NEDD9 promotes lung cancer metastasis through epithelial-mesenchymal transition

Identification of New Markers of Angiogenic Sprouting Using Transcriptomics: New Role for RND3

BACKGROUND

New blood vessel formation requires endothelial cells to transition from a quiescent to an invasive phenotype. Transcriptional changes are vital for this switch, but a comprehensive genome-wide approach focused exclusively on endothelial cell sprout initiation has not been reported.

METHODS

Using a model of human endothelial cell sprout initiation, we developed a protocol to physically separate cells that initiate the process of new blood vessel formation (invading cells) from noninvading cells. We used this model to perform multiple transcriptomics analyses from independent donors to monitor endothelial gene expression changes.

RESULTS

Single-cell population analyses, single-cell cluster analyses, and bulk RNA sequencing revealed common transcriptomic changes associated with invading cells. We also found that collagenase digestion used to isolate single cells upregulated the Fos proto-oncogene transcription factor. Exclusion of Fos proto-oncogene expressing cells revealed a gene signature consistent with activation of signal transduction, morphogenesis, and immune responses. Many of the genes were previously shown to regulate angiogenesis and included multiple tip cell markers. Upregulation of SNAI1 (snail family transcriptional repressor 1), PTGS2 (prostaglandin synthase 2), and JUNB (JunB proto-oncogene) protein expression was confirmed in invading cells, and silencing JunB and SNAI1 significantly reduced invasion responses. Separate studies investigated rounding 3, also known as RhoE, which has not yet been implicated in angiogenesis. Silencing rounding 3 reduced endothelial invasion distance as well as filopodia length, fitting with a pathfinding role for rounding 3 via regulation of filopodial extensions. Analysis of in vivo retinal angiogenesis in Rnd3 heterozygous mice confirmed a decrease in filopodial length compared with wild-type littermates.

CONCLUSIONS

Validation of multiple genes, including rounding 3, revealed a functional role for this gene signature early in the angiogenic process. This study expands the list of genes associated with the acquisition of a tip cell phenotype during endothelial cell sprout initiation.

NEDD9 Overexpression Causes Hyperproliferation of Luminal Cells and Cooperates with HER2 Oncogene in Tumor Initiation: A Novel Prognostic Marker in Breast Cancer

HER2 overexpression occurs in 10-20% of breast cancer patients. HER2+ tumors are characterized by an increase in Ki67, early relapse, and increased metastasis. Little is known about the factors influencing early stages of HER2- tumorigenesis and diagnostic markers. Previously, it was shown that the deletion of NEDD9 in mouse models of HER2 cancer interferes with tumor growth, but the role of NEDD9 upregulation is currently unexplored. We report that NEDD9 is overexpressed in a significant subset of HER2+ breast cancers and correlates with a limited response to anti-HER2 therapy. To investigate the mechanisms through which NEDD9 influences HER2-dependent tumorigenesis, we generated MMTV-Cre-NEDD9 transgenic mice. The analysis of mammary glands shows extensive ductal epithelium hyperplasia, increased branching, and terminal end bud expansion. The addition of oncogene Erbb2 (neu) leads to the earlier development of early hyperplastic benign lesions (~16 weeks), with a significantly shorter latency than the control mice. Similarly, NEDD9 upregulation in MCF10A-derived acini leads to hyperplasia-like DCIS. This phenotype is associated with activation of ERK1/2 and AURKA kinases, leading to an increased proliferation of luminal cells. These findings indicate that NEDD9 is setting permissive conditions for HER2-induced tumorigenesis, thus identifying this protein as a potential diagnostic marker for early detection.

Combined high NEDD9 expression and E-cadherin loss correlate with poor clinical outcome in gastric cancer

BACKGROUND AND AIM

Neural precursor cell expressed developmentally downregulated 9 (NEDD9) is a member of the Cas family. Previous studies have revealed that NEDD9 coordinates the focal adhesion kinase and Src signaling cascades that are involved in integrin-dependent adhesion and migration, invasion, cell apoptosis and life cycle, and survival, which may play a role in epithelial-mesenchymal transformation. The aim of this study was to analyze the expression of NEDD9 and E-cadherin in gastric cancer (GC) and evaluate their clinical significance.

METHODS

NEDD9 and E-cadherin expression was analyzed with immunohistochemistry using tissue microarray technique in 435 GC patients who underwent gastrectomy. The NEDD9 expression level was defined by the combination score, which was determined by multiplying the staining intensity score and the proportion score (≥5; NEDD9-high, <5; NEDD9-low). E-cadherin loss was defined as a total loss of staining. The clinicopathologic parameters, overall survival, and disease-free survival rates were analyzed according to the NEDD9 and E-cadherin expression status.

RESULTS

The combined NEDD9 and E-cadherin expression status correlated with lymphatic invasion (P = 0.001), vascular invasion (P = 0.020), and T stage (P = 0.001). Combined high NEDD9 expression and loss of E-cadherin expression status had a worse overall survival rate (P < 0.001) and served as a poor prognostic factor (Hazard ratio 2.49, 95% CI 1.25-5, P = 0.01).

CONCLUSIONS

Immunohistochemical staining for NEDD9 and E-cadherin may function as a candidate prognostic marker for gastric cancer in everyday practice, especially when applied in combination.

NEDD9 links anaplastic thyroid cancer stemness to chromosomal instability through integrated centrosome asymmetry and DNA sensing regulation

Stemness and chromosomal instability (CIN) are two common contributors to intratumor heterogeneity and therapy relapse in advanced cancer, but their interplays are poorly defined. Here, in anaplastic thyroid cancer (ATC), we show that ALDH+ stem-like cancer cells possess increased CIN-tolerance owing to transcriptional upregulation of the scaffolding protein NEDD9. Thyroid patient tissues and transcriptomic data reveals NEDD9/ALDH1A3 to be co-expressed and co-upregulated in ATC. Compared to bulk ALDH- cells, ALDH+ cells were highly efficient at propagating CIN due to their intrinsic tolerance of both centrosome amplification and micronuclei. ALDH+ cells mitigated the fitness-impairing effects of centrosome amplification by partially inactivating supernumerary centrosomes. Meanwhile, ALDH+ cells also mitigated cell death caused by micronuclei-mediated type 1 interferon secretion by suppressing the expression of the DNA-sensor protein STING. Both mechanisms of CIN-tolerance were lost upon RNAi-mediated NEDD9 silencing. Both in vitro and in vivo, NEDD9-depletion attenuated stemness, CIN, cell/tumor growth, while enhancing paclitaxel effectiveness. Collectively, these findings reveal that ATC progression can involve an ALDH1A3/NEDD9-regulated program linking their stemness to CIN-tolerance that could be leveraged for ATC treatment.

Susceptibility-Associated Genetic Variation in NEDD9 Contributes to Prostate Cancer Initiation and Progression

Although American men of European ancestry represent the largest population of patients with prostate cancer, men of African ancestry are disproportionately affected by prostate cancer, with higher prevalence and worse outcomes. These racial disparities in prostate cancer are due to multiple factors, but variations in genomic susceptibility such as SNP may play an important role in determining cancer aggressiveness and treatment outcome. Using public databases, we have identified a prostate cancer susceptibility SNP at an intronic enhancer of the neural precursor expressed, developmentally downregulated 9 (NEDD9) gene, which is strongly associated with increased risk of patients with African ancestry. This genetic variation increased expression of NEDD9 by modulating the chromatin binding of certain transcription factors, including ERG and NANOG. Moreover, NEDD9 displayed oncogenic activity in prostate cancer cells, promoting prostate cancer tumor growth and metastasis in vitro and in vivo. Together, our study provides novel insights into the genetic mechanisms driving prostate cancer racial disparities. SIGNIFICANCE: A prostate cancer susceptibility genetic variation in NEDD9, which is strongly associated with the increased risk of patients with African ancestry, increases NEDD9 expression and promotes initiation and progression of prostate cancer.See related commentary by Mavura and Huang, p. 3764.

Identification of prognostic genes in uveal melanoma microenvironment

Background

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Many previous studies have demonstrated that the infiltrating of immune and stromal cells in the tumor microenvironment contributes significantly to prognosis.

Methods

Dataset TCGA-UVM, download from TCGA portal, was taken as the training cohort, and GSE22138, obtained from GEO database, was set as the validation cohort. ESTIMATE algorithm was applied to find intersection differentially expressed genes (DEGs) among tumor microenvironment. Kaplan-Meier analysis and univariate Cox regression model were performed on intersection DEGs to initial screen for potential prognostic genes. Then these genes entered into the validation cohort for validation using the same methods as that in the training cohort. Moreover, we conducted correlation analyses between the genes obtained in the validation cohort and the status of chromosome 3, chromosome 8q, and tumor metastasis to get prognosis genes. At last, the immune infiltration analysis was performed between the prognostic genes and 6 main kinds of tumor-infiltrating immune cells (TICs) for understanding the role of the genes in the tumor microenvironment.

Results

959 intersection DEGs were found in the UM microenvironment. Kaplan-Meier and Cox analysis was then performed in the training and validation cohorts on these DEGs, and 52 genes were identified with potential prognostic value. After comparing the 52 genes to chromosome 3, chromosome 8q, and metastasis, we obtained 21 genes as the prognostic genes. The immune infiltration analysis showed that Neutrophil had the potential prognostic ability, and almost every prognostic gene we had identified was correlated with abundances of Neutrophil and CD8+ T Cell.

Conclusions

Identifying 21 prognosis genes (SERPINB9, EDNRB, RAPGEF3, HFE, RNF43, ZNF415, IL12RB2, MTUS1, NEDD9, ZNF667, AZGP1, WARS, GEM, RAB31, CALHM2, CA12, MYEOV, CELF2, SLCO5A1, ISM1, and PAPSS2) could accurately identify patients' prognosis and had close interactions with Neutrophil in the tumor environment, which may provide UM patients with personalized prognosis prediction and new treatment insights.

Vitamin D modulates E-cadherin turnover by regulating TGF-β and Wnt signalings during EMT-mediated myofibroblast differentiation in A459 cells

Vitamin D (VitD) has an anti-fibrotic effect on fibrotic lungs. It reduces epithelial-mesenchymal transition (EMT) on tumors. We aimed to investigate target proteins of VitD for the regression of EMT-mediated myofibroblast differentiation. A group of A549 cells were treated with 5 % cigarette smoke extract (CSE) and 5 %CSE + TGF-β (5 ng/ml) to induce EMT. The others were treated with 50 nM VitD 30 min before %5CSE and TGF-β treatments. All cells were collected at 24, 48 and 72 h following 5 %CSE and TGF-β administrations. The expression of p120ctn and NEDD9 proteins acted on E-cadherin turnover in addition to activations of TGF-β and Wnt pathways were examined in these cells and fibrotic human lungs. CSE and TGF-β induced EMT by reducing E-cadherin, p-VDR, SMAD7 and DKK1, increasing α-SMA, p120ctn, Kaiso, NEDD9 and stimulating TGF-β and Wnt/β-catenin signalings in A549 cells. VitD administration reversed these alterations and regressed EMT. Co-immunoprecipitation analysis revealed p-VDR interaction with β-catenin and Kaiso in fibrotic and non-fibrotic human lungs. VitD pre-treatments reduced TGF-β and Wnt/β-catenin signalings by increasing p-VDR, protected from E-cadherin degradation and led to the regression of EMT in A549 cells treated with CSE and TGF-β. Finally, VitD supplementation combined with anti-fibrotic therapeutics can be suggested for treatment of pulmonary fibrosis, which may be developed by smoking, in cases of VitD deficiency.

Inhibition of p62/SQSTM1 sensitizes small-cell lung cancer cells to cisplatin-induced cytotoxicity by targeting NEDD9 expression

Drug resistance is the leading cause for rapid progression and relapse in small-cell lung cancer (SCLC) patients. Thus overcoming drug resistance still remains to be urgently resolved during SCLC treatment. Here, we found p62/SQSTM1 was enriched in SCLC spheroids, a subpopulation possessing cancer stem-like properties, which is responsible for cancer relapse and metastasis. Subsequent functional assays in vitro showed that short hairpin RNA (shRNA)-mediated p62 knockdown increased sensitivity of SCLC cell lines to cisplatin (DDP), whereas lentivirus-mediated p62 ectopic overexpression diminished DDP-induced cytotoxicity in both NCI-H446 and NCI-H1688 cell lines. Moreover, ectopic p62 overexpression promoted DDP resistance of NCI-H446 cells-derived tumor xenografts in immunodeficient mice in vivo, as indicated by accelerated tumor growth rate and reduced fluorescent activity of cleaved caspase-3. Gene expression profiling analysis revealed that p62 was positively correlated with neuronal precursor cell-expressed, developmentally downregulated gene 9 (NEDD9) expression level. Consistently, NEDD9 messenger RNA (mRNA) level was decreased upon p62 suppression by small interfering RNA (siRNA) and increased with p62 transient overexpression in SCLC cell lines, suggesting that p62 positively regulated NEDD9 mRNA. Depletion of NEDD9 by siRNA, to a large extent, reversed p62-overexpressed SCLC cells to DDP-induced cytotoxicity, implying NEDD9 might act as a downstream target which was in charge of p62-mediated DDP resistance. Taken together, our findings uncovered a previously unknown role of p62 in the regulation of SCLC drug resistance, assigning p62 as an attractive target for SCLC treatment.

Identification of the differential expression of genes and upstream microRNAs in small cell lung cancer compared with normal lung based on bioinformatics analysis

Small cell lung cancer (SCLC) is one of the most lethal cancer, mainly attributing to its high tendency to metastasis. Mounting evidence has demonstrated that genes and microRNAs (miRNAs) are related to human cancer onset and progression including invasion and metastasis.An eligible gene dataset and an eligible miRNA dataset were downloaded from the Gene Expression Omnibus (GEO) database based our screening criteria. Differentially expressed genes (DE-genes) or DE-miRNAs for each dataset obtained by the R software package. The potential target genes of the top 10 DE-miRNAs were predicted by multiple databases. For annotation, visualization and integrated discovery, Metascape 3.0 was introduced to perform enrichment analysis for the DE-genes and the predicted target genes of the selected top 10 DE-miRNAs, including Pathway and Process Enrichment Analysis or protein-protein interaction enrichment analysis. The intersection of predicted target genes and DE-genes was taken as the final DE-genes. Then apply the predicted miRNAs-targets relationship of top 10 DE-miRNAs to the final DE-genes to gain more convinced DE-miRNAs, DE-genes and their one to one relationship.GSE19945 (miRNA microarray) and GSE40275 (gene microarray) datasets were selected and downloaded. 56 DE-miRNAs and 861 DE-genes were discovered. 297 miRNAs-targets relationships (284 unique genes) were predicted as the target of top 10 upregulating DE-miRNAs. 245 miRNAs-targets relationships (238 unique genes) were identified as the target of top 10 downregulating DE-miRNAs. The key results of enrichment analysis include protein kinase B signaling, transmembrane receptor protein tyrosine kinase signaling pathway, negative regulation of cell differentiation, response to growth factor, cellular response to lipid, muscle structure development, response to growth factor, signaling by Receptor Tyrosine Kinases, epithelial cell migration, cellular response to organic cyclic compound, Cell Cycle (Mitotic), DNA conformation change, cell division, DNA replication, cell cycle phase transition, blood vessel development, inflammatory response, Staphylococcus aureus infection, leukocyte migration, and myeloid leukocyte activation. Differential expression of genes-upstream miRNAs (RBMS3-hsa-miR-7-5p, NEDD9-hsa-miR-18a-5p, CRIM1-hsa-miR-18a-5p, TGFBR2-hsa-miR-9-5p, MYO1C-hsa-miR-9-5p, KLF4-hsa-miR-7-5p, EMP2-hsa-miR-1290, TMEM2-hsa-miR-18a-5p, CTGF-hsa-miR-18a-5p, TNFAIP3-hsa-miR-18a-5p, THBS1-hsa-miR-182-5p, KPNA2-hsa-miR-144-3p, GPR137C-hsa-miR-1-3p, GRIK3-hsa-miR-144-3p, and MTHFD2-hsa-miR-30a-3p) were identified in SCLC.RBMS3, NEDD9, CRIM1, KPNA2, GPR137C, GRIK3, hsa-miR-7-5p, hsa-miR-18a-5p, hsa-miR-144-3p, hsa-miR-1-3p along with the pathways included protein kinase B signaling, muscle structure development, Cell Cycle (Mitotic) and blood vessel development may gain a high chance to play a key role in the prognosis of SCLC, but more studies should be conducted to reveal it more clearly.

Long noncoding RNA linc00467 plays an oncogenic role in hepatocellular carcinoma by regulating the miR-18a-5p/NEDD9 axis

Increasing evidence has shown that numerous long noncoding RNAs (lncRNAs) play critical roles in tumorigenesis. Herein, we investigated the biological role of lncRNA linc00467 in the cancer biology of hepatocellular carcinoma (HCC). We observed that linc00467 was upregulated in HCC tissues and cells. Silencing of linc00467 using small interfering RNA interference significantly inhibited the growth and motility of HCC cells, and increased cell apoptosis through regulating the Bcl-2/Bax axis and the caspase cascade, suggesting that linc00467 exerted oncogenic functions in the progression of HCC. Moreover, we found that linc00467 could target miR-18a-5p, and NEDD9 was a target for miR-18a-5p in HCC cells. Furthermore, either the miR-18a-5p inhibitor or upregulation of NEDD9 could recover the inhibitory effects caused by silencing of linc00467. In conclusion, our data highlighted the oncogenic role of linc00467 in HCC progression by regulating the miR-18a-5p/NEDD9 axis.

Bee Venom Suppresses EGF-Induced Epithelial-Mesenchymal Transition and Tumor Invasion in Lung Cancer Cells

Bee venom of Apis mellifera is a traditional medicine in Asia. It has been used with promoting results for the treatment of pain, rheumatoid, and cancer disease. The purpose of this study was to investigate the effects of bee venom on epidermal growth factor (EGF)-induced epithelial-mesenchymal transition (EMT) in non-small cell lung cancer (NSCLC) and determine possible signaling pathway affected in EGF-induced EMT in A549 cells. Bee venom inhibited EGF-induced F-actin reorganization and cell invasion, and suppressed EGF-induced EMT, processes associated with tumor metastasis in NSCLC. Bee venom enhanced the upregulation of E-cadherin and the downregulation of vimentin and inhibited EGF-induced ERK, JNK, FAK, and mTOR phosphorylation in A549 cells. However, the inhibition of JNK phosphorylation by bee venom was not related to the inhibitory effects of EMT. Furthermore, we found that bee venom suppressed the EMT-related transcription factors ZEB2 and Slug by blocking EGF-induced ERK, FAK and mTOR phosphorylation. Bee venom inhibits EGF-induced EMT by blocking the phosphorylation of ERK, FAK, and mTOR, resulting in the suppression of ZEB2 and Slug. These data suggest bee venom as a potential antimetastatic agent for NSCLC.

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.

NETO2 promotes pancreatic cancer cell proliferation, invasion and migration via activation of the STAT3 signaling pathway

Purpose: The biological functions of neuropilin and tolloid-like 2 (NETO2) in the progression of pancreatic cancer remained unexplored. We aimed to investigate the biological roles and underlying molecular mechanisms of NETO2 in pancreatic cancer.

Materials and methods: Thirty paired pancreatic tumor tissue samples and corresponding nontumor tissues were obtained from 30 pancreatic cancer patients who did not receive preoperative chemotherapy or radiotherapy. The changes in multiple cellular functions associated with tumor progression were assessed after NETO2 knockdown/overexpression in pancreatic cancer cell lines. Additionally, a mouse-xenograft model was developed to verify the in vitro results.

Results:NETO2 was upregulated in pancreatic tumor tissues. Elevated expression of NETO2 was not only associated with an advanced tumor stage, but was also a prediction of poor prognosis for pancreatic cancer patients. Knockdown of NETO2 in pancreatic cancer cell lines arrested the cell cycle and inhibited cell proliferation, colony formation, invasion, and migration; in contrast, overexpression of NETO2 had an opposite effect on all of these parameters. A STAT3 specific inhibitor, cryptotanshinone, reversed the tumor-promoting effects induced by NETO2 overexpression in pancreatic cancer. Western blot analysis showed that invasion and migration were closely related to epithelial–mesenchymal transition, and that the STAT3 signaling pathway was involved in NETO2-mediated oncogenic transformation in pancreatic cancer cells. Furthermore, NETO2 knockdown significantly inhibited the growth of pancreatic tumor xenografts in nude mice.

Conclusion:NETO2 has an important role in the progression and metastasis of pancreatic cancer and could serve as a novel candidate for targeted therapy of pancreatic cancer.

NEDD9 overexpression predicts poor prognosis in solid cancers: a meta-analysis

Background: The oncogenicity of neural precursor cell-expressed developmentally down-regulated 9 (NEDD9) has been demonstrated in multiple cancer types. However, the prognostic value of NEDD9 in some solid cancers remains controversial. Thus, this meta-analysis was conducted to evaluate the relationship between NEDD9 expression survival rates in solid tumors.

Method: Our meta-analysis included studies searched from various search engines with specific inclusion criteria and exclusion criteria. Combined HRs for overall survival (OS) and disease-free survival (DFS) or progression-free survival (PFS) or recurrence-free survival (RFS) or cancer-specific survival (CSS) were assessed using fixed-effects and random-effects models. The source of heterogeneity was identified by subgroup analysis. Additionally, publication bias was assessed using funnel plot and Egger’s regression asymmetry test.

Result: Eighteen studies with a total of 2,476 patients were retrieved for analysis. Pooled HRs and 95% CIs were calculated. Both OS (HR=1.82; 95% CI: 1.43–2.31) and DFS/PFS/RFS/CSS (HR=2.54; 95% CI: 1.93–3.33) indicated that NEDD9 overexpression is associated with poor OS in cancer patients with solid tumors.

Conclusion: NEDD9 overexpression might be a potential marker to predict prognosis in solid cancer patients.

NEDD9 Facilitates Hypoxia-Induced Gastric Cancer Cell Migration via MICAL1 Related Rac1 Activation

Aims and Hypothesis: NEDD9 is highly expressed in gastric cancer and has a significant involvement in its pathogenesis. However, the mechanism behind hypoxia-promoted cancer cell migration and its regulation because of NEDD9 is still unknown. The aim of this study is to investigate the involvement of NEDD9 in gastric cancer cell migration under hypoxia and explore the underlying potential molecular mechanisms.

Vimentin and Non-Muscle Myosin IIA are Members of the Neural Precursor Cell Expressed Developmentally Down-Regulated 9 (NEDD9) Interactome in Head and Neck Squamous Cell Carcinoma Cells

Here we demonstrate an interaction between neural precursor cell expressed, developmentally-downregulated 9 (NEDD9) and the cytoskeletal proteins vimentin and non-muscle myosin IIA (NMIIA), based on co-immunoprecipitation and mass spectrometric sequence identification. Vimentin was constitutively phosphorylated at Ser56 but vimentin associated with NEDD9-was not phosphorylated at Ser56. In contrast, NMIIA bound to NEDD9 was phosphorylated on S1943 consistent with its function in invasion and secretion. Treatment of cells with the vimentin-targeting steroidal lactone withaferin A had no effect on vimentin turnover as previously reported, instead causing NEDD9 cleavage and cell death. The NMIIA-selective inhibitor blebbistatin induced cells to form long extensions and attenuated secretion of matrix metalloproteinases (MMPs) 2 and 9. While the site of vimentin interaction on NEDD9 was not defined, NMIIA was found to interact with NEDD9 at its substrate domain. NEDD9 interactions with vimentin and NMIIA are consistent with these proteins having roles in MMP secretion and cell invasion. These findings suggest that a better understanding of NEDD9 signaling is likely to reveal novel therapeutic targets for the prevention of invasion and metastasis.

Knockdown of SNHG12 suppresses tumor metastasis and epithelial-mesenchymal transition via the Slug/ZEB2 signaling pathway by targeting miR-218 in NSCLC

Non-small cell lung cancer (NSCLC) is a type of lung cancer which has a high mortality and low survival rate. Previous studies have revealed that long non-coding RNAs participate in tumorigenesis and metastasis in NSCLC. In the present study, the function of small nucleolar RNA host gene 12 (SNHG12) was investigated in NSCLC. Using reverse transcription-quantitative polymerase chain reaction analysis, it was identified that SNHG12 was significantly overexpressed in NSCLC specimens. Furthermore, overexpression of SNHG12 was identified to be associated with tumor progression and poor overall survival rates. Knockdown of SNHG12 in NSCLC cells could effectively induce cell apoptosis and suppress cell viability, proliferation, migration and invasion via inhibition of the epithelial-mesenchymal transition process. Furthermore, a direct interaction between microRNA (miR)-218 and the binding site of SNHG12 was identified. SNHG12 acted as an endogenous sponge for miR-218. Knockdown of SNHG12 upregulated the expression level of miR-218 as well as downregulating the Slug/zinc finger E-box-binding homeobox 2 EMT signaling pathway, and thus inhibited cell migration and invasion. Therefore, SNHG12 may serve as a key biomarker and a potential therapeutic target for the treatment of NSCLC.

Epithelial‑mesenchymal transition phenotype of circulating tumor cells is associated with distant metastasis in patients with NSCLC

Circulating tumor cells (CTCs) are closely associated with cancer metastasis in preclinical models and patients with cancer. However, to the best of the authors knowledge, it remains unknown which type of CTCs may serve the key role in cancer metastasis. The present study investigated the association between the epithelial‑mesenchymal transition (EMT) phenotype of CTCs from the peripheral blood and distant metastasis in patients with non‑small cell lung cancer (NSCLC). Expression of EMT markers in CTCs from a cohort of patients was detected using Canpatrol™ CTC assays. A total of 110 patients (85 patients with NSCLC and 25 patients with benign diseases) were recruited. Among the 110 patients, 88 (80.0%) were characterized as CTC positive with EMT markers. Receiver operating characteristic curves revealed that E+/M+ CTCs exhibited the highest area under the curve (AUC) value of 0.876 [95% confidence interval (CI), 0.805‑0.948; P<0.001) in distinguishing between patients with NSCLC and benign pulmonary diseases, and M+ CTCs had the highest AUC value of 0.723 (95% CI, 0.612‑0.833; P<0.001) in differentiating patients with NSCLC with distant metastasis from those with non‑distant metastasis. The results indicate the potential predictive value of distant metastasis of the EMT phenotype of CTCs in the peripheral blood of patients with NSCLC.

Regulatory mechanisms of miR-145 expression and the importance of its function in cancer metastasis

MicroRNAs are post-transcriptional mediators of gene expression and regulation, which play influential roles in tumorigenesis and cancer metastasis. The expression of tumor suppressor miR-145 is reduced in various cancer cell lines, containing both solid tumors and blood malignancies. However, the responsible mechanisms of its down-regulation are a complicated network. miR-145 is potentially able to inhbit tumor cell metastasis by targeting of multiple oncogenes, including MUC1, FSCN1, Vimentin, Cadherin, Fibronectin, Metadherin, GOLM1, ARF6, SMAD3, MMP11, Snail1, ZEB1/2, HIF-1α and Rock-1. This distinctive role of miR-145 in the regulation of metastasis-related gene expression may introduce miR-145 as an ideal candidate for controlling of cancer metastasis by miRNA replacement therapy. The present review aims to discuss the current understanding of the different aspects of molecular mechanisms of miR-145 regulation as well as its role in r metastasis regulation.

HDAC3-mediated silencing of miR-451 decreases chemosensitivity of patients with metastatic castration-resistant prostate cancer by targeting NEDD9

Background:

Treatment of metastatic castration-resistant prostate cancer (mCRPC) with docetaxel often fails due to the emergence of chemoresistance. Thus, restoring chemosensitivity to docetaxel-based therapies remains a challenge in mCRPC treatment.

Methods:

microRNA (miR)-451 expression was measured in docetaxel-treated prostate cancer cells and tumor tissues by quantitative reverse-transcription polymerase chain reaction . Cell-counting kit 8 assay was performed to determine docetaxel chemoresistance. Neural-precursor-cell-expressed developmentally downregulated protein 9 (NEDD9) was identified as a novel target of miR-451 by dual-luciferase reporter system. Chromatin immunoprecipitation and co-immunoprecipitation assay were performed to confirm that histone deacetylase 3 (HDAC3)/Sp1 (a highly evolutionarily conserved transcription factor) interacted with the Sp1 binding sites in miR-451 promoter.

Results:

miR-451 was found to be silenced in docetaxel-treated prostate cancer cells and mCRPC tissues. Low miR-451 expression was closely associated with a high Gleason score, high Eastern Cooperative Oncology Group performance status score, visceral metastasis and poor prognosis. Low expression of miR-451 was significantly correlated with short progression-free survival (PFS) and overall survival (OS) according to Kaplan–Meier analysis, and miR-451 was determined to be an independent poor prognostic factor for PFS and OS in mCRPC patients by univariate and multivariate Cox regression analyses. NEDD9 was identified as a new and functional target of miR-451. Restoration of NEDD9 partially reversed the effects of miR-451 on enhancing chemosensitivity of prostate cancer cells. HDAC3 was confirmed to be involved in silencing of miR-451 expression in prostate cancer cells.

Conclusions:

The current data revealed a new HDAC3/Sp1/miR-451/NEDD9 signaling axis that regulates the chemosensitivity of prostate cancer cells and represents a novel therapeutic target for chemosensitizing mCRPC.

NEDD9 stimulated MMP9 secretion is required for invadopodia formation in oral squamous cell carcinoma

Neural precursor cell expressed developmentally downregulated 9 (NEDD9) is a component of the metastatic signatures of melanoma, breast cancer, glioblastoma, lung cancer and head and neck squamous cell carcinoma (HNSCC). Here we tested the efficacy of NEDD9's domains in stimulating matrix metalloproteinase (MMP) secretion and invadopodia formation in cells stably expressing various NEDD9 mutants. Replacement of the 13 YxxP motif substrate domain (SD) tyrosines and the C-terminal Y629 with phenylalanines (F14NEDD9) eliminated tyrosine phosphorylation, MMP9 secretion and loss of invadopodia formation. Mutation of the N-terminal SH3 domain Y12 to glutamic acid (Y12ENEDD9) or phenylalanine (Y12FNEDD9) reduced MMP9 secretion and inhibited invadopodia formation. SH3 domain deletion (∆SH3NEDD9) resulted in the loss of MMP9 secretion and a lack of invadopodia formation. The SH3–SD domain (SSNEDD9) construct exhibited tyrosine phosphorylation and stimulated MMP9 secretion, as did ∆CTNEDD9 which lacked the C-terminus (∆C-terminal; ∆CT). E13NEDD9 expression blocked MMP9 secretion and invadopodia formation. MICAL1 (molecule interacting with Cas-L1) silencing with a short hairpin RNA reduced MMP9 secretion, vimentin and E-cadherin levels while increasing N-cadherin and Rab6 levels, consistent with reduced invasive behavior. These findings indicate that NEDD9 SD phosphorylation and SH3 domain interactions are necessary for increasing MMP9 secretion and invadopodia formation.

MicroRNA-30a-5p inhibits gallbladder cancer cell proliferation, migration and metastasis by targeting E2F7

Gallbladder carcinoma (GBC), the most common malignant tumour of the bile duct, is highly aggressive and has a poor prognosis. MicroRNA-30a-5p (miR-30a-5p) is an important tumour suppressor that participates in many aspects of carcinogenesis and cancer development. However, the role of miR-30a-5p in GBC development remains to be determined, as do the mechanisms underlying its effects in GBC. Using samples collected from 42 subjects with gallbladder carcinoma (GBC), we showed decreased miR-30a-5p expression in the primary lesions vs. non-tumour adjacent tissues (NATs). Decreased miR-30a-5p was associated with shorter disease-free survival (DFS) and overall survival (OS). Inhibiting miR-30a-5p expression in 2 representative GBC cell lines (GBC-SD and NOZ) increased cell proliferation, migration, invasiveness, as well as β-catenin nuclear translocation, vice versa. In nude mice, NOZ cells transfected with miR-30a-5p mimics grew slower (vs. miR-NC) upon subcutaneous inoculation, and had lower rate of hepatic metastasis upon spleen inoculation. Dual luciferase assay confirmed that E2F transcription factor 7 (E2F7) was a direct target of miR-30a-5p and antagonized the effects induced by miR-30a-5p downregulation in GBC cells. MiR-30a-5p attenuates the EMT and metastasis in GBC cells by targeting E2F7, suggesting miR-30a-5p is a tumour suppressor that may serve as a novel potential prognostic biomarker or molecular therapeutic target for GBC.

Overexpression of NEDD9 promotes cell invasion and metastasis in hepatocellular carcinoma

Neural precursor cell expressed, developmentally downregulated 9 (NEDD9), is a focal adhesion scaffold protein which has been associated with metastasis in several cancers. Recent study found that NEDD9 expression was upregulated in HCC. However, the precise function of NEDD9 in HCC is still unclear. In the present study, we demonstrated that high NEDD9 expression was associated with the invasiveness of HCC in clinical samples. Moreover, by gain-and-loss function studies, we revealed that silencing of NEDD9 expression inhibited cancer cells proliferation, migration and invasion, while upregulated expression of NEDD9 promoted invasion and metastasis of HCC cells in vitro and in vivo. Further studies revealed that NEDD9 inversely regulated E-cadherin in HCC cells and HCC tissues, which indicated that NEDD9 might promotes the invasion and metastasis of HCC cells through the downregulation of E-cadherin, possibly by inducing EMT. On the whole, our findings thus indicate that NEDD9 may serve as a metastasis-promoting gene and potential therapeutic target for the treatment of hepatocellular carcinoma.

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.

miR-768-3p is involved in the proliferation, invasion and migration of non-small cell lung carcinomas

Altered microRNA expression has been found to be a common feature of several cancers, including lung carcinomas. However, the possible roles of miR-768-3p in the pathological changes of lung carcinomas are still unknown. The aim of the present study was to investigate the expression and possible effects of miR-768-3p in human non-small cell lung carcinomas (NSCLC). Eighty-three NSCLC patients attending the clinic of Kunming Hospital were invited to participate in the study. Their tumor samples were obtained for qRT-PCR analysis. Human NSCLC cell lines, A549 and HCC4006, were employed and transfected with either miR-768-3p mimics or miR-768-3p antagomir. Following transfection, the in vitro and in vivo proliferation, apoptosis fractions, migration and invasion of NSCLC cells were evaluated. The data revealed that: i) upregulated miR-768-3p in tumors were associated with the clinicopathological features of NSCLC patients; ii) inhibiting miR-768-3p function by miR-768-3p antagomir induced distinctly apoptosis and Fas/FasL expressional alteration of NSCLC cells; iii) miR-768-3p antagomir transduction also decreased the viability, migration and invasion, as well as MMP-2 and MMP-9 activities in A549 and HCC4006 cells; and iv) miR-768-3p antagomir transfection also inhibited the growth and proliferation of NSCLC xenografts in nude mice. The present results suggested that abnormal elevated miR-768-3p in NSCLC tumors and cell lines played important roles in NSCLC carcinogenic progression, and the targeting of miR-768-3p might be a potential therapeutic strategy for the treatment of NSCLC.

Baicalein inhibits pancreatic cancer cell proliferation and invasion via suppression of NEDD9 expression and its downstream Akt and ERK signaling pathways

Baicalein, a flavone ingredient of Scutellaria baicalensis Georgi, is a promising anti-cancer agent. However, its potential anti-pancreatic cancer effects and the underlying mechanisms are still unclear. In this study, we showed that Baicalein not only induced apoptosis, but also suppressed proliferation, migration and invasion of two pancreatic cancer cell lines BxPC-3 and PANC-1 in a dose- and time-dependent manner. Notably, Baicalein exhibited low toxicity to normal human liver or kidney cells. We further discovered that Baicalein suppressed BxPC-3 and PANC-1 cell proliferation and invasion through targeting the expression of NEDD9, a Cas scaffolding protein, to decrease Akt and ERK activities. Especially, Baicalein decreased Akt phosphorylation at T-308 via lowering NEDD9-dependent PDK1 expression. Overexpression of NEDD9 effectively rescued proliferation and invasion of BxPC-3 and PANC-1 cells dampened by Baicalein. Taken together, our findings suggest that Baicalein is a potent remedy applied to pancreatic cancer treatment in the future.

Downregulation of miR-218 contributes to epithelial-mesenchymal transition and tumor metastasis in lung cancer by targeting Slug/ZEB2 signaling

Epithelial–mesenchymal transition (EMT) has been recognized as a key element of cell migration and invasion in lung cancer; however, the underlying mechanisms are not fully elucidated. Recently, emerging evidence suggest that miRNAs have crucial roles in control of EMT and EMT-associated traits such as migration, invasion and chemoresistance. Here, we found that miR-218 expression levels were significantly downregulated in lung cancer tissues compared with adjacent non-cancerous tissues, and the levels of miR-218 were significantly associated with histological grades and lymph node metastasis. Overexpression of miR-218 inhibited cell migration and invasion as well as the EMT process. Of particular importance, miR-218 was involved in the metastatic process of lung cancer cells in vivo by suppressing local invasion and distant colonization. We identified Slug and ZEB2 as direct functional targets of miR-218. Inverse correlations were observed between miR-218 levels and Slug/ZEB2 levels in cancer tissue samples. In addition, overexpression of miR-218 in H1299 increased chemosensitivity of cells to cisplatin treatment through suppression of Slug and ZEB2. These findings highlight an important role of miR-218 in the regulation of EMT-related traits and metastasis of lung cancer in part by modulation of Slug/ZEB2 signaling, and provide a potential therapeutic strategy by targeting miR-218 in NSCLC.

Preliminary results of a non-invasive method to measure tumor size and distribution in vivo

Molecular imaging of reporter gene expression in cancer cells can provide rapid, sensitive and non-invasive monitoring of tumor behavior. The aim of the present study was to establish a non-invasive method to measure tumor size and distribution in vivo. Briefly, H-Ras-transformed cells were stably transfected with a plasmid containing the luciferase gene (Luc), designated as Ras/Luc. Ras/Luc cells were injected into the back or tail vein of nude BALB/cAnN-Foxn1nu/CrlNarl mice (age, 6-8 weeks). Mice were subsequently administered D-luciferin via intra-peritoneal injection, prior to image acquisition. Photons emitted from the mice were detected via an imaging system. Tumor size and distribution in vivo were quantified as photons/second. Andrographolide has demonstrated radiosensitization in previous in vitro and in vivo studies. In the present study, the potential effects of andrographolide cancer metastasis were investigated further, using an imaging system. Preliminary results of andrographolide combined with radiation indicated the inhibition of cancer metastasis. The present mechanistic study of andrographolide-mediated effects demonstrated that activated extracellular signal regulated kinase protein and H₂O₂ production levels were significantly increased by andrographolide. In summary, the present study established a non-invasive method to measure tumor size and distribution in vivo and indicated that andrographolide may be a potential therapeutic strategy in cancer therapy.

miR-338 inhibits the metastasis of lung cancer by targeting integrin β3

miR-338 as an intronic miRNA from apoptosis-associated tyrosine kinase (AATK) is involved in tumor proliferation and apoptosis, but its function and regulatory mechanism in lung cancer is still obscure. In the present study, we found that miR-338 was strikingly downregulated in 115 lung cancer tissues and 5 lung cancer cell lines. Besides, low level of miR-338 was associated with tumor emboli, TNM stage, tumor recurrence and poor survival. Regaining the expression of miR-338 in lung cancer cell lines significantly impaired cellular adhesion, migration, invasion and lung tumor formation in nude mice. Furthermore, we also identified a metastasis related protein, integrin β3 (ITGB3), as a novel target gene of miR-338. Our results reveal a new regulatory mechanism of miR-338 which may help us better understand the metastasis of lung cancer.

High expression of HEF1 predicts a poorer prognosis of hepatocellular carcinoma: A retrospective study

Human enhancer of filamentation 1 (HEF1), a scaffold protein, is highly expressed in a variety of cancer types and is involved cancer cell growth, migration and invasion. The prognostic value of HEF1 in hepatocellular carcinoma (HCC) remains to be elucidated. The aim of the present study was to assess the association between the expression of HEF1, the clinical/pathological parameters and survival in HCC. In the present study, immunohistochemistry was performed to investigate the protein expression of HEF1 in 123 hepatocellular carcinoma tissues and their adjacent normal liver tissues. Spearman's rank correlation, Kaplan-Meier plots and Cox regression model were used to analyze the data. Overexpression of HEF1 protein was observed in HCC tissue when compared with their adjacent non-malignant liver tissue. High expression of HEF1 correlated with higher advanced tumor, node, metastasis (TNM) stage and vascular invasion (P<0.05). In univariate and multivariate analysis, the expression of HEF1 was identified as an independent prognostic factor in the 123 patients with HCC. In subgroup analysis, high expression of HEF1 correlated with a poorer prognosis in advanced (TNM III+IV) stages (P<0.05). These findings demonstrated the potential value of detecting the expression of HEF1 by immunohistochemistry as a prognostic biomarker and therapeutic target for patients with HCC.

Recursive Random Lasso (RRLasso) for Identifying Anti-Cancer Drug Targets

Uncovering driver genes is crucial for understanding heterogeneity in cancer. L1-type regularization approaches have been widely used for uncovering cancer driver genes based on genome-scale data. Although the existing methods have been widely applied in the field of bioinformatics, they possess several drawbacks: subset size limitations, erroneous estimation results, multicollinearity, and heavy time consumption. We introduce a novel statistical strategy, called a Recursive Random Lasso (RRLasso), for high dimensional genomic data analysis and investigation of driver genes. For time-effective analysis, we consider a recursive bootstrap procedure in line with the random lasso. Furthermore, we introduce a parametric statistical test for driver gene selection based on bootstrap regression modeling results. The proposed RRLasso is not only rapid but performs well for high dimensional genomic data analysis. Monte Carlo simulations and analysis of the "Sanger Genomics of Drug Sensitivity in Cancer dataset from the Cancer Genome Project" show that the proposed RRLasso is an effective tool for high dimensional genomic data analysis. The proposed methods provide reliable and biologically relevant results for cancer driver gene selection.

Current mechanistic insights into the roles of matrix metalloproteinases in tumour invasion and metastasis

The purpose of this review is to highlight the recent mechanistic developments elucidating the role of matrix metalloproteinases (MMPs) in tumour invasion and metastasis. The ability of tumour cells to invade, migrate, and subsequently metastasize is a fundamental characteristic of cancer. Tumour invasion and metastasis are increasingly being characterized by the dynamic relationship between cancer cells and their microenvironment and developing a greater understanding of these basic pathological mechanisms is crucial. While MMPs have been strongly implicated in these processes as a result of extensive circumstantial evidence--for example, increased expression of individual MMPs in tumours and association of specific MMPs with prognosis--the underpinning mechanisms are only now being elucidated. Recent studies are now providing a mechanistic basis, highlighting and reinforcing the catalytic and non-catalytic roles of specific MMPs as key players in tumour invasion and metastasis.

VEGF signals induce trailblazer cell identity that drives neural crest migration

Embryonic neural crest cells travel in discrete streams to precise locations throughout the head and body. We previously showed that cranial neural crest cells respond chemotactically to vascular endothelial growth factor (VEGF) and that cells within the migratory front have distinct behaviors and gene expression. We proposed a cell-induced gradient model in which lead neural crest cells read out directional information from a chemoattractant profile and instruct trailers to follow. In this study, we show that migrating chick neural crest cells do not display distinct lead and trailer gene expression profiles in culture. However, exposure to VEGF in vitro results in the upregulation of a small subset of genes associated with an in vivo lead cell signature. Timed addition and removal of VEGF in culture reveals the changes in neural crest cell gene expression are rapid. A computational model incorporating an integrate-and-switch mechanism between cellular phenotypes predicts migration efficiency is influenced by the timescale of cell behavior switching. To test the model hypothesis that neural crest cellular phenotypes respond to changes in the VEGF chemoattractant profile, we presented ectopic sources of VEGF to the trailer neural crest cell subpopulation and show diverted cell trajectories and stream alterations consistent with model predictions. Gene profiling of trailer cells that diverted and encountered VEGF revealed upregulation of a subset of 'lead' genes. Injection of neuropilin1 (Np1)-Fc into the trailer subpopulation or electroporation of VEGF morpholino to reduce VEGF signaling failed to alter trailer neural crest cell trajectories, suggesting trailers do not require VEGF to maintain coordinated migration. These results indicate that VEGF is one of the signals that establishes lead cell identity and its chemoattractant profile is critical to neural crest cell migration.

Identification of a multi-cancer gene expression biomarker for cancer clinical outcomes using a network-based algorithm

Cancer types are commonly classified by histopathology and more recently through molecular characteristics such as gene expression, mutations, copy number variations, and epigenetic alterations. These molecular characterizations have led to the proposal of prognostic biomarkers for many cancer types. Nevertheless, most of these biomarkers have been proposed for a specific cancer type or even specific subtypes. Although more challenging, it is useful to identify biomarkers that can be applied for multiple types of cancer. Here, we have used a network-based exploration approach to identify a multi-cancer gene expression biomarker highly connected by ESR1, PRKACA, LRP1, JUN and SMAD2 that can be predictive of clinical outcome in 12 types of cancer from The Cancer Genome Atlas (TCGA) repository. The gene signature of this biomarker is highly supported by cancer literature, biological terms, and prognostic power in other cancer types. Additionally, the signature does not seem to be highly associated with specific mutations or copy number alterations. Comparisons with cancer-type specific and other multi-cancer biomarkers in TCGA and other datasets showed that the performance of the proposed multi-cancer biomarker is superior, making the proposed approach and multi-cancer biomarker potentially useful in research and clinical settings.

Preclinical and clinical studies of the NEDD9 scaffold protein in cancer and other diseases

Cancer progression requires a significant reprogramming of cellular signaling to support the essential tumor-specific processes that include hyperproliferation, invasion (for solid tumors) and survival of metastatic colonies. NEDD9 (also known as CasL and HEF1) encodes a multi-domain scaffolding protein that assembles signaling complexes regulating multiple cellular processes relevant to cancer. These include responsiveness to signals emanating from the T and B cell receptors, integrins, chemokine receptors, and receptor tyrosine kinases, as well as cytoplasmic oncogenes such as BCR-ABL and FAK- and SRC-family kinases. Downstream, NEDD9 regulation of partners including CRKL, WAVE, PI3K/AKT, ERK, E-cadherin, Aurora-A (AURKA), HDAC6, and others allow NEDD9 to influence functions as pleiotropic as migration, invasion, survival, ciliary resorption, and mitosis. In this review, we summarize a growing body of preclinical and clinical data that indicate that while NEDD9 is itself non-oncogenic, changes in expression of NEDD9 (most commonly elevation of expression) are common features of tumors, and directly impact tumor aggressiveness, metastasis, and response to at least some targeted agents inhibiting NEDD9-interacting proteins. These data strongly support the relevance of further development of NEDD9 as a biomarker for therapeutic resistance. Finally, we briefly discuss emerging evidence supporting involvement of NEDD9 in additional pathological conditions, including stroke and polycystic kidney disease.

Involvement of NEDD9 in the invasion and migration of gastric cancer

Recent studies have demonstrated that neural precursor cell expressed, developmentally downregulated 9 (NEDD9) is highly expressed in various tumor tissues and cell lines. However, research on the role of NEDD9 in gastric cancer (GC) is rare, and the potential mechanism in tumor progression has not yet been explored. In this study, we investigated the role and mechanism of NEDD9 in GC. The expression of NEDD9 in GC tissues and cell lines was measured by immunohistochemistry, qRT-PCR, and Western blot, respectively. Inhibiting NEDD9 expression was carried out by siRNA transfection, and upregulating of NEDD9 was via NEDD9 overexpression plasmid. The ability of proliferation, migration, and invasion was detected by MTT assay, scratch wound assay, and transwell assay, respectively. The expression of vimentin, E-cadherin, Zeb1, and Zeb2 was measured by Western blot and qRT-PCR. We found that NEDD9 expression was dramatically increased both in GC tissues and cell lines, and the expression was significantly related to GC development. Knockdown of NEDD9 in SGC-7901 strongly inhibited its malignant capacity in vitro. Meanwhile, upregulation of NEDD9 in GES-1 increased the malignant capacity. In addition, the expression of vimentin, Zeb1, and Zeb2 was positively correlated with NEDD9, while E-cadherin was opposite. Collectively, our findings suggest that NEDD9 acts as an oncogene and promotes GC metastasis via EMT.

Role for chondroitin sulfate glycosaminoglycan in NEDD9-mediated breast cancer cell growth

There are lines of evidence demonstrating that NEDD9 (Cas-L, HEF-1) plays a key role in the development, progression, and metastasis of breast cancer cells. We previously reported that NEDD9 plays a critical role for promoting migration and growth of MDA-MB-231. In order to further characterize the mechanisms of NEDD9-mediated cancer migration and growth, stable cells overexpressing NEDD9 were generated using HCC38 as a parental cell line which expresses low level of endogenous NEDD9. Microarray studies demonstrated that core proteins of CD44 and Serglycin were markedly upregulated in HCC38(NEDD9) cells compared to HCC38(Vector) cells, while those of Syndecan-1, Syndecan-2, and Versican were downregulated in HCC38(NEDD9). Importantly, enzymes generating chondroitin sulfate glycosaminoglycans (CS) such as CHST11, CHST15, and CSGALNACT1 were upregulated in HCC38(NEDD9) compared to HCC38(Vector). Immunofluorescence studies using specific antibody, GD3G7, confirmed the enhanced expression of CS-E subunit in HCC38(NEDD9). Immunoprecipitation and western blotting analysis demonstrated that CS-E was attached to CD44 core protein. We demonstrated that removing CS by chondroitinase ABC significantly inhibited anchorage-independent colony formation of HCC38(NEDD9) in methylcellulose. Importantly, the fact that GD3G7 significantly inhibited colony formation of HCC38(NEDD9) cells suggests that CS-E subunit plays a key role in this process. Furthermore, treatment of HCC38(NEDD9) cells with chondroitinase ABC or GD3G7 significantly inhibited mammosphere formation. Exogenous addition of CS-E enhanced colony formation and mammosphere formation of HCC38 parental and HCC38(Vector) cells. These results suggest that NEDD9 regulates the synthesis and expression of tumor associated glycocalyx structures including CS-E, which plays a key role in promoting and regulating breast cancer progression and metastasis and possibly stem cell phenotypes.

The NOTCH ligand JAGGED2 promotes pancreatic cancer metastasis independent of NOTCH signaling activation

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive and lethal disease with a high rate of metastasis. Numerous signaling events have been implicated in the molecular pathogenesis of this neoplasm. Aberrantly high expression of JAGGED2, one of the NOTCH ligands, often occurs in human PDAC. However, what role JAGGED2 plays in the disease development and whether JAGGED2 executes its function through activating NOTCH signaling remain to be determined. We report here that JAGGED2 plays a critical role in promoting PDAC metastasis in vitro and in vivo. Depletion of JAGGED2, but not its homolog JAGGED1, profoundly inhibited both migration and invasion without influencing cell proliferation. Furthermore, reconstitution of JAGGED2 expression rescued the migratory defect. Surprisingly, neither pharmacologic nor genetic inhibition of NOTCH downstream signaling resulted in obvious defect in metastasis. Instead, depletion of NOTCH1 expression per se gave rise to migratory defects similar to JAGGED2 ablation. Moreover, blockade of ligand-receptor interaction by a specific JAGGED2-Fc fusion protein dramatically inhibited PDAC cell migration, suggesting that tumor metastasis relies on physical interactions of JAGGED2-NOTCH1 but not Notch downstream signaling activation. Taken together, our data reveal a novel role of NOTCH in regulation of PDAC metastasis, and identify JAGGED2 as a critical mediator in this event. These findings also provide rationale for developing small molecules or biologic agents targeting JAGGED2 for therapeutic intervention.

Prometastatic NEDD9 Regulates Individual Cell Migration via Caveolin-1-Dependent Trafficking of Integrins

The dissemination of tumor cells relies on efficient cell adhesion and migration, which in turn depends upon endocytic trafficking of integrins. In the current work, it was found that depletion of the prometastatic protein, NEDD9, in breast cancer cells results in a significant decrease in individual cell migration due to impaired trafficking of ligand-bound integrins. NEDD9 deficiency does not affect the expression or internalization of integrins but heightens caveolae-dependent trafficking of ligand-bound integrins to early endosomes. Increase in mobility of ligand-bound integrins is concomitant with an increase in tyrosine phosphorylation of caveolin-1 (CAV1) and volume of CAV1-vesicles. NEDD9 directly binds to CAV1 and colocalizes within CAV1 vesicles. In the absence of NEDD9, the trafficking of ligand-bound integrins from early to late endosomes is impaired, resulting in a significant decrease in degradation of ligand-integrin complexes and an increase in recycling of ligand-bound integrins from early endosomes back to the plasma membrane without ligand disengagement, thus leading to low adhesion and migration. Reexpression of NEDD9 or decrease in the amount of active, tyrosine 14 phosphorylated (Tyr14) CAV1 in NEDD9-depleted cells rescues the integrin trafficking deficiency and restores cellular adhesion and migration capacity. Collectively, these findings indicate that NEDD9 orchestrates trafficking of ligand-bound integrins through the attenuation of CAV1 activity.

IMPLICATIONS

This study provides valuable new insight into the potential therapeutic benefit of NEDD9 depletion to reduce dissemination of tumor cells and discovers a new regulatory role of NEDD9 in promoting migration through modulation of CAV1-dependent trafficking of integrins.

Bioinformatic approaches to augment study of epithelial-to-mesenchymal transition in lung cancer

Bioinformatic approaches are intended to provide systems level insight into the complex biological processes that underlie serious diseases such as cancer. In this review we describe current bioinformatic resources, and illustrate how they have been used to study a clinically important example: epithelial-to-mesenchymal transition (EMT) in lung cancer. Lung cancer is the leading cause of cancer-related deaths and is often diagnosed at advanced stages, leading to limited therapeutic success. While EMT is essential during development and wound healing, pathological reactivation of this program by cancer cells contributes to metastasis and drug resistance, both major causes of death from lung cancer. Challenges of studying EMT include its transient nature, its molecular and phenotypic heterogeneity, and the complicated networks of rewired signaling cascades. Given the biology of lung cancer and the role of EMT, it is critical to better align the two in order to advance the impact of precision oncology. This task relies heavily on the application of bioinformatic resources. Besides summarizing recent work in this area, we use four EMT-associated genes, TGF-β (TGFB1), NEDD9/HEF1, β-catenin (CTNNB1) and E-cadherin (CDH1), as exemplars to demonstrate the current capacities and limitations of probing bioinformatic resources to inform hypothesis-driven studies with therapeutic goals.

NEDD9/Arf6-dependent endocytic trafficking of matrix metalloproteinase 14: a novel mechanism for blocking mesenchymal cell invasion and metastasis of breast cancer

NEDD9 is an established marker of invasive and metastatic cancers. NEDD9 downregulation has been shown to dramatically reduce cell invasion and metastasis in multiple tumors. The mechanisms by which NEDD9 regulates invasion are largely unknown. In the current study, we have found that NEDD9 is required for MMP14 enzymatic recovery/recycling through the late endosomes to enable disengagement of tissue inhibitor of matrix metalloproteinase 2 (TIMP2) and tumor invasion. Depletion of NEDD9 decreases targeting of the MMP14/TIMP2 complex to late endosomes and increases trafficking of MMP14 from early/sorting endosomes back to the surface in a small GTPase Arf6-dependent manner. NEDD9 directly binds to Arf6-GAP, ARAP3, and Arf6 effector GGA3 thereby facilitating the Arf6 inactivation required for MMP14/TIMP2 targeting to late endosomes. Re-expression of NEDD9 or a decrease in Arf6 activity is sufficient to restore MMP14 activity and the invasive properties of tumor cells. Importantly, NEDD9 inhibition by Vivo-Morpholinos, an antisense therapy, decreases primary tumor growth and metastasis in xenograft models of breast cancer. Collectively, our findings uncover a novel mechanism to control tumor cells dissemination through NEDD9/Arf6-dependent regulation of MMP14/TIMP2 trafficking, and validates NEDD9 as a clinically relevant therapeutic target to treat metastatic cancer.

Genomic microarray analysis on formalin-fixed paraffin-embedded material for uveal melanoma prognostication

Cytogenetic alterations are strong outcome prognosticators in uveal melanoma (UVM). Monosomy 3 (-3) and MYC amplification at 8q24 are commonly tested by fluorescence in situ hybridization (FISH). Alternatively, microarray analysis provides whole genome data, detecting partial chromosome loss, loss of heterozygosity (LOH), or abnormalities unrepresented by FISH probes. Nonfixed frozen tissue is conventionally used for microarray analysis but may not always be available. We assessed the feasibility of genomic microarray analysis for high resolution interrogation of UVM using formalin-fixed paraffin-embedded tissue (FFPET) as an alternative to frozen tissue (FZT). Enucleations from 44 patients (clinical trial NCT00952939) yielded sufficient DNA from FFPET (n = 34) and/or frozen tissue (n = 41) for comparative genomic hybridization and select single nucleotide polymorphism analysis (CGH/SNP) on Roche-NimbleGen OncoChip arrays. CEP3 FISH analysis was performed on matched cytology ThinPrep material. CGH/SNP analysis was successful in 30 of 34 FFPET and 41 of 41 FZT samples. Of 27 paired FFPET/FZT samples, 26 (96.3%) were concordant for at least four of six major recurrent abnormalities (-3, +8q, -1p, +6p, -6q, -8p), and 25 of 27 (92.6%) were concordant for -3. Results of CGH/SNP were concordant with the CEP3 FISH results in 27 of 30 (90%) FFPET and 38 of 41 (92.6%) FZT cases; partial -3q was detected in two CEP3 FISH-negative cases and whole chromosome 3, 4, and 6 SNP-LOH in one case. CGH detection of -3, +8q, -8p on FFPET and FZT showed significant correlation with the clinical outcome measures (metastasis development, time to progression, survival). Results of the UVM genotyping by CGH/SNP on FFPET are highly concordant with those of the FZT analysis and with those of the CEP3 FISH analysis, and therefore CGH/SNP is a practical method for UVM prognostication. Genome-wide coverage provides additional data with potential relevance to UVM biology, diagnosis, and prognosis.

CAS proteins in health and disease: an update

The CAS family of scaffolding proteins has increasingly attracted scrutiny as important for regulation of cancer-associated signaling. BCAR1 (also known as p130Cas), NEDD9 (HEF1, Cas-L), EFS (Sin), and CASS4 (HEPL) are regulated by and mediate cell attachment, growth factor, and chemokine signaling. Altered expression and activity of CAS proteins are now known to promote metastasis and drug resistance in cancer, influence normal development, and contribute to the pathogenesis of heart and pulmonary disease. In this article, we provide an update on recently published studies describing signals regulating and regulated by CAS proteins, and evidence for biological activity of CAS proteins in normal development, cancer, and other pathological conditions.