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Genes Feb 2018Vascular endothelial growth factor A (VEGF-A) is a prominent pro-angiogenic and pro-permeability factor in the kidney. Alternative splicing of the terminal exon of... (Review)
Review
Vascular endothelial growth factor A (VEGF-A) is a prominent pro-angiogenic and pro-permeability factor in the kidney. Alternative splicing of the terminal exon of VEGF-A through the use of an alternative 3' splice site gives rise to a functionally different family of isoforms, termed VEGF-Ab, known to have anti-angiogenic and anti-permeability properties. Dysregulation of the VEGF-A/VEGF-Ab isoform balance has recently been reported in several kidney pathologies, including diabetic nephropathy (DN) and Denys-Drash syndrome. Using mouse models of kidney disease where the VEGF-A isoform balance is disrupted, several reports have shown that VEGF-Ab treatment/over-expression in the kidney is therapeutically beneficial. Furthermore, inhibition of certain splice factor kinases involved in the regulation of VEGF-A terminal exon splicing has provided some mechanistic insight into how VEGF-A splicing could be regulated in the kidney. This review highlights the importance of further investigation into the novel area of VEGF-A splicing in chronic kidney disease pathogenesis and how future studies may allow for the development of splicing-modifying therapeutic drugs.
PubMed: 29462869
DOI: 10.3390/genes9020098 -
American Journal of Physiology. Renal... Jul 2008The Wilms tumor suppressor gene WT1 is essential for early urogenital development: homozygous mutations in WT1 result in embryonic lethality due to a failure in the... (Review)
Review
The Wilms tumor suppressor gene WT1 is essential for early urogenital development: homozygous mutations in WT1 result in embryonic lethality due to a failure in the development of kidneys and gonads. In the adult kidney, WT1 expression is limited to the glomerular podocytes. Several human nephrotic diseases arise from mutations of the WT1 gene, including mutations that affect its zinc-fingers and alternative splicing of +/- KTS isoforms. These include WAGR (for Wilms tumor, aniridia, genitourinary anomalies, and mental retardation), and Frasier and Denys-Drash syndromes. Recent advances including the development of transgenic mouse models and conditionally immortalized podocyte cell lines are beginning to shed light on WT1's crucial role in podocyte function.
Topics: Animals; Cell Line; DNA; Denys-Drash Syndrome; Frasier Syndrome; Genes, Wilms Tumor; Humans; PAX2 Transcription Factor; Podocytes; RNA, Messenger; WT1 Proteins; Zinc Fingers
PubMed: 18385267
DOI: 10.1152/ajprenal.00597.2007 -
Asian Journal of Andrology 2014
Topics: Child; Denys-Drash Syndrome; Humans; Male; Mutation; WT1 Proteins
PubMed: 24625882
DOI: 10.4103/1008-682X.125396 -
Kidney International Sep 1997In patients with Denys-Drash syndrome, mutations of the Wilms' tumor suppressor gene are associated with nephroblastomas and developmental abnormalities of the genital...
In patients with Denys-Drash syndrome, mutations of the Wilms' tumor suppressor gene are associated with nephroblastomas and developmental abnormalities of the genital tract and renal glomerulus. Normally, the Wilms' tumor gene product (WT1) is expressed at high levels in visceral glomerular epithelial cells (VGEC) of the emerging fetal glomerulus. We demonstrate that WT1 could normally serve to suppress EGF receptor expression in VGEC, since immunoreactive EGF receptor is strikingly absent compared to epithelial cells of the emerging proximal and distal tubule, which lack WT1. When HEK293 cells were co-transfected with plasmids containing EGFR enhancer/promoter elements linked to a CAT reporter and plasmids containing WT1 cDNA, EGFR enhancer/promoter activity was suppressed by all wild-type WT1 isoforms, but not by deletion mutants of WT1 lacking normal zinc-finger or N-terminal domains. Surprisingly, plasmids expressing a Denys-Drash WT1 mutant (R394W) retained the ability to suppress EGFR promoter activity in this system. Furthermore, we found that immunoreactive EGFR was appropriately undetectable in glomeruli from a three-year-old girl with Denys-Drash syndrome and in sections of her Wilm's tumor. These data suggest that faulty suppression of EGFR cannot account for the abnormalities of glomerulogenesis seen in Denys-Drash patients.
Topics: Cell Line; Child, Preschool; ErbB Receptors; Female; Fetus; Genes, Wilms Tumor; Genitalia; Humans; Immunohistochemistry; Kidney; Kidney Glomerulus; Mutation; Reference Values; Syndrome; Transfection; Wilms Tumor
PubMed: 9291179
DOI: 10.1038/ki.1997.374 -
Journal of Pediatric Urology Oct 2019Given improvements in multimodality therapy, survival among children with Wilms tumor (WT) exceeds 90%. However, 15% of children with favorable histology and 50% of...
BACKGROUND
Given improvements in multimodality therapy, survival among children with Wilms tumor (WT) exceeds 90%. However, 15% of children with favorable histology and 50% of children with anaplastic WT experience recurrence or progression. Of patients with advanced disease, only 50% survive to adulthood. In adult malignancies (including renal tumors), patient survival has improved with the advent of immunotherapy. However, little is known about the immune microenvironment of WT, making the potential role of immunotherapy unclear.
OBJECTIVE
The objective of the study is to perform an exploratory, descriptive analysis of the immune milieu in WT.
STUDY DESIGN
Between 2016 and 2017, all pediatric patients with WT, some of whom received neoadjuvant chemotherapy, underwent ex vivo wedge biopsy at the time of nephrectomy. The fresh tumor tissue and peripheral blood samples were analyzed for infiltrating immune infiltrate and effector cells using flow cytometry. Immunohistochemistry was performed for CD4, CD8, and PD-L1 expression. Matched blood samples were obtained for each patient, and circulating immune cells were analyzed by flow cytometry.
RESULTS
A total of six patients were enrolled. One patient with neuroblastoma was excluded. The remaining five patients included the following: two with unilateral WT (resected before chemotherapy), two with bilateral WT (resected after neoadjuvant chemotherapy), and one with Denys-Drash syndrome, end-stage renal disease, and history of WT in the contralateral kidney. Immune analysis showed that WT were infiltrated by immune cells regardless of chemotherapy status. CD8 and CD4 T cells were present in the tumor tissue and exhibited an activated phenotype. Elevated levels of natural killer (NK) cells were observed in the tumors (Figure). Immune checkpoint PD-L1 was also found expressed in one of the tumors stained.
DISCUSSION
In this pilot study, it was found that WTs were infiltrated by immune cells (CD45+) both before and after chemotherapy. Elevated levels of NK cells infiltrating the tumor specimens, which were quantitatively increased compared with levels of NK cells circulating in the blood, were noted. T cells, particularly CD4+ and CD8+ T cells, were present in tumor specimens. Tumor-infiltrating CD4 and CD8 T cells displayed an activated phenotype as defined by increased expression of human leukocyte antigen-DR isotype (HLA-DR), programmed cell death protein 1 (PD1), and CD57. Together, these findings suggest that WT microenvironment is immune engaged and may be susceptible to immunotherapy similar to other malignancies.
CONCLUSIONS
These pilot data suggest an immune-engaged tumor microenvironment is present within WT. This implies that WT may be susceptible to immunotherapy similar to adult renal tumors and other adult malignancies. Follow-up studies are currently underway.
Topics: Antigens, CD; Biomarkers, Tumor; CD4-CD8 Ratio; Child, Preschool; Female; Follow-Up Studies; Humans; Immunity, Cellular; Immunotherapy; Kidney Neoplasms; Male; Pilot Projects; Prognosis; Retrospective Studies; T-Lymphocytes; Wilms Tumor
PubMed: 30981637
DOI: 10.1016/j.jpurol.2019.03.011 -
European Journal of Medical Genetics Nov 2020WT1 mutations cause a wide spectrum of renal and extrarenal manifestations concerning urogenital development and the development of tumors.
BACKGROUND
WT1 mutations cause a wide spectrum of renal and extrarenal manifestations concerning urogenital development and the development of tumors.
METHODS
We retrospectively collected the information on the genotype and phenotype of WT1 nephropathy from the multicenter registry since 2014 to 2019. All patients were stratified by renal function decline status or by sequence timing. Rapid progressive group was defined as rapidly developing into ERSD within 12 months since disease onset. Early sequencing group was defined as gene mutation identified before ERSD.
RESULTS
Thirty-three (3.5%) cases were identified with a WT1 mutation in patients with steroid resistant nephrotic syndrome (SRNS), proteinuria and chronic kidney disease (CKD) 3-5 stage of unknown origin. ESRD developed in twenty patients at a median age of 4.3 years old. Comparing study between the rapid progressive group (n = 8) and non-rapid progressive group (n = 25) showed no significant difference in age of onset, gender, syndrome phenotype, genotype and proteinuria except for initial estimated glomerular filtration rate (eGFR) (p = 0.021) or sequencing timing (p = 0.003). In multivariable logistic regression analysis, the delayed sequencing was associated with rapid renal function decline, even after adjusting for established clinical factors including syndromic phenotype, genotype, age onset and eGFR at initial stage (p = 0.019). The renal survival analysis did not show a significantly better outcome in early sequencing group than in delayed sequencing group (p > 0.05).
CONCLUSION
Screening for WT1 mutations should be performed in children with Wilms' tumor, proteinuria/SRNS or CKD. Early diagnosis of WT1 nephropathy through clinical and genetic findings is warranted.
Topics: Child, Preschool; Cohort Studies; Early Diagnosis; Female; Genetic Testing; Humans; Infant; Male; Multicenter Studies as Topic; Nephrotic Syndrome; Proteinuria; Renal Insufficiency, Chronic; WT1 Proteins; Wilms Tumor
PubMed: 32891756
DOI: 10.1016/j.ejmg.2020.104047 -
Nucleic Acids Research May 2018Wilms tumor protein (WT1) is a Cys2-His2 zinc-finger transcription factor vital for embryonic development of the genitourinary system. The protein contains a C-terminal...
Wilms tumor protein (WT1) is a Cys2-His2 zinc-finger transcription factor vital for embryonic development of the genitourinary system. The protein contains a C-terminal DNA binding domain with four tandem zinc-fingers (ZF1-4). An alternative splicing of Wt1 can add three additional amino acids-lysine (K), threonine (T) and serine (S)-between ZF3 and ZF4. In the -KTS isoform, ZF2-4 determine the sequence-specificity of DNA binding, whereas the function of ZF1 remains elusive. Three X-ray structures are described here for wild-type -KTS isoform ZF1-4 in complex with its cognate DNA sequence. We observed four unique ZF1 conformations. First, like ZF2-4, ZF1 can be positioned continuously in the DNA major groove forming a 'near-cognate' complex. Second, while ZF2-4 make base-specific interactions with one DNA molecule, ZF1 can interact with a second DNA molecule (or, presumably, two regions of the same DNA molecule). Third, ZF1 can intercalate at the joint of two tail-to-head DNA molecules. If such intercalation occurs on a continuous DNA molecule, it would kink the DNA at the ZF1 binding site. Fourth, two ZF1 units can dimerize. Furthermore, we examined a Denys-Drash syndrome-associated ZF1 mutation (methionine at position 342 is replaced by arginine). This mutation enhances WT1 affinity for a guanine base. X-ray crystallography of the mutant in complex with its preferred sequence revealed the interactions responsible for this affinity change. These results provide insight into the mechanisms of action of WT1, and clarify the fact that ZF1 plays a role in determining sequence specificity of this critical transcription factor.
Topics: Alternative Splicing; Amino Acid Sequence; Amino Acid Substitution; Base Sequence; Binding Sites; Crystallography, X-Ray; DNA; Denys-Drash Syndrome; Genes, Wilms Tumor; Humans; Models, Molecular; Mutation; Mutation, Missense; Nucleic Acid Conformation; Protein Conformation; Transcription Factors; WT1 Proteins; Zinc Fingers
PubMed: 29294058
DOI: 10.1093/nar/gkx1274 -
Genes & Development Feb 2003
Review
Topics: Cystic Fibrosis; Dementia; Denys-Drash Syndrome; Disease; Human Growth Hormone; Muscular Atrophy, Spinal; Mutation; Myotonic Dystrophy; Neoplasms; Parkinsonian Disorders; RNA Precursors; RNA Splicing; Retinitis Pigmentosa
PubMed: 12600935
DOI: 10.1101/gad.1048803 -
Pediatric Nephrology (Berlin, Germany) Apr 2022Wilms tumour (WT) survivors, especially patients with associated syndromes or genitourinary anomalies due to constitutional WT1 pathogenic variant, have increased risk...
BACKGROUND
Wilms tumour (WT) survivors, especially patients with associated syndromes or genitourinary anomalies due to constitutional WT1 pathogenic variant, have increased risk of kidney failure. We describe the long-term kidney function in children with WT and WT1 pathogenic variant to inform the surgical strategy and oncological management of such complex children.
METHODS
Retrospective analysis of patients with WT and constitutional WT1 pathogenic variant treated at a single centre between 1993 and 2016, reviewing genotype, phenotype, tumour histology, laterality, treatment, patient survival, and kidney outcome.
RESULTS
We identified 25 patients (60% male, median age at diagnosis 14 months, range 4-74 months) with WT1 deletion (4), missense (2), nonsense (8), frameshift (7), or splice site (4) pathogenic variant. Thirteen (52%) had bilateral disease, 3 (12%) had WT-aniridia, 1 had incomplete Denys-Drash syndrome, 11 (44%) had genitourinary malformation, and 10 (40%) had no phenotypic anomalies. Patient survival was 100% and 3 patients were in remission after relapse at median follow-up of 9 years. Seven patients (28%) commenced chronic dialysis of which 3 were after bilateral nephrectomies. The overall kidney survival for this cohort as mean time to start of dialysis was 13.38 years (95% CI: 10.3-16.4), where 7 patients experienced kidney failure at a median of 5.6 years. All of these 7 patients were subsequently transplanted. In addition, 2 patients have stage III and stage IV chronic kidney disease and 12 patients have albuminuria and/or treatment with ACE inhibitors. Four patients (3 frameshift; 1 WT1 deletion) had normal blood pressure and kidney function without proteinuria at follow-up from 1.5 to 12 years.
CONCLUSIONS
Despite the known high risk of kidney disease in patients with WT and constitutional WT1 pathogenic variant, nearly two-thirds of patients had sustained native kidney function, suggesting that nephron-sparing surgery (NSS) should be attempted when possible without compromising oncological risk. Larger international studies are needed for accurate assessment of WT1genotype-kidney function phenotype correlation.
Topics: Child; Child, Preschool; Female; Genes, Wilms Tumor; Humans; Infant; Kidney; Kidney Neoplasms; Male; Mutation; Neoplasm Recurrence, Local; Renal Dialysis; Renal Insufficiency; Retrospective Studies; WT1 Proteins; Wilms Tumor
PubMed: 34608521
DOI: 10.1007/s00467-021-05125-5 -
Cancer Aug 2020A primary objective of Children's Oncology Group study AREN0534 (Treatment for Patients With Multicentric or Bilaterally Predisposed, Unilateral Wilms Tumor) was to... (Clinical Trial)
Clinical Trial
BACKGROUND
A primary objective of Children's Oncology Group study AREN0534 (Treatment for Patients With Multicentric or Bilaterally Predisposed, Unilateral Wilms Tumor) was to facilitate partial nephrectomy in 25% of children with bilaterally predisposed unilateral tumors (Wilms tumor/aniridia/genitourinary anomalies/range of developmental delays [WAGR] syndrome; and multifocal and overgrowth syndromes). The purpose of this prospective study was to achieve excellent event-free survival (EFS) and overall survival (OS) while preserving renal tissue through preoperative chemotherapy, completing definitive surgery by 12 weeks from diagnosis, and modifying postoperative chemotherapy based on histologic response.
METHODS
The treating institution identified whether a predisposition syndrome existed. Patients underwent a central review of imaging studies through the biology and classification study AREN03B2 and then were eligible to enroll on AREN0534. Patients were treated with induction chemotherapy determined by localized or metastatic disease on imaging (and histology if a biopsy had been undertaken). Surgery was based on radiographic response at 6 or 12 weeks. Further chemotherapy was determined by histology. Patients who had stage III or IV disease with favorable histology received radiotherapy as well as those who had stage I through IV anaplasia.
RESULTS
In total, 34 patients were evaluable, including 13 males and 21 females with a mean age at diagnosis of 2.79 years (range, 0.49-8.78 years). The median follow-up was 4.49 years (range, 1.67-8.01 years). The underlying diagnosis included Beckwith-Wiedemann syndrome in 9 patients, hemihypertrophy in 9 patients, multicentric tumors in 10 patients, WAGR syndrome in 2 patients, a solitary kidney in 2 patients, Denys-Drash syndrome in 1 patient, and Simpson-Golabi-Behmel syndrome in 1 patient. The 4-year EFS and OS rates were 94% (95% CI, 85.2%-100%) and 100%, respectively. Two patients relapsed (1 tumor bed, 1 abdomen), and none had disease progression during induction. According to Response Evaluation Criteria in Solid Tumor 1.1 criteria, radiographic responses included a complete response in 2 patients, a partial response in 21 patients, stable disease in 11 patients, and progressive disease in 0 patients. Posttherapy histologic classification was low-risk in 13 patients (including the 2 complete responders), intermediate-risk in 15 patients, and high-risk in 6 patients (1 focal anaplasia and 5 blastemal subtype). Prenephrectomy chemotherapy facilitated renal preservation in 22 of 34 patients (65%).
CONCLUSIONS
A standardized approach of preoperative chemotherapy, surgical resection within 12 weeks, and histology-based postoperative chemotherapy results in excellent EFS, OS, and preservation of renal parenchyma.
Topics: Child; Child, Preschool; Combined Modality Therapy; Drug Therapy; Female; Humans; Infant; Kidney; Male; Neoplasm Metastasis; Nephrectomy; Progression-Free Survival; Treatment Outcome; WAGR Syndrome; Wilms Tumor
PubMed: 32459384
DOI: 10.1002/cncr.32958