WT1

Gene Summary

Gene:WT1; Wilms tumor 1
Aliases: GUD, AWT1, WAGR, WT33, NPHS4, WIT-2, EWS-WT1
Location:11p13
Summary:This gene encodes a transcription factor that contains four zinc-finger motifs at the C-terminus and a proline/glutamine-rich DNA-binding domain at the N-terminus. It has an essential role in the normal development of the urogenital system, and it is mutated in a small subset of patients with Wilms tumor. This gene exhibits complex tissue-specific and polymorphic imprinting pattern, with biallelic, and monoallelic expression from the maternal and paternal alleles in different tissues. Multiple transcript variants have been described. In several variants, there is evidence for the use of a non-AUG (CUG) translation initiation codon upstream of, and in-frame with the first AUG. Authors of PMID:7926762 also provide evidence that WT1 mRNA undergoes RNA editing in human and rat, and that this process is tissue-restricted and developmentally regulated. [provided by RefSeq, Mar 2015]
Databases:OMIM, VEGA, HGNC, Ensembl, GeneCard, Gene
Protein:Wilms tumor protein
HPRD
Source:NCBIAccessed: 18 March, 2015

Ontology:

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

The Wilms' tumour suppressor gene (WT1) gene was first cloned in 1989. The protein it produces is thought to have an important role in normal kidney and gonad development. Mutations in this gene are found in children with familial (inherited) Wilms' tumour and in children with WAGR genitourinary malformations. However, only about 10% of sporadic (non-familial) Wilms' tumours contain a WT1 mutation.

WT1 is overexpressed in a wide range of hematological and solid malignancies, including acute leukaemias where WT1 expression has prosgnostic significance.

Therapeutic use: WT1 is proving to be a promising tumor antigen for the development of a new class of universal cancer vaccines. There are a number of cancer vaccine trials using WT1-targeted immunotherapy in a range of cancers.


Research Indicators

Publications Per Year (1990-2015)
Graph generated 18 March 2015 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

Tag cloud generated 18 March, 2015 using data from PubMed, MeSH and CancerIndex

Specific Cancers (14)

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

Entity Topic PubMed Papers
Wilms TumourWT1 mutation in Wilms Tumour
Mutations of the WT1 gene are found in children with familial (inherited) Wilms' tumour and in children with WAGR genitourinary malformations. However, only about 10% of sporadic (non-familial) Wilms' tumours contain a WT1 mutation.
View Publications511
Acute Myeloid Leukaemia (AML)WT1 and Acute Myeloid Leukaemia
WT1 is aberrantly over-expressed in AML.
View Publications191
-WT1 use in Cancer Immunotherapy Therapy
In a National Cancer Institute prioritization project, WT1 was ranked first in a list of 75 cancer antigens (Cheever et al, 2009) promoting clinical trials of WT1-targeted therapies. There are a number of cancer vaccine trials using WT1-targeted immunotherapy in a range of cancers.Several features of WT1 make it a promising target for immunotherapy (Van Driessche et al, 2012). It is highly expressed in several types of hematological malignancies and solid tumors. Studies using WT1 antisense oligonucleotides have indicated growth inhibition in leukemic and solid tumour cells using treatment with WT1 antisense oligonucleotides. Moreover, WT1 has been shown to have a negative influence on differentiation, but promotes proliferation of progenitor cells. The WT1 protein exhibits high T-cell antigenicity, and loss of WT1 expression can lead to cessation of proliferation or death of cancer cells.
View Publications111
Childhood LeukaemiaWT1 expression in Childhood Leukemia View Publications82
Denys-Drash SyndromeWT1 abnormalities in Denys-Drash Syndrome
Denys-Drash Syndrome is a rare condition characterised by renal failure, pseudohermaphroditism, and Wilms' tumor. It is associated with abnormalities of the WT1 gene.
View Publications76
MesotheliomaWT1 expression in MesotheliomaPrognostic View Publications74
Myelodysplastic SyndromesWT1 expression in Myelodysplastic Syndromes View Publications69
-WT1 and Residual Disease View Publications64
Ovarian CancerWT1 expression in Ovarian Cancer View Publications37
WAGR SyndromeWT1 deletions in WAGR Syndrome
Wilms tumor, aniridia, genitourinary anomalies and mental retardation syndrome (WAGR) is a contiguous gene syndrome caused by deletions at chromosome 11p13 in a region containing the WT1 and PAX6 genes.
View Publications30
Lung Cancer, Non-Small CellWT1 expression in Non-Small Cell Lung CancerPrognostic Epigenetics
A number of studies have shown that WT1 expression is relevant in NSCLC. For exampple Nikolaidis et al (2012) identified hypermethylation at p16, TERT, WT1, and RASSF1 as having diagnostic significance in a case-control study of NSCLC. Hayashi et al. (2012) found that low WT1 expression predicted poor prognosis in patients with NSCLC.
View Publications24
-WT1 Polymorphism rs16754 in AML
Ho wr al (2014) reported a relationship between prognosis in childhood AML, WT1 expression and WT1 SNP rs16754. In SNP- patients, high WT1 expression predicted decreased survival in univariate, but not multivariate, analysis, due to a preponderance of high-risk cyto/molecular abnormalities in the highest expression group.
View Publications15
Desmoplastic Small Round Cell Tumourt(11;22)(p13;q12): EWSR1-WT1 in Desmoplastic Small Round Cell Tumour
DSRCT is a rare and an aggressive malignancy characterised by a translocation of the EWSR1 and WT1 genes, resulting in a EWSR1-WT1 fusion protein.
View Publications11

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

Latest Publications: WT1 (cancer-related)

Ud Din N, Pekmezci M, Javed G, et al.
Low-grade small round cell tumor of the cauda equina with EWSR1-WT1 fusion and indolent clinical course.
Hum Pathol. 2015; 46(1):153-8 [PubMed] Related Publications
We report a case of a longstanding, large tumor involving spinal nerve roots of the cauda equina. The tumor showed small round cells arranged in nests and cords and immunophenotypic features of a glomus tumor, along with infrequent mitoses and a low Ki-67 labeling index, but exhibited some rosette-like structures, with focal CD99 and Neu-N expression. Subsequent molecular analysis showed the presence of an EWSR1-WT1 gene fusion by fluorescence in situ hybridization, which was confirmed by reverse- transcriptase polymerase chain reaction. To our knowledge, this is the first case reported with EWSR1-WT1 fusion in a small round blue cell tumor with smooth muscle differentiation and an indolent course.

Wu C, Wang Y, Xia Y, et al.
Wilms' tumor 1 enhances Cisplatin-resistance of advanced NSCLC.
FEBS Lett. 2014; 588(24):4566-72 [PubMed] Related Publications
Wilms' tumor 1 (WT1) is an oncogene that has been correlated with tumor progression, bad prognosis and chemo-resistance in Non-Small-Cell lung cancer (NSCLC). Here, we found that WT1 expression is significantly higher in NSCLCs than in benign controls, and that Cisplatin-resistant patients display a notable increase in WT1 expression following relapse. In vitro, WT1 levels were associated with the IC50 of NSCLC cells and increased along with treatment time and dose of Cisplatin. Furthermore, WT1 enhanced Major Vault Protein (MVP) transcription via binding to its promoter. Therefore, WT1 may be a potential therapeutic target for solving resistance.

Sinha S, Thomas D, Yu L, et al.
Mutant WT1 is associated with DNA hypermethylation of PRC2 targets in AML and responds to EZH2 inhibition.
Blood. 2015; 125(2):316-26 [PubMed] Free Access to Full Article Related Publications
Acute myeloid leukemia (AML) is associated with deregulation of DNA methylation; however, many cases do not bear mutations in known regulators of cytosine guanine dinucleotide (CpG) methylation. We found that mutations in WT1, IDH2, and CEBPA were strongly linked to DNA hypermethylation in AML using a novel integrative analysis of The Cancer Genome Atlas data based on Boolean implications, if-then rules that identify all individual CpG sites that are hypermethylated in the presence of a mutation. Introduction of mutant WT1 (WT1mut) into wild-type AML cells induced DNA hypermethylation, confirming mutant WT1 to be causally associated with DNA hypermethylation. Methylated genes in WT1mut primary patient samples were highly enriched for polycomb repressor complex 2 (PRC2) targets, implicating PRC2 dysregulation in WT1mut leukemogenesis. We found that PRC2 target genes were aberrantly repressed in WT1mut AML, and that expression of mutant WT1 in CD34(+) cord blood cells induced myeloid differentiation block. Treatment of WT1mut AML cells with short hairpin RNA or pharmacologic PRC2/enhancer of zeste homolog 2 (EZH2) inhibitors promoted myeloid differentiation, suggesting EZH2 inhibitors may be active in this AML subtype. Our results highlight a strong association between mutant WT1 and DNA hypermethylation in AML and demonstrate that Boolean implications can be used to decipher mutation-specific methylation patterns that may lead to therapeutic insights.

Chou SC, Tang JL, Hou HA, et al.
Prognostic implication of gene mutations on overall survival in the adult acute myeloid leukemia patients receiving or not receiving allogeneic hematopoietic stem cell transplantations.
Leuk Res. 2014; 38(11):1278-84 [PubMed] Related Publications
Several gene mutations have been shown to provide clinical implications in patients with acute myeloid leukemia (AML). However, the prognostic impact of gene mutations in the context of allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains unclear. We retrospectively evaluated the clinical implications of 8 gene mutations in 325 adult AML patients; 100 of them received allo-HSCT and 225 did not. The genetic alterations analyzed included NPM1, FLT3-ITD, FLT3-TKD, CEBPA, RUNX1, RAS, MLL-PTD, and WT1. In patients who did not receive allo-HSCT, older age, higher WBC count, higher lactate dehydrogenase level, unfavorable karyotype, and RUNX1 mutation were significantly associated with poor overall survival (OS), while CEBPA double mutation (CEBPA(double-mut)) and NPM1(mut)/FLT3-ITD(neg) were associated with good outcome. However, in patients who received allo-HSCT, only refractory disease status at the time of HSCT and unfavorable karyotype were independent poor prognostic factors. Surprisingly, RUNX1 mutation was an independent good prognostic factor for OS in multivariate analysis. The prognostic impact of FLT3-ITD or NPM1(mut)/FLT3-ITD(neg) was lost in this group of patients receiving allo-HSCT, while CEBPA(double-mut) showed a trend to be a good prognostic factor. In conclusion, allo-HSCT can ameliorate the unfavorable influence of some poor-risk gene mutations in AML patients. Unexpectedly, the RUNX1 mutation showed a favorable prognostic impact in the context of allo-HSCT. These results need to be confirmed by further studies with more AML patients.

Hedley C, Sriraksa R, Showeil R, et al.
The frequency and significance of WT-1 expression in serous endometrial carcinoma.
Hum Pathol. 2014; 45(9):1879-84 [PubMed] Related Publications
Serous endometrial carcinoma is an aggressive type of endometrial carcinoma. Wilms tumor gene 1 (WT-1) is commonly expressed in ovarian serous carcinomas and considered a diagnostic marker of these tumors. However, it is generally believed that WT-1 is rarely expressed by endometrial serous carcinoma. The aim of this study was to evaluate the frequency and significance of WT-1 expression in endometrial serous carcinoma. We studied the expression of WT-1 in formalin-fixed, paraffin-embedded tumor sections from 77 cases of endometrial serous carcinoma. Thirty-four tumors showed positive expression for WT-1 (44%). There was a statistically significant association between the presence of WT-1 expression and disease-free survival (DFS), where patients with tumors expressing WT-1 had a shorter DFS compared with those with no WT-1 expression (P = .031; median DFS, 15 and 38 months, respectively). By multivariate Cox regression analysis, DFS was independent from other clinicopathological data (tumor stage, presence of lymphovascular space invasion, cervical involvement, and extrauterine spread), indicating that WT-1 expression is independently associated with DFS. Our study shows that WT-1 is expressed in a considerable percentage of endometrial serous carcinomas, suggesting a role for WT-1 in the pathology of these tumors. This has therapeutic significance, as WT-1 is an emerging target for immunotherapy. Moreover, our results show that WT-1 has prognostic value, being predictive of DFS. As a potential prognostic marker and therapeutic target, we recommend that WT-1 expression should be included in histopathologic reports of endometrial serous carcinoma.

Tian F, Yourek G, Shi X, Yang Y
The development of Wilms tumor: from WT1 and microRNA to animal models.
Biochim Biophys Acta. 2014; 1846(1):180-7 [PubMed] Related Publications
Wilms tumor recapitulates the development of the kidney and represents a unique opportunity to understand the relationship between normal and tumor development. This has been illustrated by the findings that mutations of Wnt/β-catenin pathway-related WT1, β-catenin, and WTX together account for about one-third of Wilms tumor cases. While intense efforts are being made to explore the genetic basis of the other two-thirds of tumor cases, it is worth noting that, epigenetic changes, particularly the loss of imprinting of the DNA region encoding the major fetal growth factor IGF2, which results in its biallelic over-expression, are closely associated with the development of many Wilms tumors. Recent investigations also revealed that mutations of Drosha and Dicer, the RNases required for miRNA generation, and Dis3L2, the 3'-5' exonuclease that normally degrades miRNAs and mRNAs, could cause predisposition to Wilms tumors, demonstrating that miRNA can play a pivotal role in Wilms tumor development. Interestingly, Lin28, a direct target of miRNA let-7 and potent regulator of stem cell self-renewal and differentiation, is significantly elevated in some Wilms tumors, and enforced expression of Lin28 during kidney development could induce Wilms tumor. With the success in establishing mice nephroblastoma models through over-expressing IGF2 and deleting WT1, and advances in understanding the ENU-induced rat model, we are now able to explore the molecular and cellular mechanisms induced by these genetic, epigenetic, and miRNA alterations in animal models to understand the development of Wilms tumor. These animal models may also serve as valuable systems to assess new treatment targets and strategies for Wilms tumor.

Sugita S, Arai Y, Tonooka A, et al.
A novel CIC-FOXO4 gene fusion in undifferentiated small round cell sarcoma: a genetically distinct variant of Ewing-like sarcoma.
Am J Surg Pathol. 2014; 38(11):1571-6 [PubMed] Related Publications
Differential diagnosis of small round cell sarcomas (SRCSs) grouped under the Ewing sarcoma family of tumors (ESFT) can be a challenging situation for pathologists. Recent studies have revealed that some groups of Ewing-like sarcoma show typical ESFT morphology but lack any EWSR1-ETS gene fusions. Here we identified a novel gene fusion, CIC-FOXO4, in a case of Ewing-like sarcoma with a t(X;19)(q13;q13.3) translocation. The patient was a 63-year-old man who had an asymptomatic, 30-mm, well-demarcated, intramuscular mass in his right posterior neck, and imaging findings suggested a diagnosis of high-grade sarcoma. He was treated with complete resection and subsequent radiotherapy and chemotherapy. He was alive without local recurrence or distant metastasis 6 months after the operation. Histologic examination revealed SRCS with abundant desmoplastic fibrous stroma suggesting a desmoplastic small round cell tumor. Immunohistochemical analysis showed weak to moderate and partial staining for MIC2 (CD99) and WT1, respectively. High-throughput transcriptome sequencing revealed a gene fusion, and the genomic rearrangement between the CIC and FOXO4 genes was identified by fluorescence in situ hybridization. Aside from the desmoplastic stroma, the CIC-FOXO4 fusion sarcoma showed morphologic and immunohistochemical similarity to ESFT and Ewing-like sarcomas, including the recently described CIC-DUX4 fusion sarcoma. Although clinicopathologic analysis with additional cases is necessary, we conclude that CIC-FOXO4 fusion sarcoma is a new type of Ewing-like sarcoma that has a specific genetic signature. These findings have important implications for the differential diagnosis of SRCS.

Abdelzaher E, Abdallah DM
Expression of mesothelioma-related markers in meningiomas: an immunohistochemical study.
Biomed Res Int. 2014; 2014:968794 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Meningiomas are common intracranial tumors. Recently, histogenetic and phenotypic similarities between meningiomas and mesotheliomas have been proposed. We were interested in whether these similarities are reflected on the immunohistochemical level, which would add new potentially diagnostic markers for meningiomas.
METHODS: The expression of mesothelioma-related markers (D2-40, Calretinin, Keratin 5/6, WT1, and Methotheioma-Ab1) was investigated in 87 cases of meningiomas and compared to EMA expression.
RESULTS: 73.6% of meningioma cases were grade I, 20.7% were grade II, and 5.7% were grade III. 83.9% of meningioma cases were classical and 16.1% had special nonmeningothelial features. D2-40 was expressed in 37.9% of cases and was significantly restricted to classical meningiomas. Calretinin and WT1 were negative while Keratin 5/6 and Mesothelioma-Ab1 were weakly expressed in classical variants (5.7% and 3.4%, resp.). EMA was consistently expressed in all cases. Its expression was significantly higher than that of mesothelioma-related markers; this held true also when D2-40 expression was considered separately.
CONCLUSIONS: Mesothelioma-related markers are not extensively expressed in meningiomas, a finding that argues against their proposed histogenetic and phenotypic similarities. Compared to EMA, the significantly lower expression of mesothelioma-related markers and their restricted expression to classical meningioma variants hamper their potential future use as diagnostic markers for meningioma.

Bachas C, Schuurhuis GJ, Reinhardt D, et al.
Clinical relevance of molecular aberrations in paediatric acute myeloid leukaemia at first relapse.
Br J Haematol. 2014; 166(6):902-10 [PubMed] Related Publications
Outcome for relapsed paediatric acute myeloid leukaemia (AML) remains poor. Strong prognostic factors at first relapse are lacking, which hampers optimization of therapy. We assessed the frequency of molecular aberrations (FLT3, NRAS, KRAS, KIT, WT1 and NPM1 genes) at first relapse in a large set (n = 198) of relapsed non-French-American-British M3, non-Down syndrome AML patients that received similar relapse treatment. We correlated molecular aberrations with clinical and biological factors and studied their prognostic relevance. Hotspot mutations in the analysed genes were detected in 92 out of 198 patients (46·5%). In 72 of these 92 patients (78%), molecular aberrations were mutually exclusive for the currently analysed genes. FLT3-internal tandem repeat (ITD) (18% of total group) mutations were most frequent, followed by NRAS (10·2%), KRAS (8%), WT1 (8%), KIT (8%), NPM1 (5%) and FLT3-tyrosine kinase domain (3%) mutations. Presence of a WT1 aberration was an independent risk factor for second relapse (Hazard Ratio [HR] = 2·74, P = 0·013). In patients who achieved second complete remission (70·2%), WT1 and FLT3-ITD aberrations were independent risk factors for poor overall survival (HR = 2·32, P = 0·038 and HR = 1·89, P = 0·045 respectively). These data show that molecular aberrations at first relapse are of prognostic relevance and potentially useful for risk group stratification of paediatric relapsed AML and for identification of patients eligible for personalized treatment.

Toska E, Roberts SG
Mechanisms of transcriptional regulation by WT1 (Wilms' tumour 1).
Biochem J. 2014; 461(1):15-32 [PubMed] Related Publications
The WT1 (Wilms' tumour 1) gene encodes a zinc finger transcription factor and RNA-binding protein that direct the development of several organs and tissues. WT1 manifests both tumour suppressor and oncogenic activities, but the reasons behind these opposing functions are still not clear. As a transcriptional regulator, WT1 can either activate or repress numerous target genes resulting in disparate biological effects such as growth, differentiation and apoptosis. The complex nature of WT1 is exemplified by a plethora of isoforms, post-translational modifications and multiple binding partners. How WT1 achieves specificity to regulate a large number of target genes involved in diverse physiological processes is the focus of the present review. We discuss the wealth of the growing molecular information that defines our current understanding of the versatility and utility of WT1 as a master regulator of organ development, a tumour suppressor and an oncogene.

Pasupuleti SK, Katari V, Lokanathan S, et al.
Novel frame shift mutations ('A' deletion) observed in exon 9 of Wilms' tumor (WT1) gene in a patient reported with glomerulosclerosis.
Gene. 2014; 546(1):63-7 [PubMed] Related Publications
Wilms' tumor-suppressor gene-1 (WT1) is a transcription factor that contains four zinc-finger motifs at the C-terminus and plays a crucial role in kidney and gonad development. We have identified primitive glomeruloid formation using immunohistochemistry in a patient who was clinically diagnosed with a Wilms' tumor. In order to understand the involvement of mutations in the WT1 gene, the genomic DNA was isolated from peripheral blood of the patient (18/F). Exon 9 of the WT1 gene was amplified and sequenced. The obtained sequence was BLAST searched against the transcript variants (TV) of the WT1 gene. An amplified exon 9 sequence of the WT1 gene showing similarity with exon 9 of TV-A, F and exon 10 of TV-B, D and E with a deletion of single nucleotide 'A' causing frame shift in the 4th zinc finger domain of the WT1 protein resulted in Wilms' tumor condition. The deletion position is variable with different transcript variants and they are present at: for TV-A c.1592delA, p.468, for TV-F c.1053delA, p.259, for TV-B c.1643delA, p.485, for TV-D c.1652 delA, p.488, and for TV-E c.1095delA, p.273; all these variations resulted in frame shift mutation. In order to substantiate these results in silico analysis was carried out; the structural superimposition of wild type and mutant WT1 structures showed that the mutated region exhibited a different confirmation with RMSD of 1.759Å. Therefore, these results conclusively explain the mutation in the WT1 gene that leads to structural changes contributing to glomerulosclerosis.

Le Page C, Köbel M, de Ladurantaye M, et al.
Specimen quality evaluation in Canadian biobanks participating in the COEUR repository.
Biopreserv Biobank. 2013; 11(2):83-93 [PubMed] Related Publications
Human biological specimens are important for translational research programs such as the Canadian Ovarian Experimental Unified Resource (COEUR) funded by the Terry Fox Research Institute. Sample quality is an important consideration, as it directly impacts the quality of ensuing research. The aim of the present study was to determine the quality of tissues collected from different sites contributing to the COEUR cohort. Samples from high-grade serous ovarian tumors (fresh frozen and corresponding paraffin-embedded tissues) were provided by nine participating Canadian biobanks. All samples were shipped to a central site using a Standard Operating Protocol (SOP). DNA and RNA extraction was conducted by the quality control division of the Canadian Tumor Repository Network (CTRNet). DNA quality was determined by ß-globin gene PCR amplification, and RNA quality by the RNA integrity number (RIN), as measured by the Agilent BioAnalyzer. DNA of acceptable quality had at least three bands of ß-globin amplified from DNA (n=115/135), and a RIN number ≥7 was considered very good for RNA (n=80/135). Sample preparation and storage time had little effect on RNA or DNA quality. Protein expression was assessed on tissue microarray by immunohistochemistry with antibodies against p53, WT1, E-cadherin, CK-7, and Ki67 from formalin fixed-paraffin embedded (FFPE) tissues. As seen with a nonhierarchical clustering statistical method, there was no significant difference in immunostaining of paraffin tissues among specimens from different biobanks. Interestingly, patients with worse outcome were highly positive for p53 and weak for WT1. In conclusion, while there was no common SOP for retrospectively collected material across Canadian biobanks, these results indicate that specimens collected at these multiple sites are of comparable quality, and can serve as an adequate resource to create a national cohort for the validation of molecular biomarkers in ovarian cancer.

Arnold MA, Schoenfield L, Limketkai BN, Arnold CA
Diagnostic pitfalls of differentiating desmoplastic small round cell tumor (DSRCT) from Wilms tumor (WT): overlapping morphologic and immunohistochemical features.
Am J Surg Pathol. 2014; 38(9):1220-6 [PubMed] Related Publications
Desmoplastic small round cell tumor (DSRCT) and blastemal-predominant Wilms tumor (WT) share overlapping histologic features, yet accurate distinction is critical because of differing prognosis and treatment. We encountered a neck mass in a young adult with a concomitant abdominal mass. The neck mass was initially concerning for DSRCT on the basis of the poorly differentiated morphology, desmoplastic stroma, and immunoreactivity for desmin and cytokeratin. However, focal triphasic elements and glomeruloid bodies were identified on deeper sections, WT1 immunoreactivity was seen with antibodies to both the amino-terminus and carboxy-terminus, and EWSR1-WT1 rearrangement studies were negative, supporting the ultimate diagnosis of WT. On the basis of the overlapping histologic features of DSRCT and blastemal-predominant WT, we undertook a comparison study of desmin and cytokeratin reactivity patterns. We found that, whereas desmin reactivity was more frequent in DSRCT (11 of 12) than in WT blastema (11 of 22, P=0.024), dot-like perinuclear reactivity was seen with equal frequency in desmin-reactive DSRCT (10 of 11) and WT blastema (10 of 11), illustrating an important diagnostic pitfall. Moreover, we demonstrate coexpression of desmin and cytokeratin in both DSRCT (9 of 12) and WT blastema (11 of 22). Importantly, although dot-like desmin reactivity and coexpression of desmin and cytokeratin are historically associated with DSRCT, we demonstrate that these features can be seen in either DSRCT or blastemal-predominant WT. In these challenging cases, detection of an EWSR1-WT1 rearrangement and selective WT1 carboxy-terminus immunoreactivity (characteristic of DSRCT) or dual immunoreactivity for the WT1 amino-terminus and carboxy-terminus (characteristic of WT) remain the most discriminating diagnostic tools.

Katuri V, Gerber S, Qiu X, et al.
WT1 regulates angiogenesis in Ewing Sarcoma.
Oncotarget. 2014; 5(9):2436-49 [PubMed] Free Access to Full Article Related Publications
Angiogenesis is required for tumor growth. WT1, a protein that affects both mRNA transcription and splicing, has recently been shown to regulate expression of vascular endothelial growth factor (VEGF), one of the major mediators of angiogenesis. In the present study, we tested the hypothesis that WT1 is a key regulator of tumor angiogenesis in Ewing sarcoma. We expressed exogenous WT1 in the WT1-null Ewing sarcoma cell line, SK-ES-1, and we suppressed WT1 expression using shRNA in the WT1-positive Ewing sarcoma cell line, MHH-ES. Suppression of WT1 in MHH-ES cells impairs angiogenesis, while expression of WT1 in SK-ES-1 cells causes increased angiogenesis. Different WT1 isoforms result in vessels with distinct morphologies, and this correlates with preferential upregulation of particular VEGF isoforms. WT1-expressing tumors show increased expression of pro-angiogenic molecules such as VEGF, MMP9, Ang-1, and Tie-2, supporting the hypothesis that WT1 is a global regulator of angiogenesis. We also demonstrate that WT1 regulates the expression of a panel of pro-angiogenic molecules in Ewing sarcoma cell lines. Finally, we found that WT1 expression is correlated with VEGF expression, MMP9 expression, and microvessel density in samples of primary Ewing sarcoma. Thus, our results demonstrate that WT1 expression directly regulates tumor angiogenesis by controlling the expression of a panel of pro-angiogenic genes.

Dong W, Zhang J, Shao N, et al.
Development and immunological evaluation of HLA-specific chronic myeloid leukemia polyepitope vaccine in Chinese population.
Vaccine. 2014; 32(28):3501-8 [PubMed] Related Publications
BACKGROUND: BCR/ABL and Wilms' tumor 1 (WT1) are an ideal tumor associated antigens which can be used to develop a potential chronic myeloid leukemia (CML) dentritic cell (DC) vaccine. Here, we constructed a novel polyepitope vaccine which used recombinant lentiviral vector carrying BCR/ABL and WT1 genes, and determined the immunological effects of this vaccine in vitro.
METHODS: The DC vaccine was constructed using lentiviral vector transduced DCs. T lymphocytes were stimulated with DC vaccine and then co-cultured in vitro with peripheral blood mononuclear cells (PBMCs) from CML or ALL patients, respectively. The cytotoxicity of proliferous cytotoxic T lymphocytes (CTLs) was determined by the LDH assay. The IFN-γ production of CTLs was detected using ELISPOT assay.
RESULTS: We constructed an lentiviral vector encoding 50 different epitopes from BCR/ABL and WT1 antigens, and transferred it into DCs to prepare the DC vaccine successfully. The in vivo stimulation of CTLs with this DC vaccine were proved to show strong cytotoxicity and produce high level of IFN-γ.
CONCLUSIONS: The novel recombinant lentiviral polyepitope DC vaccine is a promising candidate for clinical trials and may be an effective approach for CML immunotherapy.

Coosemans A, Vergote I, Van Gool SW
Wilms' tumor gene 1 immunotherapy in pelvic gynecological malignancies.
Expert Rev Clin Immunol. 2014; 10(6):705-11 [PubMed] Related Publications
Pelvic gynecological malignancies account for 6% of all cancers. In the relapsed state, classical treatments are limited. There is an urgent need for new and personalized treatment. Wilms' tumor gene 1 (WT1) is the most important tumor-associated antigen. Although highly present in gynecological tumors, active immunotherapy against it is still underexplored. This review gives an insight into the importance of WT1 in pelvic gynecological malignancies and the first taken steps into the world of WT1 immunotherapy.

Keating GL, Reid HM, Eivers SB, et al.
Transcriptional regulation of the human thromboxane A2 receptor gene by Wilms' tumor (WT)1 and hypermethylated in cancer (HIC) 1 in prostate and breast cancers.
Biochim Biophys Acta. 2014; 1839(6):476-92 [PubMed] Related Publications
The prostanoid thromboxane (TX) A(2) plays a central role in hemostasis and is increasingly implicated in neoplastic disease, including prostate and breast cancers. In humans, TXA(2) signals through the TPα and TPβ isoforms of the T prostanoid receptor, two structurally related receptors transcriptionally regulated by distinct promoters, Prm1 and Prm3, respectively, within the TP gene. Focusing on TPα, the current study investigated its expression and transcriptional regulation through Prm1 in prostate and breast cancers. Expression of TPα correlated with increasing prostate and breast tissue tumor grade while the TXA(2) mimetic U46619 promoted both proliferation and migration of the respective prostate (PC3) and breast (MCF-7 and MDA-MD-231) derived-carcinoma cell lines. Through 5' deletional and genetic reporter analyses, several functional upstream repressor regions (URRs) were identified within Prm1 in PC3, MCF-7 and MDA-MB-231 cells while site-directed mutagenesis identified the tumor suppressors Wilms' tumor (WT)1 and hypermethylated in cancer (HIC) 1 as the trans-acting factors regulating those repressor regions. Chromatin immunoprecipitation (ChIP) studies confirmed that WT1 binds in vivo to multiple GC-enriched WT1 cis-elements within the URRs of Prm1 in PC3, MCF-7 and MDA-MB-231 cells. Furthermore, ChIP analyses established that HIC1 binds in vivo to the HIC1((b))cis-element within Prm1 in PC3 and MCF-7 cells but not in the MDA-MB-231 carcinoma line. Collectively, these data establish that WT1 and HIC1, both tumor suppressors implicated in prostate and breast cancers, transcriptionally repress TPα expression and thereby provide a strong genetic basis for understanding the role of TXA2 in the progression of certain human cancers.

Reuter CW, Krauter J, Onono FO, et al.
Lack of noncanonical RAS mutations in cytogenetically normal acute myeloid leukemia.
Ann Hematol. 2014; 93(6):977-82 [PubMed] Related Publications
Transforming mutations in RAS genes are commonly found in human malignancies, including myeloid leukemias. To investigate the incidence, spectrum, and distribution of activating K- and N-RAS mutations in cytogenetically normal acute myeloid leukemia (CN-AML) patients, 204 CN-AML patients were screened. Activating K- and N-RAS mutations were detected in 3 of 204 (1.5 %) and 22 of 204 (10.8 %) CN-AML samples, respectively. RAS mutated patients presented with a lower percentage of bone marrow blasts (65 vs 80 %, P = 0.022). RAS mutations tended to occur with nucleophosmin-1 (NPM1) mutations (P = 0.079), and all three samples containing K-RAS mutations had concomitant NPM1 mutations. There was no significant overlap between K-RAS mutations and N-RAS, FLT3, CEBPA, IDH1/2, WT1 or MLL mutations. RAS mutation status did not impact relapse-free or overall survival of CN-AML patients. In contrast to reports of noncanonical RAS mutations in other cancers, including some leukemia subtypes, we only observed K- and N-RAS mutations in codons 12, 13, or 61 in CN-AML samples. Our findings suggest that while K-RAS mutations are infrequent in CN-AML, activating K-RAS mutations may cooperate with mutated NPM1 to induce leukemia.

Cagnetta A, Adamia S, Acharya C, et al.
Role of genotype-based approach in the clinical management of adult acute myeloid leukemia with normal cytogenetics.
Leuk Res. 2014; 38(6):649-59 [PubMed] Related Publications
Acute myeloid leukemia (AML) is the most common form of acute leukemia affecting adults. Although it is a complex disease driven by numerous genetic and epigenetic abnormalities, nearly 50% of patients exhibit a normal karyotype (CN-AML) with an intermediate cytogenetic risk. However, a widespread genomic analysis has recently shown the recurrence of genomic aberrations in this category (mutations of FLT3, CEBPA, NPM1, RUNX1, TET2, IDH1/2, DNMT3A, ASXL1, MLL and WT1) thus revealing its marked genomic heterogeneity. In this perspective, a global gene expression analysis of AML patients provides an independent prognostic marker to categorize each patient into clinic-pathologic subgroups based on its molecular genetic defects. Consistently such classification, taking into account the uniqueness of each AML patient, furnishes an individualized treatment approach leading a step closer to personalized medicine. Overall the genome-wide analysis of AML patients, by providing novel insights into biology of this tumor, furnishes accurate prognostic markers as well as useful tools for selecting the most appropriate treatment option. Moreover it provides novel therapeutic targets useful to enhance efficacy of the current anti-AML therapeutics. Here we describe the prognostic relevance of such new genetic data and discuss how this approach can be used to improve survival and treatment of AML patients.

Dubrovsky L, Pankov D, Brea EJ, et al.
A TCR-mimic antibody to WT1 bypasses tyrosine kinase inhibitor resistance in human BCR-ABL+ leukemias.
Blood. 2014; 123(21):3296-304 [PubMed] Article available free on PMC after 22/05/2015 Related Publications
Acute and chronic leukemias, including CD34(+) CML cells, demonstrate increased expression of the Wilms tumor gene 1 product (WT1), making WT1 an attractive therapeutic target. However, WT1 is a currently undruggable, intracellular protein. ESKM is a human IgG1 T-cell receptor mimic monoclonal antibody directed to a 9-amino acid sequence of WT1 in the context of cell surface HLA-A*02. ESKM was therapeutically effective, alone and in combination with tyrosine kinase inhibitors (TKIs), against Philadelphia chromosome-positive acute leukemia in murine models, including a leukemia with the most common, pan-TKI, gatekeeper resistance mutation, T315I. ESKM was superior to the first-generation TKI, imatinib. Combination therapy with ESKM and TKIs was superior to either drug alone, capable of curing mice. ESKM showed no toxicity to human HLA-A*02:01(+) stem cells under the conditions of this murine model. These features of ESKM make it a promising nontoxic therapeutic agent for sensitive and resistant Ph(+) leukemias.

Specht K, Sung YS, Zhang L, et al.
Distinct transcriptional signature and immunoprofile of CIC-DUX4 fusion-positive round cell tumors compared to EWSR1-rearranged Ewing sarcomas: further evidence toward distinct pathologic entities.
Genes Chromosomes Cancer. 2014; 53(7):622-33 [PubMed] Article available free on PMC after 22/05/2015 Related Publications
Round cell sarcomas harboring CIC-DUX4 fusions have recently been described as highly aggressive soft tissue tumors of children and young adults. Due to partial morphologic and immunohistochemical overlap with Ewing sarcoma (ES), CIC-DUX4-positive tumors have generally been classified as ES-like and managed similarly; however, a systematic comparison at the molecular and immunohistochemical levels between these two groups has not yet been conducted. Based on an initial observation that CIC-DUX4-positive tumors show nuclear immunoreactivity for WT1 and ETS transcription factors, FLI1 and ERG, we performed a detailed immunohistochemical and molecular analysis including these markers, to further investigate the relationship between CIC-DUX4 tumors and ES. The study group included 21 CIC-DUX4-positive sarcomas and 20 EWSR1-rearranged ES. Immunohistochemically, CIC-DUX4 sarcomas showed membranous CD99 positivity in 18 (86%) cases, but only 5 (24%) with a diffuse pattern, while WT1 and FLI1 were strongly positive in all cases. ERG was positive in 18% of cases. All ES expressed CD99 and FLI1, while ERG positivity was only seen in EWSR1-ERG fusion positive ES. WT1 was negative in all ES. Expression profiling validated by q-PCR revealed a distinct gene signature associated with CIC-DUX4 fusion, with upregulation of ETS transcription factors (ETV4, ETV1, and ETV5) and WT1, among top overexpressed genes compared to ES, other sarcomas and normal tissue. In conclusion, the distinct gene signature and immunoprofile of CIC-DUX4 sarcomas suggest a distinct pathogenesis from ES. The consistent WT1 expression may provide a useful clue in the diagnosis in the context of round cell sarcomas negative for EWSR1 rearrangement. © 2014 Wiley Periodicals, Inc.

Al-Hussain T, Ali A, Akhtar M
Wilms tumor: an update.
Adv Anat Pathol. 2014; 21(3):166-73 [PubMed] Related Publications
Wilms tumor (WT) is the most common neoplasm of the kidney in children. It is an embryologic tumor that histologically mimics renal embryogenesis and is composed of a variable mixture of stromal, blastemal, and epithelial elements. Nephrogenic rests, generally considered to be precursor lesions of the WT, are foci of the embryonic metanephric tissue that persist after the completion of renal embryogenesis. These are classified as perilobar and intralobar based on their location and maybe present as single or multiple foci. Intralobar and perilobar rests and the tumors arising from these rests differ morphologically and are characterized by 2 different sets of genetic abnormalities involving 2 adjacent foci, WT1 and WT2, on the short arm of chromosome 11. WTs arising in the intralobar rests tend to be stromal predominant and have a mutation or deletion of WT1. Germline mutation in WT1 may be associated with syndromic conditions such as WAGR and Denys-Drash syndromes. Perilobar rests and their corresponding tumors usually have loss of imprinting/loss of heterozygosity involving WT2, which contains several parentally imprinted genes. Loss of function of these genes, if present constitutionally, may be associated with Beckwith-Wiedemann syndrome or may result in isolated hypertrophy. Abnormalities in several other genes may also be seen in WT. These include WTX, (on chromosome X), CTNNB1 (chromosome 3), and TP53 (chromosome 17) among others. WT with loss of heterozygosity at 1p and 16q may have poor prognosis, requiring aggressive therapy. Treatment modalities for WT have evolved over many decades, primarily through the efforts of Dr J Bruce Beckwith at National WT study. This work is now being carried out by Children Oncology Group in North America and International Society of Pediatric Oncology in Europe. Although their therapeutic approaches are somewhat different, both have reported excellent results with equally high cure rates.

Christopeit M, Kröger N, Haferlach T, Bacher U
Relapse assessment following allogeneic SCT in patients with MDS and AML.
Ann Hematol. 2014; 93(7):1097-110 [PubMed] Related Publications
Options to pre-emptively treat impending relapse of myelodysplastic syndromes (MDS) and acute myeloid leukaemia (AML) after allogeneic haematopoietic stem cell transplantation (allo-SCT) continuously increase. In recent years, the spectrum of diagnostic methods and parameters to perform post-transplant monitoring in patients with AML and MDS has grown. Cytomorphology, histomorphology, and chimaerism analysis are the mainstay in any panel of post-transplant monitoring. This may be individually combined with multiparameter flow cytometry (MFC) for the detection of residual cells with a leukaemia phenotype and quantitative real-time polymerase chain reaction (RQ-PCR) to assess gene expression, e.g., of WT1 or the residual mutation load (e.g., in case of an NPM1 mutation). Data evaluating the aforementioned methods alone or in combination are discussed in this review with particular emphasis on data pointing towards their suitability to steer pre-emptive post-transplant interventions such as immunotherapy, chemotherapy or therapy with demethylating agents.

Lyu X, Xin Y, Mi R, et al.
Overexpression of Wilms tumor 1 gene as a negative prognostic indicator in acute myeloid leukemia.
PLoS One. 2014; 9(3):e92470 [PubMed] Article available free on PMC after 22/05/2015 Related Publications
Chromosomal aberrations are useful in assessing treatment options and clinical outcomes of acute myeloid leukemia (AML) patients. However, 40 ∼ 50% of the AML patients showed no chromosomal abnormalities, i.e., with normal cytogenetics aka the CN-AML patients. Testing of molecular aberrations such as FLT3 or NPM1 can help to define clinical outcomes in the CN-AML patients but with various successes. Goal of this study was to test the possibility of Wilms' tumor 1 (WT1) gene overexpression as an additional molecular biomarker. A total of 103 CN-AML patients, among which 28% had overexpressed WT1, were studied over a period of 38 months. Patient's response to induction chemotherapy as measured by the complete remission (CR) rate, disease-free survival (DFS) and overall survival (OS) were measured. Our data suggested that WT1 overexpression correlated negatively with the CR rate, DFS and OS. Consistent with previous reports, CN-AML patients can be divided into three different risk subgroups based on the status of known molecular abnormalities, i.e., the favorable (NPM1(mt)/no FLT3(ITD)), the unfavorable (FLT3(ITD)) and the intermediate risk subgroups. The WT1 overexpression significantly reduced the CR, DFS and OS in both the favorable and unfavorable groups. As the results, patients with normal WT1 gene expression in the favorable risk group showed the best clinical outcomes and all survived with complete remission and disease-free survival over the 37 month study period; in contrast, patients with WT1 overexpression in the unfavorable risk group displayed the worst clinical outcomes. WT1 overexpression by itself is an independent and negative indicator for predicting CR rate, DFS and OS of the CN-AML patients; moreover, it increases the statistical power of predicting the same clinical outcomes when it is combined with the NPM1(mt) or the FLT3(ITD) genotypes that are the good or poor prognostic markers of CN-AML.

Renneville A, Abdelali RB, Chevret S, et al.
Clinical impact of gene mutations and lesions detected by SNP-array karyotyping in acute myeloid leukemia patients in the context of gemtuzumab ozogamicin treatment: results of the ALFA-0701 trial.
Oncotarget. 2014; 5(4):916-32 [PubMed] Article available free on PMC after 22/05/2015 Related Publications
We recently showed that the addition of fractionated doses of gemtuzumab ozogamicin (GO) to standard chemotherapy improves clinical outcome of acute myeloid leukemia (AML) patients. In the present study, we performed mutational analysis of 11 genes (FLT3, NPM1, CEBPA, MLL, WT1, IDH1/2, RUNX1, ASXL1, TET2, DNMT3A), EVI1 overexpression screening, and 6.0 single-nucleotide polymorphism array (SNP-A) analysis in diagnostic samples of the 278 AML patients enrolled in the ALFA-0701 trial. In cytogenetically normal (CN) AML (n=146), 38% of the patients had at least 1 SNP-A lesion and 89% of the patients had at least 1 molecular alteration. In multivariate analysis, the independent predictors of higher cumulative incidence of relapse were unfavorable karyotype (P = 0.013) and randomization in the control arm (P = 0.007) in the whole cohort, and MLL partial tandem duplications (P = 0.014) and DNMT3A mutations (P = 0.010) in CN-AML. The independent predictors of shorter overall survival (OS) were unfavorable karyotype (P <0.001) and SNP-A lesion(s) (P = 0.001) in the whole cohort, and SNP-A lesion(s) (P = 0.006), DNMT3A mutations (P = 0.042) and randomization in the control arm (P = 0.043) in CN-AML. Interestingly, CN-AML patients benefited preferentially more from GO treatment as compared to AML patients with abnormal cytogenetics (hazard ratio for death, 0.52 versus 1.14; test for interaction, P = 0.04). Although the interaction test was not statistically significant, the OS benefit associated with GO treatment appeared also more pronounced in FLT3 internal tandem duplication positive than in negative patients.

Klijanienko J, Colin P, Couturier J, et al.
Fine-needle aspiration in desmoplastic small round cell tumor: a report of 10 new tumors in 8 patients with clinicopathological and molecular correlations with review of the literature.
Cancer Cytopathol. 2014; 122(5):386-93 [PubMed] Related Publications
BACKGROUND: Desmoplastic small round cell tumor (DSRCT) is a rare round cell sarcoma entity characterized by a specific t(11;22)(p13;q12) translocation, usually intra-abdominal localization and an aggressive clinical outcome. To date, only 35 DSRCT cases diagnosed by fine-needle aspiration have been described.
METHODS: This study reports the cytological diagnosis of DSRCT. Ten tumors from 8 patients were sampled for diagnosis and analyzed to search the characteristic translocation using fluorescence in situ hybridization or reverse transcription polymerase chain reaction methods.
RESULTS: Smears were always hypercellular and consisted of nonspecific round cell sarcoma. Nuclei were polymorphic round, kidney-, or heart-shaped. Nuclear molding was usually present. Paranuclear cytoplasmic densities were obvious and noted in 7 cases. Cytonuclear atypia, mitotic figures, numerous crushed nuclei, and apoptosis were frequently seen. Purple-stained stroma was present in 8 cases (ranging from few connective tissue fragments to large hyalinized deposits). Molecular studies based on cytological aspirates were performed in 8 patients. The presence of the fusion gene EWSR1-WT 1 transcript was identified in all, which confirmed the diagnosis of DSRCT.
CONCLUSIONS: Smears showing poorly differentiated round cells associated with cytoplasmic densities and connective stoma, in a specific clinical context, young adult age, intra-abdominal localization, suggestive immunocytochemical profile, and a unique cytogenetic abnormality are highly specific and allow an accurate diagnosis of DSRCT.

Busch M, Schwindt H, Brandt A, et al.
Classification of a frameshift/extended and a stop mutation in WT1 as gain-of-function mutations that activate cell cycle genes and promote Wilms tumour cell proliferation.
Hum Mol Genet. 2014; 23(15):3958-74 [PubMed] Article available free on PMC after 22/05/2015 Related Publications
The WT1 gene encodes a zinc finger transcription factor important for normal kidney development. WT1 is a suppressor for Wilms tumour development and an oncogene for diverse malignant tumours. We recently established cell lines from primary Wilms tumours with different WT1 mutations. To investigate the function of mutant WT1 proteins, we performed WT1 knockdown experiments in cell lines with a frameshift/extension (p.V432fsX87 = Wilms3) and a stop mutation (p.P362X = Wilms2) of WT1, followed by genome-wide gene expression analysis. We also expressed wild-type and mutant WT1 proteins in human mesenchymal stem cells and established gene expression profiles. A detailed analysis of gene expression data enabled us to classify the WT1 mutations as gain-of-function mutations. The mutant WT1(Wilms2) and WT1(Wilms3) proteins acquired an ability to modulate the expression of a highly significant number of genes from the G2/M phase of the cell cycle, and WT1 knockdown experiments showed that they are required for Wilms tumour cell proliferation. p53 negatively regulates the activity of a large number of these genes that are also part of a core proliferation cluster in diverse human cancers. Our data strongly suggest that mutant WT1 proteins facilitate expression of these cell cycle genes by antagonizing transcriptional repression mediated by p53. We show that mutant WT1 can physically interact with p53. Together the findings show for the first time that mutant WT1 proteins have a gain-of-function and act as oncogenes for Wilms tumour development by regulating Wilms tumour cell proliferation.

Rauscher J, Beschorner R, Gierke M, et al.
WT1 expression increases with malignancy and indicates unfavourable outcome in astrocytoma.
J Clin Pathol. 2014; 67(7):556-61 [PubMed] Related Publications
AIMS: The zinc finger transcription factor WT1 is expressed in astrocytic neoplasms and therefore is a potential target of immunotherapy in brain tumours. Our aim was to further elucidate the role of WT1 as a diagnostic and prognostic marker in neuropathology, particularly as to the differentiation of astrocytoma from oligodendroglioma as well as to the dependency of WT1 expression on clinically relevant parameters.
METHODS: 829 evaluable brain tumour samples were investigated by WT1 immunohistochemistry on full tissue routine slides, consisting of 442 glioblastomas, 303 astrocytomas, 41 oligodendrogliomas and 43 oligoastrocytomas. In addition public WT1 gene expression data of 351 gliomas were analysed.
RESULTS: Our data show that WT1 expression in diffuse astrocytic tumours increases with WHO tumour grade and is associated with older age, absence of IDH1 mutation but not related to O(6)- methyl guanine methyl transferase (MGMT) promoter methylation status. Univariable, but not multivariable survival analysis indicates that WT1 expression is associated with worse outcome in patients with diffuse astrocytoma but not glioblastoma.
CONCLUSIONS: The significant WT1 expression differences between diffuse astrocytomas, oligoastrocytomas and oligodendrogliomas, which are also present in the Repository for Molecular Brain Neoplasia Data, National Cancer Institute (REMBRANDT, 2005, http://rembrandt.nci.nih.gov) gene database set, provide a rationale for use of WT1 as part of a routine immunohistochemistry panel.

Nasomyon T, Samphao S, Sangkhathat S, et al.
Correlation of Wilms' tumor 1 isoforms with HER2 and ER-α and its oncogenic role in breast cancer.
Anticancer Res. 2014; 34(3):1333-42 [PubMed] Related Publications
BACKGROUND: Wilms' tumor 1 (WT1) gene has different functional properties depending on the isoform type. This gene correlates with cell proliferation in various types of cancer. Here, we investigated the expression of WT1 isoforms in breast cancer tissues, and focused on the oncogenic role through estrogen receptor-alpha (ER-α) and human epidermal growth factor receptor 2 (HER2).
MATERIALS AND METHODS: Expression of WT1(17AA+) and (17AA-) was investigated in adjacent normal breast and breast cancer using Reverse transcription-polymerase chain reaction and western blotting. The correlation of WT1 isoforms with HER2 and ER-α was examined using MCF-7 cells stably-overexpressing WT1s and siRNA against WT1 gene.
RESULTS: The expression of WT(17AA-) was significantly found in adjacent normal breast tissues. A mixture of WT1(17AA+) and WT1(17AA-) were highly expressed in breast carcinoma tissues. MCF-7 cells overexpressing WT1+/+ and WT1+/- represented strong expression of ER-α and HER2. Moreover, the silencing of WT1+/+ and WT1+/- resulted in a decrease of both ER-α and HER2 and led to a decrease of cell numbers.
CONCLUSION: Our results suggest that WT1(17AA+) was exhibited dominantly in breast carcinoma tissues. WT1+/+ and WT1+/- correlated with the high expression of ER-α and HER2, leading to cell proliferation and might be involved in cancer development and progression.

Rossi G, Minervini MM, Melillo L, et al.
Predictive role of minimal residual disease and log clearance in acute myeloid leukemia: a comparison between multiparameter flow cytometry and Wilm's tumor 1 levels.
Ann Hematol. 2014; 93(7):1149-57 [PubMed] Related Publications
In acute myeloid leukemia (AML), the detection of minimal residual disease (MRD) as well as the degree of log clearance similarly identifies patients with poor prognosis. No comparison was provided between the two approaches in order to identify the best one to monitor follow-up patients. In this study, MRD and clearance were assessed by both multiparameter flow cytometry (MFC) and WT1 expression at different time points on 45 AML patients achieving complete remission. Our results by WT1 expression showed that log clearance lower than 1.96 after induction predicted the recurrence better than MRD higher than 77.0 copies WT1/10(4) ABL. Conversely, on MFC, MRD higher than 0.2 % after consolidation was more predictive than log clearance below 2.64. At univariate and multivariate analysis, positive MRD values and log clearance below the optimal cutoffs were associated with a shorter disease-free survival (DFS). At the univariate analysis, positive MRD values were also associated with overall survival (OS). Therefore, post-induction log clearance by WT1 and post-consolidation MRD by MFC represented the most informative approaches to identify the relapse. At the optimal timing of assessment, positive MRD and log-clearance values lower than calculated thresholds similarly predicted an adverse prognosis in AML.

Further References

Van Driessche A, Berneman ZN, Van Tendeloo VF
Active specific immunotherapy targeting the Wilms' tumor protein 1 (WT1) for patients with hematological malignancies and solid tumors: lessons from early clinical trials.
Oncologist. 2012; 17(2):250-9 [PubMed] Free Access to Full Article Related Publications
There is a growing body of evidence that Wilms' tumor protein 1 (WT1) is a promising tumor antigen for the development of a novel class of universal cancer vaccines. Recently, in a National Cancer Institute prioritization project, WT1 was ranked first in a list of 75 cancer antigens. In this light, we exhaustively reviewed all published cancer vaccine trials reporting on WT1-targeted active specific immunotherapy in patients with hematological malignancies and solid tumors. In all clinical trials, vaccine-induced immunological responses could be detected. Importantly, objective clinical responses (including stable disease) were observed in 46% and 64% of evaluable vaccinated patients with solid tumors and hematological malignancies, respectively. Immunogenicity of WT1-based cancer vaccines was demonstrated by the detection of a specific immunological response in 35% and 68% of evaluable patients with solid tumors and hematological malignancies, respectively. In order to become part of the armamentarium of the modern oncologist, it will be important to design WT1-based immunotherapies applicable to a large patient population, to standardize vaccination protocols enabling systematic review, and to further optimize the immunostimulatory capacity of the vaccine components. Moreover, improved immunomonitoring tools that reveal clinically relevant T-cell responses will further shape the ideal WT1 immunotherapy strategy. In conclusion, the clinical results obtained so far in WT1-targeted cancer vaccine trials reveal an untapped potential for inducing cancer immunity with minimal side effects and hold promise for a new adjuvant treatment against residual disease and against cancer relapse.

Cheever MA, Allison JP, Ferris AS, et al.
The prioritization of cancer antigens: a national cancer institute pilot project for the acceleration of translational research.
Clin Cancer Res. 2009; 15(17):5323-37 [PubMed] Related Publications
The purpose of the National Cancer Institute pilot project to prioritize cancer antigens was to develop a well-vetted, priority-ranked list of cancer vaccine target antigens based on predefined and preweighted objective criteria. An additional aim was for the National Cancer Institute to test a new approach for prioritizing translational research opportunities based on an analytic hierarchy process for dealing with complex decisions. Antigen prioritization involved developing a list of "ideal" cancer antigen criteria/characteristics, assigning relative weights to those criteria using pairwise comparisons, selecting 75 representative antigens for comparison and ranking, assembling information on the predefined criteria for the selected antigens, and ranking the antigens based on the predefined, preweighted criteria. Using the pairwise approach, the result of criteria weighting, in descending order, was as follows: (a) therapeutic function, (b) immunogenicity, (c) role of the antigen in oncogenicity, (d) specificity, (e) expression level and percent of antigen-positive cells, (f) stem cell expression, (g) number of patients with antigen-positive cancers, (h) number of antigenic epitopes, and (i) cellular location of antigen expression. None of the 75 antigens had all of the characteristics of the ideal cancer antigen. However, 46 were immunogenic in clinical trials and 20 of them had suggestive clinical efficacy in the "therapeutic function" category. These findings reflect the current status of the cancer vaccine field, highlight the possibility that additional organized efforts and funding would accelerate the development of therapeutically effective cancer vaccines, and accentuate the need for prioritization.

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