Search Results (19)

Vertebrate embryonic development relies on tightly regulated signaling pathways that guide morphogenesis, cell fate specification, and tissue organization. Among these, the Wnt signaling pathway plays a central role, orchestrating key developmental events. The non-canonical Wnt pathways, including the Planar Cell Polarity and Wnt/Ca²⁺ branches, are especially critical for regulating cytoskeletal dynamics during gastrulation. Recent studies highlight that these pathways interface with cytoskeletal effectors to control actin remodeling in response to extracellular cues. One such effector is Profilin, a small, evolutionarily conserved actin-binding protein that modulates actin polymerization and cellular architecture. Profilins, particularly Profilin1 and 2, are known to interact with Daam1, a formin protein downstream of PCP signaling, thereby linking Wnt signals to actin cytoskeletal regulation. Emerging evidence suggests that Profilins are active signaling intermediates that contribute to morphogenetic processes. Their context-dependent interactions and differential expression across species also suggest that they play specialized roles in development and disease. This review synthesizes the current understanding of Profilin’s role in non-canonical Wnt signaling, examining its molecular interactions and contributions to cytoskeletal control during development. By integrating data across model systems, we aim to clarify how Profilins function at the intersection of signaling and cytoskeletal dynamics, with implications for both developmental biology and disease pathogenesis. Full article

Ciliated epithelia are widespread in animals and play crucial roles in many developmental and physiological processes. Epithelia composed of multi-ciliated cells allow for directional fluid flow in the trachea, oviduct and brain cavities. Monociliated epithelia play crucial roles in vertebrate embryos, from the establishment of left–right asymmetry to the control of axis curvature via cerebrospinal flow motility in zebrafish. Cilia also have a central role in the motility and feeding of free-swimming larvae in a variety of marine organisms. These diverse functions rely on the coordinated orientation (rotational polarity) and asymmetric localization (translational polarity) of cilia and of their centriole-derived basal bodies across the epithelium, both being forms of planar cell polarity (PCP). Here, we review our current knowledge on the mechanisms of the translational polarity of basal bodies in vertebrate monociliated epithelia from the molecule to the whole organism. We highlight the importance of live imaging for understanding the dynamics of centriole polarization. We review the roles of core PCP pathways and of apicobasal polarity proteins, such as Par3, whose central function in this process has been recently uncovered. Finally, we emphasize the importance of the coordination between polarity proteins, the cytoskeleton and the basal body itself in this highly dynamic process. Full article

The planar cell polarity (PCP) of epithelial ciliated cells is essential for effective mucociliary clearance (MCC) in the sinonasal mucosa. We hypothesize that MCC coordination is impaired in nasal polyp (NP) mucosae due to the suppressed expression of a series of CPLANE (ciliogenesis and planar cell polarity effector) complex proteins in chronic rhinosinusitis (CRS) patients. To investigate this hypothesis, we subjected sinonasal mucosal samples to live video recording to measure mucociliary transport velocity (MCTV) and scanning electron microscopy to evaluate surface morphology. The expression and distribution of a panel of PCP proteins, e.g., WDPCP and FUZ, were investigated in relation to inflammatory cytokine levels and clinical features. The mean MCTV of NP mucosae was significantly lower than that of the inferior turbinate mucosae. The CRS group with NPs (CRSwNP group) (n = 28) showed increased expression of IL-13 and CCL26 mRNA compared to CRS patients without NPs (n = 25) and controls (n = 30). WDPCP and FUZ mRNA levels were significantly decreased in NP mucosae compared to ethmoid sinus mucosae in CRSwNP patients. WDPCP protein distribution was reduced in the cytoplasmic region of ciliated cells in CRSwNP patients. We conclude that suppression of WDPCP in ciliated cells is responsible for the impaired MCC of nasal polyps with type-2 inflammation. This mechanism might explain the decreased clearance and the potential for worsening symptoms of CRSwNP. Full article

The planar cell polarity (PCP) system is essential for positioning cells in 3D networks to establish the proper morphogenesis, structure, and function of organs during embryonic development. The PCP system uses inter- and intracellular feedback interactions between components of the core PCP, characterized by coordinated planar polarization and asymmetric distribution of cell populations inside the cells. PCP signaling connects the anterior–posterior to left–right embryonic plane polarity through the polarization of cilia in the Kupffer’s vesicle/node in vertebrates. Experimental investigations on various genetic ablation-based models demonstrated the functions of PCP in planar polarization and associated genetic disorders. This review paper aims to provide a comprehensive overview of PCP signaling history, core components of the PCP signaling pathway, molecular mechanisms underlying PCP signaling, interactions with other signaling pathways, and the role of PCP in organ and embryonic development. Moreover, we will delve into the negative feedback regulation of PCP to maintain polarity, human genetic disorders associated with PCP defects, as well as challenges associated with PCP. Full article

Planar cell polarity (PCP) proteins coordinate tissue morphogenesis by governing cell patterning and polarity. Asymmetrically localized on the plasma membrane of cells, transmembrane PCP proteins are trafficked by endocytosis, suggesting they may have intracellular functions that are dependent or independent of their extracellular role, but whether these functions extend to transcriptional control remains unknown. Here, we show the nuclear localization of transmembrane, PCP protein, VANGL2, in the HCC1569 breast cancer cell line, and in undifferentiated, but not differentiated, HC11 cells that serve as a model for mammary lactogenic differentiation. The loss of Vangl2 function results in upregulation of pathways related to STAT5 signaling. We identify DNA binding sites and a nuclear localization signal in VANGL2, and use CUT&RUN to demonstrate recruitment of VANGL2 to specific DNA binding motifs, including one in the Stat5a promoter. Knockdown (KD) of Vangl2 in HC11 cells and primary mammary organoids results in upregulation of Stat5a, Ccnd1 and Csn2, larger acini and organoids, and precocious differentiation; phenotypes are rescued by overexpression of Vangl2, but not Vangl2_ΔNLS. Together, these results advance a paradigm whereby PCP proteins coordinate tissue morphogenesis by keeping transcriptional programs governing differentiation in check. Full article

Wnt signaling has been shown to play multiple roles in regenerative processes, one of the most widely studied of which is the regeneration of the intestinal luminal epithelia. Most studies in this area have focused on self-renewal of the luminal stem cells; however, Wnt signaling may also have more dynamic functions, such as facilitating intestinal organogenesis. To explore this possibility, we employed the sea cucumber Holothuria glaberrima that can regenerate a full intestine over the course of 21 days after evisceration. We collected RNA-seq data from various intestinal tissues and regeneration stages and used these data to define the Wnt genes present in H. glaberrima and the differential gene expression (DGE) patterns during the regenerative process. Twelve Wnt genes were found, and their presence was confirmed in the draft genome of H. glaberrima. The expressions of additional Wnt-associated genes, such as Frizzled and Disheveled, as well as genes from the Wnt/β-catenin and Wnt/Planar Cell Polarity (PCP) pathways, were also analyzed. DGE showed unique distributions of Wnt in early- and late-stage intestinal regenerates, consistent with the Wnt/β-catenin pathway being upregulated during early-stages and the Wnt/PCP pathway being upregulated during late-stages. Our results demonstrate the diversity of Wnt signaling during intestinal regeneration, highlighting possible roles in adult organogenesis. Full article

Background: Treatment and outcomes of breast cancer, one of the most prevalent female cancers, have improved in recent decades. However, metastatic breast cancer remains incurable in most cases, and new therapies are needed to ameliorate prognosis. Planar cell polarity (PCP) is a characteristic of epithelial cells that form layers and is integral to the communication of these cells with neighboring cells. Dysfunction of PCP is observed in cancers and may confer a targetable vulnerability. Methods: The breast cancer cohorts from The Cancer Genome Atlas (TCGA) and the METABRIC study were interrogated for molecular alterations in genes of the PCP pathway. The groups with the most prevalent alterations were characterized, and survival was compared with counterparts not possessing PCP alterations. Breast cancer cell lines with PCP alterations from the Cancer Cell Line Encyclopedia (CCLE) were interrogated for sensitivity to drugs affecting PCP. Results: Among genes of the PCP pathway, VANGL2, NOS1AP and SCRIB display amplifications in a sizable minority of breast cancers. Concomitant up-regulation at the mRNA level can be observed mostly in basal cancers, but it does not correlate well with the amplification status of the genes, as it can also be observed in non-amplified cases. In an exploration of cell line models, two of the four breast cancer cell line models with amplifications in VANGL2, NOS1AP and SCRIB display sensitivity to drugs inhibiting acyl-transferase porcupine interfering with the WNT pathway. This sensitivity suggests a possible therapeutic role of these inhibitors in cancers bearing the amplifications. Conclusion: Molecular alterations in PCP genes can be observed in breast cancers with a predilection for the basal sub-type. An imperfect correlation of copy number alterations with mRNA expression suggests that post-translational modifications are important in PCP regulation. Inhibitors of acyl-transferase porcupine may be rational candidates for combination therapy development in PCP-altered breast cancers. Full article

Cannabigerol (CBG) is a non-psychoactive phytocannabinoid present in the Cannabis sativa L. plant. In our study, CBG at the concentration of 10 µM was used to treat NSC-34 motor neuron-like cells. The aim of the study was to evaluate the effects of CBG on NSC-34 cells, using next-generation sequencing (NGS) technology. Analysis showed the activation of the WNT/planar cell polarity (PCP) pathway and Ephrin-Eph signaling. The results revealed that CBG increases the expression of genes associated with the onset process of cytoskeletal remodeling and axon guidance. Full article

Primary cilia are non-motile organelles associated with the cell cycle, which can be found in most vertebrate cell types. Cilia formation occurs through a process called ciliogenesis, which involves several mechanisms including planar cell polarity (PCP) and the Hedgehog (Hh) signaling pathway. Some gene complexes, such as BBSome or CPLANE (ciliogenesis and planar polarity effector), have been linked to ciliogenesis. CPLANE complex is composed of INTU, FUZ and WDPCP, which bind to JBTS17 and RSG1 for cilia formation. Defects in these genes have been linked to a malfunction of intraflagellar transport and defects in the planar cell polarity, as well as defective activation of the Hedgehog signalling pathway. These faults lead to defective cilium formation, resulting in ciliopathies, including orofacial–digital syndrome (OFDS) and Bardet–Biedl syndrome (BBS). Considering the close relationship, between the CPLANE complex and cilium formation, it can be expected that defects in the genes that encode subunits of the CPLANE complex may be related to other ciliopathies. Full article

In vertebrates, the planar cell polarity (PCP) pathway regulates tissue morphogenesis during organogenesis, including the kidney. Mutations in human PCP effector proteins have been associated with severe syndromic ciliopathies. Importantly, renal hypoplasia has been reported in some patients. However, the developmental disturbance that causes renal hypoplasia is unknown. Here, we describe the early onset of profound renal hypoplasia in mice homozygous for null mutation of the PCP effector gene, Fuzzy. We found that this phenotype is caused by defective branching morphogenesis of the ureteric bud (UB) in the absence of defects in nephron progenitor specification or in early steps of nephrogenesis. By using various experimental approaches, we show that the loss of Fuzzy affects multiple signaling pathways. Specifically, we found mild involvement of GDNF/c-Ret pathway that drives UB branching. We noted the deficient expression of molecules belonging to the Bmp, Fgf and Shh pathways. Analysis of the primary cilia in the UB structures revealed a significant decrease in ciliary length. We conclude that renal hypoplasia in the mouse Fuzzy mutants is caused by defective UB branching associated with dysregulation of ciliary and non-ciliary signaling pathways. Our work suggests a PCP effector-dependent pathogenetic mechanism that contributes to renal hypoplasia in mice and humans. Full article

The differential activation of Wnt pathways (canonical: Wnt/β-catenin; non-canonical: planar cell polarity (PCP), Wnt/Ca²⁺) depends on the cell-specific availability and regulation of Wnt receptors, called Frizzled (FZD). FZDs selectively recruit co-receptors to activate various downstream effectors. We established a proximity ligation assay (PLA) for the detection of endogenous FZD–co-receptor interactions and analyzed time-dependent Wnt pathway activation in cultured cells. Prostate cancer cells (PC-3) stimulated by Wnt ligands (Wnt5A, Wnt10B) were analyzed by Cy3-PLA for the co-localization of FZD6 and co-receptors (canonical: LRP6, non-canonical: ROR1) at the single-cell level. Downstream effector activation was assayed by immunocytochemistry. PLA allowed the specific (siRNA-verified) detection of FZD6–LRP6 and FZD6–ROR1 complexes as highly fluorescent spots. Incubation with Wnt10B led to increased FZD6–LRP6 interactions after 2 to 4 min and resulted in nuclear accumulation of β-catenin within 5 min. Wnt5A stimulation resulted in a higher number of FZD6–ROR1 complexes after 2 min. Elevated levels of phosphorylated myosin phosphatase target 1 suggested subsequent Wnt/PCP activation in PC-3. This is the first study demonstrating time-dependent interactions of endogenous Wnt (co-)receptors followed by rapid Wnt/β-catenin and Wnt/PCP activation in PC-3. In conclusion, the PLA could uncover novel signatures of Wnt receptor activation in mammalian cells and may provide new insights into involved signaling routes. Full article

Emerging evidence has shown the oncogenic roles of leptin in modulating cancer progression in addition to its original roles. Analyses of transcriptomic data and patients’ clinical information have revealed leptin’s prognostic significance in renal cell carcinoma (RCC). However, its biological effects on RCC progression have not yet been explored. Clinical and transcriptomic data of a RCC cohort of 603 patients were retrieved from The Cancer Genome Atlas (TCGA) and analyzed to reveal the correlation of leptin with clinical outcomes and the hierarchical clustering of gene signatures based on leptin levels. In addition, cox univariate and multivariate regression analyses, cell migration upon leptin treatment, identification of putative leptin-regulated canonical pathways via ingenuity pathway analysis (IPA), and the investigation of induction of Wnt5a, ROR2, and Jun N-terminal Kinases (JNK) phosphorylation activation were performed. We first observed a correlation of high leptin levels and poor outcomes in RCC patients. Knowledge-based analysis by IPA indicated the induction of cancer cell migration by leptin, which was manifested via direct leptin treatment in the RCC cell lines. In RCC patients with high leptin levels, the planar cell polarity (PCP)/JNK signaling pathway was shown to be activated, and genes in the axis, including CTHRC1, FZD2, FZD10, ROR2, WNT2, WNT4, WNT10B, WNT5A, WNT5B, and WNT7B, were upregulated. All of these genes were associated with unfavorable clinical outcomes. WNT5A and ROR2 are pivotal upstream regulators of PCP/JNK signaling, and their correlations with leptin expression levels were displayed by a Pearson correlation analysis. The inhibition of signal transduction by SP600125 reversed leptin-mediated cell migration properties in RCC cell lines. The results indicate the prognostic impact of leptin on RCC patients and uncover its ability to promote cell migration via PCP/JNK signaling. Full article

MicroRNAs are frequently clustered in the genome and polycistronically transcribed, regulating targeted genes in diverse signaling pathways. The miR-17-92 cluster is a typical miRNA cluster, playing crucial roles in the organogenesis and homeostasis of physiological processes in vertebrates. Here, we identified three miRNAs (csa-miR-92a, csa-miR-92b, and csa-miR-92c) that belonged to the miR-92 family and formed a miRNA cluster in the genome of a urochordate marine ascidian Ciona savignyi. Except for miR-92a and miR-92b, other homologs of the vertebrate miR-17-92 cluster members could not be identified in the Ciona genome. We further found that the mature sequences of urochordate miR-92 family members were highly conserved compared with the vertebrate species. The expression pattern revealed that three miR-92 family members had consistent expression levels in adult tissues and were predominantly expressed in heart and muscle tissue. We further showed that, at the embryonic and larval stages, csa-miR-92c was expressed in the notochord of embryos during 18–31 h post fertilization (hpf) by in situ hybridization. Knockout of csa-miR-92c resulted in the disorganization of notochord cells and the block of lumen coalescence in the notochord. Fibroblast growth factor (FGF), mitogen-activated protein kinase (MAPK), and wingless/integrated (Wnt)/planar cell polarity (PCP) signaling pathways might be involved in the regulatory processes, since a large number of core genes of these pathways were the predicted target genes of the miR-92 family. Taken together, we identified a miR-92 cluster in urochordate Ciona and revealed the expression patterns and the regulatory roles of its members in organogenesis. Our results provide expression and phylogenetic data on the understanding of the miR-92 miRNA cluster’s function during evolution. Full article

The WNT pathway is one of the major signaling cascades frequently deregulated in human cancer. While research had initially focused on signal transduction centered on β-catenin as a key effector activating a pro-tumorigenic transcriptional response, nowadays it is known that WNT ligands can also induce a multitude of β-catenin-independent cellular pathways. Traditionally, these comprise WNT/planar cell polarity (PCP) and WNT/Ca²⁺ signaling. In addition, signaling via the receptor tyrosine kinase-like orphan receptors (RORs) has gained increasing attention in cancer research due to their overexpression in a multitude of tumor entities. Active WNT/ROR signaling has been linked to processes driving tumor development and progression, such as cell proliferation, survival, invasion, or therapy resistance. In adult tissue, the RORs are largely absent, which has spiked the interest in them for targeted cancer therapy. Promising results in preclinical and initial clinical studies are beginning to unravel the great potential of such treatment approaches. In this review, we summarize seminal findings on the structure and expression of the RORs in cancer, their downstream signaling, and its output in regard to tumor cell function. Furthermore, we present the current clinical anti-ROR treatment strategies and discuss the state-of-the-art, as well as the challenges of the different approaches. Full article

WNT-signaling controls important cellular processes throughout embryonic development and adult life, so any deregulation of this signaling can result in a wide range of pathologies, including cancer. WNT-signaling is classified into two categories: β-catenin-dependent signaling (canonical pathway) and β-catenin-independent signaling (non-canonical pathway), the latter can be further divided into WNT/planar cell polarity (PCP) and calcium pathways. WNT ligands are considered as unique directional growth factors that contribute to both cell proliferation and polarity. Origin of cancer can be diverse and therefore tissue-specific differences can be found in WNT-signaling between cancers, including specific mutations contributing to cancer development. This review focuses on the role of the WNT-signaling pathway in melanoma. The current view on the role of WNT-signaling in cancer immunity as well as a short summary of WNT pathway-related drugs under investigation are also provided. Full article