Chromosome Deletion ; Humans ; Kidney Neoplasms ; WAGR Syndrome/genetics* ; Wilms Tumor

OBJECTIVE: explore the expression of miR-155-5p in Wilms tumor and its effect in regulating the proliferation, migration and apoptosis of Wilms tumor cells. METHODS: Specimens of tumor tissues and paired adjacent tissues were obtained from 40 patients with Wilms tumor for detection of the expression levels of miR-155-5p using RT-qPCR. Wilms tumor cell line G401 was transfected with miR-155-5p mimics and miR-155-5p inhibitor to induce miR-155-5p over-expression and its inhibition, respectively, and the changes in the cell proliferation, migration and apoptosis were assessed using cell counting kit-8 (CCK-8), wound healing assay and fl ow cytometry. RESULTS: RT-qPCR showed that the expression of miR-155-5p decreased significantly in Wilms tumor tissues as compared with normal kidney tissues and was significantly associated with TNM stage ( < 0.05). In G401 cells, over-expression of miR-155-5p significantly inhibited the cell proliferation and migration and promoted cell apoptosis ( < 0.05), and down-regulation of miR-155-5p obviously enhanced the proliferation and migration and suppressed apoptosis of the cells ( < 0.05). CONCLUSIONS miR-155-5p is down-regulated in Wilms tumor and its expression level is correlated with TNM stage. miR-155-5p participates in the progression of Wilms tumor by inhibiting the proliferation and migration and promoting apoptosis of the tumor cells, and may serve as a novel biomarker for diagnosis, therapy and prognostic evaluation of Wilms tumor.
Apoptosis ; Cell Movement ; Cell Proliferation ; Humans ; Kidney Neoplasms ; genetics ; MicroRNAs ; genetics ; Neoplasm Invasiveness ; Wilms Tumor ; genetics

OBJECTIVEWilms' tumor (WT) is the most common malignant renal tumor in childhood. The WT1 gene located at 11p13 was identified in 1990 as a tumor suppressor gene important in the development in WT. The WT1 gene consists of 10 exons, with exons 1 to 6 encoding an N-terminal proline- and glutamine-rich transactivational domain, and exons 7 to 10 encoding a C-terminal zinc-finger domain involved in DNA binding. In China we know little about the frequency and genotype of WT1 mutations in Chinese WT patients. This study aimed to determine the frequency and genotype of WT1 mutations in children with nonsyndromic WT in China.

METHODSWe collected peripheral blood of WT patients treated in Beijing Children's Hospital. Genomic DNA of 54 WT patients was isolated from blood samples. All coding WT1 exons and their flanking intronic sequences were amplified by PCR method. The amplified PCR products from all individuals were then subjected to automatic DNA sequencing.

RESULTSFour different constitutional WT1 mutations were identified in four children. Three mutations are predicted to produce truncated protein. One mutation is missense. Of the four mutations, three had not been reported before. Patient 1 had a 1006 A > T transition in exon 7, which caused (336)Lys to become a stop codon (K336X). DNA sequence analyses in patient 2 indicated the point mutations in exon 9 which was a 1168 C > T substitution and caused (390)Arg to become a stop codon (R390X). It indicated a point mutations in exon 6 in patient 3 which was a 814 G > T substitution and resulted in (272)Glu to become a stop codon (E272X). In patient 4 there was a homozygous mutation in exon 10. The mutation was a 1228 A > G substitution and resulted in (410)Ser to become a Gly codon (S410G).

CONCLUSIONConstitutional WT1 mutations occur at a low frequency (7.4%) in Chinese patients with Wilms' Tumor. It is similar to the results of overseas study. Four WT1 gene mutations were confirmed, three were nonsense, one was missense.

Child ; Child, Preschool ; DNA Mutational Analysis ; Female ; Genes, Wilms Tumor ; Humans ; Infant ; Kidney Neoplasms ; genetics ; Male ; Mutation ; WT1 Proteins ; genetics ; Wilms Tumor ; genetics

Child, Preschool ; Chromosomes, Human, Pair 11 ; Female ; Humans ; Kidney Neoplasms ; genetics ; Ring Chromosomes ; Wilms Tumor ; genetics

OBJECTIVE: To study the expression of the Fra-1 gene in the peripheral blood of children with Wilms tumor and its clinical significance. METHODS: Fifty children pathologically diagnosed with Wilms tumor between December 2012 and January 2018 were enrolled as the case group, and 40 healthy children for physical examination were selected as the control group. Among the 45 children with Wilms tumor who were followed up, the children with continuous remission were included in the ideal efficacy group (n=33), and those with recurrence, metastasis or death were included in the poor efficacy group (n=12). Peripheral blood samples were collected from all subjects. Quantitative real-time PCR was used to measure the mRNA expression of Fra-1. RESULTS: The case group had significantly higher mRNA expression of Fra-1 in peripheral blood than the control group (P<0.05). In the case group, Fra-1 mRNA expression was significantly different between the individuals with and without distant metastasis and those with different TNM stages (P<0.05), but was not significantly different between the individuals with different sexes, ages, tumor diabetes, tumor locations and alpha-fetoprotein levels (P>0.05). The mRNA expression of Fra-1 was significantly lower in the ideal efficacy group than in the poor efficacy group (P<0.05). CONCLUSIONS Fra-1 may be involved in the development of Wilms tumor and plays a certain role in its development, invasion and metastasis, but the mechanism remains to be further studied.
Child ; Gene Expression Regulation, Neoplastic ; Humans ; Proto-Oncogene Proteins c-fos ; genetics ; Wilms Tumor ; genetics

OBJECTIVETo analyse the WT1 expression and its DNA methylation status of its promoter domain.

METHODThe expression of WT1 gene and its DNA methylation status were assayed in leukemia cell lines and normal peripheral blood mononuclear cells (PBMNC) by RT-PCR and MS-PCR.

RESULTSWT1 was overexpressed in HL60, K562 and KG1 leukemia cell lines, but not in U937 and PBMNC. Methylation of WT1 promoter was not observed in HL60 cells.

CONCLUSIONDNA methylation of WT1 gene promotor did not inhibit its expression. Other mechanisms may appear to regulate the WT1 expression.

Cell Line, Tumor ; DNA Methylation ; Genes, Wilms Tumor ; Humans ; Leukemia ; genetics ; Polymerase Chain Reaction ; Promoter Regions, Genetic

OBJECTIVETo investigate the changes in methylation levels of the promoters of the tumor suppressor gene Wilms' tumor gene on the X-chromosome (WTX) and its possible role in gastric cancer.

METHODSWTX promoter methylation levels were detected in 20 pairs of specimens of gastric cancer and matched normal tissues and in 3 gastric cancer cell lines (MGC803, SCG7901, and BGC823) using the Sequenom MassARRAY quantitative analysis system. The gastric cancer cell line BGC823 was treated with 5-aza-2'-deoxycytidine (5-aza-dC) for demethylation and the changes in the level of WTX promoter methylation were investigated.

RESULTSWTX promoter methylation levels were very low and showed no significant differences among normal gastric tissues, gastric cancer tissues and the 3 gastric cancer cell lines. In BGC823 cells, treatment with 5-aza-dC did not obviously affect the promoter methylation levels of WTX.

CONCLUSIONHigh methylation levels of WTX promoters are rare in gastric cancer.

Cell Line, Tumor ; Chromosomes, Human, X ; DNA Methylation ; Genes, Wilms Tumor ; Humans ; Promoter Regions, Genetic ; Stomach Neoplasms ; genetics ; metabolism

Child ; Humans ; Case-Control Studies ; East Asian People ; Genetic Predisposition to Disease/genetics* ; Methyltransferases/genetics* ; Polymorphism, Genetic ; Wilms Tumor/pathology*

BACKGROUNDDNA hypomethylation of long interspersed nuclear elements-1 (LINEs-1) occurs during carcinogenesis, whereas information addressing LINE-1 methylation in Wilms tumor (WT) is limited. The main purpose of our study was to quantify LINE-1 methylation levels and evaluate their relationship with relative telomere length (TL) in WT.

METHODSWe investigated LINE-1 methylation and relative TL using bisulfite-polymerase chain reaction (PCR) pyrosequencing and quantitative PCR, respectively, in 20 WT tissues, 10 normal kidney tissues and a WT cell line. Significant changes were analyzed by t-tests.

RESULTSLINE-1 methylation levels were significantly lower (P < 0.05) and relative TLs were significantly shorter (P < 0.05) in WT compared with normal kidney. There was a significant positive relationship between LINE-1 methylation and relative TL in WT (r = 0.671, P = 0.001). LINE-1 Methylation levels were significantly associated with global DNA methylation (r = 0.332, P < 0.01). In addition, relative TL was shortened and LINE-1 methylation was decreased in a WT cell line treated with the hypomethylating agent 5-aza-2'-deoxycytidine compared with untreated WT cell line.

CONCLUSIONThese results suggest that LINE-1 hypomethylation is common and may be linked to telomere shortening in WT.

Cell Line, Tumor ; Child ; Child, Preschool ; DNA Methylation ; genetics ; Female ; Humans ; Long Interspersed Nucleotide Elements ; genetics ; Male ; Polymerase Chain Reaction ; Telomere ; genetics ; Wilms Tumor ; genetics

BACKGROUNDWilms' tumor (nephroblastoma) is the most common pediatric kidney cancer. Only one Wilms' tumor gene is known, WT1 at 11p13, which is mutated in 5% - 10% of Wilms' tumors. Recently, mutations were reported in WTX at Xq11.1 in Wilms' tumors. This study investigated the mutation proportion, type, and distribution in WTX and WT1 in children with Wilms' tumor. The role of WTX/WT1 in the development of Wilms' tumor, and the relationship between clinical phenotype and genotype, were also studied.

METHODSWilms' tumor specimens (blood samples from 70 patients and tumor tissue samples from 52 patients) were used. A long fragment of WTX and 10 exons and intron sequences of WT1 were amplified by polymerase chain reaction (PCR) from extracted genomic DNA and sequenced. A chi-square test compared the difference between the WTX mutation group and the no mutation group. The relationship between the mutations and clinical phenotype was analyzed.

RESULTSWTX mutations were found in 5/52 tumor tissues and in 2/70 peripheral blood samples (five cases in total, all point mutations). Two patients had a WTX mutation in both samples. WT1 mutations were found in 2/52 tumor tissues and in 4/70 peripheral blood samples (five cases in total, all point mutations). One patient had a WT1 mutation in both samples. Ten cases had WTX or WT1 mutation (19.2% of Wilms' tumors). No overlapping WTX and WT1 mutations were found. No significant differences in clinical parameters were found between patients with and without a WTX mutation.

CONCLUSIONSWTX mutations occur early in Wilms' tumor development, but at a low proportion. There was no evidence that WTX is the main cause of Wilms' tumor. Clinical parameters of patients with WTX mutations are not related to the mutation, indicating a limited impact of WTX on tumor progression. WTX and WT1 mutations occur independently, suggesting a relationship between their gene products.

Adaptor Proteins, Signal Transducing ; genetics ; Child, Preschool ; Female ; Humans ; Male ; Mutation ; Tumor Suppressor Proteins ; genetics ; WT1 Proteins ; genetics ; Wilms Tumor ; genetics