Zinc Finger Protein 521 Research Articles

Zinc finger protein 521 (ZNF521/Zfp521): Insights into its structure, function, regulation, and significance to cell differentiation

The zinc finger protein 521 (ZNF521) gene is located on human chromosome 18, specifically in the 18q11.2 region. As a zinc finger DNA-binding protein, ZNF521/Zfp521 acts as a transcription cofactor involved in the regulation of cell differentiation across various cell types, including hematopoietic, neural, and mesenchyme stem cells, B progenitor cells, preadipocytes, and osteoblasts. Its interactions with key proteins such as RUNX2, EBF1, SIAH2, or BMP2 further modulate these processes. In this review, we briefly summarize the current understanding of ZNF521/Zfp521, encompassing its structural, functional, post-translational modification, and cellular signaling pathways, especially its roles in cell differentiation and related diseases. In addition, we explore the process and effects of the interaction between Zfp521 and other proteins and discuss the molecular mechanisms of its roles in adipogenic, osteogenic, chondrogenic, and neural differentiation.

Zinc Finger 521 Modulates the Nrf2-Notch Signaling Pathway in Human Ovarian Carcinoma.

The human zinc finger protein 521 (ZNF521) is a co-transcriptional factor with multiple recognized regulatory functions in a range of normal, cancer and stem cell compartments. ZNF521 regulates proliferation, progression and CSC (cancer stem cell) compartments in human ovarian cancer (hOC), which is a very aggressive and late-diagnosed female tumor. Two other important regulators of hOC are the NRF2 and NOTCH signaling pathways. In the present paper, the mRNA and protein levels of ZNF521 were correlated with those of the NRF2-NOTCH signaling components in two different hOC cell lines and in a public dataset of 381 hOC patients. The data show that high levels of ZNF521 significantly increase NRF2-NOTCH signaling expression; conversely, the silencing of ZNF521 impairs NRF2-NOTCH signaling. This experimental work shows that, in hOC, different levels of ZNF521 modulate the NRF2-NOTCH signaling pathway and also influences hOC CSC properties.

ZNF521 Is Correlated with Tumor Immune Cell Infiltration and Act as a Valuable Prognostic Biomarker in Gastric Cancer.

Aim To explore the correlations between the expression of zinc finger protein 521 (ZNF521) with immune invasion and prognosis of gastric cancer. Methods Expression of ZNF521 was examined by immunohistochemistry in gastric cancer cases. Kaplan–Meier plotter was used to determine the relationships between ZNF521 and prognosis. TIMER and GEPIA were used to analyze the correlation between ZNF521 expression and gene markers of immune cell infiltration. Results The expression of ZNF521 was up-regulated in gastric cancer samples. Kaplan–Meier analysis indicated that higher expression of ZNF521 was associated with poor prognosis. The expression of ZNF521 was correlated with infiltrating levels of CD4+ T and CD8+ T cells, macrophages, neutrophils, and dendritic cells in gastric cancer, which also correlated with diverse immune marker sets. Conclusions ZNF521 is correlated significantly with immune cell infiltration and is a valuable biomarker for prognosis in gastric cancer.

Expression of the preadipocyte marker ZFP423 is dysregulated between well-differentiated and dedifferentiated liposarcoma

BackgroundWell-differentiated and dedifferentiated liposarcomas are rare soft tissue tumors originating in adipose tissue that share genetic abnormalities but have significantly different metastatic potential. Dedifferentiated liposarcoma (DDLPS) is highly aggressive and has an overall 5-year survival rate of 30% as compared to 90% for well-differentiated liposarcoma (WDLPS). This discrepancy may be connected to their potential to form adipocytes, where WDLPS is adipogenic but DDLPS is adipogenic-impaired. Normal adipogenesis requires Zinc Finger Protein 423 (ZFP423), a transcriptional coregulator of Perixosome Proliferator Activated Receptor gamma (PPARG2) mRNA expression that defines committed preadipocytes. Expression of ZFP423 in preadipocytes is promoted by Seven-In-Absentia Homolog 2 (SIAH2)-mediated degradation of Zinc Finger Protein 521 (ZFP521). This study investigated the potential role of ZFP423, SIAH2 and ZFP521 in the adipogenic potential of WDLPS and DDLPS.MethodsHuman WDLPS and DDLPS fresh and paraffin-embedded tissues were used to assess the gene and protein expression of proadipogenic regulators. In parallel, normal adipose tissue stromal cells along with WDLPS and DDLPS cell lines were cultured, genetically modified, and induced to undergo adipogenesis in vitro.ResultsImpaired adipogenic potential in DDLPS was associated with reduced ZFP423 protein levels in parallel with reduced PPARG2 expression, potentially involving regulation of ZFP521. SIAH2 protein levels did not define a clear distinction related to adipogenesis in these liposarcomas. However, in primary tumor specimens, SIAH2 mRNA was consistently upregulated in DDLPS compared to WDLPS when assayed by fluorescence in situ hybridization or real-time PCR.ConclusionsThese data provide novel insights into ZFP423 expression in adipogenic regulation between WDLPS and DDLPS adipocytic tumor development. The data also introduces SIAH2 mRNA levels as a possible molecular marker to distinguish between WDLPS and DDLPS.

ZNF521 which is downregulated by miR-802 suppresses malignant progression of Hepatocellular Carcinoma through regulating Runx2 expression

Zinc finger protein 521 (ZNF521) plays an important role in the tumor development and process. However, its regulatory role in hepatocellular carcinoma (HCC) remains unclear. In this study, we demonstrated for the first time that ZNF521 mRNA and protein was down-regulated in HCC tissues and cell lines. Down-regulated ZNF521 expression was significantly associated with malignant prognostic features, including advanced TNM stage and large tumor size. For 5-year survival, ZNF521 served as a potential prognostic marker of HCC patients. Moreover, ZNF521 inhibited cell proliferation, colony formation and cell viability through Runx2 transcriptional inhibition and AKT phosphorylation pathway. Moreover, we demonstrated that ZNF521 expression was regulated by miR-802. In HCC tissues. MiR-802 has an inverse correlation with ZNF521 expression. In conclusion, we demonstrate for the first time that ZNF521 is down-regulated in HCC tissues and inhibits HCC growth through Runx2 transcriptional inhibition and AKT inactivation, which was regulated by miR-802, suggesting the potential therapeutic value for HCC.

Identifying Potential Prognostic Markers for Muscle-Invasive Bladder Urothelial Carcinoma by Weighted Gene Co-Expression Network Analysis.

Muscle-invasive bladder urothelial carcinoma (MIBC) is characterized as a genetic heterogeneous cancer with a high percentage of recurrence and worse prognosis. Identify the prognostic potentials of novel genes for muscle-invasive urothelial bladder cancer could at least provide important information for early detection and clinical treatment. Weighted gene co-expression network analysis (WGCNA) algorithm, a powerful systems biology approach, was utilized to extract co-expressed gene networks from mRNA expression dataset to construct transcriptional modules in MIBC samples, which was associated with demographic and clinical traits of MIBC patients. The potential prognostic markers of MIBC were screened out in the discovery dataset and verified in an independent external validation dataset. A total of 8 co-expression modules were detected through the WGCNA algorithm in the discovery datasets based on 401 MIBC samples. One transcriptional module enriched in cell development was observed to be correlated with the MIBC prognosis in the discovery datasets (HR = 1.48, 95%CI = 1.04-2.11) and independently verified in an external dataset (HR = 3.59, 95%CI = 1.09-11.79). High expression of hub genes including discoidin domain receptor tyrosine kinase 2 (DDR2), PDZ and LIM domain 3 (PDLIM3), zinc finger protein 521 (ZNF521), methionine sulfoxide reductase B3 (MSRB3) were significantly associated with the unfavorable survival of MIBC patients. We identified and validated four novel potential biomarkers associated with prognosis of MIBC patients by constructing genes co-expression networks. The discovery of these genetic markers may provide a new target for the development of MIBC chemotherapeutic drugs.

Zinc Finger Protein 521 Regulates Early Hematopoiesis through Cell-Extrinsic Mechanisms in the Bone Marrow Microenvironment.

Zinc finger protein 521 (ZFP521), a DNA-binding protein containing 30 Krüppel-like zinc fingers, has been implicated in the differentiation of multiple cell types, including hematopoietic stem and progenitor cells (HSPC) and B lymphocytes. Here, we report a novel role for ZFP521 in regulating the earliest stages of hematopoiesis and lymphoid cell development via a cell-extrinsic mechanism. Mice with inactivated Zfp521 genes (Zfp521-/-) possess reduced frequencies and numbers of hematopoietic stem and progenitor cells, common lymphoid progenitors, and B and T cell precursors. Notably, ZFP521 deficiency changes bone marrow microenvironment cytokine levels and gene expression within resident HSPC, consistent with a skewing of hematopoiesis away from lymphopoiesis. These results advance our understanding of ZFP521's role in normal hematopoiesis, justifying further research to assess its potential as a target for cancer therapies.

ZNF521 sustains the differentiation block in MLL-rearranged acute myeloid leukemia.

Zinc finger protein 521 (ZNF521) is a multiple zinc finger transcription factor and a strong candidate as regulator of hematopoietic stem cell homeostasis. Recently, independent gene expression profile studies have evidenced a positive correlation between ZNF521 mRNA overexpression and MLL-rearranged acute myeloid leukemia (AML), leaving open the question on the role of ZNF521 in this subtype of leukemia. In this study, we sought to analyze the effect of ZNF521 depletion on MLL-rearranged AML cell lines and MLL-AF9 xenograft primary cells. Knockdown of ZNF521 with short-hairpin RNA (shRNA) led to decreased leukemia proliferation, reduced colony formation and caused cell cycle arrest in MLL-rearranged AML cell lines. Importantly, we showed that loss of ZNF521 substantially caused differentiation of both MLL-rearranged cell lines and primary cells. Moreover, gene profile analysis in ZNF521-silenced THP-1 cells revealed a loss of MLL-AF9-directed leukemic signature and an increase of the differentiation program. Finally, we determined that both MLL-AF9 and MLL-ENL fusion proteins directly interacted with ZNF521 promoter activating its transcription. In conclusion, our findings identify ZNF521 as a critical effector of MLL fusion proteins in blocking myeloid differentiation and highlight ZNF521 as a potential therapeutic target for this subtype of leukemia.

Computational Modeling of a Transcriptional Switch Underlying B-Lymphocyte Lineage Commitment of Hematopoietic Multipotent Cells.

Despite progresses in identifying the cellular mechanisms at the basis of the differentiation of hematopoietic stem/progenitor cells, little is known about the regulatory circuitry at the basis of lineage commitment of hematopoietic multipotent progenitors. To address this issue, we propose a computational approach to give further insights in the comprehension of this genetic mechanism. Differently from T lymphopoiesis, however, there is at present no mathematical model describing lineage restriction of multipotent progenitors to early B-cell precursors. Here, we provide a first model—constructed on the basis of current experimental evidence from literature and of publicly available microarray datasets—of the genetic regulatory network driving the cellular fate determination at the stage of lymphoid lineage commitment, with particular regard to the multipotent-B-cell progenitor transition. By applying multistability analysis methods, we are able to assess the capability of the model to capture the experimentally observed switch-like commitment behavior. These methods allow us to confirm the central role of zinc finger protein 521 (ZNF521) in this process, that we had previously reported, and to identify a novel putative functional interaction for ZNF521, which is essential to realize such characteristic behavior. Moreover, using the devised model, we are able to rigorously analyze the mechanisms underpinning irreversibility of the physiological commitment step and to devise a possible reprogramming strategy, based on the combined modification of the expression of ZNF521 and EBF1.

Genetic Contributions to Urgency Urinary Incontinence in Women

We identify genetic variants associated with urgency urinary incontinence in postmenopausal women. A 2-stage genome-wide association analysis was conducted to identify variants associated with urgency urinary incontinence. The WHI GARNET substudy with 4,894 genotyped post-reproductive white women was randomly split into independent discovery and replication cohorts. Genome-wide imputation was performed using IMPUTE2 with the 1000 Genomes ALL Phase I integrated variant set as a reference. Controls reported no urgency urinary incontinence at enrollment or followup. Cases reported monthly or greater urgency urinary incontinence and leaked sufficiently to wet/soak underpants/clothes. Logistic regression models were used to predict urgency urinary incontinence case vs control status based on genotype, assuming additive inheritance. Age, obesity, diabetes and depression were included in the models as covariates. Following quality control, 975,508 single nucleotide polymorphisms in 2,241 cases (discovery 1,102; replication 1,133) and 776 controls (discovery 405, replication 371) remained. Genotype imputation resulted in 9,077,347 single nucleotide polymorphisms and insertions/deletions with minor allele frequency greater than 0.01 available for analysis. Meta-analysis of the discovery and replication samples identified 6 loci on chromosomes 5, 10, 11, 12 and 18 associated with urgency urinary incontinence at p <10(-6). Of the loci 3 were within genes, the zinc finger protein 521 (ZFP521) gene on chromosome 18q11, the ADAMTS16 gene on chromosome 5p15 and the CIT gene on chromosome 12q24. The other 3 loci were intergenic. Although environmental factors also likely contribute, this first exploratory genome-wide association study for urgency urinary incontinence suggests that genetic variants in the ZFP521, CIT and ADAMTS16 genes might account for some of the observed heritability of the condition.

Abnormal Behaviors and Developmental Disorder of Hippocampus in Zinc Finger Protein 521 (ZFP521) Mutant Mice

Zinc finger protein 521 (ZFP521) regulates a number of cellular processes in a wide range of tissues, such as osteoblast formation and adipose commitment and differentiation. In the field of neurobiology, it is reported to be an essential factor for transition of epiblast stem cells into neural progenitors in vitro. However, the role of ZFP521 in the brain in vivo still remains elusive. To elucidate the role of ZFP521 in the mouse brain, we generated mice lacking exon 4 of the ZFP521 gene. The birth ratio of our ZFP521 Δ/Δ mice was consistent with Mendel's laws. Although ZFP521 Δ/Δ pups had no apparent defect in the body and were indistinguishable from ZFP521+/+ and ZFP521 +/Δ littermates at the time of birth, ZFP521 Δ/Δ mice displayed significant weight reduction as they grew, and most of them died before 10 weeks of age. They displayed abnormal behavior, such as hyper-locomotion, lower anxiety and impaired learning, which correspond to the symptoms of schizophrenia. The border of the granular cell layer of the dentate gyrus in the hippocampus of the mice was indistinct and granular neurons were reduced in number. Furthermore, Sox1-positive neural progenitor cells in the dentate gyrus and cerebellum were significantly reduced in number. Taken together, these findings indicate that ZFP521 directly or indirectly affects the formation of the neuronal cell layers of the dentate gyrus in the hippocampus, and thus ZFP521 Δ/Δ mice displayed schizophrenia-relevant symptoms. ZFP521 Δ/Δ mice may be a useful research tool as an animal model of schizophrenia.

Transcriptional Regulatory Cascades in Runx2-Dependent Bone Development

The development of the musculoskeletal system is a complex process that involves very precise control of bone formation and growth as well as remodeling during postnatal life. Although the understanding of the transcriptional mechanisms of osteogenesis has increased considerably, the molecular regulatory basis, especially the gene regulatory network of osteogenic differentiation, is still poorly understood. This review provides the reader with an overview of the key transcription factors that govern bone formation, highlighting their function and regulation linked to Runt-related transcription factor 2 (Runx2). Runx2 as the master transcription factor of osteoblast differentiation, Twist, Msh homeobox 2 (Msx2), and promyelocytic leukemia zinc-finger protein (PLZF) acting upstream of Runx2, Osterix (Osx) acting downstream of Runx2, and activating transcription factor 4 (ATF4) and zinc-finger protein 521 (ZFP521) acting as cofactors of Runx2 are discussed, and their relevance for tissue engineering is presented. References are provided for more in-depth personal study.

Regulation of B lymphopoiesis by Zinc Finger Protein 521 (ZFP521) (111.9)

Abstract The ZFP521 (Evi3/ZNF521/EHZF) transcription factor has been identified as an inhibitor of Early B cell factor 1 (EBF1), which is essential for B cell lineage specification and commitment. ZFP521 contains 30-zinc finger (ZF) domains, including C-terminal ZF’s that bind to EBF1. However, whether ZFP521 is required for appropriate B cell development and function has not been addressed. We demonstrated that Zfp521 transcripts correlate inversely with Ebf1 transcripts. Zfp521 transcripts are expressed at the highest levels in pre-pro-B and pro-B cells and decrease progressively with differentiation. In contrast, Ebf1 transcripts are detected only weakly in pre-pro-B cells and are increased at later stages in the bone marrow. In 3-wk old Zfp521 knockout (KO) mice, pre-pro-B and pro-B cells are increased substantially, while late pro-B, pre-B and immature B cells are reduced significantly. Re-circulating mature B cells accumulate prematurely in the bone marrow of Zfp521 KO mice relative to WT mice. We are addressing two possible models in these mice. ZFP521 may modulate EBF1 function through direct protein:protein interactions. Alternatively, because ZFP521 is itself a DNA-binding protein, ZFP521 may direct transcription of cognate target genes independently of EBF1. We obtained evidence that ZFP521 co-occupies functional promoters with EBF1 in pro-B cells. This indicates that ZFP521 regulates B cell development through interactions with EBF1 on target genes.

Zinc Finger Protein 521 (ZFP521) is required for the development of mast cells in mice (111.16)

Abstract Mast cells play crucial roles in both innate and adaptive immune responses. Evidence in our laboratory suggests that the ZFP521 (Evi3/ZNF521/EHZF) transcription factor orchestrates key pathways required for proper development and function of mast cells. ZFP521 is a nuclear protein that contains 30 zinc fingers. ZFP521 is important for the renewal and development of hematopoietic cells. Here, we demonstrate that ZFP521 is expressed highly in murine mast cells. To address the intrinsic roles of ZFP521 in mast cells, we developed a model system in which Zfp521 gene expression is ablated conditionally in mast cells of mice with floxed alleles (Zfp521 cKO mice) by mast cell-specific Cre (Mcpt5-Cre transgene). Zfp521 is required for normal numbers of mast cells in the peritoneal cavity (PMC). In part, the reduction of PMC may be due to the reduced expression of CD117 (c-Kit) on Zfp521 cKO-derived mast cells. Both CD117 and its ligand, Stem Cell Factor (SCF), are essential for mast cell development in the bone marrow. Additionally, the expression of several transcription factors, including GATA-1, GATA-2 and GATA-3, which regulate mast cell development and function is reduced in bone marrow-derived Zfp521 cKO mast cells. Together, our data provide insights into 1) a novel role for ZFP521 in hematopoiesis, and 2) the transcriptional regulatory network that governs the development and function of mast cells.

The Role of Zinc Finger Protein 521/Early Hematopoietic Zinc Finger Protein in Erythroid Cell Differentiation

ZNF521 (zinc finger protein 521) is a transcription factor with an N-terminal transcriptional repressor motif and 30 zinc finger domains. Although a high expression level of ZNF521 in human CD34+ progenitors and hematopoietic malignancies has been demonstrated, the functional role of ZNF521 in hematopoietic cell differentiation has not been clarified. In this study, we analyzed the role of ZNF521 in erythroid cell differentiation using the short hairpin RNA (shRNA)-mediated gene silencing method. Down-regulation of ZNF521 mediated by transient expression of shRNA for ZNF521 resulted in increased synthesis of hemoglobin in K562 and HEL cell lines as compared with control cells. K562-derived clones in which ZNF521 was constitutively silenced by shRNA also showed marked synthesis of hemoglobin and an increased expression level of glycophorin A. Since GATA-1 is the key regulator of erythroid differentiation, the effect of ZNF521 on transcription activity of GATA-1 was analyzed using a luciferase assay. GATA-1 activity was markedly inhibited by ZNF521 in a dose-dependent manner. Deletion analysis of ZNF521 showed that the repressive effect requires an N-terminal repression motif. Furthermore, the direct interaction of ZNF521 with GATA-1 was demonstrated. These results indicate that ZNF521 modulates erythroid cell differentiation through direct binding with GATA-1.