A Stromal Niche Defined by Expression of the Transcription Factor WT1 Mediates Programming and Homeostasis of Cavity-Resident Macrophages.

Tissue-resident macrophages require specific milieus for the maintenance of defining gene-expression programs. Expression of the transcription factor GATA6 is required for the homeostasis, function and localization of peritoneal cavity-resident macrophages. Gata6 expression is maintained in a non-cell autonomous manner and is elicited by the vitamin A metabolite, retinoic acid. Here, we found that the GATA6 transcriptional program is a common feature of macrophages residing in all visceral body cavities. Retinoic acid-dependent and -independent hallmark genes of GATA6+ macrophages were induced by mesothelial and fibroblastic stromal cells that express the transcription factor Wilms' Tumor 1 (WT1), which drives the expression of two rate-limiting enzymes in retinol metabolism. Depletion of Wt1+ stromal cells reduced the frequency of GATA6+ macrophages in the peritoneal, pleural and pericardial cavities. Thus, Wt1+ mesothelial and fibroblastic stromal cells constitute essential niche components supporting the tissue-specifying transcriptional landscape and homeostasis of cavity-resident macrophages.

Permissive ureter specification by TBX18-mediated repression of metanephric gene expression.

The murine kidney and ureter develop in a regionalized fashion from the ureteric bud and its surrounding mesenchyme. Whereas the factors that establish the metanephric cell lineages have been well characterized, much less is known about the molecular cues that specify the ureter. Here, we have identified a crucial patterning function in this process for Tbx18, a T-box transcription factor gene specifically expressed in the mesenchymal primordium of the ureter. Using misexpression and loss-of-function mice combined with molecular profiling approaches, we show that Tbx18 is required and sufficient to repress metanephric mesenchymal gene programs. We identify Wt1 as a functional target of TBX18. Our work suggests that TBX18 acts as a permissive factor in ureter specification by generating a mesenchymal domain around the distal ureteric bud where SHH and BMP4 signaling can occur.

Endothelial deletion of Wt1 disrupts coronary angiogenesis and myocardium development.

Wt1 encodes a zinc finger protein that is crucial for epicardium development. Although WT1 is also expressed in coronary endothelial cells (ECs), the abnormal heart development observed in Wt1 knockout mice is mainly attributed to its functions in the epicardium. Here, we have generated an inducible endothelial-specific Wt1 knockout mouse model (Wt1KOΔEC). Deletion of Wt1 in ECs during coronary plexus formation impaired coronary blood vessels and myocardium development. RNA-Seq analysis of coronary ECs from Wt1KOΔEC mice demonstrated that deletion of Wt1 exerted a major impact on the molecular signature of coronary ECs and modified the expression of several genes that are dynamically modulated over the course of coronary EC development. Many of these differentially expressed genes are involved in cell proliferation, migration and differentiation of coronary ECs; consequently, the aforementioned processes were affected in Wt1KOΔEC mice. The requirement of WT1 in coronary ECs goes beyond the initial formation of the coronary plexus, as its later deletion results in defects in coronary artery formation. Through the characterization of these Wt1KOΔEC mouse models, we show that the deletion of Wt1 in ECs disrupts physiological blood vessel formation.

Wt1 transcription factor impairs cardiomyocyte specification and drives a phenotypic switch from myocardium to epicardium.

During development, the heart grows by addition of progenitor cells to the poles of the primordial heart tube. In the zebrafish, Wilms tumor 1 transcription factor a (wt1a) and b (wt1b) genes are expressed in the pericardium, at the venous pole of the heart. From this pericardial layer, the proepicardium emerges. Proepicardial cells are subsequently transferred to the myocardial surface and form the epicardium, covering the myocardium. We found that while wt1a and wt1b expression is maintained in proepicardial cells, it is downregulated in pericardial cells that contributes cardiomyocytes to the developing heart. Sustained wt1b expression in cardiomyocytes reduced chromatin accessibility of specific genomic loci. Strikingly, a subset of wt1a- and wt1b-expressing cardiomyocytes changed their cell-adhesion properties, delaminated from the myocardium and upregulated epicardial gene expression. Thus, wt1a and wt1b act as a break for cardiomyocyte differentiation, and ectopic wt1a and wt1b expression in cardiomyocytes can lead to their transdifferentiation into epicardial-like cells.

P62 promotes FSH-induced antral follicle formation by directing degradation of ubiquitinated WT1.

In females, the pathophysiological mechanism of poor ovarian response (POR) is not fully understood. Considering the expression level of p62 was significantly reduced in the granulosa cells (GCs) of POR patients, this study focused on identifying the role of the selective autophagy receptor p62 in conducting the effect of follicle-stimulating hormone (FSH) on antral follicles (AFs) formation in female mice. The results showed that p62 in GCs was FSH responsive and that its level increased to a peak and then decreased time-dependently either in ovaries or in GCs after gonadotropin induction in vivo. GC-specific deletion of p62 resulted in subfertility, a significantly reduced number of AFs and irregular estrous cycles, which were same as pathophysiological symptom of POR. By conducting mass spectrum analysis, we found the ubiquitination of proteins was decreased, and autophagic flux was blocked in GCs. Specifically, the level of nonubiquitinated Wilms tumor 1 homolog (WT1), a transcription factor and negative controller of GC differentiation, increased steadily. Co-IP results showed that p62 deletion increased the level of ubiquitin-specific peptidase 5 (USP5), which blocked the ubiquitination of WT1. Furthermore, a joint analysis of RNA-seq and the spatial transcriptome sequencing data showed the expression of steroid metabolic genes and FSH receptors pivotal for GCs differentiation decreased unanimously. Accordingly, the accumulation of WT1 in GCs deficient of p62 decreased steroid hormone levels and reduced FSH responsiveness, while the availability of p62 in GCs simultaneously ensured the degradation of WT1 through the ubiquitin‒proteasome system and autophagolysosomal system. Therefore, p62 in GCs participates in GC differentiation and AF formation in FSH induction by dynamically controlling the degradation of WT1. The findings of the study contributes to further study the pathology of POR.

Transcription factor Wilms' tumor 1 regulates developmental RNAs through 3' UTR interaction.

Wilms' tumor 1 (WT1) is essential for the development and homeostasis of multiple mesodermal tissues. Despite evidence for post-transcriptional roles, no endogenous WT1 target RNAs exist. Using RNA immunoprecipitation and UV cross-linking, we show that WT1 binds preferentially to 3' untranslated regions (UTRs) of developmental targets. These target mRNAs are down-regulated upon WT1 depletion in cell culture and developing kidney mesenchyme. Wt1 deletion leads to rapid turnover of specific mRNAs. WT1 regulates reporter gene expression through interaction with 3' UTR-binding sites. Combining experimental and computational analyses, we propose that WT1 influences key developmental and disease processes in part through regulating mRNA turnover.

Inhibition of transcriptional coactivator YAP Impairs the expression and function of transcription factor WT1 in diabetic podocyte injury.

Podocyte injury and loss are hallmarks of diabetic nephropathy (DN). However, the molecular mechanisms underlying these phenomena remain poorly understood. YAP (Yes-associated protein) is an important transcriptional coactivator that binds with various other transcription factors, including the TEAD family members (nuclear effectors of the Hippo pathway), that regulate cell proliferation, differentiation, and apoptosis. The present study found an increase in YAP phosphorylation at S127 of YAP and a reduction of nuclear YAP localization in podocytes of diabetic mouse and human kidneys, suggesting dysregulation of YAP may play a role in diabetic podocyte injury. Tamoxifen-inducible podocyte-specific Yap gene knockout mice (YappodKO) exhibited accelerated and worsened diabetic kidney injury. YAP inactivation decreased transcription factor WT1 expression with subsequent reduction of Tead1 and other well-known targets of WT1 in diabetic podocytes. Thus, our study not only sheds light on the pathophysiological roles of the Hippo pathway in diabetic podocyte injury but may also lead to the development of new therapeutic strategies to prevent and/or treat DN by targeting the Hippo signaling pathway.

Upregulation of HOXA3 by isoform-specific Wilms tumour 1 drives chemotherapy resistance in acute myeloid leukaemia.

Upregulation of the Wilms' tumour 1 (WT1) gene is common in acute myeloid leukaemia (AML) and is associated with poor prognosis. WT1 generates 12 primary transcripts through different translation initiation sites and alternative splicing. The short WT1 transcripts express abundantly in primary leukaemia samples. We observed that overexpression of short WT1 transcripts lacking exon 5 with and without the KTS motif (sWT1+/- and sWT1-/-) led to reduced cell growth. However, only sWT1+/- overexpression resulted in decreased CD71 expression, G1 arrest, and cytarabine resistance. Primary AML patient cells with low CD71 expression exhibit resistance to cytarabine, suggesting that CD71 may serve as a potential biomarker for chemotherapy. RNAseq differential expressed gene analysis identified two transcription factors, HOXA3 and GATA2, that are specifically upregulated in sWT1+/- cells, whereas CDKN1A is upregulated in sWT1-/- cells. Overexpression of either HOXA3 or GATA2 reproduced the effects of sWT1+/-, including decreased cell growth, G1 arrest, reduced CD71 expression and cytarabine resistance. HOXA3 expression correlates with chemotherapy response and overall survival in NPM1 mutation-negative leukaemia specimens. Overexpression of HOXA3 leads to drug resistance against a broad spectrum of chemotherapeutic agents. Our results suggest that WT1 regulates cell proliferation and drug sensitivity in an isoform-specific manner.

The extracellular matrix protein agrin is essential for epicardial epithelial-to-mesenchymal transition during heart development.

During heart development, epicardial cells residing within the outer layer undergo epithelial-mesenchymal transition (EMT) and migrate into the underlying myocardium to support organ growth and morphogenesis. Disruption of epicardial EMT results in embryonic lethality, yet its regulation is poorly understood. Here, we report epicardial EMT within the mesothelial layer of the mouse embryonic heart at ultra-high resolution using scanning electron microscopy combined with immunofluorescence analyses. We identified morphologically active EMT regions that associated with key components of the extracellular matrix, including the basement membrane-associated proteoglycan agrin. Deletion of agrin resulted in impaired EMT and compromised development of the epicardium, accompanied by downregulation of Wilms' tumor 1. Agrin enhanced EMT in human embryonic stem cell-derived epicardial-like cells by decreasing ß-catenin and promoting pFAK localization at focal adhesions, and promoted the aggregation of dystroglycan within the Golgi apparatus in murine epicardial cells. Loss of agrin resulted in dispersal of dystroglycan in vivo, disrupting basement membrane integrity and impairing EMT. Our results provide new insights into the role of the extracellular matrix in heart development and implicate agrin as a crucial regulator of epicardial EMT.

Defective mesothelium and limited physical space are drivers of dysregulated lung development in a genetic model of congenital diaphragmatic hernia.

Congenital diaphragmatic hernia (CDH) is a developmental disorder associated with diaphragm defects and lung hypoplasia. The etiology of CDH is complex and its clinical presentation is variable. We investigated the role of the pulmonary mesothelium in dysregulated lung growth noted in the Wt1 knockout mouse model of CDH. Loss of WT1 leads to intrafetal effusions, altered lung growth, and branching defects prior to normal closure of the diaphragm. We found significant differences in key genes; however, when Wt1 null lungs were cultured ex vivo, growth and branching were indistinguishable from wild-type littermates. Micro-CT imaging of embryos in situ within the uterus revealed a near absence of space in the dorsal chest cavity, but no difference in total chest cavity volume in Wt1 null embryos, indicating a redistribution of pleural space. The altered space and normal ex vivo growth suggest that physical constraints are contributing to the CDH lung phenotype observed in this mouse model. These studies emphasize the importance of examining the mesothelium and chest cavity as a whole, rather than focusing on single organs in isolation to understand early CDH etiology.

EWSR1::WT1 Fusions in Neoplasms Other Than Conventional Desmoplastic Small Round Cell Tumor: Three Tumors Occurring Outside the Female Genital Tract.

Desmoplastic small round cell tumor (DSRCT) is a high-grade, primitive round cell sarcoma classically associated with prominent desmoplastic stroma, coexpression of keratin and desmin, and a characteristic EWSR1::WT1 gene fusion. DSRCT typically arises in the abdominopelvic cavity of young males with diffuse peritoneal spread and poor overall survival. Although originally considered to be pathognomonic for DSRCT, EWSR1::WT1 gene fusions have recently been detected in rare tumors lacking the characteristic morphologic and immunohistochemical features of DSRCT. Here, we report 3 additional cases of neoplasms other than conventional DSCRCT with EWSR1::WT1 gene fusions that occurred outside the female genital tract. Two occurred in the abdominopelvic cavities of a 27-year-old man and a 12-year-old girl, whereas the third arose in the axillary soft tissue of an 85-year-old man. All cases lacked prominent desmoplastic stroma and were instead solid and cystic with peripheral fibrous pseudocapsules and occasional intervening fibrous septa. Necrosis was either absent (1/3) or rare (2/3), and mitotic activity was low (<1 to 3 per 10 hpf). In immunohistochemical studies, there was expression of smooth muscle actin (3/3) and desmin (3/3), rare to focal reactivity for EMA (2/3), and variable expression of CK AE1/AE3 (1/3). Myogenin and MyoD1 were negative, and C-terminus-specific WT1 was positive in both cases tested (2/2). All 3 tumors followed a more indolent clinical course with 2 cases demonstrating no evidence of disease at 20 and 44 months after resection. The patient from case 3 died of other causes at 14 months with no evidence of recurrence. DNA methylation profiling showed that the 3 cases clustered with DSRCT; however, they demonstrated fewer copy number variations with 2 cases having a flat profile (0% copy number variation). Differential methylation analysis with hierarchical clustering further showed variation between the 3 cases and conventional DSRCT. Although further study is needed, our results, in addition to previous reports, suggest that EWSR1::WT1 gene fusions occur in rare and seemingly distinctive tumors other than conventional DSRCT with indolent behavior. Proper classification of these unusual soft tissue tumors with EWSR1::WT1 gene fusions requires direct correlation with tumor morphology and clinical behavior, which is essential to avoid overtreatment with aggressive chemotherapy.

Clinical utility of early rapid genome sequencing in the evaluation of patients with differences of sex development.

Establishing an early and accurate genetic diagnosis among patients with differences of sex development (DSD) is crucial in guiding the complex medical and psychosocial care they require. Genetic testing routinely utilized in clinical practice for this population is predicated upon physical exam findings and biochemical and endocrine profiling. This approach, however, is inefficient and unstandardized. Many patients with DSD, particularly those with 46,XY DSD, never receive a molecular genetic diagnosis. Rapid genome sequencing (rGS) is gaining momentum as a first-tier diagnostic instrument in the evaluation of patients with DSD given its ability to provide greater diagnostic yield and timely results. We present the case of a patient with nonbinary genitalia and systemic findings for whom rGS identified a novel variant of the WT1 gene and resulted in a molecular diagnosis within two weeks of life. This timeframe of diagnosis for syndromic DSD is largely unprecedented at our institution. Rapid GS expedited mobilization of a multidisciplinary medical team; enabled early understanding of clinical trajectory; informed planning of medical and surgical interventions; and guided individualized psychosocial support provided to the family. This case highlights the potential of early rGS in transforming the evaluation and care of patients with DSD.

WT1 gene mutations impact post-transplant relapse in myelodysplastic syndrome with excess blasts 2 patients.

Wilms tumor 1 (WT1) gene mutations are infrequent in myelodysplastic syndrome (MDS), but MDS with WT1 mutations (WT1mut) is considered high risk for acute myeloid leukemia (AML) transformation. The influence of WT1 mutations in patients with MDS after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is unclear. We performed a retrospective analysis of 136 MDS with excess blasts 2 (MDS-EB2) patients with available WT1 status who underwent their first allo-HSCT between 2017 and 2022 in our center. There were 20 (20/136, 15%) cases in the WT1mut group and 116 (116/136, 85%) cases in the WT1 wild-type (WT1wt) group. WT1mut patients had a higher 2-year cumulative incidence of relapse (CIR) than WT1wt cases (26.2% vs. 9.4%, p = 0.037) after allo-HSCT. Multivariate analysis of relapse showed that WT1 mutations (HR, 6.0; p = 0.002), TP53 mutations (HR, 4.2; p = 0.021), and ≥ 5% blasts in bone marrow (BM) at transplantation (HR, 6.6; p = 0.004) were independent risk factors for relapse. Patients were stratified into three groups according to the risk factors. Two-year CIR differed significantly in high-, intermediate-, and low-risk groups (31.8%, 11.6%, and 0%, respectively). Hence, WT1 mutations may be related to post-transplant relapse in patients with MDS-EB2, which warrants further study.

Overexpression of WT1 in all molecular subtypes of breast cancer and its impact on survival: exploring oncogenic and tumor suppressor roles of distinct WT1 isoforms.

BACKGROUND: Breast cancer is a highly heterogeneous solid tumor, posing challenges in developing targeted therapies effective for all mammary carcinoma subtypes. WT1 emerges as a promising target for breast cancer therapy due to its potential oncogenic role in various cancer types. Previous works have yielded inconsistent results. Therefore, further studies are needed to clarify the behavior of this complex gene in breast cancer. METHODS AND RESULTS: In this study, we examined WT1 expression in both Formalin Fixed Paraffin Embedded breast tumors (n = 41) and healthy adjacent tissues (n = 41) samples from newly diagnosed cases of ductal invasive breast cancer. The fold change in gene expression between the tumor and healthy tissue was determined by calculating 2-∆∆Ct. Disease-free survival analysis was computed using the Kaplan-Meier method. To identify the expression levels of different WT1 isoforms, we explored the ISOexpresso database. Relative quantification of the WT1 gene revealed an overexpression of WT1 in most cases. The percentage of patients surviving free of disease at 8 years of follow-up was lower in the group overexpressing WT1 compared to the group with down-regulated WT1. CONCLUSIONS: Interestingly, this overexpression was observed in all molecular subtypes of invasive breast cancer, underscoring the significance of WT1 as a potential target in all these subtypes. The observed WT1 down-expression in a few cases of invasive breast cancer, associated with better survival outcomes, may correspond to the down-regulation of a particular WT1-KTS (-) isoform: the WT1 A isoform (EX5-/KTS-). The co-expression of this WT1 oncogenic isoform with a regulated WT1- tumor suppressor isoform, such as the major WT1 F isoform (EX5-/KTS +), could also explain such survival outcomes. Due to its capacity to adopt dual roles, it becomes imperative to conduct individual molecular expression profiling of the WT1 gene. Such an approach holds great promise in the development of personalized treatment strategies for breast cancer.

WT1 and TP53 as valuable diagnostic biomarkers for relapse after hematopoietic stem cell transplantation in acute myeloid leukemia.

BACKGROUND: Relapse following hematopoietic stem cell transplantation (HSCT) occurs relatively frequently and is a significant risk factor for mortality in patients with acute myeloid leukemia (AML). Early diagnosis is, therefore, of utmost importance and can provide valuable guidance for appropriate and timely intervention. Here, the diagnostic value of two molecular markers, Wilms tumor 1 (WT1) and tumor suppressor protein p53 (TP53), were studied. METHODS AND RESULTS: Twenty AML patients undergoing HSCT participated in this investigation. Some had relapsed following HSCT, while others were in remission. Peripheral blood (PB) and bone marrow (BM) samples were collected following relapse and remission. WT1 and TP53 messenger RNA (mRNA) expression was evaluated using reverse transcription-quantitative polymerase chain reaction (RT‒qPCR). The diagnostic value of genes was evaluated by utilizing receiver-operating characteristic (ROC) curve analysis. ROC analysis showed WT1 and TP53 as diagnostic markers for relapse after HSCT in AML patients. The mRNA expression level of WT1 was elevated in individuals who experienced relapse compared to those in a state of remission (p value < 0.01). Conversely, the expression level of TP53 mRNA was lower in individuals who had relapsed compared to those in remission (p value < 0.01). CONCLUSIONS: WT1 and TP53 possess the potential to serve as invaluable biomarkers in the identification of molecular relapse after HSCT in patients with AML. Further studies for a definitive conclusion are recommended.

WT1-related disorders: more than Denys-Drash syndrome.

Historically, specific mutations in WT1 gene have been associated with distinct syndromes based on phenotypic characteristics, including Denys-Drash syndrome (DDS), Frasier syndrome (FS), Meacham syndrome, and WAGR syndrome. DDS is classically defined by the triad of steroid-resistant nephrotic syndrome (SRNS) onset in the first year of life, disorders of sex development (DSD), and a predisposition to Wilms tumor (WT). Currently, a paradigm shift acknowledges a diverse spectrum of presentations beyond traditional syndromic definitions. Consequently, the concept of WT1-related disorders becomes more precise. A genotype-phenotype correlation has been established, emphasizing that the location and type of WT1 mutations significantly influence the clinical presentation, the condition severity, and the chronology of patient manifestations. Individuals presenting with persistent proteinuria, with or without nephrotic syndrome, and varying degrees of kidney dysfunction accompanied by genital malformations should prompt suspicion of WT1 mutations. Recent genetic advances enable a more accurate estimation of malignancy risk in these patients, facilitating a conservative nephron-sparing surgery (NSS) approach in select cases, with a focus on preserving residual kidney function and delaying nephrectomies. Other key management strategies include kidney transplantation and addressing DSD and gonadoblastoma. In summary, recent genetic insights underscore the imperative to implement individualized, integrated, and multidisciplinary management strategies for WT1-related disorders. This approach is pivotal in optimizing patient outcomes and addressing the complexities associated with these diverse clinical manifestations.

WT1 exon 10 missense variant in a pediatric patient with focal segmental glomerulosclerosis with embryonal hyperplasia.

A 6-year-old boy was diagnosed with chromosomal abnormalities (48,XYY, + 21[11]/46,XY[19]) at 4 months of age after a physical examination revealed an undescended testis and a dwarf penis. He also had mild renal dysfunction and severe proteinuria, and kidney biopsy at 2 years of age revealed focal segmental glomerulosclerosis. Genetic analysis to investigate suspected WT1 gene abnormalities revealed a novel variant in NM_024426.6:exon10:c.1506 T > A (p.(Asp502Glu)). His kidney function deteriorated rapidly, leading to the induction of peritoneal dialysis at 5 years of age. Although this variant had not been previously reported, bilateral nephrectomy was performed to prevent any progression of the tumor. Histopathology showed all the glomeruli observed within the observation area to be completely sclerotic, while also showing evidence of embryonal hyperplasia. This case was not a hot spot for Denys-Drash syndrome, but it had a similar phenotype and pathology that could have been derived from a WT1 gene abnormality.

Myelodysplasia after clonal hematopoiesis with APOBEC3-mediated CYBB inactivation in retroviral gene therapy for X-CGD.

Stem cell gene therapy using the MFGS-gp91phox retroviral vector was performed on a 27-year-old patient with X-linked chronic granulomatous disease (X-CGD) in 2014. The patient's refractory infections were resolved, whereas the oxidase-positive neutrophils disappeared within 6 months. Thirty-two months after gene therapy, the patient developed myelodysplastic syndrome (MDS), and vector integration into the MECOM locus was identified in blast cells. The vector integration into MECOM was detectable in most myeloid cells at 12 months after gene therapy. However, the patient exhibited normal hematopoiesis until the onset of MDS, suggesting that MECOM transactivation contributed to clonal hematopoiesis, and the blast transformation likely arose after the acquisition of additional genetic lesions. In whole-genome sequencing, the biallelic loss of the WT1 tumor suppressor gene, which occurred immediately before tumorigenesis, was identified as a potential candidate genetic alteration. The provirus CYBB cDNA in the blasts contained 108 G-to-A mutations exclusively in the coding strand, suggesting the occurrence of APOBEC3-mediated hypermutations during the transduction of CD34-positive cells. A hypermutation-mediated loss of oxidase activity may have facilitated the survival and proliferation of the clone with MECOM transactivation. Our data provide valuable insights into the complex mechanisms underlying the development of leukemia in X-CGD gene therapy.

The potential mechanism of WT1-associated protein-induced N-6-methyladenosine modification of colony-stimulating factor 2 in the progression of oral squamous cell carcinoma by JAK/STAT3 pathway regulation.

Colony-stimulating factor 2 (CSF2) plays a regulatory role in numerous cancers. However, there is needed to investigate the role of CSF2 in oral squamous cell carcinoma (OSCC) malignant phenotype and the specific mechanisms of CSF2 N-6-methyladenosine (m6A) modification. Therefore, we investigated the regulatory mechanism of m6A-modified CSF2 by WT1-associated protein (WTAP) in OSCC via qRT-PCR, western blot, WTAP and CSF2 overexpression in OSCC. In a panel of OSCCs, Kaplan-Meier plot analysis indicated that high expression of CSF2 was associated with poorer prognosis. Cell functional experiments revealed that enrichment of CSF2 promoted the proliferation and migration of OSCC cells by activating the JAK/STAT3 pathway, whereas the reduced expression of CSF2 resulted in the malignant decline of OSCC cells by blocking the JAK/STAT3 pathway. This study also confirmed that WTAP enhanced the m6A level of CSF2 and facilitated the expression of CSF2 and that CSF2 silencing blocked the invasive phenotype of OSCC cells and reversed the malignancy induced by WTAP overexpression. Overall, this study demonstrated that WTAP mediates the m6A modification of CSF2 and the JAK/STAT3 pathway, which plays an oncogenic role in the development of OSCC and can be a target for the treatment of patients with OSCC.

Evaluation of pathogenicity of WT1 intron variants by in vitro splicing analysis.

BACKGROUND: Wilms tumor 1 (WT1; NM_024426) causes Denys-Drash syndrome, Frasier syndrome, or isolated focal segmental glomerulosclerosis. Several WT1 intron variants are pathogenic; however, the pathogenicity of some variants remains undefined. Whether a candidate variant detected in a patient is pathogenic is very important for determining the therapeutic options for the patient. METHODS: In this study, we evaluated the pathogenicity of WT1 gene intron variants with undetermined pathogenicity by comparing their splicing patterns with those of the wild-type using an in vitro splicing assay using minigenes. The three variants registered as likely disease-causing genes: Mut1 (c.1017-9 T > C(IVS5)), Mut2 (c.1355-28C > T(IVS8)), Mut3 (c.1447 + 1G > C(IVS9)), were included as subjects along the 34 splicing variants registered in the Human Gene Mutation Database (HGMD)®. RESULTS: The results showed no significant differences in splicing patterns between Mut1 or Mut2 and the wild-type; however, significant differences were observed in Mut3. CONCLUSION: We concluded that Mut1 and Mut2 do not possess pathogenicity although they were registered as likely pathogenic, whereas Mut3 exhibits pathogenicity. Our results suggest that the pathogenicity of intronic variants detected in patients should be carefully evaluated.