WNT responsive SUMOylation of ZIC5 promotes murine neural crest cell development via multiple effects on transcription

Zic family member 5 promotes RIO kinase 3 expression to enhance pancreatic cancer survival

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies with few effective therapies available. We previously determined the essential role of Zic family member 5 (ZIC5) in the survival of PDAC cells. In this study, we showed that targeting ZIC5 can effectively shrink PDAC tumors treated with gemcitabine in vivo and investigated the molecular mechanisms involved. When tumor-bearing mice were injected intravenously with ZIC5-targeting small interfering RNA, tumor volume was significantly reduced by gemcitabine treatment. RNA-sequencing analysis was used to identify the genes affected by ZIC5 knockdown. Among these, we selected the genes whose mRNA expression levels correlated with that of ZIC5 in pancreatic cancer and those associated with poor prognosis in patients with pancreatic cancer. Further analysis revealed that RIO kinase 3 (RIOK3) promotes PDAC cell survival, whereas ALDH3B1, PTGES, and TUFT1 contribute to gemcitabine resistance in MiaPaca-2 cells. We identified RIOK3 as a direct target gene of ZIC5 using ChIP and luciferase assays. Furthermore, stable expression of RIOK3 in PANC-1 cells reversed the reduction in cell number following ZIC5 knockdown. These findings highlight RIOK3 as a critical target of ZIC5, which is involved in survival signaling in PDAC cells.

Zic3 enables bimodal regulation of tyrosine hydroxylase expression in olfactory bulb and midbrain-derived neurons

Tyrosine hydroxylase (TH) is the rate-limiting enzyme involved in the biosynthesis of catecholamines such as dopamine, norepinephrine, and epinephrine expressed in various regions of the brain, including the olfactory bulb (OB) and midbrain (MB). Previous studies demonstrated Zinc Finger transcription factor of the Cerebellum 3 (ZIC3) to regulate forebrain development, and Zic1/Zic3 compound mutant mice displayed reduced OB size. However, the precise role of ZIC3 in TH regulation remains elusive. In this study, we attempted to understand the role of ZIC3 in TH regulation and its underlying mechanism. While loss of function of Zic3 in OB-derived neurons led to down-regulation of TH expression, it could be rescued by over-expression of shRNA-resistant Zic3. Immunohistochemistry of OB of Zic3 null mice showed a similar reduction in expression of TH. Promoter of TH lacks the consensus ZIC3 binding region, and mechanistic insights revealed ZIC3 to regulate TH expression by interacting with ER81, a known TH regulator. ZIC3 interaction with ER81 is indispensable for ER81 binding to the Th promoter, and it fine-tunes ER81-mediated Th regulation in OB. In MB, where TH levels are highest after birth, ZIC3 regulates TH expression both in vitro and in vivo. TH was significantly reduced in P0 Zic3 null mice, as well as in Zic3 shRNA stereotactically delivered in 7-month-old mice. Mechanistically, in the absence of ER81 in MB, ZIC3 chooses an alternative approach of binding to Pitx3 promoter-a Dopaminergic (DA) fate determinant. Under the ectopic expression of ER81 in MB derived neurons, the propensity of ZIC3 binding to Pitx3 promoter is compromised, and its occupancy on Th promoter encompassing ER81 binding site is established, finally culminating in desired TH expression. Together, these findings reveal a unique ZIC3-mediated bimodal regulation of TH in OB and MB derived neurons.

Transient pharmacological inhibition of SUMOylation during pregnancy induces craniofacial malformations in offspring mice

Cell identity plays a pivotal role in embryo development, guiding the process of cellular differentiation essential for tissue and organ formation. Post-translational modification by the ubiquitin-related SUMO protein acts as a chromatin barrier to cell fate conversions. While SUMOylation deficiency is incompatible with mammalian embryonic development, haploinsufficiency for the SUMOylation machinery's E1 enzyme, UBA2, leads to various phenotypic traits in humans, including craniofacial malformations and aplasia cutis congenita. To investigate SUMO's role in organogenesis, SUMOylation was transiently suppressed using a specific pharmacological inhibitor, TAK981, administered during the early post-implantation embryo stage. A high-concentration injection led to embryonic lethality associated with epigenetic scars and alterations in nuclear and nucleolar integrity observed in treated embryo-derived fibroblasts. Lower-concentration injections resulted in viable mice with craniofacial deformities often accompanied by hydrocephalus, syndactyly and an aplasia cutis-like phenotype. Transcriptomic analysis revealed the repression of genes involved in neural crest differentiation in the TAK981-treated embryos as well as the overexpression of the Fgfr gene family in the adult TAK981 progeny. These genes, expressed in neural crest derivatives, are known for their gain-of-function mutations linked to human craniosynostosis syndromes, suggesting that potential overactivation of the FGF signaling pathway may contribute to the malformations observed in TAK981 progeny. Altogether, disruption of the SUMOylation/deSUMOylation equilibrium during a short embryonic period is sufficient to induce persistent cellular defects and transcriptional alterations, resulting in severe offspring malformations. In conclusion, the SUMO inhibitor TAK981 has teratogenic effects, disrupting normal fetal development and causing congenital disabilities reminiscent of traits observed in UBA2-related syndrome.

Research progress of ZIC5 for tumor metastasis

The zinc finger protein of the cerebellum (ZIC) family comprises five members (ZIC1-5), homologous with the odd-paired (OPA) gene in Drosophila melanogila. These transcription factors contain five Cys2His zinc finger domains, constituting one of the most abundant transcription factor families in human cells. ZIC proteins significantly contribute to transcriptional regulation and chromatin remodeling. As a member of the ZIC family, ZIC5 is essential for animal growth and development. Numerous studies have investigated the connection between ZIC proteins and cancer as well as tumor metastases in recent years. Many studies have found that within tumor tissues, the transcription and translation processes increase the expression of ZIC5 which is linked to tumor aggressiveness. This review aims to provide an objective summary of the impact of ZIC5 on tumor metastasis and consider the potential application of ZIC5 targets in both tumor therapy and the early detection of cancer.

Identification and Analysis of ZIC-Related Genes in Cerebellum of Autism Spectrum Disorders

Objective

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with significant genetic heterogeneity. The ZIC gene family can regulate neurodevelopment, especially in the cerebellum, and has been implicated in ASD-like behaviors in mice. We performed bioinformatic analysis to identify the ZIC gene family in the ASD cerebellum.

Methods

We explored the roles of ZIC family genes in ASD by investigating (i) the association of ZIC genes with ASD risk genes from the Simons Foundation Autism Research Initiative (SFARI) database and ZIC genes in the brain regions of the Human Protein Atlas (HPA) database; (ii) co-expressed gene networks of genes positively and negatively correlated with ZIC1, ZIC2, and ZIC3, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and receiver operating characteristic (ROC) curve analysis of genes in these networks; and (iii) the relationship between ZIC1, ZIC2, ZIC3, and their related genes with cerebellar immune cells and stromal cells in ASD patients.

Results

(i) ZIC1, ZIC2, and ZIC3 were associated with neurodevelopmental disorders and risk genes related to ASD in the human cerebellum and (ii) ZIC1, ZIC2, and ZIC3 were highly expressed in the cerebellum, which may play a pathogenic role by affecting neuronal development and the cerebellar internal environment in patients with ASD, including immune cells, astrocytes, and endothelial cells. (iii) OLFM3, SLC27A4, GRB2, TMED1, NR2F1, and STRBP are closely related to ZIC1, ZIC2, and ZIC3 in ASD cerebellum and have good diagnostic accuracy. (iv) ASD mice in the maternal immune activation model demonstrated that Zic3 and Nr2f1 levels were decreased in the immune-activated cerebellum.

Conclusion

Our study supports the role of ZIC1, ZIC2, and ZIC3 in ASD pathogenesis and provides potential targets for early and accurate prediction of ASD.

SUMOylation effects on neural stem cells self-renewal, differentiation, and survival

SUMO (small ubiquitin-like modifier) conjugation or SUMOylation, a post-translational modification, is a crucial regulator of protein function and cellular processes. In the context of neural stem cells (NSCs), SUMOylation has emerged as a key player, affecting their proliferation, differentiation, and survival. By modifying transcription factors, such as SOX1, SOX2, SOX3, SOX6, Bmi1, and Nanog, SUMOylation can either enhance or impair their transcriptional activity, thus impacting on NSCs self-renewal. Moreover, SUMOylation regulates neurogenesis and neuronal differentiation by modulating key proteins, such as Foxp1, Mecp2, MEF2A, and SOX10. SUMOylation is also crucial for the survival and proliferation of NSCs in both developing and adult brains. By regulating the activity of transcription factors, coactivators, and corepressors, SUMOylation acts as a molecular switch, inducing cofactor recruitment and function during development. Importantly, dysregulation of NSCs SUMOylation has been implicated in various disorders, including embryonic defects, ischemic cerebrovascular disease, glioma, and the harmful effects of benzophenone-3 exposure. Here we review the main findings on SUMOylation-mediated regulation of NSCs self-renewal, differentiation and survival. Better understanding NSCs SUMOylation mechanisms and its functional consequences might provide new strategies to promote neuronal differentiation that could contribute for the development of novel therapies targeting neurodegenerative diseases.

ZIC5 promotes aggressiveness and cancer stemness in cervical squamous cell carcinoma

BACKGROUND

Cervical cancer is one of the major malignancies causing morbidity and mortality in women in developing countries. ZIC5 has been found to be associated with a variety of cancers, yet the expression and molecular function of ZIC5 in cervical squamous cell carcinoma (CESC) is unknown.

METHODS

We examined the expression of ZIC5 in tumors and normal tissues of CESC patients using immunohistochemistry, immunoblotting and fluorescent quantitative PCR, and used statistical methods to explore its relationship with clinical manifestations. Next, we constructed ZIC5 knockdown and overexpression CESC cell lines to observe the effect of ZIC5 on the proliferation and metastasis of CESC cells. Finally, we applied a nude mouse xenograft tumor model to observe the effect of ZIC5 on tumorigenesis in vivo.

RESULTS

Our results showed that the expression of ZIC5 was higher in cancer tissues than in normal tissues. Prognostic analysis showed that ZIC5 expression level was an independent prognostic factor in CESC patients, and the results of Transwell, CCK-8 and wound healing assays confirmed that overexpression of ZIC5 could promote the proliferation and migration of CESC cells. A nude mouse xenograft tumor model showed that knockdown of ZIC5 inhibited tumor growth in vivo. Database, immunoblotting assay and in vitro sphere-forming assay confirmed that ZIC5 could promote the stemness of CESC cells.

CONCLUSION

ZIC5 is a factor that indicates a poor prognosis of CESC patients and promotes stemness in CESC cells. ZIC5 may be a potential biomarker and therapeutic target for CESC patients.

Time to go: neural crest cell epithelial-to-mesenchymal transition

Neural crest cells (NCCs) are a dynamic, multipotent, vertebrate-specific population of embryonic stem cells. These ectodermally-derived cells contribute to diverse tissue types in developing embryos including craniofacial bone and cartilage, the peripheral and enteric nervous systems and pigment cells, among a host of other cell types. Due to their contribution to a significant number of adult tissue types, the mechanisms that drive their formation, migration and differentiation are highly studied. NCCs have a unique ability to transition from tightly adherent epithelial cells to mesenchymal and migratory cells by altering their polarity, expression of cell-cell adhesion molecules and gaining invasive abilities. In this Review, we discuss classical and emerging factors driving NCC epithelial-to-mesenchymal transition and migration, highlighting the role of signaling and transcription factors, as well as novel modifying factors including chromatin remodelers, small RNAs and post-translational regulators, which control the availability and longevity of major NCC players.

Regulation of SUMOylation Targets Associated With Wnt/β-Catenin Pathway

Wnt/β-catenin signaling is a delicate and complex signal transduction pathway mediated by multiple signaling molecules, which plays a significant role in regulating human physiology and pathology. Abnormally activated Wnt/β-catenin signaling pathway plays a crucial role in promoting malignant tumor occurrence, development, recurrence, and metastasis, particularly in cancer stem cells. Studies have shown that the Wnt/β-catenin signaling pathway controls cell fate and function through the transcriptional and post-translational regulation of omics networks. Therefore, precise regulation of Wnt/β-catenin signaling as a cancer-targeting strategy may contribute to the treatment of some malignancies. SUMOylation is a post-translational modification of proteins that has been found to play a major role in the Wnt/β-catenin signaling pathway. Here, we review the complex regulation of Wnt/β-catenin signaling by SUMOylation and discuss the potential targets of SUMOylation therapy.

Zic family member 5 promotes survival in human pancreatic cancer and cholangiocarcinoma cells

Pancreatic ductal adenocarcinoma (PDAC) and cholangiocarcinoma (CCA) are malignant tumors with poor prognosis because of the limited effectiveness of traditional chemotherapy and few effective molecular therapeutic agents. Here, we determined the essential roles of Zic family member 5 (ZIC5) in the survival of PDAC and CCA cells. The results showed that ZIC5 is strongly expressed in PDAC and CCA tissues, while ZIC5 expression is barely observed in most normal human adult tissues. Furthermore, ZIC5 expression is related to poor prognosis of patients with PDAC. ZIC5 knockdown via small interfering RNA decreased the phosphorylation of signal transducer and activator of transcription 3 (STAT3), a protein that is associated with PDAC and CCA aggressiveness. However, ZIC5 knockdown induced cell death regardless of STAT3 activation, which is promoted by interleukin (IL) −6, a factor associated with inflammation. Furthermore, knockdown of ZIC5 in PDAC and CCA cells additively or synergistically induced apoptosis with the anti-cancer drug gemcitabine. Thus, ZIC5 constitutes a potential therapeutic target for the treatment of PDAC and CCA.

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ZIC5 is expressed in PDAC and CCA, while barely observed in normal adult tissues.

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ZIC5 expression is related to poor prognosis of patients with PDAC.

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ZIC5 knockdown induces apoptosis in several PDAC and CCA cell lines.

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Knockdown of ZIC5 additively or synergistically induces apoptosis with gemcitabine.

SUMOylation Potentiates ZIC Protein Activity to Influence Murine Neural Crest Cell Specification

The mechanisms of neural crest cell induction and specification are highly conserved among vertebrate model organisms, but how similar these mechanisms are in mammalian neural crest cell formation remains open to question. The zinc finger of the cerebellum 1 (ZIC1) transcription factor is considered a core component of the vertebrate gene regulatory network that specifies neural crest fate at the neural plate border. In mouse embryos, however, Zic1 mutation does not cause neural crest defects. Instead, we and others have shown that murine Zic2 and Zic5 mutate to give a neural crest phenotype. Here, we extend this knowledge by demonstrating that murine Zic3 is also required for, and co-operates with, Zic2 and Zic5 during mammalian neural crest specification. At the murine neural plate border (a region of high canonical WNT activity) ZIC2, ZIC3, and ZIC5 function as transcription factors to jointly activate the Foxd3 specifier gene. This function is promoted by SUMOylation of the ZIC proteins at a conserved lysine immediately N-terminal of the ZIC zinc finger domain. In contrast, in the lateral regions of the neurectoderm (a region of low canonical WNT activity) basal ZIC proteins act as co-repressors of WNT/TCF-mediated transcription. Our work provides a mechanism by which mammalian neural crest specification is restricted to the neural plate border. Furthermore, given that WNT signaling and SUMOylation are also features of non-mammalian neural crest specification, it suggests that mammalian neural crest induction shares broad conservation, but altered molecular detail, with chicken, zebrafish, and Xenopus neural crest induction.