Vigilin interacts with CCCTC-binding factor (CTCF) and is involved in CTCF-dependent regulation of the imprinted genes Igf2 and H19

Chuanxiong Rhizoma extracts prevent liver fibrosis via targeting CTCF-c-MYC-H19 pathway

Objective

Hepatic fibrosis has been widely considered as a conjoint consequence of almost all chronic liver diseases. Chuanxiong Rhizoma (Chuanxiong in Chinese, CX) is a traditional Chinese herbal product to prevent cerebrovascular, gynecologic and hepatic diseases. Our previous study found that CX extracts significantly reduced collagen contraction force of hepatic stellate cells (HSCs). Here, this study aimed to compare the protection of different CX extracts on bile duct ligation (BDL)-induced liver fibrosis and investigate plausible underlying mechanisms.

Methods

The active compounds of CX extracts were identified by high performance liquid chromatography (HPLC). Network pharmacology was used to determine potential targets of CX against hepatic fibrosis. Bile duct hyperplasia and liver fibrosis were evaluated by serologic testing and histopathological evaluation. The expression of targets of interest was determined by quantitative real-time PCR (qPCR) and Western blot.

Results

Different CX extracts were identified by tetramethylpyrazine, ferulic acid and senkyunolide A. Based on the network pharmacological analysis, 42 overlap targets were obtained via merging the candidates targets of CX and liver fibrosis. Different aqueous, alkaloid and phthalide extracts of CX (CXAE, CXAL and CXPHL) significantly inhibited diffuse severe bile duct hyperplasia and thus suppressed hepatic fibrosis by decreasing CCCTC binding factor (CTCF)-c-MYC-long non-coding RNA H19 (H19) pathway in the BDL-induced mouse model. Meanwhile, CX extracts, especially CXAL and CXPHL also suppressed CTCF-c-MYC-H19 pathway and inhibited ductular reaction in cholangiocytes stimulated with taurocholate acid (TCA), lithocholic acid (LCA) and transforming growth factor beta (TGF-β), as illustrated by decreased bile duct proliferation markers.

Conclusion

Our data supported that different CX extracts, especially CXAL and CXPHL significantly alleviated hepatic fibrosis and bile duct hyperplasia via inhibiting CTCF-c-MYC-H19 pathway, providing novel insights into the anti-fibrotic mechanism of CX.

Human IGF2 Gene Epigenetic and Transcriptional Regulation: At the Core of Developmental Growth and Tumorigenic Behavior

Regulation of the human IGF2 gene displays multiple layers of control, which secures a genetically and epigenetically predetermined gene expression pattern throughout embryonal growth and postnatal life. These predominantly nuclear regulatory mechanisms converge on the function of the IGF2-H19 gene cluster on Chromosome 11 and ultimately affect IGF2 gene expression. Deregulation of such control checkpoints leads to the enhancement of IGF2 gene transcription and/or transcript stabilization, ultimately leading to IGF-II peptide overproduction. This type of anomaly is responsible for the effects observed in terms of both abnormal fetal growth and increased cell proliferation, typically observed in pediatric overgrowth syndromes and cancer. We performed a review of relevant experimental work on the mechanisms affecting the human IGF2 gene at the epigenetic, transcriptional and transcript regulatory levels. The result of our work, indeed, provides a wider and diversified scenario for IGF2 gene activation than previously envisioned by shedding new light on its extended regulation. Overall, we focused on the functional integration between the epigenetic and genetic machinery driving its overexpression in overgrowth syndromes and malignancy, independently of the underlying presence of loss of imprinting (LOI). The molecular landscape provided at last strengthens the role of IGF2 in cancer initiation, progression and malignant phenotype maintenance. Finally, this review suggests potential actionable targets for IGF2 gene- and regulatory protein target-degradation therapies.

CTCF and Its Multi-Partner Network for Chromatin Regulation

Architectural proteins are essential epigenetic regulators that play a critical role in organizing chromatin and controlling gene expression. CTCF (CCCTC-binding factor) is a key architectural protein responsible for maintaining the intricate 3D structure of chromatin. Because of its multivalent properties and plasticity to bind various sequences, CTCF is similar to a Swiss knife for genome organization. Despite the importance of this protein, its mechanisms of action are not fully elucidated. It has been hypothesized that its versatility is achieved through interaction with multiple partners, forming a complex network that regulates chromatin folding within the nucleus. In this review, we delve into CTCF's interactions with other molecules involved in epigenetic processes, particularly histone and DNA demethylases, as well as several long non-coding RNAs (lncRNAs) that are able to recruit CTCF. Our review highlights the importance of CTCF partners to shed light on chromatin regulation and pave the way for future exploration of the mechanisms that enable the finely-tuned role of CTCF as a master regulator of chromatin.

Multifaceted functions of RNA-binding protein vigilin in gene silencing, genome stability, and autism-related disorders

RNA-binding proteins (RBPs) are emerging as important players in regulating eukaryotic gene expression and genome stability. Specific RBPs have been shown to mediate various chromatin-associated processes ranging from transcription to gene silencing and DNA repair. One of the prominent classes of RBPs is the KH domain-containing proteins. Vigilin, an evolutionarily conserved KH domain-containing RBP has been shown to be associated with diverse biological processes like RNA transport and metabolism, sterol metabolism, chromosome segregation, and carcinogenesis. We have previously reported that vigilin is essential for heterochromatin-mediated gene silencing in fission yeast. More recently, we have identified that vigilin in humans plays a critical role in efficient repair of DNA double-stranded breaks and functions in homology-directed DNA repair. In this review, we highlight the multifaceted functions of vigilin and discuss the findings in the context of gene expression, genome organization, cancer, and autism-related disorders.

Clinical and Molecular Heterogeneity of Silver-Russell Syndrome and Therapeutic Challenges: A Systematic Review

BACKGROUND

Silver-Russell syndrome (SRS) is a developmental disorder involving extreme growth failure, characteristic facial features and underlying genetic heterogeneity. As the clinical heterogeneity of SRS makes diagnosis a challenging task, the worldwide incidence of SRS could vary from 1:30,000 to 1:100,000. Although various chromosomal, genetic, and epigenetic mutations have been linked with SRS, the cause had only been identified in half of the cases.

MATERIAL AND METHODS

To have a better understanding of the SRS clinical presentation and mutation/ epimutation responsible for SRS, a systematic review of the literature was carried out using appropriate keywords in various scientific databases (PROSPERO protocol registration CRD42021273211). Clinical features of SRS have been compiled and presented corresponding to the specific genetic subtype. An attempt has been made to understand the recurrence risk and the role of model organisms in understanding the molecular mechanisms of SRS pathology, treatment, and management strategies of the affected patients through the analysis of selected literature.

RESULTS

156 articles were selected to understand the clinical and molecular heterogeneity of SRS. Information about detailed clinical features was available for 228 patients only, and it was observed that body asymmetry and relative macrocephaly were most prevalent in cases with methylation defects of the 11p15 region. In about 38% of cases, methylation defects in ICRs or genomic mutations at the 11p15 region have been implicated. Maternal uniparental disomy of chromosome 7 (mUPD7) accounts for about 7% of SRS cases, and rarely, uniparental disomy of other autosomes (11, 14, 16, and 20 chromosomes) has been documented. Mutation in half of the cases is yet to be identified. Studies involving mice as experimental animals have been helpful in understanding the underlying molecular mechanism. As the clinical presentation of the syndrome varies a lot, treatment needs to be individualized with multidisciplinary effort.

CONCLUSION

SRS is a clinically and genetically heterogeneous disorder, with most of the cases being implicated with a mutation in the 11p15 region and maternal disomy of chromosome 7. Recurrence risk varies according to the molecular subtype. Studies with mice as a model organism have been useful in understanding the underlying molecular mechanism leading to the characteristic clinical presentation of the syndrome. Management strategies often need to be individualized due to varied clinical presentations.

Autism-Associated Vigilin Depletion Impairs DNA Damage Repair

Vigilin (Vgl1) is essential for heterochromatin formation, chromosome segregation, and mRNA stability and is associated with autism spectrum disorders and cancer: vigilin, for example, can suppress proto-oncogene c-fms expression in breast cancer. Conserved from yeast to humans, vigilin is an RNA-binding protein with 14 tandemly arranged nonidentical hnRNP K-type homology (KH) domains. Here, we report that vigilin depletion increased cell sensitivity to cisplatin- or ionizing radiation (IR)-induced cell death and genomic instability due to defective DNA repair. Vigilin depletion delayed dephosphorylation of IR-induced γ-H2AX and elevated levels of residual 53BP1 and RIF1 foci, while reducing Rad51 and BRCA1 focus formation, DNA end resection, and double-strand break (DSB) repair. We show that vigilin interacts with the DNA damage response (DDR) proteins RAD51 and BRCA1, and vigilin depletion impairs their recruitment to DSB sites. Transient hydroxyurea (HU)-induced replicative stress in vigilin-depleted cells increased replication fork stalling and blocked restart of DNA synthesis. Furthermore, histone acetylation promoted vigilin recruitment to DSBs preferentially in the transcriptionally active genome. These findings uncover a novel vigilin role in DNA damage repair with implications for autism and cancer-related disorders.

Vigilin interacts with ER-β to protect against palmitic acid-induced granulosa cells apoptosis via inhibiting calcineurin-mediated Drp1 signaling pathway

BACKGROUND

Hypercholesterolemia is one of the causes of female infertility, and as a common fatty acid in follicular fluid, palmitic acid (PA) level plays a vital role in granule cell which is closely related to the developmental potential of follicle.

METHODS

The ovarian granulosa cell-like human granulosa (KGN) cell line and the immortalized normal ovarian surface epithelial cell line (IOSE80) were used to verify the effect of PA on cell viability and apoptosis by MTT and flow cytometry assay, respectively. Then mitochondria damage was confirmed by mitochondrial membrane potential, mitochondrial ROS detection assay and western blot in KGN cells. Thorough luciferase reporter assay and RIP-qPCR, the relationship between vigilin and ER-β was investigated.

RESULTS

In our study, PA induced mitochondrial damage-mediated cell apoptosis of KGN cells was dose-dependently, while PA shown no effects on in IOSE80 cells. Then the role of calcineurin (CnA)-mediated Drp1 signaling pathway on KGN cells was confirmed by treating with Mdivi-1 or FK506T. In addition, the changed level of vigilin and ER-β was observed in cell apoptosis of KGN cells induced by PA. By transfecting vigilin vector or ER-β vector into KGN cells, respectively, vigilin and ER-β were demonstrated to regulate the apoptosis of KGN cells. And vigilin was a binding protein of ER-β mRNA.

CONCLUSION

Vigilin could interact with ER-β mRNA to promote ER-β expression. And Vigilin/ ER-β relieve the mitochondrial damage and cell apoptosis induced by PA through regulating CnA-mediated Drp1 signaling pathway, which revealed the mechanism and strategy of hypercholesterolemia in female infertility.

Knockdown of CTCF reduces the binding of EZH2 and affects the methylation of the SOCS3 promoter in hepatocellular carcinoma

The epigenetic silencing mechanism of suppressor 3 of cytokine signaling (SOCS3) in cancers has not been fully elucidated. Polycomb repressive complexes 2 (PRC2), an important epigenetic regulatory factors, exerts a critical role in repressing the initial phase of gene transcription. Whether PRC2 participates the down- regulation of SOCS3 in Hepatocellular carcinoma (HCC) remains unclear and how does PRC2 be recruited target gene still needs to explore. In this study, Using TCGA HCC dataset, and detecting HCC tissue specimens and cell lines, we found that SOCS3 expression in HCC was inversely related to that of EZH2, and depended on its promoter methylation status. CTCF, vigilin, EZH2 and H3K27me3 were enriched at CTCF and EZH2 binding sites on the methylated SOCS3 gene promoter. The depletion of CTCF did not affect expression of EZH2 and DNMT1, but decrease recruitment of CTCF, vigilin, EZH2 and H3K27me3. Further, knockdown of CTCF led to a loss of methylation of the methylated SOCS3 promoter, which sequentially increased the expression of SOCS3 and decreased the expression of pSTAT3, the downstream effector. These findings suggest that the CTCF dependent recruitment of EZH2 to the SOCS3 gene promoter is likely to participate in the epigenetic silencing of SOCS3 and in regulating its gene expression.

The role of long non-coding RNA H19 in breast cancer

Breast cancer is the most common malignant tumor in women in the majority of countries, such as China, Britain and Australia, and its morbidity and mortality rates remain very high. Long non-coding RNAs (lncRNAs) are non-coding RNAs (ncRNAs) >200 nucleotides in length that lack open reading frames. LncRNA H19 is a transcription product of the H19 gene, and the aberrant expression of H19 can be demonstrated in various types of tumor cell. The purpose of the present review was to elaborate the role of H19 in breast cancer. H19 can regulate gene expression in breast cancer at multiple levels, including epigenetic, transcriptional and posttranscriptional. The abnormal expression of H19 is closely associated with the tumorigenesis and progression of breast cancer via different underlying molecular mechanisms, such as encoding microRNA-675, competing endogenous RNA regulation and interacting with MYC. A large number of clinical studies have suggested that H19 can serve as a potential biomarker for the diagnosis of breast cancer. High expression levels of H19 increases the drug resistance of breast cancer cells and is associated with poor prognosis within patients with breast cancer. Therefore, serum H19 levels may have momentous significance in the clinical setting.

One protein to rule them all: The role of CCCTC-binding factor in shaping human genome in health and disease

The eukaryotic genome, constituting several billion base pairs, must be contracted to fit within the volume of a nucleus where the diameter is on the scale of μm. The 3D structure and packing of such a long sequence cannot be left to pure chance, as DNA must be efficiently used for its primary roles as a matrix for transcription and replication. In recent years, methods like chromatin conformation capture (including 3C, 4C, Hi-C, ChIA-PET and Multi-ChIA) and optical microscopy have advanced substantially and have shed new light on how eukaryotic genomes are hierarchically organized; first into 10-nm fiber, next into DNA loops, topologically associated domains and finally into interphase or mitotic chromosomes. This knowledge has allowed us to revise our understanding regarding the mechanisms governing the process of DNA organization. Mounting experimental evidence suggests that the key element in the formation of loops is the binding of the CCCTC-binding factor (CTCF) to DNA; a protein that can be referred to as the chief organizer of the genome. However, CTCF does not work alone but in cooperation with other proteins, such as cohesin or Yin Yang 1 (YY1). In this short review, we briefly describe our current understanding of the structure of eukaryotic genomes, how they are established and how the formation of DNA loops can influence gene expression. We discuss the recent discoveries describing the 3D structure of the CTCF-DNA complex and the role of CTCF in establishing genome structure. Finally, we briefly explain how various genetic disorders might arise as a consequence of mutations in the CTCF target sequence or alteration of genomic imprinting.

Insulin-like growth factor 2 expression in prostate cancer is regulated by promoter-specific methylation

Deregulation of the insulin-like growth factor (IGF) axis and dysbalance of components of the IGF system as potential therapeutic targets have been described in different tumor types. IGF2 is a major embryonic growth factor and an important activator of IGF signaling. It is regulated by imprinting in a development- and tissue-dependent manner and has been implicated in a broad range of malignancies including prostate cancer (PCa). Loss of imprinting (LOI) usually results in bi-allelic gene expression and increased levels of IGF2. However, the regulatory mechanisms and the pathophysiological impact of altered IGF2 expression in PCa remain elusive. Here, we show that in contrast to many other tumors, IGF2 mRNA and protein levels were decreased in 80% of PCa in comparison with non-neoplastic adjacent prostate and were independent of LOI status. Instead, IGF2 expression in both tumors and adjacent prostate depended on preferential usage of the IGF2 promoters P3 and P4. Decreased IGF2 expression in tumors was strongly related to hypermethylation of these two promoters. Methylation of the A region in promoter P4 correlated specifically with IGF2 expression in the 20% of PCa where IGF2 was higher in tumors than in adjacent prostate. We conclude that IGF2 is downregulated in most PCa and may be particularly relevant during early stages of tumor development or during chemotherapy and androgen deprivation. PCa differs from other tumors in that IGF2 expression is mainly regulated through methylation of promoter-specific and not by imprinting. Targeting of promoter-specific regions may have relevance for the adjuvant treatment of PCa.

Vigilin interacts with CTCF and is involved in the maintenance of imprinting of IGF2 through a novel RNA-mediated mechanism

Accumulating evidence has revealed the imprinting of insulin-like growth factor-2 gene (IGF2) is maintained by binding of CCCTC binding factor (CTCF) to the unmethylated imprinting control region (ICR) between IGF2 and H19 genes. We have previously reported that high-density lipoprotein binding protein (HDLBP/vigilin), a multiKH-domain protein, interacts with CTCF and coexists with it at several CTCF-binding sites on the ICR to regulate general gene expression of IGF2. However, the impact of the interaction on imprinting of IGF2 remains unclear. Here, we demonstrate that cooperation of vigilin and CTCF protects IGF2 from losing of imprinting. Pull-down experiments show that KH1-7 domains of vigilin interact with zinc-finger domains of CTCF. We also display that some RNAs participate in the vigilin-CTCF interaction, one of which is H19 long noncoding RNA (lncRNA). Furthermore, we confirm that H19 lncRNA-knockdown alters the imprinting of IGF2. These data suggest that vigilin interacts with CTCF, mediated by H19 lncRNA, to keep the imprinting of IGF2.

A jack of all trades: the RNA-binding protein vigilin

The vigilin family of proteins is evolutionarily conserved from yeast to humans and characterized by the proteins' 14 or 15 hnRNP K homology (KH) domains, typically associated with RNA-binding. Vigilin is the largest RNA-binding protein (RBP) in the KH domain-containing family and one of the largest RBP known to date. Since its identification 30 years ago, vigilin has been shown to bind over 700 mRNAs and has been associated with cancer progression and cardiovascular disease. We provide a brief historic overview of vigilin research and outline the proteins' different functions, focusing on maintenance of genome ploidy, heterochromatin formation, RNA export, as well as regulation of translation, mRNA transport, and mRNA stability. The multitude of associated functions is reflected by the large number of identified interaction partners, ranging from tRNAs, mRNAs, ribosomes and ribosome-associated proteins, to histone methyltransferases and DNA-dependent protein kinases. Most of these partners bind to vigilin's carboxyterminus, and the two most C-terminal KH domains of the protein, KH13 and KH14, represent the main mRNA-binding interface. Since the nuclear functions of vigilins in particular are not conserved, we outline a model for the basal functions of vigilins, as well as those which were acquired during the transition from unicellular organisms to metazoa. WIREs RNA 2017, 8:e1448. doi: 10.1002/wrna.1448 For further resources related to this article, please visit the WIREs website.

Spatial Cross-Talk between Oxidative Stress and DNA Replication in Human Fibroblasts

MS-based proteomics has been applied to a differential network analysis of the nuclear-cytoplasmic subcellular distribution of proteins between cell-cycle arrest: (a) at the origin activation checkpoint for DNA replication, or (b) in response to oxidative stress. Significant changes were identified for 401 proteins. Cellular response combines changes in trafficking and in total abundance to vary the local compartmental abundances that are the basis of cellular response. Appreciable changes for both perturbations were observed for 245 proteins, but cross-talk between oxidative stress and DNA replication is dominated by 49 proteins that show strong changes for both. Many nuclear processes are influenced by a spatial switch involving the proteins {KPNA2, KPNB1, PCNA, PTMA, SET} and heme/iron proteins HMOX1 and FTH1. Dynamic spatial distribution data are presented for proteins involved in caveolae, extracellular matrix remodelling, TGFβ signaling, IGF pathways, emerin complexes, mitochondrial protein import complexes, spliceosomes, proteasomes, and so on. The data indicate that for spatially heterogeneous cells cross-compartmental communication is integral to their system biology, that coordinated spatial redistribution for crucial protein networks underlies many functional changes, and that information on dynamic spatial redistribution of proteins is essential to obtain comprehensive pictures of cellular function. We describe how spatial data of the type presented here can provide priorities for further investigation of crucial features of high-level spatial coordination across cells. We suggest that the present data are related to increasing indications that much of subcellular protein transport is constitutive and that perturbation of these constitutive transport processes may be related to cancer and other diseases. A quantitative, spatially resolved nucleus-cytoplasm interaction network is provided for further investigations.

Paxillin-dependent regulation of IGF2 and H19 gene cluster expression

Paxillin (PXN) is a focal adhesion protein that has been implicated in signal transduction from the extracellular matrix. Recently, it has been shown to shuttle between the cytoplasm and the nucleus. When inside the nucleus, paxillin promotes cell proliferation. Here, we introduce paxillin as a transcriptional regulator of IGF2 and H19 genes. It does not affect the allelic expression of the two genes; rather, it regulates long-range chromosomal interactions between the IGF2 or H19 promoter and a shared distal enhancer on an active allele. Specifically, paxillin stimulates the interaction between the enhancer and the IGF2 promoter, thus activating IGF2 gene transcription, whereas it restrains the interaction between the enhancer and the H19 promoter, downregulating the H19 gene. We found that paxillin interacts with cohesin and the mediator complex, which have been shown to mediate long-range chromosomal looping. We propose that these interactions occur at the IGF2 and H19 gene cluster and are involved in the formation of loops between the IGF2 and H19 promoters and the enhancer, and thus the expression of the corresponding genes. These observations contribute to a mechanistic explanation of the role of paxillin in proliferation and fetal development.

CTCF as a multifunctional protein in genome regulation and gene expression

CCCTC-binding factor (CTCF) is a highly conserved zinc finger protein and is best known as a transcription factor. It can function as a transcriptional activator, a repressor or an insulator protein, blocking the communication between enhancers and promoters. CTCF can also recruit other transcription factors while bound to chromatin domain boundaries. The three-dimensional organization of the eukaryotic genome dictates its function, and CTCF serves as one of the core architectural proteins that help establish this organization. The mapping of CTCF-binding sites in diverse species has revealed that the genome is covered with CTCF-binding sites. Here we briefly describe the diverse roles of CTCF that contribute to genome organization and gene expression.

Disruption of human vigilin impairs chromosome condensation and segregation

Appropriate packaging and condensation are critical for eukaryotic chromatin's accommodation and separation during cell division. Human vigilin, a multi-KH-domain nucleic acid-binding protein, is associated with alpha satellites of centromeres. DDP1, a vigilin's homolog, is implicated with chromatin condensation and segregation. The expression of vigilin was previously reported to elevate in highly proliferating tissues and increased in a subset of hepatocellular carcinoma patients. Other studies showed that vigilin interacts with CTCF, contributes to regulation of imprinted genes Igf2/H19, and colocalizes with HP1α on heterochromatic satellite 2 and β-satellite repeats. These studies indicate that human vigilin might be involved in chromatin remodeling and regular cell growth. To investigate the potential role of human vigilin in cell cycle, the correlations between vigilin and chromosomal condensation and segregation were studied. Depletion of human vigilin by RNA interference in HepG2 cells resulted in chromosome undercondensation and various chromosomal defects during mitotic phase, including chromosome misalignments, lagging chromosomes, and chromosome bridges. Aberrant polyploid nucleus in telophase was also observed. Unlike the abnormal staining pattern of chromosomes, the shape of spindle was normal. Furthermore, the chromatin showed a greater sensitivity to MNase digestion. Collectively, our findings show that human vigilin apparently participates in chromatin condensation and segregation.

Hidden among the crowd: differential DNA methylation-expression correlations in cancer occur at important oncogenic pathways

DNA methylation is a frequent epigenetic mechanism that participates in transcriptional repression. Variations in DNA methylation with respect to gene expression are constant, and, for unknown reasons, some genes with highly methylated promoters are sometimes overexpressed. In this study we have analyzed the expression and methylation patterns of thousands of genes in five groups of cancer and normal tissue samples in order to determine local and genome-wide differences. We observed significant changes in global methylation-expression correlation in all the neoplasms, which suggests that differential correlation events are frequent in cancer. A focused analysis in the breast cancer cohort identified 1662 genes whose correlation varies significantly between normal and cancerous breast, but whose DNA methylation and gene expression patterns do not change substantially. These genes were enriched in cancer-related pathways and repressive chromatin features across various model cell lines, such as PRC2 binding and H3K27me3 marks. Substantial changes in methylation-expression correlation indicate that these genes are subject to epigenetic remodeling, where the differential activity of other factors break the expected relationship between both variables. Our findings suggest a complex regulatory landscape where a redistribution of local and large-scale chromatin repressive domains at differentially correlated genes (DCGs) creates epigenetic hotspots that modulate cancer-specific gene expression.

The role of CCCTC-binding factor (CTCF) in genomic imprinting, development, and reproduction

CCCTC-binding factor (CTCF) is the major protein involved in insulator activity in vertebrates, with widespread DNA binding sites in the genome. CTCF participates in many processes related to global chromatin organization and remodeling, contributing to the repression or activation of gene transcription. It is also involved in epigenetic reprogramming and is essential during gametogenesis and embryo development. Abnormal DNA methylation patterns at CTCF motifs may impair CTCF binding to DNA, and are related to fertility disorders in mammals. Therefore, CTCF and its binding sites are important candidate regions to be investigated as molecular markers for gamete and embryo quality. This article reviews the role of CTCF in genomic imprinting, gametogenesis, and early embryo development and, moreover, highlights potential opportunities for environmental influences associated with assisted reproductive techniques (ARTs) to affect CTCF-mediated processes. We discuss the potential use of CTCF as a molecular marker for assessing gamete and embryo quality in the context of improving the efficiency and safety of ARTs.