Furry protein suppresses nuclear localization of yes-associated protein (YAP) by activating NDR kinase and binding to YAP

Dopey-dependent regulation of extracellular vesicles maintains neuronal morphology

Mature neurons maintain their distinctive morphology for extended periods in adult life. Compared to developmental neurite outgrowth, axon guidance, and target selection, relatively little is known of mechanisms that maintain mature neuron morphology. Loss of function in C. elegans DIP-2, a member of the conserved lipid metabolic regulator Dip2 family, results in progressive overgrowth of neurites in adults. We find that dip-2 mutants display specific genetic interactions with sax-2, the C. elegans ortholog of Drosophila Furry and mammalian FRY. Combined loss of DIP-2 and SAX-2 results in severe disruption of neuronal morphology maintenance accompanied by increased release of neuronal extracellular vesicles (EVs). By screening for suppressors of dip-2 sax-2 double mutant defects we identified gain-of-function (gf) mutations in the conserved Dopey family protein PAD-1 and its associated phospholipid flippase TAT-5/ATP9A. In dip-2 sax-2 double mutants carrying either pad-1(gf) or tat-5(gf) mutation, EV release is reduced and neuronal morphology across multiple neuron types is restored to largely normal. PAD-1(gf) acts cell autonomously in neurons. The domain containing pad-1(gf) is essential for PAD-1 function, and PAD-1(gf) protein displays increased association with the plasma membrane and inhibits EV release. Our findings uncover a novel functional network of DIP-2, SAX-2, PAD-1, and TAT-5 that maintains morphology of neurons and other types of cells, shedding light on the mechanistic basis of neurological disorders involving human orthologs of these genes.

Genetic patterns and genome-wide association analysis of eggshell quality traits of egg-type chicken across an extended laying period

The industry of egg-type chicken has shown a trend of extending the rearing period, with the goal of breeding chicken breeds capable of producing 500 qualified eggs by 700 d of age. However, the rapid decline in eggshell quality during the late laying period is one of the major challenges. In this study, a total of 3,261 Rhode Island Red chickens were used to measure eggshell quality traits including eggshell strength (ESS), eggshell thickness (EST), eggshell color (ESC) and eggshell gloss (ESG) at seven age points ranging from 36 to 90 wk of age. Phenotypic variations increased with the aging process, especially during the late laying period (> 55 wk), and the heritability during this period decreased by 22.7 to 81.4% compared to the initial and peak laying periods. Then we performed genome-wide association study (GWAS) to identify the genomic variants that associated with eggshell quality, with a custom Illumina 50K BeadChip, named PhenoixChip-I. The results indicated that 2 genomic regions on GGA1(23.24-25.15Mb; 175.95-176.05 Mb) were significantly (P < 4.48E-06) or suggestively (P < 8.97E-05) associated with ESS, which can explain 9.59% and 0.48% of the phenotypic variations of ESS46 and ESS36, respectively. Three genes, FRY, PCNX2, and ENSGALG00000052468, were considered to be the candidate genes for ESS. For other traits, the genome-wide suggestive SNPs were identified at each age point, exhibiting a certain trend with aging process. Additionally, SNP enrichment analysis and functional annotation of cross-tissue regulatory elements to ESS36 revealed a high concentration of enhancer elements specific to shell gland and kidney tissues. This study, deepened our knowledge of eggshells and laying a valued scientific foundation for chicken molecular breeding.

Hypoxia drives shared and distinct transcriptomic changes in two invasive glioma stem cell lines

Glioblastoma (GBM) is the most common primary malignant cancer of the central nervous system. Insufficient oxygenation (hypoxia) has been linked to GBM invasion and aggression, leading to poor patient outcomes. Hypoxia induces gene expression for cellular adaptations. However, GBM is characterized by high intertumoral (molecular subtypes) and intratumoral heterogeneity (cell states), and it is not well understood to what extent hypoxia triggers patient-specific gene responses and cellular diversity in GBM. Here, we surveyed eight patient-derived GBM stem cell lines for invasion phenotypes in 3D culture, which identified two GBM lines showing increased invasiveness in response to hypoxia. RNA-seq analysis of the two patient GBM lines revealed a set of shared hypoxia response genes concerning glucose metabolism, angiogenesis, and autophagy, but also a large set of patient-specific hypoxia-induced genes featuring cell migration and anti-inflammation, highlighting intertumoral diversity of hypoxia responses in GBM. We further applied the Shared GBM Hypoxia gene signature to single cell RNA-seq datasets of glioma patients, which showed that hypoxic cells displayed a shift towards mesenchymal-like (MES) and astrocyte-like (AC) states. Interestingly, in response to hypoxia, tumor cells in IDH-mutant gliomas displayed a strong shift to the AC state, whereas tumor cells in IDH-wildtype gliomas mainly shifted to the MES state. This distinct hypoxia response of IDH-mutant gliomas may contribute to its more favorable prognosis. Our transcriptomic studies provide a basis for future approaches to better understand the diversity of hypoxic niches in gliomas.

Inactivation of Hippo pathway characterizes a poor-prognosis subtype of esophageal cancer

Identification of molecular subtypes that reflect different prognoses and treatment responses, especially immune checkpoint inhibitors (ICIs) in esophageal squamous cell carcinoma (ESCC), is essential for treatment decisions. We performed targeted sequencing in 201 patients with ESCC to discover genetic subtypes and validate our findings via multiple data sets. We identified 3 driver genes (FCGBP, GRIN2B, and FRY), and recurrent truncating mutations in FRY impaired its tumor-suppressive function and promoted tumor proliferation. A 3-gene mutation signature (FAT1, FAT3, and FRY) recognized a molecular subtype named “FAT/FRY” with frequent Hippo pathway–related mutations. In multiple ESCC cohorts, the patients with the FAT/FRY subtype had poorer prognosis than did patients in the WT group. Transcriptome analysis indicated that the FAT/FRY subtype was characterized by inactivation of the Hippo pathway, hypoxia, chemoresistance, higher infiltration of CD8⁺ T cells and activated DCs, and a transcriptome similar to that of cancer responders. Furthermore, the 3-gene signature predicted better survival for patients treated with ICIs, partially explained by its positive correlation with the tumor mutation burden and neoantigen burden. The 3-gene signature is a biomarker to recognize the FAT/FRY molecular subtype, evaluate prognosis, and select potential beneficiaries of ICIs in ESCC.

Novel estrogen-responsive genes (ERGs) for the evaluation of estrogenic activity

Estrogen action is mediated by various genes, including estrogen-responsive genes (ERGs). ERGs have been used as reporter-genes and markers for gene expression. Gene expression profiling using a set of ERGs has been used to examine statistically reliable transcriptomic assays such as DNA microarray assays and RNA sequencing (RNA-seq). However, the quality of ERGs has not been extensively examined. Here, we obtained a set of 300 ERGs that were newly identified by six sets of RNA-seq data from estrogen-treated and control human breast cancer MCF-7 cells. The ERGs exhibited statistical stability, which was based on the coefficient of variation (CV) analysis, correlation analysis, and examination of the functional association with estrogen action using database searches. A set of the top 30 genes based on CV ranking were further evaluated quantitatively by RT-PCR and qualitatively by a functional analysis using the GO and KEGG databases and by a mechanistic analysis to classify ERα/β-dependent or ER-independent types of transcriptional regulation. The 30 ERGs were characterized according to (1) the enzymes, such as metabolic enzymes, proteases, and protein kinases, (2) the genes with specific cell functions, such as cell-signaling mediators, tumor-suppressors, and the roles in breast cancer, (3) the association with transcriptional regulation, and (4) estrogen-responsiveness. Therefore, the ERGs identified here represent various cell functions and cell signaling pathways, including estrogen signaling, and thus, may be useful to evaluate estrogenic activity.

The Hippo Signaling Pathway in Cancer: A Cell Cycle Perspective

Simple Summary

Cancer is increasingly viewed as a cell cycle disease in that the dysregulation of the cell cycle machinery is a common feature in cancer. The Hippo signaling pathway consists of a core kinase cascade as well as extended regulators, which together control organ size and tissue homeostasis. The aberrant expression of cell cycle regulators and/or Hippo pathway components contributes to cancer development, and for this reason, we specifically focus on delineating the roles of the Hippo pathway in the cell cycle. Improving our understanding of the Hippo pathway from a cell cycle perspective could be used as a powerful weapon in the cancer battlefield.

Abstract

Cell cycle progression is an elaborate process that requires stringent control for normal cellular function. Defects in cell cycle control, however, contribute to genomic instability and have become a characteristic phenomenon in cancers. Over the years, advancement in the understanding of disrupted cell cycle regulation in tumors has led to the development of powerful anti-cancer drugs. Therefore, an in-depth exploration of cell cycle dysregulation in cancers could provide therapeutic avenues for cancer treatment. The Hippo pathway is an evolutionarily conserved regulator network that controls organ size, and its dysregulation is implicated in various types of cancers. Although the role of the Hippo pathway in oncogenesis has been widely investigated, its role in cell cycle regulation has not been comprehensively scrutinized. Here, we specifically focus on delineating the involvement of the Hippo pathway in cell cycle regulation. To that end, we first compare the structural as well as functional conservation of the core Hippo pathway in yeasts, flies, and mammals. Then, we detail the multi-faceted aspects in which the core components of the mammalian Hippo pathway and their regulators affect the cell cycle, particularly with regard to the regulation of E2F activity, the G1 tetraploidy checkpoint, DNA synthesis, DNA damage checkpoint, centrosome dynamics, and mitosis. Finally, we briefly discuss how a collective understanding of cell cycle regulation and the Hippo pathway could be weaponized in combating cancer.

Synthetic molecules targeting yes associated protein activity as chemotherapeutics against cancer

The Hippo signaling pathway extorts several signals that concomitantly target the activity of transcriptional cofactor yes associated protein (YAP). YAP is a key regulator that elicits signature gene expression by coupling with transcriptional enhanced associate domain (TEAD) family of transcriptional factors. The YAP-TEAD complex via target gene expression gets associated with the development, proliferation, and progression of cancerous cells. Moreover, YAP adorns cells with several oncogenic traits such as inhibition of apoptosis, enhanced proliferation, drug resistance, and immune response suppression, which later became associated with various diseases, particularly cancer. Therefore, inhibition of the YAP activity is an appealing and viable therapeutic target for cancer treatment. This review highlights the recent advances in existing and novel synthetic therapeutics targeting YAP inhibition and regulation. The synthetically produced YAP^D93A belonging to cyclic peptides and DC-TEADin02 and vinyl sulfonamide class of compounds are the most potent compounds to inhibit the YAP-TEAD expression by targeting protein-protein interaction (IC₅₀  = 25 nM) and palmitate binding central pocket of TEAD (IC₅₀  = 197 nM), respectively. On the other hand, Chlorpromazine belonging to phenothiazines class has the least potential to suppress YAP via proteasomal degradation (cell viability value of <20% at 40 µM).

Furry is required for cell movements during gastrulation and functionally interacts with NDR1

Gastrulation is a key event in animal embryogenesis during which germ layer precursors are rearranged and the embryonic axes are established. Cell polarization is essential during gastrulation, driving asymmetric cell division, cell movements, and cell shape changes. The furry (fry) gene encodes an evolutionarily conserved protein with a wide variety of cellular functions, including cell polarization and morphogenesis in invertebrates. However, little is known about its function in vertebrate development. Here, we show that in Xenopus, Fry plays a role in morphogenetic processes during gastrulation, in addition to its previously described function in the regulation of dorsal mesoderm gene expression. Using morpholino knock-down, we demonstrate a distinct role for Fry in blastopore closure and dorsal axis elongation. Loss of Fry function drastically affects the movement and morphological polarization of cells during gastrulation and disrupts dorsal mesoderm convergent extension, responsible for head-to-tail elongation. Finally, we evaluate a functional interaction between Fry and NDR1 kinase, providing evidence of an evolutionarily conserved complex required for morphogenesis.

Targeting the Hippo Pathway in Prostate Cancer: What's New?

Simple Summary

Prostate cancer is the most commonly diagnosed cancer in men in the UK, accounting for the deaths of over 11,000 men per year. A major problem in this disease are tumours which no longer respond to available treatments. Understanding how this occurs will reveal new ways to treat these patients. In this review, the latest findings regarding a particular group of cellular factors which make up a signalling network called the Hippo pathway will be described. Accumulating evidence suggests that this network contributes to prostate cancer progression and resistance to current treatments. Identifying how this pathway can be targeted with drugs is a promising area of research to improve the treatment of prostate cancer.

Abstract

Identifying novel therapeutic targets for the treatment of prostate cancer (PC) remains a key area of research. With the emergence of resistance to androgen receptor (AR)-targeting therapies, other signalling pathways which crosstalk with AR signalling are important. Over recent years, evidence has accumulated for targeting the Hippo signalling pathway. Discovered in Drosophila melanogasta, the Hippo pathway plays a role in the regulation of organ size, proliferation, migration and invasion. In response to a variety of stimuli, including cell–cell contact, nutrients and stress, a kinase cascade is activated, which includes STK4/3 and LATS1/2 to inhibit the effector proteins YAP and its paralogue TAZ. Transcription by their partner transcription factors is inhibited by modulation of YAP/TAZ cellular localisation and protein turnover. Trnascriptional enhanced associate domain (TEAD) transcription factors are their classical transcriptional partner but other transcription factors, including the AR, have been shown to be modulated by YAP/TAZ. In PC, this pathway can be dysregulated by a number of mechanisms, making it attractive for therapeutic intervention. This review looks at each component of the pathway with a focus on findings from the last year and discusses what knowledge can be applied to the field of PC.

KIF4A enhanced cell proliferation and migration via Hippo signaling and predicted a poor prognosis in esophageal squamous cell carcinoma

Background

In this study, we aimed to explore and clarify the function of KIF4A in esophageal squamous cell carcinoma (ESCC).

Methods

The microarray data were extracted from the Gene Expression Omnibus (GEO) database. We then used the database for Annotation, Visualization, and Integrated Discovery (DAVID) to perform the gene ontology function (GO) and KEGG Orthology‐Based Annotation System (KOBAS) to perform Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of differentially expressed genes (DEGs). The six core candidate genes were identified using protein–protein interaction (PPI) network analysis and Cytoscape software. Among them, the expression of KIF4A were validated by UALCAN database from the Cancer Genome Atlas (TCGA) (P < 0.05). Western blotting, qRT‐PCR and IHC were used to detect the expression of KIF4A in tissues. Cell experiments (transwell migration assays, wound healing assay, CCK8 assay, and clone formation experiment) were utilized to verify the roles of KIF4A on the ESCC cells. Western blotting was used to explore the mechanism of KIF4A in ESCC.

Results

The expression level of KIF4A was upregulated in ESCC samples compared to those in paracancerous tissues. Transwell migration and wound healing assay showed overexpression of KIF4A significantly promoted the migration of ESCC cells. CCK8 assay and clone formation experiment analysis showed that overexpression of KIF4A promoted proliferation of ESCC cells. Western blot detection found that KIF4A could affect the phosphorylation level of Hippo signaling pathway related proteins.

Conclusions

In summary, KIF4A promotes ESCC cell proliferation and migration by regulating the biological function of ESCC cells through the Hippo signaling pathway.

Key points

Significant findings of the study

We found that high KIF4A expression was associated with poor overall survival in esophageal squamous cell carcinoma. KIF4A expression also promoted the proliferation and migration of ESCC cells in vitro.

What this study adds

Our experimental results explain the role of KIF4A in ESCC, and provide a new biomolecular target for the treatment of ESCC.