Tumor-1 Gene Research Articles

WT1-guided pre-emptive therapy after allogeneic hematopoietic stem cell transplantation in patients with acute myeloid leukemia.

Measurable residual disease (MRD)-guided pre-emptive therapies are now widely used to prevent post-transplant hematological relapse in patients with acute myeloid leukemia (AML). This single-center retrospective study aimed to clarify the significance of pre-emptive treatment based on Wilms' tumor gene-1 mRNA (WT1) monitoring for MRD in patients with AML who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT). Patients with AML who received chemotherapy for hematological relapse or WT1 increase after allo-HSCT were eligible for inclusion. From January 2017 to June 2022, 30 patients with a median age of 57 (16-70) years were included and stratified into two groups: 10 with WT1 increase and 20 with hematological relapse. The median times from HCT to WT1 increase or hematological relapse were 309days (range: 48-985) or 242days (range: 67-1116), respectively. Less intensive chemotherapy using azacitidine or cytarabine was selected for all patients with WT1 increase and 12 (60%) with hematological relapse. The 1-year overall survival and event-free survival rates for WT1 increase and hematological relapse were 70% vs. 44% (P = 0.024) and 70% vs. 29% (P = 0.029), respectively. These real-world data suggest that WT1-guided pre-emptive therapy may be superior to therapy after hematological relapse in patients with AML who have undergone allo-HSCT.

Wilms' tumor gene 1: lessons from the interface between kidney development and cancer.

In 1990, mutations of the Wilms' tumor-1 gene (WT1), encoding a transcription factor in the embryonic kidney, were found in 10-15% of Wilms' tumors; germline WT1 mutations were associated with hereditary syndromes involving glomerular and reproductive tract dysplasia. For more than three decades, these discoveries prompted investigators to explore the embryonic role of WT1 and the mechanisms by which loss of WT1 leads to malignant transformation. Here, we discuss how alternative splicing of WT1 generates isoforms that act in a context-specific manner to activate or repress target gene transcription. WT1 also regulates posttranscriptional regulation, alters the epigenetic landscape, and activates miRNA expression. WT1 functions at multiple stages of kidney development, including the transition from resting stem cells to committed nephron progenitor, which it primes to respond to WNT9b signals from the ureteric bud. WT1 then drives nephrogenesis by activating WNT4 expression and directing the development of glomerular podocytes. We review the WT1 mutations that account for Denys-Drash syndrome, Frasier syndrome, and WAGR syndrome. Although the WT1 story began with Wilms' tumors, an understanding of the pathways that link aberrant kidney development to malignant transformation still has some important gaps. Loss of WT1 in nephrogenic rests may leave these premalignant clones with inadequate DNA repair enzymes and may disturb the epigenetic landscape. Yet none of these observations provide a complete picture of Wilms' tumor pathogenesis. It appears that the WT1 odyssey is unfinished and still holds a great deal of untilled ground to be explored.

Comparative immunohistochemical analysis of WT-1, Syndecan and Snail in Ameloblastoma and odontogenic keratocyst: A retrospective study.

The purpose of this experimental study was to evaluate and compare the degree of expression of Wilm's Tumor Gene-1 (WT-1), Syndecan (CD 138) and Snail in Ameloblastoma and odontogenic keratocyst (OKC) and to analyse their potential role in pathogenesis. Immunohistochemical analysis was performed to evaluate WT-1, Syndecan and Snail expression in Ameloblastoma (n = 20) and OKC (n = 20). Topographical immunoexpression pattern of Ameloblast-like cells, Stellate Reticulum-like cells in Ameloblastoma and basal layer as well as suprabasal layer of cells of OKC were also compared. The results obtained were subjected to ANOVA test and Tukey HSD test through SPSS software 20.0 for Microsoft Windows. WT-1 and Snail overexpression was seen in both Ameloblastoma and OKCs. Syndecan, responsible for maintaining normal cellular morphology, cell-cell adhesion and differentiation was significantly downregulated in both the lesions. The Ameloblasts-like cells and the basal cells showed significantly higher immunopositivity for WT-1 and Syndecan as compared to that of basal cells. An inverse relation was noted for Snail protein. The ANOVA test predicted a statistically significant difference of expression across the lesions with a P value <0.0001 for Syndecan and Snail. The under-expression of epithelial membrane protein Syndecan-1 and upregulation of EMT transcription factor Snail can promote local invasion and is indicative of poor prognosis of these lesions. The overexpression of WT-1 results in tumorigenesis, proliferation and localized aggressiveness of Ameloblastoma and intrabony growth of OKC. Further investigation on the biologic behaviour of OKC is still recommended to arrive at more specific conclusions regarding its nature.

The FLT3 internal tandem duplication mutation at disease diagnosis is a negative prognostic factor in myelodysplastic syndrome patients

The role of the FMS-like tyrosine kinase 3 (FLT3) gene in acute myeloid leukemia (AML) has been well documented and the FLT3-internal tandem duplication (FLT3-ITD) mutation has been identified as a prognostic factor in AML. Due to its low incidence, the role of the FLT3 mutation remains unclear in myelodysplastic syndrome (MDS) patients. To investigate the impact of the FLT3-ITD status on the prognosis of MDS at diagnosis, we retrospectively analyzed 72 MDS patients admitted to Teikyo University Hospital. FLT3-ITD was examined by a reverse transcription-polymerase chain reaction using complementary DNA synthesized from mRNA extracted from bone marrow mononuclear cells at the diagnosis of MDS. Fifteen patients (20.8 %) were positive for FLT3-ITD and had significantly worse overall survival (OS) and progression-free survival (PFS) than patients who were negative (P < 0.001 and P < 0.001, respectively) in a multivariate analysis. We also investigated whether the Wilms’ tumor gene-1 (WT-1) copy number was associated with the FLT3-ITD mutational status using data available on WT-1 from 57 patients. A WT-1 transcript copy number ≥50/μg total mRNA in peripheral blood was detected in 35 patients (61.4 %). All FLT3-ITD-positive patients showed WT-1 ≥50. The FLT3-ITD-positive group showed significantly higher WT-1 transcription levels than the negative group. These results indicate that the FLT3-ITD mutation has a prognostic impact at the diagnosis of MDS and is associated with a high level of WT-1.

Histomorphological Features of Ovarian Neoplasms and Expression of p53 and WT1 in Surface Epithelial Tumours: A Cross-sectional Study

Introduction: Ovary is the most common site of neoplastic and non neoplastic lesion, can present in childhood to postmenopausal age group and remain the most lethal of all gynaecological malignancies. Tumour Protein (p53) gene mutations or deletions are most common in ovarian carcinoma. However, Wilms' Tumor gene1 (WT1) and p16 expression are also seen in serous ovarian carcinoma. These Immunohistochemistry (IHC) marker are useful in the differential diagnosis of serous ovarian carcinomas. Aim: To study histomorphology of ovarian neoplasm along with expression of p53 and WT1 in surface epithelial tumours and to assess the prevalence of various ovarian neoplasms in different age groups. Materials and Methods: This cross-sectional study was conducted in Department of Pathology, Sarojini Naidu Medical College, Agra, Uttar Pradesh, India, over a period of two years (from September 2018-September 2020). A total of 78 ovarian specimen received in histology laboratory was studied for gross and microscopic features. The p53 and WT1 IHC expression pattern was studied in surface epithelial tumours. Statistical significance was calculated in relation to p53 and WT1 expression with histological type and grade of tumour using Chi-square test. Results: A total of 78 cases were studied, out of which benign tumours were the most common 40 (51.3%) cases, followed by malignant tumours 32 (41.0%) cases and borderline malignancy 6 (7.7%) cases. The most common benign lesions were mucinous cystadenoma 20 (50%) cases. Serous carcinomas were most common malignant tumours 19 (59.3%) cases followed by Germ Cell Tumours (GCT) 5 (15.6%) cases. All benign and borderline epithelial ovarian tumours were found p53 and WT1 negative. Out of 22 cases of malignant surface epithelial tumour, 14 (63.6%) and 12 (54.4%) were positive for p53 and WT1 respectively and all were serous carcinomas. Conclusion: Ovarian lesions present with wide spectrum of histomorphological features. The p53 and WT1 show different rates of expression and staining pattern in various epithelial ovarian carcinomas. Hence routine gross, proper histological examination and correct IHC interpretation is required for specific diagnosis.

AIM2 Suppresses Inflammation and Epithelial Cell Proliferation during Glomerulonephritis.

Absent in melanoma-2 (AIM2) is an inflammasome-forming innate immune sensor for dsDNA but also exhibits inflammasome-independent functions such as restricting cellular proliferation. AIM2 is expressed in the kidney, but its localization and function are not fully characterized. In normal human glomeruli, AIM2 localized to podocytes. In patients with glomerulonephritis, AIM2 expression increased in CD44+-activated parietal epithelial cells within glomerular crescents. To explore AIM2 effects in glomerular disease, studies in Aim2 -/- mice were performed. Aim2-/- glomeruli showed reduced expression of Wilm tumor gene-1 (WT1), WT1-driven podocyte genes, and increased proliferation in outgrowth assays. In a nephrotoxic serum (NTS)-induced glomerulonephritis model, Aim2-/- (B6) mice exhibited more severe glomerular crescent formation, tubular injury, inflammation, and proteinuria compared with wild-type controls. Inflammasome activation markers were absent in both Aim2 -/- and wild-type kidneys, despite an increased inflammatory transcriptomic signature in Aim2 -/- mice. Aim2 -/- mice also demonstrated dysregulated cellular proliferation and an increase in CD44+ parietal epithelial cells during glomerulonephritis. The augmented inflammation and epithelial cell proliferation in Aim2 -/- (B6) mice was not due to genetic background, as Aim2 -/- (B6.129) mice demonstrated a similar phenotype during NTS glomerulonephritis. The AIM2-like receptor (ALR) locus was necessary for the inflammatory glomerulonephritis phenotype observed in Aim2 -/- mice, as NTS-treated ALR -/- mice displayed equal levels of injury as wild-type controls. Podocyte outgrowth from ALR -/- glomeruli was still increased, however, confirming that the ALR locus is dispensable for AIM2 effects on epithelial cell proliferation. These results identify a noncanonical role for AIM2 in suppressing inflammation and epithelial cell proliferation during glomerulonephritis.

Gene and histomorphology alteration analysis in spermatogenesis arrest mouse model: a probable novel approach for infertility.

IntroductionApproximately 15% of couples in the reproductive age are struggling with infertility which, in nearly half of them, is caused by male factors.Material and methodsThe present study comprised of two groups of sixteen C57BL/6 mice; each mouse received either an intraperitoneal injection of 30 mg/kg of an alkylating agent or the same amount of distilled water. Testes were harvested 30 days following the injection. Morphometric analysis of hematoxylin and eosin (H&E) stained slides including mean tubular area, diameter and intratubular particles were performed. Spermatogenesis rate was assessed by spermatogonial markers including promyelocytic leukemia zinc finger protein (PLZF) and neurogenin-3 (NGN3). Moreover, the expression rate of Wilms Tumor-1 (WT-1), A-Kinase Anchoring Protein 4 (AKAP4) and adenosine deaminase domain containing 1 (ADAD1) genes were evaluated via real-time polymerase chain reaction (RT-PCR).ResultsThe body weight gradually increased in both groups after a period of 30 days, however, the increase was significantly (p-value = 0.023) lower in the chemically treated group. All the morphometric parameters were considerably decreased in the azoospermic mice. Also, promyelocytic leukemia zinc finger protein and neurogenin-3 expression dramatically declined (p-value <0.001 for both markers). In comparison with the negative control group, the expression rates of A-Kinase Anchoring Protein 4 and adenosine deaminase domain containing 1, two genes participating in the sperm structure, were remarkably reduced in the intervention group (p-value <0.001); however, our investigations demonstrated that the azoospermia model could induce a 5-fold upregulation in Wilms Tumor-1 gene expression.ConclusionsDevelopment of an azoospermia model can upregulate Wilms Tumor-1 gene expression in a higher rate after 30 days; however, expression of the testis-specific genes, A-Kinase Anchoring Protein 4 and adenosine deaminase domain containing 1, decreased after the intervention. To the best of our knowledge, this upregulation could be related to spermatogenesis recovery after the follow-up period.

The Proportional Relationship Between Pretransplant WT1 mRNA Levels and Risk of Mortality After Allogeneic Hematopoietic Cell Transplantation in Acute Myeloid Leukemia Not in Remission.

The relationship between the expression levels of Wilms' tumor-1 gene (WT1) mRNA in peripheral blood before allogeneic hematopoietic cell transplantation (allo-HCT) and risk of mortality in acute myeloid leukemia (AML) patients in noncomplete remission (non-CR) remains quite elusive. We retrospectively assessed the impact of the pretransplant WT1 mRNA level on survival after allo-HCT in non-CR AML patients. A total of 125 AML patients, including 46 non-CR patients (36.8%), were analyzed. On multivariate analysis of non-CR AML patients, WT1 mRNA ≥5000 copies/μg RNA was significantly related to increased risk of mortality (hazard ratio, 2.7; 95% confidence interval, 1.3-5.5; P = 0.008). Furthermore, in the entire cohort, log10-transformed WT1 mRNA before allo-HCT was found to be significantly associated with the increased risk of mortality irrespective of whether the disease status was CR or non-CR, using Akaike's information criterion. As the pretransplant WT1 mRNA level elevated, the hazard ratio of mortality monotonically increased in a nonlinear manner regardless of remission status, suggesting that WT1 mRNA level in peripheral blood might reflect tumor burden. This study demonstrated that the pretransplant WT1 mRNA level was a powerful prognostic factor in allo-HCT even for non-CR AML patients, and there may be a WT1 mRNA threshold in non-CR patients for benefiting from allo-HCT.

Research progress on the relationship among Wilms’ tumor-1 gene and its coding proteins and tumor

Wilms’ tumor-1 gene (WT1) was first discovered in children with Wilms tumor and considered as a tumor suppressor gene. Since then, it has been confirmed that the abnormal expression of WT1 was related to many urinary and reproductive system diseases. And WT1 has been proved to be an oncogene in leukemia, lung cancer, breast cancer, pancreatic cancer and other malignant tumors. In this study, the role of WT1 and its coding proteins in tumor and tumor immunotherapy targeting WT1 were reviewed. Key words: Wilms’ tumor-1 protein; Leukemia; Malignant neoplasms; Immunotherapy

Abstract CT114: INO-5401 and INO-9012 delivered by electroporation (EP) in combination with cemiplimab (REGN2810) in newly-diagnosed glioblastoma (GBM) (NCT03491683)

Abstract Despite advances in therapy, glioblastoma (GBM) remains one of the most deadly cancers, with five-year survival under 5%. Newer immunotherapies hold promise in the treatment of GBM, and T cell-enabling therapies may improve progression-free and overall survival for newly-diagnosed patients. Checkpoint inhibitors, such as PD-1 inhibitors, have increased response rates in many cancers, but not yet in GBM. In this study, a novel antigen-specific T cell-generating therapy, INO-5401, combined with INO-9012, together with a PD-1 checkpoint inhibitor, cemiplimab, will be given to patients with newly-diagnosed GBM in order to evaluate tolerability, immunogenicity and any activity of the combination. INO-5401 is a mixture of three synthetic plasmids that target Wilms tumor gene-1 (WT-1) antigen, prostate specific membrane antigen (PSMA), and human telomerase reverse transcriptase (hTERT) antigen. INO-9012 is a plasmid encoding human interleukin-12 (IL-12) p35 and p40 subunit proteins. In preclinical studies, targeting WT-1, PSMA and hTERT induced robust cellular immune responses and slowed tumor growth in murine tumor implantation and ALL models. This is a Phase I/IIA, open-label, multi-center trial to evaluate the safety, immunogenicity and preliminary clinical efficacy of INO-5401 + INO-9012 delivered by intramuscular (IM) injection followed by electroporation (EP), in combination with cemiplimab, and radiation and chemotherapy, in participants with newly-diagnosed GBM. INO-5401 + INO-9012 will be administered Q3w for the first four doses, and then Q9w until disease progression. Cemiplimab will be administered Q3w until disease progression. The trial population is divided into two cohorts: Cohort A are patients with an unmethylated O6-methylguanine-deoxyribonucleic acid (DNA) methyltransferase (MGMT) promoter; and Cohort B are patients with a methylated O6-methylguanine-deoxyribonucleic acid (DNA) methyltransferase (MGMT) promoter. Both cohorts will receive radiation and temozolomide (TMZ), if clinically indicated, in combination with study therapies. Cohort B will continue TMZ for a total of 6 cycles. A safety run-in will be performed with up to six participants (safety analysis participants) from Cohort A and Cohort B. Correlative studies include the assessment of antigen-specific cellular immune responses in peripheral blood and tumor tissue. Fifty-two patients are estimated to be enrolled, 32 in Cohort A and 18 in Cohort B. Enrollment began in May of 2018 and the trial is continuing to accrue as planned. Citation Format: David Reardon, Seema Nagpal, Scott Soltys, Steven Brem, Antonio Omuro, Macarena De La Fuente, Amy-Lee Bredlau, Isreal Lowy, Matthew Fury, Matthew Morrow, Kim Kraynyak, Trevor McMullan, Ashley L. Santo, Brian Sacchetta, Jeffrey Skolnik. INO-5401 and INO-9012 delivered by electroporation (EP) in combination with cemiplimab (REGN2810) in newly-diagnosed glioblastoma (GBM) (NCT03491683) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT114.

Abstract CT177: INO-5401 + INO-9012 in combination with atezolizumab for locally advanced unresectable or metastatic/recurrent urothelial carcinoma

Abstract Background: Advanced urothelial carcinoma (UCa; bladder cancer) remains a deadly disease with patients often failing to respond to, or ineligible for, platinum-based therapy. Checkpoint inhibitors (CPIs) have increased response rates, but a majority of patients remain refractory to such agents or relapse. In this study, a novel antigen-specific T cell-generating therapy, INO-5401, combined with INO-9012, together with a CPI will be given to patients with advanced UCa with the aim of demonstrating tolerability, immunogenicity and efficacy (ORR, DoR, PFS, OS) of the combination. INO-5401 is a mixture of three synthetic plasmids that target Wilms tumor gene-1 (WT-1) antigen, prostate specific membrane antigen (PSMA) and human telomerase reverse transcriptase (hTERT) antigen. INO-9012 is a plasmid encoding human interleukin-12 (IL-12) p35 and p40 subunit proteins. In preclinical studies, targeting WT-1, PSMA and hTERT induced robust cellular immune responses and slowed tumor growth in murine tumor implantation and ALL models. Methods: This is a Phase I/IIA, open-label, multi-center trial to evaluate the safety, immunogenicity and preliminary clinical efficacy of INO-5401 + INO-9012 delivered by intramuscular (IM) injection followed by electroporation (EP) in combination with atezolizumab in participants with locally advanced unresectable or metastatic/recurrent UCa. INO-5401 + INO-9012 is administered Q3w for the first 4 doses, Q6w for the next 6 doses and Q12w thereafter until disease progression. Atezolizumab will be delivered Q3w until disease progression. The trial population includes Cohort A patients with confirmed disease progression during or following treatment with anti-Programmed Death receptor-1/Programmed Death receptor Ligand-1 (anti-PD-1/PD-L1) therapy and Cohort B patients who are treatment naïve and ineligible for cisplatin-based chemotherapy. All patients must have locally advanced unresectable or metastatic/recurrent UCa, measurable disease without previously treated target lesions (unless progressed following therapy) and ECOG of 0-1. Patients must not have had any approved anti-cancer therapy within 2 weeks of enrollment, nor any investigational therapy within 4 weeks of enrollment, any other malignancies within 3 yrs of enrollment, any autoimmune disease, and any immunostimulatory or immunosuppressive treatments. A safety run-in will be performed with up to six patients from Cohort A. Correlative studies include the assessment of antigen-specific cellular immune responses in peripheral blood and tumor tissue. ClinicalTrials.gov NCT03502785. EudraCT 2018-000309-21. Enrollment: Eighty-five patients are estimated to be enrolled. Enrollment began May 2018 and is continuing to accrue as planned. The safety run-in has been completed (no DLTs were observed in participants dosed to date), and the study is now open to full enrollment. Citation Format: Jeffrey Skolnik, Noah Hahn, Joaquim Bellmunt, Samantha Rosencranz, Malissa Diehl, Matthew Morrow, Kimberly Kraynyak, Trevor McMullan. INO-5401 + INO-9012 in combination with atezolizumab for locally advanced unresectable or metastatic/recurrent urothelial carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT177.

SHOX2 and WT1 Promoter Methylation Correlates with the Lung Cancer in Iranian Patients

Lung cancer is among the most common cause of cancer death in the world. Since the disease is diagnosed in the middle or late stages of the cancer development a more efficient method for an early diagnosis of the disease is required. The main goal of this study was to investigate the correlation between aberrant promoter methylation of the two genes: SHOX2(Short stature homeobox 2) and WT1(Wilms’ tumor gene1), in the plasma samples of the Iranian lung cancer patients. Following filling questionnaires and obtaining the consent of all participants, 70 cases including 45 patients and 25 healthy controls who underwent bronchoscopy procedure in the Masih-Daneshvari Hospital in Tehran, the blood samples were collected. DNA extraction was done and treatment was performed by sodium bisulfite applying Qiagen DNA methylation kit and Methylation specific PCR(MSP) was performed. The results showed a frequency of 82.2% and 55.55% of the hypermethylation for the SHOX2 and WT1 gene promoters in the caces samples, respectively. Our study demonstrated that hypermethylation of SHOX2 and WT1 genes promoter regions might be involved in lung cancer. The methylation of SHOX2 and WT1 in the blood plasma could be considered as the competent biomarkers for an early diagnosis of the lung cancer as a noninvasive method.

The Proportional Association between WT1 mRNA Level in Peripheral Blood before Allogeneic Hematopoietic Cell Transplantation and Risk of Mortality in Acute Myeloid Leukemia Not in Remission

Abstract INTRODUCTION The prognosis for allogeneic hematopoietic cell transplantation (allo-HCT) is relatively poor in patients with acute myeloid leukemia (AML) who are not in remission (non-CR). Wilms' tumor-1 gene messenger ribonucleic acid (WT1 mRNA), which is overexpressed in almost all AML, has been used as an indicator of monitoring minimal residual disease (MRD) and has been regarded as one of the prognostic factors in AML patients with complete remission (CR). However, the association between the expression levels of WT1 mRNA in peripheral blood (WT1) before allo-HCT and risk of mortality in AML patients in non-CR remains quite elusive. We therefore assessed the effect of the pre-transplant WT1 level on survival after allo-HCT in AML patients in non-CR. METHODS We retrospectively analyzed data from consecutive patients undergoing allo-HCT at our institution between November 2007 and January 2017. We excluded patients who did not have an available WT1 value within 28 days before the start of conditioning. RESULTS A total of 125 AML patients, including 46 non-CR patients (36.8 %), were eligible for this study. The median age was 48 years (range: 17-68 years) and the number of males was 69 (55.2%). Forty-two patients (33.6%) had AML with myelodysplasia-related changes. This study included 34 patients (27.2%) who had undergone multiple transplantation. Myeloablative and reduced-intensity conditioning were used in 73 (58.4%) and 52 (41.6%) patients, respectively. In 63 patients who received transplants from either a related peripheral blood stem cell or bone marrow (BM) donor, four pairs (6.3%) were serologically mismatched for one antigen of HLA and 45 pairs (71.4%) received transplants from HLA haploidentical donors. In 32 patients who received transplants from an unrelated BM donor, seven pairs (21.9%) were serologically mismatched for one HLA antigen. Twenty-nine patients (23.2%) received unrelated cord blood transplantation. Among 46 non-CR patients, the median follow-up period among survivors was 1,092 days (range: 688-2,607 days) following allo-HCT. Receiver operating characteristic analysis for prediction of composite events including any cause of death or subsequent transplantation indicated that the best cutoff value for WT1 was 5,000 copies/ μg RNA in non-CR AML patients. Estimated two-year, event-free survival of non-CR patients with WT1 levels of less than 5,000 copies/ μg RNA was significantly higher than that of those with WT1 levels of 5,000 copies/ μg RNA or more (41.2% [95% confidence interval (CI), 18.6-62.6] vs 10.3% [95% CI, 2.6-24.3]; P=0.006). On multivariate analysis of the non-CR patients, WT1 5,000 copies/ μg RNA or more was significantly associated with increased risk of mortality (hazard ratio (HR), 2.7; 95% CI, 1.3-5.5; P=0.008). Log10-transformed WT1 (continuous scale) was also significantly related to increased risk of mortality (HR, 1.5; 95% CI, 1.0-2.1; P=0.037). In the entire cohort, log10-transformed WT1 (divided into four categories) before allo-HCT was found to be the most powerful prognostic factor of survival among remission status, cytogenetic risk group, and revised disease risk index, applying Akaike's information criterion. Moreover, under the assumption of a non-linear model, as the log10-transformed WT1 level rose, the HR of mortality increased monotonically; a non-linear fit was obtained using a restricted cubic spline function (three knots; Figure 1). CONCLUSION Our data showed that WT1 levels obtained before allo-HCT monotonically increased HR of mortality in a non-linear manner regardless of CR status. Of importance is the finding that WT1 levels before allo-HCT were proportionally correlated with probability of survival after allo-HCT in non-CR AML patients. This suggests that the level of expression of WT1 mRNA in peripheral blood might reflect tumor burden and that there may be a WT1 threshold in non-CR patients for benefiting from allo-HCT. Further prospective studies of WT1 are necessary to determine acceptable or feasible levels of disease activity for receiving allo-HCT in relapsed or refractory AML patients. Disclosures Nakamae: Otsuka Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Research Funding. Hino:Otsuka Pharmaceutical Co., Ltd.: Research Funding; Novartis: Research Funding. Nakamae:Otsuka Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Research Funding.

320 - Retrospective Analyses of Wilms Tumor Gene-1 Expression in Acute Myeloid Leukemia and Myelodysplastic Syndrome after Allogeneic Hematopoietic Stem Cell Transplantation

320 - Retrospective Analyses of Wilms Tumor Gene-1 Expression in Acute Myeloid Leukemia and Myelodysplastic Syndrome after Allogeneic Hematopoietic Stem Cell Transplantation

The Wilms' tumor gene-1 is a prognostic factor in myelodysplastic syndrome: a meta analysis.

Previous studies have suggested that Wilms’ tumor gene-1 (WT1) may be related to a decrease in both relapse-free survival (RFS) and overall survival (OS) for patients with myelodysplastic syndrome (MDS). Therefore, we conducted a meta-analysis on the utility of WT1 as a prognostic indicator of MDS. Published reports were searched in the following databases: Cochrane Library, PubMed, Embase, and Web of Science. The meta-analysis was conducted using the Cochrane Collaboration RevMan 5.2 software. Six publications with 450 total patients met the inclusion criteria and were subjected to further examination. The results showed a reduction in both overall survival (OS) and leukemia-free survival (LFS) with increasing WT1 expression levels: 1-year OS (odds ratio, OR = 0.16; 95% CI = 0.08–0.34, P < 0.001), 3-year OS (OR = 0.21; 95% CI = 0.09–0.47, P < 0.001), 5-year OS (OR = 0.24; 95% CI = 0.06–0.92, P = 0.04), 1-year LFS (OR = 0.06; 95% CI = 0.02–0.18; P < 0.001), 3-year LFS (OR = 0.20; 95% CI = 0.09–0.46; P < 0.001), and 5-year LFS (OR = 0.12; 95% CI = 0.04–0.38; P < 0.001). In terms of patients receiving hematopoietic stem cell transplantation, the cumulative incidence of relapse (CIR) was higher in the WT1 over-expression group than in the low-expression group: 1-year CIR (OR = 13.69; 95% CI = 2.99–62.62; P < 0.001), 3-year CIR (OR = 6.52; 95% CI = 2.31–18.40, P < 0.001). In conclusion, WT1 over-expression is a prognostic factor for MDS.

Low WT1 transcript levels at diagnosis predicted poor outcomes of acute myeloid leukemia patients with t(8;21) who received chemotherapy or allogeneic hematopoietic stem cell transplantation.

BackgroundAcute myeloid leukemia (AML) with t(8;21) is a heterogeneous disease. Identifying AML patients with t(8;21) who have a poor prognosis despite achieving remission is important for determining the best subsequent therapy. This study aimed to evaluate the impact of Wilm tumor gene-1 (WT1) transcript levels and cellular homolog of the viral oncogene v-KIT receptor tyrosine kinase (C-KIT) mutations at diagnosis, and RUNX1-RUNX1T1 transcript levels after the second consolidation chemotherapy cycle on outcomes.MethodsEighty-eight AML patients with t(8;21) who received chemotherapy only or allogeneic hematopoietic stem cell transplantation (allo-HSCT) were included. Patients who achieved remission, received two or more cycles of consolidation chemotherapy, and had a positive measureable residual disease (MRD) test result (defined as <3-log reduction in RUNX1-RUNX1T1 transcript levels compared to baseline) after 2–8 cycles of consolidation chemotherapy were recommended to receive allo-HSCT. Patients who had a negative MRD test result were recommended to receive further chemotherapy up to only 8 cycles. WT1 transcript levels and C-KIT mutations at diagnosis, and RUNX1-RUNX1T1 transcript levels after the second consolidation chemotherapy cycle were tested.ResultsPatients who had a C-KIT mutation had significantly lower WT1 transcript levels than patients who did not have a C-KIT mutation (6.7% ± 10.6% vs. 19.5% ± 19.9%, P < 0.001). Low WT1 transcript levels (≤5.0%) but not C-KIT mutation at diagnosis, a positive MRD test result after the second cycle of consolidation chemotherapy, and receiving only chemotherapy were independently associated with high cumulative incidence of relapse in all patients (hazard ratio [HR] = 3.53, 2.30, and 11.49; 95% confidence interval [CI] 1.64–7.62, 1.82–7.56, and 4.43–29.82; P = 0.002, 0.034, and <0.001, respectively); these conditions were also independently associated with low leukemia-free survival (HR = 3.71, 2.33, and 5.85; 95% CI 1.82–7.56, 1.17–4.64, and 2.75–12.44; P < 0.001, 0.016, and <0.001, respectively) and overall survival (HR = 3.50, 2.32, and 4.34; 95% CI 1.56–7.82, 1.09–4.97, and 1.98–9.53; P = 0.002, 0.030, and <0.001, respectively) in all patients.ConclusionsTesting for WT1 transcript levels at diagnosis in patients with AML and t(8;21) may predict outcomes in those who achieve remission. A randomized study is warranted to determine whether allo-HSCT can improve prognosis in these patients.

Vaccination with WT-1 (Wilms’ Tumor gene-1) peptide and BCG-CWS in melanoma

ejd.2011.1619 Auteur(s) : Megumi Nishioka1,a, Atsushi Tanemura1,a tanemura@derma.med.osaka-u.ac.jp, Sumiyuki Nishida3,a, Akiko Nakano2, Akihiro Tsuboi3, Yusuke Oji4, Yoshihiro Oka5, Ichiro Azuma6, Haruo Sugiyama2, Ichiro Katayama1 1 Department of Dermatology, 2 Department of functional Diagnostic Science, 3 Department of Cancer Immunotherapy, 4 Department of Cancer Stem Cell Biology 5 Department of Respiratory Medicine, Allergy and Rheumatic Diseases, Osaka University Graduate School of Medicine, 2-2, [...]

RARγ is Essential for Retinoic Acid Induced Chromatin Remodeling and Transcriptional Activation in Embryonic Stem Cells

We have utilized retinoic acid receptor γ (gamma) knockout (RARγ(-/-)) embryonic stem (ES) cells as a model system to analyze RARγ mediated transcriptional regulation of stem cell differentiation. Most of the transcripts regulated by all-trans retinoic acid (RA) in ES cells are dependent upon functional RARγ signaling. Notably, many of these RA-RARγ target genes are implicated in retinoid uptake and metabolism. For instance, Lrat (lecithin:retinol acyltransferase), Stra6 (stimulated by retinoic acid 6), Crabp2 (cellular retinoic acid binding protein 2), and Cyp26a1 (cytochrome p450 26a1) transcripts are induced in wild type (WT), but not in RARγ(-/-) cells. Transcripts for the transcription factors Pbx1 (pre-B cell leukemia homeobox-1), Wt1 (Wilm's tumor gene-1), and Meis1 (myeloid ecotropic viral integration site-1) increase upon RA treatment of WT, but not RARγ(-/-) cells. In contrast, Stra8, Dleu7, Leftb, Pitx2, and Cdx1 mRNAs are induced by RA even in the absence of RARγ. Mapping of the epigenetic signature of Meis1 revealed that RA induces a rapid increase in the H3K9/K14ac epigenetic mark at the proximal promoter and at two sites downstream of the transcription start site in WT, but not in RARγ(-/-) cells. Thus, RA-associated increases in H3K9/K14ac epigenetic marks require RARγ and are associated with increased Meis1 transcript levels, whereas H3K4me3 is present at the Meis1 proximal promoter even in the absence of RARγ. In contrast, at the Lrat proximal promoter primarily the H3K4me3 mark, and not the H3K9/K14ac mark, increases in response to RA, independently of the presence of RARγ. Our data show major epigenetic changes associated with addition of the RARγ agonist RA in ES cells.

The AG Genotype of the Wilms Tumor-1 rs16754 SNP Is Associated with Poor Outcome in Pediatric AML Patients Treated with Stem Cell Transplantation but Not in Adults

Abstract 5237The synonymous single nucleotide polymorphism rs16754 in the Wilms Tumor-1 gene (WT1) has been reported to correlate with outcome in adult patients with acute myeloid leukemia (AML) when treated with intensive chemotherapy. Specifically the GG genotype is significantly associated with favorable outcome, but also the AG genotype has been reported to be associated with better outcome as well. The clinical relevance of the rs16754 SNP in pediatric AML patients is far from clarified. In addition, it is not known whether allogeneic hematopoietic stem cell transplantation (HSCT) can modify the role of this SNP and its association with outcome. Methods:Genotyping of the SNP by direct sequencing of the exon 7 was performed on bone marrow samples from 86 AML patients (38 pediatrics and 48 adults). All patients were treated with HSCT. Most patients (39 adults and 28 pediatrics) were transplanted in first remission (CR1). The median age was 25 years (range: 14–54) for adults and 8 years (range: 8 months–14 years) for the pediatric group. Results:In pediatric AML, we detected the AA genotype in 22 patients (53%), the GG genotype in 2 patients (5%) and the remaining (42%) had AG genotype. In the adult patients, the AA genotypye was present in 26 patients (54%), GG genotype in 3 (6%) patients, and the AG genotype in the remaining patients (39%). A similar distribution was observed in the normal population (58%, 12%, 30%, for AA, GG, and AG, respectively). In pediatric patients, the AG genotype significantly correlated with shorter overall survival (OS) (P=0.04) and event free survival (EFS) (P=0.04) when compared with the patients with AA genotype. In contrast, in adult AML, groups with AG and AA geneotypes completely overlapped for OS and EFS. When only patients treated with HSCT in CR1 were considered, the pediatric patients showed the same trend (P=0.07), but there was no correlation with survival in the adult group. This analysis included patients with intermediate and adverse risk cytogenetics. AG genotype was not a predictor of outcome in multivariate model incorporating cytogenetics and the WT1 genotype. The patients with the GG genotype were too few for analysis. Conclusion:This data supports the concept that the biology of AML in pediatric patient is different from that in adults. The role of this synonymous SNP in AML needs further exploration, especially investigating the potential that this SNP may have some effects on the host and not only the disease. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Targetoid hemosiderotic hemangiomas (hobnail hemangiomas) are vascular lymphatic malformations: A study of 12 pediatric cases

Targetoid hemosiderotic hemangioma (THH), also called hobnail hemangioma, is a benign vascular lesion and thought to be of lymphatic origin. We sought to perform a clinicopathologic analysis of cases diagnosed as THH in a tertiary care children's hospital. Clinical and histopathologic data were obtained from a chart review of 12 confirmed pediatric cases of THH. To determine the presence or absence of lymphatic vessels in lesional biopsy specimens, we evaluated the expression of the lymphatic endothelial cell marker podoplanin using the D2-40 antibody. Wilms tumor-1 gene immunostaining and Ki-67 proliferation index were also performed to evaluate the proliferative nature of these lesions. Three children had a lesion since birth and 4 had a history of trauma before appearance of the THH. D2-40 immunostaining was positive in every case. Wilms tumor-1 gene immunostaining was negative in 9 cases, focally positive in two cases, and not performed in one case. The Ki-67 proliferation index was very low in all cases studied. The small number of cases and restriction to a pediatric population were limitations. Our findings suggest that THH should be classified as a lymphatic vascular malformation.