CAS proteins in normal and pathological cell growth control

Mechanotransduction and the extracellular matrix: Key drivers of lung pathologies and drug responsiveness

The lung is a biomechanically active organ, with multiscale mechanical forces impacting the organ, tissue and cellular responses within this microenvironment. In chronic lung diseases, such as chronic obstructive pulmonary disease, pulmonary fibrosis and others, the structure of the lung is drastically altered impeding gas exchange. These changes are, in part, reflected in alterations in the composition, amount and organization of the extracellular matrix within the different lung compartments. The transmission of mechanical forces within lung tissue are broadcast by this complex mix of extracellular matrix components, in particular the collagens, elastin and proteoglycans and the crosslinking of these components. At both a macro and a micro level, the mechanical properties of the microenvironment have a key regulatory role in ascertaining cellular responses and the function of the lung. Cells adhere to, and receive signals from, the extracellular matrix through a number of different surface receptors and complexes which are important for mechanotransduction. This review summarizes the multiscale mechanics in the lung and how the mechanical environment changes in lung disease and aging. We then examine the role of mechanotransduction in driving cell signaling events in lung diseases and finish with a future perspective of the need to consider how such forces may impact pharmacological responsiveness in lung diseases.

Use of phosphotyrosine-containing peptides to target SH2 domains: Antagonist peptides of the Crk/CrkL-p130Cas axis

Protein-protein interactions between SH2 domains and segments of proteins that include a post-translationally phosphorylated tyrosine residue (pY) underpin numerous signal transduction cascades that allow cells to respond to their environment. Dysregulation of the writing, erasing, and reading of these posttranslational modifications is a hallmark of human disease, notably cancer. Elucidating the precise role of the SH2 domain-containing adaptor proteins Crk and CrkL in tumor cell migration and invasion is challenging because there are no specific and potent antagonists available. Crk and CrkL SH2s interact with a region of the docking protein p130Cas containing 15 potential pY-containing tetrapeptide motifs. This chapter summarizes recent efforts toward peptide antagonists for this Crk/CrkL-p130Cas interaction. We describe our protocol for recombinant expression and purification of Crk and CrkL SH2s for functional assays and our procedure to determine the consensus binding motif from the p130Cas sequence. To develop a more potent antagonist, we employ methods often associated with structure-based drug design. Computational docking using Rosetta FlexPepDock, which accounts for peptides having a greater number of conformational degrees of freedom than small organic molecules that typically constitute libraries, provides quantitative docking metrics to prioritize candidate peptides for experimental testing. A battery of biophysical assays, including fluorescence polarization, differential scanning fluorimetry and saturation transfer difference nuclear magnetic resonance spectroscopy, were employed to assess the candidates. In parallel, GST pulldown competition assays characterized protein-protein binding in vitro. Taken together, our methodology yields peptide antagonists of the Crk/CrkL-p130Cas axis that will be used to validate targets, assess druggability, foster in vitro assay development, and potentially serve as lead compounds for therapeutic intervention.

EGFR targeting PhosTACs as a dual inhibitory approach reveals differential downstream signaling

We recently developed a heterobifunctional approach [phosphorylation targeting chimeras (PhosTACs)] to achieve the targeted protein dephosphorylation (TPDephos). Here, we envisioned combining the inhibitory effects of receptor tyrosine kinase inhibitors (RTKIs) and the active dephosphorylation by phosphatases to achieve dual inhibition of kinases. We report an example of tyrosine phosphatase-based TPDephos and the effective epidermal growth factor receptor (EGFR) tyrosine dephosphorylation. We also used phosphoproteomic approaches to study the signaling transductions affected by PhosTAC-related molecules at the proteome-wide level. This work demonstrated the differential signaling pathways inhibited by PhosTAC compared with the TKI, gefitinib. Moreover, a covalent PhosTAC selective for mutated EGFR was developed and showed its inhibitory potential for dysregulated EGFR. Last, EGFR PhosTACs, consistent with EGFR dephosphorylation profiles, induced apoptosis and inhibited cancer cell viability during prolonged PhosTAC treatment. PhosTACs showcased their potential of modulating RTKs activity, expanding the scope of bifunctional molecule utility.

An adhesion signaling axis involving Dystroglycan, β1-Integrin, and Cas adaptor proteins regulates the establishment of the cortical glial scaffold

The mature mammalian cortex is composed of 6 architecturally and functionally distinct layers. Two key steps in the assembly of this layered structure are the initial establishment of the glial scaffold and the subsequent migration of postmitotic neurons to their final position. These processes involve the precise and timely regulation of adhesion and detachment of neural cells from their substrates. Although much is known about the roles of adhesive substrates during neuronal migration and the formation of the glial scaffold, less is understood about how these signals are interpreted and integrated within these neural cells. Here, we provide in vivo evidence that Cas proteins, a family of cytoplasmic adaptors, serve a functional and redundant role during cortical lamination. Cas triple conditional knock-out (Cas TcKO) mice display severe cortical phenotypes that feature cobblestone malformations. Molecular epistasis and genetic experiments suggest that Cas proteins act downstream of transmembrane Dystroglycan and β1-Integrin in a radial glial cell-autonomous manner. Overall, these data establish a new and essential role for Cas adaptor proteins during the formation of cortical circuits and reveal a signaling axis controlling cortical scaffold formation.

Creatine kinase brain-type regulates BCAR1 phosphorylation to facilitate DNA damage repair

Creatine kinase (CK) is an essential metabolic enzyme mediating creatine/phosphocreatine interconversion and shuttle to replenish ATP for energy needs. Ablation of CK causes a deficiency in energy supply that eventually results in reduced muscle burst activity and neurological disorders in mice. Besides the well-established role of CK in energy-buffering, the mechanism underlying the non-metabolic function of CK is poorly understood. Here we demonstrate that creatine kinase brain-type (CKB) may function as a protein kinase to regulate BCAR1 Y327 phosphorylation that enhances the association between BCAR1 and RBBP4. Then the complex of BCAR1 and RPPB4 binds to the promoter region of DNA damage repair gene RAD51 and activates its transcription by modulating histone H4K16 acetylation to ultimately promote DNA damage repair. These findings reveal the possible role of CKB independently of its metabolic function and depict the potential pathway of CKB-BCAR1-RBBP4 operating in DNA damage repair.

Prognostic biomarkers and molecular pathways mediating Helicobacter pylori–induced gastric cancer: a network-biology approach

Cancer of the stomach is the second most frequent cancer-related death worldwide. The survival rate of patients with gastric cancer (GC) remains fragile. There is a requirement to discover biomarkers for prognosis approaches. Helicobacter pylori in the stomach is closely associated with the progression of GC. We identified the genes associated with poor/favorable prognosis in H. pylori–induced GC. Multivariate statistical analysis was applied on the Gene Expression Omnibus (GEO) dataset GSE54397 to identify differentially expressed miRNAs (DEMs) in gastric tissues with H. pylori–induced cancer compared with the H. pylori–positive with non-cancerous tissue. A protein interaction map (PIM) was built and subjected to DEMs targets. The enriched pathways and biological processes within the PIM were identified based on substantial clusters. Thereafter, the most critical genes in the PIM were illustrated, and their prognostic impact in GC was investigated. Considering p-value less than 0.01 and |Log2 fold change| as >1, five microRNAs demonstrated significant changes among the two groups. Gene functional analysis revealed that the ubiquitination system, neddylation pathway, and ciliary process are primarily involved in H. pylori–induced GC. Survival analysis illustrated that the overexpression of DOCK4, GNAS, CTGF, TGF-b1, ESR1, SELE, TIMP3, SMARCE1, and TXNIP was associated with poor prognosis, while increased MRPS5 expression was related to a favorable prognosis in GC patients. DOCK4, GNAS, CTGF, TGF-b1, ESR1, SELE, TIMP3, SMARCE1, TXNIP, and MRPS5 may be considered prognostic biomarkers for H. pylori–induced GC. However, experimental validation is necessary in the future.

p130Cas is required for androgen-dependent postnatal development regulation of submandibular glands

Salivary glands develop through epithelial-mesenchymal interactions and are formed through repeated branching. The Crk-associated substrate protein (p130Cas) serves as an adapter that forms a complex with various proteins via integrin and growth factor signaling, with important regulatory roles in several essential cellular processes. We found that p130Cas is expressed in ductal epithelial cells of the submandibular gland (SMG). We generated epithelial tissue-specific p130Cas-deficient (p130Cas^Δepi-) mice and aimed to investigate the physiological role of p130Cas in the postnatal development of salivary glands. Histological analysis showed immature development of granular convoluted tubules (GCT) of the SMG in male p130Cas^Δepi- mice. Immunofluorescence staining showed that nuclear-localized androgen receptors (AR) were specifically decreased in GCT cells in p130Cas^Δepi- mice. Furthermore, epidermal growth factor-positive secretory granules contained in GCT cells were significantly reduced in p130Cas^Δepi- mice with downregulated AR signaling. GCTs lacking p130Cas showed reduced numbers and size of secretory granules, disrupted subcellular localization of the cis-Golgi matrix protein GM130, and sparse endoplasmic reticulum membranes in GCT cells. These results suggest that p130Cas plays a crucial role in androgen-dependent GCT development accompanied with ER-Golgi network formation in SMG by regulating the AR signaling.

Involvement of the PRL-PAK1 Pathway in Cancer Cell Migration

Prolactin (PRL) is a polypeptide hormone synthesized in the lactotrophs of the adenohypophysis and in extrahypophyseal glands (such as the prostate and breasts) where it promotes their development. PRL is also involved in cancer development in these glands. It has been shown to stimulate cancer cell migration, suggesting its possible involvement in metastasis, in which cell migration plays an essential role. However, the role of PRL in cell migration is still unclear. Moreover, the intracellular mechanisms activated by PRL to carry out cell migration are less well understood. PRL exerts its effects via the PRL receptor (PRLR), which leads intracellularly to phosphorylation of Janus protein kinase 2 (JAK2), which in turn phosphorylates p21-activated protein kinase (PAK1), leading to an increase in cell migration. Although several studies have described the involvement of the PRL-PAK1 pathway in breast cancer cell migration, the molecular mechanisms have not been fully elucidated and there is no integration of these into signaling pathways. This study was conducted based on literature search of review articles and original research in the PubMed database, using the following keywords: PRL, cell migration, PRL and cell migration, PAK1 and signaling pathways. The aim of this review article was to describe the major signaling pathways controlled by PRL-PAK1 and propose a comprehensive model of the signaling pathways associated with PRL-PAK1.

Gli1 promotes the phenotypic transformation of valve interstitial cells through Hedgehog pathway activation exacerbating calcific aortic valve disease

Calcific aortic valve disease (CAVD) is the most prevalent human valve disease worldwide. Multiple factors induce "irreversible" pathological changes in the aortic valve leaflets, resulting in changes in cardiac hemodynamics, eventually leading to heart failure. However, no effective pharmaceutical interventions have been found and prosthetic valve replacement is the only curative approach. Glioma-associated oncogene 1 (Gli1) exerts a regulatory role on cardiovascular diseases, and it is already a therapeutic target to combat tumors. Our research aimed to explore the role and basic mechanism of Gli1 in CAVD, to pave the way for the discovery of effective drugs in the treatment of CAVD. Human aortic valve tissues were obtained to evaluate Gli1 expression and primary valve interstitial cells (VICs) were used to perform related experiments. The results showed that Gli1 promoted cell proliferation and significantly accelerated cell osteogenic transformation through the up-regulation of the osteogenic factors Runx2 and Alp, in turn through the AKT signaling pathway by targeting P130cas expression. Furthermore, Gli1 was activated by TGF-β and sonic hedgehog through the canonical and non-canonical Hedgehog signaling pathways in VICs. Our results indicated that Gli1 promoted cell proliferation and accelerated cell osteogenic transformation in VICs, providing a new strategy for the therapy of CAVD by targeting Gli1.

Transcriptomic analysis reveals crucial regulatory roles of immediate-early response genes and related signaling pathways in coronavirus infectious bronchitis virus infection

Coronavirus infection of cells differentially regulates the expression of host genes and their related pathways. In this study, we present the transcriptomic profile of cells infected with gammacoronavirus infectious bronchitis virus (IBV). In IBV-infected human non-small cell lung carcinoma cells (H1299 cells), a total of 1162 differentially expressed genes (DEGs), including 984 upregulated and 178 downregulated genes, was identified. These DEGs were mainly enriched in MAPK and Wnt signaling pathways, and 5 out of the 10 top upregulated genes in all transcripts were immediate-early response genes (IEGs). In addition, the induction of 11 transcripts was validated in IBV-infected H1299 and Vero cells by RT-qPCR. The accuracy, reliability and genericity of the transcriptomic data were demonstrated by functional characterization of these IEGs in cells infected with different coronaviruses in our previous publications. This study provides a reliable transcriptomic profile of host genes and pathways regulated by coronavirus infection.

Loss of MEG3 and upregulation of miR-145 play an important role in the invasion and migration of Cr(VI)-transformed cells

Chronic exposure of human bronchial epithelial BEAS-2B cells to hexavalent chromium (Cr(VI)) causes malignant cell transformation. These transformed cells exhibit increases in migration and invasion. Neuronal precursor of developmentally downregulated protein 9 (NEDD9) is upregulated in Cr(VI)-transformed cells compared to that of passage-matched normal BEAS-2B cells. Knockdown of NEDD9 by its shRNA reduced invasion and migration of Cr(VI)-transformed cells. Maternally expressed gene 3 (MEG3), a long noncoding RNA, was lost and microRNA 145 (miR-145) was upregulated in Cr(VI)-transformed cells. MEG3 was bound to miR-145 and this binding reduced its activity. Overexpression of MEG3 or inhibition of miR-145 decreased invasion and migration of Cr(VI)-transformed cells. Overexpression of MEG3 was able to decrease miR-145 level and NEDD9 protein level in Cr(VI)-transformed cells. Ectopic expression of MEG3 was also shown to reduce β-catenin activation. Inhibition of miR-145 in Cr(VI)-transformed cells decreased Slug, an important transcription factor that regulates epithelial-to-mesenchymal transition (EMT). Inhibition of miR-145 was found to increase MEG3 in Cr(VI)-transformed cells. Further studies showed that mutation of MEG3 at the binding site for miR-145 did not change NEDD9 and failed to decrease invasion and migration. The present study demonstrated that loss of MEG3 and upregulation of miR-145 elevated NEDD9, resulting in activation of β-catenin and further upregulation of EMT, leading to increased invasion and migration of Cr(VI)-transformed cells.

Combining Recombinase-Mediated Cassette Exchange Strategy with Quantitative Proteomic and Phosphoproteomic Analyses to Inspect Intracellular Functions of the Tumor Suppressor Galectin-4 in Colorectal Cancer Cells

Galectin-4 (Gal4) has been suggested to function as a tumor suppressor in colorectal cancer (CRC). In order to systematically explore its function in CRC, we established a CRC cell line where Gal4 expression can be regulated via the doxycycline (dox)-inducible expression of a single copy wildtype LGALS4 transgene generated by recombinase-mediated cassette exchange (RMCE). Using this model and applying in-depth proteomic and phosphoproteomic analyses, we systematically screened for intracellular changes induced by Gal4 expression. Overall, 3083 cellular proteins and 2071 phosphosites were identified and quantified, of which 1603 could be matched and normalized to their protein expression levels. A bioinformatic analysis revealed that most of the regulated proteins and phosphosites can be localized in the nucleus and are categorized as nucleic acid-binding proteins. The top candidates whose expression was modulated by Gal4 are PURB, MAPKAPK3, BTF3 and BCAR1, while the prime candidates with altered phosphorylation included ZBTB7A, FOXK1, PURB and CK2beta. In order to validate the (phospho)proteomic data, we confirmed these candidates by a radiometric metabolic-labelling and immunoprecipitation strategy. All candidates exert functions in the transcriptional or translational control, indicating that Gal4 might be involved in these processes by affecting the expression or activity of these proteins.

NEDD9 sustains hexokinase expression to promote glycolysis

Elevated rates of glycolysis in cancer cells support tumor growth, in a process that typically depends on oncogene-induced increases in the expression and/or activity of enzymes in the glycolytic pathway. The NEDD9 scaffolding protein is upregulated in many advanced tumors, with increased NEDD9 promoting the activity of SRC and other effectors that promote invasion and metastasis. We here define a new role for NEDD9 in support of glycolysis. NEDD9 knockdown significantly impaired glycolysis in multiple lung cancer cell lines This was accompanied by post-transcriptional downregulation of steady-state levels of hexokinases (HK1 and HK2), which catalyze early steps in the glycolytic cascade, key rate limiting enzyme phosphofructokinase (PFK1), and downstream glyceraldehyde phosphate dehydrogenase (GAPDH). In mice, protein levels of HK1, HK2, PFK1, and GAPDH were depressed in Krastm4Tyj/J/Trp53tm1Brn/J (KP) non-small cell lung tumors with null versus wild type Nedd9. Reciprocally, depletion of HK1 or HK2 elevated NEDD9 expression, as did the treatment of cells with 2-deoxyglucose (2DG), an inhibitor of glycolysis; whereas overexpression of hexokinases promoted NEDD9 dephosphorylation, associated with reduced NEDD9 activity. Together, these data for the first time suggest a negative feedback circuit involving NEDD9 and glycolytic enzymes that may contribute to NEDD9 action in promoting the aggressive growth of advanced tumors.

Docking Protein p130Cas Regulates Acinar to Ductal Metaplasia During Pancreatic Adenocarcinoma Development and Pancreatitis

BACKGROUND & AIMS

Acinar to ductal metaplasia is the prerequisite for the initiation of Kras-driven pancreatic ductal adenocarcinoma (PDAC), and candidate genes regulating this process are emerging from genome-wide association studies. The adaptor protein p130Cas emerged as a potential PDAC susceptibility gene and a Kras-synthetic lethal interactor in pancreatic cell lines; however, its role in PDAC development has remained largely unknown.

METHODS

Human PDAC samples and murine KrasG12D-dependent pancreatic cancer models of increasing aggressiveness were used. p130Cas was conditionally ablated in pancreatic cancer models to investigate its role during Kras-induced tumorigenesis.

RESULTS

We found that high expression of p130Cas is frequently detected in PDAC and correlates with higher histologic grade and poor prognosis. In a model of Kras-driven PDAC, loss of p130Cas inhibits tumor development and potently extends median survival. Deletion of p130Cas suppresses acinar-derived tumorigenesis and progression by means of repressing PI3K-AKT signaling, even in the presence of a worsening condition like pancreatitis.

CONCLUSIONS

Our observations finally demonstrated that p130Cas acts downstream of Kras to boost the PI3K activity required for acinar to ductal metaplasia and subsequent tumor initiation. This demonstrates an unexpected driving role of p130Cas downstream of Kras through PI3K/AKT, thus indicating a rational therapeutic strategy of targeting the PI3K pathway in tumors with high expression of p130Cas.

Comprehensive immunohistochemical analysis of RET, BCAR1, and BCAR3 expression in patients with Luminal A and B breast cancer subtypes

PURPOSE

Breast cancer (BC) is considered a heterogeneous disease composed of distinct subtypes with diverse clinical outcomes. Luminal subtype tumors have the best prognosis, and patients benefit from endocrine therapy. However, resistance to endocrine therapies in BC is an obstacle to successful treatment, and novel biomarkers are needed to understand and overcome this mechanism. The RET, BCAR1, and BCAR3 genes may be associated with BC progression and endocrine resistance.

METHODS

Aiming to evaluate the expression profile and prognostic value of RET, BCAR1, and BCAR3, we performed immunohistochemistry on tissue microarrays (TMAs) containing a cohort of 361 Luminal subtype BC.

RESULTS

Low expression levels of these three proteins were predominantly observed. BCAR1 expression was correlated with nuclear grade (p = 0.057), and BCAR3 expression was correlated with lymph node status (p = 0.011) and response to hormonal therapy (p = 0.021). Further, low expression of either BCAR1 or BCAR3 was significantly associated with poor prognosis (p = 0.005; p = 0.042). Pairwise analysis showed that patients with tumors with low BCAR1/low BCAR3 expression had a poorer overall survival (p = 0.013), and the low BCAR3 expression had the worst prognosis with RET high expression stratifying these patients into two different groups. Regarding the response to hormonal therapy, non-responder patients presented lower expression of RET in comparison to the responder group (p = 0.035). Additionally, the low BCAR1 expression patients had poorer outcomes than BCAR1 high (p = 0.015).

CONCLUSION

Our findings suggest RET, BCAR1, and BCAR3 as potential candidate markers for endocrine therapy resistance in Luminal BC.

p130Cas Is Correlated with EREG Expression and a Prognostic Factor Depending on Colorectal Cancer Stage and Localization Reducing FOLFIRI Efficacy

p130 Crk-associated substrate (p130Cas) is associated with poor prognosis and treatment resistance in breast and lung cancers. To elucidate p130Cas functional and clinical role in colorectal cancer (CRC) progression/therapy resistance, we performed cell culture experiments and bioinformatic/statistical analyses of clinical data sets. p130Cas expression was associated with poor survival in the cancer genome atlas (TCGA) data set. Knockdown/reconstitution experiments showed that p130Cas drives migration but, unexpectedly, inhibits proliferation in CRC cells. TCGA data analyses identified the growth factor epiregulin (EREG) as inversely correlated with p130Cas. p130Cas knockdown and simultaneous EREG treatment further enhanced proliferation. RNA interference and EREG treatment experiments suggested that p130Cas/EREG limit each other’s expression/activity. Inverse p130Cas/EREG Spearman correlations were prominent in right-sided and earlier stage CRC. p130Cas was inducible by 5-fluorouracil (5-FU) and FOLFIRI (folinic acid, 5-FU, irinotecan), and p130Cas and EREG were upregulated in distant metastases (GSE121418). Positive p130Cas/EREG correlations were observed in metastases, preferentially in post-treatment samples (especially pulmonary metastases). p130Cas knockdown sensitized CRC cells to FOLFIRI independent of EREG treatment. RNA sequencing and gene ontology analyses revealed that p130Cas is involved in cytochrome P450 drug metabolism and epithelial-mesenchymal transition. p130Cas expression was associated with poor survival in right-sided, stage I/II, MSS (microsatellite stable), or BRAF-mutated CRC. In summary, p130Cas represents a prognostic factor and potential therapeutic target in CRC.

p130Cas/BCAR1 and p140Cap/SRCIN1 Adaptors: The Yin Yang in Breast Cancer?

p130Cas/BCAR1 is an adaptor protein devoid of any enzymatic or transcriptional activity, whose modular structure with various binding motifs, allows the formation of multi-protein signaling complexes. This results in the induction and/or maintenance of signaling pathways with pleiotropic effects on cell motility, cell adhesion, cytoskeleton remodeling, invasion, survival, and proliferation. Deregulation of p130Cas/BCAR1 adaptor protein has been extensively demonstrated in a variety of human cancers in which overexpression of p130Cas/BCAR1 correlates with increased malignancy. p140Cap (p130Cas associated protein), encoded by the SRCIN1 gene, has been discovered by affinity chromatography and mass spectrometry analysis of putative interactors of p130Cas. It came out that p140Cap associates with p130Cas not directly but through its interaction with the Src Kinase. p140Cap is highly expressed in neurons and to a lesser extent in epithelial tissues such as the mammary gland. Strikingly, in vivo and in vitro analysis identified its tumor suppressive role in breast cancer and in neuroblastoma, showing an inverse correlation between p140Cap expression in tumors and tumor progression. In this review, a synopsis of 15 years of research on the role of p130Cas/BCAR1 and p140Cap/SRCIN1 in breast cancer will be presented.

The unique function of p130Cas in regulating the bone metabolism

p130 Crk-associated substrate (Cas) functions as an adapter protein and plays important roles in certain cell functions, such as cell proliferation, spreading, migration, and invasion. Furthermore, it has recently been reported to have a new function as a mechanosensor. Since bone is a tissue that is constantly under gravity, it is exposed to mechanical stress. Mechanical unloading, such as in a microgravity environment in space or during bed rest, leads to a decrease in bone mass because of the suppression of bone formation and the stimulation of bone resorption. Osteoclasts are multinucleated bone-resorbing giant cells that recognize bone and then form a ruffled border in the resorption lacuna. p130Cas is a molecule located downstream of c-Src that is important for the formation of a ruffled border in osteoclasts. Indeed, osteoclast-specific p130Cas-deficient mice exhibit osteopetrosis due to osteoclast dysfunction, similar to c-Src-deficient mice. Osteoblasts subjected to mechanical stress induce both the phosphorylation of p130Cas and osteoblast differentiation. In osteocytes, mechanical stress regulates bone mass by shuttling p130Cas between the cytoplasm and nucleus. Oral squamous cell carcinoma (OSCC) cells express p130Cas more strongly than epithelial cells in normal tissues. The knockdown of p130Cas in OSCC cells suppressed the cell growth, the expression of receptor activator of NF-κB ligand, which induces osteoclast formation, and bone invasion by OSCC. Taken together, these findings suggest that p130Cas might be a novel therapeutic target molecule in bone diseases, such as osteoporosis, rheumatoid arthritis, bone loss due to bed rest, and bone invasion and metastasis of cancer.

A Cas-BCAR3 co-regulatory circuit controls lamellipodia dynamics

Integrin adhesion complexes regulate cytoskeletal dynamics during cell migration. Adhesion activates phosphorylation of integrin-associated signaling proteins, including Cas (p130Cas, BCAR1), by Src-family kinases. Cas regulates leading-edge protrusion and migration in cooperation with its binding partner, BCAR3. However, it has been unclear how Cas and BCAR3 cooperate. Here, using normal epithelial cells, we find that BCAR3 localization to integrin adhesions requires Cas. In return, Cas phosphorylation, as well as lamellipodia dynamics and cell migration, requires BCAR3. These functions require the BCAR3 SH2 domain and a specific phosphorylation site, Tyr 117, that is also required for BCAR3 downregulation by the ubiquitin-proteasome system. These findings place BCAR3 in a co-regulatory positive-feedback circuit with Cas, with BCAR3 requiring Cas for localization and Cas requiring BCAR3 for activation and downstream signaling. The use of a single phosphorylation site in BCAR3 for activation and degradation ensures reliable negative feedback by the ubiquitin-proteasome system.

Integrated Analysis of ceRNA Network Reveals Prognostic and Metastasis Associated Biomarkers in Breast Cancer

Background

Breast cancer is a malignancy and lethal tumor in women. Metastasis of breast cancer is one of the causes of poor prognosis. Increasing evidences have suggested that the competing endogenous RNAs (ceRNAs) were associated with the metastasis of breast cancer. Nonetheless, potential roles of ceRNAs in regulating the metastasis of breast cancer remain unclear.

Methods

The RNA expression (3 levels) and follow-up data of breast cancer and noncancerous tissue samples were downloaded from the Cancer Genome Atlas (TCGA). Differentially expressed and metastasis associated RNAs were identified for functional analysis and constructing the metastasis associated ceRNA network by comprehensively bioinformatic analysis. The Kaplan-Meier (K-M) survival curve was utilized to screen the prognostic RNAs in metastasis associated ceRNA network. Moreover, we further identified the metastasis associated biomarkers with operating characteristic (ROC) curve. Ultimately, the data of Cancer Cell Line Encyclopedia (CCLE, https://portals.broadinstitute.org/ccle) website were selected to obtained the reliable metastasis associated biomarkers.

Results

1005 mRNAs, 22 miRNAs and 164 lncRNAs were screened as differentially expressed and metastasis associated RNAs. The results of GO function and KEGG pathway enrichment analysis showed that these RNAs are mainly associated with the metabolic processes and stress responses. Next, a metastasis associated ceRNA (including 104 mRNAs, 19 miRNAs, and 16 lncRNAs) network was established, and 12 RNAs were found to be related to the overall survival (OS) of patients. In addition, 3 RNAs (hsa-miR-105-5p, BCAR1, and PANX2) were identified to serve as reliable metastasis associated biomarkers. Eventually, the results of mechanism analysis suggested that BCAR1 might promote the metastasis of breast cancer by facilitating Rap 1 signaling pathway.

Conclusion

In the present research, we identified 3 RNAs (hsa-miR-105-5p, BCAR1 and PANX2) might associated with prognosis and metastasis of breast cancer, which might be provide a new perspective for metastasis of breast cancer and contributed to the treatment of breast cancer.

Wnt5a-induced docking of Plk1 on HEF1 promotes HEF1 translocation and tumorigenesis

BACKGROUND

Upregulation of human enhancer filamentation 1 (HEF1/NEDD9/Cas-L) and Polo-like kinase 1 (Plk1) is closely correlated with metastasis of human cancer. However, the mechanism by which the overexpression of HEF1 or Plk1 stimulates cancer metastasis and induces tumorigenesis remains enigmatic. In addition, the accumulation of HEF1 at the focal adhesion (FA) is known to be an essential event in cancer cell migration, but the mechanism of how HEF1 is targeted to the FA remains yet to be unveiled.

OBJECTIVE

This study was performed to elucidate the FA docking mechanism of HEF1 and to determine its effect on tumorigenesis.

METHODS

To confirm the effect of the kinase on HEF1 translocation, various expression-knockdown stable cell lines were generated using a lentivirus system, and the effect of the HEF1-Plk1 complex on tumorigenesis was confirmed using a xenograft mouse model.

RESULTS

Here, we show that Wnt5a-dependent Plk1 binding to HEF1 is critically required for HEF1 translocation to the FA. We also confirmed that Plk1 and CK1δ activities essential for HEF1 translocation are induced by Wnt5a. Finally, we confirmed the induction of tumorigenesis by the HEF1-Plk1 complex in the xenograft mouse model.

CONCLUSION

Our data collectively unveil the Wnt5a-CK1δ-HEF1-Plk1-FA remodeling pathway that governs HEF1 transportation to the FA to induce cell migration and tumorigenesis. This study sheds light on a mechanism underlying tumorigenesis and provides new strategies for anticancer therapy.

Cystic Fibrosis-Related Diabetes (CFRD): Overview of Associated Genetic Factors

Cystic fibrosis (CF) is the most common autosomal recessive disease in the Caucasian population and is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene that encodes for a chloride/bicarbonate channel expressed on the membrane of epithelial cells of the airways and of the intestine, as well as in cells with exocrine and endocrine functions. A common nonpulmonary complication of CF is cystic fibrosis-related diabetes (CFRD), a distinct form of diabetes due to insulin insufficiency or malfunction secondary to destruction/derangement of pancreatic betacells, as well as to other factors that affect their function. The prevalence of CFRD increases with age, and 40–50% of CF adults develop the disease. Several proposed hypotheses on how CFRD develops have emerged, including exocrine-driven fibrosis and destruction of the entire pancreas, as well as contrasting theories on the direct or indirect impact of CFTR mutation on islet function. Among contributors to the development of CFRD, in addition to CFTR genotype, there are other genetic factors related and not related to type 2 diabetes. This review presents an overview of the current understanding on genetic factors associated with glucose metabolism abnormalities in CF.

Global transcriptome study of Dip2B-deficient mouse embryonic lung fibroblast reveals its important roles in cell proliferation and development

Disco-interacting protein 2 homolog B (Dip2B) is a member of Dip2 family encoded by Dip2b gene. Dip2B has been reported to regulate murine epithelial KIT⁺ progenitor cell expansion and differentiation epigenetically via exosomal miRNA targeting during salivary gland organogenesis. However, its molecular functions, cellular activities and biological process remain unstudied. Here, we investigated the transcriptome of Dip2B-deficient mouse embryonic lung fibroblasts (MELFs) isolated from E14.5 embryos by RNA-Seq. Expression profiling identified 1369 and 1104 differentially expressed genes (DEGs) from Dip2b^−/− and Dip2b^+/− MELFs in comparisons to wild-type (Dip2b^+/+). Functional clustering of DEGs revealed that many gene ontology terms belong to membrane activities such as ‘integral component of plasma membrane’, and ‘ion channel activity’, suggesting possible roles of Dip2B in membrane integrity and membrane function. KEGG pathway analysis revealed that multiple metabolic pathways are affected in Dip2b^−/− and Dip2b^+/− when compared to Dip2b^+/+ MELFs. These include ‘protein digestion and absorption’, ‘pancreatic secretion’ and ‘steroid hormone synthesis pathway’. These results suggest that Dip2B may play important roles in metabolism. Molecular function analysis shows transcription factors including Hox-genes, bHLH-genes, and Forkhead-genes are significantly down-regulated in Dip2b^−/− MELFs. These genes are critical in embryo development and cell differentiation. In addition, Dip2B-deficient MELFs demonstrated a reduction in cell proliferation and migration, and an increase in apoptosis. All results indicate that Dip2B plays multiple roles in cell proliferation, migration and apoptosis during embryogenesis and may participate in control of metabolism. This study provides valuable information for further understanding of the function and regulatory mechanisms of Dip2B.

BCAR1 promotes proliferation and cell growth in lung adenocarcinoma via upregulation of POLR2A

BACKGROUND

This study was designed to investigate the effects of a novel carcinogenetic molecule, p130cas (breast cancer antiestrogen resistance protein 1 or BCAR1) on proliferation and cell growth in lung adenocarcinoma. The study also aimed to identify the possible underlying signal networks of BCAR1.

METHODS

First, we evaluated proliferation, cell colony formation, apoptosis, and cell cycle after BCAR1 was knocked out (KO) using CRISPR-Cas9 technology in H1975 and H1299 human lung adenocarcinoma cells. Subsequently, BCAR1 was upregulated in 293T cells and immunoprecipitation-mass spectrometry (IP-MS) was used with bioinformatics analysis to screen for potential networks of BCAR1 interacting proteins. Ultimately, we validated the correlated expressions of BCAR1 and a selected hub gene, RNA polymerase II subunit A (POLR2A), in 54 lung adenocarcinoma tissues, as well as in H1975 and H1299 cells.

RESULTS

Cell proliferation of H1975 and H1299 was significantly inhibited following BCAR1-KO. Colony formation of H1975 cells was also significantly decreased following BCAR1-KO. IP-MS demonstrated 419 potential proteins that may interact with BCAR1. Among them, 68 genes were significantly positively correlated to BCAR1 expression, as verified by TCGA. Six hub genes were revealed by PPI String. High expression of POLR2A, MAPK3, MOV10, and XAB2 predicted poor prognosis in lung adenocarcinoma, as verified by the K-M plotter database. POLR2A and MAPK3 are involved in both catalytic activity and transferase activity. POLR2A and BCAR1 were significantly increased in lung cancer tissues as compared with matched normal tissues. High expression of POLR2A was significantly positively correlated to BCAR1 overexpression and predicted poor prognosis in 54 lung cancer cases. POLR2A expression was significantly decreased following BCAR1-KO in H1975 and H1299 cells.

CONCLUSIONS

BCAR1 promotes proliferation and cell growth, probably via upregulation of POLR2A and subsequent enhancement of catalytic and transferase activities. However, additional robust studies are required to elucidate the mechanisms involved.

Global profiling of lncRNAs-miRNAs-mRNAs reveals differential expression of coding genes and non-coding RNAs in the lung of beagle dogs at different stages of Toxocara canis infection

The roundworm Toxocara canis causes toxocariasis in dogs and larval migrans in humans. Better understanding of the lung response to T. canis infection could explain why T. canis must migrate to and undergoes part of its development inside the lung of the definitive host. In this study, we profiled the expression patterns of long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and mRNAs in the lungs of Beagle dogs infected by T. canis, using high throughput RNA sequencing. At 24 h p.i., 1,012 lncRNAs, 393 mRNAs and 10 miRNAs were differentially expressed (DE). We also identified 883 DElncRNAs, 264 DEmRNAs and 20 DEmiRNAs at 96 h p.i., and 996 DElncRNAs, 342 DEmRNAs and eight DEmiRNAs at 36 days p.i., between infected and control dogs. Significant changes in the levels of expression of transcripts related to immune response and inflammation were associated with the antiparasitic response of the lung to T. canis. The remarkable increase in the expression of scgb1a1 at all time points after infection suggests the need for consistent moderation of the excessive inflammatory response. Also, upregulation of foxj1 at 24 h p.i., and downregulation of IL-1β and IL-21 at 96 h p.i., suggest an attenuation of the humoral immunity of infected dogs. These results indicate that T. canis pathogenesis in the lung is mediated through contributions from both pro-inflammatory and anti-inflammatory mechanisms. Competing endogenous RNA (ceRNA) network analysis revealed significant interactions between DElncRNAs, DEmiRNAs and DEmRNAs, and improved our understanding of the ceRNA regulatory mechanisms in the context of T. canis infection. These data provide comprehensive understanding of the regulatory networks that govern the lung response to T. canis infection and reveal new mechanistic insights into the interaction between the host and parasite during the course of T. canis infection in the canine.

P130Cas/bcar1 mediates zebrafish caudal vein plexus angiogenesis

P130CAS/BCAR1 belongs to the CAS family of adaptor proteins, with important regulatory roles in cell migration, cell cycle control, and apoptosis. Previously, we and others showed that P130CAS mediates VEGF-A and PDGF signalling in vitro, but its cardiovascular function in vivo remains relatively unexplored. We characterise here a novel deletion model of P130CAS in zebrafish. Using in vivo microscopy and transgenic vascular reporters, we observed that while bcar1−/− zebrafish showed no arterial angiogenic or heart defects during development, they strikingly failed to form the caudal vein plexus (CVP). Endothelial cells (ECs) within the CVP of bcar1−/− embryos produced fewer filopodial structures and did not detach efficiently from neighbouring cells, resulting in a significant reduction in ventral extension and overall CVP area. Mechanistically, we show that P130Cas mediates Bmp2b-induced ectopic angiogenic sprouting of ECs in the developing embryo and provide pharmacological evidence for a role of Src family kinases in CVP development.

CSRP2 suppresses colorectal cancer progression via p130Cas/Rac1 axis-meditated ERK, PAK, and HIPPO signaling pathways

Metastasis is a major cause of death in patients with colorectal cancer (CRC). Cysteine-rich protein 2 (CSRP2) has been recently implicated in the progression and metastasis of a variety of cancers. However, the biological functions and underlying mechanisms of CSRP2 in the regulation of CRC progression are largely unknown.

Methods: Immunohistochemistry, quantitative real-time polymerase chain reaction (qPCR) and Western blotting (WB) were used to detect the expression of CSRP2 in CRC tissues and paracancerous tissues. CSRP2 function in CRC was determined by a series of functional tests in vivo and in vitro. WB and immunofluorescence were used to determine the relation between CSRP2 and epithelial-mesenchymal transition (EMT). Co-immunoprecipitation and scanning electron microscopy were used to study the molecular mechanism of CSRP2 in CRC.

Results: The CSRP2 expression level in CRC tissues was lower than in adjacent normal tissues and indicated poor prognosis in CRC patients. Functionally, CSRP2 could suppress the proliferation, migration, and invasion of CRC cells in vitro and inhibit CRC tumorigenesis and metastasis in vivo. Mechanistic investigations revealed a physical interaction between CSRP2 and p130Cas. CSRP2 could inhibit the activation of Rac1 by preventing the phosphorylation of p130Cas, thus activating the Hippo signaling pathway, and simultaneously inhibiting the ERK and PAK/LIMK/cortactin signaling pathways, thereby inhibiting the EMT and metastasis of CRC. Rescue experiments showed that blocking the p130Cas and Rac1 activation could inhibit EMT induced by CSRP2 silencing.

Conclusion: Our results suggest that the CSRP2/p130Cas/Rac1 axis can inhibit CRC aggressiveness and metastasis through the Hippo, ERK, and PAK signaling pathways. Therefore, CSRP2 may be a potential therapeutic target for CRC.

Cyclooxygenase 2-Regulated Genes an Alternative Avenue to the Development of New Therapeutic Drugs for Colorectal Cancer

Colorectal cancer (CRC) is one of the most common and recurrent types of cancer, with high mortality rates. Several clinical trials and meta-analyses have determined that the use of pharmacological inhibitors of cyclooxygenase 2 (COX-2), the enzyme that catalyses the rate-limiting step in the synthesis of prostaglandins (PG) from arachidonic acid, can reduce the incidence of CRC as well as the risk of recurrence of this disease, when used together with commonly used chemotherapeutic agents. These observations suggest that inhibition of COX-2 may be useful in the treatment of CRC, although the current drugs targeting COX-2 are not widely used since they increase the risk of health complications. To overcome this difficulty, a possibility is to identify genes regulated by COX-2 activity that could give an advantage to the cells to form tumors and/or metastasize. The modulation of those genes as effectors of COX-2 may cancel the beneficial effects of COX-2 in tumor transformation and metastasis. A review of the available databases and literature and our own data have identified some interesting molecules induced by prostaglandins or COX-2 that have been also described to play a role in colon cancer, being thus potential pharmacological targets in colon cancer. Among those mPGES-1, DUSP4, and 10, Programmed cell death 4, Trop2, and many from the TGFβ and p53 pathways have been identified as genes upregulated in response to COX-2 overexpression or PGs in colon carcinoma lines and overexpressed in colon tumor tissue. Here, we review the available evidence of the potential roles of those molecules in colon cancer in the context of PG/COX signaling pathways that could be critical mediators of some of the tumor growth and metastasis advantage induced by COX-2. At the end, this may allow defining new therapeutic targets/drugs against CRC that could act specifically against tumor cells and would be effective in the prevention and treatment of CRC, lacking the unwanted side effects of COX-2 pharmacological inhibitors, providing alternative approaches in colon cancer.

Insights into the non-mitotic functions of Aurora kinase A: more than just cell division

AURKA is a serine/threonine kinase overexpressed in several cancers. Originally identified as a protein with multifaceted roles during mitosis, improvements in quantitative microscopy uncovered several non-mitotic roles as well. In physiological conditions, AURKA regulates cilia disassembly, neurite extension, cell motility, DNA replication and senescence programs. In cancer-like contexts, AURKA actively promotes DNA repair, it acts as a transcription factor, promotes cell migration and invasion, and it localises at mitochondria to regulate mitochondrial dynamics and ATP production. Here we review the non-mitotic roles of AURKA, and its partners outside of cell division. In addition, we give an insight into how structural data and quantitative fluorescence microscopy allowed to understand AURKA activation and its interaction with new substrates, highlighting future developments in fluorescence microscopy needed to better understand AURKA functions in vivo. Last, we will recapitulate the most significant AURKA inhibitors currently in clinical trials, and we will explore how the non-mitotic roles of the kinase may provide new insights to ameliorate current pharmacological strategies against AURKA overexpression.

POSITIVE EXPRESSION OF NEDD9 IN HEAD AND NECK CANCER IS RELATED TO BETTER SURVIVAL PERIOD

The aim was to determine immunohistochemical expression of NEDD9 protein in head and neck squamous cell carcinoma (HNSCC) and the possible relation of its expression with primary tumor size (T), regional lymph node status (N), stage of disease (TNM) and survival period. A total of 131 patients with primary tumor localization in the area of oropharynx, hypopharynx and larynx, monitored for at least 5 years after initial surgical treatment were analyzed. The study included 128 male and three female patients, median age 62.0 (range 53.0-68.0) years. Of these, 105 (95%) patients showed positive NEDD9 expressed by dyed cytoplasm. There were no significant differences in NEDD9 expression according to TNM tumor status. Patients with positive NEDD9 expression had a significantly higher median (IQR) survival time 51.0 (15.0-60.0) months as compared to 22.5 (9.0-55.0) months in patients with negative NEDD9 expression (p=0.048). NEDD9 negative expression, controlled for the influence of other variables included in the Cox’s proportional hazards model, had a significant hazard ratio (HR) of 2.10 (95% CI: 1.23-3.58; p=0.006). The results of our study showed that NEDD9 expression might be an independent prognostic marker in patients with HNSCC regarding data on overall survival and mortality.

NEDD9 promotes invasion and migration of colorectal cancer cell line HCT116 via JNK/EMT

Neural precursor cell-expressed, developmentally-downregulated 9 (NEDD9) is a multi-domain skeleton protein that serves an important role in the cell signaling process via modulating invasion, metastasis, proliferation and apoptosis of tumor cells. The present study identified that the expression levels of NEDD9 in colorectal cancer were elevated. Therefore, the effect of downregulating the expression of NEDD9 in terms of invasion and migration of colorectal cancer cells was investigated and the role of the JNK pathway in these processes was also investigated. The data revealed that downregulation of NEDD9 and JNK inhibitors suppressed invasion and migration, decreased expression levels of phosphorylated JNK, increased the expression levels of E-cadherin and decreased the expression levels of vimentin. In summary, NEDD9 promotes invasion and migration of colorectal cancer cells via the JNK pathway.

Histone modification in the lung injury and recovery of mice in response to PM2.5 exposure

Epidemiological and experimental studies have progressively provided a better knowledge of the underlying mechanisms by which fine particulate matter (PM_2.5) exerts its harmful health effects. However, limited studies focused on the effect and following recovery after the particulate exposure ended. In this study, we determined PM_2.5 exposure-caused effects on the lung and their recovery in mice after terminating aspiration, and clarified the possible molecular modification. The results revealed that PM_2.5 exposure for 4 weeks significantly decreased the lung function, and the changes returned to normal levels after 1-week recovery. However, we observed persistent particle alveolar load following 2-week recovery. Interestingly, the alterations of H3K27ac expression and related enzyme activities mimicked the changes of respiratory function during the process, and chromatin immunoprecipitation-seqences (ChIP-seq) suggested that these PM_2.5-associated differential H3K27ac markers participated in immune responses and chemokine signaling pathway with stat2 and bcar1 being two important genes. Consistently, the expression of pro-inflammatory cytokines and chemokines elevated after PM_2.5 exposure for 4-week, and reversed to normal levels following 2-week recovery. The study highlighted that PM_2.5 aspiration caused histone modification associated lung dysfunction and inflammation, and the action restored after exposure ending and 2-week recovery. Also, persistent particle alveolar load might be a long-term potential risk for lung diseases.

Expression of Nedd9 in Transbronchial Biopsies of Lung Adenocarcinoma

SUMMARY – Lung cancer as the major cause of cancer mortality worldwide includes several histologic subtypes evolving from numerous genetic and epigenetic changes emerging in alveolar, bronchiolar and bronchial epithelium. The majority of cases are diagnosed in advanced stage (i.e. stages IIIB and IV), often with scanty amount of tissue in transbronchial biopsies or cytology specimens. The aim of the present study was to investigate the expression of the scaffolding protein neural precursor cell expressed, developmentally downregulated 9 (NEDD9) in small biopsies of lung adenocarcinoma. The expression of NEDD9 was analyzed immunohistochemically in 71 formalin-fixed and paraffin-embedded transbronchial biopsy specimens of primary lung adenocarcinoma. Nuclear and cytoplasmic NEDD9 expression was detected indicating activation of the epithelial-mesenchymal transition process. Direct relationship between the expression of NEDD9 and survival was not demonstrated.

E-cadherin and NEDD9 expression in primary colorectal cancer, metastatic lymph nodes and liver metastases

In Croatia, colorectal cancer mortality rates in males are the third highest in Europe, after Hungary and Slovakia. The results for females rank Croatia in second place after Hungary. According to previous studies, the loss of E-cadherin expression and the higher expression of neural precursor cell-expressed developmentally downregulated 9 (NEDD9) are associated with a worse prognosis. The aim of the present study was to analyze the immunohistochemical expression of NEDD9 and E-cadherin as markers of metastatic potential using a tissue microarray. This retrospective study included 40 previously untreated patients, including 23 males and 17 females with a median age of 64.5 years (range 38–84), with colorectal cancer and synchronous liver metastases that underwent simultaneous colorectal and hepatic resection between January 1st 2006 and December 31st 2013, in the Clinical Hospital Center Sestre Milosrdnice (Zagreb, Croatia). The most frequent tumor stage was T3, while the most frequent nodal stage was N1. Microvascular invasion was present in 37.5% of patients, while perineural invasion was observed in 30% of patients. The immunohistochemical staining index of E-cadherin was highly positive in 87.5% samples of colorectal cancer, 67.7% of lymph nodes and 77.5% of liver metastases. In the primary tumor, highly positive NEDD9 expression was identified in 22.5% of patients. In lymph nodes, it was identified in 35.5% of patients, while in the liver, it was identified in 30% of patients. Significant positive correlations were observed between the percentage of positive lymph nodes and the immunohistochemical staining index of E-cadherin (ρ=0.372; P=0.039) and NEDD9 (ρ=0.451; P=0.011) in lymph nodes. After the conclusion of the study, 55% of the patients succumbed. No significant differences in survival rates were identified regarding the expression of E-cadherin and NEDD9 in the primary tumor, metastatic lymph nodes and liver metastases. Due to the small sample size and the negative results obtained, further research is required to implement these parameters as prognostic factors.

The interaction of p130Cas with PKN3 promotes malignant growth

Protein p130Cas constitutes an adaptor protein mainly involved in integrin signaling downstream of Src kinase. Owing to its modular structure, p130Cas acts as a general regulator of cancer cell growth and invasiveness induced by different oncogenes. However, other mechanisms of p130Cas signaling leading to malignant progression are poorly understood. Here, we show a novel interaction of p130Cas with Ser/Thr kinase PKN3, which is implicated in prostate and breast cancer growth downstream of phosphoinositide 3‐kinase. This direct interaction is mediated by the p130Cas SH3 domain and the centrally located PKN3 polyproline sequence. PKN3 is the first identified Ser/Thr kinase to bind and phosphorylate p130Cas and to colocalize with p130Cas in cell structures that have a pro‐invasive function. Moreover, the PKN3–p130Cas interaction is important for mouse embryonic fibroblast growth and invasiveness independent of Src transformation, indicating a mechanism distinct from that previously characterized for p130Cas. Together, our results suggest that the PKN3–p130Cas complex represents an attractive therapeutic target in late‐stage malignancies.

Conditional ablation of p130Cas/BCAR1 adaptor protein impairs epidermal homeostasis by altering cell adhesion and differentiation

Background

p130 Crk-associated substrate (p130CAS; also known as BCAR1) is a scaffold protein that modulates many essential cellular processes such as cell adhesion, proliferation, survival, cell migration, and intracellular signaling. p130Cas has been shown to be highly expressed in a variety of human cancers of epithelial origin. However, few data are available regarding the role of p130Cas during normal epithelial development and homeostasis.

Methods

To this end, we have generated a genetically modified mouse in which p130Cas protein was specifically ablated in the epidermal tissue.

Results

By using this murine model, we show that p130Cas loss results in increased cell proliferation and reduction of cell adhesion to extracellular matrix. In addition, epidermal deletion of p130Cas protein leads to premature expression of “late” epidermal differentiation markers, altered membrane E-cadherin/catenin proteins localization and aberrant tyrosine phosphorylation of E-cadherin/catenin complexes. Interestingly, these alterations in adhesive properties in absence of p130Cas correlate with abnormalities in progenitor cells balance resulting in the amplification of a more committed cell population.

Conclusion

Altogether, these results provide evidence that p130Cas is an important regulator of epidermal cell fate and homeostasis.

Electronic supplementary material

The online version of this article (10.1186/s12964-018-0289-z) contains supplementary material, which is available to authorized users.

Differential transcriptional changes in human alveolar epithelial A549 cells exposed to airborne PM2.5 collected from Shanghai, China

Fine particulate matters (PM_2.5) are the core pollutants of haze episode, which pose a serious threat to the human health of developing countries. However, the mechanisms involved in PM_2.5-induced hazard influence are not to fully elucidated. In the present study, human lung epithelial cells (A549) were exposed to various concentrations of PM_2.5 samples collected from Shanghai, China. Illumina RNA-Seq method with transcriptome, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were further employed to identify the detrimental effects of PM_2.5 on A549 cells in vitro. A total of 712 differentially expressed genes were obtained from global transcriptome profiling of A549 cells after PM_2.5 exposure. In addition, GO function enrichment analysis revealed that major differentially expressed genes (DEGs) involved in the biological process of the immune system and the response to the stress. KEGG pathway analysis further proposes that infectious disease, cancers, cardiovascular disease, and immune disease pathway were the key human disease events that occur in A549 cells under PM_2.5 stress. The data obtained here shed light on the related biological process and gene signaling pathways affected by PM_2.5 exposure. This study aids our understanding of the complicated mechanisms related to PM_2.5-induced health effects and is informative for the prevention and treatment of PM_2.5-induced systemic diseases.

Consortium-based genome-wide meta-analysis for childhood dental caries traits

Prior studies suggest dental caries traits in children and adolescents are partially heritable, but there has been no large-scale consortium genome-wide association study (GWAS) to date. We therefore performed GWAS for caries in participants aged 2.5-18.0 years from nine contributing centres. Phenotype definitions were created for the presence or absence of treated or untreated caries, stratified by primary and permanent dentition. All studies tested for association between caries and genotype dosage and the results were combined using fixed-effects meta-analysis. Analysis included up to 19 003 individuals (7530 affected) for primary teeth and 13 353 individuals (5875 affected) for permanent teeth. Evidence for association with caries status was observed at rs1594318-C for primary teeth [intronic within ALLC, odds ratio (OR) 0.85, effect allele frequency (EAF) 0.60, P 4.13e-8] and rs7738851-A (intronic within NEDD9, OR 1.28, EAF 0.85, P 1.63e-8) for permanent teeth. Consortium-wide estimated heritability of caries was low [h2 of 1% (95% CI: 0%: 7%) and 6% (95% CI 0%: 13%) for primary and permanent dentitions, respectively] compared with corresponding within-study estimates [h2 of 28% (95% CI: 9%: 48%) and 17% (95% CI: 2%: 31%)] or previously published estimates. This study was designed to identify common genetic variants with modest effects which are consistent across different populations. We found few single variants associated with caries status under these assumptions. Phenotypic heterogeneity between cohorts and limited statistical power will have contributed; these findings could also reflect complexity not captured by our study design, such as genetic effects which are conditional on environmental exposure.

The arrhythmogenic cardiomyopathy-specific coding and non-coding transcriptome in human cardiac stromal cells

Background

Arrhythmogenic cardiomyopathy (ACM) is a genetic autosomal disease characterized by abnormal cell-cell adhesion, cardiomyocyte death, progressive fibro-adipose replacement of the myocardium, arrhythmias and sudden death. Several different cell types contribute to the pathogenesis of ACM, including, as recently described, cardiac stromal cells (CStCs). In the present study, we aim to identify ACM-specific expression profiles of human CStCs derived from endomyocardial biopsies of ACM patients and healthy individuals employing TaqMan Low Density Arrays for miRNA expression profiling, and high throughput sequencing for gene expression quantification.

Results

We identified 3 miRNAs and 272 genes as significantly differentially expressed at a 5% false discovery rate. Both the differentially expressed genes as well as the target genes of the ACM-specific miRNAs were found to be enriched in cell adhesion-related biological processes. Functional similarity and protein interaction-based network analyses performed on the identified deregulated genes, miRNA targets and known ACM-causative genes revealed clusters of highly related genes involved in cell adhesion, extracellular matrix organization, lipid transport and ephrin receptor signaling.

Conclusions

We determined for the first time the coding and non-coding transcriptome characteristic of ACM cardiac stromal cells, finding evidence for a potential contribution of miRNAs, specifically miR-29b-3p, to ACM pathogenesis or phenotype maintenance.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-4876-6) contains supplementary material, which is available to authorized users.

Exploring the mechanistic insights of Cas scaffolding protein family member 4 with protein tyrosine kinase 2 in Alzheimer's disease by evaluating protein interactions through molecular docking and dynamic simulations

Cas scaffolding protein family member 4 and protein tyrosine kinase 2 are signaling proteins, which are involved in neuritic plaques burden, neurofibrillary tangles, and disruption of synaptic connections in Alzheimer's disease. In the current study, a computational approach was employed to explore the active binding sites of Cas scaffolding protein family member 4 and protein tyrosine kinase 2 proteins and their significant role in the activation of downstream signaling pathways. Sequential and structural analyses were performed on Cas scaffolding protein family member 4 and protein tyrosine kinase 2 to identify their core active binding sites. Molecular docking servers were used to predict the common interacting residues in both Cas scaffolding protein family member 4 and protein tyrosine kinase 2 and their involvement in Alzheimer's disease-mediated pathways. Furthermore, the results from molecular dynamic simulation experiment show the stability of targeted proteins. In addition, the generated root mean square deviations and fluctuations, solvent-accessible surface area, and gyration graphs also depict their backbone stability and compactness, respectively. A better understanding of CAS and their interconnected protein signaling cascade may help provide a treatment for Alzheimer's disease. Further, Cas scaffolding protein family member 4 could be used as a novel target for the treatment of Alzheimer's disease by inhibiting the protein tyrosine kinase 2 pathway.

PTPN12/PTP-PEST Regulates Phosphorylation-Dependent Ubiquitination and Stability of Focal Adhesion Substrates in Invasive Glioblastoma Cells

Glioblastoma (GBM) is an invasive brain cancer with tumor cells that disperse from the primary mass, escaping surgical resection and invariably giving rise to lethal recurrent lesions. Here we report that PTP-PEST, a cytoplasmic protein tyrosine phosphatase, controls GBM cell invasion by physically bridging the focal adhesion protein Crk-associated substrate (Cas) to valosin-containing protein (Vcp), an ATP-dependent protein segregase that selectively extracts ubiquitinated proteins from multiprotein complexes and targets them for degradation via the ubiquitin proteasome system. Both Cas and Vcp are substrates for PTP-PEST, with the phosphorylation status of tyrosine 805 (Y805) in Vcp impacting affinity for Cas in focal adhesions and controlling ubiquitination levels and protein stability. Perturbing PTP-PEST-mediated phosphorylation of Cas and Vcp led to alterations in GBM cell-invasive growth in vitro and in preclinical mouse models. Collectively, these data reveal a novel regulatory mechanism involving PTP-PEST, Vcp, and Cas that dynamically balances phosphorylation-dependent ubiquitination of key focal proteins involved in GBM cell invasion.Significance: PTP-PEST balances GBM cell growth and invasion by interacting with the ATP-dependent ubiquitin segregase Vcp/p97 and regulating phosphorylation and stability of the focal adhesion protein p130Cas.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/14/3809/F1.large.jpg Cancer Res; 78(14); 3809-22. ©2018 AACR.

NEDD9 may regulate hepatocellular carcinoma cell metastasis by promoting epithelial-mesenchymal-transition and stemness via repressing Smad7

Overexpression of neural precursor cell expressed, developmentally downregulated 9 (NEDD9) is a prognostic marker of many cancers, including hepatocellular carcinoma (HCC). However, the functions and mechanisms of NEDD9 are unclear. We found that upregulation of NEDD9 promoted migration, invasion and cell-to-extracellular matrix adhesion of HCC cells. NEDD9 also induced the epithelial-mesenchymal transition (EMT) and expression of matrix metalloprotein 2 (MMP2). Increased aldehyde dehydrogenase (ALDH) activity and CD133-positive cells were observed in HCC cells with high expression of NEDD9, corresponding to greater sphere formation in cancer stem cells (CSCs). NEDD9 deregulated Smad7 expression to inhibit Smad signaling and binding to the FAK-Src-Crk complex. We propose that this is the mechanism by which NEDD9 induced CSC properties.

Phosphorylation of human enhancer filamentation 1 (HEF1) stimulates interaction with Polo-like kinase 1 leading to HEF1 localization to focal adhesions

Elevated expression of human enhancer filamentation 1 (HEF1; also known as NEDD9 or Cas-L) is an essential stimulus for the metastatic process of various solid tumors. This process requires HEF1 localization to focal adhesions (FAs). Although the association of HEF1 with FAs is considered to play a role in cancer cell migration, the mechanism targeting HEF1 to FAs remains unclear. Moreover, up-regulation of Polo-like kinase 1 (Plk1) positively correlates with human cancer metastasis, yet how Plk1 deregulation promotes metastasis remains elusive. Here, we report that casein kinase 1δ (CK1δ) phosphorylates HEF1 at Ser-780 and Thr-804 and that these phosphorylation events promote a physical interaction between Plk1 and HEF1. We found that this interaction is critical for HEF1 translocation to FAs and for inducing migration of HeLa cells. Plk1-docking phosphoepitopes were mapped/confirmed in HEF1 by various methods, including X-ray crystallography, and mutated for functional analysis in HeLa cells. In summary, our results reveal the role of a phosphorylation-dependent HEF1-Plk1 complex in HEF1 translocation to FAs to induce cell migration. Our findings provide critical mechanistic insights into the HEF1-Plk1 complex-dependent localization of HEF1 to FAs underlying the metastatic process and may therefore contribute to the development of new cancer therapies.

Significance of serum neural precursor cell-expressed developmentally downregulated protein 9 in melanoma

Neural precursor cell-expressed developmentally downregulated protein 9 (NEDD9) is a promoter for various cellular functions that result in tumorigenesis. The aim of the present study was to analyse the serum levels of NEDD9 in melanoma patients in order to evaluate its prognostic, predictive and diagnostic value. Data from 112 melanoma patients were retrospectively analyzed and ELISA assays were used to measure serum NEDD9 concentration. The median serum NEDD9 levels of the patients were significantly higher compared with those of the controls. Serum NEDD9 was not found to be associated with any of the clinicopathological parameters, and was also not found to be prognostic for survival in melanoma. Therefore, serum NEDD9 may be of diagnostic value in melanoma, but its usefulness in prognosis remains controversial. The important role of NEDD9 in tumor angiogenesis necessitates efforts to elucidate its interactions with the tumor microenvironment and its potential as a therapeutic target for malignancies.

A genomic exploration identifies mechanisms that may explain adverse cardiovascular effects of COX-2 inhibitors

Cyclooxygenase-2 inhibitors (coxibs) are characterized by multiple molecular off-target effects and increased coronary artery disease (CAD) risk. Here, we systematically explored common variants of genes representing molecular targets of coxibs for association with CAD. Given a broad spectrum of pleiotropic effects of coxibs, our intention was to narrow potential mechanisms affecting CAD risk as we hypothesized that the affected genes may also display genomic signals of coronary disease risk. A Drug Gene Interaction Database search identified 47 gene products to be affected by coxibs. We traced association signals in 200-kb regions surrounding these genes in 84,813 CAD cases and 202,543 controls. Based on a threshold of 1 × 10⁻⁵ (Bonferroni correction for 3131 haplotype blocks), four gene loci yielded significant associations. The lead SNPs were rs7270354 (MMP9), rs4888383 (BCAR1), rs6905288 (VEGFA1), and rs556321 (CACNA1E). By additional genotyping, rs7270354 at MMP9 and rs4888383 at BCAR1 also reached the established GWAS threshold for genome-wide significance. The findings demonstrate overlap of genes affected by coxibs and those mediating CAD risk and points to further mechanisms, which are potentially responsible for coxib-associated CAD risk. The novel approach furthermore suggests that genetic studies may be useful to explore the clinical relevance of off-target drug effects.

NEDD9 expression is correlated with epithelial-to-mesenchymal transition markers in colorectal cancer

The epithelial-to-mesenchymal transition (EMT) is a critical step in tumor metastasis. NEDD9 has been shown to be an oncogene in colorectal cancer. However, little is known about the relationship between NEDD9 and EMT in colorectal cancer metastasis. A total of 63 pairs of freshly frozen colorectal cancer tissues and adjacent noncancerous tissues were evaluated for NEDD9 gene expression using quantitative real-time PCR. The expression of NEDD9 and three epithelial-mesenchymal transition (EMT)-related proteins (E-cadherin, β-catenin and vimentin) was examined in 122 colorectal cancers by immunohistochemistry. The expression of NEDD9 was markedly increased in colorectal cancer tissues compared with adjacent noncancerous tissues. The expression level of NEDD9 was positively correlated and TNM stage but not with other clinicopathological features of colorectal tumors. Furthermore, the expression of NEDD9 was strongly associated with the loss of epithelial marker E-cadherin and acquired expression of the mesenchymal markers nuclear β-catenin and vimentin. These findings suggested that NEDD9 might promote EMT and the progression of colorectal cancer, and thus may be a potential therapeutic target of colorectal cancers.

Chronic Cigarette Smoke Mediated Global Changes in Lung Mucoepidermoid Cells: A Phosphoproteomic Analysis

Proteomics analysis of chronic cigarette smoke exposure is a rapidly emerging postgenomics research field. While smoking is a major cause of lung cancer, functional studies using proteomics approaches could enrich our mechanistic understanding of the elusive lung cancer global molecular signaling and cigarette smoke relationship. We report in this study on a stable isotope labeling by amino acids in cell culture-based quantitative phosphoproteomic analysis of a human lung mucoepidermoid carcinoma cell line, H292 cells, chronically exposed to cigarette smoke. Using high resolution Orbitrap Velos mass spectrometer, we identified the hyperphosphorylation of 493 sites, which corresponds to 341 proteins and 195 hypophosphorylated sites, mapping to 142 proteins upon smoke exposure (2.0-fold change). We report differential phosphorylation of multiple kinases, including PAK6, EPHA4, LYN, mitogen-activated protein kinase, and phosphatases, including TMEM55B, PTPN14, TIGAR, among others, in response to chronic cigarette smoke exposure. Bioinformatics analysis revealed that the molecules differentially phosphorylated upon chronic exposure of cigarette smoke are associated with PI3K/AKT/mTOR and CDC42-PAK signaling pathways. These signaling networks are involved in multiple cellular processes, including cell polarity, cytoskeletal remodeling, cellular migration, protein synthesis, autophagy, and apoptosis. The present study contributes to emerging proteomics insights on cigarette smoke mediated global signaling in lung cells, which in turn may aid in development of precision medicine therapeutics and postgenomics biomarkers.

NEDD9, an independent good prognostic factor in intermediate-risk acute myeloid leukemia patients

Intermediate-risk acute myeloid leukemia (IR-AML) is the largest subgroup of AML patients and is highly heterogeneous. Whereas adverse and favourable risk patients have well-established treatment protocols, IR-AML patients have not. It is, therefore, crucial to find novel factors that stratify this subgroup to implement risk-adapted strategies. The CAS (Crk-associated substrate) adaptor protein family regulates cell proliferation, survival, migration and adhesion. Despite its association with metastatic dissemination and prognosis of different solid tumors, the role of these proteins in hematological malignancies has been scarcely evaluated. Nevertheless, previous work has established an important role for the CAS family members NEDD9 or BCAR1 in the migratory and dissemination capacities of myeloid cells. On this basis, we hypothesized that NEDD9 or BCAR1 expression levels could associate with survival in IR-AML patients and become new prognostic markers. To that purpose, we assessed BCAR1 and NEDD9 gene expression in a cohort of 73 adult AML patients validating the results in an independent cohort (n = 206). We have identified NEDD9, but not BCAR1, as a new a marker for longer overall and disease-free survival, and for lower cumulative incidence of relapse. In summary, NEDD9 gene expression is an independent prognostic factor for favourable prognosis in IR-AML patients.