Decreased expression of updated NESG1 in nasopharyngeal carcinoma: its potential role and preliminarily functional mechanism

CCDC58 is a potential biomarker for diagnosis, prognosis, immunity, and genomic heterogeneity in pan-cancer

Coiled-coil domain-containing 58 (CCDC58) is a member of the CCDC protein family. Similar to other members, CCDC58 exhibits potential tumorigenic roles in a variety of malignancies. However, there is no systematic and comprehensive pan-cancer analysis to investigate the diagnosis, prognosis, immune infiltration, and other related functions of CCDC58. We used several online websites and databases, such as TCGA, GTEx, UALCAN, HPA, CancerSEA, BioGRID, GEPIA 2.0, TIMER 2.0, and TISIDB, to extract CCDC58 expression data and clinical data of patients in pan-cancer. Then, the relationship between CCDC58 expression and diagnosis, prognosis, genetic alterations, DNA methylation, genomic heterogeneity, and immune infiltration level were determined. In addition, the biological function of CCDC58 in liver hepatocellular carcinoma (LIHC) was investigated. Pan-cancer analysis results showed that CCDC58 was differentially expressed in most tumors and showed excellent performance in diagnosis and prediction of prognosis. The expression of CCDC58 was highly correlated with genetic alterations, DNA methylation, and genomic heterogeneity in some tumors. In addition, the correlation analysis of CCDC58 with the level of immune infiltration and immune checkpoint marker genes indicated that CCDC58 might affect the composition of the tumor immune microenvironment. Enrichment analysis showed that CCDC58-related genes were mainly linked to mitosis, chromosome, and cell cycle. Finally, biological function experiments demonstrated that CCDC58 plays an important role in tumor cell proliferation and migration. CCDC58 was first identified as a pan-cancer biomarker. It may be used as a potential therapeutic target to improve the prognosis of patients in the future.

A novel coiled-coil domain containing-related gene signature for predicting prognosis and treatment effect of breast cancer

PURPOSE

Breast cancer (BRCA) is a prevalent tumor worldwide. The association between the coiled-coil domain-containing (CCDC) protein family and different tumors has been established. However, the prognostic significance of this protein family in breast cancer remains uncertain.

METHODS

Gene expression and clinical data were obtained from the TCGA, METABRIC, and GEO databases. Prognosis genes were identified using univariate Cox and LASSO Cox regression, leading to the establishment of a prognostic signature. Subsequently, the risk model was conducted based on survival and clinical feature analyses, and a nomogram for prognosis prediction was developed. Furthermore, analyses of biological function, immune characteristics, and drug sensitivity were performed. Finally, single-cell sequencing data were utilized to uncover the expression patterns of genes in the risk model.

RESULTS

Five genes were identified and utilized for risk modeling. The model demonstrated excellent prognostic value as indicated by ROC and Kaplan-Meier analysis. The high-risk group exhibited shorter survival time and higher likelihood of recurrence. Functional annotation indicated a correlation between the risk score and immune pathways. Conversely, the low-risk group displayed a greater enrichment in immune pathways and exhibited more active immune microenvironment characteristics. Additionally, drug sensitivity analysis using both public and our sequencing data revealed that the risk model possessed a broad range of predictive values.

CONCLUSIONS

We have developed a gene signature and have verified that patients with low-risk are more likely to have better prognosis and respond positively to therapy. This finding offers a valuable point of reference for BRCA individualized treatment.

Regulatory network and targeted interventions for CCDC family in tumor pathogenesis

CCDC (coiled-coil domain-containing) is a coiled helix domain that exists in natural proteins. There are about 180 CCDC family genes, encoding proteins that are involved in intercellular transmembrane signal transduction and genetic signal transcription, among other functions. Alterations in expression, mutation, and DNA promoter methylation of CCDC family genes have been shown to be associated with the pathogenesis of many diseases, including primary ciliary dyskinesia, infertility, and tumors. In recent studies, CCDC family genes have been found to be involved in regulation of growth, invasion, metastasis, chemosensitivity, and other biological behaviors of malignant tumor cells in various cancer types, including nasopharyngeal carcinoma, lung cancer, colorectal cancer, and thyroid cancer. In this review, we summarize the involvement of CCDC family genes in tumor pathogenesis and the relevant upstream and downstream molecular mechanisms. In addition, we summarize the potential of CCDC family genes as tumor therapy targets. The findings discussed here help us to further understand the role and the therapeutic applications of CCDC family genes in tumors.

Immunohistochemical analysis of expression of VEGFR2, KIT, PDGFR-β, and CDK4 in canine urothelial carcinoma

Urothelial carcinomas (UCs), also known as transitional cell carcinomas, are the most common canine urinary tract neoplasms. Tyrosine kinases (TKs) are enzymes that tightly regulate cell growth and differentiation through phosphorylation. Receptor TK (RTK) inhibitors are currently used to treat UCs. Toceranib phosphate (Palladia; Pfizer) is an RTK inhibitor that blocks the activity of vascular endothelial growth factor receptor 2 (VEGFR2), platelet-derived growth factor receptor-alpha and -beta (PDGFR-α, -β), FMS-like tyrosine kinase 3, stem cell factor receptor (KIT, kinase inhibitor targeting), and colony stimulating factor receptor. To better understand UCs and validate treatment targets, we performed immunohistochemical staining for RTKs, as well as a novel target, cyclin-dependent kinase 4 (CDK4, a central regulator of the mammalian cell cycle), on formalin-fixed, paraffin-embedded tissues from bladder biopsies from 17 dogs with UCs, 17 dogs with cystitis (diseased controls), and 8 normal dogs (negative controls). Although immunohistochemical scores could not be extrapolated to prognostic value, response to treatment, and outcome of patients with UC, we demonstrated expression of PDGFR-β and VEGFR2 in UCs; all UC samples staining positively for VEGFR2. Minimal positive staining for KIT was noted in the tumor samples. CDK4 staining intensity was significantly weaker in UCs compared with normal and cystitis bladder samples. The intense staining of VEGFR2 in UC cells suggested that VEGFR2 may be of prognostic and/or therapeutic value in dogs with UC. Overexpression of VEGFR2 in UC cells validates this receptor as a treatment target in UC.

lncRNA-mediated ceRNA network in bladder cancer

Bladder cancer is a common disease associated with high rates of morbidity and mortality. Although immunotherapy approaches such as adoptive T-cell therapy and immune checkpoint blockade have been investigated for the treatment of bladder cancer, their off-target effects and ability to affect only single targets have led to clinical outcomes that are far from satisfactory. Therefore, it is important to identify novel targets that can effectively control tumor growth and metastasis. It is well known that long noncoding RNAs (lncRNAs) are powerful regulators of gene expression. Increasing evidence has shown that dysregulated lncRNAs in bladder cancer are involved in cancer cell proliferation, migration, invasion, apoptosis, and epithelial-mesenchymal transition (EMT). In this review, we focus on the roles and underlying mechanisms of lncRNA-mediated competing endogenous RNA (ceRNA) networks in the regulation of bladder cancer progression. In addition, we discuss the potential of targeting lncRNA-mediated ceRNA networks to overcome cancer treatment resistance and its association with clinicopathological features and outcomes in bladder cancer patients. We hope this review will stimulate research to develop more effective therapeutic approaches for bladder cancer treatment.

Bioactivity of a polyhydroxy gorgostane steroid from Xenia umbellata

A C-30 steroid, 3β-,5α-,6β-,11α-,20β-pentahydroxygorgosterol was isolated from the soft coral Xenia umbellata Lamarck (Xeniidae). The chemical structure was elucidated by examining the NMR spectral data and comparison with the previously published data. Compound 1 inhibited the growth of ovarian cancer (SKOV-3), breast cancers (MCF-7 and MDA-MB-231) and hepatocellular carcinoma (HepG2) using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay. Notably against HepG2, compound 1 showed significant effect with an IC50 value of 19.70 ± 1.98 µg/mL. It significantly increased the population in the SubG1 phase for 2.01- and 2.05-folds, respectively, compared to untreated cells. Additionally, it showed potent inhibitory activities of superoxide dismutase (384.6 vs 8594.2 U/g protein in dimethyl sulfoxide-treated cells), catalase (0.3 vs 0.07 U/g protein), decreased the level of reduced glutathione (1.7 vs 0.6 mg/g protein) and the activity of matrix metalloproteases (MMP-2 and MMP-9 [0.5-fold of change in MMP activity]) in HepG2 cells. The results indicated the potent antiproliferative activity of the gorgostane derivative (1) against HepG2 cells. This study provides a scientific basis of the antiproliferative effects of steroidal compound with gorgostane nucleus against hepatocellular carcinoma cells.

Genomic Assessment of Cancer Susceptibility in the Threatened Catalina Island Fox (Urocyon littoralis catalinae)

Small effective population sizes raise the probability of extinction by increasing the frequency of potentially deleterious alleles and reducing fitness. However, the extent to which cancers play a role in the fitness reduction of genetically depauperate wildlife populations is unknown. Santa Catalina island foxes (Urocyon littoralis catalinae) sampled in 2007-2008 have a high prevalence of ceruminous gland tumors, which was not detected in the population prior to a recent bottleneck caused by a canine distemper epidemic. The disease appears to be associated with inflammation from chronic ear mite (Otodectes) infections and secondary elevated levels of Staphyloccus pseudointermedius bacterial infections. However, no other environmental factors to date have been found to be associated with elevated cancer risk in this population. Here, we used whole genome sequencing of the case and control individuals from two islands to identify candidate loci associated with cancer based on genetic divergence, nucleotide diversity, allele frequency spectrum, and runs of homozygosity. We identified several candidate loci based on genomic signatures and putative gene functions, suggesting that cancer susceptibility in this population may be polygenic. Due to the efforts of a recovery program and weak fitness effects of late-onset disease, the population size has increased, which may allow selection to be more effective in removing these presumably slightly deleterious alleles. Long-term monitoring of the disease alleles, as well as overall genetic diversity, will provide crucial information for the long-term persistence of this threatened population.

Increased PA2G4 Expression Is an Unfavorable Factor in Nasopharyngeal Carcinoma

PA2G4 plays a dual role in tumors. However, the correlation of its expression with clinical feature and prognosis has never been reported in nasopharyngeal carcinoma (NPC). Using immunohistochemical staining, we examined PA2G4 protein level in clinicopathologically characterized 201 NPC cases (138 male and 63 female) with age ranging from 21 to 83 years and 45 nasopharyngeal (NP) tissues. Statistical methods were used to assess the difference in PA2G4 expression and its relationship with clinical parameters and prognosis in NPC. Immunohistochemical analysis showed that the protein expression of PA2G4 examined in NPC tissues was higher than that in the nasopharyngeal tissues (P=0.005). In addition, high levels of PA2G4 protein were positively correlated with tumor size (T classification) (P<0.001), the status of lymph node metastasis (N classification) (P<0.001), distant metastasis (P=0.029), and clinical stage (P<0.001) of NPC patients. Patients with higher PA2G4 expression had a significantly shorter overall survival time than did patients with low PA2G4 expression. Stratified analysis indicated that high expression of PA2G4 showed the inversed survival time in clinical stages III-IV, but not stages I-II. Finally, multivariate analysis suggested that the level of PA2G4 expression was an independent prognostic indicator (P<0.001) for the survival of patients with NPC. Elevated protein expression of PA2G4 was significantly shown, which plays an unfavorable outcome for NPC patient survival.

VPS33B interacts with NESG1 to suppress cell growth and cisplatin chemoresistance in ovarian cancer

The pathogenesis and cisplatin chemoresistance of ovarian cancer (OC) are still unclear. Vacuolar protein sorting‐associated 33B (VPS33B) has not been reported in OC to date. In this study, immunohistochemistry was used to detect VPS33B protein expression between OC and ovarian tissues. MTT, EdU, colony formation, cell cycle, in vivo tumorigenesis, western blot, ChIP, EMSA, co‐immunoprecipitation (CoIP), qRT‐PCR, and microconfocal microscopy were used to explore the function and molecular mechanisms of VPS33B in OC cells. The results of the present study demonstrated that VPS33B protein expression was obviously reduced in OC compared with that in ovarian tissues. Overexpressed VPS33B suppressed cell cycle transition, cell growth, and chemoresistance to cisplatin in vitro and in vivo. Analysis of the mechanism indicated that overexpressed VPS33B regulated the epidermal growth factor receptor (EGFR)/PI3K/AKT/c‐Myc/p53/miR‐133a‐3p feedback loop and reduced the expression of the cell cycle factor CDK4. Nasopharyngeal epithelium‐specific protein 1 (NESG1) as a tumor suppressor not only interacted with VPS33B, but was also induced by VPS33B by the attenuation of PI3K/AKT/c‐Jun‐mediated transcription inhibition. Overexpressed NESG1 further suppressed cell growth by mediating VPS33B‐modulated signals in VPS33B‐overexpressing OC cells. Finally, NESG1 induced VPS33B expression by reducing the inhibition of PI3K/AKT/c‐Jun‐mediated transcription. Our study is the first to demonstrate that VPS33B serves as a tumor suppressor, and VPS33B can interact with NESG1 to suppress cell growth and promote cisplatin sensitivity by regulating the EGFR/PI3K/AKT/c‐Myc/p53/miR‐133a‐3p feedback loop in OC cells.

miR-1254 induced by NESG1 inactivates HDGF/DDX5-stimulated nuclear translocation of β-catenin and suppresses NPC metastasis

Nasopharyngeal carcinoma (NPC) is one of the most common malignant tumors in Chinese and other Southeast Asians. We aimed to explore the precise mechanism for NESG1 in NPC for understanding the pathogenesis of NPC. Transwell, Boyden assays, and wounding healing were respectively performed for cell metastasis. The microRNA (miRNA) microarray and luciferase reporter assays were designed to clarify NESG1-modulated miRNAs and miR-1254-targeted protein. Western blotting assays examined the pathways regulated by miR-1254, the (Hepatoma-Derived Growth Factor) HDGF/DDX5 complex, and NESG1. The chromatin immunoprecipitation (ChIP), electrophoretic mobility shift assay (EMSA), and co-immunoprecipitation (coIP) assays were used to explore the DNA-protein complex and protein-protein complex. NESG1 suppressed NPC migration and invasion via Wnt/β-catenin signaling. Further, miR-1254 was confirmed as a positive downstream modulator of NESG1 reducing metastatic abilities of NPC cells in vivo and in vitro. Transduction of HDGF significantly restored cell migration and invasion ability in miR-1254-overexpressing NPC cells. In clinical samples, miR-1254 expression was negatively correlated with HDGF and positively correlated with NESG1 expression. miR-1254 acts as an independent prognostic factor for NPC, which was induced by NESG1 to suppress NPC metastasis via inactivating Wnt/β-catenin pathway and its downstream EMT signals.

Coiled-coil domain-containing 68 promotes non-small cell lung cancer cell proliferation in vitro

Coiled-coil domain-containing 68 (CCDC68) is a novel secretory protein that acts as a tumor suppressor gene in several types of malignant tumors. However, the role of CCDC68 in the development of lung cancer has not been extensively studied. In the present study, to explore the biological functions of CCDC68 in NSCLC, we performed cell proliferation, viability and apoptosis assays on human lung cancer cell lines upon CCDC68 gene silencing with short hairpin RNA. The results demonstrated that following knockdown of CCDC68 expression, cell proliferation was decreased and the apoptotic rates were increased in A549 and H1299 cells. The role and mechanism of CCDC68 in malignant tumors, particularly in lung cancer, should be further explored, and CCDC68 may serve as a novel target for treatment of lung cancer.

VPS33B suppresses lung adenocarcinoma metastasis and chemoresistance to cisplatin

The presence of VPS33B in tumors has rarely been reported. Downregulated VPS33B protein expression is an unfavorable factor that promotes the pathogenesis of lung adenocarcinoma (LUAD). Overexpressed VPS33B was shown to reduce the migration, invasion, metastasis, and chemoresistance of LUAD cells to cisplatin (DDP) in vivo and in vitro. Mechanistic analyses have indicated that VPS33B first suppresses epidermal growth factor receptor (EGFR) Ras/ERK signaling, which further reduces the expression of the oncogenic factor c-Myc. Downregulated c-Myc expression reduces the rate at which it binds the p53 promoter and weakens its transcription inhibition; therefore, decreased c-Myc stimulates p53 expression, leading to decreased epithelial-to-mesenchymal transition (EMT) signal. NESG1 has been shown to be an unfavorable indicator of non-small-cell lung cancer (NSCLC). Here, NESG1 was identified as an interactive protein of VPS33B. In addition, NESG1 was found to exhibit mutual stimulation with VPS33B via reduced RAS/ERK/c-Jun-mediated transcription repression. Knockdown of NESG1 activated EGFR/Ras/ERK/c-Myc signaling and further downregulated p53 expression, which thus activated EMT signaling and promoted LUAD migration and invasion. Finally, we observed that nicotine suppressed VPS33B expression by inducing PI3K/AKT/c-Jun-mediated transcription suppression. Our study demonstrates that VPS33B as a tumor suppressor is significantly involved in the pathogenesis of LUAD.

Positive feedback loop of FAM83A/PI3K/AKT/c-Jun induces migration, invasion and metastasis in hepatocellular carcinoma

FAM83A is part of an 8-member protein family of unknown function and is reported to be a cancer-promoting and treatment-resistance factor in several cancers. However, its role in hepatocellular carcinoma (HCC) remains unclear. Analysis of the Cancer Genome Atlas (TCGA) showed that FAM83A mRNA expression is upregulated in HCC, as are the protein expression levels in both HCC cell lines and tissues. Clinical data have demonstrated that high FAM83A expression is positively correlated with poor progression-free survival time, thus suggesting its cancer-promoting potential. Functional analyses showed that FAM83A overexpression promoted HCC cell migration and invasion in vitro and suppressed sorafenib sensitivity. Inhibiting FAM83A reversed these results. A pulmonary metastasis model further confirmed that FAM83A promoted HCC cell metastasis in vivo. Mechanistic analyses indicated that FAM83A activated the PI3K/AKT signaling pathway, its downstream c-JUN protein, and epithelial-to-mesenchymal transition (EMT)-related protein levels, including downregulation of E-cadherin and upregulation of Vimentin and N-cadherin. Interestingly, c-JUN induced FAM83A expression by directly binding to its promoter region and thus forming a positive-feedback loop for FAM83A/PI3K/AKT/c-JUN. In conclusion, we demonstrated that FAM83A, as a cancer-metastasis promoter, accelerates migration, invasion and metastasis by activating the PI3K/AKT/c-JUN pathway and inducing its self-expression via feedback, thus forming a FAM83A/PI3K/AKT/c-JUN positive-feedback loop to activate EMT signaling and finally promote HCC migration, invasion and metastasis.

VPS33B negatively modulated by nicotine functions as a tumor suppressor in colorectal cancer

The biological role of vacuolar protein sorting 33B (VPS33B) has not been examined in colorectal cancer (CRC). We report that VPS33B was downregulated in dextran sulfate sodium/azoxymethane (DSS/AOM) -induced CRC mice models and nicotine-treated CRC cells via the PI3K/AKT/c-Jun pathway. Reduced VPS33B is an unfavorable factor promoting poor prognosis in human CRC patients. VPS33B overexpression suppressed CRC proliferation, intrahepatic metastasis and chemoresistance of cisplatin (DDP) in vivo and in vitro through modulating the epidermal growth factor receptor (EGFR)/RAS/ERK/c-Myc/p53/miR-133a-3p feedback loop and the downstream cell cycle or EMT-related factors. Furthermore, NESG1 as a newly identified tumor suppressor interacted with VPS33B via colocalization in the cytoplasm, and it was stimulated by VPS33B through the downregulation of RAS/ERK/c-Jun-mediated transcription. NESG1 also activated VPS33B expression via the RAS/ERK/c-Jun pathway. Suppression of NESG1 increased cell growth, migration and invasion via the reversion of the VPS33B-modulating signal in VPS33B-overexpressed cells. Taken together, VPS33B as a tumor suppressor is easily dysregulated by chemical carcinogens and it interacts with NESG1 to modulate the EGFR/RAS/ERK/c-Myc/p53/miR-133a-3p feedback loop and thus suppress the malignant phenotype of CRC.

VPS33B interacts with NESG1 to modulate EGFR/PI3K/AKT/c-Myc/P53/miR-133a-3p signaling and induce 5-fluorouracil sensitivity in nasopharyngeal carcinoma

The vacuolar protein sorting 33B (VPS33B) was rarely reported in malignant tumors. In this research, we demonstrated that overexpression of VPS33B inhibited proliferation and chemoresistance to fluorouracil (5-FU) in nasopharyngeal carcinoma (NPC) in vivo and in vitro. Mechanistic analysis confirmed that overexpression of VPS33B modulated EGFR/PI3K/AKT/c-Myc/P53 signaling to arrest the cell cycle at G1/S phase. In addition, miR-133a-3p, a tumor-suppressive miRNA, was induced by P53 and directly targeted the EGFR/PI3K/AKT/c-Myc/P53 signaling and thus formed a negative feedback loop. Furthermore, another tumor suppressor, NESG1, interacted with VPS33B by colocalizing in the cytoplasm. The knockdown of NESG1 reversed the inhibitory effects of the overexpression of VPS33B in NPC cells by downregulating the PI3K/AKT/c-Jun-mediated transcription repression. Surprisingly, VPS33B was downregulated in the nicotine-treated and LMP-1-overexpressing NPC cells by targeting PI3K/AKT/c-Jun-mediated signaling. In addition, patients with higher VPS33B expression had a longer overall survival. Our study is the first to demonstrate that VPS33B is negatively regulated by LMP-1 and nicotine and thus suppresses the proliferation of NPC cells by interacting with NESG1 to regulate EGFR/PI3K/AKT/c-Myc/P53/miR-133a-3p signaling in NPC cells.

VPS33B interacts with NESG1 to modulate EGFR/PI3K/AKT/c-Myc/P53/miR-133a-3p signaling and induce 5-Fluorouracil sensitivity in nasopharyngeal carcinoma, and VPS33B was inhibited by LMP-1 and nicotine.

Long noncoding RNA MAGI2-AS3 regulates CCDC19 expression by sponging miR-15b-5p and suppresses bladder cancer progression

Bladder cancer (BCa) belongs to a popular urological malignancy and leads to large numbers of deaths worldwide. Recently, emerging evidences indicate that long noncoding RNAs (lncRNAs) are closely related with BC occurrence and progression. However, the function of lncRNA MAGI2-AS3 remains poorly understood in BC. In this present study, we screened out a novel lncRNA MAGI2-AS3 whose expression was downregulated in BCa tissues. We showed that MAGI2-AS3 downregulation in BCa patients indicated a poor prognosis. Functionally, we showed that MAGI2-AS3 overexpression inhibits proliferation, migration and invasion of BCa cells. Moreover, ectopic expression of MAGI2-AS3 suppresses BCa growth in vivo. Bioinformatics analysis revealed that MAGI2-AS3 could serve as a competing endogenous RNA (ceRNA) for miR-15b-5p. In the meantime, miR-15b-5p directly targeted CCDC19, a tumor suppressor in BCa. Rescue assays demonstrated that knockdown of CCDC19 restored the proliferation, migration and invasion of BCa cells suppressed by MAGI2-AS3 overexpression. In conclusion, this study identified a novel mechanism that MAGI2-AS3/miR-15b-5p/CCDC19 signaling pathway regulates BCa progression.

Overexpression of Coiled-Coil Domain-Containing Protein 34 (CCDC34) and its Correlation with Angiogenesis in Esophageal Squamous Cell Carcinoma

Background

The coiled-coil domain-containing proteins have been shown to have a series of functions in biological synthesis. Recent studies have found that CCDC34 is highly expressed in bladder cancer, but the underlying molecular mechanisms still remain unclear. Therefore, we performed the present study to assess the expression of the coiled-coil domain-containing protein 34 (CCDC34) in esophageal squamous cell carcinoma (ESCC) patients. We also explored the relationships between CCDC34 expression and clinicopathologic characteristics, tumor angiogenesis, and prognosis.

Material/Methods

We detected the expressions of CCDC34, VEGF, and MVD by immunohistochemical technique in 100 cases of ESCC and 80 cases of corresponding paracarcinomatous normal tissues. The relationship between CCDC34 expression and clinicopathologic characteristics, tumor angiogenesis, and prognosis were also explored.

Results

The expression of CCDC34 protein was obviously increased in ESCC tissues, which was significantly correlated with sex (p=0.038), TNM stage (p=0.003), and lymphatic metastasis (p=0.024). In addition, we found that the expression of CCDC34 was an independent prognostic factor for ESCC patients. The overexpression of CCDC34 protein in ESCC was associated with tumor progression, angiogenesis, and poor survival.

Conclusions

Our results demonstrate that CCDC34 is overexpressed in ESCC and can be used as an independent parameter for indicating the poor prognosis of ESCC patients, suggesting that CCDC34 might be a new potential therapeutic target for ESCC patients in the future.

Silencing of lncRNA CCDC26 Restrains the Growth and Migration of Glioma Cells In Vitro and In Vivo via Targeting miR-203

Gliomas are the most common primary brain tumors with high mortality. The treatment for gliomas is largely limited due to its uncomprehending pathological mechanism. Here we aimed to investigate the effect of long noncoding RNA (lncRNA) coiled-coil domain-containing 26 (CCDC26) in glioma progression. In our study, the expression of CCDC26 was found upregulated in glioma tissues and cell lines compared with normal tissues and cell lines. Further exploration detected decreased cell proliferation and increased cell apoptosis in U-251 and M059J cells transfected with CCDC26-siRNA. In addition, the silencing of CCDC26 strongly reduced the wound closing rate and the number of invasive cells compared with the scramble group. Simultaneously, the expression of miR-203 was found suppressed in glioma tissues and cells lines. Suppressed level of miR-203 was then elevated in U-251 and M059J cells transfected with CCDC26-siRNA. The result of the luciferase activity assay also showed that the luciferase activity was strongly strengthened by adding the miR-203 inhibitor into the CCDC26 WT group. Moreover, CDCC26-siRNA counteracted the effect of the miR-203 inhibitor in facilitating cell viability and mobility in U-251 cells. The in vivo experiment also revealed that CCDC26-siRNA inhibited glioma growth and metastasis. Taken together, our research indicated a CCDC26/miR-203 pathway in regulating the growth and metastasis of gliomas, providing new viewpoints and promising targets for glioma therapy.

Direct interaction between miR-203 and ZEB2 suppresses epithelial-mesenchymal transition signaling and reduces lung adenocarcinoma chemoresistance

miR-203 is a tumor suppressor which participates in the pathogenesis of many tumors including lung adenocarcinoma. However, the role of miR-203 in suppressing chemotherapy resistance to cisplatin (cis-diamminedichloroplatinum; DDP) as well as its molecular mechanism is still to be determined in lung adenocarcinoma. In this study, we found that miR-203 decreased lung cancer cell migration and invasion, and that increased miR-203 expression sensitized lung adenocarcinoma cells to DDP in vitro Furthermore, ZEB2 was found to be a direct target of miR-203, which induces epithelial-mesenchymal transition (EMT) signal. Knock-down of ZEB2 significantly increased DDP chemosensitivity in lung adenocarcinoma. More interestingly, we also demonstrated that ZEB2 could directly bind to E-box of the miR-203 promoter and suppress its expression in lung adenocarcinoma. Our data reveal that miR-203 serves as a negative feedback by directly suppressing the upstream ZEB2 gene, which inhibits EMT signaling and reduces chemoresistance of DDP. Together, these results highlight a feedback loop between miR-203 and ZEB2, which participates in the pathogenesis of lung adenocarcinoma.

MiR-25 promotes hepatocellular carcinoma cell growth, migration and invasion by inhibiting RhoGDI1

MicroRNA (miRNA)-25 is a small non-coding RNA that has been implicated in the tumorigenesis of many cancers, but little is known on the role of miR-25 in HCC metastasis. We hereby found that miR-25 was significantly upregulated in clinical HCC tissues compared with normal liver tissues. We also revealed that miR-25 dramatically stimulates HCC cell growth and activates the epithelial-mesenchymal transition (EMT). MiR-25 is activated by the WNT/β-catenin signaling pathway, and exerts its pro-metastatic function by directly inhibiting the Rho GDP dissociation inhibitor alpha (RhoGDI1). Downregulation of RhoGDI1 enhances expression of Snail, thereby promoting EMT. MiR-25 levels are positively correlated with β-catenin expression, whereas negatively correlated with the level of RhoGDI1 in HCC. Our findings provide new insights into the role of miR-25 in HCC metastasis, and implicate the potential application of miR-25 in HCC therapy.

CCDC34 is up-regulated in bladder cancer and regulates bladder cancer cell proliferation, apoptosis and migration

The coiled coil is a superhelical structural protein motif involved in a diverse array of biological functions, and the abnormal expression of the coiled-coil domain containing proteins has a direct link with the phenotype of tumor cell migration, invasion and metastasis. The aim of this study was to investigate the critical role of Coiled-coil domain-containing protein 34 (CCDC34) in bladder carcinogenesis, which has never been reported to date. Here, we found CCDC34 expression was elevated in bladder cancer tissues and cell lines. The knockdown of CCDC34 via lentivirus-mediated siRNA significantly suppressed bladder cancer cells proliferation and migration, and induced cell cycle arrest at G2/M phase and increased apoptosis in vitro. In addition, CCDC34 knockdown suppressed bladder tumor growth in nude mice. Moreover, CCDC34 silencing decreased the phosphorylation of MEK, ERK1/2, JNK, p38 and Akt, and the expressions of c-Raf and c-Jun, indicating MAPK and AKT pathways (ERK/MAPK, p38/MAPK, JNK/MAPK and PI3K/Akt) might be involved in CCDC34 regulation of bladder cancer cell proliferation and migration. Our findings revealed for the first time a potential oncogenic role for CCDC34 in bladder carcinoma pathogenesis and it may serve as a biomarker or even a therapeutic target for bladder cancer.

LATS2 as a poor prognostic marker regulates non-small cell lung cancer invasion by modulating MMPs expression

Large tumor suppressor 2 (LATS2) plays significant roles in tumorigenesis and cancer progression. This study was aimed to analyze the correlation between LATS2 expression and clinicopathologic features and its prognostic significance in non-small cell lung cancer (NSCLC). LATS2 expression was examined in 73 NSCLC clinical specimens and 22 normal lung tissues using immunohistochemistry. Low levels of LATS2 protein were inversely associated with the T classification (P=0.001), N classification (P=0.005) and clinical stage (P=0.001) in NSCLC patients. Patients with lower LATS2 expression had a significantly shorter overall survival than patients with high LATS2 expression. Multivariate analysis suggested that low expression of LATS2 was an independent prognostic indicator (P=0.002) for the survival of patients with NSCLC. Furthermore, overexpression of LATS2 resulted in mobility inhibition in NSCLC cell lines A549 and H1299, and reduced protein level of matrix metalloproteinase-2 (MMP-2) and MMP-9. On the contrary, LATS2 siRNA treatment enhanced cell mobility and increased MMP-2 and MMP-9 protein expression level. In conclusion, low expression of LATS2 is a potential unfavorable prognostic factor and promoted cell invasion and migration in NSCLC.

Upregulated Expression of SOX4 Is Associated with Tumor Growth and Metastasis in Nasopharyngeal Carcinoma

SOX4, which belongs to the sex-determining region Y-related high-mobility group (SRY) box family, plays a critical role in embryonic development, cell fate decision, differentiation, and tumor development. Nasopharyngeal carcinoma (NPC) is one of the most common cancers in China and Southeast Asia. However, the molecular mechanisms of this disease remain unknown. In the present study, we used immunohistochemistry to investigate the correlation between the expression of SOX4 with clinicopathologic variables as well as patients prognosis of NPC. We found overexpression of SOX4 was correlated with clinical stages, lymph node metastasis, and Ki-67 expression in NPC (P < 0.05). Besides, patients who expressed higher levels of SOX4 had poorer survival rate (P < 0.05). Then, in vitro studies, we took serum starvation-refeeding experiment and knocked down the expression of SOX4 with siRNA to demonstrate that SOX4 could promote proliferation of NPC nonkeratinizing cell line CNE2. The regulation of SOX4 on cell migration was determined by the transwell migration assay and wounding healing assay. Besides, we also found SOX4 could promote epithelial-mesenchymal transition (EMT) of CNE2 cells and decrease their cisplatin sensitivity. Our data suggested that SOX4 might play an important role in regulating NPC progression and would provide a potential therapeutic strategy for NPC.

A Review: Proteomics in Nasopharyngeal Carcinoma

Although radiotherapy is generally effective in the treatment of major nasopharyngeal carcinoma (NPC), this treatment still makes approximately 20% of patients radioresistant. Therefore, the identification of blood or biopsy biomarkers that can predict the treatment response to radioresistance and that can diagnosis early stages of NPC would be highly useful to improve this situation. Proteomics is widely used in NPC for searching biomarkers and comparing differentially expressed proteins. In this review, an overview of proteomics with different samples related to NPC and common proteomics methods was made. In conclusion, identical proteins are sorted as follows: Keratin is ranked the highest followed by such proteins as annexin, heat shock protein, 14-3-3σ, nm-23 protein, cathepsin, heterogeneous nuclear ribonucleoproteins, enolase, triosephosphate isomerase, stathmin, prohibitin, and vimentin. This ranking indicates that these proteins may be NPC-related proteins and have potential value for further studies.

Overexpression of HMGA1 correlates with the malignant status and prognosis of breast cancer

High mobility group A1 (HMGA1), as a major member of HMGA family, plays an important part in promotion of cell proliferation and motility, induction of epithelial-mesenchymal transition, and maintenance of stemness, but little is known about the pathological role of HMGA1 in breast cancer patients. The aim of this study was to identify the pathological roles of HMGA1 in breast cancer. In our results, we found that mRNA and protein expression levels of HMGA1 were markedly higher in breast cancer tissues than in normal breast tissues. Using immunohistochemistry, high levels of HMGA1 protein were positively correlated with the status of histological grade (I-II vs. III-IV; P = 0.023), clinical stage (I-II vs. III-IV; P = 0.008), tumor size (T1-T2 vs. T3-T4; P = 0.015), lymph node metastasis (N0-N1 vs. N2-N3; P = 0.002), distant metastasis (M0 vs. M1; P < 0.001), and triple-negative breast cancer (No vs. Yes; P = 0.014) of breast cancer patients. Patients with higher HMGA1 expression had a significantly shorter overall survival time than did patients with low HMGA1 expression. Multivariate analysis indicated that the level of HMGA1 expression was an independent prognostic indicator (P < 0.001) for the survival of patients with breast cancer. In conclusion, HMGA1 plays an important role on breast cancer aggressiveness and prognosis and may act as a promising target for prognostic prediction.

Decreased miRNA-637 is an unfavorable prognosis marker and promotes glioma cell growth, migration and invasion via direct targeting Akt1

Although increasing evidence indicated that the deregulation of microRNAs (miRNAs) contributes to tumorigenesis and invasion, little is known about the role of miR-637 in human gliomas. In the present study, we found that the expression level of miR-637 was significantly reduced in clinical glioma tissues compared with normal brain tissues. Moreover, we revealed that the introduction of miR-637 dramatically suppressed glioma cell growth, migration and invasion in vitro and in vivo. Further studies revealed that Akt1 is a direct target gene of miR-637. Silencing of Akt1 inhibited the growth and invasion of glioma cells by decreasing phosphorylated Akt, β-catenin, phosphorylated Foxo1 and Cyclin D1 and inducing the expression of Foxo1, which was consistent with the effect of miR-637 overexpression. Suppressed expression of miR-637 and increased Akt1 protein levels were correlated with unfavorable progression and poor prognosis, respectively, and a negative relationship between the miR-637 expression and Akt1 protein levels was observed in gliomas. Our findings provide new insights into the role of miR-637 in the development of gliomas, and implicate the potential application of miR-637 in cancer therapy.

Candidate tumour suppressor CCDC19 regulates miR-184 direct targeting of C-Myc thereby suppressing cell growth in non-small cell lung cancers

We previously reported and revised the nasopharyngeal epithelium specific protein CCDC19 and identified it as a potential tumour suppressor in nasopharyngeal carcinoma. The purpose of this study was to investigate the involvement of CCDC19 in the pathogenesis of human non-small cell lung cancers (NSCLC). Down-regulated CCDC19 expression was observed in NSCLC tissues and cells compared to normal tissues. However, reduced protein expression did not correlate with the status of NSCLC progression. Instead, we observed that patients with lower CCDC19 expression had a shorter overall survival than did patients with higher CCDC19 expression. Lentiviral-mediated CCDC19 overexpression significantly suppressed cell proliferation and cell cycle transition from G1 to S and G2 phases in NSCLC cells. Knocking down CCDC19 expression significantly restored the ability of cell growth in CCDC19 overexpressing NSCLC cells. Mechanistically CCDC19 functions as a potential tumour suppressor by stimulating miR-184 suppression of C-Myc thus blocking cell growth mediated by the PI3K/AKT/C-Jun pathway. Our studies are the first to demonstrate that reduced expression of CCDC19 is an unfavourable factor in NSCLC.

Alpha-enolase as a potential cancer prognostic marker promotes cell growth, migration, and invasion in glioma

BACKGROUND

The success of using glycolytic inhibitors for cancer treatment relies on better understanding the roles of each frequently deregulated glycolytic genes in cancer. This report analyzed the involvement of a key glycolytic enzyme, alpha-enolase (ENO1), in tumor progression and prognosis of human glioma.

METHODS

ENO1 expression levels were examined in glioma tissues and normal brain (NB) tissues. The molecular mechanisms of ENO1 expression and its effects on cell growth, migration and invasion were also explored by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, Transwell chamber assay, Boyden chamber assay, Western blot and in vivo tumorigenesis in nude mice.

RESULTS

ENO1 mRNA and protein levels were upregulated in glioma tissues compared to NB. In addition, increased ENO1 was associated disease progression in glioma samples. Knocking down ENO1 expression not only significantly decreased cell proliferation, but also markedly inhibited cell migration and invasion as well as in vivo tumorigenesis. Mechanistic analyses revealed that Cyclin D1, Cyclin E1, pRb, and NF-κB were downregulated after stable ENO1 knockdown in glioma U251 and U87 cells. Conversely, knockdown of ENO1 resulted in restoration of E-cadherin expression and suppression of mesenchymal cell markers, such as Vimentin, Snail, N-Cadherin, β-Catenin and Slug. Furthermore, ENO1 suppression inactivated PI3K/Akt pathway regulating the cell growth and epithelial-mesenchymal transition (EMT) progression.

CONCLUSION

Overexpression of ENO1 is associated with glioma progression. Knockdown of ENO1 expression led to suppressed cell growth, migration and invasion progression by inactivating the PI3K/Akt pathway in glioma cells.

TGFβR2 is a major target of miR-93 in nasopharyngeal carcinoma aggressiveness

Background

MiR-17-92 cluster and its paralogues have emerged as crucial regulators of many oncogenes and tumor suppressors. Transforming growth factor-β receptor II (TGFβR2), as an important tumor suppressor, is involved in various cancer types. However, it is in cancer that only two miRNAs of this cluster and its paralogues have been reported so far to regulate TGFβR2. MiR-93 is oncogenic, but its targetome in cancer has not been fully defined. The role of miR-93 in nasopharyngeal carcinoma (NPC) still remains largely unknown.

Methods

We firstly evaluated the clinical signature of TGFβR2 down-regulation in clinical samples, and next used a miRNA expression profiling analysis followed by multi-validations, including Luciferase reporter assay, to identify miRNAs targeting TGFβR2 in NPC. In vitro and in vivo studies were performed to further investigate the effects of miRNA-mediated TGFβR2 down-regulation on NPC aggressiveness. Finally, mechanism studies were conducted to explore the associated pathway and genes influenced by this miRNA-mediated TGFβR2 down-regulation.

Results

TGFβR2 was down-regulated in more than 50% of NPC patients. It is an unfavorable prognosis factor contributing to clinical NPC aggressiveness. A cluster set of 4 TGFβR2-associated miRNAs was identified; they are all from miR-17-92 cluster and its paralogues, of which miR-93 was one of the most significant miRNAs, directly targeting TGFβR2, promoting cell proliferation, invasion and metastasis in vitro and in vivo. Moreover, miR-93 resulted in the attenuation of Smad-dependent TGF-β signaling and the activation of PI3K/Akt pathway by suppressing TGFβR2, further promoting NPC cell uncontrolled growth, invasion, metastasis and EMT-like process. Impressively, the knockdown of TGFβR2 by siRNA displayed a consentaneous phenocopy with the effect of miR-93 in NPC cells, supporting TGFβR2 is a major target of miR-93. Our findings were also substantiated by investigation of the clinical signatures of miR-93 and TGFβR2 in NPC.

Conclusion

The present study reports an involvement of miR-93-mediated TGFβR2 down-regulation in NPC aggressiveness, thus giving extended insights into molecular mechanisms underlying cancer aggressiveness. Approaches aimed at blocking miR-93 may serve as a promising therapeutic strategy for treating NPC patients.

Downregulation of miR-106b induced breast cancer cell invasion and motility in association with overexpression of matrix metalloproteinase 2

Breast cancer (BC) is one of the most common cancers in women, and it can often metastasize to the bone. The mechanism of BC bone metastasis remains unclear and requires in-depth investigation. In a previous study, we found the expression of matrix metalloproteinase 2 (MMP2) to be significantly more pronounced at metastatic bone sites than at orthotopic sites. MicroRNA expression profiling showed miR-106b to be markedly downregulated during BC bone metastasis. However, the specific manner in which MMP2 and miR-106b are involved in the BC bone metastasis is still unclear. In the present study, we found MMP2 expression in orthotopic tumor tissue to be related to the risk of bone metastasis in BC patients. MiR-106b levels in orthotopic tumor tissue showed a negative correlation with MMP2 expression and breast cancer bone metastasis. MMP2 was shown to be a direct target of miR-106b. Both gain- and loss-of-function studies showed that MMP2 could promote the migration and invasion of BC cells and that miR-106b could suppress both. The blockage of MMP2 by RNA interference mimicked the anti-migration and anti-invasion effects of miR-106b, and introduction of MMP2 antagonized the function of miR-106b. MMP2 was also found to regulate the ERK signaling cascade and so adjust the bone microenvironment to favor osteoclastogenesis and bone metastasis. These results suggest that MMP2 upregulation plays an important role in BC bone metastasis through ERK pathways, and miR-106b directly regulates MMP2 expression. The miR-106b/MMP2/ERK pathway may be a promising therapeutic target for inhibiting BC bone metastasis.

Tumor suppressor PDCD4 modulates miR-184-mediated direct suppression of C-MYC and BCL2 blocking cell growth and survival in nasopharyngeal carcinoma

Programmed cell death 4 (PDCD4), a novel tumor suppressor, inhibits cell proliferation, migration and invasion as well as promotes cell apoptosis in tumors. However, the molecular mechanism of its tumor-suppressive function remains largely unknown in tumors including nasopharyngeal carcinoma (NPC). In this study, downregulated PDCD4 expression was significantly associated with the status of NPC progression and poor prognosis. PDCD4 markedly suppressed the ability of cell proliferation and cell survival by modulating C-MYC-controlled cell cycle and BCL-2-mediated mitochondrion apoptosis resistance signals, and oncogenic transcription factor C-JUN in NPC. Furthermore, miR-184, a tumor-suppressive miRNA modulated by PDCD4 directly targeting BCL2 and C-MYC, participated in PDCD4-mediated suppression of cell proliferation and survival in NPC. Further, we found that PDCD4 decreased the binding of C-Jun to the AP-1 element on the miR-184 promoter regions by PI3K/AKT/JNK/C-Jun pathway and stimulated miR-184 expression. In clinical fresh specimens, reduced PDCD4 mRNA level was positively correlated with miR-184 expression in NPC. Our studies are the first to demonstrate that PDCD4 as tumor suppressor regulated miR-184-mediated direct targeting of BCL2 and C-MYC via PI3K/AKT and JNK/C-Jun pathway attenuating cell proliferation and survival in NPC.

Loss of cytoplasmic KLF4 expression is correlated with the progression and poor prognosis of nasopharyngeal carcinoma

AIMS

To examine, in nasopharyngeal carcinoma (NPC), the correlation of Krüppel-like factor 4 (KLF4) expression with clinicopathological features including patient prognosis.

METHODS AND RESULTS

Using real-time PCR and immunohistochemistry, expression of KLF4 mRNA and protein was examined in NPC and nasopharyngeal tissues. The relationship of KLF4 expression levels with clinical features and prognosis of NPC patients was analysed. mRNA expression was markedly lower in NPC than in the nasopharyngeal tissues. Using immunohistochemistry, staining for KLF4 protein was found in the nuclei and cytoplasm of nasopharyngeal and malignant epithelial cells, but decreased cytoplasmic expression was observed in atypical hyperplasia and NPC samples compared to normal and squamous epithelium samples (P < 0.001). In addition, levels of cytoplasmic KLF4 protein were correlated inversely with the nodal (N) status (TNM classification; P = 0.002) and overall clinical stage (P < 0.001) of NPC patients. Patients with NPC showing lower cytoplasmic KLF4 expression had a significantly shorter overall survival time than those with high NPC KLF4 expression. Multivariate analysis suggested that the level of KLF4 expression was an independent prognostic indicator (P = 0.008) for NPC survival.

CONCLUSION

Low levels of cytoplasmic KLF4 expression are a potentially unfavourable prognostic factor for patients with NPC.

Proteomic features of potential tumor suppressor NESG1 in nasopharyngeal carcinoma

We previously defined the recently revised NESG1 gene as a potential tumor suppressor in nasopharyngeal carcinoma (NPC). Here, we further used proteomics technology to globally examine NESG1-controlled proteins in NPC cells. Twenty-six proteins were found to be deregulated by NESG1 using proteomics analysis while enolase 1 (alpha) (ENO1), heat shock protein 90 kDa beta (Grp94), member 1 (HSP90B1), and cathepsin D (CTSD) proteins were differentially expressed by Western blot. Interestingly, a-enolase (ENO1), an overexpressed gene in NPC, was confirmed as a NESG1-regulated protein in NPC cells. Overexpressed ENO1 not only restored cell proliferation and cell-cycle progression, but also antagonized the regulation of NESG1 to cell-cycle regulators p21 and CCNA1 expression as well as induced the expression of C-Myc, pRB, and E2F1 in NESG1-ovexpressed NPC cells. Real-time PCR and immunohistochemistry analysis showed that NESG1 expression is negatively correlated with ENO1 expression in NPC tissues. Our observations suggest that ENO1 downregulation plays an important role in NESG1-induced growth inhibition of NPC cancer cells.

Decreased expression of LATS1 is correlated with the progression and prognosis of glioma

Background

LATS1 is a tumor suppressor genes implicated in the pathogenesis of certain types of tumors, but its role is not known in human glioma.

Methods

Using real-time PCR and immunohistochemistry, we detected the mRNA and protein expression of LATS1 in glioma. The effect of LATS1 on cell growth and invasion were investigated.

Results

We found that mRNA and protein of LATS1 expression is significantly downregulated in glioma compared with normal control brain tissues. Furthermore, reduced LATS1 expression was markedly negatively correlated with WHO grade and KPS (p<0.001 and p<0.001) in glioma patients. Patients with lower LATS1 expression had a significantly shorter overall survival time than did patients with higher LATS1 expression. Multivariate analysis suggested that the level of LATS1 expression was an independent prognostic indicator (p<0.001) for the survival of patients with glioma. Forced expression of LATS1 in glioma U251 cells not only significantly suppressed cell growth, migration and invasion, but retarded cell cycle progression from G2/M to G1 in vitro. Finally, we found that overexpressed LATS1 markedly inhibited the expression level of cell cycle factor CCNA1.

Conclusion

These results indicate that LATS1 is an important candidate tumor suppressor and its downregulated expression may contribute to glioma progression.

Overexpressed DNA-binding protein inhibitor 2 as an unfavorable prognosis factor promotes cell proliferation in nasopharyngeal carcinoma

The aim of the present study was to analyze the expression of DNA-binding protein inhibitor 2 (ID2) in nasopharyngeal carcinoma (NPC) and its correlation with clinicopathological features. It was found that the expression of ID2 was significantly increased in NPC cells when compared with that in NP69 cell line. Similar level of ID2 cytoplasmic expression was observed in NPC when compared with that in non-cancerous nasopharynx tissues. However, the level of ID2 in nucleus was increased in NPC when compared with that in normal nasopharynx tissues. Furthermore, the higher expression level of nuclear ID2 was significantly associated with tumor size (T classification), lymph node metastasis (N classification), and clinical stage. Patients with increased ID2 expression level had poorer overall survival rates than those with low ID2 levels. The inhibition of ID2 expression in NPC cell line SUNE1 by lentiviral-mediated short hairpin RNA could suppress cell proliferation and colony formation, but did not disrupt cell migration. Knocking down the expression of ID2 by RNA interference could down-regulate the expression of Snail, suggesting that ID2-promoted cell growth, partially attributing to the regulation of Snail activity in NPC. Our study demonstrated that over-expression of ID2 protein is an unfavorable prognostic factor which promotes cell proliferation in NPC.

Epigenetic alteration of CCDC67 and its tumor suppressor function in gastric cancer

In this study, the promoter of the gene coiled-coil domain-containing 67 (CCDC67) was found to be frequently methylated in gastric cancer cell lines and in primary gastric tumors, as examined by restriction landmark genomic scanning. In addition, CCDC67 expression was down-regulated in 72.7% of gastric cancer cell lines tested. In most cases, gene down-regulation was associated with CpG hypermethylation in the CCDC67 promoter. Treatment with 5-aza-2'-deoxycytidine and/or trichostatin A restored CCDC67 expression in down-regulated cell lines. Pyrosequencing analysis of 150 paired primary gastric cancer samples revealed that promoter CpG methylation was increased in 74% of tested tumors compared with paired adjacent normal tissues, and this hypermethylation correlated significantly with down-regulation of CCDC67. CCDC67 protein was localized to the cell membrane by immunocytochemistry. Stable transfection of a CCDC67 gene in one gastric cancer cell line inhibited adhesion-dependent and -independent colony formation, and CCDC67 expression suppressed tumorigenesis in nude mice. We suggest that CCDC67 is a putative tumor suppressor gene that is silenced in gastric cancers by promoter CpG methylation and that it may play an important role in cell signaling and migration related to tumorigenesis.

ZEB2 mediates multiple pathways regulating cell proliferation, migration, invasion, and apoptosis in glioma

BACKGROUND

The aim of the present study was to analyze the expression of Zinc finger E-box Binding homeobox 2 (ZEB2) in glioma and to explore the molecular mechanisms of ZEB2 that regulate cell proliferation, migration, invasion, and apoptosis.

METHODOLOGY/PRINCIPAL FINDINGS

Expression of ZEB2 in 90 clinicopathologically characterized glioma patients was analyzed by immunohistochemistry. Furthermore, siRNA targeting ZEB2 was transfected into U251 and U87 glioma cell lines in vitro and proliferation, migration, invasion, and apoptosis were examined separately by MTT assay, Transwell chamber assay, flow cytometry, and western blot.

RESULTS

The expression level of ZEB2 protein was significantly increased in glioma tissues compared to normal brain tissues (P<0.001). In addition, high levels of ZEB2 protein were positively correlated with pathology grade classification (P = 0.024) of glioma patients. Knockdown of ZEB2 by siRNA suppressed cell proliferation, migration and invasion, as well as induced cell apoptosis in glioma cells. Furthermore, ZEB2 downregulation was accompanied by decreased expression of CDK4/6, Cyclin D1, Cyclin E, E2F1, and c-myc, while p15 and p21 were upregulated. Lowered expression of ZEB2 enhanced E-cadherin levels but also inhibited β-Catenin, Vimentin, N-cadherin, and Snail expression. Several apoptosis-related regulators such as Caspase-3, Caspase-6, Caspase-9, and Cleaved-PARP were activated while PARP was inhibited after ZEB2 siRNA treatment.

CONCLUSION

Overexpression of ZEB2 is an unfavorable factor that may facilitate glioma progression. Knockdown ZEB2 expression by siRNA suppressed cell proliferation, migration, invasion and promoted cell apoptosis in glioma cells.

Potential tumor suppressor NESG1 as an unfavorable prognosis factor in nasopharyngeal carcinoma

Background

Recently we identified nasopharyngeal epithelium specific protein 1 (NESG1) as a potential tumor suppressor in nasopharyngeal carcinoma (NPC). The purpose of this study is to investigate the involvement of NESG1 in tumor progression and prognosis of human NPC.

Methodology/Principal Findings

NESG1 protein expression in NPC was examined. Survival analysis was performed using Kaplan-Meier method. The effect of NESG1 on cell proliferation, migration, and invasion were also investigated.

Results

NESG1 expression was downregulated in atypical hyperplasia and NPC samples compared to normal and squamous nasopharynx tissues. Reduced protein expression was negatively associated with the status of NPC progression. Patients with lower NESG1 expression had a shorter overall survival and disease-free time than did patients with higher NESG1 expression. Multivariate analysis suggested NESG1 expression as an independent prognostic indicator for NPC patient survival. Proliferation, migration, and invasion ability were significantly increased in cell lines following lentiviral-mediated shRNA suppression of NESG1 expression. Microarray analysis indicated that NESG1 participated in multiple pathways, including MAPK signaling and cell cycle regulation. Finally, DNA methylation microarray examination revealed a lack of hypermethylation at the NESG1 promoter, suggesting other mechanisms are involved in suppressing NESG1 expression in NPC.

Conclusion

Our studies are the first to demonstrate that decreased NESG1 expression is an unfavorable prognostic factor for NPC.

Matrix metalloproteinase 2 promotes cell growth and invasion in colorectal cancer

Colorectal cancer (CRC) is the third leading cause of cancer-related death in the western world. In this study, we evaluated the expression of matrix metalloproteinase 2 gene (MMP2) in CRC and analyzed its correlation with clinicopathological features. We found that the expression of MMP2 was significantly higher in CRC tissues than in the colorectal tissues. In addition, high levels of MMP2 protein were positively correlated with the status of tumor size, lymph node metastasis, distant metastasis, Dukes' stage, and tumor invasion. Moreover, patients with higher MMP2 levels had markedly shorter overall survivals than those with low MMP2 levels. Multivariate analysis results suggested that the level of MMP2 expression is an independent prognostic indicator for the survival of patients with CRC. Silencing MMP2 expression in CRC cell lines with lentiviral-mediated shRNA markedly suppressed cell proliferation, colony formation, and invasion. Furthermore, we observed that vascular endothelial growth factor (VEGF) and membrane type 1 (MT1)-MMP protein levels were decreased in MMP2-down-regulated colorectal cells. Therefore, our study demonstrated that MMP2 is an important factor related to carcinogenesis and metastasis of CRC, and MMP2 promotes CRC cell growth and invasion by up-regulating VEGF and MT1-MMP expression, which makes this pathway a potential target for cancer treatment.