Expression and prognostic significance of EFNB2 and EphB4 genes in patients with oesophageal squamous cell carcinoma

Tyrosine Phosphorylation Profiling Revealed the Signaling Network Characteristics of CAMKK2 in Gastric Adenocarcinoma

Calcium/calmodulin-dependent protein kinase kinase 2 (CAMKK2) is a serine/threonine protein kinase which functions via the calcium-triggered signaling cascade with CAMK1, CAMK4, and AMPKα as the immediate downstream substrates. CAMKK2 is reported to be overexpressed in gastric cancer; however, its signaling mechanism is poorly understood. We carried out label-free quantitative tyrosine phosphoproteomics to investigate tyrosine-mediated molecular signaling associated with CAMKK2 in gastric cancer cells. Using a high-resolution Orbitrap Fusion Tribrid Fourier-transform mass spectrometer, we identified 350 phosphotyrosine sites mapping to 157 proteins. We observed significant alterations in 81 phosphopeptides corresponding to 63 proteins upon inhibition of CAMKK2, among which 16 peptides were hyperphosphorylated corresponding to 13 proteins and 65 peptides were hypophosphorylated corresponding to 51 proteins. We report here that the inhibition of CAMKK2 leads to changes in the phosphorylation of several tyrosine kinases such as PKP2, PTK2, EPHA1, EPHA2, PRKCD, MAPK12, among others. Pathway analyses revealed that proteins are differentially phosphorylated in response to CAMKK2 inhibition involved in focal adhesions, actin cytoskeleton, axon guidance, and signaling by VEGF. The western blot analysis upon inhibition and/or silencing of CAMKK2 revealed a decrease in phosphorylation of PTK2 at Y925, c-JUN at S73, and STAT3 at Y705, which was in concordance with the mass spectrometry data. The study indicates that inhibition of CAMKK2 has an anti-oncogenic effect in gastric cells regulating phosphorylation of STAT3 through PTK2/c-JUN in gastric cancer.

Ephrin B Activate Src Family Kinases in Fibroblasts Inducing Stromal Remodeling in Prostate Cancer

Through stromal-epithelial interactions, carcinoma associated fibroblasts (CAF) play a critical role in tumor growth and progression. Activation of erythrophoyetin-producing human hepatocellular (Eph) receptors has been implicated in cancer. Eph receptor interactions with Ephrin ligands lead to bidirectional signals in the recipient and effector cells. The consequences of continuous reverse Ephrin signaling activation in fibroblasts on prostate cancer (PCa) is unknown. When compared to benign prostate fibroblast, CAF displayed higher expression of Ephrin B1, B2, and B3 ligands (EFNB1, EFNB2, and EFNB3). In this study, we found that continuous activation of EFNB1 and EFNB3 in a benign human prostate stromal cell line (BHPrS1) increased the expression of CAF markers and induced a CAF phenotype. BHPrS1EFNB1 and BHPrS1EFNB3 displayed a pro-tumorigenic secretome with multiple effects on neovascularization, collagen deposition, and cancer cell proliferation, overall increasing tumorigenicity of a premalignant prostate epithelial cell line BPH1 and PCa cell line LNCaP, both in vitro and in vivo. Inhibition of Src family kinases (SFK) in BHPrS1EFNB1 and BHPrS1EFNB3 suppressed EFNB-induced ɑ-SMA (Alpha-smooth muscle actin) and TN-C (Tenascin-C) in vitro. Our study suggests that acquisition of CAF characteristics via SFK activation in response to increased EFNB ligands could promote carcinogenesis via modulation of TME in PCa.

The potential roles of p53 signaling reactivation in pancreatic cancer therapy

Globally, pancreatic cancer (PC) is a common and highly malignant gastrointestinal tumor that is characterized by an insidious onset and ready metastasis and recurrence. Over recent decades, the incidence of PC has been increasing on an annual basis; however, the pathogenesis of this condition remains enigmatic. PC is not sensitive to radio- or chemotherapy, and except for early surgical resection, there is no curative treatment regime; consequently, the prognosis for patients with PC is extremely poor. Transcription factor p53 is known to play key roles in many important biological processes in vertebrates, including normal cell growth, differentiation, cell cycle progression, senescence, apoptosis, metabolism, and DNA damage repair. However, there is a significant paucity of basic and clinical studies to describe how p53 gene mutations or protein dysfunction facilitate the occurrence, progression, invasion, and resistance to therapy, of malignancies, including PC. Herein, we describe the involvement of p53 signaling reactivation in PC treatment as well as its underlying molecular mechanisms, thereby providing useful insights for targeting p53-related signal pathways in PC therapy.

OSov: An Interactive Web Server to Evaluate Prognostic Biomarkers for Ovarian Cancer

Simple Summary

The OSov web server incorporates gene expression profiles with clinical risk factors to estimate the ovarian cancers patients’ survival, and provides a tool for multiple analysis, such as forest-plot, uni/multi-variate survival analysis, Kaplan-Meier plot and nomogram construction.

Abstract

Ovarian cancer is one of the most aggressive and highly lethal gynecological cancers. The purpose of our study is to build a free prognostic web server to help researchers discover potential prognostic biomarkers by integrating gene expression profiling data and clinical follow-up information of ovarian cancer. We construct a prognostic web server OSov (Online consensus Survival analysis for Ovarian cancer) based on RNA expression profiles. OSov is a user-friendly web server which could present a Kaplan–Meier plot, forest plot, nomogram and survival summary table of queried genes in each individual cohort to evaluate the prognostic potency of each queried gene. To assess the performance of OSov web server, 163 previously published prognostic biomarkers of ovarian cancer were tested and 72% of them had their prognostic values confirmed in OSov. It is a free and valuable prognostic web server to screen and assess survival-associated biomarkers for ovarian cancer.

Salivary biomarkers in oral squamous cell carcinoma

In disease diagnostics and health surveillance, the use of saliva has potential because its collection is convenient and noninvasive. Over the past two decades, the development of salivary utilization for the early detection of cancer, especially oral cavity and oropharynx cancer has gained the interest of the researcher and clinician. Until recently, the oral cavity and oropharynx cancers are still having a five-year survival rate of 62%, one of the lowest in all major human cancers. More than 90% of oral cancers are oral squamous cell carcinoma (OSCC). Despite the ease of accessing the oral cavity in clinical examination, most OSCC lesions are not diagnosed in the early stage, which is suggested to be the main cause of the low survival rate. Many studies have been performed and reported more than 100 potential saliva biomarkers for OSCC. However, there are still obstacles in figuring out the reliable OSCC salivary biomarkers and the clinical application of the early diagnosis protocol. The current review article discusses the emerging issues and is hoped to raise awareness of this topic in both researchers and clinicians. We also suggested the potential salivary biomarkers that are reliable, specific, and sensitive for the early detection of OSCC.

EphrinB2 expression in prostate adenocarcinoma: Implications for targeted therapy

BACKGROUND

Prostate cancer is managed by surgery, androgen deprivation and cytotoxic chemotherapy. Targeted therapy is emerging as an important pillar in cancer therapeutics, however, efficacy in prostate cancer has been limited. Eph-ephrin is a novel pathway that is upregulated in prostate cancer and promotes the initiation and progression of cancer. The aim of this study was to determine the immunohistochemical expression of ephrinB2 in prostate adenocarcinoma.

METHODS

A tissue microarray comprising of prostate adenocarcinoma of different grade groups was stained with a monoclonal anti-ephrinB2 antibody (Abcam, AB201512). The tumor and endothelial cells expressing the ephrinB2 positivity were noted. The statistical analysis was performed to determine the difference in expression based on grade groups and the TNM stage.

RESULTS

EphrinB2 was expressed in 40 out of 72 cases (55.5 %) of prostate adenocarcinoma and was predominantly negative in the normal prostatic tissue. There was no significant difference in the expression of ephrinB2 in various grade groups (p = 0.7) or stages (p = 0.6).

CONCLUSIONS

EphrinB2 is expressed in a significant number of prostate adenocarcinoma regardless of grade and stage. Hence, there is a potential to target this molecule in the low-grade tumors with localized disease as well as high grade, high volume tumors with metastatic disease.

EFNB2 facilitates cell proliferation, migration, and invasion in pancreatic ductal adenocarcinoma via the p53/p21 pathway and EMT

Ephrin-2 (EFNB2) is expressed at abnormally high levels in some neoplasms, such as squamous cell carcinoma of the head and neck and colorectal cancer. Its overexpression is associated with the malignant progression of tumors. However, the expression of EFNB2 in pancreatic ductal adenocarcinoma (PDAC) has not been thoroughly studied. EFNB2 expression was evaluated by quantitative real-time PCR, immunohistochemistry, and western blotting. Furthermore, the association between its expression levels and the clinicopathological features of PDAC patients was explored. To determine the underlying mechanisms of EFNB2, we transfected PDAC cells with small interfering RNA and performed in vitro and in vivo experiments. EFNB2 expression levels were significantly increased in cancer tissues and were associated with PDAC clinical stage and Ki67 expression. The down-regulation of EFNB2 inhibited cell proliferation by up-regulating p53/p21-mediated G0/G1 phase blockade. Knockdown of EFNB2 decreased the migration and invasion of PDAC cells by blocking epithelial-mesenchymal transition. These results suggested that EFNB2 may participate in the development of PDAC by promoting cell proliferation, migration, and invasion. Thus, EFNB2 is a potential target for the diagnosis and treatment of PDAC.

Expression levels of EPHB4, EFNB2 and caspase-8 are associated with clinicopathological features and progression of esophageal squamous cell cancer

The upregulation of EPH receptor B4 (EPHB4) results in a survival advantage for tumor cells via the inhibition of the casapse-8-mediated apoptotic pathway, which begins from the cell membrane. The present study investigated the expression patterns of EPHB4, ephrin B2 (EFNB2) and caspase-8 in patients with esophageal squamous cell carcinoma (ESCC). The association between the expression patterns and certain clinicopathological characteristics of the patients was also determined. mRNA levels of EPHB4, EFNB2 and caspase-8 in paired primary ESCC samples and adjacent esophageal tissues collected from 96 patients with ESCC were quantified using quantitative PCR. Upregulation of EPHB4 and EFNB2 mRNA expression, and downregulation of caspase-8 mRNA were detected in ESCC samples compared with that in the adjacent esophageal tissues. The expression levels of EPHB4 and EFNB2 were positively correlated with each other, whereas the mRNA levels of both EPHB4 and EFNB2 exhibited a negative correlation with that of caspase-8. The mRNA levels of both EPHB4 and EFNB2 demonstrated a significant positive association with certain clinicopathological features of patients with ESCC, including family history, tumor size, metastasis and stage. Conversely, a negative association was revealed between the expression level of caspase-8 and clinicopathological features of patients with ESCC. Moreover, mRNA expression levels of EPHB4 and EFNB2 were negatively associated with survival times of patients with ESCC, whereas the level of caspase-8 was positively associated with patient outcome. The results from the present study suggested that EPHB4, EFNB2 and caspase-8 may be implicated in the tumorigenesis and progression of ESCC, and that consequently, they may serve as useful prognostic markers, as well as potential therapeutic targets.

Exploring the FGFR3-related oncogenic mechanism in bladder cancer using bioinformatics strategy

Background

Aberrant activation of fibroblast growth factor receptor 3 (FGFR3) is frequently observed in bladder cancer, but how it involved in carcinogenesis is not well understood. The current study was aimed to investigate the underlying mechanism on the progression of bladder cancer.

Methods

The GSE41035 dataset downloaded from Gene Expression Omnibus was used to identify the differentially expressed genes (DEGs) between bladder cancer cell line RT112 with or without depletion of FGFR3, and gene ontology enrichment analysis was performed. Then, FGFR3-centered protein–protein interaction (PPI) and regulatory networks were constructed. Combined with the data retrieved from GSE31684, prognostic makers for bladder cancer were predicted.

Results

We identified a total of 2855 DEGs, and most of them were associated with blood vessel morphogenesis and cell division. In addition, KIAA1377, POLA2, FGFR3, and EPHA4 were the hub genes with high degree in the FGFR3-centered PPI network. Besides, 17 microRNAs (miRNAs) and 6 transcriptional factors (TFs) were predicted to be the regulators of the nodes in PPI network. Moreover, CSTF2, POLA1, HMOX2, and EFNB2 may be associated with the prognosis of bladder cancer patient.

Conclusions

The current study may provide some insights into the molecular mechanism of FGFR3 as a mediator in bladder cancer.

Ephrin-B2 overexpression predicts for poor prognosis and response to therapy in solid tumors

Ephrin B2 is variably expressed on tumor cells and its blockade has been shown to inhibit angiogenesis in animal models of pancreatic, colorectal, lung and head, and neck squamous cell carcinomas. However, the implications of ephrinB2 expression in cancer patients have remained elusive. In this study, we analyzed the cancer genome atlas (TCGA) for ephrinB2 expression. We report significant correlations between EFNB2 expression, overall survival and disease-free survival in head and neck squamous cell carcinoma (HNSCC, n = 519), pancreatic adenocarcinoma (n = 186), and bladder urothelial carcinoma (n = 410). In HNSCC patients, high-EFNB2 mRNA expression was associated with tumor HPV negativity, oral cavity location, alcohol intake, higher TP53 mutation, and EGFR amplification. EphrinB2 overexpression also correlated with worse response to chemotherapy and radiotherapy. The therapeutic potential of blocking ephrinB2 was validated in HNSCC patient-derived tumor xenografts and showed significant improvement in survival and tumor growth delay. Our data shows that ephrinB2 overexpression can serve as a critical biomarker for patient prognosis and response to therapy. These results should guide design of future clinical trials exploring EphrinB2 inhibition in cancer patients. © 2016 Wiley Periodicals, Inc.

An Omics Perspective on Molecular Biomarkers for Diagnosis, Prognosis, and Therapeutics of Cholangiocarcinoma

Cholangiocarcinoma (CCA) is an aggressive biliary tract malignancy arising from the epithelial bile duct. The lack of early diagnostic biomarkers as well as therapeutic measures results in severe outcomes and poor prognosis. Thus, effective early diagnostic, prognostic, and therapeutic biomarkers are required to improve the prognosis and prolong survival rates in CCA patients. Recent advancement in omics technologies combined with the integrative experimental and clinical validations has provided an insight into the underlying mechanism of CCA initiation and progression as well as clues towards novel biomarkers. This work highlights the discovery and validation of molecular markers in CCA identified through omics approaches. The possible roles of these molecules in various cellular pathways, which render CCA carcinogenesis and progression, will also be discussed. This paper can serve as a reference point for further investigations to yield deeper understanding in the complex feature of this disease, potentially leading to better approaches for diagnosis, prognosis, and therapeutics.

Expression of Eph A4, Eph B2 and Eph B4 receptors in AML

Eph receptors represent the largest subfamily of receptor tyrosine kinases (RTKs). The up- regulation of Eph receptors has been documented in various solid tumors, where it often correlates with poor prognosis. Their significance in hematologic malignancies is still unclear. This study aimed to investigate the expression of Eph A4, Eph B2, and Eph B4 mRNA in non - M3 AML patients and determine their prognostic significance. Bone marrow samples from 101 newly diagnosed non - M3 AML patients and 26 healthy controls for comparison were quantified by real time reverse transcriptase polymerase chain reaction (RT-PCR), and the comparative cycle threshold (Ct) method was used to determine their relative expression levels to GUS control gene. The results showed that expression of all selected Eph receptors was significantly lower in AML patients comparing to controls. It also differed according to FAB subtypes. The decreased expression levels of Eph A4 were associated with higher leukocytes (p = 0.022) and blast cell counts (p = 0.001), and unfavorable FLT3-ITD mutation. Our study revealed significant correlation between lower EphB2 expression levels, and higher complete remission rate (p = 0.009724) and longer overall survival. Additionally, we found that patients with shorter RFS had decreased EphB4 expression (p = 0.00). In conclusion, the results suggest the prognostic impact of decreased expression levels of some Eph receptors in AML patients.

Complementary expression and repulsive signaling suggest that EphB2 and ephrin-B1 are possibly involved in epithelial boundary formation at the squamocolumnar junction in the rodent stomach

Eph receptors and ephrin ligands are cell-cell communication molecules with well-defined roles in cell adhesion, migration, and tissue boundary formation. However, their expression levels in the squamocolumnar epithelial junction region at the distal esophagus are completely unknown. We examined EphB2 and ephrin-B1 localization in the squamocolumnar epithelial junction region between the proximal and distal stomach of the rodents. Immunostaining showed complimentary expression patterns along the proximal-to-distal axis of the gastric epithelia across the junction: EphB2 expression was maximal around the epithelial junction and sharply decreased in the stratified squamous epithelium at a short distance from the junction, whereas ephrin-B1 was strongly expressed in the stratified squamous epithelium at a distance from the junction and sharply decreased toward the junction. These expression patterns suggest that EphB2/ephrin-B1 signaling occurs preferentially in the epithelia across the junction, where the receptor and ligand expression highly overlap. We also show that (1) EphB2 preferentially binds ephrin-B1, and (2) cell repulsion/lateral migration was induced in primary cultured gastric keratinocytes on ephrin-B1-Fc- and EphB2-Fc-coated surfaces. On the basis of these findings, we propose that EphB2 and ephrin-B1 are possibly involved in epithelial boundary formation at the squamocolumnar junction.

The Eph/Ephrin family in cancer metastasis: communication at the service of invasion

Cancer cells rely on intercellular communication throughout the different stages of their transformation and progression into metastasis. They do so by co-opting different processes such as cell-cell junctions, growth factors, receptors, and vesicular release. Initially characterized in neuronal and vascular tissues, Ephs and Ephrins, the largest family of receptor tyrosine kinases, comprised of two classes (i.e., A and B types), is increasingly scrutinized by cancer researchers. These proteins possess the particular features of both the receptors and ligands being membrane-bound which, via mandatory direct cell-cell interactions, undergo a bidirectional signal transduction initiated from both the receptor and the ligand. Following cell-cell interactions, Ephs/Ephrins behave as guidance molecules which trigger both repulsive and attractive signals, so as to direct the movement of cells through their immediate microenvironment. They also direct processes which include sorting and positioning and cytoskeleton rearrangements, thus making them perfect candidates for the control of the metastatic process. In fact, the role of Ephs and Ephrins in cancer progression has been demonstrated for many of the family members and they, surprisingly, have both tumor promoter and suppressor functions in different cellular contexts. They are also able to coordinate between multiple processes including cell survival, proliferation, differentiation, adhesion, motility, and invasion. This review is an attempt to summarize the data available on these Ephs/Ephrins' biological functions which contribute to the onset of aggressive cancers. I will also provide an overview of the factors which could explain the functional differences demonstrated by Ephs and Ephrins at different stages of tumor progression and whose elucidation is warranted for any future therapeutic targeting of this signaling pathway in cancer metastasis.

Novel strategy for selection of monoclonal antibodies against highly conserved antigens: phage library panning against ephrin-B2 displayed on yeast

Ephrin-B2 is predominately expressed in endothelium of arterial origin, involved in developmental angiogenesis and neovasculature formation through its interaction with EphB4. Despite its importance in physiology and pathological conditions, it has been challenging to produce monoclonal antibodies against ephrin-B2 due to its high conservation in sequence throughout human and rodents. Using a novel approach for antibody selection by panning a phage library of human antibody against antigens displayed in yeast, we have isolated high affinity antibodies against ephrin-B2. The function of one high affinity binder (named as ‘EC8’) was manifested in its ability to inhibit ephrin-B2 interaction with EphB4, to cross-react with murine ephrin-B2, and to induce internalization into ephrin-B2 expressing cells. EC8 was also compatible with immunoprecipitation and detection of ephrin-B2 expression in the tissue after standard chemical fixation procedure. Consistent with previous reports on ephrin-B2 induction in some epithelial tumors and tumor-associated vasculatures, EC8 specifically detected ephrin-B2 in tumors as well as the vasculature within and outside of the tumors. We envision that monoclonal antibody developed in this study may be used as a reagent to probe ephrin-B2 distribution in normal as well as in pathological conditions and to antagonize ephrin-B2 interaction with EphB4 for basic science and therapeutic applications.

Cytoplasmic ezrin and moesin correlate with poor survival in head and neck squamous cell carcinoma

Members of the 4.1 superfamily of proteins, including ezrin, moesin, merlin, and willin regulate many normal physiologic processes such as cellular shape, motility, and proliferation. In addition, they contribute both to tumor development and tumor progression. We reported previously that strong cytoplasmic ezrin expression was independently associated with poorer patient survival. One hundred and thirty-one histologically confirmed primary head and neck squamous cell carcinomas were examined prospectively for cancer progression and survival at a large health care center in the Bronx, NY, USA. Immunohistochemical analysis of ezrin, moesin, merlin, and willin expression in tissue microarray samples of primary head and neck squamous cell carcinoma revealed a significant association of increased cytoplasmic ezrin with poor cancer survival. Global RNA analyses suggest that cancers with high cytoplasmic ezrin have a more invasive phenotype. This study supports our previous findings associating cytoplasmic ezrin with more aggressive behavior and poorer outcome and indicates the need for a multi-institutional study to validate the use of cytoplasmic ezrin as a biomarker for treatment planning in head and neck squamous cell carcinoma.

Clinical relevance of Ephs and ephrins in cancer: lessons from breast, colorectal, and lung cancer profiling

Pre-clinical studies provide compelling evidence that members of the Eph family of receptor tyrosine kinases and their ephrin ligands promote tumor growth, invasion and metastasis, and neovascularization. Tumor suppressive roles have also been reported for the receptors, and ligand-dependent versus ligand-independent signaling has emerged as one key mechanism underlying tumor suppressive function as opposed to oncogenic effects. Determining how these observations relate to clinical outcome is a crucial step for translating the biological and mechanistic data into new molecularly targeted therapies. Expression profiling in human patient samples bridges this gap and provides valuable clinical relevance to laboratory observations. In addition to analyses performed using privately assembled patient tumor samples, publically available microarray datasets and tissue microarrays linked to clinical data have emerged as tractable tools for addressing the clinical relevance of specific molecules and families of related molecules. This review summarizes the clinical relevance of specific Eph and ephrin molecules in human breast, colorectal, and lung cancers.

Genome-wide expression patterns associated with oncogenesis and sarcomatous transdifferentation of cholangiocarcinoma

Background

The molecular mechanisms of CC (cholangiocarcinoma) oncogenesis and progression are poorly understood. This study aimed to determine the genome-wide expression of genes related to CC oncogenesis and sarcomatous transdifferentiation.

Methods

Genes that were differentially expressed between CC cell lines or tissues and cultured normal biliary epithelial (NBE) cells were identified using DNA microarray technology. Expressions were validated in human CC tissues and cells.

Results

Using unsupervised hierarchical clustering analysis of the cell line and tissue samples, we identified a set of 342 commonly regulated (>2-fold change) genes. Of these, 53, including tumor-related genes, were upregulated, and 289, including tumor suppressor genes, were downregulated (<0.5 fold change). Expression of SPP1, EFNB2, E2F2, IRX3, PTTG1, PPARγ, KRT17, UCHL1, IGFBP7 and SPARC proteins was immunohistochemically verified in human and hamster CC tissues. Additional unsupervised hierarchical clustering analysis of sarcomatoid CC cells compared to three adenocarcinomatous CC cell lines revealed 292 differentially upregulated genes (>4-fold change), and 267 differentially downregulated genes (<0.25 fold change). The expression of 12 proteins was validated in the CC cell lines by immunoblot analysis and immunohistochemical staining. Of the proteins analyzed, we found upregulation of the expression of the epithelial-mesenchymal transition (EMT)-related proteins VIM and TWIST1, and restoration of the methylation-silenced proteins LDHB, BNIP3, UCHL1, and NPTX2 during sarcomatoid transdifferentiation of CC.

Conclusion

The deregulation of oncogenes, tumor suppressor genes, and methylation-related genes may be useful in identifying molecular targets for CC diagnosis and prognosis.

Study of abnormal chromosome regions in esophageal squamous cell carcinoma by comparative genomic hybridization: relationship of lymph node metastasis and distant metastasis to selected abnormal regions

Squamous cell carcinoma of the esophagus (ESCC) has a poor prognosis among digestive tract cancers. Lymph node metastasis and distant metastasis are the major factors determining its prognosis. We used comparative genomic hybridization (CGH) to evaluate primary tumor lymph nodes and metastatic areas from ESCC patients in order to determine the relationship between abnormal chromosome regions and outcome. Tumor tissues and lymph nodes were collected from 51 patients with ESCC, and abnormal chromosome regions were detected by CGH. We searched for regions that were significantly more common in patients with lymph nodes metastases (n>/= 6) or distant metastases, and correlated those chromosomal changes with survival. Regions showing amplification in more than 65% of esophageal squamous cell cancers were as follows: 17q12 (90.2%), 17q21 (86.3%), 3q29 (82.4%), 3q28 (78.4%), 8q24.2 (76.5%), 22q12 (76.5%), 3q27 (74.5%), 8q24.3 (74.5%), 1q22 (70.6%), 5p15.3 (70.6%), 22q13 (70.6%), 3q26.3, 8q23, 8q24.1, 9q34, 11q13, 17p12, 17q25, 20q12, 20q13.1 (68.6%), 1q32, 1q42, and 20q13.2 (66.7%). Regions showing deletion in more than 50% of the tumors were as follows: Yp11.3 (62.7%), 3p26 (56.9%), Yq12 (54.9%), 13q21 (52.9%), 4q32 (51.0%), and 13q22 (51.0%). When Fisher's test was used to assess associations of these regions with metastases to lymph nodes, amplification at 2q12-14 (P= 0.012), 3q24-26 (P= 0.005), and 7q21-31 (P= 0.026) were significant. Survival was worse for patients with amplification at all 3 regions. In patients with distant organ metastases, amplification at 7p13-21 was significant (P= 0.008), and survival was worse. Chromosomal amplifications in ESCC at 2q12-14, 3q24-26, and 7q21-31 were associated with lymph node metastasis, while amplification at 7p13-21 was related to distant metastasis. Amplification at these regions correlated with worse survival. Genes involved in the phenotype of ESCC may exist in these regions. Identification of these genes is a theme for future investigation.

Ephrin-B2 regulates endothelial cell morphology and motility independently of Eph-receptor binding

The transmembrane protein ephrin-B2 regulates angiogenesis, i.e. the formation of new blood vessels through endothelial sprouting, proliferation and remodeling processes. In addition to essential roles in the embryonic vasculature, ephrin-B2 expression is upregulated in the adult at sites of neovascularization, such as tumors and wounds. Ephrins are known to bind Eph receptor family tyrosine kinases on neighboring cells and trigger bidirectional signal transduction downstream of both interacting molecules. Here we show that ephrin-B2 dynamically modulates the motility and cellular morphology of isolated endothelial cells. Even in the absence of Eph-receptor binding, ephrin-B2 stimulates repeated cycling between actomyosin-dependent cell contraction and spreading episodes, which requires the presence of the C-terminal PDZ motif. Our results show that ephrin-B2 is a potent regulator of endothelial cell behavior, and indicate that the control of cell migration and angiogenesis by ephrins might involve both receptor-dependent and receptor-independent activities.

Ephrin expression and function in cancer

Ephrins are cell membrane-associated signaling proteins bound by transmembrane Eph receptors on juxtaposed cells. Eph-ephrin interactions result in bidirectional signaling within both receptor- and ligand-bearing cells, with diverse consequences for cell morphology and behavior. Such interactions are especially important during early vertebrate development, and growing evidence has revealed equally important roles in adult-tissue homeostasis. As for the Eph receptors, abnormal expression of ephrins is associated with disease, especially cancer. The ephrins have received less attention than the Ephs in the literature, owing, in part, to their later discovery and that they are fewer in number. Here, we attempt to redress this imbalance and provide an 'ephrin-centric' discussion of the expression and function of ephrins in cancer.

The phosphorylation of ephrin-B2 ligand promotes glioma cell migration and invasion

To reveal molecular drivers of glioma invasion, two distinct glioblastoma (GBM) cell phenotypes (invading cells and tumor core cells) were collected from 19 GBM specimens using laser capture microdissection. Isolated RNA underwent whole human genome expression profiling to identify differentially expressed genes. Pathway enrichment analysis highlighted the bidirectional receptor/ligand tyrosine kinase system, EphB/ephrin-B, as the most tightly linked system to the invading cell phenotype. Clinical relevance of ephrin-B genes was confirmed in a clinically annotated expression data set of 195 brain biopsy specimens. Levels of ephrin-B1 and -B2 mRNA were significantly higher in GBM (n = 82) than in normal brain (n = 24). Kaplan-Meier analysis demonstrated ephrin-B2, but not ephrin-B1, expression levels were significantly associated with short term survival in malignant astrocytomas (n = 97, p = 0.016). In human brain tumor specimens, the production and phosphorylation of ephrin-B2 were high in GBM. Immunohistochemistry demonstrated ephrin-B2 localization primarily in GBM cells but not in normal brain. A highly invasive glioma cell line, U87, expressed high levels of ephrin-B2 compared with relatively less invasive cell lines. Treatment with EphB2/Fc chimera further enhanced migration and invasion of U87 cells, whereas treatment with an ephrin-B2 blocking antibody significantly slowed migration and invasion. Forced expression of ephrin-B2 in the U251 cell line stimulated migration and invasion in vitro and ex vivo, concomitant with tyrosine phosphorylation of ephrin-B2. These results demonstrate that high expression of ephrin-B2 is a strong predictor of short-term survival and that ephrin-B2 plays a critical role in glioma invasion rendering this signaling pathway as a potential therapeutic target.

Microarray-based response prediction in esophageal adenocarcinoma

PURPOSE

In locally advanced (uT(3), N(+)) adenocarcinomas of the esophagus, neoadjuvant chemotherapy improves patient outcome. However, only a subgroup of patients responds. Therefore, in the present study, we evaluated whether the response to neoadjuvant chemotherapy can be predicted by a pretreatment tumor biopsy analysis.

EXPERIMENTAL DESIGN

Biopsies of 47 patients with locally advanced (uT(3), N(+)) adenocarcinoma of the esophagus were obtained during primary staging. All patients underwent neoadjuvant chemotherapy with cisplatin, 5-fluorouracil, and leucovorin and subsequent resection of the esophagus. Biopsies were used for microarray analysis. The predominance of tumor cells within the specimens was >70%. Affymetrix U133 plus 2.0 gene chips with 54675 probe sets were used. A statistical comparison of patients responding to chemotherapy versus nonresponding patients was done. All patients were examined with immunohistology against Ephrin B3 receptor and Ki-67.

RESULTS

A total of 86 genes were at least 2-fold differentially regulated comparing responding with nonresponding adenocarcinomas of the esophagus. The predominant genes encoded for the regulation of the cell cycle, transduction, translation, cell-cell interaction, cytoskeleton, and the signal transduction. The strongest difference was seen for the Ephrin B3 receptor. This result could be confirmed by immunhistology. A statistical significant correlation between the Ephrin B3 receptor, chemotherapy response, pathologic staging, and grading could be shown.

CONCLUSIONS

There were significant differences in the gene profile between patients with adenocarcinoma of the esophagus responding to neoadjuvant chemotherapy compared with nonresponding patients. This suggests that it could be possible to characterize patients responding to chemotherapy even before starting the treatment using customized microarray analysis.

Genomic-wide analysis of lymphatic metastasis-associated genes in human hepatocellular carcinoma

AIM: To identify the genes related to lymph node metastasis in human hepatocellular carcinoma (HCC), 32 HCC patients with or without lymph node metastasis were investigated by high-throughput microarray comprising 886 genes.

METHODS: The samples of cancerous and non-cancerous paired tissue were taken from 32 patients with HCC who underwent hepatectomy with lymph node dissection. Total RNA was extracted from the cells obtained by means of laser microdissection (LCM) and was amplified by the T7-based amplification system. Then, the amplified samples were applied in the cDNA microarray comprising of 886 genes.

RESULTS: The results demonstrated that 25 up-regulated genes such as cell membrane receptor, intracellular signaling and cell adhesion related genes, and 48 down-regulated genes such as intracellular signaling and cell cycle regulator-related genes, were correlated with lymph node metastasis in HCC. Amongst them were included some interesting genes, such as MET, EPHA2, CCND1, MMP2, MMP13, CASP3, CDH1, and PTPN2. Expression of 16 genes (MET, CCND1, CCND2, VEGF, KRT18, RFC4, BIRC5, CDC6, MMP2, BCL2A1, CDH1, VIM, PDGFRA, PTPN2, SLC25A5 and DSP) were further confirmed by real-time quantitative reverse transcriptional polymerase chain reaction (RT-PCR).

CONCLUSION: Tumor metastasis is an important biological characteristic, which involves multiple genetic changes and cumulation. This genome-wide information contributes to an improved understanding of molecular alterations during lymph node metastasis in HCC. It may help clinicians to predict metastasis of lymph nodes and assist researchers in identifying novel therapeutic targets for metastatic HCC patients.