Ubiquitin-specific protease 5 promotes bladder cancer progression through stabilizing Twist1

Aberrant activation of the epithelial-mesenchymal transition (EMT) pathway drives the development of solid tumors, which is precisely regulated by core EMT-related transcription factors, including Twist1. However, the expression pattern and regulatory mechanism of Twist1 in the progression of bladder cancer is still unclear. In this study, we explore the role of Twist1 in the progression of bladder cancer. We discovered that the EMT regulon Twist1 protein, but not Twist1 mRNA, is overexpressed in bladder cancer samples using RT-qPCR, western blot and immunohistochemistry (IHC). Mechanistically, co-immunoprecipitation (Co-IP) coupled with liquid chromatography and tandem mass spectrometry identified USP5 as a binding partner of Twist1, and the binding of Twist1 to ubiquitin-specific protease 5 (USP5) stabilizes Twist through its deubiquitinase activity to activate the EMT. Further studies found that USP5 depletion reduces cell proliferation, invasion and the EMT in bladder cancer cells, and ectopic expression of Twist1 rescues the adverse effects of USP5 loss on cell invasion and the EMT. A xenograft tumor model was used to reconfirmed the inhibitor effect of silencing USP5 expression on tumorigenesis in vivo. In addition, USP5 protein levels are significantly elevated and positively associated with Twist1 levels in clinical bladder cancer samples. Collectively, our study revealed that USP5-Twist1 axis is a novel regulatory mechanism driving bladder cancer progression and that approaches targeting USP5 may become a promising cancer treatment strategy.

The Ubiquitin-like Proteins of Saccharomyces cerevisiae

In this review, we present a comprehensive list of the ubiquitin-like modifiers (Ubls) of Saccharomyces cerevisiae, a common model organism used to study fundamental cellular processes that are conserved in complex multicellular organisms, such as humans. Ubls are a family of proteins that share structural relationships with ubiquitin, and which modify target proteins and lipids. These modifiers are processed, activated and conjugated to substrates by cognate enzymatic cascades. The attachment of substrates to Ubls alters the various properties of these substrates, such as function, interaction with the environment or turnover, and accordingly regulate key cellular processes, including DNA damage, cell cycle progression, metabolism, stress response, cellular differentiation, and protein homeostasis. Thus, it is not surprising that Ubls serve as tools to study the underlying mechanism involved in cellular health. We summarize current knowledge on the activity and mechanism of action of the S. cerevisiae Rub1, Smt3, Atg8, Atg12, Urm1 and Hub1 modifiers, all of which are highly conserved in organisms from yeast to humans.

The biological function of metazoan-specific subunit nuclear factor related to kappaB binding protein of INO80 complex

The INO80 chromatin remodeling complex plays an essential role in the regulation of gene transcription, which participate in a variety of important biological processes in cells including DNA repair and DNA replication. Difference from the yeast INO80 complex, metazoan INO80 complex have the specific subunit G, which is known as nuclear factor related to kappaB binding protein (NFRKB). Recently, NFRKB has been received much attention in many aspects, such as DNA repair, cell pluripotency, telomere protection, and protein activity regulation. To dig the new function of metazoan INO80 complex, a better understanding of the role of NFRKB is required. In this review, we provide an overview of the structure and function of NFRKB and discuss its potential role in cancer treatment and telomere regulation. Overall, this review provides an important reference for further research of the INO80 complex and NFRKB.

Exploring the Molecular Mechanism of lncRNA-miRNA-mRNA Networks in Non-Syndromic Cleft Lip with or without Cleft Palate

Background

Non-syndromic cleft lip with or without cleft palate (NSCL/P) is a common craniofacial birth defect. Growing evidence has demonstrated the competing endogenous RNA (ceRNA) hypothesis has played a role in the pathogenesis of NSCL/P. Here, we identified the important lncRNAs in NSCL/P and constructed a ceRNA regulatory network to predict their underlying functional mechanism.

Methods

Total RNA isolated from the peripheral blood samples were analyzed by the Human Clariom D Affymetrix platform and differentially expressed genes (DEGs) were identified. Using the limma package in R software, DEGs in the expression profile of GSE42589 were identified from Gene Expression Omnibus (GEO) database. Co-differentially expressed lncRNAs (co-DElncRNAs) were used to predict the microRNAs that may bind to them. Co-differentially expressed mRNAs (co-DEmRNAs) were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. The hub genes were screened using the cytohubba plug-in in Cytoscape. A ceRNA network was built to investigate the molecular mechanism underlying the etiology of NSCL/P. The expression levels of lncRNAs, miRNAs, and mRNAs in the network were assessed by quantitative real-time polymerase chain reaction (qRT-PCR).

Results

We found 116 DElncRNAs and 2955 DEmRNAs from the GSE42589 dataset, and 2626 DElncRNAs and 2771 DEmRNAs from the Human Clariom D gene chip. A network of co-DEmRNAs containing 3712 edges and 621 nodes were identified by PPI analysis. A ceRNA regulatory network comprising lncRNA USP17L6P, hsa-miR-449c-5p, and MYC was established. qRT-PCR results revealed significantly lower expression levels of lncRNA USP17L6P and c-Myc in NSCL/P tissues, while the expression level of hsa-miR-449c-5p was higher as compared to control samples (p < 0.05).

Conclusion

The identified lncRNAs and the established ceRNA regulatory network provide novel insight into the pathogenesis of NSCL/P, therefore hold great promise in NSCL/P management in clinical practice.

Ubiquitin-Specific Proteases: Players in Cancer Cellular Processes

Ubiquitination represents a post-translational modification (PTM) essential for the maintenance of cellular homeostasis. Ubiquitination is involved in the regulation of protein function, localization and turnover through the attachment of a ubiquitin molecule(s) to a target protein. Ubiquitination can be reversed through the action of deubiquitinating enzymes (DUBs). The DUB enzymes have the ability to remove the mono- or poly-ubiquitination signals and are involved in the maturation, recycling, editing and rearrangement of ubiquitin(s). Ubiquitin-specific proteases (USPs) are the biggest family of DUBs, responsible for numerous cellular functions through interactions with different cellular targets. Over the past few years, several studies have focused on the role of USPs in carcinogenesis, which has led to an increasing development of therapies based on USP inhibitors. In this review, we intend to describe different cellular functions, such as the cell cycle, DNA damage repair, chromatin remodeling and several signaling pathways, in which USPs are involved in the development or progression of cancer. In addition, we describe existing therapies that target the inhibition of USPs.

Overexpression of NuSAP1 is predictive of an unfavourable prognosis and promotes proliferation and invasion of triple-negative breast cancer cells via the Wnt/β-catenin/EMT signalling axis

OBJECTIVE

We analysed the effect of expression of nucleolar spindle-associated protein 1 (NuSAP1) on the prognosis of breast cancer (BC) and investigated its potential mechanism of tumourigenicity in triple-negative breast cancer (TNBC) cell lines.

MATERIALS AND METHODS

We downloaded the RNA-seq breast cancer (BC) data from The Cancer Genome Atlas (TCGA) and screened for the NuSAP1 gene using R software. The clinical data for patients with BC were screened and analysed using R software. A survival curve was drawn using the Kaplan-Meier Plotter. Cell proliferation and invasion were verified by the Cell Counting Kit-8 and Transwell assays. Expression of NuSAP1, the Wnt/β-catenin pathway, and epithelial-mesenchymal-transition-related proteins in TNBC was detected using real-time quantitative polymerase chain reaction (qRT-PCR) and western blotting (WB).

RESULTS

Expression of NuSAP1 was upregulated in BC. The change in NuSAP1 expression levels was associated with multiple clinicopathological factors, and the higher the expression of NuSAP1 was, the shorter the survival time. In MDA-MB-231 and BT549 cells, knockdown of NuSAP1 expression resulted in a significant decrease in cell proliferation and invasion; a decrease in expression of cyclin D1, vimentin, Slug, Twist, wnt3a, and pβ-catenin; and an increase in expression of e-cadherin. The results of the sh-NuSAP1 + ov-NuSPA1 group were the opposite of the results of the sh-NuSAP1 group.

CONCLUSION

NuSAP1 is a carcinogen that facilitates progression of TNBC through the Wnt/β-catenin and epithelial-mesenchymal transition pathways.

Oncogenic functions of the EMT-related transcription factor ZEB1 in breast cancer

Zinc finger E-box binding homeobox 1 (ZEB1, also termed TCF8 and δEF1) is a crucial member of the zinc finger-homeodomain transcription factor family, originally identified as a binding protein of the lens-specific δ1-crystalline enhancer and is a pivotal transcription factor in the epithelial-mesenchymal transition (EMT) process. ZEB1 also plays a vital role in embryonic development and cancer progression, including breast cancer progression. Increasing evidence suggests that ZEB1 stimulates tumor cells with mesenchymal traits and promotes multidrug resistance, proliferation, and metastasis, indicating the importance of ZEB1-induced EMT in cancer development. ZEB1 expression is regulated by multiple signaling pathways and components, including TGF-β, β-catenin, miRNA and other factors. Here, we summarize the recent discoveries of the functions and mechanisms of ZEB1 to understand the role of ZEB1 in EMT regulation in breast cancer.