PCDH10 inhibits cell proliferation of multiple myeloma via the negative regulation of the Wnt/β-catenin/BCL-9 signaling pathway

Angelica sinensis polysaccharide suppresses the Wnt/β-catenin-mediated malignant biological behaviors of breast cancer cells via the miR-3187-3p/PCDH10 axis

Breast cancer (BC) is one of the most common malignant tumors in women. Angelica sinensis polysaccharide (ASP) is one of the main components extracted from the traditional Chinese medicine Angelica sinensis. Research has shown that ASP affects the progression of various cancers by regulating miRNA expression. This study aimed to explore the specific molecular mechanism by which ASP regulates BC progression through miR-3187-3p. After the overexpression or knockdown of miR-3187-3p and PDCH10 in BC cells, the proliferation, migration, invasion, and phenotype of BC cells were evaluated after ASP treatment. Bioinformatics software was used to predict the target genes of miR-3187-3p, and luciferase gene reporter experiments reconfirmed the targeted binding relationship. Subcutaneous tumor formation experiments were conducted in nude mice after the injection of BC cells. Western blot and Ki-67 immunostaining were performed on the tumor tissues. The results indicate that ASP can significantly inhibit the proliferation, migration, and invasion of BC cells. ASP can inhibit the expression of miR-3187-3p in BC cells and upregulate the expression of PDCH10 by inhibiting miR-3187-3p. A regulatory relationship exists between miR-3187-3p and PDCH10. ASP can inhibit the expression of β-catenin and phosphorylated glycogen synthase kinase-3β (p-GSK-3β) proteins through miR-3187-3p/PDCH10 and prevent the occurrence of malignant biological behavior in BC. Overall, this study revealed the potential mechanism by which ASP inhibits the BC process. ASP mediates the Wnt/β-catenin signaling pathway by affecting the miR-3187-3p/PDCH10 molecular axis, thereby inhibiting the proliferation, migration, invasion, and other malignant biological behaviors of BC cells.

Investigation of iso-propylchaetominine anticancer activity on apoptosis, cell cycle and Wnt signaling pathway in different cancer models

Dysregulation of the Wnt signaling pathway contributes to the development of many cancer types. Natural compounds produced with biotechnological systems have been the focus of research for being a new drug candidate both with unlimited resources and cost-effective production. In this study, it was aimed to reveal the effects of isopropylchaetominine on cytotoxic, cytostatic, apoptotic and Wnt signaling pathways in brain, pancreatic and prostate cancer. The IC50 values of isopropylchaetominine in U-87 MG, PANC1, PC3 and LNCaP cells were calculated as 91.94 μM, 41.68 μM, 54.54 μM and 7.86 μM in 72nd h, respectively. The metabolite arrests the cell cycle in G0/G1 phase in each cancer cells. Iso-propylchaetominine induced a 4.3-fold and 1.9-fold increase in apoptosis in PC3 and PANC1 cells, respectively. The toxicity of isopropylchaetominine in healthy fibroblast cells was assessed using the annexin V method, and no significant apoptotic activity was observed between the groups treated with the active substance and untreated. In U-87 MG, PANC1, PC3, and LNCaP cells under treatment with isopropylchaetominin, the expression levels of DKK3, TLE1, AES, DKK1, FRZB, DAB2, AXIN1/2, PPARD, SFRP4, APC and SOX17 tumor suppressor genes increased significantly. Decreases in expression of Wnt1, Wnt2, Wnt3, Wnt4, Wnt5, Wnt6, Wnt10, Wnt11, FRZ2, FRZ3, FRZ7, TCF7L1, BCL9, PYGO, CCND2, c-MYC, WISP1 and CTNNB1 oncogenic genes were detected. All these result shows that isopropylchaetominine can present promising new treatment strategy in different cancer types.

Impaired Angiogenic Function of Fetal Endothelial Progenitor Cells via PCDH10 in Gestational Diabetes Mellitus

Maternal hyperglycemia, induced by gestational diabetes mellitus (GDM), has detrimental effects on fetal vascular development, ultimately increasing the risk of cardiovascular diseases in offspring. The potential underlying mechanisms through which these complications occur are due to functional impairment and epigenetic changes in fetal endothelial progenitor cells (EPCs), which remain less defined. We confirm that intrauterine hyperglycemia leads to the impaired angiogenic function of fetal EPCs, as observed through functional assays of outgrowth endothelial cells (OECs) derived from fetal EPCs of GDM pregnancies (GDM-EPCs). Notably, PCDH10 expression is increased in OECs derived from GDM-EPCs, which is associated with the inhibition of angiogenic function in fetal EPCs. Additionally, increased PCDH10 expression is correlated with the hypomethylation of the PCDH10 promoter. Our findings demonstrate that in utero exposure to GDM can induce angiogenic dysfunction in fetal EPCs through altered gene expression and epigenetic changes, consequently increasing the susceptibility to cardiovascular diseases in the offspring of GDM mothers.

The role of Pcdh10 in neurological disease and cancer

BACKGROUND

Protocadherin 10 (PCDH 10), a member of the superfamily of protocadherins, is a Ca2+-dependent homophilic cell-cell adhesion molecule expressed on the surface of cell membranes. Protocadherin 10 plays a critical role in the central nervous system including in cell adhesion, formation and maintenance of neural circuits and synapses, regulation of actin assembly, cognitive function and tumor suppression. Additionally, Pcdh10 can serve as a non-invasive diagnostic and prognostic indicator for various cancers.

METHODS

This paper collects and reviews relevant literature in Pubmed.

CONCLUSION

This review describes the latest research understanding the role of Pcdh10 in neurological disease and human cancer, highlighting the importance of scrutinizing its properties for the development of targeted therapies and identifying a need for further research to explore Pcdh10 functions in other pathways, cell types and human pathologies.

E3 ubiquitin ligase RNF180 prevents excessive PCDH10 methylation to suppress the proliferation and metastasis of gastric cancer cells by promoting ubiquitination of DNMT1

BACKGROUND

Downregulation of certain tumor-suppressor genes (TSGs) by aberrant methylation of CpG islands in the promoter region contributes a great deal to the oncogenesis and progression of several cancers, including gastric cancer (GC). Protocadherin 10 (PCDH10) is a newly identified TSG in various cancers and is downregulated in GC; however, the specific mechanisms of PCDH10 in GC remain elusive. Here, we elucidated a novel epigenetic regulatory signaling pathway involving the E3 ubiquitin ligase RNF180 and DNA methyltransferase 1 (DNMT1), responsible for modulating PCDH10 expression by affecting its promoter methylation.

RESULTS

We revealed that PCDH10 was downregulated in GC cells and tissues, and low PCDH10 expression was correlated with lymph node metastasis and poor prognosis in patients with GC. Additionally, PCDH10 overexpression suppressed GC cell proliferation and metastasis. Mechanistically, DNMT1-mediated promoter hypermethylation resulted in decreased expression of PCDH10 in GC tissues and cells. Further analysis revealed that RNF180 can bind directly to DNMT1 and was involved in DNMT1 degradation via ubiquitination. Additionally, a positive correlation was found between RNF180 and PCDH10 expression and an inverse association between DNMT1 and PCDH10 expression showed considerable prognostic significance.

CONCLUSION

Our data showed that RNF180 overexpression upregulated PCDH10 expression via ubiquitin-dependent degradation of DNMT1, thus suppressing GC cell proliferation, indicating that the RNF180/DNMT1/PCDH10 axis could be a potential therapeutic target for GC treatment.

Genome-wide analysis toward the epigenetic aetiology of myelodysplastic syndrome disease progression and pharmacoepigenomic basis of hypomethylating agents drug treatment response

Myelodysplastic syndromes (MDS) consist of a group of hematological malignancies characterized by ineffective hematopoiesis, cytogenetic abnormalities, and often a high risk of transformation to acute myeloid leukemia (AML). So far, there have been only a very limited number of studies assessing the epigenetics component contributing to the pathophysiology of these disorders, but not a single study assessing this at a genome-wide level. Here, we implemented a generic high throughput epigenomics approach, using methylated DNA sequencing (MeD-seq) of LpnPI digested fragments to identify potential epigenomic targets associated with MDS subtypes. Our results highlighted that PCDHG and ZNF gene families harbor potential epigenomic targets, which have been shown to be differentially methylated in a variety of comparisons between different MDS subtypes. Specifically, CpG islands, transcription start sites and post-transcriptional start sites within ZNF124, ZNF497 and PCDHG family are differentially methylated with fold change above 3,5. Overall, these findings highlight important aspects of the epigenomic component of MDS syndromes pathogenesis and the pharmacoepigenomic basis to the hypomethylating agents drug treatment response, while this generic high throughput whole epigenome sequencing approach could be readily implemented to other genetic diseases with a strong epigenetic component.

Miz1 promotes KRAS-driven lung tumorigenesis by repressing the protocadherin Pcdh10

Targeting KRAS-mutated non-small-cell lung cancer (NSCLC) remains clinically challenging. Here we show that loss of function of Miz1 inhibits lung tumorigenesis in a mouse model of oncogenic KRAS-driven lung cancer. In vitro, knockout or silencing of Miz1 decreases cell proliferation, clonogenicity, migration, invasion, or anchorage-independent growth in mutant (MT) KRAS murine or human NSCLC cells but has unremarkable impact on non-tumorigenic cells or wild-type (WT) KRAS human NSCLC cells. RNA-sequencing reveals Protocadherin-10 (Pcdh10) as the top upregulated gene by Miz1 knockout in MT KRAS murine lung tumor cells. Chromatin immunoprecipitation shows Miz1 binding on the Pcdh10 promoter in MT KRAS lung tumor cells but not non-tumorigenic cells. Importantly, silencing of Pcdh10 rescues cell proliferation and clonogenicity in Miz1 knockout/knockdown MT KRAS murine or human tumor cells, and rescues allograft tumor growth of Miz1 knockout tumor cells in vivo. Miz1 is upregulated in MT KRAS lung tumor tissues compared with adjacent non-involved tissues in mice. Consistent with this, Miz1 is upregulated while Pcdh10 is downregulated in human lung adenocarcinomas (LUAD) compared with normal tissues, and high Miz1 levels or low Pcdh10 levels are associated with poor survival in lung cancer patients. Furthermore, the Miz1 signature is associated with worse survival in MT but not WT KRAS LUAD, and Pcdh10 is downregulated in MT compared to WT KRAS LUAD. Taken together, our studies implicate the Miz1/Pcdh10 axis in oncogenic KRAS-driven lung tumorigenesis.

Protocadherin gamma C3: a new player in regulating vascular barrier function

Defects in the endothelial cell barrier accompany diverse malfunctions of the central nervous system such as neurodegenerative diseases, stroke, traumatic brain injury, and systemic diseases such as sepsis, viral and bacterial infections, and cancer. Compromised endothelial sealing leads to leaking blood vessels, followed by vasogenic edema. Brain edema as the most common complication caused by stroke and traumatic brain injury is the leading cause of death. Brain microvascular endothelial cells, together with astrocytes, pericytes, microglia, and neurons form a selective barrier, the so-called blood-brain barrier, which regulates the movement of molecules inside and outside of the brain. Mechanisms that regulate blood-brain barrier permeability in health and disease are complex and not fully understood. Several newly discovered molecules that are involved in the regulation of cellular processes in brain microvascular endothelial cells have been described in the literature in recent years. One of these molecules that are highly expressed in brain microvascular endothelial cells is protocadherin gamma C3. In this review, we discuss recent evidence that protocadherin gamma C3 is a newly identified key player involved in the regulation of vascular barrier function.

The Wnt/β-catenin signalling pathway in Haematological Neoplasms

Leukaemia and lymphoma are common malignancies. The Wnt pathway is a complex network of proteins regulating cell proliferation and differentiation, as well as cancer development, and is divided into the Wnt/β-catenin signalling pathway (the canonical Wnt signalling pathway) and the noncanonical Wnt signalling pathway. The Wnt/β-catenin signalling pathway is highly conserved evolutionarily, and activation or inhibition of either of the pathways may lead to cancer development and progression. The aim of this review is to analyse the mechanisms of action of related molecules in the Wnt/β-catenin pathway in haematologic malignancies and their feasibility as therapeutic targets.

Protocadherin 15 suppresses oligodendrocyte progenitor cell proliferation and promotes motility through distinct signalling pathways

Oligodendrocyte progenitor cells (OPCs) express protocadherin 15 (Pcdh15), a member of the cadherin superfamily of transmembrane proteins. Little is known about the function of Pcdh15 in the central nervous system (CNS), however, Pcdh15 expression can predict glioma aggression and promote the separation of embryonic human OPCs immediately following a cell division. Herein, we show that Pcdh15 knockdown significantly increases extracellular signal-related kinase (ERK) phosphorylation and activation to enhance OPC proliferation in vitro. Furthermore, Pcdh15 knockdown elevates Cdc42-Arp2/3 signalling and impairs actin kinetics, reducing the frequency of lamellipodial extrusion and slowing filopodial withdrawal. Pcdh15 knockdown also reduces the number of processes supported by each OPC and new process generation. Our data indicate that Pcdh15 is a critical regulator of OPC proliferation and process motility, behaviours that characterise the function of these cells in the healthy CNS, and provide mechanistic insight into the role that Pcdh15 might play in glioma progression.

Protocadherin 15 promotes lamellipodial and filopodial dynamics in oligodendrocyte progenitor cells by regulating Cdc42-Arp2/3 activity, but also suppresses ERK1/2 phosphorylation to reduce proliferation.

Innovative mouse models for the tumor suppressor activity of Protocadherin-10 isoforms

Background

Nonclustered mouse protocadherin genes (Pcdh) encode proteins with a typical single ectodomain and a cytoplasmic domain with conserved motifs completely different from those of classic cadherins. Alternative splice isoforms differ in the size of these cytoplasmic domains. In view of the compelling evidence for gene silencing of protocadherins in human tumors, we started investigations on Pcdh functions in mouse cancer models.

Methods

For Pcdh10, we generated two mouse lines: one with floxed exon 1, leading to complete Pcdh10 ablation upon Cre action, and one with floxed exons 2 and 3, leading to ablation of only the long isoforms of Pcdh10. In a mouse medulloblastoma model, we used GFAP-Cre action to locally ablate Pcdh10 in combination with Trp53 and Rb1 ablation. From auricular tumors, that also arose, we obtained tumor-derived cell lines, which were analyzed for malignancy in vitro and in vivo. By lentiviral transduction, we re-expressed Pcdh10 cDNAs. RNA-Seq analyses were performed on these cell families.

Results

Surprisingly, not only medulloblastomas were generated in our model but also tumors of tagged auricles (pinnae). For both tumor types, ablation of either all or only long isoforms of Pcdh10 aggravated the disease. We argued that the perichondrial stem cell compartment is at the origin of the pinnal tumors. Immunohistochemical analysis of these tumors revealed different subtypes. We obtained several pinnal-tumor derived (PTD) cell lines and analyzed these for anchorage-independent growth, invasion into collagen matrices, tumorigenicity in athymic mice. Re-expression of either the short or a long isoform of Pcdh10 in two PTD lines counteracted malignancy in all assays. RNA-Seq analyses of these two PTD lines and their respective Pcdh10-rescued cell lines allowed to identify many interesting differentially expressed genes, which were largely different in the two cell families.

Conclusions

A new mouse model was generated allowing for the first time to examine the remarkable tumor suppression activity of protocadherin-10 in vivo. Despite lacking several conserved motifs, the short isoform of Pcdh10 was fully active as tumor suppressor. Our model contributes to scrutinizing the complex molecular mechanisms of tumor initiation and progression upon PCDH10 silencing in many human cancers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09381-y.

Hsa_circ_0001666 suppresses the progression of colorectal cancer through the miR-576-5p/PCDH10 axis

BACKGROUND

Though circular RNAs, new non-coding RNA classes have demonstrated that they have an essential role in the initiation as well as development of CRC (colorectal cancer), whereas in CRC the function and mechanism of hsa_circ_0001666 are less known.

METHODS

Hsa_circ_0001666 was identified by bioinformatics analysis of a circRNA microarray from the GEO database, and its expression in both CRC cell lines and tissues was analysed. A series of in vitro along with in vivo experiments were carried out for exploring the hsa_circ_0001666 functions, including transwell, wound healing, flow cytometry, colony formation, Edu, CCK-8, soft agar colony formation, tumor xenografts and lung/liver metastasis in mice. RNA pull-down, RIP (RNA immunoprecipitation), luciferase reporter assay, FISH (fluorescence in situ hybridization) and rescue experiments were used for determining the correlation among hsa_circ_0001666, miR-576-5p and PCDH10.

RESULTS

Hsa_circ_0001666 was downregulated in both CRC cell lines along with tumour tissues. A higher expression level of hsa_circ_0001666 indicated a better clinical prognosis in patients with CRC. Hsa_circ_0001666 knockdown significantly supported CRC cell proliferation along with invasion and inhibited cell apoptosis in vitro. Hsa_circ_0001666 knockdown accelerated the CRC growth and metastasis in vivo. Moreover, the mechanistic study showed that hsa_circ_0001666, acting as 'ceRNA' of miR-576-5p, prevented PCDH10 downregulation, as well as suppressed EMT and stemness of CRC cells, and the Wnt/β-catenin signalling pathway. Inhibiting miR-576-5p or overexpressing PCDH10 could reverse phenotypic changes caused by knocking down of hsa_circ_0001666.

CONCLUSIONS

Hsa_circ_0001666 suppresses CRC progression through the miR-576-5p/PCDH10 axis and may provide a new insight for the diagnosis and treatment of CRC.

δ-Protocadherins regulate neural progenitor cell division by antagonizing Ryk and Wnt/β-catenin signaling

The division of neural progenitor cells provides the cellular substrate from which the nervous system is sculpted during development. The δ-protocadherin family of homophilic cell adhesion molecules is essential for the development of the vertebrate nervous system and is implicated in an array of neurodevelopmental disorders. We show that lesions in any of six, individual δ-protocadherins increases cell divisions of neural progenitors in the hindbrain. This increase is due to mis-regulation of Wnt/β-catenin signaling, as this pathway is upregulated in δ-protocadherin mutants and inhibition of this pathway blocks the increase in cell division. Furthermore, the δ-protocadherins can be present in complex with the Wnt receptor Ryk, and Ryk is required for the increased proliferation in protocadherin mutants. Thus, δ-protocadherins are novel regulators of Wnt/β-catenin signaling that may control the development of neural circuits by defining a molecular code for the identity of neural progenitor cells and differentially regulating their proliferation.

Identification and Characterization of Multiple Myeloma Stem Cell-Like Cells

Multiple myeloma (MM) is a B-cell tumor of the blood system with high incidence and poor prognosis. With a further understanding of the pathogenesis of MM and the bone marrow microenvironment, a variety of adjuvant cell therapies and new drugs have been developed. However, the drug resistance and high relapse rate of MM have not been fundamentally resolved. Studies have shown that, in patients with MM, there is a type of poorly differentiated progenitor cell (MM stem cell-like cells, MMSCs). Although there is no recognized standard for identification and classification, it is confirmed that they are closely related to the drug resistance and relapse of MM. This article therefore systematically summarizes the latest developments in MMSCs with possible markers of MMSCs, introduces the mechanism of how MMSCs work in MM resistance and recurrence, and discusses the active pathways that related to stemness of MM.

A review of the current state of knowledge on sex differences in sleep and circadian phenotypes in rodents

Sleep is a vital part of our lives as it is required to maintain health and optimal cognition. In humans, sex differences are relatively well-established for many sleep phenotypes. However, precise differences in sleep phenotypes between male and female rodents are less documented. The main goal of this article is to review sex differences in sleep architecture and electroencephalographic (EEG) activity during wakefulness and sleep in rodents. The effects of acute sleep deprivation on sleep duration and EEG activity in male and female rodents will also be covered, in addition to sex differences in specific circadian phenotypes. When possible, the contribution of the female estrous cycle to the observed differences between males and females will be described. In general, male rodents spend more time in non-rapid eye movement sleep (NREMS) in comparison to females, while other differences between sexes in sleep phenotypes are species- and estrous cycle phase-dependent. Altogether, the review illustrates the need for a sex-based perspective in basic sleep and circadian research, including the consideration of sex chromosomes and gonadal hormones in sleep and circadian phenotypes.

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In rodents, males spend less time awake, and more time in NREMS than females.

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The recovery from sleep deprivation is also dependent on biological sex.

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Gonadal hormones modulate sleep and circadian phenotypes in rodents.

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A more systematic comparison of sex in basic sleep/circadian research is needed.

Comprehensive CRISPR-Cas9 screens identify genetic determinants of drug responsiveness in multiple myeloma

The introduction of new drugs in the past years has substantially improved outcome in multiple myeloma (MM). However, the majority of patients eventually relapse and become resistant to one or multiple drugs. While the genetic landscape of relapsed/ resistant multiple myeloma has been elucidated, the causal relationship between relapse-specific gene mutations and the sensitivity to a given drug in MM has not systematically been evaluated. To determine the functional impact of gene mutations, we performed combined whole-exome sequencing (WES) of longitudinal patient samples with CRISPR-Cas9 drug resistance screens for lenalidomide, bortezomib, dexamethasone, and melphalan. WES of longitudinal samples from 16 MM patients identified a large number of mutations in each patient that were newly acquired or evolved from a small subclone (median 9, range 1-55), including recurrent mutations in TP53, DNAH5, and WSCD2. Focused CRISPR-Cas9 resistance screens against 170 relapse-specific mutations functionally linked 15 of them to drug resistance. These included cereblon E3 ligase complex members for lenalidomide, structural genes PCDHA5 and ANKMY2 for dexamethasone, RB1 and CDK2NC for bortezomib, and TP53 for melphalan. In contrast, inactivation of genes involved in the DNA damage repair pathway, including ATM, FANCA, RAD54B, and BRCC3, enhanced susceptibility to cytotoxic chemotherapy. Resistance patterns were highly drug specific with low overlap and highly correlated with the treatment-dependent clonal evolution in patients. The functional association of specific genetic alterations with drug sensitivity will help to personalize treatment of MM in the future.

The influence of circular RNAs on autophagy and disease progression

Circular RNAs (circRNAs) are non-coding RNAs that have attracted considerable attention in recent years. Owing to their distinct circular structure, circRNAs are stable in cells. Autophagy is a catabolic process that helps in the degradation and recycling of harmful or inessential biological macromolecules in cells and enables cells to adapt to stress and changes in the internal and external environments. Evidence has shown that circRNAs influence the course of a disease by regulating autophagy, which indicates that autophagy is involved in the onset and development of various diseases and can affect drug resistance (for example, it affects cisplatin resistance in tumors). In this review, we summarized the role of circRNAs in autophagy and their influence on disease onset and progression as well as drug resistance. The review will expand our understanding of tumors as well as cardiovascular and neurological diseases and also suggest novel therapeutic strategies.Abbreviations: ACR: autophagy-related circRNA; ADSCs: adipogenic mesenchymal stem cells; AMPK: AMP-activated protein kinase; ATG: autophagy related; BCL2: BCL2 apoptosis regulator; BECN1: beclin 1; ceRNA: competing endogenous RNA; circRNA: circular RNA; CMA: chaperone-mediated autophagy; EPCs: endothelial progenitor cells; LE/MVBs: late endosomes/multivesicular bodies; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; NSCLC: non-small cell lung cancer; PDLSCs: periodontal ligament stem cells; PE: phosphatidylethanolamine; PtdIns: phosphatidylinositol; PtdIns3K: phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate 1,2-dipalmitoyl; PTEN: phosphatase and tensin homolog; RBPs: RNA-binding proteins; SiO₂: silicon dioxide; TFEB: transcription factor EB; ULK: unc-51 like autophagy activating kinase 1.

BCL9/BCL9L promotes tumorigenicity through immune-dependent and independent mechanisms in triple negative breast cancer

Treatment of patients with triple-negative breast cancer (TNBC) has been challenging due to a lack of well-defined molecular targets. The Wnt/β-catenin pathway is known to be activated in many TNBC patients and BCL9 and BCL9L are important transcriptional co-activators of β-catenin, but whether inhibition of BCL9/BCL9L can suppress TNBC growth and the underlying mechanism are not fully understood. Here we demonstrate that the expression of BCL9 and BCL9L is directly correlated with malignancy in TNBC patient tumors and that BCL9 and BCL9L promote tumor cell growth, cell migration and metastasis in TNBC models. Mechanistically, we found that BCL9/BCL9L promotes tumorigenicity through both the Wnt and TGF-β pathways. Besides, BCL9/BCL9L expression inversely correlates with CD8⁺ T cell infiltration in TNBC and BCL9/BCL9L inhibits the infiltration of CD8⁺ T cells in the tumor microenvironment. hsBCL9_CT-24, an inhibitor of BCL9/β-catenin peptides, promotes intratumoral infiltration of cytotoxic T cells, reducing regulatory T cells (Treg) and increasing dendritic cells (DCs). Inhibition of BCL9/BCL9L and TGF-β suppresses activity of Treg. TGF-β signaling increases tumor infiltration of cytotoxic CD8⁺ T cells. In accordance, genetic or pharmacological inhibition of BCL9/BCL9L synergizes with PD-1/L1 antibodies to inhibit tumor growth. In summary, these results suggest that targeting BCL9/BCL9L has a direct anti-tumor effect and also unleashes an anti-cancer immune response through inhibition of both Wnt and TGF-β signaling, suggesting a viable therapeutic approach for TNBC treatment.

Identifying Signatures of Selection Related to Comb Development

The aim of this study was to identify genes involved in comb development to provide insights into the molecular mechanism of chickens' comb formation. Fixation index (FST) and average number of base differences (π) of males with large and small combs were calculated based on whole-genome resequencing data. Chromosome regions with larger FST values and smaller π were considered candidate selection regions. Through further annotation of gene functions and pathways, we sought to screen possible selected genes associated with comb development. By screening whole genome resequencing data, FST and π were calculated using a 40 Kb sliding window strategy and eight regions were identified. Quantitative trait loci (QTL; FOX1 gene) related to comb length were found on chromosome 1. QTL (GLP1R, BTBD9, MIR6633, and MDGA1 genes) related to comb weight were found on chromosome 3. QTL (ALDH1A1, TMC1, and ANXA1 genes) associated with comb area were found on the Z chromosome. Nineteen genes, Wnt signaling pathway and neuroactive ligand-receptor interaction signaling pathway directly or indirectly related to comb growth and development were found through functional annotation and GO analysis. Among the selected genes LYN, GLP1R, FOX1, TBK1, STRAP, ST6GALNAC, and Wnt signaling pathways were related to immunity. MDGA1, BTBD9, MTSS1, SrGAPs, and neuroactive ligand receptor interaction signaling pathways related to neural function were screened. ALDH1A1, ANXAl, THBS, HIF-1α, and ACTN1 genes were related to heat dissipation. Among the selected genes FOX1, MDGAl, and ANXAl associated with immunity, neurological function, and heat dissipation function coincided with genes affecting the length, weight, and area of the comb. Comprehensive analysis suggested that comb development was due to multiple genes and signaling pathways.

PCDH10 exerts tumor-suppressor functions through modulation of EGFR/AKT axis in colorectal cancer

Protocadherin 10 (PCDH10) is identified as a tumor suppressor in multiple cancers. The molecular mechanisms that mediate the functions of PCDH10 have yet to be fully elucidated. Here, we demonstrated that ectopic expression of PCDH10 in colorectal cancer (CRC) cells induced cell cycle retardation and increased apoptosis through regulation of the p53/p21/Rb axis and Bcl-2 expression. Overexpression of PCDH10 reversed the epithelial-mesenchymal transition (EMT) process with morphological changes and EMT marker alterations. Mechanistic study revealed that PCDH10 inhibited AKT/GSK3β signaling pathway which in turn reduced β-catenin activity and thus attenuated Snail and Twist1 expression. Furthermore, PCDH10 inhibited the stemness of CRC cells, including spheroid formation and stem cell markers. A proteomics approach revealed that PCDH10 could interact with EGFR, which was further verified by co-immunoprecipitation. Moreover, restoration of PCDH10 expression reduced EGFR phosphorylation. Accordingly, our work proposes a novel pathway by which PCDH10 directly engages in the negative regulation of EGFR/AKT/β-catenin signaling pathway, resulting in tumor suppression.

Overexpression of gene DEP domain containing 1 and its clinical prognostic significance in colorectal cancer

Background

Colorectal cancer (CRC) is one of the most commonly seen malignancies worldwide, yet its regulatory mechanisms still need to be further illuminated. Abundant evidence revealed that aberrant expression of cancer‐related genes contributes to CRC progression. DEP domain containing 1 (DEPDC1) has been found to play a crucial role in the carcinogenesis and development of malignancies. Nevertheless, limited studies have been concerned with the role of DEPDC1 in CRC. This study aimed to investigate the relationship between DEPDC1 expression and CRC clinicopathological parameters.

Methods

Solid CRC tissues and adjacent noncancerous tissues (ANCTs) (n = 150) were chosen randomly to detect the mRNA expression levels of DEPDC1 by real‐time quantitative reverse transcription‐polymerase chain reaction (RT‐qPCR). Formalin‐fixed, paraffin‐embedded (FFPE) blocks of CRC tissues and ANCTs (n = 150) were acquired to examine DEPDC1 protein expression levels by immunohistochemistry (IHC).

Results

DEPDC1 was significantly overexpressed in CRC tissues than that in ANCTs (P < .05). High protein expression of DEPDC1 was associated with poorer TNM stage and recurrence (P < .001 and P = .003, respectively). Kaplan‐Meier survival analysis showed significantly shorter overall survival (OS) and disease‐free survival (DFS) in DEPDC1 protein high‐expression group compared with low‐expression group (P < .05). Univariate analysis demonstrated that DEPDC1 protein expression was correlated with DFS (P = .005) and OS (P = .006). Multivariate analysis revealed that the combination of DEPDC1 protein expression and TNM stage has statistical significance in CRC prognosis prediction (P = .024 and P = .009, respectively).

Conclusions

DEPDC1 may act as a potential biomarker for CRC detection as well as a prognostic predictor concerning the survival of CRC patients.

Proximity-dependent Proteomics Reveals Extensive Interactions of Protocadherin-19 with Regulators of Rho GTPases and the Microtubule Cytoskeleton

Protocadherin-19 belongs to the cadherin family of cell surface receptors and has been shown to play essential roles in the development of the vertebrate nervous system. Mutations in human Protocadherin-19 (PCDH19) lead to PCDH19 Female-limited epilepsy (PCDH19 FLE) in humans, characterized by the early onset of epileptic seizures in children and a range of cognitive and behavioral problems in adults. Despite being considered the second most prevalent gene in epilepsy, very little is known about the intercellular pathways in which it participates. In order to characterize the protein complexes within which Pcdh19 functions, we generated Pcdh19-BioID fusion proteins and utilized proximity-dependent biotinylation to identify neighboring proteins. Proteomic identification and analysis revealed that the Pcdh19 interactome is enriched in proteins that regulate Rho family GTPases, microtubule binding proteins and proteins that regulate cell divisions. We cloned the centrosomal protein Nedd1 and the RacGEF Dock7 and verified their interactions with Pcdh19 in vitro. Our findings provide the first comprehensive insights into the interactome of Pcdh19, and provide a platform for future investigations into the cellular and molecular biology of this protein critical to the proper development of the nervous system.

Effect of bortezomib on proliferation and apoptosis of myeloma cells by activating Wnt/β-catenin signaling pathway

Effect of bortezomib on proliferation and apoptosis of myeloma cells by activating Wnt/β-catenin signaling pathway was investigated. Myeloma cells RPMI-8226 treated with different concentrations of bortezomib were used as experimental groups, and the untreated cells were used as the control group. The proliferation and apoptosis in all groups of cells were detected, as well as the expression levels of Wnt/β-catenin signaling pathway-related proteins, β-catenin and c-Myc. The results revealed that bortezomib could inhibit the proliferation of myeloma cells. The apoptotic rates of RPMI-8226 cells in the groups treated with 20, 50 and 80 nmol/l of bortezomib were 12.08±0.61, 35.97±3.11 and 57.22±5.47%, respectively, which were significantly higher than that in the control group (8.28±0.39%) (P<0.05). The expression levels of β-catenin and c-Myc in the experimental groups were significantly lower than those in the control group (P<0.05). Bortezomib can reduce the expression level of Wnt/β-catenin signaling pathway-related proteins, β-catenin and c-Myc, and may inhibit cell proliferation and accelerate apoptosis by activating the Wnt/β-catenin signaling pathway.

Protocadherins at the Crossroad of Signaling Pathways

Protocadherins (Pcdhs) are cell adhesion molecules that belong to the cadherin superfamily, and are subdivided into clustered (cPcdhs) and non-clustered Pcdhs (ncPcdhs) in vertebrates. In this review, we summarize their discovery, expression mechanisms, and roles in neuronal development and cancer, thereby highlighting the context-dependent nature of their actions. We furthermore provide an extensive overview of current structural knowledge, and its implications concerning extracellular interactions between cPcdhs, ncPcdhs, and classical cadherins. Next, we survey the known molecular action mechanisms of Pcdhs, emphasizing the regulatory functions of proteolytic processing and domain shedding. In addition, we outline the importance of Pcdh intracellular domains in the regulation of downstream signaling cascades, and we describe putative Pcdh interactions with intracellular molecules including components of the WAVE complex, the Wnt pathway, and apoptotic cascades. Our overview combines molecular interaction data from different contexts, such as neural development and cancer. This comprehensive approach reveals potential common Pcdh signaling hubs, and points out future directions for research. Functional studies of such key factors within the context of neural development might yield innovative insights into the molecular etiology of Pcdh-related neurodevelopmental disorders.

A Membranome-Centered Approach Defines Novel Biomarkers for Cellular Subtypes in the Intervertebral Disc

OBJECTIVE

Lack of specific marker-sets prohibits definition and functional distinction of cellular subtypes in the intervertebral disc (IVD), such as those from the annulus fibrosus (AF) and the nucleus pulposus (NP).

DESIGN

We recently generated immortalized cell lines from human NP and AF tissues; these comprise a set of functionally distinct clonal subtypes. Whole transcriptome analyses were performed of 12 phenotypically distinct clonal cell lines (4× NP-Responder, 4× NP-nonResponder, 2× AF-Sheet forming, and 2× AF-nonSheet forming). Data sets were filtered for membrane-associated marker genes and compared to literature.

RESULTS

Comparison of our immortal cell lines to published primary NP, AF, and articular chondrocytes (AC) transcriptome datasets revealed preservation of AF and NP phenotypes. NP-specific membrane-associated genes were defined by comparison to AF cells in both the primary dataset (46 genes) and immortal cell-lines (161 genes). Definition of AF-specific membrane-associated genes yielded 125 primary AF cell and 92 immortal cell-line markers. Overlap between primary and immortal NP cells yielded high-confidence NP-specific marker genes for NP-R (CLDN11, TMEFF2, CA12, ANXA2, CD44) and NP-nR (EFNA1, NETO2, SLC2A1). Overlap between AF and immortal AF subtypes yielded specific markers for AF-S (COLEC12, LPAR1) and AF-nS (CHIC1).

CONCLUSIONS

The current study provides a reference platform for preclinical evaluation of novel membrane-associated cell type-specific markers in the IVD. Future research will focus on their biological relevance for IVD function in development, homeostasis, and degenerate conditions.

PCDH20 acts as a tumour-suppressor gene through the Wnt/β-catenin signalling pathway in hypopharyngeal squamous cell carcinoma

BACKGROUND

Downregulation of PCDH20 is frequently involved in tumorigenesis of many cancers, but the role of PCDH20 protein in hypopharyngeal squamous cell carcinoma (HSCC) is still unknown.

OBJECTIVE

The aim of this study was to investigate the role of PCDH20 in hypopharyngeal squamous cell carcinoma (HSCC).

METHODS

Immunohistochemistry (IHC) and qRT-PCR was carried out to estimate the expressions of PCDH20 protein and mRNA in HSCC tissues and adjacent non-tumor tissues. Correlation between the PCDH20 expression and clinicopathological characteristics was evaluated using chi-square test. Meanwhile, Kaplan-Meier method and log-rank test were applied to analyze the overall survival. After transfection of PCDH20, the CCK8 assay, Cell migration assay and invasion assay were used to investigate the changes in the viability, migration and invasion of Fuda cells. The mechanisms by which reduced PCDH20 promote migration and invasion of Fuda cells were examined using western blotting.

RESULTS

PCDH20 protein showed in tumor tissue low expression rates of 67.5% (54/80). The mRNA of PCDH20 indicated the consistent trend (80%, 8/10). Reduced PCDH20 expression was positively related to T stage and lymph node metastasis (P< 0.05). Patients with low levels of PCDH20 had worse overall survival compared with those with high PCDH20 levels (P< 0.001). The univariate Cox regression analysis described that lymph node metastasis (P= 0.043) and down-regulated PCDH20 expression (P= 0.045) were significantly prognostic factors.Multivariate analysis suggested that low PCDH20 expression (P= 0.015) were significantly independent prognostic factors for overall survival. PCDH20 in Fadu cells significantly inhibited cell viability, migration and invasion. Meanwhile, PCDH20 was involved in the disruption of HSCC progression through antagonizing its downstream Wnt/β-catenin signalling pathway.

CONCLUSION

Our data highlight that the downregulated PCDH20 may serve as reliable diagnostic biomarker in HSCC.

Cadherin Signaling in Cancer: Its Functions and Role as a Therapeutic Target

Cadherin family includes lists of transmembrane glycoproteins which mediate calcium-dependent cell-cell adhesion. Cadherin-mediated adhesion regulates cell growth and differentiation throughout life. Through the establishment of the cadherin-catenin complex, cadherins provide normal cell-cell adhesion and maintain homeostatic tissue architecture. In the process of cell recognition and adhesion, cadherins act as vital participators. As results, the disruption of cadherin signaling has significant implications on tumor formation and progression. Altered cadherin expression plays a vital role in tumorigenesis, tumor progression, angiogenesis, and tumor immune response. Based on ongoing research into the role of cadherin signaling in malignant tumors, cadherins are now being considered as potential targets for cancer therapies. This review will demonstrate the mechanisms of cadherin involvement in tumor progression, and consider the clinical significance of cadherins as therapeutic targets.

Matrine induces apoptosis and autophagy of glioma cell line U251 by regulation of circRNA-104075/BCL-9

BACKGROUND

Matrine, a traditional Chinese medicine, has been reported to exert anti-tumor effects in several types of cancers. Here, we explored the anti-tumor effects of matrine on the glioma cells.

METHODS

Glioma cell line U251 cells were treated with matrine to assess viability and proliferation using CCK8 and EdU assays. PI/FITC staining was performed for apoptosis assay. Transfections were performed for circRNA-104075 or Bcl-9 overexpression. Western blot analysis was performed to evaluate changes of protein levels and changes of gene level were detected by qRT-PCR in U251 cells.

RESULTS

Matrine suppressed cell viability while induced apoptosis and autophagy in U251 cells. Matrine also decreased circRNA-104075 expression significantly. Overexpression of circRNA-104075 was found to counteract the inhibitory effects of matrine on cell proliferation and promoting effects on apoptosis and autophagy in U251 cells. Moreover, the suppressed Wnt/β-catenin and PI3K/AKT signaling pathways by matrine were activated by circRNA-104075 overexpression. Furthermore, Bcl-9 expression was also down-regulated by matrine treatment. Bcl-9 overexpression elevated the decreased cell proliferation while suppressed the increased apoptosis and autophagy induced by matrine in U251 cells.

CONCLUSION

Taken together, the present findings suggested that matrine induced apoptosis and autophagy through down-regulating circ-104075 and Bcl-9 expression via inhibition of PI3K/AKT and Wnt-β-catenin pathways in glioma cells. The present study provides a foundation for further preclinical and clinical evaluations of matrine as a glioma therapy.

High methylation levels of PCDH10 predict poor prognosis in patients with pancreatic ductal adenocarcinoma

Background

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies and is not a clinically homogeneous disease, but subsets of patients with distinct prognosis and response to therapy can be identified by genome-wide analyses. Mutations in major PDAC driver genes were associated with poor survival. By bioinformatics analysis, we identified protocadherins among the most frequently mutated genes in PDAC suggesting an important role of these genes in the biology of this tumor. Promoter methylation of protocadherins has been suggested as a prognostic marker in different tumors, but in PDAC this epigenetic modification has not been extensively studied. Thus, we evaluated whether promoter methylation of three frequently mutated protocadherins, PCDHAC2, PCDHGC5 and PCDH10 could be used as survival predictors in PDAC patients.

Methods

DNA extracted from 23 PDACs and adjacent non-neoplastic pancreatic tissues were bisulfite treated. Combined Bisulfite Restriction Analysis (COBRA) coupled to denaturing high-performance liquid chromatography (dHPLC) detection and bisulfite genomic sequencing (BGS) were used to determine the presence of methylated CpG dinucleotides in the promoter amplicons analyzed.

Results

In an exploratory analysis, two protocadherins showed the same pattern of CpG methylation in PDAC and adjacent non-neoplastic pancreatic tissues: lack of methylation for PCDHAC2, complete methylation for PCDHGC5. Conversely, the third protocadherin analyzed, PCDH10, showed a variable degree of CpG methylation in PDAC and absence of methylation in adjacent non-neoplastic pancreatic tissues. At Kaplan–Meier analysis, high levels of PCDH10 methylation defined according to the receiver operating characteristic (ROC) curve analysis were significantly associated with worse progression-free survival (PFS) rates (P = 0.008), but not with overall survival (OS). High levels of PCDH10 methylation were a prognostic factor influencing PFS (HR = 4.0: 95% CI, 1.3–12.3; P = 0.016), but not the OS.

Conclusions

In this study, we show for the first time that the methylation status of PCDH10 can predict prognosis in PDAC patients with a significant impact on the outcome in terms of progression-free survival. High levels of PCDH10 promoter methylation could be useful to identify patients at high risk of disease progression, contributing to a more accurate stratification of PDAC patients for personalized clinical management.

Bone marrow MSCs in MDS: contribution towards dysfunctional hematopoiesis and potential targets for disease response to hypomethylating therapy

The study of myelodysplastic syndromes (MDS) in murine models has now indicated the possible involvement of the bone marrow microenvironment in the generation of dysplastic hematopoietic cells. However, there is scant work on patient samples and the role of hypomethylating agents on the bone marrow stromal cells of MDS patients is unclear. We show that human MDS-MSCs exhibit phenotypic, transcriptomic and epigenetic abnormalities. Stimuli provided by MDS-MSCs impaired the growth and function of healthy HSPCs, which is further sustained autonomously in HSPCs for significant periods of time resulting in a failure for active hematopoietic engraftment across primary and secondary transplant recipients (chimerism: 0.34–91% vs 2.78%, engraftment frequencies: at 0.06 ± 0.02 vs full engraftment for MDS-MSC vs healthy groups, respectively). Hypomethylation of MDS-MSCs improved overall engraftment in most of the MDS-MSC groups tested (2/7 with p < 0.01, 3/7 with p < 0.05 and 2/7 with no significant difference). MDS-MSCs that fail to respond to hypomethylating therapy are associated with patients with rapid adverse disease transformation and this further suggests that MDS-MSCs may be an integral part of disease progression and have prognostic value as well as potential as a therapeutic target.

The Cadherin Superfamily in Neural Circuit Assembly

The cadherin superfamily comprises a large, diverse collection of cell surface receptors that are expressed in the nervous system throughout development and have been shown to be essential for the proper assembly of the vertebrate nervous system. As our knowledge of each family member has grown, it has become increasingly clear that the functions of various cadherin subfamilies are intertwined: they can be present in the same protein complexes, impinge on the same developmental processes, and influence the same signaling pathways. This interconnectedness may illustrate a central way in which core developmental events are controlled to bring about the robust and precise assembly of neural circuitry.

Clinical significance of PCDH10 promoter methylation in diffuse large B-cell lymphoma

BACKGROUND

PCDH10, one of the non-clustered protocadherins, is identified as a tumor suppressor gene in many tumors. Recently, promoter methylation of PCDH10 was found in diffuse large B-cell lymphoma (DLBCL) but not in normal lymph nodes, suggesting that its epigenetic aberrance is essential to the lymphomagenesis. However, there are few studies on the clinicopathological relevance and prognostic significance of PCDH10 methylation status in DLBCL.

METHODS

One hundred-seven cases of DLBCL between Jan 2009 and Jul 2010 were selected to extract genomic DNA and perform bisulfite modification. Their methylation status of PCDH10 promoter were accessed by methylation-specific PCR (MSP) with methylated and unmethylated primers. Analysis of overall survival and clinicopathological correlation were conducted.

RESULTS

PCDH10 hypermethylation were found in 54.2% (58/107) of DLBCL cases, but only 12.5% (1/8) in reactive lymph node/follicular hyperplasia. In RCHOP-treated cohort, promoter methylation of PCDH10 is an independent prognostic indicator of worse overall survival (p = 0.017; HR 4.045; 95%CI 1.287-12.711) and worse progress-free survival (p = 0.014; HR 2.977; 95%CI 1.245-7.119). Whereas, PCDH10 hypermethylation wasn't correlated with MYC translocation and cell of origin classification using Hans model.

CONCLUSIONS

PCDH10 methylation status could serve as a valuable biomarker for risk classification, and a potential therapeutic target for demethylating drugs in DLBCL in the future.

Regulation of Wnt signaling by protocadherins

The ∼70 protocadherins comprise the largest group within the cadherin superfamily. Their diversity, the complexity of the mechanisms through which their genes are regulated, and their many critical functions in nervous system development have engendered a growing interest in elucidating the intracellular signaling pathways through which they act. Recently, multiple protocadherins across several subfamilies have been implicated as modulators of Wnt signaling pathways, and through this as potential tumor suppressors. Here, we review the extant data on the regulation by protocadherins of Wnt signaling pathways and components, and highlight some key unanswered questions that could shape future research.

PCDH8 inhibits glioma cell proliferation by negatively regulating the AKT/GSK3β/β-catenin signaling pathway

Protocadherin-8 (PCDH8), a member of the protocadherin superfamily of proteins, is frequently lost in numerous types of cancer. However, the role that PCDH8 serves in human glioma, and the molecular mechanisms underlying this, remain unclear. Data from the present study demonstrated that the expression levels of PCDH8 mRNA and protein were significantly decreased in human glioma tissue compared with normal brain tissue. This suggested that PCDH8 is associated with the development of glioma. Thus, the role of PCDH8 in glioma cell proliferation was investigated by silencing and overexpressing PCDH8 in U251 glioma cells. Overexpression of PCDH8 significantly inhibited glioma cell proliferation, while silencing of PCDH8 using small interfering RNA promoted glioma cell proliferation. Restoration of PCDH8 decreased phosphorylated (p)-Rac-α serine/threonine-protein kinase (AKT) [Threonine (T)308/Serine (S)473] and p-glycogen synthase kinase-3β (p-GSK3β) (S9) protein expression, thereby reducing the level of β-catenin when compared with the control. By contrast, silencing of PCDH8 increased levels of p-AKT (T308/S473) and p-GSK3β (S9), thereby increasing the level of β-catenin. In conclusion, the results of the present study suggested that PCDH8 suppressed glioma cell proliferation, and that the loss of PCDH8 may stimulate the proto-oncogene Wnt/β-catenin signaling pathway and therefore promote glioma cell proliferation.

PCDH18 is frequently inactivated by promoter methylation in colorectal cancer

Protocadherin18 (PCDH18) was found to be preferentially methylated and inactivated in colorectal cancer (CRC) using bioinformatics tools. However, its biologic role in tumorgenesis remains unclear. Herein, we aimed to elucidate its epigenetic regulation and biological functions in CRC. The methylation status of PCDH18 was significant higher in CRC tissues than in adjacent non-tumor tissues (median, 15.17% vs. median, 0.4438%). Expression level of PCDH18 was significantly lower in primary CRCs than in nonmalignant tissues. Importantly, methylation status of PCDH18 in cell-free DNA of CRC patients was also significantly higher than in healthy subjects. PCDH18 was readily expressed in NCM460 cells, but downregulated in 100% (4/4) of CRC cell lines by promoter methylation, despite its expression could be restored through demethylation treatment. Overexpression of PCDH18 suppressed CRC cell viability, colony formation and migration. Meanwhile, the depletion of PCDH18 by siRNA in NCM460 cells enhanced the colonogenicity and migration ability and promoted β-catenin nuclear accumulation, whereas it inhibited cell cycle arrest. These effects were associated with upregulation of phospho-GSK-3β and cyclin D1, and downregulation of caspase3 and p21. Our results suggested that PCDH18 was a putative tumor suppressor with epigenetic silencing in CRC and a potential biomarker for CRC diagnosis.

Overexpression of Protocadherin-10 in Transthyretin-Related Familial Amyloidotic Polyneuropathy

Overwhelming data suggest that oncogenic and neurodegenerative pathways share several altered cellular responses to insults such as oxidative stress, extracellular matrix remodeling, inflammation, or cell dyscommunication. Protocadherin-10 (Pcdh10) is an adhesion molecule found to protect against tumorigenesis and essential for axonal elongation and actin dynamics during development. Here, by using genome microarrays we identified for the first time Pcdh10 up-regulation in tissues from transgenic mouse models, cultured Schwann cells, and human samples from a familial form of peripheral neuropathy (familial amyloidotic polyneuropathy). Familial amyloidotic polyneuropathy is characterized by poor functional recovery and impaired nerve regenerative response after misfolding and deposition in the peripheral nervous system of mutant transthyretin. Not only increased transcriptional and translational Pcdh10 levels occurred in axons and Schwann cells of nerves with deposited transthyretin aggregates but the pattern also extended to associated cues of axon guidance like neuropilin-1 and F-actin. These findings suggest that Pcdh10 may influence subcellular actin cytoskeletal organization and axon-axon interactions in the course of familial amyloidotic polyneuropathy. Moreover, when preventing nonfibrillar transthyretin deposition with anakinra or transthyretin siRNA, Pcdh10 protein levels were reduced, highlighting its potential as a novel disease biomarker. Whether Pcdh10 overexpression in familial amyloidotic polyneuropathy represents a protective or deleterious response, enhancing survival or promoting cell death will need further investigation.

PCDH10 gene inhibits cell proliferation and induces cell apoptosis by inhibiting the PI3K/Akt signaling pathway in hepatocellular carcinoma cells

Protocadherin10 (PCDH10), a member of the non-clustered protocadherin (PCDH) family, functions as a tumor-suppressor gene in many cancers. Previous studies have demonstrated that the expression of PCDH10 was noticeably downregulated in the tissue and cells of hepatocellular carcinoma (HCC), when compared to those in normal liver tissue. The decreased PCDH10 expression in HCC was correlated with the aberrant methylation status of PCDH10 promoter. However, the biological functions and molecular mechanism of PCDH10 in HCC have yet to be elucidated. The aim of the present study was to identify the biological function and mechanisms of PCDH10 in HCC. Quantitative real-time polymerase chain reaction was used to detect the expression of PCDH10 in HCC cells with decreased expression of PCDH10 which were transfected with plasmid pcDNA3.1-PCDH10 or pcDNA3.1-vector using Lipofectamine 2000. The biological effects of PCDH10 in HCC cells were detected by CCK-8, colony formation and flow cytometric assays. Western blot and co-immunoprecipitation (Co-IP) assays were performed to explore the mechanism of PCDH10 in HCC cells. PCDH10 expression was downregulated in the HCC cells (HepG2, HuH7, HuH1, and SNU387) when compared to the normal liver cells (L02). Upregulation of PCDH10 inhibited cell proliferation and induced cell apoptosis in the HCC cells. More importantly, we revealed that PCDH10 inhibited the PI3K/Akt signaling pathway thus carrying out its suppressive function in HCC. This study provides insights into the tumorigenesis and progression of HCC, and puts forward the novel hypothesis that PCDH10 could be a new biomarker for HCC, or that combined with other molecular markers could increase the specificity and sensitivity of diagnostic tests for HCC. Restoration of PCDH10 could be a valuable therapeutic target for HCC.

Epigenetic silencing of protocadherin 10 in colorectal cancer

Colorectal cancer (CRC) is one of the most common types of malignant tumor in the world and occurs through a multi-step process resulting from the accumulation of genetic and epigenetic alterations of the genome. Although the molecular mechanisms of the pathogenesis of CRC remain unclear, the inactivation of tumor suppressor genes (TSGs) through promoter methylation serves an important role. Aberrant methylation is a well-defined marker of CRC. At present, the epigenetic silencing of protocadherin 10 (PCDH10) has been identified as an important TSG with key roles in colorectal carcinogenesis, invasion and metastasis as a frequent and early event. Advances in gene methylation detection in tumor tissues and body fluids have led to the development of non-invasive screening methods for CRC. The present study aimed to review the epigenetic alteration of PCDH10 in CRC development, and the potential of PCDH10 to be a non-invasive biomarker for CRC.

Aberrant expression and functions of protocadherins in human malignant tumors

Protocadherins (PCDHs) are a group of transmembrane proteins belonging to the cadherin superfamily and are subdivided into "clustered" and "non-clustered" groups. PCDHs vary in both structure and interaction partners and thus regulate multiple biological responses in complex and versatile patterns. Previous researches showed that PCDHs regulated the development of brain and were involved in some neuronal diseases. Recently, studies have revealed aberrant expression of PCDHs in various human malignant tumors. The down-regulation or absence of PCDHs in malignant cells has been associated with cancer progression. Further researches suggest that PCDHs may play major functions as tumor suppressor by inhibiting the proliferation and metastasis of cancer cells. In this review, we focus on the altered expression of PCDHs and their roles in the development of cancer progression. We also discuss the potential mechanisms, by which PCDHs are aberrantly expressed, and its implications in regulating cancers.

Protocadherin-10 acts as a tumor suppressor gene, and is frequently downregulated by promoter methylation in pancreatic cancer cells

Protocadherin-10 (PCDH10), a member of non-clustered protocadherin family which plays important roles in calcium-dependent cell-cell signal transduction and adhesion. PCDH10 functions as a tumor suppressor gene and its expression is downregulated by promoter methylation in many malignances. In the present study, we explored PCDH10 expression and promoter methylation status, and its biological effects in pancreatic cancer cells, and furthermore, we explored the mechanism of PCDH10 preliminary in pancreatic cancer cells. the mRNA level of PCDH10 was detected by semi-quantitative reverse transcription PCR and promoter methylation status examined by methylation-specific PCR in the pancreatic cancer cells (Capan-1, Panc-1, AsPC-1 and BxPC-3) as well as the human normal pancreatic ductal epithelial cells HPDE6-C7 which was used as a control. The human pancreatic cells were transfected with plasmid pcDNA3.1-PCDH10 or pcDNA3.1 by lipofectamine 2000. The biological function of PCDH10 in pancreatic cancer cells was determined by CCK-8 assay, colony formation assay, flow cytometry, Transwell invasion assay and wound-healing assay. The levels of apoptosis related proteins were examined by western blotting. PCDH10 expression was obviously downregulated in the pancreatic cancer cells (Capan-1, Panc-1, BxPC-3) compared to the normal pancreatic ductal epithelial cells. PCDH10 promoter methylation was observed in the two pancreatic cancer cells Capan-1 and BxPC-3,and the expression of PCDH10 could be restored after treating with 5-aza-2'-deoxycytidine and trichostatin A in the two cell types. Overexpression of PCDH10 can inhibit the proliferation, migration, invasion ability of pancreatic cancer cells and induce apoptosis. Ectopic expression of PCDH10 could increase the levels of PARP, caspase-3, caspase-9 and decrease the level of bcl-2, AKT and p-AKT. PCDH10 acts as a tumor suppressor gene, and is frequently down-regulated by promoter methylation in pancreatic cancer cells. PCDH10 may induce cancer cell apoptosis via the AKT pathway.

Protocadherin 10 inhibits cell proliferation and induces apoptosis via regulation of DEP domain containing 1 in endometrial endometrioid carcinoma

Endometrial cancer is the most common gynecologic malignancy and about 80% of these cancers are endometrial endometrioid carcinoma (EEC). Previously, we have demonstrated that protocadherin 10 (PCDH10) is a tumor suppressor gene in EEC, and in this study we further explored the molecular mechanisms of PCDH10 in EEC. We first detect the PCDH10 expression in EEC tissues and then investigate the mechanism in two EEC cell lines. The mRNA and protein expression levels were measured by quantitative real time PCR (qRT-PCR) and western blot, respectively; Cell growth was determined by MTS, CCK-8 and colony formation assays; Cell cycle was determined by flow cytometry, and cell apoptosis was examined by flow cytometry and TUNEL assay. The downstream mediator of PCHD10 was confirmed by Topflash luciferase reporter assay. QRT-PCR and western blot results showed that PCDH10 was down-regulated in EEC clinical tissues. Restoration of PCDH10 suppressed cell growth and induced apoptosis in EEC cells. Dishevelled, EGL-10 and Pleckstrin domain containing 1 (DEPDC1) was a potential downstream mediator of PCDH10 as revealed by RNA-sequencing, and mechanistic studies suggested that DEPDC1 is a downstream mediator and promotes cell growth and induces apoptosis in EEC cells. Western blot further showed that PCDH10 restoration activate apoptotic signaling pathway via caspase signaling in both EEC cell lines and EEC clinical tissues. Collectively, our results suggest that PCDH10-DEPDC1-caspase signaling may be a novel regulatory axis in EEC development and it will be of great interest to explore the clinical significance of PCDH10 and DEPDC1 in the future.