PURPOSE: Childhood cancer is closely related to the mutation of tumor suppressor gene. The mutant gene may evoke congenital anomaly and development of cancer. The common solid tumors in childhood are Wilms' tumor, retinoblastoma and neuroblastoma. The cytogenetic study has been performed. The cytogentic study revealed structural abnormality of chromosome in Wilms' tumor and retinoblastoma. The oncogene and mutation of tumor suppressor gene are applicable to the study of carcinogenesis of childhood cancer. We studied to investigate the expression of p53, Rb and WT-1 in Wilms' tumor and retinoblastoma. METHODS: Immunohistochemical study has been performed to investigate the expression of p53, Rb and WT-1 in 7 cases of Wilms' tumor and 4 cases of retinoblastoma of childhood cancer. RESULTS: The positive reaction for p53, Rb and WT-l was seen in the nuclei of tumor cells. The positive reaction for tumor suppressor gene products in Wilms' tumor showed that p53 (mutant type) was 57.1%, Rb 85.7%, WT-l 28.6%. The immunohistochemistry for tumor suppressor gene products in retinoblastoma revealed that p53 protein (mutant type) was seen in all the cases, but Rb and WT-l protein were not seen. CONCLUSION: These results suggested that Wilms' tumor may be partially related with mutation of p53, Rb and WT-1, and retinoblastoma may have a relationship with mutation of p53 and Rb.
Carcinogenesis ; Cytogenetics ; Genes, Tumor Suppressor ; Immunohistochemistry ; Neuroblastoma ; Oncogenes ; Retinoblastoma ; Wilms Tumor

Congenital aniridia is a rare ocular malformation that presents with severe hypoplasia of the iris and various ocular manifestations. Most cases of congenital aniridia are known to be related to mutations in the paired box gene-6 (PAX6), which is an essential gene in eye development. Herein, we report a familial case of autosomal dominant congenital aniridia with four affected members in 3 consecutive generations and describe the detailed ophthalmologic findings for one of these members. As expected, mutational analysis revealed a nonsense mutation (p.Ser122*) in the PAX6 gene. Thus, our findings reiterate the importance of PAX6 mutations in congenital aniridia.
Aniridia* ; Codon, Nonsense ; Family Characteristics ; Genes, Essential ; Humans ; Iris ; WAGR Syndrome ; Wilms Tumor

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

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

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

Acute Disease ; Blast Crisis ; genetics ; Genes, Retinoblastoma ; Genes, Wilms Tumor ; Humans ; Leukemia ; genetics ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; pathology ; Polymerase Chain Reaction ; U937 Cells

PURPOSE : In a recent study of Wilms' tumors, a new X chromosome gene, Wilms' tumor gene on the X chromosome (WTX), was discovered that was found to harbor small deletions and point mutations. The WTX protein negatively regulates Wnt/beta-catenin signaling, and is considered to be a tumor suppressor gene. One of the questions about the WTX gene is whether the genetic alterations of the WTX gene are specific only to Wilms' tumors. The aim of this study was to explore whether the WTX gene mutation is a characteristic of human non-small cell lung cancer (NSCLC). MATERIALS AND METHODS : In the current study, we analyzed the part of the WTX gene encoding the N-terminal of WTX, where most of the WTX point mutations have been detected in Wilms' tumors. Forty-eight NSCLC tissues were analyzed by a single-strand conformation polymorphism assay and DNA sequencing. RESULTS : SSCP analysis revealed no evidence of somatic mutations in the DNA sequences encoding the N-terminal of the WTX gene in the 48 NSCLC tissues. CONCLUSION : The data presented here indicate that the WTX gene may not be somatically-mutated in human NSCLCs, and suggest that NSCLCs may not utilize mutational events of the WTX gene in the process of pathogenesis
Base Sequence ; Carcinoma, Non-Small-Cell Lung ; Genes, Tumor Suppressor ; Humans ; Point Mutation ; Polymorphism, Single-Stranded Conformational ; Sequence Analysis, DNA ; Wilms Tumor ; X Chromosome

To study the expression and significance of WT1 gene in patients with myelodysplastic syndrome (MDS) and acute leukemia (AL), RT-PCR was applied to monitor WT1 gene expression in 22 patients with MDS and in 69 patients with AL. The results showed that the positive rate of WT1 mRNA in MDS-RA and MDS-RAS was lower than that in MDS-RAEB and MDS-RAEB-t (10% versus 91.7%, P < 0.01). WT1 mRNA could be expressed in all subtype of AL, It was detected in 69% of newly diagnosed and relapsed patients, and in 12.5% patients CR. There was no difference at the relative expression level between newly diagnosed AL patients and relapsed patients, while the relative level of WT1 in MDS-RAEB and MDS-RAEB-t was lower than that in newly diagnosed AL. The CR rate in AML patients with positive expression was lower than that in patients with negative expression (41% versus 78%, P /= 1 had lower CR rate (18%) than those with relative level < 1 (55%). It is concluded that the expression of WT1 gene in patients with MDS-RAEB and RAEB-t was higher than that in patients with RA and RAS. The detection of WT1 gene may be useful for assessing disease progress of patients with MDS. The expression of WT1 gene and its expression level have associated with the prognosis of newly diagnosed patients with AL, that WT1 gene may be an independent prognostic factor in AML.
Adolescent ; Adult ; Aged ; Child ; Female ; Genes, Wilms Tumor ; Humans ; Leukemia, Myeloid, Acute ; genetics ; Male ; Middle Aged ; Myelodysplastic Syndromes ; genetics ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; genetics

This study was aimed to investigate the expression level of Wilms' tumor 1( WT1) gene in hematologic neoplasm (leukemia, multiple myeloma and lymphoma) patients and its clinical significance. Real-time quantitative polymerase chain reaction (RQ-PCR) was used to detect the copy number of WT1 gene and reference gene (ALB) in bone marrow cells of 228 patients with hematologic neoplasm in our hospital. The gene expression level was determined by using the ratio of the copy number of WT1 gene and reference gene. The results showed that the WT1 expression level between male and female patients was not statistically significantly different (P > 0.05). All the patients were divided into 3 groups: the group aged under 19, the group aged between 19-50, and the group aged over 50; the WT1 expression level among the three groups were not statistically significantly different (P > 0.05) . The above-mentioned patients were redivided into the groups aged under 45 and over 45, the difference between them was not statistically significant (P > 0.05). The difference of WT1 expression level between newly diagnosed patients and treated patients with hematologic neoplasm was statistically significant (P < 0.01), but no statistically significant difference of WT1 expression was found (P > 0.05) at each stage within 3 years after treatment, however, among them the difference between newly diagnosed leukemia patients and treated leukemia patients was very statistically significant (P < 0.01), while the difference between newly diagnosed and treated non-leukemia patients was not statistically significant (P > 0.05). The expression difference of WT1 between leukemia and non-leukemia patients was very statistically significant (P < 0.01), the difference between the newly diagnosed leukemia and non-leukemia patients also was very statistically significant (P < 0.01). The difference of WT1 expression between treated leukemia and non-leukemia patients was not statistically significant (P > 0.05). It is concluded that the WT1 expression level in leukemia patients can be a reliable marker to evaluate the prognosis of newly diagnosed leukemia and the curative effect for minimal residual disease. No WT1 expression difference has been found before and after treatment among the patients with non-leukemia, such as multiple myeloma and lymphoma, therefore, which should be furtherly explored.
Aged ; Female ; Gene Expression Regulation, Neoplastic ; Genes, Wilms Tumor ; Hematologic Neoplasms ; genetics ; Humans ; Leukemia ; genetics ; Male ; Neoplasm, Residual ; Polymerase Chain Reaction ; Prognosis

BACKGROUNDThis study was designed to quantitatively measure WT-1 expression levels in patients with chronic myelogenous leukemia (CML) and acute lymphoblastic leukemia (ALL) during follow-up and to clarify the value of WT-1 as a molecular marker in minimal residual disease monitoring.

METHODSThe TaqMan quantitative real-time RT-PCR method was established by using cloned WT-1 cDNA or synthesized oligonucleotides resembling WT-1 cDNA fragments in limit dilution as template until a stable and reliable standard curve was obtained. In a 25-month follow-up, the transcriptional levels of WT-1, Bcr-Abl, and Abl gene, were quantitatively measured in bone marrow cells from 25 CML or acute lymphoblastic leukemia (ALL) patients with the Ph chromosome. In addition, the expression of these genes in 40 samples of normal peripheral blood was also examined using the same method. The ratios of WT-1/Abl and Bcr-Abl/Abl were both plotted, and the two expression patterns were compared as well as their clinical significance.

RESULTSThe levels of WT-1 expression in normal peripheral blood were detectable. In CML and Ph positive ALL patients, WT-1 expression levels changed in parallel with the Bcr-Abl expression pattern as the disease progressed or responded to effective treatment.

CONCLUSIONWT-1 expression provides a novel molecular marker in addition to Bcr-Abl for monitoring minimal residual disease (MRD) and targeting therapy in Ph chromosome-positive leukemia patients.

Adult ; Aged ; Female ; Follow-Up Studies ; Genes, Wilms Tumor ; Genes, abl ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; genetics ; Male ; Middle Aged ; Neoplasm, Residual ; Philadelphia Chromosome ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; methods