Lymphoid enhancer-binding factor 1 (LEF1), a key downstream effector of Wnt/β-catenin signal transduction pathway, plays a crucial role in the maintenance, proliferation and differentiation of normal hematopoietic stem/progenitor cells through regulating the transcription of its target genes. Aberrant LEF1 expression has been documented in a variety of leukemias, and implicated in the prediction of prognosis. Nevertheless, discrepancies exist regarding the expression level and clinical implication of LEF1 in different types of leukemias, suggesting LEF1 might exert distinct roles in different types of leukemia. In the present article, recent research advances of the relationship of LEF1 and regulation of hematopoiesis and leukemogenesis are reviewed.
Acute Disease ; Cell Differentiation ; Humans ; Leukemia ; Lymphoid Enhancer-Binding Factor 1 ; Prognosis ; Wnt Signaling Pathway ; beta Catenin

Lymphoid enhancer factor 1 (LEF1) is a key transcription factor in Wingless-type (Wnt) pathway. The present study was aimed to explore the genetic mutation and expression of LEF1, and their clinical significance in adult patients with acute lymphocytic leukemia (ALL). Genomic DNA was amplified and sequenced to detect the mutation of LEF1 in 131 newly diagnosed adult patients with ALL. Quantitative PCR (qPCR) was performed to detect the expression of LEF1. Moreover, the correlations between mutations and expression of LEF1 with clinical characteristics were analyzed. The results showed that the frequency of LEF1 mutation in adult ALL was 3.1% (4/131) and all of them were point mutations located in exon 2 and 3; the median white blood cell count and median percentage of blasts at diagnosis were significantly higher in LEF1 high expression group than in low expression group (70.6 × 10⁹/L vs 26.2 × 10⁹/L)(P = 0.010); (81.0% vs 57.0%) (P = 0.014); in addition, the percentage of patients with Philadelphia chromosome positive and patients in high-risk group significantly increased in LEF1 high expression group compared with that in low expression group (66.7% vs 36.5%) (P = 0.038); (79.2% vs 56.2%) (P = 0.044). It is concluded that high expression of LEF1 may play an important role on development of adult ALL.
Adult ; Exons ; Gene Expression Regulation, Leukemic ; Humans ; Lymphoid Enhancer-Binding Factor 1 ; genetics ; Mutation ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; genetics

To develop an enzyme-linked immunosorbent assay (ELISA)-based high throughput screening (HTS) method for β-catenin/Lef1 interaction antagonists screening, Escherichia coli Rosetta (DE3) competent cells were transformed with β-catenin-pET-30a(+) plasmid. β-catenin protein was expressed after induction and purified using affinity chromatography. The biological activity of purified β-catenin was further analyzed by GST Pulldown assay. The β-catenin/GST-Lef1 binding model was established using ELISA principle, and the ELISA-based HTS method was further optimized through determination of an optimal coated concentration of GST-Lef1 and working concentration of β-catenin. The results showed that β-catenin protein was successfully expressed and purified. The GST Pulldown assay demonstrated a perfect biological activity for purified β-catenin. Subsequently, the ELISA-based HTS method was performed using 10 μg/mL GST-Lef1 and 6 μg/mL β-catenin, with the Z factor of 0.76. Taken together, we have successfully developed a simple, robust and reliable ELISA-based HTS method for screening of novel Wnt inhibitors targeting β-catenin/Lef1 interaction.
Antineoplastic Agents ; Enzyme-Linked Immunosorbent Assay ; High-Throughput Screening Assays ; Lymphoid Enhancer-Binding Factor 1 ; beta Catenin

OBJECTIVETo construct a eukaryotic fluorescent expression vector of truncated lymphoid enhancer-binding factor 1 (LEF-1) gene and investigate its effect on the proliferation and apoptosis of human colonic carcinoma cell line SW480.

METHODSTruncated LEF-1 gene was obtained by PCR and DNA recombination from human lymphoid node cDNA library. The PCR product of LEF-1 gene was inserted into the plasmid pMD-18T and sequenced. The truncated LEF-1 gene was inserted into the eukaryotic expression plasmid pcDNA3.1 and fused with mRFP for tracing. Using Lipofectamine 2000, the plasmid pcDNA3.1-LEF-1-mRFP was transfected into Hela cells and detected by Western blotting and fluorescence activated cell sorting (FACS). The changes in the growth, proliferation and apoptosis of the SW480 cells were observed after transfection with the plasmids.

RESULTSThe truncated LEF-1 gene was successfully cloned. After transfection with the plasmid pcDNA3.1-LEF-1-mRFP, the Hela cells expressed the product of LEF-1 as detected by Western blotting and FACS. The growth and proliferation of SW480 cells was inhibited and the cell apoptosis increased after transfection with the plasmid pcDNA3.1-LEF-1-mRFP, which also caused cell cycle arrest in G0/1 phase.

CONCLUSIONThe eukaryotic expression fluorescent vector pcDNA3.1-LEF-1-mRFP has been constructed and expressed in eukaryotic cell line successfully. The truncated LEF-1 protein expressed in the transfected SW480 cells results in inhibition of the cell growth and proliferation with increased cell apoptosis and cell cycle arrest in G0/1 phase.

Cell Line, Tumor ; Colonic Neoplasms ; metabolism ; pathology ; Fluorescence ; Genetic Vectors ; genetics ; Humans ; Lymphoid Enhancer-Binding Factor 1 ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics

Kawasaki disease (KD) is an acute febrile vasculitis predominately affecting infants and children. The dominant incidence age of KD is from 6 months to 5 years of age, and the incidence is unusual in those younger than 6 months and older than 5 years of age. We tried to identify genetic variants specifically associated with KD in patients younger than 6 months or older than 5 years of age. We performed an age-stratified genome-wide association study using the Illumina HumanOmni1-Quad BeadChip data (296 cases vs. 1,000 controls) and a replication study (1,360 cases vs. 3,553 controls) in the Korean population. Among 26 candidate single nucleotide polymorphisms (SNPs) tested in replication study, only a rare nonsynonymous SNP (rs4365796: c.1106C>T, p.Thr369Met) in the lymphoid enhancer binding factor 1 (LEF1) gene was very significantly associated with KD in patients younger than 6 months of age (odds ratio [OR], 3.07; p(combined) = 1.10 × 10⁻⁵), whereas no association of the same SNP was observed in any other age group of KD patients. The same SNP (rs4365796) in the LEF1 gene showed the same direction of risk effect in Japanese KD patients younger than 6 months of age, although the effect was not statistically significant (OR, 1.42; p = 0.397). This result indicates that the LEF1 gene may play an important role as a susceptibility gene specifically affecting KD patients younger than 6 months of age.
Asian Continental Ancestry Group ; Child ; Genome-Wide Association Study ; Humans ; Incidence ; Infant ; Lymphoid Enhancer-Binding Factor 1 ; Mucocutaneous Lymph Node Syndrome* ; Polymorphism, Single Nucleotide ; Vasculitis

BACKGROUND: In acute leukemia patients, several successful methods of expression profiling have been used for various purposes, i.e., to identify new disease class, to select a therapeutic target, or to predict chemo-sensitivity and clinical outcome. In the present study, we tested the peripheral blood of 47 acute leukemia patients in an attempt to identify differentially expressed genes in AML and ALL using a Korean-made 10K oligo-nucleotide microarray. METHODS: Total RNA was prepared from peripheral blood and amplified for microarray experimentation. SAM (significant analysis of microarray) and PAM (prediction analysis of microarray) were used to select significant genes. The selected genes were tested for in a test group, independently of the training group. RESULTS: We identified 345 differentially expressed genes that differentiated AML and ALL patients (FWER < 0.05). Genes were selected using the training group (n=35) and tested for in the test group (n=12). Both training group and test group discriminated AML and ALL patients accurately. Genes that showed relatively high expression in AML patients were deoxynucleotidyl transferase, pre-B lymphocyte gene 3, B-cell linker, CD9 antigen, lymphoid enhancer-binding factor 1, CD79B antigen, and early B-cell factor. Genes highly expressed in ALL patients were annexin A 1, amyloid beta (A4) precursor protein, amyloid beta (A4) precursor-like protein 2, cathepsin C, lysozyme (renal amyloidosis), myeloperoxidase, and hematopoietic prostaglandin D2 synthase. CONCLUSION: This study provided genome wide molecular signatures of Korean acute leukemia patients, which clearly identify AML and ALL. Given with other reported signatures, these molecular signatures provide a means of achieving a molecular diagnosis in Korean acute leukemia patents.
Amyloid ; Antigens, CD79 ; Antigens, CD9 ; B-Lymphocytes ; Cathepsin C ; Diagnosis ; DNA Nucleotidylexotransferase ; Gene Expression* ; Genome ; Humans ; Leukemia* ; Leukemia, Myeloid, Acute ; Lymphoid Enhancer-Binding Factor 1 ; Muramidase ; Peroxidase ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Precursor Cells, B-Lymphoid ; Prostaglandin D2 ; RNA ; Transcriptome*

The Wnt signaling pathway and its key component β-catenin have critical roles in the development of diseases such as tumors in mammals. However, little has been reported about involvement of the Wnt/β-catenin signaling pathway in canine mammary tumors (CMTs). The present study detected expression of 30 Wnt signaling pathway-related genes in CMTs; the results are potentially useful for molecular-based diagnosis of CMTs and the development of new targeted therapies. Significant upregulations of dickkopf-1 protein, secreted frizzled-related sequence protein 1 (SFRP1), frizzled 3, β-catenin, and lymphoid enhancer-binding factor 1 (LEF1) were detected in highly malignant CMTs compared to levels in normal mammary gland tissues; moreover, highly significant upregulation of WNT5A was observed in low malignancy CMTs. Downregulation was only detected for SFRP4 in malignant CMT samples. The subcellular location of β-catenin and cyclin D1 in 100 CMT samples was investigated via immunohistochemical analysis, and significantly increased expressions of β-catenin in cytoplasm and cyclin D1 in nuclei were revealed. Western blotting analysis revealed that the expression of β-catenin and LEF1 increased in in the majority of CMT samples. Taken together, the results provide important evidence of the activation status of the Wnt pathway in CMTs and valuable clues to identifying biomarkers for molecular-based diagnosis of CMT.
beta Catenin ; Biomarkers ; Blotting, Western ; Cyclin D1 ; Cytoplasm ; Diagnosis ; Down-Regulation ; Immunochemistry* ; Lymphoid Enhancer-Binding Factor 1 ; Mammals ; Mammary Glands, Human ; Polymerase Chain Reaction* ; Up-Regulation ; Wnt Signaling Pathway

OBJECTIVETo explore the effect of high glucose on proliferation of bone marrow stromal stem cells through Wnt/Β-catenin pathway.

METHODSBone marrow stormal cells were obtained from the mandible of Wistar rats and stimulated with different concentrations of glucose (5.5 and 16.5 mmol/L). Cell proliferation was evaluated with methyl thiazolyl tetrazolium assay (1, 3, 5, and 7 d)and cell cycle analysis by flow cytometry (5 d). Β-catenin and cyclin D1 protein levels were determined by Western blot. The mRNA expression of lymphoid enhancer binding factor-1 (LEF-1) and cyclin D1 were tested by real-time polymerase chain reaction.

RESULTSThe results of methyl thiazolyl tetrazolium assay indicated that the optical density values of two different concentrations of the glucose had no statistical difference on day 1 (P=0.700). On days 3, 5, and 7, the optical density values of the 16.5 mmol/L group were significantly lower than those in the 5.5 mmol/L group (P=0.006, P=0.002, and P=0.003). Cell cycle analysis indicated that high glucose concentration could reduced the progression from phase G1 to S, and the proliferation index values of the 16.5 mmol/L group were significantly lower than those of the 5.5 mmol/L group (P=0.014). The Β-catenin and cyclin D1 levels were lower in the 16.5 mmol/L group when compared with the 5.5 mmol/L group. High glucose condition also reduced the mRNA expressions of LEF-1 and cyclin D1.

CONCLUSIONHigh glucose can inhibit the proliferation of bone marrow stormal cells by suppressing the expressions of Β-catenin, LEF-1, and cyclin D1 in the Wnt/Β-catenin pathway.

Animals ; Bone Marrow Cells ; cytology ; Cell Proliferation ; drug effects ; Cyclin D1 ; metabolism ; Glucose ; pharmacology ; Lymphoid Enhancer-Binding Factor 1 ; metabolism ; Male ; Mandible ; cytology ; Mesenchymal Stromal Cells ; cytology ; Rats ; Rats, Wistar ; Wnt Signaling Pathway ; beta Catenin ; metabolism

OBJECTIVE: To determine the inhibitory effect of miRNA-381 on renal carcinoma invasion and to explore the underlying mechanisms.
 METHODS: After up-regulation of miRNA-381, the inhibitory effect of miR-381 on cell invasion was investigated. We screened the target genes of miRNA-381 in a database (starBase) through combination of five programs including targetscan, picTar, RNA22, PITA and miRanda. Then, the predicted targeting genes were verified by the dual luciferase reporter assay. We also examined the expression of miRNA-381 and its target genes in renal cancer cells and tissues.
 RESULTS: Transfection and up-regulation of miRNA-381 resulted in a significant decrease in trans-membrane cell numbers and the ability of renal cell invasion. Bioinformatics analysis showed that CREB binding protein (CBP), β-catenin and lymphoid enhancer binding factor-1 (LEF-1) were the potential targets of miRNA-381. In the luciferase reporter gene system, co-transfection of miRNA-381 with the 3'UTR of wild-type target gene led to a significant decrease in luciferase activity. The expression of miRNA-381 was decreased in various renal cancer cells, and it was particularly lower in highly metastatic cell lines (786-OHM). On the contrary, the expression levels of miRNA-381 target genes (CBP, β-catenin and LEF-1) were significantly increased in cells and tissues.
 CONCLUSION MiRNA-381 can inhibit cell invasion in renal cancer by block the function of CBP, β-catenin and LEF-1.
3' Untranslated Regions ; CREB-Binding Protein ; metabolism ; Carcinoma, Renal Cell ; pathology ; Cell Line, Tumor ; Computational Biology ; Gene Expression Regulation, Neoplastic ; Humans ; Kidney Neoplasms ; pathology ; Lymphoid Enhancer-Binding Factor 1 ; metabolism ; MicroRNAs ; genetics ; Neoplasm Invasiveness ; genetics ; Transfection ; Up-Regulation ; beta Catenin ; metabolism

BACKGROUND AND OBJECTIVERadioresistant cells in esophageal cancer is one of the important reasons for the local failure of radiotherapy. In recent years, some researchers used gene chip technology to screen the differentially expressed genes between parental and radioresistant human esophageal cancer cells. But there were some problems in these studies, for example comparing cells at only one time interval, and genetic background not matching. In this study, we selected 3 different pairs of parental and radioresistant human esophageal cancer cells, and compared the gene expression profiles by cDNA microarray at 3 time intervals to identify and analyze the differentially expressed genes between parental and radioresistant human esophageal cancer cells.

METHODSWe compared the gene expression profiles between parental cells (TE13, Seg-1, Kyse170) and radioresistant cells (TE13R, Seg-1R, Kyse170R) before, and at 8 h and 24 h after irradiation with a cDNA microarray consisting of 48 000 genes (Human Genome). We identified differentially expressed genes by Pathway and GO analyses, and verified the differentially expressed genes LEF1 and CTNNB1 by RT-PCR.

RESULTSA total of 460, 451, and 397 differentially expressed genes were found before, and at 8 h and 24 h after irradiation. After Pathway and GO analyses, 14 differentially expressed genes, participating in cell growth, apoptosis, cell cycle regulation, gene repair and signal transmission, were selected to further research. LEF1 and CTNNB1 were verified by RT-PCR, and the results were consistent with those of cDNA microarray.

CONCLUSIONSThe WNT signal pathway may be an important pathway participating in the formation of radioresistance of esophageal cancer cells. LEF1 and CTNNB1 may be the important genes causing the esophageal cancer cell radioresistance.

Carcinoma, Squamous Cell ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; radiation effects ; Esophageal Neoplasms ; genetics ; metabolism ; pathology ; Gene Expression Regulation, Neoplastic ; Humans ; Lymphoid Enhancer-Binding Factor 1 ; metabolism ; Oligonucleotide Array Sequence Analysis ; Radiation Tolerance ; Transcriptome ; Wnt Signaling Pathway ; radiation effects ; beta Catenin ; metabolism