Angelica sinensis polysaccharide suppresses the Wnt/ß-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 ß-catenin and phosphorylated glycogen synthase kinase-3ß (p-GSK-3ß) 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/ß-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.

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.

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.

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.

ASD/OCD-Linked Protocadherin-10 Regulates Synapse, But Not Axon, Development in the Amygdala and Contributes to Fear- and Anxiety-Related Behaviors.

The Protocadherin-10 (PCDH10) gene is associated with autism spectrum disorder (ASD), obsessive-compulsive disorder (OCD), and major depression (MD). The PCDH10 protein is a homophilic cell adhesion molecule that belongs to the δ2-protocadherin family. PCDH10 is highly expressed in the developing brain, especially in the basolateral nucleus of the amygdala (BLA). However, the role of PCDH10 in vivo has been debatable: one paper reported that a Pcdh10 mutant mouse line showed changes in axonal projections; however, another Pcdh10 mutant mouse line was reported to have failed to detect axonal phenotypes. Therefore, the actual roles of PCDH10 in the brain remain to be elucidated. We established a new Pcdh10 KO mouse line using the CRISPR/Cas9 system, without inserting gene cassettes to avoid nonspecific effects, examined the roles of PCDH10 in the brain, and studied the behavioral consequences of Pcdh10 inactivation. Here, we show that Pcdh10 KO mice do not show defects in axonal development. Instead, we find that Pcdh10 KO mice exhibit impaired development of excitatory synapses in the dorsal BLA. We further demonstrate that male Pcdh10 KO mice exhibit reduced anxiety-related behaviors, impaired fear conditioning, decreased stress-coping responses, and mildly impaired social recognition and communication. These results indicate that PCDH10 plays a critical role in excitatory synapse development, but not axon development, in the dorsal BLA and that PCDH10 regulates anxiety-related, fear-related, and stress-related behaviors. Our results reveal the roles of PCDH10 in the brain and its relationship to relevant psychiatric disorders such as ASD, OCD, and MD.SIGNIFICANCE STATEMENTProtocadherin-10 (PCDH10) encodes a cell adhesion molecule and is implicated in autism spectrum disorder (ASD), obsessive-compulsive disorder (OCD), and major depression (MD). PCDH10 is highly expressed in the basolateral nucleus of the amygdala (BLA). However, the phenotypes of previously published Pcdh10 mutant mice are debatable, and some are possibly because of the nonspecific effects of the LacZ/Neo cassette inserted in the mice. We have generated a new Pcdh10 mutant mouse line without the LacZ/Neo cassette. Using our new mouse line, we reveal the roles of PCDH10 for excitatory synapse development in the BLA. The mutant mice exhibit anxiety-related, fear-related, and stress-related behaviors, which are relevant to ASD, OCD, and MD, suggesting a possible treatment strategy for such psychiatric disorders.

A single-cell transcriptome of mesenchymal stromal cells to fabricate bioactive hydroxyapatite materials for bone regeneration.

The osteogenic microenvironment of bone-repairing materials plays a key role in accelerating bone regeneration but remains incompletely defined, which significantly limits the application of such bioactive materials. Here, the transcriptional landscapes of different osteogenic microenvironments, including three-dimensional (3D) hydroxyapatite (HA) scaffolds and osteogenic medium (OM), for mesenchymal stromal cells (MSCs) in vitro were mapped at single-cell resolution. Our findings suggested that an osteogenic process reminiscent of endochondral ossification occurred in HA scaffolds through sequential activation of osteogenic-related signaling pathways, along with inflammation and angiogenesis, but inhibition of adipogenesis and fibrosis. Moreover, we revealed the mechanism during OM-mediated osteogenesis involves the ZBTB16 and WNT signaling pathways. Heterogeneity of MSCs was also demonstrated. In vitro ossification of LRRC75A+ MSCs was shown to have better utilization of WNT-related ossification process, and PCDH10+ MSCs with superiority in hydroxyapatite-related osteogenic process. These findings provided further understanding of the cellular activity modulated by OM conditions and HA scaffolds, providing new insights for the improvement of osteogenic biomaterials. This atlas provides a blueprint for research on MSC heterogeneity and the osteogenic microenvironment of HA scaffolds and a database reference for the application of bioactive materials for bone regeneration.

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/ß-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.

Disruption of PCDH10 and TNRC18 Genes due to a Balanced Translocation.

Balanced chromosomal rearrangements are usually associated with a normal phenotype, although in some individuals, phenotypic alterations are observed. In these patients, molecular characterization of the breakpoints can reveal the pathogenic mechanism, providing the annotation of disease-associated loci and a better genotype-phenotype correlation. In this study, we describe a patient with a balanced reciprocal translocation between 4q27 and 7p22 associated with neurodevelopmental delay. We performed cytogenetic evaluation, next-generation sequencing of microdissected derivative chromosomes, and Sanger sequencing of the junction points to define the translocation's breakpoints at base pair resolution. We found that the PCDH10 and TNRC18 genes were disrupted by the breakpoints at chromosomes 4 and 7, respectively, with the formation of chimeric genes at the junction points. Gene expression studies in the patient's peripheral blood showed reduced expression of TNRC18, a gene with unknown function and clinical significance. PCDH10 plays a role in the development of the nervous system and might be involved with the patient's neurodevelopmental delay. In this study, the full molecular characterization of the junction points was shown as an efficient tool for fine breakpoint mapping in balanced translocations in order to unmask gene disruptions and investigate the potential pathogenic role of the disrupted genes.

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.

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.

Protocadherin 10 alters γ oscillations, amino acid levels, and their coupling; baclofen partially restores these oscillatory deficits.

Approximately one in 45 children have been diagnosed with Autism Spectrum Disorder (ASD), which is characterized by social/communication impairments. Recent studies have linked a subset of familial ASD to mutations in the Protocadherin 10 (Pcdh10) gene. Additionally, Pcdh10's expression pattern, as well as its known role within protein networks, implicates the gene in ASD. Subsequently, the neurobiology of mice heterozygous for Pcdh10 (Pcdh10+/-) has been investigated as a proxy for ASD. Male Pcdh10+/- mice have demonstrated sex-specific deficits in social behavior, recapitulating the gender bias observed in ASD. Furthermore, in vitro slice preparations of these Pcdh10+/- mice demonstrate selective decreases to high frequency electrophysiological responses, mimicking clinical observations. The direct in vivo ramifications of such decreased in vitro high frequency responses are unclear. As such, Pcdh10+/- mice and their wild-type (WT) littermates underwent in vivo electrocorticography (ECoG), as well as ex vivo amino acid concentration quantification using High Performance Liquid Chromatography (HPLC). Similar to the previously observed reductions to in vitro high frequency electrophysiological responses in Pcdh10+/- mice, male Pcdh10+/- mice exhibited reduced gamma-band (30-80Hz), but not lower frequency (10 and 20Hz), auditory steady state responses (ASSR). In addition, male Pcdh10+/- mice exhibited decreased signal-to-noise-ratio (SNR) for high gamma-band (60-100Hz) activity. These gamma-band perturbations for both ASSR and SNR were not observed in females. Administration of a GABAB agonist remediated these electrophysiological alterations among male Pcdh10+/-mice. Pcdh10+/- mice demonstrated increased concentrations of GABA and glutamine. Of note, a correlation of auditory gamma-band responses with underlying GABA concentrations was observed in WT mice. This correlation was not present in Pcdh10+/- mice. This study demonstrates the role of Pcdh10 in the regulation of excitatory-inhibitory balance as a function of GABA in ASD.

Promoter methylation of PCDH10 by HOTAIR regulates the progression of gastrointestinal stromal tumors.

HOTAIR, a long non-coding RNA (lncRNA), plays a crucial role in tumor initiation and metastasis by interacting with the PRC2 complex and the modulation of its target genes. The role of HOTAIR in gastrointestinal stromal tumors (GISTs) is remains unclear. Herein we investigate the mechanism of HOTAIR in the genesis and promotion of GISTs. The expression of HOTAIR was found to be higher in surgically resected high-risk GISTs than that in low- and intermediate-risk GISTs. Using GIST-T1 and GIST882 cells, we demonstrated that HOTAIR repressed apoptosis, was associated with cell cycle progression, and controlled the invasion and migration of GIST cells. Using a gene expression microarray and lists of HOTAIR-associated candidate genes, we suggested that protocadherin 10 (PCDH10) is a key molecule. PCDH10 expression was significantly decreased in GIST-T1 and GIST882 cells, possibly as a consequence of hypermethylation. We observed that HOTAIR induced PCDH10 methylation in a SUZ12-dependent manner. In this study, we found that the malignant character of GISTs was initiated and amplified by PCDH10 in a process regulated by HOTAIR. In summary, our findings imply that PCDH10 and HOTAIR may be useful markers of disease progression and therapeutic targets.

Aberrant methylation of PCDH10 and RASSF1A genes in blood samples for non-invasive diagnosis and prognostic assessment of gastric cancer.

Background. Assessment of DNA methylation of specific genes is one approach to the diagnosis of cancer worldwide. Early stage detection is necessary to reduce the mortality rate of cancers, including those occurring in the stomach. For this purpose, tumor cells in circulating blood offer promising candidates for non-invasive diagnosis. Transcriptional inactivation of tumor suppressor genes, like PCDH10 and RASSF1A, by methylation is associated with progression of gastric cancer, and such methylation can therefore be utilized as a biomarker. Methods. The present research was conducted to evaluate DNA methylation in these two genes using blood samples of gastric cancer cases. Clinicopathological data were also analyzed and cumulative survival rates generated for comparison. Results. High frequencies of PCDH10 and RASSF1A methylations in the gastric cancer group were noted (94.1% and 83.2%, respectively, as compared to 2.97% and 5.45% in 202 matched controls). Most patients (53.4%) were in severe stage of the disease, with a median survival time of 8.4 months after diagnosis. Likewise, the patients with metastases, or RASSF1A and PCDH10 methylations, had median survival times of 7.3, 7.8, and 8.4 months, respectively. A Kaplan-Meier analysis showed that cumulative survival was significantly lower in those cases positive for methylation of RASSF1A than in their negative counterparts. Similarly, whereas almost 100% of patients positive for PCDH10 methylation had died after five years, none of the negative cases died over this period. Notably, the methylations of RASSF1A and PCDH10 were found to be higher in the late-stage patients and were also significantly correlated with metastasis and histology. Conclusions. PCDH10 and RASSF1A methylations in blood samples can serve as potential non-invasive diagnostic indicators in blood for gastric cancer. In addition to RASSF1A methylation, tumor stage proved to be a major prognostic factor in terms of survival rates.

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.

Evaluating the clinical feasibility: The direct bisulfite genomic sequencing for examination of methylated status of protocadherin10 (PCDH10) promoter to predict the prognosis of gastric cancer.

OBJECTIVE: To elucidate the clinical significance of the methylated status of CpG site count of PCDH10 promoter in the survival prediction in gastric cancer (GC). METHODS: In the previous study, we demonstrated that the methylated CpG site count was significantly associated with the overall survival (OS) of GC patients by using the bisulfite genomic sequencing (BGS) with no less than five clones per sample. It was so complex and expensive for patients to undergo the BGS clones. In this study, we detected the different CpG site counts (hypermethylated and hypomethylated) of PCDH10 DNA promoter in GC samples of 471 patients by directly bisulfite genomic sequencing (D-BGS) without any clone. Furthermore, we evaluated the relationships between the methylated status of PCDH10 promoter and OS. RESULTS: Two hundred and fifty-seven of 471 (54.6%) GC patients were identified to present with PCDH10 promoter methylation by D-BGS. Patients who presented with 5 or more methylated CpG site counts of PCDH10 promoter had significantly poorer prognosis than patients who with less than 5 methylated CpG site counts of PCDH10 promoter (p= 0.039). With the multivariate survival analysis, we demonstrated that T stage, N stage and the hypermethylated CpG site counts of PCDH10 DNA promoter were the independent predictors of OS of GC patients. In addition, the hypermethylated CpG site counts of PCDH10 DNA promoter had smaller Akaike information criterion (AIC) and Bayesian information criterion (BIC) values than the other two independent predictors of the OS, indicating the hypermethylated CpG site counts of PCDH10 DNA promoter as the best prognostic predictor of GC. CONCLUSIONS: Our present findings suggested that the hypermethylated CpG site counts of PCDH10 DNA promoter for evaluating the prognosis of GC was reasonable by using the D-BGS.

PCDH10, a novel p53 transcriptional target in regulating cell migration.

Cell cycle arrest, senescence and apoptosis are commonly regarded as the major tumor suppression mechanisms of p53. However, accumulating evidence indicates that loss of these canonical functions is not sufficient for tumor formation, highlighting the complexity of p53-mediated tumor suppression. PCDH10 belongs to a proto cadherin protein family and is a potential tumor suppressor protein as the dysregulation of PCDH10 gene frequently existed in multiple human tumors. Here, we found that PCDH10 is a transcriptional target of p53 and that the levels of PCDH10 expression can be induced by wild type p53 but not mutant p53 in a number of human cancer cell lines. Moreover, we identified a p53 consensus binding site located in the PCDH10 promoter region that is responsive to p53 regulation. Although upregulation of PCDH10 has no obvious effect on growth arrest or apoptosis in human cells, PCDH10 exhibits inhibitory roles in cancer cell motility and cell migration. These results suggest an important role of p53 in regulating tumor cell migration through activating PCDH10 expression and support the notion that non-canonical activities of p53 may contribute to its tumor suppressor function in vivo.

Protocadherin 10 suppresses tumorigenesis and metastasis in colorectal cancer and its genetic loss predicts adverse prognosis.

Protocadherin 10 (PCDH10), a novel tumor suppressor gene in human cancers, is located in a common deleted region at chromosome 4q28 in colorectal cancer (CRC). This study aimed to ascertain the genetic loss of PCDH10 and its clinical relevance in CRC and to explore the tumor suppressor function of PCDH10. The genetic deletion of PCDH10 was determined in 171 pairs of primary tumors and corresponding normal mucosae by loss of heterozygosity study. In total, 53 carcinomas were positive for allelic loss of PCDH10. The genetic aberration was significantly associated with tumor progression and distant metastasis (p = 0.021 and p = 0.018, respectively) and was an independent predictor of poor survival for CRC patients (p = 0.005). Expression of PCDH10 gene was silenced or markedly down-regulated in all of 12 CRC cell lines tested and in 41 of 53 colorectal carcinomas compared with their matched normal mucosae. Ectopic expression of PCDH10 suppressed cancer cell proliferation, anchorage-independent growth, migration and invasion in vitro. Subcutaneous injection of PCDH10-expressing CRC cells into SCID mice revealed the reduction of tumor growth compared with that observed in mock-inoculated mice. Furthermore, through intrasplenic implantation, the re-expression of PCDH10 in silenced cells restrained liver metastasis and improved survival in SCID mice. In conclusion, PCDH10 is a pivotal tumor suppressor in CRC, and the loss of its function promotes not only tumor progression but also liver metastasis. In addition, the genetic deletion of PCDH10 represents an adverse prognostic marker for the survival of patients with CRC.

PCDH10 is required for the tumorigenicity of glioblastoma cells.

Protocadherin10 (PCDH10)/OL-protocadherin is a cadherin-related transmembrane protein that has multiple roles in the brain, including facilitating specific cell-cell connections, cell migration and axon guidance. It has recently been reported that PCDH10 functions as a tumor suppressor and that its overexpression inhibits proliferation or invasion of multiple tumor cells. However, the function of PCDH10 in glioblastoma cells has not been elucidated. In contrast to previous reports on other tumors, we show here that suppression of the expression of PCDH10 by RNA interference (RNAi) induces the growth arrest and apoptosis of glioblastoma cells in vitro. Furthermore, we demonstrate that knockdown of PCDH10 inhibits the growth of glioblastoma cells xenografted into immunocompromised mice. These results suggest that PCDH10 is required for the proliferation and tumorigenicity of glioblastoma cells. We speculate that PCDH10 may be a promising target for the therapy of glioblastoma.

Gene methylation in gastric cancer.

Gastric cancer is one of the most common malignancies and remains the second leading cause of cancer-related death worldwide. Over 70% of new cases and deaths occur in developing countries. In the early years of the molecular biology revolution, cancer research mainly focuses on genetic alterations, including gastric cancer. Epigenetic mechanisms are essential for normal development and maintenance of tissue-specific gene expression patterns in mammals. Disruption of epigenetic processes can lead to altered gene function and malignant cellular transformation. Recent advancements in the rapidly evolving field of cancer epigenetics have shown extensive reprogramming of every component of the epigenetic machinery in cancer, including DNA methylation, histone modifications, nucleosome positioning, noncoding RNAs, and microRNAs. Aberrant DNA methylation in the promoter regions of gene, which leads to inactivation of tumor suppressor and other cancer-related genes in cancer cells, is the most well-defined epigenetic hallmark in gastric cancer. The advantages of gene methylation as a target for detection and diagnosis of cancer in biopsy specimens and non-invasive body fluids such as serum and gastric washes have led to many studies of application in gastric cancer. This review focuses on the most common and important phenomenon of epigenetics, DNA methylation, in gastric cancer and illustrates the impact epigenetics has had on this field.

Delta Protocadherin 10 is Regulated by Activity in the Mouse Main Olfactory System.

Olfactory sensory neurons (OSNs) are thought to use activity-dependent and independent mechanisms to regulate the expression of axon guidance genes. However, defining the molecular mechanisms that underlie activity-dependent OSN guidance has remained elusive. Only a handful of genes have been identified whose expression is regulated by activity. Interestingly, all of these genes have been shown to play a role in OSN axon guidance, underscoring the importance of identifying other genes regulated by activity. Furthermore, studies suggest that more than one downstream mechanism regulates target gene expression. Thus, both the number of genes regulated by activity and how many total mechanisms control this expression are not well understood. Here we identify delta protocadherin 10 (pcdh10) as a gene regulated by activity. Delta protocadherins are members of the cadherin superfamily, and pcdh10 is known to be important for axon guidance during development. We show pcdh10 is expressed in the nasal epithelium and olfactory bulb in patterns consistent with providing guidance information to OSNs. We use naris occlusion, genetic manipulations, and pharmacological assays to show pcdh10 can be regulated by activity, consistent with activation via the cyclic nucleotide-gated channel. Transgenic analysis confirms a potential role for pcdh10 in OSN axon guidance.