Copine1 C2 domains have a critical calcium-independent role in the neuronal differentiation of hippocampal progenitor HiB5 cells

CPNE1 mediates glycolysis and metastasis of breast cancer through activation of PI3K/AKT/HIF-1α signaling

CPNE1 regulates multiple signaling pathways and can stimulate cell proliferation and differentiation by activating the AKT-mTOR signaling pathway. In addition, CPNE1 is associated with various cancers; however, its role in breast cancer, particularly in TNBC, has not been fully elucidated. Our study aimed to reveal the impact of the CPNE1/PI3K/AKT/HIF-1α axis on TNBC. We first measured the expression of CPNE1 in the tumor tissues of TNBC patients and examined its prognostic value. Subsequently, we used sh-CPNE1 and overexpression vectors to transfect TNBC cell lines and analyzed cell viability, migration, and invasive abilities using colony formation and CCK-8 assays. Metabolites were analyzed through metabolomics. We found that higher expression of CPNE1 predicted poor prognosis in TNBC patients. Knockdown of CPNE1 reduced the viability, migration, invasion, and proliferation capabilities of TNBC cells. Furthermore, metabolomics analysis showed that glucose metabolism was the most dominant pathway, and knockdown of CPNE1 significantly limited the glycolytic activity of TNBC cells. We verified these conclusions in mouse models. Additionally, we overexpressed CPNE1 and treated TNBC cell lines with a PI3K inhibitor (LY294002). The results indicated that CPNE1 promoted aerobic glycolysis in TNBC cells through the PI3K/AKT/HIF-1α signaling pathway. This suggests that CPNE1 regulates cell glycolysis and participates in the development of TNBC. Our study may provide a new therapeutic target for TNBC treatment.

Regulatory mechanisms and therapeutic potential of JAB1 in neurological development and disorders

c-Jun activation domain binding protein-1 (JAB1) is a multifunctional regulator that plays vital roles in diverse cellular processes. It regulates AP-1 transcriptional activity and also acts as the fifth component of the COP9 signalosome complex. While JAB1 is considered an oncoprotein that triggers tumor development, recent studies have shown that it also functions in neurological development and disorders. In this review, we summarize the general features of the JAB1 gene and protein, and present recent updates on the regulation of JAB1 expression. Moreover, we also highlight the functional roles and regulatory mechanisms of JAB1 in neurodevelopmental processes such as neuronal differentiation, synaptic morphogenesis, myelination, and hair cell development and in the pathogenesis of some neurological disorders such as Alzheimer's disease, multiple sclerosis, neuropathic pain, and peripheral nerve injury. Furthermore, current challenges and prospects are discussed, including updates on drug development targeting JAB1.

Comprehensive analysis of prognostic value, immune implication and biological function of CPNE1 in clear cell renal cell carcinoma

Background: Elevated expression of Copine-1 (CPNE1) has been proved in various cancers; however, the underlying mechanisms by which it affects clear cell renal cell carcinoma (ccRCC) are unclear.

Methods: In this study, we applied multiple bioinformatic databases to analyze the expression and clinical significance of CPNE1 in ccRCC. Co-expression analysis and functional enrichment analysis were investigated by LinkedOmics, cBioPortal and Metascape. The relationships between CPNE1 and tumor immunology were explored using ESTIMATE and CIBERSORT method. In vitro experiments, CCK-8, wound healing, transwell assays and western blotting were conducted to investigate the effects of gain- or loss-of-function of CPNE1 in ccRCC cells.

Results: The expression of CPNE1 was notably elevated in ccRCC tissues and cells, and significantly correlated with grade, invasion range, stage and distant metastasis. Kaplan–Meier and Cox regression analysis displayed that CPNE1 expression was an independent prognostic factor for ccRCC patients. Functional enrichment analysis revealed that CPNE1 and its co-expressed genes mainly regulated cancer-related and immune-related pathways. Immune correlation analysis showed that CPNE1 expression was significantly related to immune and estimate scores. CPNE1 expression was positively related to higher infiltrations of immune cells, such as CD8+ T cells, plasma cells and regulatory T cells, exhibited lower infiltrations of neutrophils. Meanwhile, elevated expression of CPNE1 was characterized by high immune infiltration levels, increased expression levels of CD8+ T cell exhaustion markers (CTLA4, PDCD1 and LAG3) and worse response to immunotherapy. In vitro functional studies demonstrated that CPNE1 promoted proliferation, migration and invasion of ccRCC cells through EGFR/STAT3 pathway.

Conclusion: CPNE1 is a reliable clinical predictor for the prognosis of ccRCC and promotes proliferation and migration by activating EGFR/STAT3 signaling. Moreover, CPNE1 significantly correlates with immune infiltration in ccRCC.

CPNE1 silencing inhibits cell proliferation and accelerates apoptosis in human gastric cancer

Gastric cancer is a heterogeneous disease accompanied by the alteration of various causative genes. The discovery of molecular targets and potential mechanisms of gastric cancer is valuable. Here we explored the biological function of CPNE1 and its molecular mechanisms in gastric cancer. Immunohistochemistry and Kaplan-Meier plotter database were used to identify that CPNE1 was upregulated in human gastric cancer and high expression of CPNE1 suggested a worse prognosis. Silencing CPNE1 could effectively suppress tumor proliferation, accelerate cell apoptosis and arrest cell cycle in vitro. CPNE1 knockdown mediating apoptosis by PARP-1 cleavage via caspase-3 and -7 activation through cytochrome c release from mitochondria in gastric cancer cells. Xenograft mouse model showed that targeted inhibition of CPNE1 slowed down the rate of tumor growth in vivo. We also verified that CPNE1 knockdown inhibited the activation of MAPK pathway mediated by DDIT3-FOS-MKNK2 axis. Specific inhibitor of DDIT3-FOS-MKNK2 axis could suppress gastric cancer cell proliferation, concomitant with knockdown of CPNE1. In conclusion, CPNE1 silencing inhibited gastric cancer growth via deactivating DDIT3-FOS-MKNK2 axis, which indicated that CPNE1 might serve as a therapeutic target for gastric cancer.

CPNE1 promotes non-small cell lung cancer progression by interacting with RACK1 via the MET signaling pathway

Background

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer and the most lethal tumour worldwide. Copine 1 (CPNE1) was identified as a novel oncogene in NSCLC in our previous study. However, its specific function and relative mechanisms remain poorly understood.

Methods

The biological role of CPNE1 and RACK1 in NSCLC was investigated using gene expression knockdown and overexpression, cell proliferation assays, clonogenic assays, and Transwell assays. The expression levels of CPNE1, RACK1 and other proteins were determined by western blot analysis. The relationship between CPNE1 and RACK1 was predicted and investigated by mass spectrometry analysis, immunofluorescence staining, and coimmunoprecipitation. NSCLC cells were treated with a combination of a MET inhibitor and gefitinib in vitro and in vivo.

Results

We found that CPNE1 facilitates tumorigenesis in NSCLC by interacting with RACK1, which further induces activation of MET signaling. CPNE1 overexpression promoted cell proliferation, migration, invasion and MET signaling in NSCLC cells, whereas CPNE1 knockdown produced the opposite effects. In addition, the suppression of the enhancing effect of CPNE1 overexpression on tumorigenesis and MET signaling by knockdown of RACK1 was verified. Moreover, compared to single-agent treatment, dual blockade of MET and EGFR resulted in enhanced reductions in the tumour volume and downstream signaling in vivo.

Conclusions

Our findings show that CPNE1 promotes tumorigenesis by interacting with RACK1 and activating MET signaling. The combination of a MET inhibitor with an EGFR-TKI attenuated tumour growth more significantly than either single-drug treatment. These findings may provide new insights into the biological function of CPNE1 and the development of novel therapeutic strategies for NSCLC.

The CPNE Family and Their Role in Cancers

Lung cancer is the leading cause of cancer-related deaths worldwide. Despite significant advances in cancer research and treatment, the overall prognosis of lung cancer patients remains poor. Therefore, the identification for novel therapeutic targets is critical for the diagnosis and treatment of lung cancer. CPNEs (copines) are a family of membrane-bound proteins that are highly conserved, soluble, ubiquitous, calcium dependent in a variety of eukaryotes. Emerging evidences have also indicated CPNE family members are involved in cancer development and progression as well. However, the expression patterns and clinical roles in cancer have not yet been well understood. In this review, we summarize recent advances concerning CPNE family members and provide insights into new potential mechanism involved in cancer development.

Upregulation of CPNE3 suppresses invasion, migration and proliferation of glioblastoma cells through FAK pathway inactivation

Glioblastoma (GBM) is a deadly brain tumor with a bleak prognosis. In recent years, the copine III (CPNE3) protein was discovered to be associated to metastasis across various types of malignancies. Nevertheless, its function has not been well documented in glioma. This study characterizes CPNE3 expression in GBM along with its impact and underlying molecular mechanism with regards to cellular migration, invasion and proliferation. Immunohistochemistry was used to characterizes CPNE3 expression in the glioma tissues. Then, knockdown of CPNE3 expression was used to analyze the role of CPNE3 in GBM cell viability, migration, invasion. Western blot analysis was performed to measure the protein levels of FAK signaling pathway. We found that GBM tissues had higher CPNE3 expressions as compared to those in normal brain tissues. CPNE3 silencing in GBM cells impaired the migratory, invasive and proliferative abilities of GBM cells that can be attributed to inactivation of the FAK signaling pathway. Collectively, these findings highlight the role of CPNE3 as a new biomarker, offering deeper insights into its carcinogenic role in GBM.

CPNE1 Enhances Colorectal Cancer Cell Growth, Glycolysis, and Drug Resistance Through Regulating the AKT-GLUT1/HK2 Pathway

Introduction

Colorectal cancer (CRC) is a major cause of cancer-related mortality worldwide. Copines-1 (CPNE1) has been shown to be overexpressed in various cancers; however, the role of CPNE1 in CRC remains unknown. Therefore, it is of great importance to elucidate the role of CPNE1 in CRC and its underlying mechanism of action.

Methods

CPNE1 expression in CRC tissues was measured by quantitative real-time PCR and immunohistochemical (IHC) staining. CPNE1 was knocked down (KD) or overexpressed using small inferring RNAs or lentiviral transduction in CRC cells. The proliferation, apoptosis, glycolysis, and mitochondrial respiration of CRC cells were assessed by cell counting kit-8, flow cytometry, and Xfe24 extracellular flux analyzer assays, respectively. The role of CPNE1 in tumor growth and chemoresistance was further confirmed in xenograft and patient-derived tumor xenograft models, respectively.

Results

CPNE1 mRNA and protein were upregulated in CRC tissues. CPNE1 promoted proliferation, inhibited apoptosis, increased mitochondrial respiration, enhanced aerobic glycolysis by activating AKT signaling, upregulated glucose transporter 1 (GLUT1) and hexokinase 2 (HK2), and downregulated the production of cleaved Caspase-3 (c-Caspase 3). CPNE1 also contributed to chemoresistance in CRC cells. CPNE1 KD inhibited tumor growth and increased the sensitivity of tumors to oxaliplatin in vivo.

Conclusion

CPNE1 promotes CRC progression by activating the AKT-GLUT1/HK2 cascade and enhances chemoresistance.

Prevalent intron retention fine-tunes gene expression and contributes to cellular senescence

Intron retention (IR) is the least well‐understood alternative splicing type in animals, and its prevalence and function in physiological and pathological processes have long been underestimated. Cellular senescence contributes to individual aging and age‐related diseases and can also serve as an important cancer prevention mechanism. Dynamic IR events have been observed in senescence models and aged tissues; however, whether and how IR impacts senescence remain unclear. Through analyzing polyA⁺ RNA‐seq data from human replicative senescence models, we found IR was prevalent and dynamically regulated during senescence and IR changes negatively correlated with expression alteration of corresponding genes. We discovered that knocking down (KD) splicing factor U2AF1, which showed higher binding density to retained introns and decreased expression during senescence, led to senescence‐associated phenotypes and global IR changes. Intriguingly, U2AF1‐KD‐induced IR changes also negatively correlated with gene expression. Furthermore, we demonstrated that U2AF1‐mediated IR of specific gene (CPNE1 as an example) contributed to cellular senescence. Decreased expression of U2AF1, higher IR of CPNE1, and reduced expression of CPNE1 were also discovered in dermal fibroblasts with age. We discovered prevalent IR could fine‐tune gene expression and contribute to senescence‐associated phenotypes, largely extending the biological significance of IR.

CPNE1-mediated neuronal differentiation can be inhibited by HAX1 expression in HiB5 cells

We previously demonstrated that CPNE1 induces neuronal differentiation and identified two binding proteins of CPNE1 (14-3-3γ and Jab1) as potential regulators of CPNE1-mediated neuronal differentiation in hippocampal progenitor cells. To better understand the cellular processes in which CPNE1 participates in neuronal differentiation, we here carried out a yeast two-hybrid screening to find another CPNE1 binding protein. Among the identified proteins, HCLS1-related protein X-1 (HAX1) directly interacts with CPNE1. Immunostaining experiments showed that a fraction of CPNE1 and HAX1 co-localized in the cytosol, particularly in the plasma membrane. In addition, the physical interaction as well as the specific binding regions between CPNE1 and HAX1 were confirmed in vitro and in vivo. Moreover, AKT phosphorylation, Tuj1 (neuronal marker protein) expression, and neurite outgrowth are all reduced in CPNE1/HAX1 overexpressing cells compared to CPNE1 only overexpressing HiB5 cells. Conversely, the HAX1 mutant that does not bind to CPNE1 was unable to inhibit the CPNE1-mediated neuronal differentiation. Together these results indicate that HAX1 is a binding partner of CPNE1 and CPNE1-mediated neuronal differentiation is negatively affected through the binding of HAX1, especially its N-terminal region, with CPNE1.

Role of the Sec22b-E-Syt complex in neurite growth and ramification

Axons and dendrites are long and often ramified neurites that need particularly intense plasma membrane (PM) expansion during the development of the nervous system. Neurite growth depends on non-fusogenic Sec22b-Stx1 SNARE complexes at endoplasmic reticulum (ER)-PM contacts. Here, we show that Sec22b interacts with members of the extended synaptotagmin (E-Syt) family of ER lipid transfer proteins (LTPs), and this interaction depends on the longin domain of Sec22b. Overexpression of E-Syts stabilizes Sec22b-Stx1 association, whereas silencing of E-Syts has the opposite effect. Overexpression of wild-type E-Syt2, but not mutants unable to transfer lipids or attach to the ER, increase the formation of axonal filopodia and ramification of neurites in developing neurons. This effect is inhibited by a clostridial neurotoxin cleaving Stx1, and expression of the Sec22b longin domain and a Sec22b mutant with an extended linker between the SNARE and transmembrane domains. We conclude that Sec22b-Stx1 ER-PM contact sites contribute to PM expansion by interacting with LTPs, such as E-Syts.This article has an associated First Person interview with the first author of the paper.

Quantifying Serum Derived Differential Expressed and Low Molecular Weight Protein in Breast Cancer Patients

Background:

Searching the biomarker from complex heterogeneous material for early detection of disease is a challenging task in the field of biomedical sciences.

Objective:

The study has been arranged to explore the proteomics serum derived profiling of the differential expressed and low molecular weight protein in breast cancer patient.

Methods:

Quantitative proteome was analyzed using the Nano LC/Mass and Bioinformatics tool.

Results:

This quantification yields 239 total protein constituting 29% of differentially expressed protein, with 82% downregulated differential protein and 18% up-regulated differential protein. While 12% of total protein were found to be cancer inducing proteins. Gene Ontology (GO) described that the altered proteins with 0-60 kDa mass in nucleus, cytosol, ER, and mitochondria were abundant that chiefly controlled the RNA, DNA, ATP, Ca ion and receptor bindings.

Conclusion:

The study demonstrate that the organelle specific, low molecular weighted proteins are significantly important biomarker. That act as strong agents in the prognosis and diagnosis of breast cancer at early stage.

CPNE1 predicts poor prognosis and promotes tumorigenesis and radioresistance via the AKT singling pathway in triple-negative breast cancer

Elevated expression of Copine 1 (CPNE1) has been observed in multiple cancers; however, the underlying mechanisms by which it affects cancer cells are unclear. We aimed to study the effect of CPNE1 on the tumorigenesis and radioresistance of triple‐negative breast cancer (TNBC). Quantitative real‐time polymerase chain reaction was used to detect the expression of CPNE1 in TNBC tissues and cell lines. Western blot, immunohistochemistry, and immunofluorescence were used to investigate the levels of CPNE1, p‐AKT, AKT, cleaved caspase‐3, cleaved PARP1, and γ‐H2AX. Cell viability and apoptosis were measured by CCK‐8 and flow cytometry, respectively. CPNE1 was overexpressed in TNBC tissues and cell lines and was associated with tumor size, distant metastases, and survival rates of patients with TNBC. Moreover, function study shows that CPNE1 promoted cell viability and inhibited cell apoptosis in vitro and inhibited the radiosensitivity of TNBC. Importantly, inactivation of AKT signaling inhibited the tumorigenesis and radioresistance mediated by CPNE1 in TNBC cells. In vivo xenograft study also shows that CPNE1 knockdown inhibited tumor growth and promoted cell apoptosis. Overall, our findings suggest that CPNE1 promotes tumorigenesis and radioresistance in TNBC by regulating AKT activation and targeted CPNE1 expression may be a strategy to sensitize TNBC cells toward radiation therapy.

MiR-195-5p is a Potential Factor Responsible for CPNE1 Differential Expression between Subtypes of Non-Small Cell Lung Cancer

Purpose: Lung cancer is the most common malignancy with poor 5-year survival among men and women. Previous studies have shown that CPNE1 is up-regulated in non-small cell lung cancer (NSCLC). However, whether and how CPNE1 expression varies between different subtypes of NSCLC remains less understood.

Methods: Bioinformatical analysis and GSE19188 were selected to confirm CPNE1 expression in different subtypes of NSCLC. Four microRNA prediction websites and GSE53883, GSE43000 were used to evaluate the possible targeting microRNAs. Kaplan-Meier survival curves were drawn based on Tumor Lung Bild -114 dataset using R2, UCSC Xena browser or linkedomics platform. Furthermore, we verified our prediction via qRT-PCR, and western blot and luciferase reporter assays.

Results: we demonstrated that higher CPNE1 expression was associated with poorer survival in NSCLC patients. Moreover, among the different subtypes, patients with squamous cell lung cancer (SCC) exhibited higher level of CPNE1 expression, as well as substantially poorer survival. MiR-195-5p was down-regulated in NSCLC tissues. Interestingly, SCC patients showed lower miR-195-5p expression compared to patients with lung adenocarcinoma (ADC). In addition, functional assays proved that miR-195-5p overexpression inhibited the proliferation, migration, and invasion of NSCLC-derived cells by directly targeting CPNE1. Pathway analysis showed decreased expression of p-AKT, p-Erk, and Snail after transfection with miR-195-5p mimics in both lung adenocarcinoma and squamous cell lines.

Conclusion: Our findings suggested that miR-195-5p regulation contributed to the differential expression of CPNE1 in NSCLC subtypes.

Expression quantitative trait loci-derived scores and white matter microstructure in UK Biobank: a novel approach to integrating genetics and neuroimaging

Expression quantitative trait loci (eQTL) are genetic variants associated with gene expression. Using genome-wide genotype data, it is now possible to impute gene expression using eQTL mapping efforts. This approach can be used to analyse previously unexplored relationships between gene expression and heritable in vivo measures of human brain structural connectivity. Using large-scale eQTL mapping studies, we computed 6457 gene expression scores (eQTL scores) using genome-wide genotype data in UK Biobank, where each score represents a genetic proxy measure of gene expression. These scores were then tested for associations with two diffusion tensor imaging measures, fractional anisotropy (N_FA = 14,518) and mean diffusivity (N_MD = 14,485), representing white matter structural integrity. We found FDR-corrected significant associations between 8 eQTL scores and structural connectivity phenotypes, including global and regional measures (β_absolute FA = 0.0339-0.0453; MD = 0.0308-0.0381) and individual tracts (β_absolute FA = 0.0320-0.0561; MD = 0.0295-0.0480). The loci within these eQTL scores have been reported to regulate expression of genes involved in various brain-related processes and disorders, such as neurite outgrowth and Parkinson's disease (DCAKD, SLC35A4, SEC14L4, SRA1, NMT1, CPNE1, PLEKHM1, UBE3C). Our findings indicate that eQTL scores are associated with measures of in vivo brain connectivity and provide novel information not previously found by conventional genome-wide association studies. Although the role of expression of these genes regarding white matter microstructural integrity is not yet clear, these results suggest it may be possible, in future, to map potential trait- and disease-associated eQTL to in vivo brain connectivity and better understand the mechanisms of psychiatric disorders and brain traits, and their associated imaging findings.

High expression of Copine 1 promotes cell growth and metastasis in human lung adenocarcinoma

Despite advances in diagnosis and treatment, the survival of non-small cell lung cancer (NSCLC) patients is poor. Further understanding of the disease mechanism and treatment strategies is required. Copines are a family of calcium-dependent phospholipid-binding proteins that are evolutionally conserved in various eukaryotic organisms and protists. Copine 1, encoded by CPNE1, is a soluble membrane-binding protein, which includes two tandem C2 domains at the N-terminus and an A domain at the C-terminus. A previous study reported that Copine 1 binds with various intracellular proteins via its A domain and C omain. However, the role of CPNE1 in lung cancer remains unclear. In the presented study, CPNE1 expression level was demonstrated to be positively associated with the stage (P=0.002) and significantly associated with lymph node status (P=0.011) and distant metastasis (P=0.042). Furthermore, the function of CPNE1 in regulation of cell growth, migration and invasion was investigated, and it was demonstrated that knockdown of CPNE1 inhibits the cell cycle in NSCLC cells. Collectively, these data suggest that CPNE1 is an oncogene in NSCLC and serves an important role in tumorigenesis of NSCLC progression.

CPNE1 is a target of miR-335-5p and plays an important role in the pathogenesis of non-small cell lung cancer

Background

Despite advances in diagnosis and treatment, the survival of non-small cell lung cancer (NSCLC) patients remains poor. There is therefore a strong need to identify potential molecular targets for the treatment of NSCLC. In the present study, we investigated the function of CPNE1 in the regulation of cell growth, migration and invasion.

Methods

Quantitative real-time PCR (qRT-PCR) was used to detect the expression of CPNE1 and miR-335-5p. Western blot and immunohistochemical assays were used to investigate the levels of CPNE1 and other proteins. Flow cytometry was used to determine cell cycle stage and apoptosis. CCK-8 and clonogenic assays were used to investigate cell proliferation. Wound healing, migration and invasion assays were used to investigate the motility of cells. A lung carcinoma xenograft mouse model was used to investigate the in vivo effects of CPNE1 overexpression.

Results

We observed that knockdown of CPNE1 and increased expression of miR-335-5p inhibits cell proliferation and motility in NSCLC cells, and found that CPNE1 was a target of miR-335-5p. In addition, our data indicated that CPNE1 inhibition could improve the clinical effects of EGFR-tyrosine kinase inhibitors.

Conclusions

The present results indicate that CPNE1 may be a promising molecular target in the treatment of NSCLC.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0811-6) contains supplementary material, which is available to authorized users.

Transcriptional Analysis of Blood Lymphocytes and Skin Fibroblasts, Keratinocytes, and Endothelial Cells as a Potential Biomarker for Alzheimer's Disease

Alzheimer's disease (AD) is a devastating and progressive form of dementia that is typically associated with a build-up of amyloid-β plaques and hyperphosphorylated and misfolded tau protein in the brain. Presently, there is no single test that confirms AD; therefore, a definitive diagnosis is only made after a comprehensive medical evaluation, which includes medical history, cognitive tests, and a neurological examination and/or brain imaging. Additionally, the protracted prodromal phase of the disease makes selection of control subjects for clinical trials challenging. In this study we have utilized a gene-expression array to screen blood and skin punch biopsy (fibroblasts, keratinocytes, and endothelial cells) for transcriptional differences that may lead to a greater understanding of AD as well as identify potential biomarkers. Our analysis identified 129 differentially expressed genes from blood of dementia cases when compared to healthy individuals, and four differentially expressed punch biopsy genes between AD subjects and controls. Additionally, we identified a set of genes in both tissue compartments that showed transcriptional variation in AD but were largely stable in controls. The translational products of these variable genes are involved in the maintenance of the Golgi structure, regulation of lipid metabolism, DNA repair, and chromatin remodeling. Our analysis potentially identifies specific genes in both tissue compartments that may ultimately lead to useful biomarkers and may provide new insight into the pathophysiology of AD.

CPNE1 Is a Useful Prognostic Marker and Is Associated with TNF Receptor-Associated Factor 2 (TRAF2) Expression in Prostate Cancer

Background

CPNE1 plays a vital role in regulating cell differentiation. The clinical and biological values of CPNE1 in prostate cancer are still unclear. The aim of this study was to investigate the clinicopathological value of CPNE1 and the association of CPNE1 with TRAF2 expression in patients with prostate cancer.

Material/Methods

CPNE1 expression in prostate cancer was analyzed using Gene Expression Omnibus (GEO) databases. The Cancer Genome Atlas (TCGA) dataset was used to investigate the association of CPNE1 expression with TRAF2 expression in prostate cancer. The association of CPNE1 expression with recurrence-free survival in patients was also analyzed using the TCGA dataset. Immunohistochemistry assay was performed to examine CPNE1 expression in 65 normal prostate samples and 114 prostate cancer samples. The recurrence-free survival in patients was evaluated using Kaplan-Meier curves and log-rank test. In addition, multivariate and univariate analyses of prognostic factors were investigated by Cox regression. The effect of CPNE1 on TRAF2 expression was explored in human prostate cancer DU-145 cells.

Results

Our results showed that expression level of CPNE1 is higher in prostate cancer than in normal prostate tissues (P=0.006). In the GSE35988 dataset, CPNE1 expression was found to be upregulated in castration-resistant prostate cancer compared with non-castration-resistant prostate cancer (P<0.001). Furthermore, we found that CPNE1 high expression was significantly related to tumor stage, Gleason score, and poorer biochemical recurrence-free survival in prostate cancer patients. Co-expression analysis of TCGA data showed that CPNE1 is significantly associated with TRAF2 expression. CPNE1 overexpression can upregulate TRAF2 expression in prostate cancer DU-145 cells as determined by Western blotting and immunofluorescence assays.

Conclusions

Overall, our findings suggest that CPNE1 is a valuable prognostic marker for evaluating recurrence-free survival and is positively related to TRAF2 expression in prostate cancer.

Copine1 regulates neural stem cell functions during brain development

Copine 1 (CPNE1) is a well-known phospholipid binding protein in plasma membrane of various cell types. In brain cells, CPNE1 is closely associated with AKT signaling pathway, which is important for neural stem cell (NSC) functions during brain development. Here, we investigated the role of CPNE1 in the regulation of brain NSC functions during brain development and determined its underlying mechanism. In this study, abundant expression of CPNE1 was observed in neural lineage cells including NSCs and immature neurons in human. With mouse brain tissues in various developmental stages, we found that CPNE1 expression was higher at early embryonic stages compared to postnatal and adult stages. To model developing brain in vitro, we used primary NSCs derived from mouse embryonic hippocampus. Our in vitro study shows decreased proliferation and multi-lineage differentiation potential in CPNE1 deficient NSCs. Finally, we found that the deficiency of CPNE1 downregulated mTOR signaling in embryonic NSCs. These data demonstrate that CPNE1 plays a key role in the regulation of NSC functions through the activation of AKT-mTOR signaling pathway during brain development.

14-3-3γ regulates Copine1-mediated neuronal differentiation in HiB5 hippocampal progenitor cells

Copine1 (CPNE1), known as a calcium-dependent membrane-binding protein, has tandem C2 domains and an A domain. We previously demonstrated that CPNE1 directly induces neuronal differentiation via Protein kinase B (AKT) phosphorylation in the hippocampal progenitor cell line, HiB5. To better understand its cellular function, we carried out a yeast two-hybrid screening to find CPNE1 binding partners. Among the identified proteins, 14-3-3γ appears to directly interact with CPNE1. Between CPNE1 and 14-3-3γ, the physical interaction as well as the specific binding regions of CPNE1 was confirmed in vitro and in vivo. Furthermore, among the seven 14-3-3 isotypes, only 14-3-3γ directly interacts with CPNE1. Our results also demonstrate that AKT phosphorylation, neurite outgrowth and expression of the neuronal marker protein are increased when 14-3-3γ is overexpressed in CPNE1 high expressed HiB5 cells. Furthermore, the neighboring Ser54 amino acids residue of C2A domain in CPNE1 has an important role in binding with 14-3-3γ, and in differentiation-related function of CPNE1. Moreover, mutation of Ser54 amino acids residue in CPNE1 effectively decreased association with 14-3-3γ and neuronal differentiation of HiB5 cells. Collectively, our findings indicate that 14-3-3γ regulates the differentiation ability of CPNE1 through the binding with C2A domain of CPNE1 in HiB5 cells.