WT1 Expression Levels Research Articles

Wilms\u2019 tumor gene 1 is an independent prognostic factor for pediatric acute myeloid leukemia following allogeneic hematopoietic stem cell transplantation

BackgroundSequential monitoring of Wilms’ tumor gene 1 (WT1) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) could predict relapse in adult acute myeloid leukemia (AML). However, the prognostic role of WT1 in pediatric AML after allo-HSCT is unclear. Thus, we determined to see whether sequential monitoring of WT1 after allo-HSCT could predict relapse in AML children.MethodsPediatric AML patients receiving allo-HSCT from January 21, 2012 to December 20, 2018 at the Peking University Institute of Hematology were included in this study. WT1 expression level was determined by TaqMan-based reverse transcription-polymerase chain reaction. WT1 sequential monitoring was performed 1, 2, 3, 4.5, 6, 9, and 12 months post-transplantation and at 6-month intervals thereafter. The primary end point was relapse. The secondary end points included disease-free survival (DFS), overall survival (OS), and non-relapse mortality (NRM). Kaplan–Meier analysis was used for DFS and OS estimates, while competing risk analysis was used for estimating relapse and NRM.ResultsOf the 151 consecutive patients included, the median age was 10 years (range, 1–17). The optimal cutoff value of WT1 within 1 year after allo-HSCT to predict relapse was 0.8% (80 WT1 copies/104 ABL copies), with a sensitivity of 60% and specificity of 79%. Compared with WT1 expression < 0.8%, WT1 expression ≥0.8% indicated significantly higher 5-year cumulative incidence of relapse (CIR, 35.1% vs. 11.3%; P = 0.001), lower 5-year disease-free survival (DFS, 60.4% vs. 80.8%; P = 0.009), and lower 5-year overall survival (OS, 64.9% vs. 81.6%; P = 0.038) rates. Multivariate analyses showed that WT1 was an independent risk factor for relapse (HR 2.89; 95% confidence interval (CI), 1.25–6.71; P = 0.014). Both the CIR (5-year CIR: 8.3% vs. 11.3%; P = 0.513) and DFS (5-year DFS: 91.7% vs. 80.8%; P = 0.208) were comparable between patients achieving minimal residual disease (MRD) negativity after preemptive interferon-α (IFN-α) treatment and those without MRD after allo-HSCT, which were better than those of MRD-positive patients without preemptive therapies.ConclusionsSequential monitoring of WT1 could predict relapse in pediatric AML after allo-HSCT. WT1-directed immunotherapy may have the potential to prevent relapse and improve survival.

Significance and Mechanisms Analyses of RB1 Mutation in Bladder Cancer Disease Progression and Drug Selection by Bioinformatics Analysis.

Bladder cancer is still a disease of significant morbidity and mortality. In bladder cancer, RB1 is one of the most common mutant genes. In this study, we explored the Genomics of Drug Sensitivity in Cancer (GDSC) database for drug sensitivity. The latest TCGA data were downloaded for analysis. To deal with functional enrichment analysis, GSEA, KEGG and GO were used. Prognostic analyses have been carried out using the GEPIA online tool. Results from the GDSC database showed that bladder cancer cells with RB1 mutation are more resistant to Dactolisib, MK-2206 and GNE-317. RB1 mutation was found in 25%bladder cancer patients. Patients with RB1 mutation often had lower RB1 mRNA expression level and higher histologic grade. In addition, we identified 999 differentially expressed genes in both groups. Functional enrichment analysis suggested that DEGs were primarily enriched in multiple metabolic progressions, cell proliferation and cancer related pathways. There were strong correlations between WT1, GPR37, CHRM2 and EZH2 expression levels and the prognosis. In all, the significance of RB1 mutation in disease progression and drug selection in bladder cancer was suggested by our results, and multiple genes and pathways related to such a program were identified.

Crucial role of BAALC-expressing leukemic precursors in origin and development of posttransplant relapses in patients with acute myeloid leukemias

The presented data are showing the crucial role and great prognostic significance of BAALC-expressing leukemic precursors in origin and development of posttransplant relapses (PTR) in acute myeloid leukemia patients with different cytological variants. For evidence simultaneous serial measurements of BAALC and WT1 transcript copy numbers by means of quantitative real time polymerase chain reaction were used at diagnosis, before conditioning regimen as well as at PTR in 50 patients treated with allogeneic hematopoietic stem cell transplantation (alloHSCT). Thirty-eight of them were adults and twelve pediatric patients aged 1-60 years (median – 25.8 years). It was shown, that BAALC gene overexpression to be presented in all studied cytological and being combined with increased level of WT1 expression at PTR in most of them. This combination was prognostically poor since it is largely associated with increased cumulative incidence of PTR (p&lt;0.0001), and shortened event free (p&lt;0.0001) and overall survival (p=0.002).

The Prognostic Significance of Wilms' Tumor Gene 1 in Adult AML with Different Risk Stratification Following Allo-HSCT

INTRODUCTION: Wilms' tumor gene 1 is a "pan-leukemic marker" for evaluating measurable residual disease (MRD) in leukemia. The prognostic value in prediction of relapse following chemotherapy or allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been recognized. However, there lack relevant guidelines for WT1 gene quantification as a MRD assessment for patients with acute myeloid leukemia (AML) undergoing allo-HSCT. The optimal monitoring time and threshold of WT1 expression level for MRD assessment following allo-HSCT are still unclear. METHODS: We retrospectively investigated the dynamic change of WT1 expression level in bone marrow in 151 adult patients with AML following allo-HSCT. All patients were divided into two subgroup including complete remission (CR) and non-remission (NR), which was based on the disease status before HSCT. WT1 expression levels were compared between two subgroups. Meanwhile, Receiver operating characteristic (ROC) curve analysis was performed on WT1 expression levels at different time points and the highest value of WT1 before relapse-related intervention to find the cutoff values for relapse prediction. Furthermore, the cutoffs were tested by cumulative incidence of relapse (CIR), overall survival (OS) and disease-free survival (DFS), which were analyzed through the Kaplan-Meier method. RESULTS: Compared with complete remission (CR) subgroup, non-remission (NR) subgroup has a trend of a higher expression baseline and a rapidly increasing from 2 to 3 months after allo-HSCT. ROC curve analysis results showed that 0.6% was the optimal cutoff value for relapse prediction at 3 months after allo-HSCT. The cutoff level 0.6% was effective in identifying patients in CR and NR group. Among the patients with CR status (n=131), patients with WT1≥0.6% had a significantly higher 5-year cumulative incidence of relapse (CIR, 27.3% vs. 6.0%; p=0.006), than patients with WT1&amp;lt;0.6%. Meanwhile, among the patients with NR status before allo-HSCT (n=20), patients with WT1≥0.6% had a significantly higher 5-year cumulative incidence of relapse (CIR, 75.7% vs. 40.0%; p=0.021), than patients with WT1&amp;lt;0.6%.Although 0.6% was effective in both group, there was no significant difference in OS between the patients with WT1≥0.6% and &amp;lt;0.6% in CR group (p&amp;gt;0.05). Moreover, ROC analysis was performed using the highest value of WT1 before relapse-related intervention, which showed that 2.25% was the upper threshold for predicting relapse after transplantation. The upper cutoff 2.25% was only effective in CR group. In CR group, patients with WT1≥2.25% had a significantly higher 5-year cumulative incidence of relapse (CIR, 100% vs. 7.1%; p&amp;lt;0.001), than patients with WT1&amp;lt;2.25%. In NR group, there was no significant difference in the 5-year CIR between patients with WT1≥2.25% and patients with WT1&amp;lt;2.25% (CIR, 75.0% vs. 53.8%; p=0.215). Results showed that the cutoff 0.6% was the optimal threshold for NR patients, while the cutoff 2.5% or 1.2% might be the optimal threshold for CR group in relapse prediction. Because the intervention guided by higher cutoff value would decrease the transplant-related mortality which might be caused by more aggressive relapse intervention in CR group. CONCLUSION: Our results suggest that the relapse predictive WT1 level is different in patients with different risk stratification before HSCT and the 3th months after allo-HSCT is the most meaningful time point for WT1-based MRD monitoring and relapse intervention. Different intervention thresholds should be used according to the pre-transplant disease status. Patients in NR before transplant should strictly use 0.6% as the threshold, while for patients in CR can be appropriately widened. Disclosures No relevant conflicts of interest to declare.

One-Step Duplex Droplet Digital PCR for WT1 Overexpression

With the improvement of treatment methods in acute hematology malignancies, the development of sensitive tools for minimal residual disease assessment has become a priority. The monitoring of WT1 expression level by real-time quantitative PCR has been a standard for minimal residual disease evaluation in acute myeloid leukemia and, since 2009, has been optimized through a European LeukemiaNet effort in an established protocol with well-defined clinical end points. Building on the work of the European LeukemiaNet, this article reports the development of a novel, one-step duplex WT1/ABL1 droplet digital assay for WT1 overexpression detection. This assay provides accurate data with high precision and linearity, even at low-template concentration, while retaining strong correlation with the standardized method and therefore maintaining the framework to analyze the results in the context of acute myeloid leukemia patients.

Crucial Role of BAALC-Expressing Progenitor Cells in Emergence and Development of Post-Transplantation Relapses in Patients with Acute Myeloid Leukemia

This article presents data demonstrating frequent BAALC hyperexpression, also in combination with WT1 hyperexpression, in children and adults with acute myeloid leukemia (AML). Treatment included allogeneic hematopoietic stem cell transplantation. The analysis of serial measurements of BAALC and WT1 expression level in 50 AML patients (37 adults and 13 children) showed that the increased BAALC expression is more common in patients with M1, M2, M4, and M5 FAB variants of AML with equal frequency in adults and children. Furthermore, the increased BAALC expression was rather common in combination with the increased WT1 expression, which predicted poorer prognosis. Since BAALC expression level in AML patients is closely related to AML-producing progenitor cells of leukemia hematopoiesis, a serial study of this phenomenon offers insights into the role of these cells in emergence and development of post-transplantation relapses, which is of both theoretical and practical importance.

DC Vaccination Induces Antigen Specific Immune Responses in AML Patients: A 1-Year Interim Assessment

Acute myeloid leukemia (AML) is a lethal hematological malignancy characterized by high rates of relapse (50%). Studies of immune responses in AML patients led to identification of two leukemia-associated antigens (Wilms' tumor protein 1 (WT1) and preferentially expressed antigen of melanoma (PRAME) for which cellular and humoral immune responses were detected. Based on expression profiles in AML and normal tissues, WT1 and PRAME were selected as target antigens for a DC vaccine, aiming to elicit adaptive and innate immune responses in AML patients. The primary objective of the trial (EudraCT No.: 2014-003520-44) is to evaluate safety and feasibility of active immunotherapy with antigen-loaded autologous DCs. The secondary objectives are to assess DC vaccination-induced T cell responses against WT1 and PRAME and to evaluate the clinical outcome over a period of 2 years or until disease progression/relapse. WT1-positive AML patients, with or without PRAME positivity were included, if they had a morphological remission with or without hematological recovery (CRi) after induction chemotherapy and were not eligible for allogeneic hematopoietic stem cell transplantation. DCs were administered intradermally (2.5x106 WT1 plus 2.5x106 PRAME DCs) on a weekly basis for 4 consecutive weeks, followed by administration on week 6 and then every 4 weeks until 2 years, tumor progression or patient withdrawal. This report focusses on the immune-monitoring data collected during the first year of treatment. Multiple parameters were evaluated, including WT1- and PRAME specific T cell responses in peripheral blood (IFN-g ELISPOT), the recurrence of WT1- and/or PRAME-positive AML blasts in bone marrow (qRT-PCR) and peripheral blood (flow cytometry), and occurrence of AML-specific mutations in bone marrow (NGS). DCs were assessed for expression of WT1 and PRAME and costimulatory molecules by flow cytometry, while secretion of IL10 and IL12 was evaluated by double-color ELISPOT. Twenty CR/CRi AML patients were vaccinated, and vaccination was well tolerated, and no signs of autoimmunity were observed. 12/20 patients remained stable throughout the first year of treatment, while 8/20 relapsed. 2/8 relapsed patients died due to progression of disease during the first year. In patients in stable remission, 7/12 patients had no detectable IFN-γ ELISPOT response in peripheral blood, 3/12 mounted a response and 2/12 were not evaluable due to high background production of IFN-γ. Positive IFN-γ ELISPOT responses were observed within 1-30 weeks of treatment and associated with a decrease over time in levels of WT1 (3/3) and/or PRAME mRNA (1/3) expression. Except for 2 patients who remained MRD-negative throughout the first year of treatment, ELISPOT-negative patients in remission (5/7) exhibited low, relatively stable levels of target antigens. Stable remissions were associated with one (3/12) or no (8/12) AML-related mutations while one patient was not evaluable. AML relapses were observed within 50 days in 4 patients, within 51-100 days in 1 patient, and after more than 150 days in 3 patients. Overall, 6/8 relapsing patients exhibited positive IFN-γ ELISPOT responses, while 2 patients relapsing in &lt;50 days failed to respond and one patient relapsing on day 77 exhibited an IFN-γ response at baseline. In all other relapsing patients, IFN-γ ELISPOT responses were detected within 6-30 weeks after vaccination, in association with rapid and progressive increases in levels of WT1 and/or PRAME. AML-related gene mutations were detected in 6/8 relapses, while one patient was not evaluable, and one had no mutation; In 4 of the relapsing patients, 3 to 6 mutations were detected, while in 2/8 a single mutation was observed. In conclusion, IFN-γ responses to WT1 and/or PRAME were detected in peripheral blood of 75% (6/8) of relapsing patients, but only 25% (3/12) of the patients in remission. It is tempting to speculate that detection of IFN-γ response in peripheral blood is linked to the concomitant presence of AML blasts in the periphery of relapsing patients. Stable or decreasing levels of WT1 and/or PRAME mRNA in bone marrow of most patients in remission is compatible with the hypothesis that a local response against AML antigens may be ongoing, despite a negative IFN-γ response in peripheral blood. Monitoring of the patients currently in remission may shed some light on the role of DC vaccination on the prevention of AML recurrence. Disclosures Eckl: Medigene Immunotherapies GmbH: Employment. Raffegerst:Medigene Immunotherapies GmbH: Employment. Schnorfeil:Medigene Immunotherapies GmbH: Employment. Prinz-Schulz:Medigene Immunotherapies GmbH: Employment. Fingerhut:Medigene Immunotherapies GmbH: Employment. Bigalke:BioNTech Innovative Manufacturing Services GmbH: Employment. Pinkernell:Medigene AG: Employment. Schendel:Medigene AG: Employment, Equity Ownership, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents &amp; Royalties. Tafuri:Medigene Immunotherapies GmbH: Employment.

Expression Pattern and Prognostic Significance of EVI1 Gene in Adult Acute Myeloid Leukemia Patients with Normal Karyotype.

According to current criteria, patients with acute myeloid leukemia with normal karyotype (AML-NK) are classified as intermediate risk patients. There is a constant need for additional molecular markers that will help in substratification into more precise prognostic groups. One of the potential new markers is Ecotropic viral integration 1 site (EVI1) transcriptional factor, whose expression is dissregulated in abnormal hematopoietic process. The purpose of this study was to examine EVI1 gene expression in 104 adult AML-NK patients and on 10 healthy bone marrow donors using real-time polymerase chain reaction method, and to evaluate association between EVI1 expression level and other molecular and clinical features, and to examine its potential influence on the prognosis of the disease. Overexpression of EVI1 gene (EVI1 + status) was present in 17% of patients. Increased EVI1 expression was predominantly found in patients with lower WBC count (P = 0.003) and lower bone marrow blast percentage (P = 0.005). EVI1 + patients had lower WT1 expression level (P = 0.041), and were negative for FLT3-ITD and NPM1 mutations (P = 0.036 and P = 0.003). Patients with EVI1 + status had higher complete remission rate (P = 0.047), but EVI1 expression didn't influence overall and disease free survival. EVI1 expression status alone, cannot be used as a new marker for more precise substratification of AML-NK patients. Further investigations conducted on larger number of patients may indicate how EVI1 expression could influence the prognosis and outcome of AML-NK patients, by itself, or in the context of other molecular and clinical parameters.

Significance of WT1 gene detection in the prognosis of acute myeloid leukemia patients with normal karyotype after hematopoietic stem cell transplantation

Objective To investigate the monitoring significance of WT1 gene level in the prognosis of acute myeloid leukemia (AML) patients with normal karyotype after hematopoietic stem cell transplantation (HSCT). Methods The clinical data of 115 AML patients with normal karyotype who were treated with HSCT from July 2009 to March 2017 in the First Affiliated Hospital of Soochow University were retrospectively analyzed. The dynamic detection of bone marrow WT1 gene was carried out by using reverse transcription- polymerase chain reaction (RT-PCR). According to the relative expression level median of WT1 gene before transplantation, the whole patients were divided into the two groups (< median group and ≥ median group) for survival analysis. Results There were 52 males and 63 females in 115 patients. The average age was (39±10) years old. The median white blood cell count at initial diagnosis was 20.45×109/L [(0.5-355.9)×109/L], the ratio of blast cells in the bone marrow was 0.60±0.28, and the relative expression level median of WT1 gene was 87×104, while the median time of the follow-up was 24 (3-79) months. Among 115 patients, 19 cases relapsed. Remission group (96 cases) and relapse group (19 cases) were followed up. The WT1 gene level was monitored by using bone marrow puncture in 1 month, 3 months, 6 months, 12 months after transplantation. It was found that the WT1 gene relative expression level of relapse group was higher than that of remission group, and the differences between the two groups at 6 month-point [remission group (187±50)×104, relapse group (871±211)×104, t= 2.519, P= 0.014] and 12 month-point [remission group (51±9)×104, relapse group (1 797±312)×104, t= 4.000, P < 0.05] were statistically different. The overall survival (OS) rate of 2-year, progression-free survival rate in WT1 gene relative expression level < 87×104 group were higher than those in WT1 gene relative expression level ≥ 87×104 group, the relapse rate in WT1 gene relative expression level < 87×104 group was lower than that in WT1 gene relative expression level ≥ 87×104 group, and the differences were statistically different (all P < 0.05). Multivariate analysis showed that the level of WT1 gene at 12 months after transplantation was an independent factor affecting OS (HR = 4.12, P = 0.046) and PFS (HR = 5.95, P = 0.001). There were 19 cases of recurrence (16.5%), with a median relapsed time of 11 (1-60) months. When WT1 gene relative expression level was significantly increased in 19 patients, firstly immunosuppressive agents were reduced, of which 6 patients were not influenced by this intervention; in other 13 cases, only 5 cases were influenced by intervention. Conclusions For CN-AML patients, the expression level of WT1 gene before transplantation has a negative correlation with the prognosis. The expression level of WT1 gene at 12 months after transplantation is an independent factor for affecting the survival. The relapsed patients have a higher WT1 expression level, and clinical interventions for relapsed patients have a favorable effect. Key words: Gene, WT1; Hematopoietic stem cell transplantation; Leukemia, myeloid, acute; Prognosis

Abstract IA17: Utilizing synthetic biology and high-dimensional probing to address therapeutic obstacles and empower engineered T cells with the capacity to eradicate tumors

Abstract We have been exploring in preclinical models and clinical trials methods to reproducibly provide therapeutic T cell responses by transfer of genetically engineered T cells. Our largest clinical experience is in treating human Acute Myelogenous Leukemia (AML). After identifying that WT1, a gene associated with promoting leukemic transformation, is over-expressed in human leukemic stem cells, and demonstrating in a clinical trial that in vitro expanded WT1-specific CD8 T cell clones can be safely transferred, exhibit anti-leukemic activity, and provide therapeutic benefit to AML patients, we extensively screened normal human repertoires and isolated a high affinity TCR specific for WT1 for genetically engineering CD8 T cells to reproducibly create cells with high avidity for leukemic cells. We have initially pursued this strategy in a 2 Arm trial for leukemia patients either at high risk of relapse (Arm 1) after hematopoietic cell transplant (HCT) or who have already relapsed after HCT (Arm 2). The prophylactic arm is now completed, with very encouraging results- all patients treated with engineered T cells remain alive and relapse free at a median of 38 months, compared to a relapse rate of ~50% in a concurrent matched cohort. Results in relapsed patients (Arm 2) have been less effective, and we have used high-dimensional analyses including single cell RNAseq both to elucidate the reasons for failure to eradicate the leukemia and to design strategies to overcome these obstacles. Our results have identified several mechanisms by which the leukemia escapes, and we have been testing approaches that employ further genetic modification of the T cells to enhance efficacy. The predominant reason for leukemia progression despite targeted therapy with T cells is the inability of the T cells to persist and maintain function in the context of encountering a rapidly proliferating myeloid leukemia. This reflects both engagement of pathways inhibitory to T cells by the leukemic cells, and apoptosis of the T cells from repetitive stimulation. We are addressing this issue by creating immuno-modulatory fusion proteins (IFPs) that have the ectodomain of an inhibitory or death receptor fused to a survival costimulatory domain. Results with two such IFPs will be discussed, a CD200R/CD28 fusion that binds the inhibitory ligand CD200 commonly expressed on leukemic cells but provides a CD28 costimulatory signal and a Fas/4-1BB fusion that binds FasL but rather than induce death promotes proliferation and survival. A more uncommon reason explaining progression is loss of expression of the WT1 epitope being targeted. This has occurred in 2 patients, but for distinct reasons. In one patient this reflected loss of a component of the immunoproteasome, and we have now isolated a TCR that recognizes an epitope not dependent on the immunoproteasome. In a second patient the level of WT1 expression declined- interestingly, this patient was treated with Vidaza, which can increase expression of WT1, and post-Vidaza the transferred T cells persisting in the patient’s bone marrow recognized and responded in vivo to the relapsing leukemia. The approaches and technologies we are developing and testing in leukemia are also applicable to solid tumors, and preclinical studies in pancreatic and ovarian cancers will be discussed. Citation Format: Kristin G. Anderson, Dan Egan, Sunil R. Hingorani, Shannon K. Oda, Kelly Paulson, Rachel Perret, Leah Schmidt, Thomas Schmitt, Ingunn Stromnes, Aude Chapuis, Philip D. Greenberg. Utilizing synthetic biology and high-dimensional probing to address therapeutic obstacles and empower engineered T cells with the capacity to eradicate tumors [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr IA17.

Aspirin attenuates podocyte injury in diabetic rats through overriding cyclooxygenase-2-mediated dysregulation of LDL receptor pathway.

This study aimed to investigate the effects of aspirin on podocyte injury and its underlying mechanisms in diabetic nephropathy (DN). Eight-week-old male Sprague-Dawley rats were divided into three groups: non-diabetic rats (Control), streptozotocin-induced diabetic rats (DM), and diabetic rats treated with aspirin (DM + Aspirin) for 12 weeks. Intracellular lipid accumulation was evaluated by Oil Red O staining and quantitative free cholesterol assays. Podocyte injury and the levels of COX-2, inflammatory cytokines, and low-density lipoprotein receptor (LDLr) pathway-related proteins were evaluated by electron microscopy, immunohistochemical staining, and Western blotting, respectively. Lipid levels and urinary albumin-creatinine ratios were higher in the DM rats than in the Control rats. Periodic acid-Schiff staining showed glomerular hypertrophy and mild mesangial area widening in the DM rats. Electron microscopy showed that the podocyte foot processes were significantly flattened or absent in the DM rats. The protein expression levels of WT-1 and nephrin in the podocytes of DM rats were reduced. Interestingly, lipid accumulation in the kidneys of DM rats was significantly increased due to increased protein expression levels of LDLr, sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP), SREBP-2, cyclooxygenase-2 (COX-2), and inflammatory cytokines. Confocal immunofluorescent staining showed that COX-2 and WT-1 were co-expressed. Furthermore, COX-2 protein expression levels were positively correlated with LDLr protein expression levels. However, when COX-2 expression was inhibited by aspirin, these changes in the DM rats were significantly attenuated. Aspirin attenuates podocyte injury in DN, which may be through COX-2-mediated dysregulation of LDLr pathway.

Wilms’ tumor 1 mRNA expression: a good tool for differentiating between myelodysplastic syndrome and aplastic anemia in children?

ABSTRACTObjectives: To evaluate the value of Wilms’ tumor 1 mRNA (WT1) expression in the differential diagnosis of childhood myelodysplastic syndrome (MDS) and aplastic anemia (AA).Methods: This study compared WT1 expression levels in children of MDS and AA to evaluate its value in differential diagnosis.Results: WT1 overexpression rate and mean WT1 expression level were significantly higher in MDS compared to AA (P = 0.000 and P = 0.013, respectively). Patients with RCC and normal cytogenetics exhibited significantly greater portion of patients exposing WT1 overexpression, compared to all AA subtypes (P = 0.001, P = 0.000 and P = 0.001, respectively). ROC curve analysis revealed that WT1 expression could differentiate between RCC with normal cytogenetics and non-severe AA. Based on a cut-off value of 1.45%, WT1 expression provided a sensitivity of 23.2% and a specificity of 100%.Discussion: In the present study, WT1 overexpression rate was gradually decreased in RAEB group, RCC group and AA subtypes, and the mean WT1 expression level of the MDS patients was significantly higher than that of the AA group. It is very difficult to differentiate between RCC with normal cytogenetics and NSAA in children. Our results showed significant differences in WT1 overexpression rate between these two groups. When we set the cut-off value as 1.45%, WT1 expression levels could be used to differentiate between cases of RCC with normal cytogenetics and NSAA in children.Conclusion: WT1 expression might be useful for distinguishing between myelodysplastic syndrome and aplastic anemia in children.

Prediction of FLAG ± Ida Regimen Efficacy in Patients with Relapsed/ Refractory Acute Myeloid Leukemia

Aim. To assess the efficacy of FLAG/FLAG-Ida regimen and to identify factors that influence remission, duration of disease-free survival (DFS) and overall survival (OS) of patients with relapsed/refractory acute myeloid leukemia (AML). Materials &amp; Methods. The trial included 54 patients (28 men and 26 women), median age was 37 years (range 18-70 years). 27 (50 %) out of 54 patients had refractory AML and 27 (50 %) patients had relapsed AML. FLAG and FLAG-Ida regimens were administered as induction therapy. 37 (68.5 %) patients received bone marrow transplantation. Molecular genetic and cytogenetic examinations were performed prior to therapy and on the 28&lt;sup&gt;th&lt;/sup&gt; day after the start of treatment. WT1 gene expression was evaluated on the 14&lt;sup&gt;th&lt;/sup&gt;-16&lt;sup&gt;th&lt;/sup&gt; day of treatment. Results. Complete remission (CR) was achieved in 42 (77.8 %) out of 54 patients. Refractoriness to therapy was observed in 9 (16.7 %) out of 54 patients, mortality was 5.5 % (3/54). Remission rate was higher in patients with relapsed AML compared with refractory AML: 85.2 % (23/27) and 70.4 % (19/27), respectively. On the 14&lt;sup&gt;th&lt;/sup&gt;-16&lt;sup&gt;th&lt;/sup&gt; day of treatment patients with blast cell count ≥ 10 % in bone marrow (BM) showed significantly lower CR rate (60 %) compared with the group of patients with &lt; 10 % blast cells in BM (89.6 %; p = 0.024) and shorter DFS (median 7.6 vs. 17.6 months, respectively; p = 0.03). Median DFS in patients with WT1 expression reduction to &lt; 1 log on the 14&lt;sup&gt;th&lt;/sup&gt;-16&lt;sup&gt;th&lt;/sup&gt; day was 5 vs. 18 months in patients without WT1 expression reduction (p = 0.01). DFS varied in groups of patients with blast cell count &lt; 10 % in BM on the 14&lt;sup&gt;th&lt;/sup&gt;-16&lt;sup&gt;th&lt;/sup&gt; day of treatment based on the level of WT1 expression reduction (p = 0.04). MRD-negative patients (57.1 %) showed significantly longer DFS and OS compared with MRD-positive patients (median DFS was 17.6 vs. 5.2 months, respectively, p = 0.02; median OS was 19 vs. 6.9 months, p = 0.0002). Median DFS and OS were different only in ELN low- and high-risk groups (median not reached vs. 5.2 months, respectively, p = 0.039; median not reached vs. 10.2 months, p = 0.039). Conclusion. FLAG and FLAG-Ida are effective and safe regimens in the treatment of relapsed/refractory AML. Achieving remission depends on neither the risk group nor the time of relapse occurrence. The blast cell count in BM on the 14&lt;sup&gt;th&lt;/sup&gt;-16&lt;sup&gt;th&lt;/sup&gt; day of FLAG/FLAG-Ida treatment is a prognostic factor determining achievement and duration of remission. WT1 expression level in the early post-induction period is a sensitive DFS marker. MRD status and molecular genetic risk (ELN) group affiliation are essential prognostic factors determining DFS and OS.

WT1 Gene Overexpression in Differential Diagnosis of Ph-Negative Myeloproliferative Disorders

Aim. To assess the rate of WT1 gene overexpression and its clinical value in Ph-negative myeloproliferative disorders (MPD). Materials &amp; Methods. The trial included 72 patents with Ph-negative MPD. Among them there were patients with primary myelofibrosis (MF; n = 32), post-polycythemia vera MF (n = 7), polycythemia vera (PV; n = 17), and essential thrombocythemia (ET; n = 16) with median age of 57 years (range 19-78 years). Median (range) time from diagnosis to the date of evaluating WT1 expression in PV, ET, and MF was 9.4 (0-309), 14.4 (0-55), and 21.4 months (0-271 months), respectively. WT1 expression in terms of WT1 copies/10&lt;sup&gt;4&lt;/sup&gt; ABL copies was measured by quantitative PCR. Results. WT1 gene overexpression is revealed solely in patients with MF (in 34/39; 87 %). In PV/ET no WT1 gene overexpression was observed. Median WT1 expression in MF was 230/10&lt;sup&gt;4&lt;/sup&gt; ABL copies (range 42.2-9,316.45/10&lt;sup&gt;4&lt;/sup&gt; ABL copies). Sensitivity and specificity of WT1 gene overexpression in MF with respect to PV/ET were 87 % and 100 %, respectively. A distinct correlation was identified between WT1 gene expression level and spleen size, duration of the disease, blast cell count, and DIPSS risk group. WT1 gene expression level could be correlated neither with age and sex, nor with MF mutation status and leucocyte, thrombocyte, and haemoglobin levels. Conclusion It appears that due to a high specificity and sensitivity of WT1 gene expression in MF it can be used as a marker for differential diagnosis of Ph-negative MPD. A correlation between WT1 gene expression and tumor mass in MF cannot be excluded. It is advisable to analyze the dynamics of WT1 expression level to predict the efficacy of current targeted therapy.

Measurable Residual Disease Assay with WT1 Expression in Acute Myeloid Leukemia Who Underwent Allogeneic Hematopoietic Stem Cell Transplantation; Optimal Threshold, Time Points, and Candidates

BackgroundOverexpression of WT1 is a surrogate marker of abnormal myelopoiesis and has been evaluated as a potential tool to assess measurable residual disease (MRD) in myeloid malignancies. Given that lack of consensus on clinically relevant WT1 thresholds and time points in the allogeneic hematopoietic cells transplantation (allo-HSCT) setting, WT1 quantification has not yet gained widespread use despite several pieces of evidence demonstrating the possible role for MRD assessment with the limited numbers of patients. To investigate optimal threshold, time points, and candidates of WT1 quantification in AML, we retrospectively analyzed a large cohort of consecutive patients who underwent allo-HSCT at Catholic Hematology Hospital.Patients and methodsThis study included 425 consecutive patients with AML who underwent allo-HSCT at CR state from either a matched siblings (n=199), matched unrelated (n=117) or haploidentical family donors (n=109) from 2012 to 2016. Patients were in the first (n=400) or second (n=25) complete remission with a median age of 48 years (range, 18~70). Favorable, intermediate, poor risk groups by 2017 NCCN criteria were 28% (n=120), 49% (n=206), and 23% (n=99), respectively. Bone marrow WT1 levels before, and at 1 or 3 months after allo-HSCT were determined using real-time PCR using the ELN normalized method. We sought to clarify the prognostic relevance of the WT1 quantification regarding the cumulative incidence of relapse (CIR) and survival outcomes.ResultsWith a median follow-up of 39 months (range, two days to 73 months), the 4-year overall survival, disease-free survival, CIR and non-relapse mortality were 63.6%±2.6%, 61.5%±2.6%, 17.9%±2.1% and 24.7%±2.5%, respectively.Analysis of dynamic changes of WT1 levels demonstrated decreased levels at 1 (n=333, mean 86 copies, range 0~1800) and three months (n=346, mean 101 copies, range 0~1670) after allo-HSCT compared to before allo-HSCT (n=425, mean 219 copies, range 0~9630). Relapsed patients had significantly higher WT1 levels before (P=0.018) and at three months (P=0.041) after allo-HSCT, whereas no difference at one month after allo-HSCT (P=0.167). Even the ROC curve analysis revealed that WT1 levels before allo-HSCT were significantly available to predict CIR after allo-HSCT (P<0.001). Among various cut-off levels of WT1 expression (median, 25% from the top, and cut off by ELN), cutoff by ELN (250 copies) was most effective for predicting CIR. The CIR of MRD positive patients (³ 250 copies) before and at three months after allo-HSCT were 43% (vs. 14%, P<0.001) and 35% (vs. 11%, P<0.001), respectively. In multivariate analysis, the WT1-MRD positivity independently predicted the CIR (before, HR=3.5, P<0.001; at three months, HR=7.4, P<0.001), which translated into inferior disease-free survival (P<0.001) and overall survival (P<0.001). In a subgroup analysis with the WT1-MRD positive patients before allo-HSCT (n=44), the WT1-MRD positivity at three months was significantly effective to identify patients with a higher risk for relapse (100% vs. 26%, P<0.001).In subgroup analyses in each risk group by 2017 NCCN criteria, the WT1-MRD positivity before allo-HSCT was significantly effective to predict CIR in the intermediate risk group (57% vs. 12%, P<0.001), whereas no significance in both favorable and poor risk groups. On the other hand, the WT1-MRD positivity at three months after allo-HSCT was effective to predict CIR in the poor risk group (60% vs. 21%, P<0.001). In patients with normal karyotype without NPM1 mutations (n=117), the WT1-MRD positivity before allo-HSCT significantly predict CIR (32% vs. 8%, P=0.001), whereas no difference in patients with NPM1 mutations (n=66) or core-binding factor (CBF) AML (n=102).ConclusionsThese data suggest standardized bone marrow WT1 levels using the ELN threshold (250 copies) before and at three months after allo-HSCT provided relevant information to predict relapse in AML with intermediate and poor risk groups by 2017 NCCN criteria, respectively. The validated WT1 MRD assay by ELN was revealed to be particularly available in AML without specific MRD markers, such as NPM1 or CBF-AML, and different significance by times points should be considered for clinical applications to identify high-risk AML for relapse, potential candidates for various immunomodulatory approaches. DisclosuresKim:Pfizer: Research Funding; Ilyang: Research Funding; BMS: Research Funding; Novartis: Research Funding. Lee:Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Research Funding.

Efficacy of Chemotherapy in Acute Leukemia Patients Resistant to Previous Standard Treatment According to the Series Measurement of WT1 Gene Expression

Aim. To estimate the efficacy of chemotherapy in acute leukemia patients resistant to previous standard treatment according to the series measurement of WT1 expression. Materials &amp; Methods. The series measurement of WT1 expression formed the basis of the efficacy estimation of induction chemotherapy in 31 patients (15 men and 16 women aged from 3 months to 68 years; the median age was 28 years) with prognostically unfavourable variants of acute myeloid (AML) and lymphoblastic leukemia (ALL) (23 AML and 8 ALL patients). The WT1 gene expression was measured at baseline and 2-3 weeks after the treatment by the quantitative real-time PCR. The threshold level for detection was 250 copies of WT1/10&lt;sup&gt;4&lt;/sup&gt; copies of ABL. The cytogenetic profile of leukemia cells was assessed by standard cytogenetics and FISH. Results. The baseline expression level of WT1 varied from 305 to 58,569 copies/10&lt;sup&gt;4&lt;/sup&gt; copies of ABL. The expected reduction of WT1 expression after the first induction chemotherapy treatment was reported in 22/23 (96 %) AML patients and in 6/8 (75 %) ALL patients. According to our results WT1 expression reached the threshold in 13/31 (42 %) patients, including 9 AML patients and 4 ALL patients. After 11/31 (35 %) patients received the second course of treatment, WT1 expression level became normal in 8 cases (5 ALL and 3 AML patients). Despite high dose chemotherapy, HSCT and such agents as blinatumomab and gemtuzumab, an unfavourable outcome was observed in 18/31 (58 %) patients including 6 patients with complex karyotype (CK+) and 2 patients with monosomal karyotype (MK+). Once the MK+ and CK+ combination was observed, in another case the MK+ was combined with the prognostically unfavourable inv(3)(q21q26) inversion. Conclusion. Our results show that the molecular monitoring should be included as part of treatment of the prognostically unfavourable acute leukemia. The WT1 gene was shown to be the most appropriate marker. WT1 expression was shown to correlate with the common fusion genes allowing to estimate the blast cell count at the molecular level.

Protective Effect of Valsartan on Podocyte Injury in Rats with Diabetic Nephropathy

To investigate the mechanism of valsartan protecting podocytes and inhibiting renal injury in diabetic rats. The rat model of diabetic nephropathy was induced by combination of valsartan and high-sugar and high-fat diet. The urinary protein content, renal index, inflammatory and antioxidant indexes in the kidney, renal pathological changes and podocyte holes were investigated. Membrane WT1 and P-Cadherin protein expression levels. Compared with the model group, the 24h urine protein content of valsartan was significantly decreased (P<0.05). Valsartan significantly inhibited the body weight of the model group (P<0.01), and significantly inhibited The increase of renal index (P<0.05); the high and middle doses of valsartan could significantly reduce the levels of IL-β, TNF-α and IL-6 in rat kidney (P<0.05-0.01). The valsartan high and middle dose groups significantly reduced MDA content in rat kidney (P<0.05), and significantly increased SOD activity (P<0.05). HE and PAS staining showed that valsartan was used in model group rats. The pathological changes were alleviated, and the glomerular morphology returned to normal. The protein expression of WT1 and P-Cadherin in the kidney of DN rats by Western blot showed that P- in the kidney tissue of valsartan rats. The expression levels of Cadherin and WT1 protein were significantly increased (P<0.05). Valsartan can regulate the expression of podocyte membrane proteins WT1 and P-Cadherin to protect podocytes, and then repair renal function and anti-diabetic nephropathy.

A Proposed Kinetic Model for the Diagnostic and Prognostic Value of WT1 and p53 in Acute Myeloid Leukemia.

Wilms tumor (WT1) and p53 proteins were identified in the pathogenesis of several malignancies, including hematological malignancies. As a result of their interaction and diverse context-specific functions, this study aimed to emphasize the diagnostic and prognostic impacts of WT1 and p53 expression in acute myeloid leukemia (AML). Twelve bone marrow (BM) biopsies were obtained from AML patients who were diagnosed in accordance with the French-American-British diagnostic criteria. For comparative purposes, nine normal BM biopsies were included. The expression rate of WT1 and p53 were determined by an immunohistochemistry assay. A significantly higher (p < 0.005) and strongly correlated ( = 0.855, p = 0.001) expression rates of WT1 and p53 were observed in the BM of AML patients in comparison to control BM. Furthermore, relapsed AML patients had significantly higher expression of WT1, but not p53, when compared to newly diagnosed patients. In regard of patient's responsiveness to chemotherapy, no significant difference was reported between good and poor responders. However, the relative ratio of p53 to WT1 expression was evidently correlated to the responsiveness groups (p < 0.05), where the ratio was observed to be significantly higher among poor responders. Poor responders were characterized by a statistically significant and dominant p53 expression (p53/WT1 > 1.0) while both good responding patients and control subjects had a dominant WT1 expression (p53/WT1 < 1.0). The enhanced expression levels of WT1 and p53 proteins in the BM of AML patients is supportive of their intermediate role in the pathogenesis of the disease. WT1 expression rate may encompass a negative prognostic value of the disease. Furthermore, the ratio of p53/WT expression may serve as a hallmark of the patient's responsiveness to chemotherapy, where a dominant WT1 expression may reveal good responsiveness to chemotherapy. Herein, we are proposing a kinetic model where the p53/WT1 ratio might be useful as a laboratory approach to evaluate the prognostic value of AML including the patient's responsiveness to chemotherapeutic regimen.

Validation of a Molecular Risk Score for Prognosis of Patients With Acute Promyelocytic Leukemia Treated With All-trans Retinoic Acid and Chemotherapy-containing Regimens.

Although treatment of acute promyelocytic leukemia (APL) has evolved dramatically during the past decades, especially with the introduction of all-trans retinoic acid, risk stratification remains an important issue. To date, relapse risk can be predicted by leukocyte and platelet counts only. In the present report, we present a validation study on 3 candidate genes and a newly developed molecular risk score for APL in 2 independent patient cohorts. An integrative risk score combining the expression levels of BAALC, ERG, and WT1 was calculated for 79 de novo APL patients from the original cohort and 76 de novo APL patients from a validation cohort. Gene expression analysis was executed the same for both cohorts, and the results regarding the effect on patient outcomes were compared. The expression levels of BAALC, ERG, and WT1 were similar in both cohorts compared with the healthy controls. The relapse and survival rates were not different between the low- and high-risk patients according to the Sanz score. However, application of the molecular risk score on the validation cohort distinctly discriminated patients according to their risk of relapse and death just as in the original APL cohort, although single gene analyses could not reproduce the negative prognostic impact. The analysis clearly validated the prognostic effect of the integrative risk score on the outcome in APL patients. The value was further empowered because the single gene analyses did not show similar results. Whether the integrative risk score retains its prognostic power in the chemotherapy-free setting should be investigated further.

Heat shock protein 70/nitric oxide effect on stretched tubular epithelial cells linked to WT-1 cytoprotection during neonatal obstructive nephropathy.

Mechanical stress is a key pathogenic driver of apoptosis in the tubular epithelium in obstructive nephropathy. Heat shock protein 70 (Hsp70) and Wilms' tumor (WT-1) have been proposed to represent linked downstream effectors of the cytoprotective properties of NO. In the present study, we sought to evaluate whether the cytoprotective effects of L-arginine in neonatal obstructive nephropathy may be associated with NO-dependent increases in WT-1 and Hsp70 expression. Neonatal Wistar-Kyoto rats were submitted to complete unilateral ureteral obstruction (UUO) and treated thereafter with vehicle, L-NAME or L-arginine by daily gavage for 14days to block or augment NO levels, respectively. Normal rat kidney epithelial cells by NRK-52E were exposed to mechanical stress in vitro in the presence or absence of L-NAME, L-arginine, sodium nitroprusside (SNP), L-arginine+SNP or L-arginine/L-NAME. Induction of apoptosis and the mRNA expression of WT-1 and Hsp70 genes were assessed. WT-1 and Hsp70 genes expression decreased in the presence of L-NAME and following UUO coincident with increased tubular apoptosis. L-arginine treatment increased NO levels, reduced apoptosis and restored expression levels of WT-1 and Hsp70 to control levels. L-arginine treatment in vitro reduced basal apoptotic rates and prevented apoptosis in response to mechanical strain, an effect enhanced by SNP co-incubation. L-NAME increased apoptosis and prevented the anti-apoptotic action of L-arginine. L-arginine treatment in experimental neonatal UUO reduces apoptosis coincident with restoration of WT-1 and Hsp70 expression levels and directly inhibits mechanical strain-induced apoptosis in an NO-dependent manner in vitro. This potentially implicates an NO-Hsp70-WT-1 axis in the cytoprotective effects of L-arginine.