Lineage-specific roles of the cytoplasmic polyadenylation factor CPEB4 in the regulation of melanoma drivers

Accurate isoform quantification by joint short- and long-read RNA-sequencing

Accurate quantification of transcript isoforms is crucial for understanding gene regulation, functional diversity, and cellular behavior. Existing RNA sequencing methods have significant limitations: short-read (SR) sequencing provides high depth but struggles with isoform deconvolution, whereas long-read (LR) sequencing offers isoform resolution at the cost of lower depth, higher noise, and technical biases. Addressing this gap, we introduce Multi-Platform Aggregation and Quantification of Transcripts (MPAQT), a generative model that combines the complementary strengths of different sequencing platforms to achieve state-of-the-art isoform-resolved transcript quantification, as demonstrated by extensive simulations and experimental benchmarks. By applying MPAQT to an in vitro model of human embryonic stem cell differentiation into cortical neurons, followed by machine learning-based modeling of transcript abundances, we show that untranslated regions (UTRs) are major determinants of isoform proportion and exon usage; this effect is mediated through isoform-specific sequence features embedded in UTRs, which likely interact with RNA-binding proteins that modulate mRNA stability. These findings highlight MPAQT's potential to enhance our understanding of transcriptomic complexity and underline the role of splicing-independent post-transcriptional mechanisms in shaping the isoform and exon usage landscape of the cell.

CSDE1 Intracellular Distribution as a Biomarker of Melanoma Prognosis

RNA-binding proteins are emerging as critical modulators of oncogenic cell transformation, malignancy and therapy resistance. We have previously found that the RNA-binding protein Cold Shock Domain containing protein E1 (CSDE1) promotes invasion and metastasis of melanoma, the deadliest form of skin cancer and also a highly heterogeneous disease in need of predictive biomarkers and druggable targets. Here, we design a monoclonal antibody useful for IHC in the clinical setting and use it to evaluate the prognosis potential of CSDE1 in an exploratory cohort of 149 whole tissue sections including benign nevi and primary tumors and metastasis from melanoma patients. Contrary to expectations for an oncoprotein, we observed a global decrease in CSDE1 levels with increasing malignancy. However, the CSDE1 cytoplasmic/nuclear ratio exhibited a positive correlation with adverse clinical features of primary tumors and emerged as a robust indicator of progression free survival in cutaneous melanoma, highlighting the potential of CSDE1 as a biomarker of prognosis. Our findings provide a novel feature for prognosis assessment and highlight the intricacies of RNA-binding protein dynamics in cancer progression.

Asymmetric and parallel subgenome selection co-shape common carp domestication

BACKGROUND

The common carp (Cyprinus carpio) might best represent the domesticated allopolyploid animals. Although subgenome divergence which is well-known to be a key to allopolyploid domestication has been comprehensively characterized in common carps, the link between genetic architecture underlying agronomic traits and subgenome divergence is unknown in the selective breeding of common carps globally.

RESULTS

We utilized a comprehensive SNP dataset in 13 representative common carp strains worldwide to detect genome-wide genetic variations associated with scale reduction, vibrant skin color, and high growth rate in common carp domestication. We identified numerous novel candidate genes underlie the three agronomically most desirable traits in domesticated common carps, providing potential molecular targets for future genetic improvement in the selective breeding of common carps. We found that independently selective breeding of the same agronomic trait (e.g., fast growing) in common carp domestication could result from completely different genetic variations, indicating the potential advantage of allopolyploid in domestication. We observed that candidate genes associated with scale reduction, vibrant skin color, and/or high growth rate are repeatedly enriched in the immune system, suggesting that domestication of common carps was often accompanied by the disease resistance improvement.

CONCLUSIONS

In common carp domestication, asymmetric subgenome selection is prevalent, while parallel subgenome selection occurs in selective breeding of common carps. This observation is not due to asymmetric gene retention/loss between subgenomes but might be better explained by reduced pleiotropy through transposable element-mediated expression divergence between ohnologs. Our results demonstrate that domestication benefits from polyploidy not only in plants but also in animals.

The CCR4-NOT complex suppresses untimely translational activation of maternal mRNAs

Control of mRNA poly(A) tails is essential for regulation of mRNA metabolism, specifically translation efficiency and mRNA stability. Gene expression in maturing oocytes relies largely on post-transcriptional regulation, as genes are transcriptionally silent during oocyte maturation. The CCR4-NOT complex is a major mammalian deadenylase, which regulates poly(A) tails of maternal mRNAs; however, the function of the CCR4-NOT complex in translational regulation has not been well understood. Here, we show that this complex suppresses translational activity of maternal mRNAs during oocyte maturation. Oocytes lacking all CCR4-NOT deadenylase activity owing to genetic deletion of its catalytic subunits, Cnot7 and Cnot8, showed a large-scale gene expression change caused by increased translational activity during oocyte maturation. Developmental arrest during meiosis I in these oocytes resulted in sterility of oocyte-specific Cnot7 and Cnot8 knockout female mice. We further showed that recruitment of CCR4-NOT to maternal mRNAs is mediated by the 3'UTR element CPE, which suppresses translational activation of maternal mRNAs. We propose that suppression of untimely translational activation of maternal mRNAs via deadenylation by CCR4-NOT is essential for proper oocyte maturation.

Pathogenic Mis-splicing of CPEB4 in Schizophrenia

BACKGROUND

Schizophrenia (SCZ) is caused by an interplay of polygenic risk and environmental factors, which may alter regulators of gene expression leading to pathogenic misexpression of SCZ risk genes. The CPEB family of RNA-binding proteins (CPEB1-4) regulates translation of target RNAs (approximately 40% of overall genes). We previously identified CPEB4 as a key dysregulated translational regulator in autism spectrum disorder (ASD) because its neuronal-specific microexon (exon 4) is mis-spliced in ASD brains, causing underexpression of numerous ASD risk genes. The genetic factors and pathogenic mechanisms shared between SCZ and ASD led us to hypothesize CPEB4 mis-splicing in SCZ leading to underexpression of multiple SCZ-related genes.

METHODS

We performed MAGMA-enrichment analysis on Psychiatric Genomics Consortium genome-wide association study data and analyzed RNA sequencing data from the PsychENCODE Consortium. Reverse transcriptase polymerase chain reaction and Western blot were performed on postmortem brain tissue, and the presence/absence of antipsychotics was assessed through toxicological analysis. Finally, mice with mild overexpression of exon 4-lacking CPEB4 (CPEB4Δ4) were generated and analyzed biochemically and behaviorally.

RESULTS

First, we found enrichment of SCZ-associated genes for CPEB4-binder transcripts. We also found decreased usage of CPEB4 microexon in SCZ probands, which was correlated with decreased protein levels of CPEB4-target SCZ-associated genes only in antipsychotic-free individuals. Interestingly, differentially expressed genes fit those reported for SCZ, specifically in the SCZ probands with decreased CPEB4-microexon inclusion. Finally, we demonstrated that mice with mild overexpression of CPEB4Δ4 showed decreased protein levels of CPEB4-target SCZ genes and SCZ-linked behaviors.

CONCLUSIONS

We identified aberrant CPEB4 splicing and downstream misexpression of SCZ risk genes as a novel etiological mechanism in SCZ.

Identification of novel genes associated with exercise and calorie restriction effects in skeletal muscle

Exercise and caloric restriction (CR) significantly increase longevity across a range of species and delay aging-related losses in organ function. Although both interventions enhance skeletal muscle function, the molecular mechanisms underlying these associations are unknown. We sought to identify genes regulated by CR and exercise in muscle, and investigate their relationship with muscle function. To do this, expression profiles of Gene Expression Omnibus datasets obtained from the muscle tissue of calorie-restricted male primates and young men post-exercise were analyzed. There were seven transcripts (ADAMTS1, CPEB4, EGR2, IRS2, NR4A1, PYGO1, and ZBTB43) that were consistently upregulated by both CR and exercise training. We used C2C12 murine myoblasts to investigate the effect of silencing these genes on myogenesis, mitochondrial respiration, autophagy, and insulin signaling, all of which are processes affected by CR and exercise. Our results show that in C2C12 cells, Irs2 and Nr4a1 expression were critical for myogenesis, and five genes (Egr2, Irs2, Nr4a1, Pygo1, and ZBTB43) regulated mitochondrial respiration while having no effect on autophagy. Cpeb4 knockdown increased the expression of genes involved in muscle atrophy and induced myotube atrophy. These findings suggest new resources for studying the mechanisms underlying the beneficial effects of exercise and calorie restriction on skeletal muscle function and lifespan extension.

Antitumor T-cell function requires CPEB4-mediated adaptation to chronic endoplasmic reticulum stress

Tumor growth is influenced by a complex network of interactions between multiple cell types in the tumor microenvironment (TME). These constrained conditions trigger the endoplasmic reticulum (ER) stress response, which extensively reprograms mRNA translation. When uncontrolled over time, chronic ER stress impairs the antitumor effector function of CD8 T lymphocytes. How cells promote adaptation to chronic stress in the TME without the detrimental effects of the terminal unfolded protein response (UPR) is unknown. Here, we find that, in effector CD8 T lymphocytes, RNA-binding protein CPEB4 constitutes a new branch of the UPR that allows cells to adapt to sustained ER stress, yet remains decoupled from the terminal UPR. ER stress, induced during CD8 T-cell activation and effector function, triggers CPEB4 expression. CPEB4 then mediates chronic stress adaptation to maintain cellular fitness, allowing effector molecule production and cytotoxic activity. Accordingly, this branch of the UPR is required for the antitumor effector function of T lymphocytes, and its disruption in these cells exacerbates tumor growth.

RNA binding proteins (RBPs) and their role in DNA damage and radiation response in cancer

Traditionally majority of eukaryotic gene expression is influenced by transcriptional and post-transcriptional events. Alterations in the expression of proteins that act post-transcriptionally can affect cellular signaling and homeostasis. RNA binding proteins (RBPs) are a family of proteins that specifically bind to RNAs and are involved in post-transcriptional regulation of gene expression and important cellular processes such as cell differentiation and metabolism. Deregulation of RNA-RBP interactions and any changes in RBP expression or function can lead to various diseases including cancer. In cancer cells, RBPs play an important role in regulating the expression of tumor suppressors and oncoproteins involved in various cell-signaling pathways. Several RBPs such as HuR, AUF1, RBM38, LIN28, RBM24, tristetrapolin family and Musashi play critical roles in various types of cancers and their aberrant expression in cancer cells makes them an attractive therapeutic target for cancer treatment. In this review we provide an overview of i). RBPs involved in cancer progression and their mechanism of action ii). the role of RBPs, including HuR, in breast cancer progression and DNA damage response and iii). explore RBPs with emphasis on HuR as therapeutic target for breast cancer therapy.

Inflammatory Bowel Disease Risk Variants Are Associated with an Increased Risk of Skin Cancer

BACKGROUND

Inflammatory bowel disease is associated with an increased risk of skin cancer. The aims of this study were to determine whether IBD susceptibility variants are also associated with skin cancer susceptibility and if such risk is augmented by use of immune-suppressive therapy.

METHODS

The discovery cohort included participants in the UK Biobank. The validation cohort included participants in the Michigan Genomics Initiative. The primary outcome of interest was skin cancer, subgrouped into nonmelanoma skin cancers (NMSC) and melanoma skin cancers (MSC). Multivariable logistic regression with matched controls (3 controls:1 case) was performed to identify genomic predictors of skin malignancy in the discovery cohort. Variants with P < .05 were tested for replication in the validation cohort. Validated Single nucleotide polymorphisms were then evaluated for effect modification by immune-suppressive medications.

RESULTS

The discovery cohort included 10,247 cases of NMSC and 1883 cases of MSC. The validation cohort included 7334 cases of NMSC and 3304 cases of MSC. Twenty-nine variants were associated with risk of NMSC in the discovery cohort, of which 5 replicated in the validation cohort (increased risk, rs7773324-A [DUSP22; IRF4], rs2476601-G [PTPN22], rs1847472-C [BACH2], rs72810983-A [CPEB4]; decreased risk, rs6088765-G [PROCR; MMP24]). Twelve variants were associated with risk of MSC in the discovery cohort, of which 4 were replicated in the validation cohort (increased risk, rs61839660-T [IL2RA]; decreased risk, rs17391694-C [GIPC2; MGC27382], rs6088765-G [PROCR; MMP24], and rs1728785-C [ZFP90]). No effect modification was observed.

CONCLUSIONS

The results of this study highlight shared genetic susceptibility across IBD and skin cancer, with increased risk of NMSC in those who carry risk variants in IRF4, PTPN22, CPEB4, and BACH2 and increased risk of MSC in those who carry a risk variant in IL2RA.

Targeting the "undruggable": RNA-binding proteins in the spotlight in cancer therapy

Tumors refractory to conventional therapy belong to specific subpopulations of cancer cells, which have acquired a higher number of mutations/epigenetic changes than the majority of cancer cells. This property provides them the ability to become resistant to therapy. Aberrant expression of certain RNA-binding proteins (RBPs) can regulate the sensitivity of tumor cells to chemotherapeutic drugs by binding to specific regions present in the 3´-UTR of certain mRNAs to promote or repress mRNA translation or by interacting with other proteins (including RBPs) and non-coding RNAs that are part of ribonucleoprotein complexes. In particular, an increasing interest in the RBPs involved in chemoresistance has recently emerged. In this review, we discuss how RBPs are not only affected by chemotherapeutic treatments, but also play an active role in therapeutic responses via the direct modulation of crucial cancer-related proteins. A special focus is being placed on the development of therapeutic strategies targeting these RBPs.

Control of immediate early gene expression by CPEB4-repressor complex-mediated mRNA degradation

BACKGROUND

Cytoplasmic polyadenylation element-binding protein 4 (CPEB4) is known to associate with cytoplasmic polyadenylation elements (CPEs) located in the 3' untranslated region (UTR) of specific mRNAs and assemble an activator complex promoting the translation of target mRNAs through cytoplasmic polyadenylation.

RESULTS

Here, we find that CPEB4 is part of an alternative repressor complex that mediates mRNA degradation by associating with the evolutionarily conserved CCR4-NOT deadenylase complex. We identify human CPEB4 as an RNA-binding protein (RBP) with enhanced association to poly(A) RNA upon inhibition of class I histone deacetylases (HDACs), a condition known to cause widespread degradation of poly(A)-containing mRNA. Photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation (PAR-CLIP) analysis using endogenously tagged CPEB4 in HeLa cells reveals that CPEB4 preferentially binds to the 3'UTR of immediate early gene mRNAs, at G-containing variants of the canonical U- and A-rich CPE located in close proximity to poly(A) sites. By transcriptome-wide mRNA decay measurements, we find that the strength of CPEB4 binding correlates with short mRNA half-lives and that loss of CPEB4 expression leads to the stabilization of immediate early gene mRNAs. Akin to CPEB4, we demonstrate that CPEB1 and CPEB2 also confer mRNA instability by recruitment of the CCR4-NOT complex.

CONCLUSIONS

While CPEB4 was previously known for its ability to stimulate cytoplasmic polyadenylation, our findings establish an additional function for CPEB4 as the RNA adaptor of a repressor complex that enhances the degradation of short-lived immediate early gene mRNAs.

Melanoma RBPome identification reveals PDIA6 as an unconventional RNA-binding protein involved in metastasis

RNA-binding proteins (RBPs) have been relatively overlooked in cancer research despite their contribution to virtually every cancer hallmark. Here, we use RNA interactome capture (RIC) to characterize the melanoma RBPome and uncover novel RBPs involved in melanoma progression. Comparison of RIC profiles of a non-tumoral versus a metastatic cell line revealed prevalent changes in RNA-binding capacities that were not associated with changes in RBP levels. Extensive functional validation of a selected group of 24 RBPs using five different in vitro assays unveiled unanticipated roles of RBPs in melanoma malignancy. As proof-of-principle we focused on PDIA6, an ER-lumen chaperone that displayed a novel RNA-binding activity. We show that PDIA6 is involved in metastatic progression, map its RNA-binding domain, and find that RNA binding is required for PDIA6 tumorigenic properties. These results exemplify how RIC technologies can be harnessed to uncover novel vulnerabilities of cancer cells.

Protein synthesis control in cancer: selectivity and therapeutic targeting

Translational control of mRNAs is a point of convergence for many oncogenic signals through which cancer cells tune protein expression in tumorigenesis. Cancer cells rely on translational control to appropriately adapt to limited resources while maintaining cell growth and survival, which creates a selective therapeutic window compared to non-transformed cells. In this review, we first discuss how cancer cells modulate the translational machinery to rapidly and selectively synthesize proteins in response to internal oncogenic demands and external factors in the tumor microenvironment. We highlight the clinical potential of compounds that target different translation factors as anti-cancer therapies. Next, we detail how RNA sequence and structural elements interface with the translational machinery and RNA-binding proteins to coordinate the translation of specific pro-survival and pro-growth programs. Finally, we provide an overview of the current and emerging technologies that can be used to illuminate the mechanisms of selective translational control in cancer cells as well as within the microenvironment.

RBM24 in the Post-Transcriptional Regulation of Cancer Progression: Anti-Tumor or Pro-Tumor Activity?

Simple Summary

RBM24 is a highly conserved RNA-binding protein that plays critical roles in the post-transcriptional regulation of gene expression for initiating cell differentiation during embryonic development and for maintaining tissue homeostasis in adult life. Evidence is now accumulating that it is frequently dysregulated across human cancers. Importantly, RBM24 may act as a tumor suppressor or as an oncogene in a context- or background-dependent manner. Its activity can be regulated by protein–protein interactions and post-translational modifications, making it a potential therapeutic target for cancer treatment. However, molecular mechanisms underlying its function in tumor growth and metastasis remain elusive. Further investigation will be necessary to better understand how its post-transcriptional regulatory activity is controlled and how it is implicated in tumor progression. This review provides a comprehensive analysis of recent findings on the implication of RBM24 in cancer and proposes future research directions to delve more deeply into the mechanisms underlying its tumor-suppressive function or oncogenic activity.

Abstract

RNA-binding proteins are critical post-transcriptional regulators of gene expression. They are implicated in a wide range of physiological and pathological processes by modulating nearly every aspect of RNA metabolisms. Alterations in their expression and function disrupt tissue homeostasis and lead to the occurrence of various cancers. RBM24 is a highly conserved protein that binds to a large spectrum of target mRNAs and regulates many post-transcriptional events ranging from pre-mRNA splicing to mRNA stability, polyadenylation and translation. Studies using different animal models indicate that it plays an essential role in promoting cellular differentiation during organogenesis and tissue regeneration. Evidence is also accumulating that its dysregulation frequently occurs across human cancers. In several tissues, RBM24 clearly functions as a tumor suppressor, which is consistent with its inhibitory potential on cell proliferation. However, upregulation of RBM24 in other cancers appears to promote tumor growth. There is a possibility that RBM24 displays both anti-tumor and pro-tumor activities, which may be regulated in part through differential interactions with its protein partners and by its post-translational modifications. This makes it a potential biomarker for diagnosis and prognosis, as well as a therapeutic target for cancer treatment. The challenge remains to determine the post-transcriptional mechanisms by which RBM24 modulates gene expression and tumor progression in a context- or background-dependent manner. This review discusses recent findings on the potential function of RBM24 in tumorigenesis and provides future directions for better understanding its regulatory role in cancer cells.

Immune translational control by CPEB4 regulates intestinal inflammation resolution and colorectal cancer development

Upon tissue injury, cytokine expression reprogramming transiently remodels the inflammatory immune microenvironment to activate repair processes and subsequently return to homeostasis. However, chronic inflammation induces permanent changes in cytokine production which exacerbate tissue damage and may even favor tumor development. Here, we address the contribution of post-transcriptional regulation, by the RNA-binding protein CPEB4, to intestinal immune homeostasis and its role in inflammatory bowel diseases (IBD) and colorectal cancer (CRC) development. We found that intestinal damage induces CPEB4 expression in adaptive and innate immune cells, which is required for the translation of cytokine mRNA(s) such as the one encoding interleukin-22. Accordingly, CPEB4 is required for the development of gut-associated lymphoid tissues and to maintain intestinal immune homeostasis, mediating repair and remodeling after acute inflammatory tissue damage and promoting the resolution of intestinal inflammation. CPEB4 is chronically overexpressed in inflammatory cells in patients with IBD and in CRC, favoring tumor development.

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CPEB4 is overexpressed in Th17 and ILC3 cells upon intestinal barrier damage

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CPEB4 is required for Il-22 mRNA translation and IL-22 expression

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CPEB4 promotes tissue repair in acute transient inflammation

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In chronic inflammation CPEB4 exacerbates intestinal pathology and promotes tumor growth

Development and Validation of Ten-RNA Binding Protein Signature Predicts Overall Survival in Osteosarcoma

Osteosarcoma is a malignant tumor that originates in the bones with the characteristics of high malignancy, predisposition to metastasis, and poor prognosis. RNA binding proteins (RBPs) are closely related to various tumors, but their relationship with osteosarcoma remains unclear. Based on GTEx and TARGET RNA sequencing data, we applied differential analysis to obtain RBP genes that are differentially expressed in osteosarcoma, and analyzed the functions of these RBPs. After applying univariate and LASSO Cox regression analysis, 10 key prognostic RBPs (TDRD6, TLR8, NXT2, EIF4E3, RPS27L, CPEB3, RBM34, TERT, RPS29, and ZC3HAV1) were screened, and an RBP prognostic risk assessment model for patients with osteosarcoma was established. The independent cohort GSE21257 was used for external verification, and the results showed that the signature has an excellent ability to predict prognosis. In addition, a nomogram that can be used for clinical evaluation was constructed. Finally, the expression levels of 10 prognostic RBPs in osteosarcoma cells and tissues were confirmed through experiments. Our study identified a ten-gene prognostic marker related to RBP, which is of great significance for adjusting the treatment strategy of patients with osteosarcoma and exploring prognostic markers.

CPEB4 Inhibit Cell Proliferation via Upregulating p21 mRNA Stability in Renal Cell Carcinoma

Cytoplasmic polyadenylation element-binding protein 4 (CPEB4) has been reported to be dysregulated in a variety of cancers and seems to play paradoxical roles in different cancers. However, the functional roles of CPEB4 in Renal cell carcinoma (RCC) are still unclear. This study aims to explore the role and underlying mechanism of CPEB4 in RCC. We found that the relative expression level of CPEB4 is down-regulated in RCC tissues and cell lines, and the low CPEB4 expression is correlated with short overall and disease-free survival of RCC patients. CPEB4 significantly inhibits RCC tumor growth both in vivo and in vitro. CPEB4 exerts an anti-tumor effect by increasing p21 mRNA stability and inducing G1 cell cycle arrest in RCC. Our data revealed that CPEB4 is a tumor suppressor gene that restrains cell cycle progression upstream of p21 in RCC. These findings revealed that CPEB4 may become a promising predictive biomarker for prognosis in patients with RCC.

Live imaging of neolymphangiogenesis identifies acute antimetastatic roles of dsRNA mimics

Long-range communication between tumor cells and the lymphatic vasculature defines competency for metastasis in different cancer types, particularly in melanoma. Nevertheless, the discovery of selective blockers of lymphovascular niches has been compromised by the paucity of experimental systems for whole-body analyses of tumor progression. Here, we exploit immunocompetent and immunodeficient mouse models for live imaging of Vegfr3-driven neolymphangiogenesis, as a versatile platform for drug screening in vivo. Spatiotemporal analyses of autochthonous melanomas and patient-derived xenografts identified double-stranded RNA mimics (dsRNA nanoplexes) as potent inhibitors of neolymphangiogenesis, metastasis, and post-surgical disease relapse. Mechanistically, dsRNA nanoplexes were found to exert a rapid dual action in tumor cells and in their associated lymphatic vasculature, involving the transcriptional repression of the lymphatic drivers Midkine and Vegfr3, respectively. This suppressive function was mediated by a cell-autonomous type I interferon signaling and was not shared by FDA-approved antimelanoma treatments. These results reveal an alternative strategy for targeting the tumor cell-lymphatic crosstalk and underscore the power of Vegfr3-lymphoreporters for pharmacological testing in otherwise aggressive cancers.

Targeting the cytoplasmic polyadenylation element-binding protein CPEB4 protects against diet-induced obesity and microbiome dysbiosis

Objective

Obesity represents a growing health problem that is reaching pandemic dimensions and lacks effective cures, thus highlighting an urgent need for better mechanistic understanding and new therapeutic strategies. Unlike transcription, the function of translation in obesity has hardly been investigated. Here, we fill this knowledge gap by pinpointing a crucial function for gene regulation at the step of translation in diet-induced obesity.

Methods

We performed studies with human adipose tissue, high-fat-diet-induced obese mice and rats, CPEB4-knockout mice, and adipocyte lines. Cells were transfected with small-interfering RNAs that knockdown CPEB4. Transcriptome-wide identification and validation of CPEB4 targets in adipocytes were obtained by RNA-protein coimmunoprecipitation and high-throughput sequencing. The effect of CPEB4 depletion on high-fat-diet-induced dysbiosis was determined by 16S ribosomal-RNA gene sequencing and microbiome bioinformatics.

Results

We show that cytoplasmic polyadenylation element-binding protein 4 (CPEB4), which controls the translation of specific mRNAs by modulating their poly(A) tails, is highly expressed in visceral fat of obese but not lean humans and rodents (mice and rats), where it orchestrates an essential post-transcriptional reprogramming for aggravation of high-fat-diet-induced obesity. Mechanistically, CPEB4 overexpression in obese adipocytes activates the translation of factors essential for adipose tissue expansion (Cebpb, Stat5a) and adipocyte-intrinsic immune-like potential (Ccl2, Tlr4), as demonstrated by RNA-immunoprecipitation and high-throughput sequencing and experimentally validated in vivo. Consistently blocking CPEB4 production in knockout mice protects against diet-induced body weight gain and reduces adipose tissue enlargement and inflammation. In addition, the depletion of CPEB4 specifically in obese adipocytes using short hairpin RNAs decreases cell differentiation, lipid accumulation, and the proinflammatory and migratory capacity of macrophages. The absence of CPEB4 also attenuates high-fat diet-induced dysbiosis, shaping the microbiome composition toward a more beneficial profile, as shown by microbiome bioinformatics analysis.

Conclusion

Our study identifies CPEB4 as a driver and therapeutic target to combat obesity.

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CPEB4 expression is elevated in adipose tissue from obese patients and rodents.

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CPEB4 overexpression is required for the abnormal obesity-associated phenotype.

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Targeting CPEB4 reduces predisposition to diet-induced obesity.

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Targeting CPEB4 alleviates obesity-associated microbiome dysbiosis.

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CPEB4 is an attractive therapeutic target for treating obesity and its sequelae.

CPEB alteration and aberrant transcriptome-polyadenylation lead to a treatable SLC19A3 deficiency in Huntington's disease

[Figure: see text].

The oncogenic and tumor suppressive roles of RNA-binding proteins in human cancers

Posttranscriptional regulation is a mechanism for the cells to control gene regulation at the RNA level. In this process, RNA-binding proteins (RBPs) play central roles and orchestrate the function of RNA molecules in multiple steps. Accumulating evidence has shown that the aberrant regulation of RBPs makes  contributions to the initiation and progression of tumorigenesis via numerous mechanisms such as genetic changes, epigenetic alterations, and noncoding RNA-mediated regulations. In this article, we review the effects caused by RBPs and their functional diversity in the malignant transformation of cancer cells that occurs through the involvement of these proteins in various stages of RNA regulation including alternative splicing, stability, polyadenylation, localization, and translation. Besides this, we review the various interactions between RBPs and other crucial posttranscriptional regulators such as microRNAs and long noncoding RNAs in the pathogenesis of cancer. Finally, we discuss the potential approaches for targeting RBPs in human cancers.

Transcriptome Analyses Identify an RNA Binding Protein Related Prognostic Model for Clear Cell Renal Cell Carcinoma

RNA binding proteins (RBPs) play a key role in post-transcriptional gene regulation. They have been shown to be dysfunctional in a variety of cancers and are closely related to the occurrence and progression of cancers. However, the biological function and clinical significance of RBPs in clear cell renal carcinoma (ccRCC) are unclear. In our current study, we downloaded the transcriptome data of ccRCC patients from The Cancer Genome Atlas (TCGA) database and identified differential expression of RBPs between tumor tissue and normal kidney tissue. Then the biological function and clinical value of these RBPs were explored by using a variety of bioinformatics techniques. We identified a total of 40 differentially expressed RBPs, including 10 down-regulated RBPs and 30 up-regulated RBPs. Eight RBPs (APOBEC3G, AUH, DAZL, EIF4A1, IGF2BP3, NR0B1, RPL36A, and TRMT1) and nine RBPs (APOBEC3G, AUH, DDX47, IGF2BP3, MOV10L1, NANOS1, PIH1D3, TDRD9, and TRMT1) were identified as prognostic related to overall survival (OS) and disease-free survival (DFS), respectively, and prognostic models for OS and DFS were constructed based on these RBPs. Further analysis showed that OS and DFS were worse in high-risk group than in the low-risk group. The area under the receiver operator characteristic curve of the model for OS was 0.702 at 3 years and 0.726 at 5 years in TCGA cohort and 0.783 at 3 years and 0.795 at 5 years in E-MTAB-1980 cohort, showing good predictive performance. Both models have been shown to independently predict the prognosis of ccRCC patients. We also established a nomogram based on these prognostic RBPs for OS and performed internal validation in the TCGA cohort, showing an accurate prediction of ccRCC prognosis. Stratified analysis showed a significant correlation between the prognostic model for OS and ccRCC progression.

mRNA spindle localization and mitotic translational regulation by CPEB1 and CPEB4

Transition through cell cycle phases requires temporal and spatial regulation of gene expression to ensure accurate chromosome duplication and segregation. This regulation involves dynamic reprogramming of gene expression at multiple transcriptional and posttranscriptional levels. In transcriptionally silent oocytes, the CPEB-family of RNAbinding proteins coordinates temporal and spatial translation regulation of stored maternal mRNAs to drive meiotic progression. CPEB1 mediates mRNA localization to the meiotic spindle, which is required to ensure proper chromosome segregation. Temporal translational regulation also takes place in mitosis, where a large repertoire of transcripts are activated or repressed in specific cell cycle phases. However, whether control of localized translation at the spindle is required for mitosis is unclear, as mitotic and acentriolar-meiotic spindles are functionally and structurally different. Furthermore, the large differences in scale-ratio between cell volume and spindle size in oocytes compared to somatic mitotic cells may generate distinct requirements for gene expression compartmentalization in meiosis and mitosis. Here we show that mitotic spindles contain CPE-localized mRNAs and translating ribosomes. Moreover, CPEB1 and CPEB4 localize in the spindles and they may function sequentially in promoting mitotic stage transitions and correct chromosome segregation. Thus, CPEB1 and CPEB4 bind to specific spindle-associated transcripts controlling the expression and/or localization of their encoded factors that, respectively, drive metaphase and anaphase/cytokinesis.

Molecular Characterization and Clinical Relevance of RNA Binding Proteins in Colorectal Cancer

Abnormal expression of RNA binding proteins (RBPs) has been reported across various cancers. However, the potential role of RBPs in colorectal cancer (CRC) remains unclear. In this study, we performed a systematic bioinformatics analysis of RBPs in CRC. We downloaded CRC data from The Cancer Genome Atlas (TCGA) database. Our analysis identified 242 differentially expressed RBPs between tumor and normal tissues, including 200 upregulated and 42 downregulated RBPs. Next, we found eight RBPs (RRS1, PABPC1L, TERT, SMAD6, UPF3B, RP9, NOL3, and PTRH1) related to the prognoses of CRC patients. Among these eight prognosis-related RBPs, four RBPs (NOL3, PTRH1, UPF3B, and SMAD6) were selected to construct a prognostic risk score model. Furthermore, our results indicated that the prognostic risk score model accurately predicted the prognosis of CRC patients [area under the receiver operating characteristic curve (AUC)for 3- and 5-year overall survival (OS) and was 0.645 and 0.672, respectively]. Furthermore, we developed a nomogram based on a prognostic risk score model. The nomogram was able to demonstrate the wonderful performance in predicting 3- and 5-year OS. Additionally, we validated the clinical value of four risk genes in the prognostic risk score model and identified that these risk genes were associated with tumorigenesis, lymph node metastasis, distant metastasis, clinical stage, and prognosis. Finally, we used the TIMER and Human Protein Atlas (HPA)database to validate the expression of four risk genes at the transcriptional and translational levels, respectively, and used a clinical cohort to validate the roles of NOL3 and UPF3B in predicting the prognosis of CRC patients. In summary, our study demonstrated that RBPs have an effect on CRC tumor progression and might be potential prognostic biomarkers for CRC patients.

CPEB3-mediated MTDH mRNA translational suppression restrains hepatocellular carcinoma progression

Cytoplasmic polyadenylation element-binding protein 3 (CPEB3) is a sequence-specific RNA-binding protein. We had reported that CPEB3 is involved in hepatocellular carcinoma (HCC) progression. However, the underlying mechanisms of CPEB3 in HCC remain unclear. In this study, we firstly performed RNA immunoprecipitation to uncover the transcriptome-wide CPEB3-bound mRNAs (CPEB3 binder) in HCC. Bioinformatic analysis indicates that CPEB3 binders are closely related to cancer progression, especially HCC metastasis. Further studies confirmed that metadherin (MTDH) is a direct target of CPEB3. CPEB3 can suppress the translation of MTDH mRNA in vivo and in vitro. Besides, luciferase assay demonstrated that CPEB3 interacted with 3'-untranslated region of MTDH mRNA and inhibited its translation. Subsequently, CPEB3 inhibited the epithelial-mesenchymal transition and metastasis of HCC cells through post-transcriptional regulation of MTDH. In addition, cpeb3 knockout mice are more susceptible to carcinogen-induced hepatocarcinogenesis and subsequent lung metastasis. Our results also indicated that CPEB3 was a good prognosis marker, which is downregulated in HCC tissue. In conclusion, our results demonstrated that CPEB3 played an important role in HCC progression and targeting CPEB3-mediated mRNA translation might be a favorable therapeutic approach.

RNA-Binding Proteins in Cancer: Functional and Therapeutic Perspectives

Simple Summary

RNA-binding proteins (RBPs) play central roles in regulating posttranscriptional expression of genes. Many of them are known to be deregulated in a wide variety of cancers. Dysregulated RBPs influence the expression levels of target RNAs related to cancer phenotypes, such as proliferation, apoptosis, angiogenesis, senescence, and EMT/invasion/metastasis. Thus, understanding the molecular functions of RBPs and their roles in cancer-related phenotypes can lead to improved therapeutic strategies.

Abstract

RNA-binding proteins (RBPs) crucially regulate gene expression through post-transcriptional regulation, such as by modulating microRNA (miRNA) processing and the alternative splicing, alternative polyadenylation, subcellular localization, stability, and translation of RNAs. More than 1500 RBPs have been identified to date, and many of them are known to be deregulated in cancer. Alterations in the expression and localization of RBPs can influence the expression levels of oncogenes, tumor-suppressor genes, and genome stability-related genes. RBP-mediated gene regulation can lead to diverse cancer-related cellular phenotypes, such as proliferation, apoptosis, angiogenesis, senescence, and epithelial-mesenchymal transition (EMT)/invasion/metastasis. This regulation can also be associated with cancer prognosis. Thus, RBPs can be potential targets for the development of therapeutics for the cancer treatment. In this review, we describe the molecular functions of RBPs, their roles in cancer-related cellular phenotypes, and various approaches that may be used to target RBPs for cancer treatment.

RNA-binding proteins in tumor progression

RNA-binding protein (RBP) has a highly dynamic spatiotemporal regulation process and important biological functions. They are critical to maintain the transcriptome through post-transcriptionally controlling the processing and transportation of RNA, including regulating RNA splicing, polyadenylation, mRNA stability, mRNA localization, and translation. Alteration of each process will affect the RNA life cycle, produce abnormal protein phenotypes, and thus lead to the occurrence and development of tumors. Here, we summarize RBPs involved in tumor progression and the underlying molecular mechanisms whereby they are regulated and exert their effects. This analysis is an important step towards the comprehensive characterization of post-transcriptional gene regulation involved in tumor progression.

Chondroitin polymerizing factor (CHPF) promotes development of malignant melanoma through regulation of CDK1

Chondroitin polymerizing factor (CHPF) is an important member of glycosyltransferases involved in the biosynthesis of chondroitin sulfate (CS). However, the relationship between CHPF and malignant melanoma (MM) is still unknown. In this study, it was demonstrated that CHPF was up-regulated in MM tissues compared with the adjacent normal skin tissues and its high expression was correlated with more advanced T stage. Further investigations indicated that the over-expression/knockdown of CHPF could promote/inhibit proliferation, colony formation and migration of MM cells, while inhibiting/promoting cell apoptosis. Moreover, knockdown of CHPF could also suppress tumorigenicity of MM cells in vivo. RNA-sequencing followed by Ingenuity pathway analysis (IPA) was performed for exploring downstream of CHPF and identified CDK1 as the potential target. Furthermore, our study revealed that knockdown of CDK1 could inhibit development of MM in vitro, and alleviate the CHPF over-expression induced promotion of MM. In conclusion, our study showed, as the first time, CHPF as a tumor promotor for MM, whose function was carried out probably through the regulation of CDK1.

NFE2L1 and NFE2L3 Complementarily Maintain Basal Proteasome Activity in Cancer Cells through CPEB3-Mediated Translational Repression

Proteasomes are protease complexes essential for cellular homeostasis, and their activity is crucial for cancer cell growth. However, the mechanism of how proteasome activity is maintained in cancer cells has remained unclear. The CNC family transcription factor NFE2L1 induces the expression of almost all proteasome-related genes under proteasome inhibition. Both NFE2L1 and its phylogenetically closest homolog, NFE2L3, are highly expressed in several types of cancer, such as colorectal cancer. Here, we demonstrate that NFE2L1 and NFE2L3 complementarily maintain basal proteasome activity in cancer cells. Double knockdown of NFE2L1 and NFE2L3 impaired basal proteasome activity in cancer cells and cancer cell resistance to a proteasome inhibitor anticancer drug, bortezomib, by significantly reducing the basal expression of seven proteasome-related genes: PSMB3, PSMB7, PSMC2, PSMD3, PSMG2, PSMG3, and POMP Interestingly, the molecular basis behind these cellular consequences was that NFE2L3 repressed NFE2L1 translation by the induction of the gene encoding the translational regulator CPEB3, which binds to the NFE2L1 3' untranslated region and decreases polysome formation on NFE2L1 mRNA. Consistent results were obtained from clinical analysis, wherein patients with cancer having tumors expressing higher levels of CPEB3/NFE2L3 exhibit poor prognosis. These results provide the novel regulatory mechanism of basal proteasome activity in cancer cells through an NFE2L3-CPEB3-NFE2L1 translational repression axis.

Emerging Roles of RNA 3'-end Cleavage and Polyadenylation in Pathogenesis, Diagnosis and Therapy of Human Disorders

A crucial feature of gene expression involves RNA processing to produce 3′ ends through a process termed 3′ end cleavage and polyadenylation (CPA). This ensures the nascent RNA molecule can exit the nucleus and be translated to ultimately give rise to a protein which can execute a function. Further, alternative polyadenylation (APA) can produce distinct transcript isoforms, profoundly expanding the complexity of the transcriptome. CPA is carried out by multi-component protein complexes interacting with multiple RNA motifs and is tightly coupled to transcription, other steps of RNA processing, and even epigenetic modifications. CPA and APA contribute to the maintenance of a multitude of diverse physiological processes. It is therefore not surprising that disruptions of CPA and APA can lead to devastating disorders. Here, we review potential CPA and APA mechanisms involving both loss and gain of function that can have tremendous impacts on health and disease. Ultimately we highlight the emerging diagnostic and therapeutic potential CPA and APA offer.

Cancer the'RBP'eutics-RNA-binding proteins as therapeutic targets for cancer

RNA-binding proteins (RBPs) play a critical role in the regulation of various RNA processes, including splicing, cleavage and polyadenylation, transport, translation and degradation of coding RNAs, non-coding RNAs and microRNAs. Recent studies indicate that RBPs not only play an instrumental role in normal cellular processes but have also emerged as major players in the development and spread of cancer. Herein, we review the current knowledge about RNA binding proteins and their role in tumorigenesis as well as the potential to target RBPs for cancer therapeutics.

MITF-the first 25 years

In this review, Goding and Arnheiter present the current understanding of MITF's role and regulation in development and disease and highlight key areas where our knowledge of MITF regulation and function is limited.

All transcription factors are equal, but some are more equal than others. In the 25 yr since the gene encoding the microphthalmia-associated transcription factor (MITF) was first isolated, MITF has emerged as a key coordinator of many aspects of melanocyte and melanoma biology. Like all transcription factors, MITF binds to specific DNA sequences and up-regulates or down-regulates its target genes. What marks MITF as being remarkable among its peers is the sheer range of biological processes that it appears to coordinate. These include cell survival, differentiation, proliferation, invasion, senescence, metabolism, and DNA damage repair. In this article we present our current understanding of MITF's role and regulation in development and disease, as well as those of the MITF-related factors TFEB and TFE3, and highlight key areas where our knowledge of MITF regulation and function is limited.

Altered expression pattern of circular RNAs in metastatic oral mucosal melanoma

Circular RNAs (circRNAs) are known to be associated with carcinogenesis, and can serve as potential biomarkers for cancer diagnosis and therapeutic implications. However, little is known about their expression patterns in oral mucosal melanoma (OMM), an extremely rare cancer that is distinct from cutaneous melanoma for its clinical course and prognosis. To investigate circRNAs expression profile in OMM, we performed a circRNAs microarray to analyze 6 primary OMM samples with lymph nodes dissemination, and constructed a genome-wide circRNA profile. Our results revealed that 90 circRNAs were significantly dysregulated in the metastatic OMM tissues when compared to the paired adjacent tissues. Among them, hsa_circ_0005320, hsa_circ_0067531, hsa_circ_0008042 were significantly upregulated in primary tumor and metastatic lymph nodes compared to paired adjacent normal tissues and non-metastatic lymph nodes, whereas the expression of hsa_circ_0000869 and hsa_circ_0000853 were downregulated relatively. Gene Ontology (GO) and pathway analyses of differentially expressed circRNAs indicated that these identified circRNAs might play important roles in protein modification, protein binding and cellular metabolism in metastatic OMM. Functions of several selected circRNA were also identified. In addition, by using bioinformatics predictions, we further demonstrated that hsa_circ_0005320, hsa_circ_0067531 and hsa_circ_0000869 could serve as competing endogenous RNA (ceRNA), which might regulate tumorigenesis and metastatic of OMM by binding to specific microRNAs. Our results not only suggested that circRNAs might play critical roles in metastasis of OMM, but also provided critical information of circRNAs in regulating OMM progression. The findings would help us to develop potential biomarkers for clinical diagnosis and design therapeutic strategies for OMM.

Analysis of protein-protein interaction network based on transcriptome profiling of ovine granulosa cells identifies candidate genes in cyclic recruitment of ovarian follicles

After pubertal, cohort of small antral follicles enters to gonadotrophin-sensitive development, called recruited follicles. This study was aimed to identify candidate genes in follicular cyclic recruitment via analysis of protein-protein interaction (PPI) network. Differentially expressed genes (DEGs) in ovine granulosa cells of small antral follicles between follicular and luteal phases were accumulated among gene/protein symbols of the Ensembl annotation. Following directed graphs, PTPN6 and FYN have the highest indegree and outdegree, respectively. Since, these hubs being up-regulated in ovine granulosa cells of small antral follicles during the follicular phase, it represents an accumulation of blood immune cells in follicular phase in comparison with luteal phase. By contrast, the up-regulated hubs in the luteal phase including CDK1, INSRR and TOP2A which stimulated DNA replication and proliferation of granulosa cells, they known as candidate genes of the cyclic recruitment.

CPEB4 regulates glioblastoma cell proliferation and predicts poor outcome of patients

OBJECTIVE

Cytoplasmic polyadenylation element binding protein 4 (CPEB4) is a regulator of gene expression at transcriptional level and has been reported to be associated with biological malignancy in cancers. However, little was known about the correlation between CPEB4 and glioblastoma cell proliferation and the prognostic significance in patients. Our aim was to investigate the functional role and prognostic value of CPEB4 in glioblastoma.

PATIENTS AND METHODS

We determined the expression of CPEB4 protein using immunohistochemistry in tissue microarrays containing 278 glioma patients (including 98 primary glioblastomas) and evaluated its association with pathological grades and clinical outcome by univariate and multivariate analyses. And then, lentiviral-mediated RNAi targeting CPEB4 was utilized to study the role of CPEB4 in glioblastoma cell proliferation.

RESULTS

In our cohort, CPEB4 expression was positively related to glioma pathological grade (p < 0.01) and elevated in glioblastoma (p < 0.01). High expression of CPEB4 was associated with significantly poor prognosis, and could be identified as an independent risk factor for overall survival (OS) and progression-free survival (PFS) of glioblastoma patients (hazard ratio (HR) = 1.730, p = 0.014 and HR = 1.877, p = 0.004, respectively). In vitro studies further showed that downregulation of CPEB4 significantly reduced the growth rate of T98G and U251 cells comparing with the controls.

CONCLUSION

Our study indicated that increased expression of CPEB4 in primary glioblastoma is a novel biomarker for predicting poor outcome of patients and suppression of CPEB4 inhibit tumor cell proliferation, suggesting a potential therapeutic target for glioblastoma.

Systems analysis identifies melanoma-enriched pro-oncogenic networks controlled by the RNA binding protein CELF1

Melanomas are well-known for their altered mRNA expression profiles. Yet, the specific contribution of mRNA binding proteins (mRBPs) to melanoma development remains unclear. Here we identify a cluster of melanoma-enriched genes under the control of CUGBP Elav-like family member 1 (CELF1). CELF1 was discovered with a distinct prognostic value in melanoma after mining the genomic landscape of the 692 known mRBPs across different cancer types. Genome-wide transcriptomic, proteomic, and RNA-immunoprecipitation studies, together with loss-of-function analyses in cell lines, and histopathological evaluation in clinical biopsies, revealed an intricate repertoire of CELF1-RNA interactors with minimal overlap with other malignancies. This systems approach uncovered the oncogene DEK as an unexpected target and downstream effector of CELF1. Importantly, CELF1 and DEK were found to represent early-induced melanoma genes and adverse indicators of overall patient survival. These results underscore novel roles of CELF1 in melanoma, illustrating tumor type-restricted functions of RBPs in cancer.

TYRP1 mRNA goes fishing for miRNAs in melanoma

A variety of non-coding RNAs have been reported as endogenous sponges for cancer-modulating miRNAs. However, miRNA trapping by transcripts with protein-coding functions is less understood. The mRNA of TYRP1 is now found to sequester the tumour suppressor miR-16 on non-canonical miRNA response elements in melanoma, thereby promoting malignant growth.

Translational Dysregulation in Cancer: Molecular Insights and Potential Clinical Applications in Biomarker Development

Although transcript levels have been traditionally used as a surrogate measure of gene expression, it is increasingly recognized that the latter is extensively and dynamically modulated at the level of translation (messenger RNA to protein). Over the recent years, significant progress has been made in dissecting the complex posttranscriptional mechanisms that regulate gene expression. This advancement in knowledge came hand in hand with the progress made in the methodologies to study translation both at gene-specific as well as global genomic level. The majority of translational control is exerted at the level of initiation; nonetheless, protein synthesis can be modulated at the level of translation elongation, termination, and recycling. Sequence and structural elements and epitranscriptomic modifications of individual transcripts allow for dynamic gene-specific modulation of translation. Cancer cells usurp the regulatory mechanisms that govern translation to carry out translational programs that lead to the phenotypic hallmarks of cancer. Translation is a critical nexus in neoplastic transformation. Multiple oncogenes and signaling pathways that are activated, upregulated, or mutated in cancer converge on translation and their transformative impact "bottlenecks" at the level of translation. Moreover, this translational dysregulation allows cancer cells to adapt to a diverse array of stresses associated with a hostile microenviroment and antitumor therapies. All elements involved in the process of translation, from the transcriptional template, the components of the translational machinery, to the proteins that interact with the transcriptome, have been found to be qualitatively and/or quantitatively perturbed in cancer. This review discusses the regulatory mechanisms that govern translation in normal cells and how translation becomes dysregulated in cancer leading to the phenotypic hallmarks of malignancy. We also discuss how dysregulated mediators or components of translation can be utilized as biomarkers with potential diagnostic, prognostic, or predictive significance. Such biomarkers have the potential advantage of uniform applicability in the face of inherent tumor heterogeneity and deoxyribonucleic acid instability. As translation becomes increasingly recognized as a process gone awry in cancer and agents are developed to target it, the utility and significance of these potential biomarkers is expected to increase.

RNA-Binding Proteins in Cancer: Old Players and New Actors

RNA-binding proteins (RBPs) are key players in post-transcriptional events. The combination of versatility of their RNA-binding domains with structural flexibility enables RBPs to control the metabolism of a large array of transcripts. Perturbations in RBP-RNA networks activity have been causally associated with cancer development, but the rational framework describing these contributions remains fragmented. We review here the evidence that RBPs modulate multiple cancer traits, emphasize their functional diversity, and assess future trends in the study of RBPs in cancer.

CPEB4 promotes cell migration and invasion via upregulating Vimentin expression in breast cancer

Cytoplasmic polyadenylation element binding protein 4 (CPEB4) is a member of CPEB family which is overexpressed in variety of cancers. However, the biological role and regulatory mechanism of CPEB4 in cancers remain unknown. Here, we first investigate the role of CPEB4 in breast cancer progression and metastasis. The expression of CPEB4 is elevated in breast cancer tissues compared with adjacent normal tissues. Furthermore, high expression levels of CPEB4 is associated with tumor metastasis in breast cancer patients. Ectopic expression of CPEB4 dramatically promotes EMT, migration and invasion of breast cancer cells, while silencing CPEB4 expression significantly reduces these events. Mechanically, overexpression of CPEB4 upregulates Vimentin expression and silencing Vimentin expression blocks CPEB4-induced migration and invasion of breast cancer cells. These results implicate the potential role of CPEB4 and Vimentin in breast cancer metastasis, which is further confirmed by the finding that there is a physical interaction between the two proteins. Altogether, our results provide a novel insight into CPEB4 in regulating breast cancer progression and metastasis.