Wilms Tumor 1 Research Articles

Restoration of WT1/miR-769-5p axis by HDAC1 inhibition promotes MMT reversal in mesenchymal-like mesothelial cells

Histone acetylation/deacetylation play an essential role in modifying chromatin structure and in regulating cell plasticity in eukaryotic cells. Therefore, histone deacetylase (HDAC) pharmacological inhibitors are promising tools in the therapy of fibrotic diseases and in cancer. Peritoneal fibrosis is a pathological process characterized by many cellular and molecular alterations, including the acquisition of invasive/pro-fibrotic abilities by mesothelial cells (MCs) through induction of mesothelial to mesenchymal transition (MMT). The aim of this study was to characterize the molecular mechanism of the antifibrotic role of HDAC1 inhibition. Specifically, treatment with MS-275, an HDAC1-3 inhibitor previously known to promote MMT reversal, induced the expression of several TGFBRI mRNA-targeting miRNAs. Among them, miR-769-5p ectopic expression was sufficient to promote MMT reversal and to limit MC migration and invasion, whereas miR-769-5p silencing further enhanced mesenchymal gene expression. These results were confirmed by HDAC1 genetic silencing. Interestingly, miR-769-5p silencing maintained mesenchymal features despite HDAC1 inhibition, thus indicating that it is necessary to drive MMT reversal induced by HDAC1 inhibition. Besides TGFBRI, miR-769-5p was demonstrated to target SMAD2/3 and PAI-1 expression directly. When analyzing molecular mechanisms underlying miR-769-5p expression, we found that the transcription factor Wilms’ tumor 1 (WT1), a master gene controlling MC development, binds to the miR-769-5p promoter favoring its expression. Interestingly, both WT1 expression and binding to miR-769-5p promoter were increased by HDAC1 inhibition and attenuated by TGFβ1 treatment. Finally, we explored the significance of these observations in the cell-to-cell communication: we evaluated the ability of miR-769-5p to be loaded into extracellular vesicles (EVs) and to promote MMT reversal in recipient mesenchymal-like MCs. Treatment of fibrotic MCs with EVs isolated from miR-769-5p over-expressing MCs promoted the down-regulation of specific mesenchymal targets and the reacquisition of an epithelial-like morphology. In conclusion, we highlighted an HDAC1-WT1-miR-769-5p axis potentially relevant for therapies aimed at counteracting organ fibrosis.

Downregulation of the Mutated WT1 Alleles in Malignant Hematopoietic Cells Via Nonsense-Mediated mRNA Decay Contradicts Their Prognostic Impact

Background The Wilms Tumor 1 (WT1) gene is highly expressed in almost all types of malignancies including acute myeloid leukemia (AML). It is also mutated in up to 20% of AML blasts in pediatric and adult patients. Both, the increased expression and also the presence of mutations are correlated negatively with chance of survival in different AML patient cohorts. We and others have previously showed devastating survival outcomes in children with AML blasts harboring WT1 mutations in combination FLT3-ITD and NUP98-NSD1 (Niktoreh et al., 2019). As WT1 can act as both, oncogene and tumor suppressor gene, this study was designed to analyze the WT1 genomic locus mutations in acute leukemia blasts. Methods and Results Screening for WT1 sequence alterations. Using the TruSight Myeloid Sequencing PanelTM (Illumina), we initially screened 35 leukemia and lymphoma cell lines for genomic alterations in 54 genes. This panel allowed us to detect even low variant-allele-frequency (VAF) alterations in the mutational hotspots of WT1, exons 7 and 9. In addition to a known WT1 mutation in CTS cells (AML M1), we discovered novel alterations in three other malignant cell lines. KASUMI-6 cells (AML M2) harbored the identical mutation as CTS cells, a 2-bp deletion in WT1 exon 7 leading to frameshift with a premature termination codon (c.1202_1203delGA, p.Arg401IlefsTer3). The U937 histiocytic lymphoma cells carried the known TP53 mutation and also an unknown heterozygous nonsense mutation in WT1 exon 7, changing the arginine 369 into a premature stop codon (c.1105C>T, p.Arg369Ter). Interestingly, MOLM-1 cells (CML in blast crisis) harbored a p.Arg462Gln alteration. Next, we performed Sanger sequencing for the complete coding region of WT1, including the upstream promoter as well as the 5'UTR and 3'UTR regions, all 10 exons and the adjacent 150 bp intronic sequences at the exon-intron boundaries. Sanger sequencing confirmed the mutations discovered via NGS and revealed single bp alterations in the WT1 promoter region of CTS cells and in the 5'UTR of K-562 cells. We also detected a recurring variation in intron 3 of WT1 (c.872+16G>A) in the cell lines K-562, NB-4, M07e and UOC-M1; the functional implications of the alterations are yet to be determined. Functional impact of WT1 mutations. To understand the potential impact of the WT1 sequence alterations, we studied the WT1 mRNA expression in these cells in the presence of cycloheximide (CHX), an inhibitor of the nonsense-mediated mRNA decay (NMD) machinery. As shown in figure 1A, U937 cells were used as negative control cells, as they are known to have no expression of the WT1 mRNA. Despite the presence of mutations in CTS, KASUMI-6 and MOLM-1 cells, all three cell lines expressed elevated levels of WT1, well within the range of 30 other malignant cell lines without any alterations/mutations in the WT1 locus (data not shown). To differentiate the WT1 expression between the mutated and the wildtype allele, we performed a fragment length analysis on a capillary electrophoresis system using the complimentary DNA of CHX-treated cell lines. For these analyses, we employed a multiplex PCR strategy using ABL1 as housekeeping gene and a primer pair binding in exons 4 and 10 of WT1. As delineated in figure 1B, the mutated alleles in CTS and KASUMI-6 cells, which are 2-bps shorter, could be easily separated from the wildtypes (data for KASUMI-6 not shown). Additionally, since our primer pair also amplified the alternatively spliced exon 5 and the alternative splice donor at the end of exon 9, leading to inclusion or exclusion of three amino acids (KTS), we were able to separately analyze the four major WT1 isoforms from both alleles. As shown in figure 1B, the expression levels of the WT1 mutated alleles of CHX-treated cells increased 2- to 3-fold compared to DMSO-treated cells in CTS and 3- to 4-fold in KASUMI-6 (data not shown). Conclusion Careful analyses of the WT1 genomic locus in 35 malignant hematological cell lines revealed previously unknown heterozygous loss-of-function WT1 mutations in KASUMI-6, MOLM-1 and U-937 cells. mRNA expression analysis demonstrated that these mutations are strongly regulated by NMD machinery, leading to (almost) complete downregulation of the mutated WT1 allele. These results strongly question any direct effect of WT1 mutations in the leukemic blasts and therefore cannot explain the role of mutations in WT1 as a prognostic factor in AML. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Prognostic Impact of WT1 Mutation on AML of Different Risk Groups Based on 2022 European Leukemianet (ELN) Risk Classification

Background The Wilms tumor 1 (WT1) gene, located on chromosome 11p13 exists in multiple isoforms. It has been implicated in the regulation of cell survival, proliferation and differentiation, and may function both as a tumor suppressor and an oncogene. Approximately 15% of acute myeloid leukemia (AML) patients carry WT1 mutations, and WT1 mutation have been shown to be independent predictor of worse clinical outcome in some but not all adult AML studies. Some studies suggested that NPM1-AML & AML with CEBPA double-mutation accompanied with WT1 mutation can alter their original favorable prognosis. Recently, a revised European LeukemiaNet (ELN) genetic risk classification has been published and the prognostic significance of WT1 mutation in three risk groups according to this 2022 ELIN risk classification is still unclear. Objective To investigate the prognostic significance of WT1 gene mutations in acute myeloid leukemia (AML) patients with different risk of the 2022-ELN risk classification. Methods 502 patients de novo AML diagnosed between March 2015 and July 2021 who underwent next-generation sequencing (NGS) tests and had MICM precise typing at the Peking University Institute of Hematology were enrolled in this study. The patients received chemotherapy ± hematopoietic stem cell transplantation (HSCT), and they were stratified into three groups according to the 2022 version of ELN-AML risk stratification. Results Among 502 patients, a total of 71 (14.1%) patients carried WT1 mutations, of which 57 patients had mutations at a single locus, 8 patients had mutations at double sites, 5 patients had co-mutations at 3 sites in the WT1 gene, and 1 patient had mutations at 4 sites. Comparing the incidence of AML-related mutations between the WT1 mutation group and the wild-type group, the results showed that the concomitant rate of NPM1 mutations was lower in the WT1 mutation group than in the WT1 wild-type group (14.1% vs 27.1%, p=0.028), and the concomitant rate of CEBPA-bZIP mutations was higher in the WT1 mutation group than in the WT1 wild-type group (29.6% vs 10.9%, p<0.001). The concomitant rate of CEBPA double mutation was also higher in the WT1 mutation group than in the WT1 wild-type group (29.6% vs 10.4%, p<0.001), and the concomitant rate of GATA2 mutation was higher in the WT1 mutation group than in the WT1 wild-type group (14.1% vs. 4.4%, p=0.004). In addition, the WT1 gene expression level (WT1/ABL1) was higher in the WT1 mutation group than in the WT1 wild group at diagnosis (22.0% vs 13.5%, p=0.004). All patients were further divided into 6 groups based on 2022 ELIN risk classification and whether they received HSCT. There were 158 (31.5%) patients in the low-risk chemotherapy group, 73 (14.5%) in the low-risk transplantation group, 72 (14.3%) in the intermediate-risk chemotherapy group, 58 (11.6%) in the intermediate-risk transplantation group, 78 (15.5%) in the high-risk chemotherapy group, and 63 (12.5%) in the high-risk transplantation group. Univariate and multivariate COX regression analyses were performed including WT1 mutation, FAB classification, age, sex, and karyotype stratification indicators. In 58 patients who were intermediate-risk and received HSCT, patients with WT1 mutation resulted in higher cumulative incidence of relapse(CIR) in compared with those without WT1 mutation (52.3% vs 33.5%, HR=9.28, p<0.001). In the remaining 5 groups of patients, WT1 mutation seemed have no significant effect on overall survival(OS), event-free survival (EFS), or CIR in patients (p-values were all less than 0.05). Conclusion Among intermediate-risk AML patients in the 2022 version of ELN stratification who received transplantation, the CIR after transplantation was higher in AML patients with WT1 mutation. It seemed that WT1 mutation was an independent risk factor for post-transplantation recurrence, and allogeneic HSCT cannot efficiently overcome the poor prognosis of WT1 mutation in the intermediate-risk group. Intermediate-risk AML with WT1 mutations still requires more active strategies to prevent relapse. Of course, the impact of WT1 mutation on prognosis needs to be further confirmed by expanding the sample size.

Abstract C049: WT1+ cancer-associated fibroblasts promote pancreatic cancer growth

Abstract Pancreatic ductal adenocarcinoma (PDA) is characterized by dense, fibro-inflammatory stroma that is established in early pathogenesis. Cancer-associated fibroblasts (CAFs) make up a significant proportion of the tumor microenvironment and represent a heterogeneous cell population that play both tumor-promoting and tumor-restricting roles. Despite their dramatic expansion in PDA pathogenesis, it is still unclear what cells in the normal pancreas give rise to these CAFs. Lineage-tracing experiments have previously identified pancreatic stellate cells, mesothelial, and tissue-resident fibroblasts as progenitors to subsets of CAFs. In this research, we firstly pulse-labeled cells expressing the mesothelial and fibroblast marker Wilms tumor 1 (WT1) in the normal pancreas of WT1CreERT;R26tdTomato mice and used an orthotopic model of PDA to trace their contribution to the PDA tumor microenvironment. We found WT1+ cells in the normal pancreas expanded to comprise a significant proportion of PDA CAFs according to immunofluorescence. Based upon single-cell RNA-sequencing (scRNA-seq), these WT1+ precursors represent an endogenous pancreatic fibroblast population similar to previously characterized universal adventitial fibroblasts (Pi16+, Dpp4+). To determine the role of WT1 in established PDA, we labeled WT1+ cells following orthotopic tumor implantation into WT1CreERT;R26tdTomato mice, and scRNA-seq analysis revealed that both inflammatory CAFs (iCAFs) and myofibroblastic CAFs (MyCAFs) express WT1. Notably, iCAFs had higher relative expression of WT1+. Additionally, we depleted WT1+ cells with diphtheria toxin from orthotopic tumors established in WT1CreERT;R26tdTomato/iDTR mice. We found depletion of WT1+ cells reduced orthotopic tumor growth, and depleted fibroblasts from the PDA tumor microenvironment. These findings implicate WT1 as a promising lineage tracing marker for a subset of pancreatic fibroblasts and demonstrates a pro-tumorigenic role of WT1+ fibroblasts in PDA. Citation Format: Allison Bischoff, Yaqing Zhang, Wei Yan, Kristee Brown, Wenting Du, Marina Pasca di Magliano. WT1+ cancer-associated fibroblasts promote pancreatic cancer growth [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C049.

Gilteritinib Maintenance Therapy Post-Allogenic Stem-Cell Transplantation Improves the Prognosis of Patients with FLT3-Mutated AML

Introduction FMS-like tyrosine kinase 3 (FLT3)-internal tandem duplication (ITD) and -tyrosine kinase domain (TKD) mutation were common mutations in acute myeloid leukemia (AML). FLT3-ITD mutation adversely affected the outcome of hematopoietic stem-cell transplantation (SCT). While sorafenib and midostaurin as maintenance therapy after SCT prolonged relapse-free and overall survival (OS), there are very few reports of post-transplant gilteritinib maintenance therapy outside of clinical trials. Hence, to explore the efficacy of the gilteritinib maintenance therapy post-SCT, we here report the prognostic impact of post-SCT gilteritinib maintenance in a clinical setting. Methods We retrospectively analyzed 25 FLT3-mutated relapsed or refractory AML patients who received allogeneic SCT at our center from January 1, 2011 to April 30, 2022. FLT3 mutation was analyzed by a commonly used polymerase chain reaction (PCR)-based assay. Measurable residual disease (MRD) was assessed by Wilms tumor 1 (WT1) mRNA expression in peripheral blood, and MRD positivity was defined as WT-1 >50 copies/μg in this study. Relapse was defined as an increase of 5% blasts or more. Non-relapse mortality (NRM) was defined as death without relapse. Leukemia-free survival (LFS) was defined as the time from transplantation to leukemia relapse or death from any cause, which comes first. OS was defined as the time from transplantation to death from any cause. Results The median age was 52 years. Twenty-two patients had ITD mutation and 5 had TKD mutation (2 had both ITD and TKD mutation). At the time of the transplant, 20 patients were in remission (6 were MRD-negative and 14 were MRD-positive) and five were in non-remission. All patients achieved hematologic complete remission (CR) after SCT and no patients relapsed within 30 days post-SCT. After hematological engraftment, 14 patients started to receive gilteritinib as maintenance therapy and 11 patients did not. Between the two groups, the patients' characteristics including disease status at transplant, SCT procedures, and donor sources were well balanced except for the administration of FLT3-inhibitor prior to SCT (100% in patients with gilteritinib maintenance and 45.5% in those without gilteritinib maintenance, p = 0.003). Eleven patients (78.6%) in the gilteritinib group and eight (72.7%) patients in the non-gilteritinib group had residual MRD in hematological CR or were non-CR prior to SCT. The median time from SCT to the initiation of gilteritinib was 36 days. The median dose at gilteritinib initiation was 40mg (range 20-120 mg). One patient developed grade 2 skin acute graft-versus-host disease (GVHD) after gilteritinib administration and 4/14 patients (28.6%) developed moderate-severe chronic GVHD (cGVHD, two developed pulmonary cGVHD, one eye and mouse, and one skin) with a median onset of 10.5 months (range 3.1-30.5 months), while only one patient temporary discontinued gilteritinib until the improvement of cGVHD. Late engraftment failure during gilteritinib maintenance was not observed. In terms of survival benefit, patients with gilteritinib maintenance showed significantly longer LFS and OS than those without gilteritinib (1-y LFS; 100% vs. 36.4%, 95% CI; 100-100% vs. 11.2-62.7%, p = 0.0028, Figure A, and 1-y OS; 100% vs. 45.5%, 95% CI; 100-100% vs. 16.7-70.7%, p = 0.0075, Figure B). The cumulative incidence of AML relapse at one-year in patients with gilteritinib maintenance group was significantly lower than those without (0% vs. 51.5%, 95% CI; 0-0% vs. 24.9-86.0%, p = 0.005). Especially, among patients with MRD positive or non-CR prior to SCT (n=19), patients who received gilteritinib maintenance showed a lower cumulative incidence of AML relapse at one-year than those without gilteritinib maintenance (0% vs. 68.8%, 95% CI; 0-0% vs. 35.9-95.2%, p = 0.0028, Figure C). Patients without MRD prior to SCT did not relapse with or without gilteritinib maintenance. These results suggest that gilteritinib maintenance therapy contributes to preventing post-transplant relapse in patients who remain MRD positive at the time of SCT. Conclusion Gilteritinib maintenance therapy post-SCT showed survival benefit in a clinical setting. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Early Results of MT-401 (Zedenoleucel) in Post-Transplant MRD+ aml Patients

Background: Measurable residual disease (MRD) testing has become more prevalent in AML. MRD positivity is associated with increased relapse risk and shorter survival in AML, and currently, there no approved therapies for these patients. Zedenoleucel (also known as MT-401) is a non-genetically modified allogeneic multi-tumor associated antigen (mTAA)-specific T cell therapy with selectivity to multiple tumor antigens, specifically preferentially expressed antigen in melanoma (PRAME), Wilms' tumor 1 (WT1), New York esophageal 1 (NY-ESO-1) and Survivin. An ongoing Phase 1 dose-escalation study (ADSPAM) conducted by Baylor College of Medicine (BCM) shows acceptable safety and tolerability at doses up to 200 x 106 cells administered post-HSCT in the adjuvant, as well as relapsed/refractory setting. There are promising preliminary clinical results with mTAA-specific T cell therapy targeting these same tumor antigens (Lulla et al., 2021). Objective: To determine whether MRD+ patients post-allogeneic transplant can be treated safely and effectively with multiTAA-specific T cells (MT-401/zedenoleucel) Methods: A multicenter Phase 2 study (ARTEMIS) evaluating the safety, tolerability and efficacy of zedenoleucel in patients with AML, including MRD+ patients, post-HSCT is ongoing. The study explores this therapy in patients with no active disease [in complete remission (CR) and MRD-] or in patients with active disease (frank relapse or MRD+). Patients may receive up to 3 consecutive infusions of zedenoleucel as a monotherapy (50-200 × 106 cells every 2 weeks) at weeks 0, 2 and 4 during the Intervention Period, and enter Follow-up at Week 8. Primary endpoints include various safety measurements. Efficacy evaluations occur at weeks 8, 12, 18, 24, 48 and yearly for 4 years using ELN recommendations for standard AML response criteria. MRD testing was done by flow cytometry or molecular testing (e.g. RT-PCR). Results: No concerning safety signals arose, including any dose-limiting toxicities in safety lead-in patients. The MRD+ patients had a variety of genetic mutations/abnormalities. One patient with NPM1 mutation converted from MRD+ to MRD- at week 8 evaluation. Another patient with RUNX1 genetic abnormality showed a decrease in MRD by PCR from a starting baseline of 0.8093% to resolution via peripheral blood at approximately 32 weeks post-treatment with MT-401. T cell composition of the product consisted of 71% CD4+ and 24% CD8+ T cells. T cell receptor (TCR) analysis identified 3,117 antigen-specific clones (881 Survivin, 783 NY-ESO-1, 750 PRAME, 709 WT1). Immune monitoring of this patient using biomarker analysis showed T cell specificity not only for the targeted antigens but also for non-targeted antigens over time, thereby demonstrating epitope spreading. Interestingly, the tumor antigen composition by RNASeq identified an antigen expression profile that changes over time and inversely correlates with the presence of antigen-specific T cells, demonstrating the interplay of tumor cell immunogenicity and antigen-specific T cells. Conclusions: The preliminary ARTEMIS results showed that administration of MT-401 converted MRD+ patients to MRD- indicating that early intervention with MT-401 administration at MRD+ stage in post-transplant AML can be beneficial.

Generation of antigen-specific T lymphocytes targeting Wilms tumor 1 using activated B cells

In order to develop a therapeutic target for T cells, it is necessary to amplify T cells and increase activity through antigen-presenting cells (APCs) expressing an intracellular cancer antigen. Although dendritic cells are frequently used as APCs, producing dendritic cells is costly and time-consuming. In addition, as dendritic cells are attached cells, they are not suitable for mass production for use as immune cell therapy. On the other hand, B cells are non-adherent floating cells, and thus can easily be cultured in suspension systems. As such, B cells can be considered as suitable substance cells for the development of immune cell therapeutics.B cells lack the antigen-presenting ability of dendritic cells. Therefore, to use B cells as APCs, we previously reported a technology that can be used which simply and effectively produces anti-viral T cells in vitro by activating B cells with α-galactosylceramide (α-GalCer). To apply this technology to anti-cancer treatment, Wilms tumor 1, the most representative cancer antigen expressed in various cancers, was selected. Wilms tumor 1 (WT1) was used to produce anti-cancer (anti-WT1) T cells using active B cells as APCs, and their respective activities were investigated.

Nanobody-based CAR T cells targeting intracellular tumor antigens

Chimeric antigen receptor (CAR) T-cell immunotherapy has become one of the research hotspots in the treatment of malignant tumors nowadays. However, the available tumor surface antigens are limited in number. Most tumor-associated antigens are intracellular molecules that can’t be targeted by conventional CAR T cells. As the major histocompatibility complex (MHC)/peptide complex is a presentation form of intracellular proteins on the surface of tumor cells, here, we chose the Glypican-3 (GPC3) oncoprotein and Wilms tumor 1 (WT1) oncoprotein as examples to explore whether nanobody (Nb)-based T cell receptor (TCR)-like CAR T cells could kill tumor cells by targeting the MHC/peptide complexes. Using the immune nanobody phage display library, we developed human leukocyte antigen (HLA)-A2/GPC3- and HLA-A2/WT1-specific nanobodies for the first time and then incorporated these nanobodies in two TCR-like CARs, targeting HLA-A2/GPC3 and HLA-A2/WT1 respectively. These TCR-like Nb CAR-redirected T cells could selectively recognize and lyse MHC/peptide complex-expressing tumor cells in vitro assays and subcutaneous mouse tumor models. This study offers a possible strategy for targeting intracellular antigens and widening the application of CAR T-cell therapy.

Overexpression of Plasmalemmal Vesicle-Associated Protein-1 Reflects Glomerular Endothelial Injury in Cases of Proliferative Glomerulonephritis with Monoclonal IgG Deposits

Proliferative glomerulonephritis with monoclonal IgG deposits (PGNMID) occasionally presents refractory nephrotic syndrome resulting in poor renal prognosis, but its etiology is not fully elucidated. Given that glomerular endothelial cell (GEC) stress or damage may lead to podocytopathy and subsequent proteinuria, as in thrombotic microangiopathy (TMA), diabetic kidney disease, and focal segmental glomerulosclerosis, we investigated the evidence of glomerular endothelial injury by evaluating the expression of plasmalemmal vesicle-associated protein-1 (PV-1), a component of caveolae in the cases of PGNMID. We measured the immunofluorescent PV-1 intensities of 23 PGNMID cases and compared with those of primary membranoproliferative glomerulonephritis (MPGN) (n= 5) and IgA nephropathy (IgAN) (n= 54) cases. PV-1 localization was evaluated with Caveolin-1, and CD31 staining, and the ultrastructural analysis was performed using a low-vacuum scanning electron microscope (LVSEM). To check the association of podocyte injury, we also conducted 8-oxoguanine and Wilms tumor 1 (WT1) double stain. We then evaluated PV-1 expression in other glomerulitis and glomerulopathy such as lupus nephritis and minimal change disease. The intensity of glomerular PV-1 expression in PGNMID is significantly higher than that in the other glomerular diseases, although the intensity is not associated with clinical outcomes such as urinary protein levels or renal prognosis. Immunostaining and LVSEM analysis revealed that glomerular PV-1 expression is localized in GECs in PGNMID. 8-oxoguanine accumulation was detected in WT1-positive podocytes but not in PV-1-expressing GECs, suggesting GEC-derived podocyte injury in PGNMID. PV-1 overexpression reflects glomerular endothelial injury, which could be associated with podocyte oxidative stress in PGNMID cases.

A case of Potter sequence with WT1 mutation.

Wilms tumor 1 (WT1) is the causative gene of Denys-Drash syndrome and Frasier syndrome, and in most cases, kidney failure develops after birth. We report an unusual case of Potter sequence due to fetal nephropathy and kidney failure with a WT1 mutation. The neonate was born at 37weeks of gestation, and had no distinctive facial appearance or anomalies of the extremities. The external genitalia were ambiguous. Presence of a penile-like structure or hypertrophic clitoris was noted, and the urethra opened at the base of the penis or clitoris. On ultrasonographic examination, the kidney sizes were small. No kidney cysts were noted, but the kidney parenchymal luminosity was increased. Although the neonate received mechanical ventilation because of severe retractive breathing after birth, he died of poor oxygenation due to air leak syndrome at 60h after birth. The congenital anomalies of the kidney and urinary tract (CAKUT) gene panel revealed a heterozygous missense mutation in WT1 [NM_024426.6:exon9:c.1400G > A, p.(Arg467Gln)]. In WT1, missense mutations are associated with earlier onset of nephropathy than nonsense or splicing mutations. However, severe cases of fetal onset and early neonatal death with WT1 mutations are rare, and only one severe case with the same missense mutation in WT1 has been reported. Therefore, WT1 mutation may be suspected in Potter sequence patients with external genital abnormalities, and the WT1 missense mutation in our case [NM_024426.6:exon9:c.1400G > A, p.(Arg467Gln)] may indicate a severe case with fetal onset of nephropathy and kidney failure.

The Detection of Immunity against WT1 and SMAD4P130L of EpCAM+ Cancer Cells in Malignant Pleural Effusion.

Malignant pleural effusion (MPE) provides a liquid tumor microenvironment model that includes cancer cells and immune cells. However, the characteristics of tumor antigen-specific CD8+ T cells have not been investigated in detail. Here, we analyzed MPE samples taken from a patient with pancreatic cancer who received a dendritic cell vaccine targeting Wilms’ Tumor 1 (WT1) antigen over the disease course (two points at MPE1st and 2nd, two months after MPE1st). Epithelial cell adhesion molecule (EpCAM)+ cancer cells (PD-L1− or T cell immunoglobulin mucin-3, TIM-3−), both PD-1 or TIM-3 positive CD8+ T cells, and CD14+CD68+CD163+TIM-3+ macrophages increased from the MPE1st to MPE2nd. The ratio of WT1-specific cytotoxic lymphocytes (WT1-CTLs) to MPE CD8+ T cells and IFN-γ secretion of WT1-CTLs were reduced with disease progression. Coincidentally, the fraction of central memory T (TCM) of WT1-CTLs was decreased. On the other hand, CD8+ T cells in response to SMAD4P130L, which is homogeneously expressed in EpCAM+ cancer cells, were detected using in vitro expansion with the HLA-A*11:01 restrictive SVCVNLYH neoantigen. Furthermore, the CD8+ T cell response to SMAD4P130L was diminished following remarkably decreased numbers of CD8+ TCM in MPE samples. In conclusion, CD8+ T cells responding to WT1 or SMAD4P130L neoantigen expressed in EpCAM+ pancreatic cancer cells were detected in MPE. A tumor antigen-specific immune response would provide novel insight into the MPE microenvironment.

Combined PD-L1 and TIM3 blockade improves expansion of fit human CD8+ antigen-specific T cells for adoptive immunotherapy

Antigen-specific Tcell expansion exvivo followed by adoptive transfer enables targeting of a multitude of microbial and cancer antigens. However, clinical-scale Tcell expansion from rare precursors requires repeated stimulation, which may lead toTcell dysfunction and limited therapeutic potential. We useda clinically compliant protocol to expand Epstein-Barr virus (EBV) and Wilms tumor 1 (WT1) antigen-specific CD8+ Tcells, and leveraged Tcell exhaustion-associated inhibitory receptor blockade to improve Tcell expansion. Several inhibitory receptors were expressed early by exvivo-expanded antigen-specific CD8+ Tcells, including PD-1 and TIM3, with co-expression matching evidence of Tcell dysfunction as the cultures progressed. Introduction of anti-PD-L1 and anti-TIM3 blockade in combination (but not individually) to the culture led to markedly improved antigen-specific Tcell expansion without inducing Tcell dysfunction. Single-cell RNA sequencing (RNA-seq) and Tcell receptor (TCR) repertoire profiling revealed that double blockade does not impart specific transcriptional programs in Tcells or alterations in TCR repertoires. However, combined blockade may affect gene expression in a minority of clonotypes in a donor-specific fashion. We conclude that antigen-specific CD8+ Tcell manufacturing can be improved by using TIM3 and PD-L1/PD-1 axis blockade in combination. This approach is readily applicable to several adoptive immunotherapy strategies.

Expression of Wilms' Tumor 1 Gene in Bone Marrow of Patients with Myelodysplastic Syndrome and Its Clinical Significance

To investigate the expression level and clinical significance of Wilms' tumor 1 (WT1) in bone marrow of patients with myelodysplastic syndromes (MDS). The clinical data of 147 MDS patients who accepted real-time quantitative polymerase chain reaction (RT-PCR) to detect the expression level of WT1 in bone marrow before treated in Nanfang Hospital, Southern Medical University from January 2017 to April 2021 were retrospectively analyzed. According to the expression level of WT1, the patients were divided into WT1+ group and WT1- group, their clinical characteristics and prognosis were analyzed. The positive rate of WT1 in 147 MDS patients was 82.3%. There were significant differences in bone marrow blast count, aberrant karyotypes, WHO 2016 classification, and IPSS-R stratification between WT1+ group and WT1- group (all P<0.05). Furthermore, the higher the malignant degree of MDS subtype and the risk stratification of IPSS-R, the higher expression level of WT1. Compared with WT1- group, there were no differences in overall survival (OS) time and the time of transformation to AML in WT1+ group (both P>0.05). In patients who did not accept transplantation, the median OS time of WT1+ patients was significantly shorter than that of WT1- patients (P=0.049). Besides, regarding WT1+ group, patients who underwent transplantation had longer OS time and lower mortality than those who received hypomethylating agents (P=0.002, P=0.005). WT1 expression level directly reflects the disease progression, and it is also associated with prognosis of MDS patients.

Clinical significance of the increased expression of the WT1 gene in peripheral blood of patients with acquired aplastic anemia.

To determine the significance of increased Wilms tumor 1 (WT1) gene expression in the peripheral blood of patients with acquired aplastic anemia (AA), we analyzed serial changes in WT1 mRNA copy number (WT1cn) in 63 patients with AA as well as in five patients with myelodysplastic syndromes (MDS) and seven patients with paroxysmal nocturnal hemoglobinuria (PNH). WT1cn was higher than the cut-off (≥50 copies/μg RNA) at the time of the first measurement in 41% of untreated (60-190 copies/μg RNA [median 130]) and 59% of treated (59-520 copies/μg RNA [median 150]) AA patients. Although WT1cns gradually increased in most AA patients during the 2-105 months follow-up period, they did not lead to clonal evolution except in three patients in whom the maximum change ratio of WT1cn (WT1cn-change max), defined as the ratio of WT1cn at the first examination to that of the maximum value, exceeded 20.0 and who developed MDS at 2, 46, and 105 months. Increased WT1 gene expression was enriched in granulocytes rather than in mononuclear cells in most WT1-positive AA patients and did not correlate with mutations of genes associated with myeloid malignancy. WT1cns were high at 690-5700 (median 2000) in MDS patients and remained high thereafter, while WT1cns in PNH patients (77-200; median 96) were similar to those in AA. Thus, moderate increases in WT1cns up to 600 are common in AA patients in stable remission. An increase in the WT1cn-change max over 20.0 may portend transformation from AA to MDS.

Frequency and clinical impact of WT1 mutations in the context of CEBPA-mutated acute myeloid leukemia

ABSTRACT Introduction Several studies have confirmed that mutations in the Wilms tumor 1 (WT1) gene occur in adult acute myeloid leukemia (AML). However, few data are available regarding the incidence of WT1 mutations in CEBPAmut AML and their impact. Methods We retrospectively analyzed the frequency and clinical impact of WT1 mutations in 220 newly diagnosed AML patients with CEBPA mutations(CEBPAmut). Chromosome karyotype analysis was performed by R or G banding method and further confirmed either by fluorescence in situ hybridization (FISH) and/or by multiple reverse transcription polymerase chain reaction (multiple RT–PCR). Mutations were detected with a panel of 112mutational genes using next-generation sequencing (NGS). Results Overall, 30 WT1 mutations were detected in 29 of the 220 CEBPAmut AML patients (13.18%) screened. These mutations clustered overwhelmingly in exon 7 (n=16). WT1 mutations were found to be significantly more frequent in AML patients with double-mutated CEBPA (CEBPAdm) than in AML patients with single-mutated CEBPA (17.36%vs. 8.08%, P = 0.043). Among WT1-mutated patients, the most common co-mutation was FLT3-ITD (n = 7, 24.14%), followed by NRAS (n = 5, 17.24%), CSF3R (n = 4, 13.79%), GATA2 (n = 4, 13.79%), and KIT (n = 4, 13.79%). The most frequent functional pathway was signaling pathways inas many as 62.07% of cases. Notably,the concomitant mutations in epigenetic regulatorswere inversely correlated with WT1 mutations(P = 0.003). CEBPAdm AML patients with WT1 mutations had inferior relapse-free survival, event-free survival and overall survival compared with patients CEBPAdm AML without WT1 mutations (P = 0.002, 0.004, and 0.010, respectively). Conclusion Our data showed that WT1 mutations are frequently identified in CEBPAmut AML, especially in CEBPAdm AML. CEBPAmut AML patients with WT1 mutations show distinct spectrum of comutations. In the context of CEBPAdm AML, WT1 mutations predict a poor prognosis.

Therapeutic potential of conditioned medium obtained from deferoxamine preconditioned umbilical cord mesenchymal stem cells on diabetic nephropathy model

BackgroundThe therapeutic potential of mesenchymal stem cells (MSCs)-derived conditioned media (CM) can be increased after preconditioning with various chemical agents. The aim of this study is comparative evaluation of effects of N-CM and DFS-CM which are collected from normal (N) and deferoxamine (DFS) preconditioned umbilical cord-derived MSCs on rat diabetic nephropathy (DN) model.MethodsAfter incubation of the MSCs in serum-free medium with/without 150 µM DFS for 48 h, the contents of N-CM and DFS-CM were analyzed by enzyme-linked immunosorbent assay. Diabetes (D) was induced by single dose of 55 mg/kg streptozotocin. Therapeutic effects of CMs were evaluated by biochemical, physical, histopathological and immunohistochemical analysis.ResultsThe concentrations of vascular endothelial growth factor alpha, nerve growth factor and glial-derived neurotrophic factor in DFS-CM increased, while one of brain-derived neurotrophic factor decreased in comparison with N-CM. The creatinine clearance rate increased significantly in both treatment groups, while the improvement in albumin/creatinine ratio and renal mass index values were only significant for D + DFS-CM group. Light and electron microscopic deteriorations and loss of podocytes-specific nephrin and Wilms tumor-1 (WT-1) expressions were significantly restored in both treatment groups. Tubular beclin-1 expression was significantly increased for DN group, but it decreased in both treatment groups. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive apoptotic cell death increased in the tubules of D group, while it was only significantly decreased for D + DFS-CM group.ConclusionsDFS-CM can be more effective in the treatment of DN by reducing podocyte damage and tubular apoptotic cell death and regulating autophagic activity with its more concentrated secretome content than N-CM.Graphical

Development and validation of a prognostic scoring model to risk stratify childhood acute myeloid leukaemia.

SummaryTo create a personal prognostic model and modify the risk stratification of paediatric acute myeloid leukaemia, we downloaded the clinical data of 597 patients from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database as a training set and included 189 patients from our centre as a validation set. In the training set, age at diagnosis, ‐7/del(7q) or ‐5/del(5q), core binding factor fusion genes, FMS‐like tyrosine kinase 3‐internal tandem duplication (FLT3‐ITD)/nucleophosmin 1 (NPM1) status, Wilms tumour 1 (WT1) mutation, biallelic CCAAT enhancer binding protein alpha (CEBPA) mutation were strongly correlated with overall survival and included to construct the model. The prognostic model demonstrated excellent discriminative ability with the Harrell's concordance index of 0.68, 3‐ and 5‐year area under the receiver operating characteristic curve of 0.71 and 0.72 respectively. The model was validated in the validation set and outperformed existing prognostic systems. Additionally, patients were stratified into three risk groups (low, intermediate and high risk) with significantly distinct prognosis, and the model successfully identified candidates for haematopoietic stem cell transplantation. The newly developed prognostic model showed robust ability and utility in survival prediction and risk stratification, which could be helpful in modifying treatment selection in clinical routine.

WT1 Inhibits Human Renal Carcinoma Cell Proliferation and Induces G2/M Arrest by Upregulating IL-24 Expression.

The transcription factor Wilms' tumor 1 (WT1) is involved in development, tissue homeostasis, and disease. However, the exact roles and the mechanisms of WT1 in renal carcinoma are not well understood. Therefore, in this study, we evaluated the ability of WT1 to block proliferation in renal carcinoma cells in vitro. Experimental analysis showed that WT1 overexpression inhibited the proliferation of renal carcinoma A498 cells and promoted arrest at the G2/M checkpoint. RNA-Seq identified differentially expressed genes, including IL-24, related to both the cell proliferation and the cell cycle. WT1 overexpression upregulated IL-24 expression, and IL-24 overexpression induced G2/M arrest. ChIP-Seq identified JUN as a direct target of WT1 in A498 cells, in which positive regulation was shown by RT-qPCR. It has been shown that the transcription factor JUN can regulate IL-24 expression, and therefore, we hypothesize that WT1 might regulate the IL-24 through JUN. Furthermore, analysis based on TCGA datasets showed that the expression of WT1-regulated genes, including TXNIP and GADD45A, was significantly correlated with the stage and histological grade of tumors, with high levels linked to favorable prognoses. Our results demonstrated that the overexpression of WT1 upregulates IL-24, leading to G2/M checkpoint arrest to reduce proliferation. These results indicate that regulation of IL-24 by WT1 inhibits proliferation and may represent a potential target for treating renal carcinoma.

Correlation of Wilms' Tumor 1 (WT1) with Oxidative Stress Markers and Expression of miR-361-5p; New Aspect of WT1 in Breast Cancer.

Breast carcinoma is a heterogeneous disease that affects millions of women worldwide. Wilms' tumor 1 (WT1) is an oncogene that promotes proliferation, metastasis and reduces apoptosis. MicroRNAs (miR) are short noncoding RNAs with a major role in cancer metastasis. In present study, we investigated the association of serum level of WT1 with oxidative stress and expression of miR-361-5p in breast cancer. Serum samples of 45 patients and of 45 healthy women analyzed for protein level of WT1, malondialdehyde (MDA), total oxidant status (TOS), and total antioxidant capacity (TAC). Serum and tissue expression of miR-361-5p in 45 tumor tissues and 45 paired non-tumor adjacent tissues and 45 serum samples of patients and healthy women analyzed by qRT-PCR. Protein levels of WT1 not significantly difference in serum of patients compared to healthy controls. Serum levels of MDA and TOS in patients were higher, but TAC level was lower than healthy controls (p < 0.001). There was a positive correlation between WT1 with MDA and TOS, and a negative correlation between WT1 with TAC in patients. miR-361-5p expression in tumor tissues and serum of patients was lower than non-tumor adjacent tissues and serum of healthy controls, respectively (p < 0.001). Moreover, there was a negative correlation between miR-361-5p and WT1 in patients. The positive correlation between WT1 with MDA and TOS and negative correlation between TAC and miR-361-5p suggests that this gene can play an important role in worse prognoses in breast cancer. Additionally, miR-361-5p may serve as an invasive biomarker for early detection of breast cancer.

Elucidation of HER2/neu and Wilms’ tumor 1 immunohistochemical expression in endometrial carcinomas regarding the diagnostic and prognostic significance

Objective To confirm HER2 neu and Wilms’ tumor 1 (WT1) immunohistochemical expression in endometrial cancer and illustrate its possible diagnostic and prognostic significance in various clinicopathological parameters that both physicians and pathologists may find therapeutically valuable. Materials and methods A total of 50 formalin-fixed and paraffin-embedded tissue specimens were acquired and prepared for this investigation from the archival pathology files of Al-Hussein and Al-Zahraa University Hospitals between 2017 and 2020, after obtaining the informed consent and approval of the local ethical committee. The patient’s medical records and histopathologic data such as tumor size, myometrial invasion depth, lymph node invasion, histologic type of tumor, clinical presentation, and International Federation of Gynecology and Obstetrics stage were assessed using hematoxylin-eosin for all sections that were re-evaluated by HER2/neu and WT1 antibodies immunohistochemically. Results Positive HER2/neu and WT1 expressions were frequently associated with a worsening condition in patients with endometrial carcinomas (ECs) with a higher grade, stage, and nonendometrioid carcinoma type, reflecting the prognostic relevance of HER2/neu and WT1 expressions, especially in aggressive EC forms. Follow-up and more genetic concordance between EC subtypes could improve the predictive value of HER2/neu and WT1 expression in EC. For advanced endometrial malignancies, tailored chemotherapy may be valuable. Conclusions HER2/neu-positive and WT1-positive immunohistochemical staining results are generally coupled to ECs in their advanced forms, which have a higher grade, stage, and nonendometrioid carcinoma type, reflecting their prognostic implications, especially in aggressive EC types. However, additional validation is required before enrolling this panel in clinical settings, which could improve the value of prediction of HER2/neu and WT1 immunohistochemical markers in ECs. Moreover, targeted chemotherapy for aggressive endometrial cancers can be beneficial.