Exosomal HMGA2 protein from EBV-positive NPC cells destroys vascular endothelial barriers and induces endothelial-to-mesenchymal transition to promote metastasis.

Increased vascular permeability facilitates metastasis. Cancer-secreted exosomes are emerging mediators of cancer-host crosstalk. Epstein-Barr virus (EBV), identified as the first human tumor-associated virus, plays a crucial role in metastatic tumors, especially in nasopharyngeal carcinoma (NPC). To date, whether and how exosomes from EBV-infected NPC cells affect vascular permeability remains unclear. Here, we show that exosomes from EBV-positive NPC cells, but not exosomes from EBV-negative NPC cells, destroy endothelial cell tight junction (TJ) proteins, which are natural barriers against metastasis, and promote endothelial-to-mesenchymal transition (EndMT) in endothelial cells. Proteomic analysis revealed that the level of HMGA2 protein was higher in exosomes derived from EBV-positive NPC cells compared with that in exosomes derived from EBV-negative NPC cells. Depletion of HMGA2 in exosomes derived from EBV-positive NPC cells attenuates endothelial cell dysfunction and tumor cell metastasis. In contrast, exosomes from HMGA2 overexpressing EBV-negative NPC cells promoted these processes. Furthermore, we showed that HMGA2 upregulates the expression of Snail, which contributes to TJ proteins reduction and EndMT in endothelial cells. Moreover, the level of HMGA2 in circulating exosomes is significantly higher in NPC patients with metastasis than in those without metastasis and healthy negative controls, and the level of HMGA2 in tumor cells is associated with TJ and EndMT protein expression in endothelial cells. Collectively, our findings suggest exosomal HMGA2 from EBV-positive NPC cells promotes tumor metastasis by targeting multiple endothelial TJ and promoting EndMT, which highlights secreted HMGA2 as a potential therapeutic target and a predictive marker for NPC metastasis.

Epstein-Barr Virus Induces Lymphangiogenesis and Lympth Node Metastasis via Upregulation of VEGF-C in Nasopharyngeal Carcinoma.

Lymphatic metastasis is a common clinical symptom in nasopharyngeal carcinoma (NPC), the most common Epstein-Barr virus (EBV)-associated head and neck malignancy. However, the effect of EBV on NPC lymph node (LN) metastasis is still unclear. In this study, we demonstrated that EBV infection is strongly associated with advanced clinical N stage and lymphangiogenesis of NPC. We found that NPC cells infected with EBV promote LN metastasis by inducing cancer-associated lymphangiogenesis, whereas these changes were abolished upon clearance of EBV genomes. Mechanistically, EBV-induced VEGF-C contributed to lymphangiogenesis and LN metastasis, and PHLPP1, a target of miR-BART15, partially contributed to AKT/HIF1a hyperactivity and subsequent VEGF-C transcriptional activation. In addition, administration of anti-VEGF-C antibody or HIF1α inhibitors attenuated the lymphangiogenesis and LN metastasis induced by EBV. Finally, we verified the clinical significance of this prometastatic EBV/VEGF-C axis by determining the expression of PHLPP1, AKT, HIF1a, and VEGF-C in NPC specimens with and without EBV. These results uncover a reasonable mechanism for the EBV-modulated LN metastasis microenvironment in NPC, indicating that EBV is a potential therapeutic target for NPC with lymphatic metastasis. IMPLICATIONS: This research demonstrates that EBV induces lymphangiogenesis in NPC by regulating PHLPP1/p-AKT/HIF1a/VEGF-C, providing a new therapeutic target for NPC with lymphatic metastasis.

A novel miR-200c/c-myc negative regulatory feedback loop is essential to the EMT process, CSC biology and drug sensitivity in nasopharyngeal cancer.

Overexpression of the c-Myc oncogene has been implicated in cancer stem cell - like (CSC) phenotypes and epithelial-to-mesenchymal transition (EMT) in cancer. However, the underlying molecular mechanism by which c-Myc regulates EMT and CSC potential in remains unclear. In the present study, we showed that the expression of c-Myc protein is inversely correlated with microRNA (miR)-200c expression in primary tumor samples from nasopharyngeal cancer (NPC) patients. We further demonstrated that Myc and miR-200c negatively regulate the expression each other in NPC cell lines. c-Myc transcriptionally repressed expression of miR-200c by directly binding to two E-box sites located within a 1 kb segment upstream of TSS of the miR-200c. In addition, miR-200c post-transcriptionally repressed expression of c-Myc by binding to its 3'-untranslated region, suggesting the existence of a negative feedback loop between Myc and miR-200c. Overexpression of c-Myc interfered with this feedback loop and activated the EMT program, induced CSC phenotypes, and enhanced drug sensitivity, whereas miR-200c could counteract these biological effects of c-Myc. Our results provide a novel mechanism governing c-Myc and miR-200c expression and indicate that either targeting c-Myc or restoring miR-200c expression would be a promising approach to overcome oncogenic role of c-Myc in NPC.

GenCLiP 3: mining human genes' functions and regulatory networks from PubMed based on co-occurrences and natural language processing.

SUMMARY: We present a web server, GenCLiP 3, which is an updated version of GenCLiP 2.0 to enhance analysis of human gene functions and regulatory networks, with the following improvements: i) accurate recognition of molecular interactions with polarity and directionality from the entire PubMed database; ii) support for Boolean search to customize multiple-term search and to quickly retrieve function related genes; iii) strengthened association between gene and keyword by a new scoring method; and iv) daily updates following literature release at PubMed FTP. AVAILABILITY: The server is freely available for academic use at: http://ci.smu.edu.cn/genclip3/. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Core pluripotency factors promote glycolysis of human embryonic stem cells by activating GLUT1 enhancer.

Human embryonic stem cells (hESCs) depend on glycolysis for energy and substrates for biosynthesis. To understand the mechanisms governing the metabolism of hESCs, we investigated the transcriptional regulation of glucose transporter 1 (GLUT1, SLC2A1), a key glycolytic gene to maintain pluripotency. By combining the genome-wide data of binding sites of the core pluripotency factors (SOX2, OCT4, NANOG, denoted SON), chromosomal interaction and histone modification in hESCs, we identified a potential enhancer of the GLUT1 gene in hESCs, denoted GLUT1 enhancer (GE) element. GE interacts with the promoter of GLUT1, and the deletion of GE significantly reduces the expression of GLUT1, glucose uptake and glycolysis of hESCs, confirming that GE is an enhancer of GLUT1 in hESCs. In addition, the mutation of SON binding motifs within GE reduced the expression of GLUT1 as well as the interaction between GE and GLUT1 promoter, indicating that the binding of SON to GE is important for its activity. Therefore, SON promotes glucose uptake and glycolysis in hESCs by inducing GLUT1 expression through directly activating the enhancer of GLUT1.

A miRNA-HERC4 pathway promotes breast tumorigenesis by inactivating tumor suppressor LATS1.

The E3 ligase HERC4 is overexpressed in human breast cancer and its expression levels correlated with the prognosis of breast cancer patients. However, the roles of HERC4 in mammary tumorigenesis remain unclear. Here we demonstrate that the knockdown of HERC4 in human breast cancer cells dramatically suppressed their proliferation, survival, migration, and tumor growth in vivo, while the overexpression of HERC4 promoted their aggressive tumorigenic activities. HERC4 is a new E3 ligase for the tumor suppressor LATS1 and destabilizes LATS1 by promoting the ubiquitination of LATS1. miRNA-136-5p and miRNA-1285-5p, expression of which is decreased in human breast cancers and is inversely correlated with the prognosis of breast cancer patients, are directly involved in suppressing the expression of HERC4. In summary, we discover a miRNA-HERC4-LATS1 pathway that plays important roles in the pathogenesis of breast cancer and represents new therapeutic targets for human breast cancer.

[Generation of a new strain of NOD/SCID/IL2Rγ-/- mice with targeted disruption of Prkdc and IL2Rγ genes using CRISPR/Cas9 system].

OBJECTIVE: The NOD/SCID/IL2Rγ- /- (NSG) mouse strain is the most widely used immunodeficient strain for xenograft transplantation. However, the existing SCID mutation is a spontaneous mutation of the Prkdc gene, which leads to leaky T cell developmental block and difficulty in genotyping. It is therefore important to develop a new strain of NSG mice with targeted disruption of Prkdc and IL2Rγ genes. METHODS: Targeted disruption of Prkdc and IL2Rγ genes was achieved using the CRISPR/Cas9 system. By intercrossing the knockout and NOD mice, we obtained a novel strain of NOD/SCID/IL2Rγ- /-(NSG) mice, denoted as cNSG (Chinese NSG) mice. RESULTS: In addition to the NOD mutation, cNSG mice exhibited a complete absence of T cells, B cells and NK cells. cNSG mice allowed more efficient engraftment of human cancer cells than the commonly used immunodeficient nude mice. CONCLUSION: cNSG mice will provide an important xenotransplantation model for biomedical research.

A novel three-dimensional tumorsphere culture system for the efficient and low-cost enrichment of cancer stem cells with natural polymers.

Cancer stem cells (CSCs) are considered to serve a key role in tumor progression, recurrence and metastasis. Tumorsphere culture is the most important method for enriching CSCs and is widely used in basic research and drug screening. However, the traditional suspension cell culture system has several disadvantages, including low efficiency, high cost and difficult procedure, making it difficult to produce tumorspheres on a large scale. In the present study, two biomaterials, methylcellulose (MC) and gellan gum (GG), were used to construct a novel culture system based on the traditional system. Subsequently, the characteristics of the novel three-dimensional (3D) culture system were evaluated, the design scheme was optimized, and the morphological and biological features of the tumorspheres cultured in this 3D system were compared with the traditional system. The results revealed that the tumorspheres cultured in the novel 3D system presented a higher seeding density and improved morphology, while maintaining stem-like properties. This evidence suggests that a simple, efficient and low-cost culture system that produces tumorspheres on a large scale was successfully constructed, which can be widely used in various aspects of stem cell research.

Sulforaphane inhibits cancer stem-like cell properties and cisplatin resistance through miR-214-mediated downregulation of c-MYC in non-small cell lung cancer.

We herein report that sulforaphane (SFN), a potent anti-cancer and well-tolerated dietary compound, inhibits cancer stem-like cell (CSC) properties and enhances therapeutic efficacy of cisplatin in human non-small cell lung cancer (NSCLC). SFN exerted these functions through upregulation of miR-214, which in turn targets the coding region of c-MYC. This finding was further corroborated by our observations that plasmid or lentiviral vector-mediated expression of 3'UTR-less c-MYC cDNA and cisplatin- or doxorubicin-induced endogenous c-MYC accumulation was similarly suppressed by either SFN or miR-214. Further, we showed that the reported inhibitory effects of SFN on ß-catenin are also mediated by miR-214. SFN/miR-214 signaling inhibited CSC properties and enhanced the cytotoxicity of chemotherapeutic drugs in vitro. Experiments with nude mice carrying xenograft tumors showed that SFN sensitized NSCLC cells to cisplatin's efficacy, which is accompanied by inhibition of cisplatin-induced c-MYC accumulation in tumor tissues. Our results provided strong evidence and mechanisms to support consideration of SFN or synthetic derivatives as a therapeutic agent in combination with cisplatin for the treatment of patients with NSCLC and, potentially, other types of c-MYC-addicted tumors.

ERP44 inhibits human lung cancer cell migration mainly via IP3R2.

Cancer cell migration is involved in tumour metastasis. However, the relationship between calcium signalling and cancer migration is not well elucidated. In this study, we used the human lung adenocarcinoma A549 cell line to examine the role of endoplasmic reticulum protein 44 (ERP44), which has been reported to regulate calcium release inside of the endoplasmic reticulum (ER), in cell migration. We found that the inositol 1,4,5-trisphosphate receptors (IP3Rs/ITPRs) inhibitor 2-APB significantly inhibited A549 cell migration by inhibiting cell polarization and pseudopodium protrusion, which suggests that Ca2+ is necessary for A549 cell migration. Similarly, the overexpression of ERP44 reduced intracellular Ca2+ release via IP3Rs, altered cell morphology and significantly inhibited the migration of A549 cells. These phenomena were primarily dependent on IP3R2 because wound healing in A549 cells with IP3R2 rather than IP3R1 or IP3R3 siRNA was markedly inhibited. Moreover, the overexpression of ERP44 did not affect the migration of the human neuroblastoma cell line SH-SY5Y, which mainly expresses IP3R1. Based on the above observations, we conclude that ERP44 regulates A549 cell migration mainly via an IP3R2-dependent pathway.

The important role of the receptor for activated C kinase 1 (RACK1) in nasopharyngeal carcinoma progression.

BACKGROUND: The receptor for activated C kinase 1 (RACK1) is involved in various cancers, but its roles in nasopharyngeal carcinoma (NPC) have not yet been fully elucidated. METHODS: Initially, RACK1 expression was analyzed by immunohistochemistry in NPC and normal nasopharyngeal (NP) tissues. It was also detected by qPCR and Western blot in NPC cells. Confocal microscope and immunofluorescence were performed to detect the subcellular compartmentalization of RACK1. Subsequently, after up- or down-regulating RACK1 in NPC cells, cell proliferation and migration/invasion were tested using in vitro assays including MTT, EdU, colony formation, Transwell and Boyden assays. Furthermore, several key molecules were detected by Western blot to explore underlying mechanism. Finally, clinical samples were analyzed to confirm the relationship between RACK1 expression and clinical features. RESULTS: Receptor for activated C kinase 1 expression was much higher in NPC than NP tissues. And RACK1 was mainly located in the cytoplasm. Overexpression of RACK1 promoted NPC cell proliferation and metastasis/invasion, whereas depletion of this protein suppressed NPC cell proliferation and metastasis/invasion. Mechanistically, RACK1 deprivation obviously suppressed the activation of Akt and FAK, suggesting the PI3K/Akt/FAK pathway as one of functional mechanisms of RACK1 in NPC. Furthermore, clinical sample analysis indicated a positive correlation between in vivo expression of RACK1 with lymph node invasion and clinical stage of NPC. CONCLUSION: Our results demonstrate that RACK1 protein plays an important role in NPC development and progression. The upregulation of RACK1 can promote the proliferation and invasion of NPC by regulating the PI3K/Akt/FAK signal pathway. Thus, this study contributes to the discovery of a potential therapeutic target for NPC.

[Expressions of short palate, lung and nasal epithelium clone 1 in different human tissues].

OBJECTIVE: To examine the expression patterns of short palate, lung and nasal epithelium clone 1 (SPLUNC1) gene in human tissues. METHODS: In situ hybridization was used to detect the expression of SPLUNC1 gene in 37 different human tissues. RESULTS: We found that SPLUNC1 gene was not expressed in squamous epithelial cells of the palate, epidermis, esophagus, or the esophagus-cardia junction, metaplastic squamous cells in the nasopharynx, trachea, or uterus cervix, or tumor cells of esophageal squamous cell carcinoma or lung squamous cell carcinoma. SPLUNC1 gene was not expressed in the single layer columnar epithelia cells in the stomach, gallbladder, jejunum, colon, endometrium, or uterus cervix. SPLUNC1 expression was detected mainly in pseudostratified columnar epithelial cells in the nasopharynx, trachea and bronchi, and was gradually down-regulated from the upper to lower end of the respiratory tract, but was not detected in the lung tissues. SPLUNC1 expression was detected not only in the duct and serous gland cells in the parotid and submandibular glands, but also in cells of submucosal serous glands in the nasopharynx and lung, but not in the cells of the mucosal glands. The parietal cells of the gastric submucosa and epithelial cells of the lobula and ducts of the mammary glands expressed SPLUNC1. The adenocarcinoma cells in the lung, stomach, colon, mammary gland, uterus endometrium and cervix showed strong expressions of SPLUNC1 gene. CONCLUSION: SPLUNC1 expression is highly cell-specific in association with the cell functions.

Berberine Increases Doxorubicin Sensitivity by Suppressing STAT3 in Lung Cancer.

Berberine (BBR), an alkaloid component isolated from Chinese medicinal herb Huang Lian, has aroused broad interests for its antitumor effect in recent years. The signal transducer and activator of transcription 3 (STAT3), plays critical roles in malignant transformation and progression and was found to be constitutively activated in a variety of human cancers. In this study, we show that BBR inhibited cell proliferation, induced apoptosis, and suppressed tumor spheroid formation of lung cancer cell lines. These effects were correlated with BBR-mediated suppression of both phosphorylated and total levels of STAT3 protein. Furthermore, BBR promoted STAT3 degradation by enhancing ubiquitination. Importantly, we demonstrated that BBR was able to inhibit doxorubicin (DOX)-mediated STAT3 activation and sensitize lung cancer cells to the cytotoxic effect of DOX treatment. Given that BBR is widely used in clinic with low toxicity, our results are potentially important for the development of a novel combinatorial therapy with BBR and DOX in the treatment of lung cancer.

Hes1 triggers epithelial-mesenchymal transition (EMT)-like cellular marker alterations and promotes invasion and metastasis of nasopharyngeal carcinoma by activating the PTEN/AKT pathway.

Overexpression of the transcriptional factor Hes1 (hairy and enhancer of split-1) has been observed in numerous cancers, but the precise roles of Hes1 in epithelial-mesenchymal transition (EMT), cancer invasion and metastasis remain unknown. Our current study firstly revealed that Hes1 upregulation in a cohort of human nasopharyngeal carcinoma (NPC) biopsies is significantly associated with the EMT, invasive and metastatic phenotypes of cancer. In the present study, we found that Hes1 overexpression triggered EMT-like cellular marker alterations of NPC cells, whereas knockdown of Hes1 through shRNA reversed the EMT-like phenotypes, as strongly supported by Hes1-mediated EMT in NPC clinical specimens described above. Gain-of-function and loss-of-function experiments demonstrated that Hes1 promoted the migration and invasion of NPC cells in vitro. In addition, exogenous expression of Hes1 significantly enhanced the metastatic ability of NPC cells in vivo. Chromatin immunoprecipitation (ChIP) assays showed that Hes1 inhibited PTEN expression in NPC cells through binding to PTEN promoter region. Increased Hes1 expression and decreased PTEN expression were also observed in a cohort of NPC biopsies. Additional studies demonstrated that Hes1-induced EMT-like molecular changes and increased motility and invasion of NPC cells were mediated by PTEN. Taken together, our results suggest, for what we believe is the first time, that Hes1 plays an important role in the invasion and metastasis of NPC through inhibiting PTEN expression to trigger EMT-like phenotypes.

Cytokine-induced killer cells efficiently kill stem-like cancer cells of nasopharyngeal carcinoma via the NKG2D-ligands recognition.

Cancer stem cells (CSCs) are considered to be the root cause for cancer treatment failure. Thus, there remains an urgent need for more potent and safer therapies against CSCs for curing cancer. In this study, the antitumor activity of cytokine-induced killer (CIK) cells against putative CSCs of nasopharyngeal carcinoma (NPC) was fully evaluated in vitro and in vivo. To visualize putative CSCs in vitro by fluorescence imaging, and image and quantify putative CSCs in tumor xenograft-bearing mice by in vivo bioluminescence imaging, NPC cells were engineered with CSC detector vector encoding GFP and luciferase (Luc) under control of Nanog promoter. Our study reported in vitro intense tumor-killing activity of CIK cells against putative CSCs of NPC, as revealed by percentage analysis of side population cells, tumorsphere formation assay and Nanog-promoter-GFP-Luc reporter gene strategy plus time-lapse recording. Additionally, time-lapse imaging firstly illustrated that GFP-labeled or PKH26-labeled putative CSCs or tumorspheres were usually attacked simultaneously by many CIK cells and finally killed by CIK cells, suggesting the necessity of achieving sufficient effector-to-target ratios. We firstly confirmed that NKG2D blockade by anti-NKG2D antibody significantly but partially abrogated CIK cell-mediated cytolysis against putative CSCs. More importantly, intravenous infusion of CIK cells significantly delayed tumor growth in NOD/SCID mice, accompanied by a remarkable reduction in putative CSC number monitored by whole-body bioluminescence imaging. Taken together, our findings suggest that CIK cells demonstrate the intense tumor-killing activity against putative CSCs of NPC, at least in part, by NKG2D-ligands recognition. These results indicate that CIK cell-based therapeutic strategy against CSCs presents a promising and safe approach for cancer treatment.

MicroRNA-19 triggers epithelial-mesenchymal transition of lung cancer cells accompanied by growth inhibition.

The miR-19 family (miR-19a and miR-19b-1) are key oncogenic components of the miR-17-92 cluster. Overexpression of miR-19 is strongly associated with cancer invasion and metastasis, and poor prognosis of cancer patients. However, the underlying mechanisms remain largely unknown. In the present study, we found that enforced expression of miR-19 including miR-19a and miR-19b-1 triggered epithelial-mesenchymal transition (EMT) of lung cancer cells A549 and HCC827 as shown by mesenchymal-like morphological conversion, downregulation of epithelial proteins (e.g., E-cadherin, ZO-1 (zona occludens 1), and α-catenin), upregulation of mesenchymal proteins (e.g., vimentin, fibronectin 1, N-cadherin, and snail1), formation of stress fibers, and reduced cell adhesion. In addition, enhanced migration and invasion were observed in the cancer cells A549 and HCC827 undergoing EMT. In contrast, silencing of endogenous miR-19 reversed EMT and reduced the migration and invasion abilities of A549 and HCC827 cells. DNA microarray results revealed significant changes of the expression of genes related to EMT, migration, and metastasis of miR-19-expressing A549 cells. Moreover, siRNA-mediated knockdown of PTEN, a target of miR-19, also resulted in EMT, migration, and invasion of A549 and HCC827 cells, suggesting that PTEN is involved in miR-19-induced EMT, migration and invasion of lung cancer cells. Furthermore, lung cancer cells undergoing EMT induced by miR-19 demonstrated reduced proliferation in vitro and in vivo, and enhanced resistance to apoptosis caused by TNF-α. Taken together, these findings suggest that miR-19 triggers EMT, which has an important role in the invasion and migration of lung cancer cells, accompanied by the reduced proliferation of cells.

MicroRNA-122 triggers mesenchymal-epithelial transition and suppresses hepatocellular carcinoma cell motility and invasion by targeting RhoA.

The loss of microRNA-122 (miR-122) expression is strongly associated with increased invasion and metastasis, and poor prognosis of hepatocellular carcinoma (HCC), however, the underlying mechanisms remain poorly understood. In the present study, we observed that miR-122 over-expression in HCC cell lines Sk-hep-1 and Bel-7402 triggered the mesenchymal-epithelial transition (MET), as demonstrated by epithelial-like morphological changes, up-regulated epithelial proteins (E-cadherin, ZO-1, α-catenin, occludin, BVES, and MST4), and down-regulated mesenchymal proteins (vimentin and fibronectin). The over-expression of miRNA-122 also caused cytoskeleton disruption, RhoA/Rock pathway inactivation, enhanced cell adhesion, and suppression of migration and invasion of Sk-hep-1 and Bel-7402 cells, whereas, these effects could be reversed through miR-122 inhibition. Additional studies demonstrated that the inhibition of wild-type RhoA function induced MET and inhibited cell migration and invasion, while RhoA over-expression reversed miR-122-induced MET and inhibition of migration and invasion of HCC cells, suggesting that miR-122 induced MET and suppressed the migration and invasion of HCC cells by targeting RhoA. Moreover, our results demonstrated that HNF4α up-regulated its target gene miR-122 that subsequently induced MET and inhibited cell migration and invasion, whereas miR-122 inhibition reversed these HNF4α-induced phenotypes. These results revealed functional and mechanistic links among the tumor suppressors HNF4α, miR-122, and RhoA in EMT and invasive and metastatic phenotypes of HCC. Taken together, our study provides the first evidence that the HNF4α/miR-122/RhoA axis negatively regulates EMT and the migration and invasion of HCC cells.

GenCLiP 2.0: a web server for functional clustering of genes and construction of molecular networks based on free terms.

UNLABELLED: Identifying biological functions and molecular networks in a gene list and how the genes may relate to various topics is of considerable value to biomedical researchers. Here, we present a web-based text-mining server, GenCLiP 2.0, which can analyze human genes with enriched keywords and molecular interactions. Compared with other similar tools, GenCLiP 2.0 offers two unique features: (i) analysis of gene functions with free terms (i.e. any terms in the literature) generated by literature mining or provided by the user and (ii) accurate identification and integration of comprehensive molecular interactions from Medline abstracts, to construct molecular networks and subnetworks related to the free terms. AVAILABILITY AND IMPLEMENTATION: http://ci.smu.edu.cn. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Cancer stem cell characteristics, ALDH1 expression in the invasive front of nasopharyngeal carcinoma.

The invasive tumor front underlies the biological aggressiveness and epithelial-mesenchymal transition (EMT) in various human malignances. However, the molecular and biological characteristics of invasive tumor front in NPC have rarely been described. Additionally, the features of cancer stem cells (CSCs) in the invasive front of tumors and its correlation with EMT also remain elusive. Our study was to investigate the expression of CSCs marker aldehyde dehydrogenase 1 (ALDH1) in the invasive front of nasopharyngeal carcinoma (NPC) and its clinical significance. Immunohistochemistry was mainly used to detect ALDH1 expression in the invasive front of NPC. The relationship between ALDH1 expression and EMT-associated markers was also examined. ALDH1 expression in the invasive front correlated strongly with lymphatic invasion (p<0.001), T classification (p=0.001), M classification (p<0.001), clinical stage (p<0.001), and local recurrence (p=0.008). ALDH1 overexpression in the invasive front contributed to worse survival of NPC, particularly in patients with early stage (T1-T2 or N0-N1) (p<0.001 and p=0.002, respectively), though it was not an independent prognostic factor (p=0.196). Furthermore, in the invasive front of NPC, ALDH1 expression correlated significantly with EMT-related biomarkers E-cadherin (p=0.026), Vimentin (p<0.001), Periostin (p<0.001), and Snail (p<0.001), but not with ß-catenin (p=0.143). Our findings demonstrate first that ALDH1 expression in the invasive front links closely with EMT characteristics and tumor aggressiveness, which might provide a useful prognostic marker for NPC patients.

Nuclear ß-catenin accumulation is associated with increased expression of Nanog protein and predicts poor prognosis of non-small cell lung cancer.

BACKGROUND: Although the prognostic roles of ß-catenin expression in non-small cell lung cancer (NSCLC) have been reported in several immunohistochemical (IHC) studies, the results were not consistent because some studies lack sufficient number of the positive cases or did not evaluate the subcellular localization features of the protein. METHOD: In this study, we have evaluated the expression levels and subcellular localization of ß-catenin and Nanog proteins IHC staining in tissue specimens from 309 patients with NSCLC, and explored their association with clinicopathological features and patient outcome. RESULTS: We showed that patients with negative expression of membranous beta-catenin had a trend towards shorter survival (p=0.064) than those with positive expression. In contrast to previous studies, we found that increased expression of either cytoplasmic or nuclear ß-catenin was strongly associated with poor prognosis and was an independent prognosticator for overall survival (p <0.01). We further found that NSCLC cells frequently exhibited an abundance of nuclear Nanog protein which was significantly correlated with nuclear ß-catenin expression (p <0.01) and poor prognosis (p <0.01). Interestingly, immunofluorescent staining results revealed that increased expression of Nanog and nuclear translocation of ß-catenin occurred concomitantly in response to epidermal growth factor receptor(EGFR) signaling in A549 and H23 cells. Furthermore, western blot analysis show that nuclear ß-catenin rather than cytoplasmic ß-catenin expression in the A549 and H23 cells can be enhanced by adding EGF, Nanog expression in the A549 and H23 cells with knockdown of ß-catenin can not be obviously enhanced by adding EGF. CONCLUSION: We propose that evaluation of subcellular localization of ß-catenin and Nanog expression is of clinical significance for patients with NSCLC.