CPNE3 promotes migration and invasion in non-small cell lung cancer by interacting with RACK1 via FAK signaling activation

YAP1-CPNE3 positive feedback pathway promotes gastric cancer cell progression

Hippo-Yes-associated protein 1 (YAP1) plays an important role in gastric cancer (GC) progression; however, its regulatory network remains unclear. In this study, we identified Copine III (CPNE3) was identified as a novel direct target gene regulated by the YAP1/TEADs transcription factor complex. The downregulation of CPNE3 inhibited proliferation and invasion, and increased the chemosensitivity of GC cells, whereas the overexpression of CPNE3 had the opposite biological effects. Mechanistically, CPNE3 binds to the YAP1 protein in the cytoplasm, inhibiting YAP1 ubiquitination and degradation mediated by the E3 ubiquitination ligase β-transducin repeat-containing protein (β-TRCP). Thereby activating the transcription of YAP1 downstream target genes, which creates a positive feedback cycle to facilitate GC progression. Immunohistochemical analysis demonstrated significant upregulation of CPNE3 in GC tissues. Survival and Cox regression analyses indicated that high CPNE3 expression was an independent prognostic marker for GC. This study elucidated the pivotal involvement of an aberrantly activated CPNE3/YAP1 positive feedback loop in the malignant progression of GC, thereby uncovering novel prognostic factors and therapeutic targets in GC.

[High expression of CPNE3 correlates with poor long-term prognosis of gastric cancer by inhibiting cell apoptosis via activating PI3K/AKT signaling]

OBJECTIVE

To explore the correlation of CPNE3 expression with long-term prognosis of patients with gastric cancer (GC) and the possible mechanism.

METHODS

We retrospectively collected the data of 104 GC patients undergoing radical surgery in our hospital from February, 2013 to October, 2017. TCGA database and immunohistochemistry were used to analyze CPNE3 expression level in GC tissues and its effects on tumor progression and long-term prognosis of the patients. GO analysis was performed to predict the biological role of CPNE3 in GC. We also conducted cell experiments with MGC803 cells and observed the effects of CPNE3 knockdown, CPNE3 overexpression and LY294002 (a PI3K/AKT inhibitor) treatment on cell apoptosis and cellular expressions of apoptotic proteins using flow cytometry and Western blotting.

RESULTS

TCGA analysis and immunohistochemistry both showed high expressions of CPNE3 in GC (P < 0.05). The patients with high CPNE3 expressions had a reduced 5-year survival (P < 0.01), and a high CPNE3 expression, CEA level≥5 μg/L, CA19-9 level ≥37 kU/L, T3-T4 stage, and N2-N3 stage were all independent risk factors for a lowered 5-year survival rate after surgery. The sensitivity and specificity of CPNE3 for predicting 5-year mortality was 79.59% and 74.55%, respectively (P < 0.05). GO analysis predicted that CPNE3 negatively regulated GC cell apoptosis. In MGC803 cells, CPNE3 knockdown significantly increased cell apoptosis, enhanced Bax and Cleaved Caspase-3 expressions and decreased Bcl-2 expression, while CPNE3 overexpression produced the opposite results (P < 0.05). The cellular expressions of p-PI3K and p-AKT were significantly decreased following CPNE3 knockdown and increased following CPNE3 overexpression (P < 0.05). Treatment with LY294002 obviously attenuated the inhibitory effect of CPNE3 overexpression on apoptosis of MGC803 cells (P < 0.05).

CONCLUSION

CPNE3 is highly expressed in GC tissues and affects the long-term prognosis of the patients possibly by inhibiting GC cell apoptosis through activation of PI3K/AKT signaling.

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.

CPNE3 interaction with RACK1 protects against myocardial ischemia/reperfusion injury

Copine 3 (CPNE3) and receptor for activated C kinase 1 (RACK1) have been determined to be risk factors for patients with acute myocardial ischemia/reperfusion (I/R). The present study aimed to evaluate the role of CPNE3 and its interaction with RACK1 in myocardial (I/R) injury. Reverse transcription-quantitative PCR (RT-qPCR) and western blotting were performed to detect CPNE3 and RACK1 expression levels in H9c2 cells before and after the transfection of CPNE3 overexpression plasmid or small interfering RNA-RACK1. Cell viability was detected using a Cell Counting Kit-8 assay, and immunoprecipitation assays were performed to determine the interaction between CPNE3 and RACK1. A commercial kit was used to examine lactate dehydrogenase (LDH) levels. The expression levels of inflammatory cytokines were detected via RT-qPCR and western blotting. Cell apoptosis was assessed via TUNEL staining and western blotting. The results demonstrated that the expression levels of CPNE3 and RACK1 were decreased in hypoxia/reoxygenation (H/R)-induced H9c2 cardiomyocytes, which was consistent with the expression levels observed in the myocardial I/R injury rat model. It was found that CPNE3 overexpression upregulated RACK1 expression, increased cell viability and suppressed the release of LDH in H/R-induced H9c2 cells. Furthermore, CPNE3 overexpression inhibited the release of inflammatory cytokines and decreased cell apoptosis in H/R-induced cardiomyocytes by activating RACK1 expression. The present study suggested that CPNE3 served an important role in preventing I/R injury by interacting with RACK1, providing novel insight into the prevention of myocardial I/R injury, as well as the treatment and care of patients with myocardial I/R.

The regulation of CPNE1 ubiquitination by the NEDD4L is involved in the pathogenesis of non-small cell lung cancer

Our previous studies revealed that oncogene CPNE1 is positively correlated with the occurrence, TNM stage, lymph node metastasis, and distant metastasis of non-small-cell lung cancer (NSCLC), and it could be regulated by micro RNAs. But no direct role of post-translational modification of CPNE1 in NSCLC has been reported. This study confirms that CPNE1 is degraded by two pathways: the ubiquitin-proteasome pathway and the autophagy-lysosome pathway. CPNE1 binds with the ubiquitin molecule via its K157 residue. Moreover, we determined that the ubiquitin ligase NEDD4L can mediate the ubiquitination of CPNE1 and promote its degradation. In addition, we find that NEDD4L knockdown promotes the proliferation and metastasis of NSCLC cells by regulating CPNE1 in vitro and vivo. This study aims to further investigate the mechanism of CPNE1 ubiquitination in the occurrence and development of NSCLC and provide a new potential target for NSCLC treatment.

Copine 3 "CPNE3" is a novel regulator for insulin secretion and glucose uptake in pancreatic β-cells

Copine 3 (CPNE3) is a calcium-dependent phospholipid-binding protein that has been found to play an essential role in cancer progression and stages. However, its role in pancreatic β-cell function has not been investigated. Therefore, we performed a serial of bioinformatics and functional experiments to explore the potential role of Cpne3 on insulin secretion and β-cell function in human islets and INS-1 (832/13) cells. RNA sequencing and microarray data revealed that CPNE3 is highly expressed in human islets compared to other CPNE genes. In addition, expression of CPNE3 was inversely correlated with HbA1c and reduced in human islets from hyperglycemic donors. Silencing of Cpne3 in INS-1 cells impaired glucose-stimulated insulin secretion (GSIS), insulin content and glucose uptake efficiency without affecting cell viability or inducing apoptosis. Moreover, mRNA and protein expression of the key regulators in glucose sensing and insulin secretion (Insulin, GLUT2, NeuroD1, and INSR) were downregulated in Cpne3-silenced cells. Taken together, data from the present study provides a new understanding of the role of CPNE3 in maintaining normal β-cell function, which might contribute to developing a novel target for future management of type 2 diabetes therapy.

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.

Upregulated CD58 is associated with clinicopathological characteristics and poor prognosis of patients with pancreatic ductal adenocarcinoma

Background

CD58 has been demonstrated to be abnormally expressed in multiple hematopoietic malignancies and solid tumors and plays an essential role in tumorigenesis and progression; however, its clinical significance and prognostic value in pancreatic ductal adenocarcinoma (PDAC) remain unknown.

Methods

Based on diverse online public databases and 81 PDAC samples of tissue microarray-based immunohistochemistry (IHC), we evaluated CD58 expression in PDAC patients and analyzed its association with clinicopathological characteristics, clinical outcomes, and infiltration of immune cells in PDAC. Furthermore, the correlation between CD58 and the cancer stem cell (CSC)-related, epithelial–mesenchymal transition (EMT)-related, and immune-related markers were detected. Besides, the functional enrichment analysis and related pathways were analyzed and visualized.

Results

CD58 expression was elevated in pancreatitis and PDAC tissues than normal pancreas or adjacent nontumor tissues. The positive cases of CD58 (e.g. more than 50% positive cells) in PDAC account for 95.06% (77/81). Upregulated CD58 in cancer tissues was associated with worse histological grade, larger tumor size, and poorer overall survival and disease-free survival in PDAC patients. Furthermore, Cox multivariate regression analysis revealed that CD58 was an independent prognostic factor in PDAC. CD58 expression was correlated with infiltrations of neutrophils, CD8⁺ T cells, and dendritic cells (DCs). In addition, correlation gene analysis indicated that CD58 expression was strongly correlated with immune-related, EMT-related, and CSC-related markers. Functional enrichment analysis and KEGG pathway manifested that CD58 might be involved in PDAC initiation and progression.

Conclusions

CD58 expression is upregulated in PDAC tissues and its high expression is notably related to poor survival of PDAC. Therefore, CD58 may serve as a novel and effective marker for predicting the prognosis of PDAC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02037-0.

High expression of CPNE5 and CPNE9 predicts positive prognosis in multiple myeloma

BACKGROUND

CPNEs are significant biomarkers which can affect the progression and prognosis of various tumor diseases. However, the prognosis role of CPNEs in multiple myeloma (MM) is still unclear.

OBJECTIVES

To investigate the prognosis role of CPNEs in MM.

METHODS

Seven hundred and thirty-five samples from two independent data sets were involved to analyze the clinical and molecular characteristics, and prognosis role of the expression of CPNE1-9 in MM.

RESULTS

MM patients with higher expressions of CPNE5 and CPNE9 had longer event-free survival (EFS) and overall survival (OS) compared with CPNE5low and CPNE9low expression groups (EFS: P= 0.0054, 0.0065; OS: P= 0.015, 0.016, respectively). Multivariate regression analysis showed that CPNE5 was an independent favorable predictor for EFS and OS (EFS: P= 0.005; OS: P= 0.006), and CPNE9 was an independent positive indicator for EFS (P= 0.002). Moreover, the survival probability and the cumulative event of EFS and OS in CPNE5highCPNE9high group were significantly longer than other groups.

CONCLUSIONS

High expressions of CPNE5 and CPNE9 might be used as positive indicators for MM, and their combination was a better predictor for the survival of MM patients.

Overexpression of RACK1 Predicts Poor Prognosis in Melanoma

Melanoma is a highly malignant skin cancer with limited treatment options, the mechanism of the occurrence and development of melanoma is still unclear till now. Receptor for activated C kinase 1 (RACK1) is a scaffolding protein that mediates multiple signaling pathways; it interconnects distinct signaling pathways to control essential cellular processes. RACK1 was reported as an oncogene in human tumorigenesis, but little is known about its role in melanoma. This study aimed to investigate the expression of RACK1 in patients with melanoma and to reveal its possible functions in melanoma cells. The expression profiles of RACK1 detected in tumor tissues from melanoma patients showed that RACK1 was higher in tumor tissues, and its expression level was well associated with the clinical progression of melanoma (TNM stage, P=0.009). Furthermore, RNA interfering (RNAi) knockdown of RACK1 could efficiently suppress the proliferation, migration and invasion of A375 and A875 cells and promote their apoptosis. Taken together, these results suggest that RACK1 may be a poor prognostic factor in human melanoma, and it may be a new therapeutic target for melanoma treatment.