); the mRNA levels of other genes (FOXA1, BMP2, BMP5, and SMAD7) were decreased. Expression of NETO2 gene was weakly correlated with that of genes involved in the EMT process.

CONCLUSIONS

We found considerable NETO2 upregulation, but no significant correlation between the expression of NETO2 and EMT-related genes in CRC. Thus, NETO2 may be involved in CRC progression, but is not directly associated with EMT.

Transcriptomic analyses reveal the underlying pro-malignant functions of PTHR1 for osteosarcoma via activation of Wnt and angiogenesis pathways

BACKGROUND

Increasing evidence has indicated parathyroid hormone type 1 receptor (PTHR1) plays important roles for the development and progression of osteosarcoma (OS). However, its function mechanisms remain unclear. The goal of this study was to further illuminate the roles of PTHR1 in OS using microarray data.

METHODS

Microarray data were available from the Gene Expression Omnibus database under the accession number GSE46861, including six tumors from mice with PTHR1 knockdown (PTHR1.358) and six tumors from mice with control knockdown (Ren.1309). Differentially expressed genes (DEGs) between PTHR1.358 and Ren.1309 were identified using the LIMMA method, and then, protein-protein interaction (PPI) network was constructed using data from STRING database to screen crucial genes associated with PTHR1. KEGG pathway enrichment analysis was performed to investigate the underlying functions of DEGs using DAVID tool.

RESULTS

A total of 1163 genes were identified as DEGs, including 617 downregulated (Lef1, lymphoid enhancer-binding factor 1) and 546 upregulated genes (Dkk1, Dickkopf-related protein 1). KEGG enrichment analysis indicated upregulated DEGs were involved in Renin-angiotensin system (e.g., Agt, angiotensinogen) and Wnt signaling pathway (e.g., Dkk1), while downregulated DEGs participated in Basal cell carcinoma (e.g., Lef1). A PPI network (534 nodes and 2830 edges) was constructed, in which Agt gene was demonstrated to be the hub gene and its interactive genes (e.g., CCR3, CC chemokine receptor 3; and CCL9, chemokine CC chemokine ligand 9) were inflammation related.

CONCLUSIONS

Our present study preliminarily reveals the pro-malignant effects of PTHR1 in OS cells may be mediated by activating Wnt, angiogenesis, and inflammation pathways via changing the expressions of the crucial enriched genes (Dkk1, Lef1, Agt-CCR3, and Agt-CCL9).

Notch and its oncogenic activity in human malignancies

BACKGROUND

Increasing evidence has demonstrated that Notch signaling is deregulated in human hematological malignancies and solid tumors. This signaling has a protumorigenic effect but may also act as a tumor suppressor. How induction of a single pathway gives rise to the opposite effects in different cell types is still unknown.

METHODS

This review article includes available data from peer-reviewed publications associated with the role of Notch signaling during cancer pathogenesis.

RESULTS

Numerous reports have indicated that alterations in Notch signaling and its oncogenic activity were originally associated with the pathogenesis of T‑cell acute lymphoblastic leukemia/lymphoma (T-ALL), an aggressive hematologic tumor affecting children and adolescents. The possibility that Notch could play a significant role in human breast cancer development comes from studies on mouse mammary tumor virus-induced cancer. Numerous findings over the past several years have indicated that alterations in Notch signaling are also responsible for ovarian cancer development. Mention should also be made of the connection between expression of Notch 3 and increased resistance to chemotherapy, which remains a major obstacle to successful treatment. Notch as an oncogenic factor is also involved in the development of colon cancer, lung carcinoma and Kaposi's sarcoma.

CONCLUSION

Notch is a binary cell fate determinant and its overexpression has been described as oncogenic in a wide array of human malignancies. This finding led to interest in therapeutically targeting this pathway, especially by the use of gamma-secretase inhibitors (GSIs) blocking the cleavage of Notch receptors at the cell membrane by the inhibition of Notch intracellular domain (NICD) releasing. Preclinical cancer models have revealed that GSIs suppress the growth of cancers such as pancreatic, breast and lung cancer.

FH535 Inhibits Proliferation and Motility of Colon Cancer Cells by Targeting Wnt/β-catenin Signaling Pathway

Aberrant Wnt/β-catenin pathway activation is frequently observed in human colorectal cancer (CRC) and has become a promising target for CRC treatment. Our study aimed to evaluate the effect of FH535, a small molecule inhibitor of Wnt/β-catenin pathway, on two colon cancer cell lines, HT29 and SW480. We found FH535 significantly inhibited colon cancer cell proliferation in vitro and induced cell cycle arrest. Moreover, FH535 inhibited colon cancer xenograft growth in vivo. Wound-healing assay and Transwell assay revealed that FH535 notably suppressed migration and invasion of SW480 cells. FH535 also repressed expression of cancer stem cell markers, CD24, CD44 and CD133 in HT29 cells. Real time-quantitative PCR and Western blotting revealed that targeting Wnt/β-catenin pathway using FH535 effectively downregulated target genes including cyclin D1 and survivin at mRNA and protein level, which contributed to the FH535-induced inhibitory effect on colon cancer cell proliferation. As mechanisms for suppressing cancer cell motility, FH535 downregulated expression of matrix metalloproteinase-7 and -9, Snail and vimentin. RNA sequencing revealed that FH535 prominently altered multiple biological pathways associated with DNA replication, cell cycle and metabolism. Our study highlights the anti-cancer effect of FH535 on colon cancer and presents its potential in colon cancer treatment.

LEF1 is preferentially expressed in the tubal-peritoneal junctions and is a reliable marker of tubal intraepithelial lesions

Recently it has been reported that serous tubal intraepithelial carcinoma (STIC), the likely precursor of ovarian/extra-uterine high-grade serous carcinoma, are frequently located in the vicinity of tubal-peritoneal junctions, consistent with the cancer-prone features of many epithelial transitional regions. To test if p53 (aka TP53)-signatures and secretory cell outgrowths (SCOUTs) also localize to tubal-peritoneal junctions, we examined these lesions in the fallopian tubes of patients undergoing salpingo-oophorectomy for sporadic high-grade serous carcinomas or as a prophylactic procedure for carriers of familial BRCA1 or 2 mutations. STICs were located closest to the tubal-peritoneal junctions with an average distance of 1.31 mm, while SCOUTs were not detected in the fimbriated end of the fallopian tube. As many epithelial transitional regions contain stem cells, we also determined the expression of stem cell markers in the normal fallopian tube, tubal intraepithelial lesions and high-grade serous carcinomas. Of those, LEF1 was consistently expressed in the tubal-peritoneal junctions and all lesions, independent of p53 status. All SCOUTs demonstrated strong nuclear expression of β-catenin consistent with the LEF1 participation in the canonical WNT pathway. However, β-catenin was preferentially located in the cytoplasm of cells comprising STICs and p53 signatures, suggesting WNT-independent function of LEF1 in those lesions. Both frequency of LEF1 expression and β-catenin nuclear expression correlated with the worst 5-year patient survival, supporting important role of both proteins in high-grade serous carcinoma. Taken together, our findings suggest the existence of stem cell niche within the tubal-peritoneal junctions. Furthermore, they support the notion that the pathogenesis of SCOUTs is distinct from that of STICs and p53 signatures. The location and discrete patterns of LEF1 and β-catenin expression may serve as highly sensitive and reliable ancillary markers for the detection and differential diagnosis of tubal intraepithelial lesions.

microRNA-219-5p inhibits epithelial-mesenchymal transition and metastasis of colorectal cancer by targeting lymphoid enhancer-binding factor 1

Aberrant expression of microRNAs (miRs) has been shown to play a critical role in the pathogenesis and progression of tumors. microRNA‐219‐5p (miR‐219‐5p) has been reported to be abnormally expressed in some types of human tumors. However, the mechanism between miR‐219‐5p and colorectal cancer (CRC) metastasis remains unclear. In the present study, miR‐219‐5p was found to be downregulated in CRC tissue compared with matched normal tissue. Through luciferase reporter assay, we demonstrated lymphoid enhancer‐binding factor 1 (LEF1) as a direct target of miR‐219‐5p. Overexpression of miR‐219‐5p could inhibit motility, migration and invasion of CRC cells, and inhibit epithelial‐mesenchymal transition (EMT). Furthermore, silencing LEF1 phenocopied this metastasis‐suppressive function. The recovery experiment showed that re‐expression of LEF1 rescued this suppressive effect on tumor metastasis and reversed the expression of EMT markers caused by miR‐219‐5p. Additionally, we demonstrated that miR‐219‐5p exerted this tumor‐suppressive function by blocking activation of the AKT and ERK pathways. Finally, a nude mice experiment showed that miR‐219‐5p reduced the lung metastasis ability of CRC cells. Taken together, our findings indicate that miR‐219‐5p inhibits metastasis and EMT of CRC by targeting LEF1 and suppressing the AKT and ERK pathways, which may provide a new antitumor strategy to delay CRC metastasis.

MiR-557 works as a tumor suppressor in human lung cancers by negatively regulating LEF1 expression

MicroRNAs play an important role in regulating post-transcriptional gene expression in the progression of various human cancers. In this study, we investigated the role of microRNA-557 in human lung cancer cells. The molecular mechanism of microRNA-557 was also clarified in the proliferation and invasion of human lung cancer cells. Our results showed microRNA-557 levels were obviously decreased in clinical lung cancer specimens and lung cancer cell lines. Cell viability of A549 and NCI-H460 cells transfected with microRNA-557 mimics was significantly decreased than those transfected with negative control mimics. MicroRNA-557 promoted cell death of A549 and NCI-H460 but did not affect the cell apoptosis of lung cancer cells. Overexpression of microRNA-557 inhibited cell invasion of A549 and NCI-H460 cells. TargetScan analysis showed that microRNA-557 might target 3' untranslated region of lymphocyte enhancement factor 1, and the western blotting results showed that transfection of microRNA-557 mimics significantly decreased the levels of lymphocyte enhancement factor 1 in A549 and H460 cells. MicroRNA-557 might work as a tumor suppressor by negatively regulating the expression of lymphocyte enhancement factor 1 in lung cancer cells.

Wnt signaling pathway protein LEF1 in cancer, as a biomarker for prognosis and a target for treatment

Transcription factors are regulatory proteins that either activate or repress the transcription of genes via binding to DNA regulatory sequences and regulating recruitment of transcriptional complexes. Lymphoid enhancer-binding factor 1 (LEF1), a member of the T-cell Factor (TCF)/LEF1 family of high-mobility group transcription factors, is a downstream mediator of the Wnt/β-catenin signaling pathway, but can also modulate gene transcription independently. LEF1 is essential in stem cell maintenance and organ development, especially in its role in epithelial-mesenchymal transition (EMT) by activating the transcription of hallmark EMT effectors including N-Cadherin, Vimentin, and Snail. Aberrant expression of LEF1 is implicated in tumorigenesis and cancer cell proliferation, migration, and invasion. LEF1's activity in particular cancer cell types, such as chronic lymphocytic leukemia (CLL), Burkitt lymphoma (BL), acute lymphoblastic leukemia (ALL), oral squamous cell carcinoma (OSCC), and colorectal cancer (CRC), makes it a valuable biomarker in predicting patient prognosis. Additionally, due to aberrant LEF1 activity resulting in cancer progression, knockdown and inhibition treatments designed to target LEF1 have proven effective in alleviating cancer growth, migration, and invasion in CLL, CRC, glioblastoma multiforme (GBM), and renal cell carcinoma (RCC). In prostate cancer cells, LEF1 promotes androgen receptor expression and activity in an androgen-independent manner, ultimately increasing prostate cancer growth regardless of androgen ablation therapy. In this review, we review LEF1 regulation, its role in tumorigenesis in several cancer types, and its clinical value as a biomarker for predicting prognoses and as a target for treatment.

The expressions of metadherin and LEF-1 in mucosa-associated lymphoid tissue lymphoma of ocular adnexal

AIM

To investigate the expressions of metadherin (astrocyte elevated gene-1, AEG-1) and lymphoid enhancer-binding factor-1 (LEF-1) in ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma.

METHODS

The expressions of AEG-1 and LEF-1 were detected on specimens harvested from patients suffering from MALT lymphoma and lymphadenosis of ocular adnexal in Ophthalmology Department, Affiliated Hospital of Qingdao University from 2000 to 2015 by immunohistochemical and polymerase chain reaction (PCR) analysis.

RESULTS

AEG-1 and LEF-1 expressions in MALT lymphoma was respectively higher than that in lymphadenosis, both by immunohistochemical and PCR analysis (P<0.05). Diversity of AEG-1 and LEF-1 expressions in different Ann Arbor clinical stages showed a statistically significant result (P<0.05). A positive relevance between AEG-1 and LEF-1 was observed in MALT ocular adnexal lymphoma (r=0.435, P=0.016).

CONCLUSION

The over expressions of AEG-1 and LEF-1 at the level of protein and mRNA participates in the tumorigenesis of ocular adnexal MALT lymphoma. They should act as a new biological marker for pathological diagnosis in the future.

Diagnostic Utility of Lymphoid Enhancer Binding Factor 1 Immunohistochemistry in Small B-Cell Lymphomas

OBJECTIVES

Recent studies have shown that lymphoid enhancer binding factor 1 (LEF1) is a useful marker for chronic lymphocytic B-cell leukemia (CLL)/small lymphocytic lymphoma. Yet, it is not still being widely used in a diagnostic setting. In this study, we document the experience with LEF1 immunohistochemistry during routine diagnostics.

METHODS

In total, 191 B-cell lymphoma cases from Hammersmith Hospital, Imperial College NHS Healthcare Trust (London, UK) were investigated by immunohistochemistry for LEF1 during routine diagnostic workup. These cases included both bone marrow trephines and lymph node biopsy specimens. The monoclonal antibody clone EPR2029Y was used.

RESULTS

LEF1 expression was strong and diffuse (>70% of cells) in most cases. Few CLL cases showed a staining in proliferation centers only. Seventy-seven of 80 CLL cases expressed LEF1. Other entities expressing LEF1 included one of 38 follicular lymphomas, two of 33 marginal zone lymphomas, and one diffuse large B-cell lymphoma with a background of follicular lymphoma grade 3B. Sensitivity for LEF1 for the diagnosis of CLL was 0.96, and specificity was 0.93.

CONCLUSIONS

In this study, we could demonstrate the diagnostic utility of LEF1. LEF1 is a sensitive and specific marker for CLL and is helpful in the diagnosis of diagnostically challenging small B-cell lymphomas.

NOTCH receptors in gastric and other gastrointestinal cancers: oncogenes or tumor suppressors?

Gastric cancer (GC) ranks the most common cancer types and is one of the leading causes of cancer-related death. Due to delayed diagnosis and high metastatic frequency, 5-year survival rate of GC is rather low. It is a complex disease resulting from the interaction between environmental factors and host genetic alterations that deregulate multiple signaling pathways. The Notch signaling pathway, a highly conserved system in the regulation of the fate in several cell types, plays a pivotal role in cell differentiation, survival and proliferation. Notch is also one of the most commonly activated signaling pathways in tumors and its aberrant activation plays a key role in cancer advancement. Whether Notch cascade exerts oncogenic or tumor suppressive function in different cancer types depends on the cellular context. Mammals have four NOTCH receptors that modulate Notch pathway activity. In this review, we provide a comprehensive summary on the functional role of NOTCH receptors in gastric and other gastrointestinal cancers. Increasing knowledge of NOTCH receptors in gastrointestinal cancers will help us recognize the underlying mechanisms of Notch signaling and develop novel therapeutic strategies for GC.

Notch2 is a crucial regulator of self-renewal and tumorigenicity in human hepatocellular carcinoma cells

The Notch pathway plays an important role in both stem cell biology and cancer. Notch2 was reported to be upregulated in human hepatocellular carcinoma (HCC) tissues. However, the biological function of Notch2 in human HCC cells has not yet been documented. The aim of this study was to investigate its possible function on the progression of human HCC cells. The expression of Notch2 was detected in four human HCC cell lines by western blotting. Next, Notch2 was knocked down by small interference RNA (siRNA) in human HCC cells. The role of Notch2 in human HCC cells was investigated by cell proliferation assay, colony formation assay, chemoresistance and xenograft formation assay. In the present study, western blotting revealed that the expression of Notch2 was upregulated in human HCC cell lines. Genetic depletion of Notch2 in HCC cells not only resulted in significantly inhibited proliferation, cell cycle progression and colony formation ability but also increased its sensitivity to 5-fluorouracil (5-FU) compared with controls. In addition, upregulation of Notch2 was discovered in CD90 positive HCC cells, CD90 is a marker of hepatic stem cells. Most importantly, knockdown of Notch2 in HCC cells impaired the tumor formation in vivo. Taken together, our findings indicate that Notch2 may confer stemness properties in HCC; downregulation of Notch2 inhibited the proliferation and tumor formation of HCC cells and increase their sensitivity to 5-FU, suggesting Notch2 as a potential therapeutic target for HCC.

The prognostic value of β-catenin and LEF-1 expression in patients with operable gastric carcinoma

AIM

The aim of this study is to evaluate the prognostic value of β-catenin and LEF-1 expression in patients with operable gastric cancer that receive adjuvant treatment and the relationship between demographic and histopathological variables.

MATERIAL AND METHOD

In this study, 82 gastric cancer patients treated with adjuvant treatment after surgery and followed in the Medical Oncology Department of Kocaeli University were included. β-catenin and LEF-1 expression were examined by immunuhistochemical analysis in paraffin embedded tumor tissues of the patients.

RESULTS

Median age was 56 (26-81) and follow up was 19 months (4-61). Performance status (ECOG) were 0-1 in all patients. Male/female ratio was 53/29 (64.6/35.4%). The median disease free survival (DFS) time was 17 months (SE: 3 95% CI: 11-23) and 3 years DFS rate was 39.7%. The median overall survival (OS) time was 28 months (SE: 4 95% CI: 20-36) and 3 years OS rate was 41.2%. There was no statistical correlation between β-catenin and LEF-1 expression and age, gender, performance status, tumor localization, T and N stage, lymphovascular, perinoral invasion, grade and operation type (>0.005). According to univariate analysis, we did not find significant effect of age, gender, T stage, lymphovascular, perinoral invasion, grade and operation type on overall survival (p>0.005). Good performance status (ECOG 0), tumor infiltration without diffuse type like linitis plastica, and lower N stage had positive effect on survival respectively (p=0.04, 0.033 and 0.005).

CONCLUSION

In this study group, we found that only N stage was an independent prognostic factor (<0.005). Demographic features of the patients, histopathological characteristics other than N stage, β-catenin and LEF-1 prognostic effects have not been shown.

microRNA-449a functions as a tumor suppressor in neuroblastoma through inducing cell differentiation and cell cycle arrest

microRNA-449a (miR-449a) has been identified to function as a tumor suppressor in several types of cancers. However, the role of miR-449a in neuroblastoma has not been intensively investigated. We recently found that the overexpression of miR-449a significantly induces neuroblastoma cell differentiation, suggesting its potential tumor suppressor function in neuroblastoma. In this study, we further investigated the mechanisms underlying the tumor suppressive function of miR-449a in neuroblastoma. We observed that miR-449a inhibits neuroblastoma cell survival and growth through 2 mechanisms--inducing cell differentiation and cell cycle arrest. Our comprehensive investigations on the dissection of the target genes of miR-449a revealed that 3 novel targets- MFAP4, PKP4 and TSEN15 -play important roles in mediating its differentiation-inducing function. In addition, we further found that its function in inducing cell cycle arrest involves down-regulating its direct targets CDK6 and LEF1. To determine the clinical significance of the miR-449a-mediated tumor suppressive mechanism, we examined the correlation between the expression of these 5 target genes in neuroblastoma tumor specimens and the survival of neuroblastoma patients. Remarkably, we noted that high tumor expression levels of all the 3 miR-449a target genes involved in regulating cell differentiation, but not the target genes involved in regulating cell cycle, are significantly correlated with poor survival of neuroblastoma patients. These results suggest the critical role of the differentiation-inducing function of miR-449a in determining neuroblastoma progression. Overall, our study provides the first comprehensive characterization of the tumor-suppressive function of miR-449a in neuroblastoma, and reveals the potential clinical significance of the miR-449a-mediated tumor suppressive pathway in neuroblastoma prognosis.

LEF-1 Regulates Tyrosinase Gene Transcription In Vitro

TYR, DCT and MITF are three important genes involved in maintaining the mature phenotype and producing melanin; they therefore participate in neural crest cell development into melanocytes. Previous studies have revealed that the Wnt signaling factor lymphoid enhancer-binding factor (LEF-1) can enhance DCT and MITF gene expression. However, whether LEF-1 also affects TYR gene expression remains unclear. In the present study, we found that LEF-1 regulated TYR transcription in vitro. LEF-1 overexpression increased TYR gene promoter activity, whereas LEF-1 knockdown by RNA interference significantly decreased TYR expression. Moreover, the core GTTTGAT sequence (-56 to -50) within the TYR promoter is essential for the effect of LEF-1 on TYR expression, and chromatin immunoprecipitation (ChIP) assay indicated that endogenous LEF-1 interacts with the TYR promoter. In addition, we observed a synergistic transactivation of the TYR promoter by LEF-1 and MITF. These data suggest that Wnt signaling plays an important role in regulating melanocyte development and differentiation.

LEF-1 is frequently expressed in colorectal carcinoma and not in other gastrointestinal tract adenocarcinomas: an immunohistochemical survey of 602 gastrointestinal tract neoplasms

LEF-1 is a DNA-binding protein that interacts with β-catenin and activates Wnt-responsive target genes. We analyzed the immunohistochemical expression of LEF-1 in 602 gastrointestinal and pancreatobiliary neoplasms in an attempt to (1) investigate the utility of LEF-1 immunohistochemistry as an ancillary marker in gastrointestinal/pancreatobiliary neoplasia, and (2) to perform a clinicopathologic and survival analysis of colorectal carcinoma stratified by LEF-1 expression. LEF-1 nuclear positivity was frequently identified in colorectal carcinoma (89/241, 37%) and only infrequently identified in other neoplasms: 11% esophagus/esophagogastric adenocarcinomas, 7% gastric adenocarcinomas, 1% pancreatic ductal adenocarcinomas, 4% pancreatic intraductal papillary mucinous neoplasms, and in no cases of appendiceal mucinous neoplasms or pancreatic mucinous cystic neoplasms. LEF-1 expression was identified in 35% of colorectal carcinomas that lacked CK20 and CDX2 expression. In colorectal carcinomas, LEF-1-positive tumors more frequently harbored KRAS mutations compared with LEF-1-negative tumors (39% vs. 16%, P=0.005). Patients with moderate/strong LEF-1-positive colorectal carcinoma had a trend of worse overall survival compared with patients with colorectal carcinomas with weak/negative LEF-1 expression (5 y overall survival, 31% vs. 47%, P=0.15). In conclusion, LEF-1 is most commonly expressed in colorectal carcinoma and infrequently observed in the upper gastrointestinal tract and pancreatic adenocarcinoma. LEF-1 Immunohistochemistry may be especially useful as an ancillary diagnostic marker in colorectal carcinomas, which lack the expression of both CK20 and CDX2. LEF-1 expression is associated with the presence of KRAS mutations and may have prognostic value as a trend of worse overall survival is seen in patients with LEF-1-positive colorectal carcinoma.