WTAP is a promising diagnosis and treatment biomarker that inhibits the proliferation and invasion of melanoma cells.

Background: Hepatocellular carcinoma (HCC) is a primary aggressive gastrointestinal neoplasm that affects patients worldwide. It has been shown that Wilms' tumor 1-associating protein (WTAP) is frequently upregulated in various cancers. However, the potential role of WTAP in HCC remains largely unknown.Methods: The expression levels of WTAP in human HCC tissues were determined by the western blotting and immunohistochemical (IHC) staining. A correlation between the WTAP expression, clinicopathological features, and the HCC prognosis was analyzed. The WTAP expression was silenced by short hairpin RNA (shRNA), and effects of the knockdown of WTAP on the proliferation and invasion of HCC cells were assessed. The microRNAs (miRNAs) involved in the regulation of the WTAP expression were identified by a bioinformatics analysis and further confirmed by in vitro assays.Results: The expression levels of WTAP in liver cancer tissues were significantly elevated and compared with those in the adjacent normal tissues and significantly correlated with the clinical stage and prognosis in patients with HCC. Further investigation revealed that the knockdown of WTAP drastically suppressed HCC cell proliferation and invasion abilities. Luciferase reporter assay and validation experiments confirmed that WTAP was a direct target of miR-139-5p. Moreover, the overexpression of WTAP could partly abolish the inhibitory effects of miR-139-5p on the HCC cell growth and invasion. Mechanistically, we revealed that the miR-139-5p/WTAP axis regulated the HCC progression by controlling the epithelial to mesenchymal transition (EMT).Conclusions: In summary, the results indicate that WTAP is a potential oncogene in HCC and miR-139-5p negatively regulates the WTAP expression. MiR-139-5p/WTAP can be utilized as a potential therapeutic target for HCC.

Acute myeloid leukemia (AML) is a heterogenous disease and the survival of AML patients is largely attributed to the improvement of supportive treatment. Wilms' tumor 1-associated protein (WTAP) is a nuclear protein functions in many physiological and pathological processes. Although its expression and function in many malignant diseases have been reported, its prognostic and epigenetic roles in AML are largely unknown. Peripheral blood or bone marrow samples were collected from AML patients. The WTAP expression was detected by western blot. WTAP expression level and patients clinical features were analyzed using statistical methods. WTAP knockdown AML cells were constructed. The experiments on proliferation, tumorigenic ability, cell cycle, and apoptosis were performed. Transcriptome sequencing was performed and analyzed. M6A methylation level was measured and m6A-RIP was performed to quantify m6A methylation level of MYC mRNA. RNA stability assay was performed to measure the half-life of mRNA. WTAP was overexpressed in AML patients and was an independent poor-risk factor in AML (p = 0.0140). Moreover, we found that WTAP regulated proliferation, tumorigenesis, cell cycle, and differentiation of AML cells. Furthermore, WTAP made AML cells resistant to daunorubicin. In further investigations, m6A methylation level was downregulated when knocking down WTAP, and c-Myc was upregulated due to the decreased m6A methylation of MYC mRNA. High WTAP expression predicts poor prognosis in AML and WTAP plays an epigenetic role in AML.

This study aimed to analyze the functional roles and molecular mechanism of Wilms' tumor 1-associating protein (WTAP) in the tumorigenesis of nonsmall-cell lung cancer (NSCLC). Retrospective analysis was used. Tumor tissues and surrounding nontumor tissues of 150 patients with NSCLS who were surgically resected in the Fourth Hospital of Hebei Medical University from January 2016 to January 2018 were selected. The expression of WTAP in NSCLC tissues was detected by immunohistochemistry. Clinicopathologic parameters were then subjected to univariate and multivariate Cox regression analysis in purpose of uncovering the independent risk factors for overall survival time. MTS (3-[4,5-dimethylthiazol-zyl]-5-[3-carboxymethoxyphenyl]-2-[4-sulfophenyl]-2H-tetrazoliuzolium, inner salt) assay, colony formation assay, and transwell assays were performed to estimate cell proliferation, migration, and invasion. Meanwhile, the relationship between WTAP and the cell migration and invasion marker-related proteins were evaluated by Western blot analysis and RT-qPCR. WTAP expression was knocked-down in cell lines by shRNA, and RNA-Seq was performed to investigate the pathways regulated by WTAP. In NSCLC patients, WTAP was highly expressed in tumor tissues and the higher expression was significantly associated with poor overall survival (OS) ( P <0.01). Compared with the control group in vitro, the overexpression of WTAP could significantly promote cell proliferation, migration, and invasion ( P <0.01), while knock-down WTAP significantly reduces the above effects ( P <0.01). In a mouse orthotopic implantation model, higher WTAP abundance could significantly promote tumor enlargement compared with the control group ( P <0.01). Compared with the control group, the knock-down of WTAP significantly inhibit the expression of carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) in cell lines ( P <0.01). Besides, in NSCLC, knocked-down CEACAM5 significantly reduced the impact of WTAP on cell proliferation, migration, and invasion compared with the control group ( P <0.05). This study suggests that high expression of WTAP was associated with poor clinical outcomes. CEACAM5 may play a synergistic role with WTAP to jointly promote NSCLC progression by enhancing cell proliferation, invasion, and migration.

Apoptosis of vascular smooth muscle cells (SMC) is a culprit event in atherosclerotic plaque destabilization. We recently discovered that Wilms’ tumor 1-associating protein (WTAP) is a dynamically expressed transcriptional regulator that can be pro-apoptotic for human SMCs (Circ Res, 2006). To identify upstream regulators of this nuclear protein, we screened growth factors for their capacity to impact WTAP expression and found that insulin-like growth factor-1 (IGF-1), a potent survival factor for SMCs, stimulated a striking decline in WTAP protein abundance, to 10% at 12 h. We further determined that this decline in WTAP was due specifically to WTAP protein degradation, established by pulse-chase analysis of 35 S-labeled WTAP and the absence of an acute effect of IGF-1 on WTAP mRNA abundance. IGF-1-mediated WTAP degradation was blocked by two mechanistically distinct IGF-1 receptor inhibitors (picropodophyllin and PQ401) and by inhibition of phosphatidylinositol 3 (PI3)-kinase but not by MEK inhibition. In addition, IGF-1 induced the association of WTAP with ubiquitin, established by coimmunoprecipitation, and the downregulation of WTAP by IGF-1 was abrogated by inhibiting 26S proteasome activity with lactacystin or MG132. Interestingly, IGF-1 also stimulated phosphorylation of WTAP, that preceded the association of WTAP with ubiquitin, and hyperphosphorylation of WTAP through phosphatase-inhibition further accelerated WTAP degradation. Finally, to determine if WTAP downregulation was necessary for IGF-1-mediated SMC survival, surface expression of phosphatidylserine was quantified by flow cytometry of SMCs infected with retrovirus containing WTAP cDNA. Whereas IGF-1 enhanced the survival of vector-infected SMCs this was completely abrogated in WTAP-overexpressing SMCs. Conclusions: IGF-1-mediated SMC survival is dependent on the rapid depletion of WTAP from the nucleus, a degradation cascade that is heralded by WTAP phosphorylation. This WTAP phosphorylation and clearance response represents a novel consequence of PI3-kinase activation and highlights WTAP as a key negative regulator of SMC survival during vascular remodeling.

Castration-resistant prostate cancer (CRPC) is one of the most prevalent cancers in men. The new generation androgen receptor (AR) inhibitor enzalutamide can improve the therapeutic effectiveness of patients with CRPC. However, these patients eventually develop acquired enzalutamide resistance (ENZR), and the mechanisms underlying resistance are not well understood. Wilms' tumor 1-associating protein (WTAP) plays an important role in m6A modification and has been reported as an oncogene in various cancers. Here, we utilized a tissue microarray and collected tissues from prostate cancer (PCa) patients to detect WTAP expression, and found that WTAP is upregulated in PCa. Meanwhile, WTAP overexpression promotes cell proliferation and accelerates tumor growth through colony formation assays and the establishment of a subcutaneous xenograft model in vivo. These findings establish the tumor promoter role of WTAP in prostatic tumorigenesis. Furthermore, we verified that WTAP is a novel responsive gene of AR via promoter activity and chromatin immunoprecipitation (ChIP) assays. Importantly, we uncovered that WTAP is upregulated in ENZR cells, and WTAP knockdown inhibited the proliferation of ENZR cells. Mechanistically, ubiquitin-specific protease (USP7) enhanced the stability of WTAP by the ubiquitin-proteasome pathway in ENZR cells, thereby WTAP increases promote AKT signaling through an m6A-mediated way, and an AKT inhibitor can abolish the pro-resistance phenotype mediated by WTAP. Together, these findings suggest that WTAP plays a key role in ENZR development of PCa cells, and WTAP may be a potential treatment target for ENZR tumors. In this manuscript, we utilized a tissue microarray and collected tissues from prostate cancer (PCa) patients to detect WTAP expression, and found that WTAP is upregulated in PCa. Meanwhile, WTAP overexpression promotes cell proliferation and accelerates tumor growth through colony formation assays and the establishment of a subcutaneous xenograft model in vivo. These findings establish the tumor promoter role of WTAP in prostatic tumorigenesis. Furthermore, we verified that WTAP is a novel responsive gene of AR via promoter activity and chromatin immunoprecipitation (ChIP) assays. Importantly, we uncovered that WTAP is upregulated in ENZR cells, and WTAP knockdown inhibited the proliferation of ENZR cells. Mechanistically, ubiquitin-specific protease (USP7) enhanced the stability of WTAP by the ubiquitin-proteasome pathway in ENZR cells, thereby WTAP increases promote AKT signaling through an m6A-mediated way, and an AKT inhibitor can abolish the pro-resistance phenotype mediated by WTAP. Together, these findings suggest that WTAP plays a key role in ENZR development of PCa cells, and WTAP may be a potential treatment target for ENZR tumors.

Wilms' tumor 1-associating protein (WTAP) interacts with the Wilms' tumor 1 gene. Although originally classified as a tumor suppressor, WTAP was later found to be over-expressed in glioblastoma which is regarded as a grade IV astrocytoma. However, the expression in other glioma grades and the relationship between WTAP expression and the prognosis of glioma patients are still unknown. In this study, we investigated WTAP expression in 169 different types of glioma cases using western blot analysis and immunohistochemistry assay. Further, we evaluated the association of WTAP expression with clinicopathological characteristics using chi-square test and Spearman's correlation test. We used univariate and multivariate Cox regression analyses to evaluate the independency of diferent WTAP expression. Then, the survival curves were calculated using the Kaplan-Meier method. Results showed that WTAP was over-expressed in glioma tissues, and the expression was closely correlated with glioma grade. Moreover, high WTAP expression was correlated with poor postoperative survival in glioma patients. WTAP may serve as a novel prognostic marker.

Wilms' tumor 1-associated protein (WTAP), a component of the m6A methyltransferase complex, recruits the m6A methyltransferases METTL3 and METTL14 to the corresponding mRNA targets to participate in the formation of N6-methyladenosine. However, the molecular mechanism of WTAP in the tumorigenesis and progression of nasopharyngeal carcinoma (NPC) remains unclear. This study aimed to explore the prognostic value and biological function of WTAP in NPC. We assessed WTAP expression and its prognostic significance using microarray datasets from the Gene Expression Omnibus (GSE12452) database and 100 NPC tissues via bioinformatics analysis and immunohistochemistry (IHC), respectively. Moreover, gene ontology (GO) and gene set enrichment analysis (GSEA) were performed. In addition, the correlation of WTAP expression with the expression of immune cell biomarkers was analyzed. The results showed that WTAP expression was significantly overexpressed in NPC tissues in GSE12452. The overexpression of WTAP was validated by the external datasets including NPC tissues (GSE150430) and NPC cell lines (GSE39826). GO analysis suggested enrichment in the nucleoplasm (cellular component) and cell cycle (biological process). The GSEA revealed that differentially expressed genes were enriched in E2F-targets, Myc_targets_v1, G2M checkpoint, Myc_targets_v2, and Interferon-alpha-response. In IHC analysis, WTAP was upregulated in NPC tissues, and high levels of WTAP expression were significantly correlated with the advanced T stage (p=0.047) and advanced N stage (p=0.018). Cox regression demonstrated that WTAP overexpression was an independent biomarker of poor prognosis for overall survival (hazard ratio [HR], 4.747; 95% confidence interval [CI], 1.671-13.482; p=0.003). In IHC analysis, the expression of WTAP was positively correlated with CD206 (biomarker for M2 macrophages) (p=0.018) but negatively correlated with CD8a (biomarker for cytotoxic T cells) (p=0.001). In conclusion, WTAP is a promising prognostic biomarker and may participate in the regulation of immune cell infiltration in NPC.

Background: Wilms tumor 1-associated protein (WTAP) plays a critical role in ribonucleic acid (RNA) methylation of N6 adenosine (m6A) modification, which is closely related with varieties of biological process. However, the role of WTAP in cancers remains to be determined. This study is designed to demonstrate the prognostic landscape of WTAP in pan-cancer and explore the relationship between WTAP expression and immune infiltration.Methods: Here, we investigated the expression level and prognostic role of WTAP in pan-cancer using multiple databases, including PrognoScan, GEPIA, and Kaplan-Meier Plotter. Then, applying the GEPIA and TIMER databases, we illustrated the correlations between WTAP expression and immune infiltration in tumors, especially liver hepatocellular carcinoma (LIHC), and esophageal carcinoma (ESCA).Results: WTAP had significant higher expression levels in tumor tissues of ESCA, LIHC, etc., while lower expression levels in those of bladder urothelial carcinoma (BLCA), breast invasive carcinoma (BRCA), etc. And WTAP demonstrated multifaceted prognostic value in cancers. Of our interests, WTAP exerted a harmful effect on LIHC patient for overall survival (OS) and progression free survival (PFS). WTAP expression also significantly associated with the infiltration levels of B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells (DC) in LIHC but not ESCA. Furthermore, combined analysis about WTAP expression level and immune cell specific gene markers implied WTAP correlates with regulatory cells (T reg) infiltration in LIHC and ESCA.Conclusion: The m6A regulator WTAP can serve as a prognostic biomarker for certain tumor types in pan-cancer and potentially result from immune cell infiltration.

Multiple myeloma (MM) remains incurable, largely owing to the lack of effective therapeutic targets. Wilms’ tumor 1-associated protein (WTAP) has been implicated in MM tumorigenesis, but its underlying molecular mechanisms remain unclear. This study aimed to elucidate the role of WTAP in MM progression. Bone marrow samples from newly diagnosed MM patients were analyzed. WTAP expression was assessed via Quantitative real-time PCR (qRT-PCR) and Western blot. Cell proliferation was evaluated using EdU and flow cytometry assays, while RNA immunoprecipitation (RIP) confirmed protein interactions. WTAP was overexpressed in MM patients and correlated with poor survival. Its knockdown significantly suppressed MM cell proliferation and inflammation. RIP assays identified MAP6D1 as a potential WTAP target. RNA-seq analysis suggested WTAP regulates MM proliferation via the Hippo signaling pathway. WTAP promotes MM proliferation by targeting MAP6D1 and modulating the Hippo pathway, highlighting its potential as a therapeutic target.

Few reports exist regarding the expression and function of Wilms’ tumor 1-associated protein (WTAP) in colorectal cancer (CRC), and the evidence is controversial. Our analysis explored the expression of WTAP in CRC tissue, and analyzed its clinical and prognostic significance. WTAP expression was significantly higher in CRC tissue than in colorectal adenoma and normal colorectal tissue. WTAP was highest in left colon tumor samples and negatively associated with tumor differentiation, as well as depth of tumor invasion. In multiple logistic regression analysis, independent predictors of WTAP expression in CRC included tumor in the left colon (odds ratio = 2.634; 95% confidence interval: 1.129–6.142; P = 0.025) and poorly differentiated tissue (0.072; 0.014–0.367; P = 0.002). No clear relationship was observed between CRC patient prognosis and WTAP expression. We suggest that WTAP expression is upregulated in CRC, highly expressed in left colon cancer and negatively correlated with tumor differentiation.

EBV downregulates the m6A “writer” WTAP in EBV-associated gastric carcinoma

Wilms' tumor 1-associating protein (WTAP), a core component of the N6-methyladenosine (m6A) methyltransferase complex, plays a crucial role in various biological processes. However, functional studies of WTAP in atherosclerosis development are largely unknown. Here, we demonstrate that WTAP expression was elevated in lipopolysaccharide (LPS)-stimulated macrophages and atherosclerotic lesions of apolipoprotein E-deficient (ApoE-/-) mice. To explore its functional role, we employed AAV8-mediated invivo knockdown and siRNA-mediated invitro silencing, which revealed that WTAP deficiency attenuated macrophage apoptosis and reduced atherosclerotic plaque formation. Mechanistically, we identified myosin heavy chain 11 (MYH11) as a mediator of WTAP-induced macrophage apoptosis. Notably, WTAP upregulated MYH11 expression in macrophages through an m6A-independent mechanism. These results delineate a new molecular paradigm that macrophage WTAP promotes macrophage apoptosis and atherosclerosis by increasing MYH11 expression, indicating that WTAP may be a potential therapeutic target against atherosclerosis.

N6-methyladenosine modification, especially Wilms tumor 1-associated protein (WTAP), is reportedly associated with a variety of cancers, including colorectal cancer (CRC). Angiogenesis also plays an important role in the occurrence and development of CRC. However, only a few studies have reported the biological mechanisms underlying this connection. Therefore, tissue microarray and public database were used to explore WTAP levels in CRC. Then, WTAP was down-regulated and over-expressed, respectively. CCK8, EdU, colony formation, and transwell experiments were performed to study the role of WTAP in CRC. Combined RNA sequencing and m6A RNA immunoprecipitation (MeRIP) sequencing, we found downstream molecules VEGFA. Moreover, a tube formation assay was executed for tumor angiogenesis. Finally, a subcutaneous tumorigenesis assay in nude mice was used to examine the tumor-promoting effect of WTAP in vivo. In the present study, WTAP was significantly upregulated in CRC cells and patients with CRC. Moreover, higher WTAP expression was observed in the TCGA and CPATC databases in CRC tissues. WTAP over-expression exacerbates cell proliferation, migration, invasion, and angiogenesis. Conversely, WTAP knockdown inhibited the malignant biological behavior of CRC cells. Mechanistically, WTAP positively regulated VEGFA, as identified using RNA sequencing and MeRIP sequencing. Moreover, we identified YTHDC1 as a downstream effector of the YTHDC1-VEGFA axis in CRC. Furthermore, increased WTAP expression activated the MAPK signaling pathway, which led to enhanced angiogenesis. In conclusion, our study revealed that the WTAP/YTHDC1/VEGFA axis promotes CRC development, especially angiogenesis, suggesting that it may act as a potential biomarker of CRC.

Diagnostic value and immune infiltration characterization of WTAP as a critical m6A regulator in liver transplantation.

WTAP (Wilms tumor 1-associating protein) is a recently identified nuclear protein that is essential for mouse embryo development. The Drosophila homolog of WTAP, Fl(2)d, regulates pre-mRNA splicing; however, the role of WTAP in mammalian cells is uncertain. To elucidate a context for WTAP action, we screened growth and survival factors for their effects on WTAP expression in vascular smooth muscle cells (SMCs), a cell type previously found to express WTAP dynamically. This revealed that insulin-like growth factor-1 (IGF-1) uniquely reduced WTAP abundance. This decline in WTAP proved to be necessary for IGF-1 to confer its antiapoptotic properties, which were blocked by transducing the WTAP gene into SMCs. WTAP down-regulation by IGF-1 was mediated by an IGF-1 receptor-phosphatidylinositol 3-kinase-Akt signaling axis that directed WTAP degradation via a nuclear 26 S proteasome. Moreover, by promoting the degradation of WTAP, IGF-1 shifted the pre-mRNA splicing program for the survival factor, survivin, to reduce expression of survivin-2B, which is proapoptotic, and increase expression of survivin, which is antiapoptotic. Knockdown of survivin-2B rescued the ability of IGF-1 to promote survival when WTAP was overexpressed. These data uncover a novel regulatory cascade for human SMC survival based on adjusting the nuclear abundance of WTAP to define the splice variant balance among survivin isoforms.