Cited2 is a key regulator of placental development and plasticity.

The biology of trophoblast cell lineage development and placentation is characterized by the involvement of several known transcription factors. Central to the action of a subset of these transcriptional regulators is CBP-p300 interacting transactivator with Glu/Asp-rich carboxy-terminal domain 2 (CITED2). CITED2 acts as a coregulator modulating transcription factor activities and affecting placental development and adaptations to physiological stressors. These actions of CITED2 on the trophoblast cell lineage and placentation are conserved across the mouse, rat, and human. Thus, aspects of CITED2 biology in hemochorial placentation can be effectively modeled in the mouse and rat. In this review, we present information on the conserved role of CITED2 in the biology of placentation and discuss the use of CITED2 as a tool to discover new insights into regulatory mechanisms controlling placental development.

Transcriptional mechanism of E2F1/TFAP2C/NRF1 in regulating KANK2 gene in nephrotic syndrome.

The mortality rate linked with nephrotic syndrome (NS) is quite high. The renal tubular injury influences the response of NS patients to steroid treatment. KN motif and ankyrin repeat domains 2 (KANK2) regulates actin polymerization, which is required for renal tubular cells to maintain their function. In this study, we found that the levels of KANK2 in patients with NS were considerably lower than those in healthy controls, especially in NS patients with acute kidney injury (AKI). To get a deeper understanding of the KANK2 transcriptional control mechanism, the core promoter region of the KANK2 gene was identified. KANK2 was further found to be positively regulated by E2F Transcription Factor 1 (E2F1), Transcription Factor AP-2 Gamma (TFAP2C), and Nuclear Respiratory Factor 1 (NRF1), both at mRNA and protein levels. Knocking down E2F1, TFAP2C, or NRF1 deformed the cytoskeleton of renal tubular cells and reduced F-actin content. EMSA and ChIP assays confirmed that all three transcription factors could bind to the upstream promoter transcription site of KANK2 to transactivate KANK2 in renal tubular epithelial cells. Our study suggests that E2F1, TFAP2C, and NRF1 play essential roles in regulating the KANK2 transcription, therefore shedding fresh light on the development of putative therapeutic options for the treatment of NS patients.

TFAP2C inhibits cell autophagy to alleviate myocardial ischemia/reperfusion injury by regulating miR-23a-5p/SFRP5/Wnt5a axis.

Myocardial ischemia/reperfusion (MI/R) injury contributes to severe injury for cardiomyocytes. In this study, we aimed to explore the underlying mechanism of TFAP2C on cell autophagy in MI/R injury. MTT assay measured cell viability. The cells injury was evaluated by commercial kits. IF detected the level of LC3B. Dual luciferase reporter gene assay, ChIP or RIP assay were performed to verify the interactions between crucial molecules. We found that TFAP2C and SFRP5 expression were decreased while miR-23a-5p and Wnt5a increased in AC16 cells in response to H/R condition. H/R induction led to cell injury and induced autophagy, which were reversed by TFAP2C overexpression or 3-MA treatment (an autophagy inhibitor). Mechanistically, TFAP2C suppressed miR-23a expression through binding to miR-23a promoter, and SFRP5 was a target gene of miR-23a-5p. Moreover, miR-23a-5p overexpression or rapamycin reversed the protective impacts of TFAP2C overexpression on cells injury and autophagy upon H/R condition. In conclusion, TFAP2C inhibited autophagy to improve H/R-induced cells injury by mediating miR-23a-5p/SFRP5/Wnt5a axis.

Oncogenic LINC00857 recruits TFAP2C to elevate FAT1 expression in gastric cancer.

FAT atypical cadherin 1 (FAT1) is a mutant gene frequently found in human cancers and mainly accumulates at the plasma membrane of cancer cells. Emerging evidence has implicated FAT1 in the progression of gastric cancer (GC). This study intended to identify a regulatory network related to FAT1 in GC development. Upregulated expression of FAT1 was confirmed in GC tissues, and silencing FAT1 was observed to result in suppression of GC cell oncogenic phenotypes. Mechanistic investigation results demonstrated that FAT1 upregulated AP-1 expression by phosphorylating c-JUN and c-FOS, whereas LINC00857 elevated the expression of FAT1 by recruiting a transcription factor TFAP2C. Functional experiments further suggested that LINC00857 enhanced the malignant biological characteristics of GC cells through TFAP2C-mediated promotion of FAT1. More importantly, LINC00857 silencing delayed the tumor growth and blocked epithelial-mesenchymal transition in tumor-bearing mice, which was associated with downregulated expression of TFAP2C/FAT1. To conclude, LINC00857 plays an oncogenic role in GC through regulating the TFAP2C/FAT1/AP-1 axis. Therefore, this study contributes to extended the understanding of gastric carcinogenesis and LINC00857 may serve as a therapeutic target for GC.

KLF14/miR-1283/TFAP2C axis inhibits HER2-positive breast cancer progression via declining tumor cell proliferation.

MiR-1283 has been identified as a tumor suppressor in some malignancies. Whereas, the role of miR-1283 in HER2-positive (HER2+) breast cancer, particularly its role in regulating cell proliferation, one of the most significant features of tumor progression, is unclear. The related microRNA screened by the breast cancer sample GSE131599 dataset were detected in HER2+ breast cancer tissues and cell lines. Then, the obtained miR-1283 was overexpressed in SKBR3 and BT-474 cells followed by relevant functional assays concerning cell proliferation and apoptosis. The xenograft mouse model was induced and the effect of miR-1283 on tumor growth and cell proliferation was examined. The target of miR-1283 and the transcription factor regulating miR-1283 were predicted and identified. Finally, the influence of transcription factor KLF14 on cell proliferation and apoptosis was investigated. An integrated analysis confirmed that miR-1283 expression was significantly decreased in HER2+ breast cancer tissues. Also, by q-RT-PCR detection, miR-1283 expression was markedly reduced in HER2+ breast cancer tissues and cell lines. The miR-1283 overexpression prevented the proliferation and enhanced apoptosis of HER2+ breast cancer cells, as well as inhibited tumor growth. Mechanistically, miR-1283 inhibited TFAP2C expression by targeting the 3'-untranslated regions of TFAP2C messenger RNA, and the KLF14 enhanced miR-1283 level via binding to its promoter. The result subsequently confirmed the KLF14/miR-1283 signaling suppressed cell proliferation in HER2+ breast cancer. Our results suggested that the KLF14/miR-1283/TFAP2C axis inhibited HER2+ breast cancer progression, which might provide novel insight into mechanical exploration for this disease.

Transcription factor AP-2 gamma affects porcine early embryo development by regulating epigenetic modification.

RESEARCH QUESTION: What is the role and mechanism of action of transcription factor AP-2 gamma (TFAP2C) in porcine early embryo development? DESIGN: TFAP2C siRNA were injected into porcine oocytes, which subsequently underwent IVF. Different stages of embryos were collected for RNA sequencing, quantitative polymerase chain reaction, immunofluorescence staining to explore the affects in gene expression and epigenetic modification. Porcine fetal fibroblasts were transfected with siRNA, and cells were collected for chromatin immunoprecipitation and dual luciferase reporter assays. RESULTS: The deficiency of TFAP2C led to disorders in early embryonic development; 1208 genes were downregulated and 792 genes were upregulated in TFAP2C knockdown (TFAP2C-KD) embryos. The expression of epigenetic modification enzymes KDM5B, SETD2 were significantly elevated in the TFAP2C-KD group (P < 0.001). Meanwhile, the modification levels of H3K4me3 and H3K4me2 were significantly decreased (P = 0.0021, P = 0.0029), and H3K36me3 and DNA methylation were significantly increased in TFAP2C-KD group (P = 0.0045, P = 0.0025). DNMT1 was mainly expressed in nuclei in the TFAP2C-KD group (P = 0.0103). In addition, TFAP2C could bind to the promoter region of SETD2, and the mutation of the TFAP2C binding site resulted in increased activity of SETD2 promoter (P < 0.001). CONCLUSIONS: The knockdown of TFAP2C affects early embryonic development by regulating histone modification and DNA methylation.

TFAP2C exacerbates psoriasis-like inflammation by promoting Th17 and Th1 cells activation through regulating TEAD4 transcription.

BACKGROUND: Psoriasis is one of the chronic and autoimmune skin diseases. It is important to uncover the mechanisms underlying the psoriasis. Transcription factor activator protein (TFAP-2) gamma, also known as AP2-gamma, is a protein encoded by the TFAP2C gene. Immune-mediated pathophysiological processes could be linked to psoriasis, but the mechanism is still unclear. Therefore, to date the cause of psoriasis has not been understood completely. MATERIALS AND METHODS: Psoriasis is a complex disease triggered by genetic, immunological, and environmental stimuli. Keratinocytes play an important role in both initiation and maintenance phases of psoriasis. A psoriatic keratinocyte model was established by stimulating high sensitivity of human epidermal keratinocytes (HaCaT) to topoisomerase inhibitor cell lines using the accumulation of M5 cytokines comprising interleukin (IL)-17A, IL-22, oncostatin M, IL-1α, and tumor necrosis factor-α (TNF-α). The TFAP2C and transcriptional enhanced associate domain 4 (TEAD4) genes expression was evaluated by reverse transcription-quantitative polymerase chain reaction. Western blot analysis was used to examine protein expression. Cell viability (quantitative) of keratinocytes, including cytotoxicity, proliferation, and cell activation, was evaluated by the MTT assay. The relative percentage values of interleukin (IL)-17a, interferon gamma, and IL-4+ cells were measured by flow cytometry. Accordingly, chromatin immunoprecipitation and luciferase reporter assays were applied to evaluate the binding affinity of TFAP2C and TEAD4 promoter. RESULTS: Level of the TFAP2C gene was elevated in the lesional skin of psoriasis patients. On the other hand, silencing of the TFAP2C gene suppressed the proliferation and inflammatory response in M5-induced keratinocytes. In addition, inhibition of TFAP2C alleviated imiquimod (IMQ)-induced skin injury in mice model. We also observed that suppression of TFAP2C inhibited the activation of T-helper 17 (Th17) and Th1 cells in IMQ-induced mice model. Mechanically, TFAP2C promoted TEAD4 transcriptional activation. CONCLUSION: TFAP2C exacerbated psoriasis-like inflammation by increasing the activation of Th17 and Th1 cells by regulating TEAD4 transcription. This finding clearly indicated that TFAP2C could be considered a valuable biomarker for the prevention and treatment for psoriasis.

Generation of Tfap2c-T2A-tdTomato knock-in reporter rats via adeno-associated virus-mediated efficient gene targeting.

Gene editing in mammalian zygotes enables us to generate genetically modified animals rapidly and efficiently. In this study, we compare multiple gene targeting strategies in rat zygotes by generating a novel knock-in reporter rat line to visualize the expression pattern of transcription factor AP-2 gamma (Tfap2c). The targeting vector is designed to replace the stop codon of Tfap2c with T2A-tdTomato sequence. We show that the combination of electroporation-mediated transduction of CRISPR/Cas9 components with adeno-associated virus-mediated transduction of the targeting vector is the most efficient in generating the targeted rat line. The Tfap2c-T2A-tdTomato fluorescence reflects the endogenous expression pattern of Tfap2c in preimplantation embryo, germline, placenta, and forebrain during rat embryo development. The reporter line generated here will be a reliable resource for identifying and purifying Tfap2c expressing cells in rats, and the gene targeting strategy we used can be widely applied for generating desired animals.

Circular RNA circ-ERBB2 promotes HER2-positive breast cancer progression and metastasis via sponging miR-136-5p and miR-198.

BACKGROUND: Circular RNAs (circRNAs) are pivotal regulators of various human cancers and circ-ERBB2 is abnormally expressed in breast cancer cells. However, the role and mechanism of circ-ERBB2 in HER2-positive breast cancer are still unknown. METHODS: The circ-ERBB2 expressions in the tumor tissues of HER2-positive breast cancer patients were tested using quantitative real-time PCR. The circ-ERBB2 function was investigated by cell counting kit 8 assay, Transwell, flow cytometry and Western blot. Mechanistically, fluorescence in situ hybridization, RNA immunoprecipitation, RNA pull-down and dual-luciferase reporter gene assays were conducted to confirm the interaction between circ-ERBB2 and miR-136-5p or miR-198 in HER2-positive breast cancer cells. RESULTS: Circ-ERBB2 was elevated in the tumor tissues of HER2-positive breast cancer patients. Functionally, the interference with circ-ERBB2 repressed HER2-positive breast cancer cell proliferation, migration, invasion and accelerated cell apoptosis. Furthermore, the mechanistic analysis corroborated that circ-ERBB2 acted as a competing endogenous RNA for miR-136-5p or miR-198 to relieve the repressive influence of miR-136-5p or miR-198 on its target transcription factor activator protein 2C (TFAP2C). Meanwhile, in vivo assays further corroborated the oncogenic function of circ-ERBB2 in HER2-positive breast cancer. CONCLUSIONS: Circ-ERBB2 accelerated HER2-positive breast cancer progression through the circ-ERBB2/miR-136-5p/TFAP2C axis or the circ-ERBB2/miR-198/TFAP2C axis.

LncRNA RP11-84E24.3 drives tumorigenesis and epithelial-to-mesenchymal transition of glioma cells by promoting TFAP2C-mediated activation of SNAI1.

PURPOSE: Long noncoding RNAs (LncRNAs) are essential epigenetic regulators with critical roles in tumor initiation and malignant progression; however, the mechanism by which aberrantly expressed lncRNA RP11-84E24.3 regulates the pathogenesis of glioma is not fully understood. Here, we investigate the function of lncRNA RP11-84E24.3 in glioma onset and progression as well as identify a molecular pathway regulated by this lncRNA. METHODS: Differentially expressed lncRNAs related to glioma were identified. The aberrant expression of lncRNA RP11-84E24.3 was verified in samples from patients with glioma as well as glioma cell lines. The role of lncRNA RP11-8424.3 in proliferation, apoptosis, migration, and invasion was assessed using gain- and loss-of function approaches, EdU incorporation, flow cytometry, wound healing and Transwell invasion assays. Western blot analysis was utilized to examine the expression of proteins associated with epithelial-to-mesenchymal transition (EMT). The interaction between lncRNA RP11-84E24.3, TFAP2C and SNAI1 was confirmed using RNA pull-down, ChIP and luciferase reporter assays. RESULTS: LncRNA RP11-84E24.3 was up-regulated in both glioma tissues and cell lines. LncRNA RP11-84E24.3 overexpression enhanced the proliferation, migration and invasion of glioma cells while reducing apoptosis. This was associated with a decrease in E-cadherin expression and an increase in N-cadherin and Vimentin expression. LncRNA RP11-84E24.3 directly targeted TFAP2C protein, resulting in increased SNAI1 expression. Knockdown of TFAP2C or SNAI1 reversed the effects of lncRNA RP11-84E24.3 overexpression, while silencing lncRNA RP11-84E24.3 inhibited tumor formation of glioma cells in vivo. CONCLUSIONS: LncRNA RP11-84E24.3 increased SNAI1 expression by forming a complex with TFAP2C protein, promoting EMT in glioma cells and tumor formation.

In vitro and in silico assessment of the effect of WWOX expression on invasiveness pathways associated with AP-2 transcription factors in bladder cancer.

BACKGROUND: WW Domain Containing Oxidoreductase (WWOX) belongs to the unusual tumor suppressors, whose molecular function is not fully understood in bladder cancer, especially regarding interaction with Activator Protein 2 (AP-2) α/γ transcription factors. Thus, using lentiviral systems we created an in vitro model overexpressing or downregulating WWOX in CAL-29 cell line to assess invasiveness pathways. Surprisingly, while WWOX overexpression was accompanied with increased expression of both AP-2 factors, its downregulation only affected AP-2α level but not AP-2γ which remained high. METHODS: Using cellular models and unpaired t-test or Wilcoxon test, we investigated significant changes in biological processes: clonogenicity, extracellular matrix adhesion, metalloproteinases activity, 3D culture growth, proliferation, mitochondrial redox potential and invasiveness. Relative gene expression acquired through Real-Time qPCR has been analyzed by Welch's t-test. Additionally, using oncoprint analysis we distinguished groups for bioinformatics analyzes in order to perform a follow-up of in vitro experiments. RESULTS: Downregulation of WWOX in bladder cancer cell line intensified ability of single cell to grow into colony, mitochondrial redox potential and proliferation rate. Moreover, these cells shown elevated pro-MMP-2/9 activity but reduced adhesion to collagen I or laminin I, as well as distinct 3D culture growth. Through global in silico profiling we determined that WWOX alters disease-free survival of bladder cancer patients and modulates vital processes through AP-2 downstream effectors. CONCLUSIONS: Our research indicates that WWOX possesses tumor suppressor properties in bladder cancer but consecutive examination is required to entirely understand the contribution of AP-2γ or AP-2α.

METTL3 potentiates resistance to cisplatin through m6 A modification of TFAP2C in seminoma.

Testicular germ cell tumours (TGCTs) rank as the most common malignancy in men aged 20-34 years, and seminomas are the most type of TGCTs. As a crucial anti-tumour agent with explicit toxicity, cisplatin may render resistance through intertwined mechanisms, even in disease entities with high curative ratio, such as seminoma. Previously, we established cisplatin-resistant seminoma TCam-2 (TCam-2/CDDP) cells and showed that epigenetic regulations, such as non-coding RNA (ncRNA) interactions, might orchestrate cell fate decisions in the cisplatin treatment context in seminoma. N6-methyladenosine (m6A) is the most prevalent internal modification in mRNA. In the present study, we assessed cisplatin resistance in seminoma from the perspective of m6 A, another manner of epigenetic modification. The global m6 A enrichment of TCam-2 and TCam-2/CDDP was depicted. Then, we elucidated whether transcription factor-activating enhancer-binding protein 2C (TFAP2C) was functionally m6 A-modified by methyltransferase-like protein 3 (METTL3), which acted as an m6 A 'writer', and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1), which acted as an m6 A 'reader'. Enhanced stability of TFAP2C mRNA promoted seminoma cell survival under cisplatin treatment burden probably through up-regulation of DNA repair-related genes. Hopefully, this study will help improve our understanding of the subtleties of the tumour cellular coping strategy in response to chemotherapy. Targeting factors that are involved in m6 A methylation may be an effective strategy for circumventing cisplatin resistance in seminoma.

MiR-29b-3p cooperates with miR-29c-3p to affect the malignant biological behaviors in T-cell acute lymphoblastic leukemia via TFAP2C/GPX1 axis.

Mounting evidence has illustrated the tumor regulatory roles of microRNAs (miRNAs) in T-cell acute lymphoblastic leukemia (T-ALL), a malignant carcinoma originated from T-cell precursors. However, the possible regulation mechanisms underlying miR-29b/29c-3p in T-ALL have not been interrogated yet. The aim of our study was to probe the association and possible molecular mechanism of miR-29b/29c-3p and Glutathione Peroxidase 1 (GPX1), a predicted highly expressed gene in acute myeloid leukemia (LAML) tissues on the cancer genome atlas (TCGA) website. In our paper, it was observed that GPX1 was relatively overexpressed in T-ALL cells, compared with normal T cells. Loss-of-function assays demonstrated that GPX1 knockdown inhibited the proliferation and activated the apoptosis in T-ALL cells. Then miR-29b/29c-3p was confirmed to regulate GPX1 mRNA and protein expression via decreasing Transcription Factor AP-2 Gamma (TFAP2C) expression. In summary, miR-29b-3p and miR-29c-3p targeted TFAP2C so as to repress GPX1 transcription, thereafter inhibiting GPXA expression. In the end, rescue experiments proved the whole regulation mechanism of miR-29b/29c-3p in T-ALL. Overall, the miR-29b/29c-3p -TFAP2C-GPX1 axis helped us to have a better understanding of T-ALL pathogenesis.

Relevance of iPSC-derived human PGC-like cells at the surface of embryoid bodies to prechemotaxis migrating PGCs.

Pluripotent stem cell-derived human primordial germ cell-like cells (hPGCLCs) provide important opportunities to study primordial germ cells (PGCs). We robustly produced CD38+ hPGCLCs [∼43% of FACS-sorted embryoid body (EB) cells] from primed-state induced pluripotent stem cells (iPSCs) after a 72-hour transient incubation in the four chemical inhibitors (4i)-naïve reprogramming medium and showed transcriptional consistency of our hPGCLCs with hPGCLCs generated in previous studies using various and distinct protocols. Both CD38+ hPGCLCs and CD38- EB cells significantly expressed PRDM1 and TFAP2C, although PRDM1 mRNA in CD38- cells lacked the 3'-UTR harboring miRNA binding sites regulating mRNA stability. Genes up-regulated in hPGCLCs were enriched for cell migration genes, and their promoters were enriched for the binding motifs of TFAP2 (which was identified in promoters of T, NANOS3, and SOX17) and the RREB-1 cell adhesion regulator. In EBs, hPGCLCs were identified exclusively in the outermost surface monolayer as dispersed cells or cell aggregates with strong and specific expression of POU5F1/OCT4 protein. Time-lapse live cell imaging revealed active migration of hPGCLCs on Matrigel. Whereas all hPGCLCs strongly expressed the CXCR4 chemotaxis receptor, its ligand CXCL12/SDF1 was not significantly expressed in the whole EBs. Exposure of hPGCLCs to CXCL12/SDF1 induced cell migration genes and antiapoptosis genes. Thus, our study shows that transcriptionally consistent hPGCLCs can be readily produced from hiPSCs after transition of their pluripotency from the primed state using various methods and that hPGCLCs resemble the early-stage PGCs randomly migrating in the midline region of human embryos before initiation of the CXCL12/SDF1-guided chemotaxis.

Tpbpa-Cre-mediated deletion of TFAP2C leads to deregulation of Cdkn1a, Akt1 and the ERK pathway, causing placental growth arrest.

Loss of TFAP2C in mouse leads to developmental defects in the extra-embryonic compartment with lethality at embryonic day (E)7.5. To investigate the requirement of TFAP2C in later placental development, deletion of TFAP2C was induced throughout extra-embryonic ectoderm at E6.5, leading to severe placental abnormalities caused by reduced trophoblast population and resulting in embryonic retardation by E8.5. Deletion of TFAP2C in TPBPA(+) progenitors at E8.5 results in growth arrest of the junctional zone. TFAP2C regulates its target genes Cdkn1a (previously p21) and Dusp6, which are involved in repression of MAPK signaling. Loss of TFAP2C reduces activation of ERK1/2 in the placenta. Downregulation of Akt1 and reduced activation of phosphorylated AKT in the mutant placenta are accompanied by impaired glycogen synthesis. Loss of TFAP2C led to upregulation of imprinted gene H19 and downregulation of Slc38a4 and Ascl2. The placental insufficiency post E16.5 causes fetal growth restriction, with 19% lighter mutant pups. Knockdown of TFAP2C in human trophoblast choriocarcinoma JAr cells inhibited MAPK and AKT signaling. Thus, we present a model where TFAP2C in trophoblasts controls proliferation by repressing Cdkn1a and activating the MAPK pathway, further supporting differentiation of glycogen cells by activating the AKT pathway.

Expression profile of human porcine endogenous retrovirus A receptors (HuPAR-1, HuPAR-2) and transcription factor activator protein-2γ (TFAP-2C) genes in infected human fibroblasts-Model in vitro.

BACKGROUND: Xenotransplantation of porcine tissues raises concerns, especially in the context of the potential interspecies transmission of porcine endogenous retroviruses (PERVs). To date, the possibility of PERV infections of various human cells has been confirmed in vitro. PERVs infect cells coupling viral Env protein with adequate functional receptor on the surface of the host cell. So far, two PERV-A receptors have been described in humans: HuPAR-1 and HuPAR-2. TFAP-2C was described as one of the transcription factors engaged in the expression of HuPAR-2. METHODS: Bacterial LPS, well known as a strong inflammation inducer, was used in this study to stimulate changes of the expression profile of inflammation-related genes in human cells in vitro. The aim of the study was to investigate the expression profile of HuPAR-1 and HuPAR-2 and TFAP-2C genes in human NHDF cells treated with LPS and/or infected with PERVs from PK15 cells. PERV infection and expression was confirmed by qPCR and RTqPCR. The expression of HuPAR-1, HuPAR-2, and TFAP-2C genes was studied using HGU 133A 2.0 microarrays and RTqPCR. RESULTS: NHDF cells expressed both HuPAR-1 and HuPAR-2 genes with a higher expression of HuPAR-1. LPS down-regulated the expression of HuPAR-1 and TFAP-2C in NHDF cells, but had no effect on HuPAR-2 expression. These changes induced by LPS were more pronounced in the presence of PERV infection. CONCLUSION: As reported previously, treatment of NHDF cells with LPS decreased PERV-A provirus integration and increased PERV-A mRNA expression. PERV infection alone did not modulate the expression of HuPAR-1, HuPAR-2, and TFAP-2C. This is the first study analyzing the expression profile of HuPAR-1, HuPAR-2, and TFAP-2C in NHDF cells treated by LPS and/or infected by PERVs.

TFAP2C increases cell proliferation by downregulating GADD45B and PMAIP1 in non-small cell lung cancer cells.

BACKGROUND: Non-small cell lung cancer (NSCLC) is one of the leading causes of death in the world. NSCLC diagnosed at an early stage can be highly curable with a positive prognosis, but biomarker limitations make it difficult to diagnose lung cancer at an early stage. To identify biomarkers for lung cancer development, we previously focused on the oncogenic roles of transcription factor TFAP2C in lung cancers and revealed the molecular mechanism of several oncogenes in lung tumorigenesis based on TFAP2C-related microarray analysis. RESULTS: In this study, we analyzed microarray data to identify tumor suppressor genes and nine genes downregulated by TFAP2C were screened. Among the nine genes, we focused on growth arrest and DNA-damage-inducible beta (GADD45B) and phorbol-12-myristate-13-acetate-induced protein 1 (PMAIP1) as representative TFAP2C-regulated tumor suppressor genes. It was observed that overexpressed TFAP2C resulted in inhibition of GADD45B and PMAIP1 expressions at both the mRNA and protein levels in NSCLC cells. In addition, downregulation of GADD45B and PMAIP1 by TFAP2C promoted cell proliferation and cell motility, which are closely associated with NSCLC tumorigenesis. CONCLUSION: This study indicates that GADD45B and PMAIP1 could be promising tumor suppressors for NSCLC and might be useful as prognostic markers for use in NSCLC therapy.

Transcription factor AP-2γ induces early Cdx2 expression and represses HIPPO signaling to specify the trophectoderm lineage.

Cell fate decisions are fundamental to the development of multicellular organisms. In mammals the first cell fate decision involves segregation of the pluripotent inner cell mass and the trophectoderm, a process regulated by cell polarity proteins, HIPPO signaling and lineage-specific transcription factors such as CDX2. However, the regulatory mechanisms that operate upstream to specify the trophectoderm lineage have not been established. Here we report that transcription factor AP-2γ (TFAP2C) functions as a novel upstream regulator of Cdx2 expression and position-dependent HIPPO signaling in mice. Loss- and gain-of-function studies and promoter analysis revealed that TFAP2C binding to an intronic enhancer is required for activation of Cdx2 expression during early development. During the 8-cell to morula transition TFAP2C potentiates cell polarity to suppress HIPPO signaling in the outside blastomeres. TFAP2C depletion triggered downregulation of PARD6B, loss of apical cell polarity, disorganization of F-actin, and activation of HIPPO signaling in the outside blastomeres. Rescue experiments using Pard6b mRNA restored cell polarity but only partially corrected position-dependent HIPPO signaling, suggesting that TFAP2C negatively regulates HIPPO signaling via multiple pathways. Several genes involved in regulation of the actin cytoskeleton (including Rock1, Rock2) were downregulated in TFAP2C-depleted embryos. Inhibition of ROCK1 and ROCK2 activity during the 8-cell to morula transition phenocopied TFAP2C knockdown, triggering a loss of position-dependent HIPPO signaling and decrease in Cdx2 expression. Altogether, these results demonstrate that TFAP2C facilitates trophectoderm lineage specification by functioning as a key regulator of Cdx2 transcription, cell polarity and position-dependent HIPPO signaling.

Reduced Gene Dosage of Tfap2c Impairs Trophoblast Lineage Differentiation and Alters Maternal Blood Spaces in the Mouse Placenta.

Tfap2c is required for placental development and trophoblast stem cell maintenance. Deletion of Tfap2c results in early embryonic loss because of failure in placental development. We evaluated the effect of reduced Tfap2c expression on fetal outcome and placental development. Sixty percent of the heterozygous mice were lost directly after birth. Labyrinthine differentiation was impaired, as indicated by enhanced proliferation and inclusions of cobblestone-shaped cell clusters characterized by expression of Tfap2c and glycogen stores. Moreover, expression of marker genes such as Cdx2, Eomes, Gata3, and Ascl2 are decreased in the spongiotrophoblast and indicate a lowered stem cell potential. On Day 18.5 postcoitum, the labyrinth layer of Tfap2c(+/-) placentas exhibited massive hemorrhages in the maternal blood spaces; these hemorrhages might have contributed to the significantly reduced number of live-born pups. These morphological alterations were accompanied by a shift toward sinusoidal trophoblast giant cells as the cell subpopulation lining the maternal sinusoids and toward reduction in expression of the prolactin gene family member Prl2c2, a finding characteristic of the spiral arteries lining trophoblast cells. The trophoblast stem cells heterozygous for Tfap2c exhibited a reduction in the expression level of stem cell markers and in their proliferation and differentiation capacity but did not exhibit changes in marker genes of the trophoblast giant cell lineage. Taken together, these findings indicate that a reduction in the gene dosage of placental Tfap2c leads to morphological changes in the labyrinth at midgestation and in the maternal blood spaces during late pregnancy.

Regulation of Enhancers by SUMOylation Through TFAP2C Binding and Recruitment of HDAC Complex to the Chromatin.

Enhancers are fundamental to gene regulation. Post-translational modifications by the small ubiquitin-like modifiers (SUMO) modify chromatin regulation enzymes, including histone acetylases and deacetylases. However, it remains unclear whether SUMOylation regulates enhancer marks, acetylation at the 27th lysine residue of the histone H3 protein (H3K27Ac). To investigate whether SUMOylation regulates H3K27Ac, we performed genome-wide ChIP-seq analyses and discovered that knockdown (KD) of the SUMO activating enzyme catalytic subunit UBA2 reduced H3K27Ac at most enhancers. Bioinformatic analysis revealed that TFAP2C-binding sites are enriched in enhancers whose H3K27Ac was reduced by UBA2 KD. ChIP-seq analysis in combination with molecular biological methods showed that TFAP2C binding to enhancers increased upon UBA2 KD or inhibition of SUMOylation by a small molecule SUMOylation inhibitor. However, this is not due to the SUMOylation of TFAP2C itself. Proteomics analysis of TFAP2C interactome on the chromatin identified histone deacetylation (HDAC) and RNA splicing machineries that contain many SUMOylation targets. TFAP2C KD reduced HDAC1 binding to chromatin and increased H3K27Ac marks at enhancer regions, suggesting that TFAP2C is important in recruiting HDAC machinery. Taken together, our findings provide insights into the regulation of enhancer marks by SUMOylation and TFAP2C and suggest that SUMOylation of proteins in the HDAC machinery regulates their recruitments to enhancers.