Higher expression of EphA2 and ephrin-A1 is related to favorable clinicopathological features in pathological stage I non-small cell lung carcinoma

Comprehensive analysis of EphA2 in pan-cancer: A prognostic biomarker associated with cancer immunity

BACKGROUND

Several studies have reported a significant relationship between Ephrin receptor A2 (EphA2) and malignant progression in numerous cancers. However, there is a lack of comprehensive pan-cancer analysis on the prognostic value, mutation status, methylation landscape, and potential immunological function of EphA2.

METHOD

Using The Cancer Genome Atlas, Genotype Tissue Expression Database and GEO data, we analysed the differences in EphA2 expression between normal and tumour tissues and the effects of EphA2 on the prognosis of different tumours. Furthermore, using GSCALite, cBioPortal, TISDB, ULCLAN and TIMER 2.0 databases or platforms, we comprehensively analysed the potential oncogenic mechanisms or manifestations of EphA2 in 33 different tumour types, including tumour mutation status, DNA methylation status and immune cell infiltration. The correlation of EphA2 with immune checkpoints, tumour mutational burden, DNA microsatellite instability and DNA repair genes was also calculated. Finally, the effects of EphA2 inhibitors on the proliferation of human glioma and lung cancer cells were verified in cellular experiments.

RESULTS

EphA2 is differentially expressed in different tumours, and patients with overexpression have poorer overall survival. In addition, gene mutations, gene copy number variation and DNA/RNA methylation of EphA2 have been identified in various tumours. Moreover, EphA2 is positively associated with immune infiltration involving macrophages and CD8+ T cells. Further, EphA2 mRNA expression is significantly associated with immune checkpoint in various cancers, especially programmed death-ligand 1. Finally, the EphA2 inhibitor ALW-II-41-27 shows potent anti-tumour activity.

CONCLUSION

Our first pan-cancer study of EphA2 provides insight into the prognostic and immunological roles of EphA2 in different tumours, suggesting that EphA2 might be a potential biomarker for poor prognosis and immune infiltration in cancer.

Vasculogenic mimicry score identifies the prognosis and immune landscape of lung adenocarcinoma

Background: Lung cancer has a high incidence and mortality rate worldwide. Vasculogenic mimicry (VM) is a specific modality of tumor angiogenesis that could potentially be a new target for tumor therapy. The purpose of this study was to explore the role of VM-related genes in assessing the prognosis and immune landscape of lung cancer. Methods: VM-related genes were obtained from previous studies, and the expression data and clinical data of lung adenocarcinoma (LUAD) patients were obtained from the TCGA database and GEO database. We performed enrichment analysis of 24 VM-related genes and screened hub genes by constructing a protein-protein interaction network and using Cytoscape software. Subsequently, we developed the VM score based on univariate Cox regression analysis and Lasso analysis and validated the VM score on the GSE72094 dataset. In addition, we constructed a nomogram based on the VM score in the TCGA cohort. Finally, we explored the correlation between the VM score and the tumor microenvironment, immune cell infiltration, immune checkpoints, and drug sensitivity. Results: Enrichment analysis revealed that VM-related genes were associated with the HIF signaling pathway and angiogenic pathway. We developed a VM score based on 3 genes (EPHA2, LAMC2 and LOXL2) in LUAD patients. Kaplan-Meier analysis showed that the VM score was associated with poor prognosis in LUAD patients. The receiver operating characteristic curve suggested that the VM score and nomogram are valid predictors for the overall survival of LUAD patients. The VM score was significantly correlated with immune cell infiltration, such as naïve B cells, neutrophils, and eosinophils, and there was a difference in the TME between the high VM score group and the low VM score group. LUAD patients in the high VM score group were more sensitive to antitumor drugs. Conclusion: In summary, the VM score developed in this study is a valuable indicator for evaluating the prognosis and immune landscape of LUAD patients. VM may be a potential target for antitumor therapy in lung cancer.

May EPH/Ephrin Targeting Revolutionize Lung Cancer Treatment?

Lung cancer (LC) is the leading cause of cancer death in the United States. Erythropoietin-producing hepatocellular receptors (EPHs) comprise the largest receptor tyrosine kinases (RTKs) family in mammals. EPHs along with their ligands, EPH-family receptor-interacting proteins (ephrins), have been found to be either up- or downregulated in LC cells, hence exhibiting a defining role in LC carcinogenesis and tumor progression. In their capacity as membrane-bound molecules, EPHs/ephrins may represent feasible targets in the context of precision cancer treatment. In order to investigate available therapeutics targeting the EPH/ephrin system in LC, a literature review was conducted, using the MEDLINE, LIVIVO, and Google Scholar databases. EPHA2 is the most well-studied EPH/ephrin target in LC treatment. The targeting of EPHA2, EPHA3, EPHA5, EPHA7, EPHB4, EPHB6, ephrin-A1, ephrin-A2, ephrin-B2, and ephrin-B3 in LC cells or xenograft models not only directly correlates with a profound LC suppression but also enriches the effects of well-established therapeutic regimens. However, the sole clinical trial incorporating a NSCLC patient could not describe objective anti-cancer effects after anti-EPHA2 antibody administration. Collectively, EPHs/ephrins seem to represent promising treatment targets in LC. However, large clinical trials still need to be performed, with a view to examining the effects of EPH/ephrin targeting in the clinical setting.

Restored microRNA-519a enhances the radiosensitivity of non-small cell lung cancer via suppressing EphA2

Accumulating evidence has demonstrated that microRNA-519a (miR-519a) acts as the tumor suppressor in various cancers, but little is known regarding its intrinsic regulatory mechanisms in non-small cell lung cancer (NSCLC). Here, we aimed to investigate the role of miR-519a-targeted ephrinA2 receptor (EphA2) in radiosensitivity of NSCLC. MiR-519a and EphA2 expression in NSCLC and paracancerous tissues were detected using RT-qPCR and western blot analysis. A549 cell line was cultured and radiation-resistant cell line A549R was constructed using fractionated X-ray irradiation of these cells at 60 Gy. Colony formation ability and radioresistance of parent strain A549 and resistant strain A549R were detected with restored miR-519a and depleted EphA2. MTT assay was used to measure cell proliferation, flow cytometry was performed for determination of cell cycle distribution and apoptosis. The migration and invasion abilities were assessed by Transwell assay. The target relationship between miR-519a and EphA2 was verified. Results suggested that miR-519a was downregulated and EphA2 was upregulated in NSCLC tissues and cells, and miR-519a targeted EphA2. MiR-519a expression declined, while EphA2 expression elevated in A549R cells versus A549 cells. Upregulated miR-519a and downregulated EphA2 suppressed D0, Dq, survival fraction (SF2) and N-value, arrested cells at G0/G1 phase, advanced the apoptosis and attenuated migration, proliferation, and invasion of A549 and A549R cells. Overexpression of EphA2 reversed the promotion of upregulated miR-519a on radiosensitivity of NSCLC cells. Our results revealed that miR-519a enhances radiosensitivity of NSCLC by inhibiting EphA2 expression. Moreover, miR-519a serves as a target for NSCLC treatment.

Waldenström Macroglobulinemia: Mechanisms of Disease Progression and Current Therapies

Waldenström macroglobulinemia is an indolent, B-cell lymphoma without a known cure. The bone marrow microenvironment and cytokines both play key roles in Waldenström macroglobulinemia (WM) tumor progression. Only one FDA-approved drug exists for the treatment of WM, Ibrutinib, but treatment plans involve a variety of drugs and inhibitors. This review explores avenues of tumor progression and targeted drug therapy that have been investigated in WM and related B-cell lymphomas.

EFNA3 as a predictor of clinical prognosis and immune checkpoint therapy efficacy in patients with lung adenocarcinoma

BACKGROUND

Ephrin receptors (Eph) and their ligands, called ephrins, function in various disease processes. However, the expression level and prognostic value of Eph/ephrins in lung adenocarcinoma (LUAD) are still unclear.

METHODS

The Oncomine and GEPIA databases were used to explore the differential expression of Eph/ephrins in LUAD. Kaplan-Meier plotter was selected to explore the prognostic value of Eph/ephrins. The cBioPortal database was used to analyze the genetic variation of the EFNA3 gene. Immunohistochemistry was used to analyze the expression level and clinical value of ephrin-A3 protein in clinical LUAD tissue. Weighted coexpression network analysis (WGCNA) and gene set enrichment analysis (GSEA) identified the potential regulatory mechanism of EFNA3. CCK-8 assays and colony-forming experiments were used to investigate whether EFNA3 can regulate cell proliferation ability in LUAD. Analysis of lactate, ATP, and glucose uptake levels was used to explore the effect of EFNA3 on glycolysis ability. In addition, we investigated the relationship between EFNA3 and tumor infiltrating immune cells (TIICs). Finally, the potential immunotherapy response prediction value of EFNA3 was also explored.

RESULTS

In this study, we found that EFNA3 expression was significantly correlated with both overall survival (OS) and progression-free survival (PFS) in LUAD patients based on a comprehensive analysis of the Eph/Ephrin family. Next, the expression of the EFNA3 protein was increased in LUAD tissues and was designated an independent prognostic risk factor. Mechanistically, EFNA3 may be involved in nuclear division, synaptic function, and ion channel activity-related pathways. In vitro experiments confirmed the role of EFNA3 in promoting LUAD cells and showed that it could regulate glycolytic capacity. Moreover, EFNA3 was negatively associated with immunity, stromal infiltration, and several TIICs. Finally, EFNA3 was found to be positively related to multiple immunotherapy biomarkers.

CONCLUSIONS

In conclusion, increased EFNA3 in LUAD patients predicted worse clinical prognosis, promoted LUAD cell proliferation and glycolysis ability, and was related to immunotherapy response.

The Clinical Impact of the EPH/Ephrin System in Cancer: Unwinding the Thread

Erythropoietin-producing human hepatocellular receptors (EPHs) compose the largest known subfamily of receptor tyrosine kinases (RTKs). They bind and interact with the EPH family receptor interacting proteins (ephrins). EPHs/ephrins are implicated in a variety of physiological processes, as well as in cancer pathogenesis. With neoplastic disease remaining a leading cause of death world-wide, the development of novel biomarkers aiding in the field of diagnosis, prognosis, and disease monitoring is of utmost importance. A multitude of studies have proven the association between the expression of members of the EPH/ephrin system and various clinicopathological parameters, including disease stage, tumor histologic grade, and patients' overall survival. Besides their utilization in timely disease detection and assessment of outcome, EPHs/ephrins could also represent possible novel therapeutic targets. The aim of the current review of the literature was to present the existing data regarding the association between EPH/ephrin system expression and the clinical characteristics of malignant tumors.

Oncogenic functions and therapeutic targeting of EphA2 in cancer

More than 25 years of research and preclinical validation have defined EphA2 receptor tyrosine kinase as a promising molecular target for clinical translation in cancer treatment. Molecular, genetic, biochemical, and pharmacological targeting strategies have been extensively tested in vitro and in vivo, and drugs like dasatinib, initially designed to target SRC family kinases, have been found to also target EphA2 activity. Other small molecules, therapeutic targeting antibodies, and peptide-drug conjugates are being tested, and more recently, approaches harnessing antitumor immunity against EphA2-expressing cancer cells have emerged as a promising strategy. This review will summarize preclinical studies supporting the oncogenic role of EphA2 in breast cancer, lung cancer, glioblastoma, and melanoma, while delineating the differing roles of canonical and noncanonical EphA2 signaling in each setting. This review also summarizes completed and ongoing clinical trials, highlighting the promise and challenges of targeting EphA2 in cancer.

Targeting EphA2 in Bladder Cancer Using a Novel Antibody-Directed Nanotherapeutic

Ephrin receptor A2 (EphA2) is a member of the Ephrin/Eph receptor cell-to-cell signaling family of molecules, and it plays a key role in cell proliferation, differentiation, and migration. EphA2 is overexpressed in a broad range of cancers, and its expression is in many cases associated with poor prognosis. We recently developed a novel EphA2-targeting antibody-directed nanotherapeutic encapsulating a labile prodrug of docetaxel (EphA2-ILs-DTXp) for the treatment of EphA2-expressing malignancies. Here, we characterized the expression of EphA2 in bladder cancer using immunohistochemistry in 177 human bladder cancer samples and determined the preclinical efficacy of EphA2-ILs-DTXp in four EphA2-positive patient-derived xenograft (PDX) models of the disease, either as a monotherapy, or in combination with gemcitabine. EphA2 expression was detected in 80–100% of bladder cancer samples and correlated with shorter patient survival. EphA2 was found to be expressed in tumor cells and/or tumor-associated blood vessels in both primary and metastatic lesions with a concordance rate of approximately 90%. The EphA2-targeted antibody-directed nanotherapeutic EphA2-ILs-DTXp controlled tumor growth, mediated greater regression, and was more active than free docetaxel at equitoxic dosing in all four EphA2-positive bladder cancer PDX models. Combination of EphA2-ILs-DTXp and gemcitabine in one PDX model led to improved tumor growth control compared to monotherapies or the combination of free docetaxel and gemcitabine. These data demonstrating the prevalence of EphA2 in bladder cancers and efficacy of EphA2-ILs-DTXp in PDX models support the clinical exploration of EphA2 targeting in bladder cancer.

Role of EFNA1 in tumorigenesis and prospects for cancer therapy

Cancer is one of the major threats to human health. It is of vital importance to reveal the mechanisms of tumorigenesis, identify effective biomarkers and develop novel treatments to improve patient outcome. EFNA1 (ephrinA1) is a member of the EFN family, and it has been studied extensively since its discovery in 1990. Increasing evidence indicates that EFNA1 plays a pivotal role in the pathogenesis of tumors. We provide a detailed overview of the expression and prognostic value of EFNA1 in different types of human malignancies. We briefly discuss the mechanisms of EFNA1 induction in hypoxic environments and its pro-angiogenic function in different cancer cells. We describe the effects of EFNA1 on tumor growth, invasiveness and metastasis. We summarize recent advances in EFNA1-associated cancer therapeutics with emphasis on the prospect of novel anti-tumor methods based on EFNA1.

Effect of EphA2 knockdown on melanoma metastasis depends on intrinsic ephrinA1 level

PURPOSE

Upregulation of receptor tyrosine kinase EphA2 has been found to be associated with a poor prognosis in many types of cancer and is considered an attractive therapeutic target. As yet, few efforts have been focused on its tumor suppressive activity triggered by its ligand, ephrinA1. Here, we aimed to determine the potential of ephrinA1 as an important player in melanoma metastasis.

METHODS

Data from the Cancer Genome Atlas (TCGA) and the Cancer Cell Line Encyclopedia (CCLE) were analyzed to explore the expression and prognostic implications of EphA2 and ephrinA1 in melanoma. Western blotting, shRNA, colony formation and immunofluorescence assays, as well as two in vivo xenograft models (subcutaneous and metastatic) were used to evaluate the role of EphA2 in melanoma progression. Akt inhibition and ephrinA1-Fc were used to confirm the influence of Akt activation and ephrinA1 levels on the EphA2 effects. Immunohistochemistry (IHC) was performed on xenograft and patient melanoma tissues.

RESULTS

We found that high levels of ephrinA1, but not EphA2, were negatively correlated with melanoma metastasis. The expression levels of EphA2 and ephrinA1 were not correlated. After EphA2 downregulation, colony forming abilities and lung metastatic growth were reduced in melanoma cell lines with a low ephrinA1 expression, but were increased in melanoma cell lines with a high ephrinA1 expression. EphA2-mediated colony formation in EphA2-high/ephrinA1-low cells was found to be Akt-dependent and to be inhibited by the addition of ephrinA1-Fc. IHC staining of primary melanoma specimens revealed that EphA2-high/ephrinA1-low patients exhibited poorer outcomes than EphA2-high/ephrinA1-high patients.

CONCLUSIONS

From our data we conclude that evaluation of ephrinA1 levels may be helpful for the application of EphA2-targeted therapies and for prognostic predictions in melanoma patients.

Formulation optimization of an ephrin A2 targeted immunoliposome encapsulating reversibly modified taxane prodrugs

Ephrin A2 targeted immunoliposomes incorporating pH-sensitive taxane prodrugs were developed for sustained delivery of active drug to solid tumors. Here we describe the systematic formulation development and characterization of these immunoliposomes. We synthesized both paclitaxel and docetaxel prodrugs to formulate as ephrin A2-targeted liposomes stabilized in the aqueous core with sucroseoctasulfate (SOS). The optimized lipid formulation was comprised of egg-sphingomyelin, cholesterol, and polyethylene glycol distearoyl glycerol (PEG-DSG). The formulations examined had a high efficiency of prodrug encapsulation (as high as 114 mol% taxane per mole phospholipid) and subsequent stability (>3 years at 2-8 °C). The taxane prodrug was stabilized with extraliposomal citric acid and subsequently loaded into liposomes containing a gradient of SOS, resulting in highly stable SOS-drug complexes being formed inside the liposome. The internal prodrug and SOS concentrations were optimized for their impact on in vivo drug release and drug degradation. Cryo-electron microscope images revealed dense prodrug-SOS complex in the aqueous core of the immunoliposomes. Ephrin A2-targeted taxane liposomes exhibited sub-nanomolar (0.69 nM) apparent equilibrium dissociation constant toward the extracellular domain of the ephrin A2 receptor, long circulation half-life (8-12 h) in mouse plasma, a release rate dependent on intraliposomal drug concentration and stable long-term storage. At an equitoxic dose of 50 mg taxane/kg, ephrin A2-targeted liposomal prodrug showed greater antitumor activity than 10 mg/kg of docetaxel in A549 non-small cell lung, as well as MDA-MB-436 and SUM149 triple negative breast cancer xenograft models. The lead molecule entered a Phase I clinical trial in patients with solid tumors (NCT03076372).

Roles of EphA1/A2 and ephrin-A1 in cancer

The biological functions of the Eph/ephrin system have been intensively investigated and well documented so far since its discovery in 1987. Although the Eph/ephrin system has been implicated in pathological settings such as Alzheimer's disease and cancer, the molecular mechanism of the Eph/ephrin system in those diseases is not well understood. Especially in cancer, recent studies have demonstrated that most of Eph and ephrin are up‐ or down‐regulated in various types of cancer, and have been implicated in tumor progression, tumor malignancy, and prognosis. However, they lack consistency and are in controversy. The localization patterns of EphA1 and EphA2 in mouse lungs are very similar, and both knockout mice showed similar phenotypes in the lungs. Ephrin‐A1 that is a membrane‐anchored ligand for EphAs was co‐localized with EphA1 and EphA2 in lung vascular endothelial cells. We recently uncovered the molecular mechanism of ephrin‐A1‐induced lung metastasis by understanding the physiological function of ephrin‐A1 in lungs. This review focuses on the function of EphA1, EphA2, and ephrin‐A1 in tumors and an establishment of pre‐metastatic microenvironment in the lungs.

Differential Expression Patterns of Eph Receptors and Ephrin Ligands in Human Cancers

Eph receptors constitute the largest family of receptor tyrosine kinases, which are activated by ephrin ligands that either are anchored to the membrane or contain a transmembrane domain. These molecules play important roles in the development of multicellular organisms, and the physiological functions of these receptor-ligand pairs have been extensively documented in axon guidance, neuronal development, vascular patterning, and inflammation during tissue injury. The recognition that aberrant regulation and expression of these molecules lead to alterations in proliferative, migratory, and invasive potential of a variety of human cancers has made them potential targets for cancer therapeutics. We present here the involvement of Eph receptors and ephrin ligands in lung carcinoma, breast carcinoma, prostate carcinoma, colorectal carcinoma, glioblastoma, and medulloblastoma. The aberrations in their abundances are described in the context of multiple signaling pathways, and differential expression is suggested as the mechanism underlying tumorigenesis.

Targeting focal adhesion kinase overcomes erlotinib resistance in smoke induced lung cancer by altering phosphorylation of epidermal growth factor receptor

EGFR-based targeted therapies have shown limited success in smokers. Identification of alternate signaling mechanism(s) leading to TKI resistance in smokers is critically important. We observed increased resistance to erlotinib in H358 NSCLC (non-small cell lung carcinoma) cells chronically exposed to cigarette smoke (H358-S) compared to parental cells. SILAC-based mass-spectrometry approach was used to study altered signaling in H358-S cell line. Importantly, among the top phosphosites in H358-S cells we observed hyperphosphorylation of EGFR (Y1197) and non-receptor tyrosine kinase FAK (Y576/577). Supporting these observations, a transcriptomic-based pathway activation analysis of TCGA NSCLC datasets revealed that FAK and EGFR internalization pathways were significantly upregulated in smoking patients, compared to the never-smokers and were associated with elevated PI3K signaling and lower level of caspase cascade and E-cadherin pathways activation. We show that inhibition of FAK led to decreased cellular proliferation and invasive ability of the smoke-exposed cells, and restored their dependency on EGFR signaling. Our data suggests that activation of focal adhesion pathway significantly contributes to erlotinib resistance, and that FAK is a potential therapeutic target for management of erlotinib resistance in smoke-induced NSCLC.

Increased expression of EphA2 and E-N cadherin switch in primary hepatocellular carcinoma

Aim

To investigate the expression and clinical significance of ephrin type-A receptor 2 and epithelial-mesenchymal transition-related proteins in primary hepatocellular carcinoma.

Methods

Tissues from 52 primary hepatocellular carcinomas and 12 human normal liver tissues were detected for expression of ephrin type-A receptor 2, E-cadherin, and N-cadherin by immunochemistry. Cinicopathological features of hepatocellular carcinoma and tumor recurrence after operation were studied for the association with these molecular expressions and E-N cadherin switch.

Results

Increased expressions of ephrin type-A receptor 2 and N-cadherin and reduced expression of E-cadherin were significantly detected in hepatocellular carcinoma compared with normal liver tissues. Univariate analysis showed that there were close associations between unfavorable clinicopathological features and expressions of ephrin type-A receptor 2, E-cadherin, N-cadherin, and E-N cadherin switch. Ephrin type-A receptor 2 and E-cadherin expressions were confirmed as independent prognostic factors when corrected with age, gender, AFP, HBsAg, liver cirrhosis, tumor size, nodules, capsule, portal vein invasion, cell differentiation, and TNM stage.

Conclusions

The overexpression of ephrin type-A receptor 2 protein is correlated with the number of tumors, capsular integrity, portal vein cancer thrombus and clinical stages. Epithelial-mesenchymal transition regulated by ephrin type-A receptor 2 is involved in the aggressive clinicopathological features and prognosis, suggesting that the receptor may play an important role in the progression and metastasis of hepatocellular carcinoma.

Immunohistochemical demonstration of EphA2 processing by MT1-MMP in invasive cutaneous squamous cell carcinoma

Erythropoietin-producing hepatocellular receptor-2 (EphA2) overexpression is prevalent in many types of human cancers, and it has been reported that high EphA2 expression is correlated with malignancy. Recent studies revealed that processing of EphA2 by cleaving off the N-terminal portion by membrane-type 1 matrix metalloproteinase (MT1-MMP) promotes invasion via stimulation of Ras in cancer cells in vitro. The objectives of this study were to investigate the presence and role of EphA2 processing in cutaneous squamous cell carcinoma (SCC) tissues. EphA2 (C-terminal and N-terminal) and MT1-MMP expression patterns and levels were analyzed immunohistochemically in SCC (n = 70) and Bowen disease (BD; n = 20). Levels of MT1-MMP and EphA2 expression were evaluated using digital image analysis. Proximity between MT1-MMP and EphA2 in cancer cells and its effect on EphA2 processing were investigated using a combination of in situ proximity ligation assay (PLA) and Western blotting. Immunohistochemical analyses showed that levels of EphA2 N-terminal expression were significantly lower than those of EphA2 C-terminal expression in SCC, whereas levels of EphA2 C- and N-terminal expression were similar in BD. Western blotting showed processed EphA2 fragments in human SCC tissues. Expression levels of MT1-MMP, EphA2, and processed EphA2 fragments were higher in SCC than BD. Proximity between MT1-MMP and EphA2 in SCC was demonstrated by in situ PLA. Our results suggest possible involvement of MT1-MMP processing of EphA2 in invasiveness of cutaneous SCC.

The association between osteopontin and survival in non-small-cell lung cancer patients: a meta-analysis of 13 cohorts

In the last decade, osteopontin (OPN) was identified as one of the important proteins that promote the metastasis of tumor. However, the association between OPN overexpression and clinical outcome of non-small-cell lung cancer (NSCLC) was unclear. The purpose of this study is to investigate the role of OPN in NSCLC patients. A total of 13 studies are included to explore the relationship between the OPN elevation and the overall survival (OS) and disease-free survival (DFS) in NSCLC patients. We searched for related articles in PubMed, Web of Science, Google Scholar, and Cochrane Library databases, which were published before January 31, 2015. Hazard ratio (HR), odds ratio (OR), and 95% confidence interval (CI) in the high OPN expression group compared with the low OPN expression group were calculated and analyzed. Primary results were summarized by using a fixed-effects model or a random-effects model. The stratified analyses in subgroups were also performed. Thirteen cohort studies, which involved 1,630 patients, were included. Subgroup analyses were performed by area and test method of OPN. We found that OPN was significantly associated with poor OS (HR =2.20, 95% CI 1.71–2.83, P<0.001) and DFS (HR =2.11, 95% CI 1.62–2.74, P<0.001) in NSCLC patients. OPN overexpression tended to be associated with the presence of advanced tumor TNM stage (III and IV) (OR =2.57, 95% CI 1.61–4.11, P<0.001). The Egger’s test suggested that there was no publication bias in OS studies (P=0.062) and DFS studies (P=0.740). These data indicate that OPN seems to have a significant predictive potential in estimating survival in NSCLC.

Screening for tumor suppressors: Loss of ephrin receptor A2 cooperates with oncogenic KRas in promoting lung adenocarcinoma

Lung adenocarcinoma, a major form of non-small cell lung cancer, is the leading cause of cancer deaths. The Cancer Genome Atlas analysis of lung adenocarcinoma has identified a large number of previously unknown copy number alterations and mutations, requiring experimental validation before use in therapeutics. Here, we describe an shRNA-mediated high-throughput approach to test a set of genes for their ability to function as tumor suppressors in the background of mutant KRas and WT Tp53. We identified several candidate genes from tumors originated from lentiviral delivery of shRNAs along with Cre recombinase into lungs of Loxp-stop-Loxp-KRas mice. Ephrin receptorA2 (EphA2) is among the top candidate genes and was reconfirmed by two distinct shRNAs. By generating knockdown, inducible knockdown and knockout cell lines for loss of EphA2, we showed that negating its expression activates a transcriptional program for cell proliferation. Loss of EPHA2 releases feedback inhibition of KRAS, resulting in activation of ERK1/2 MAP kinase signaling, leading to enhanced cell proliferation. Intriguingly, loss of EPHA2 induces activation of GLI1 transcription factor and hedgehog signaling that further contributes to cell proliferation. Small molecules targeting MEK1/2 and Smoothened hamper proliferation in EphA2-deficient cells. Additionally, in EphA2 WT cells, activation of EPHA2 by its ligand, EFNA1, affects KRAS-RAF interaction, leading to inhibition of the RAS-RAF-MEK-ERK pathway and cell proliferation. Together, our studies have identified that (i) EphA2 acts as a KRas cooperative tumor suppressor by in vivo screen and (ii) reactivation of the EphA2 signal may serve as a potential therapeutic for KRas-induced human lung cancers.

EphB1 Suppression in Acute Myelogenous Leukemia: Regulating the DNA Damage Control System

Loss of ephrin receptor (EphB1) expression may associate with aggressive cancer phenotypes; however, the mechanism of action remains unclear. To gain detailed insight into EphB1 function in acute myelogenous leukemia (AML), comprehensive analysis of EphB1 transcriptional regulation was conducted. In AML cells, EphB1 transcript was inversely correlated with EphB1 promoter methylation. The presence of EphB1 allowed EfnB1 ligand-mediated p53 DNA binding, leading to restoration of the DNA damage response (DDR) cascade by the activation of ATR, Chk1, p53, p21, p38, CDK1(tyr15), and Bax, and downregulation of HSP27 and Bcl2. Comparatively, reintroduction of EphB1 expression in EphB1-methylated AML cells enhanced the same cascade of ATR, Chk1, p21, and CDK1(tyr15), which consequently enforced programmed cell death. Interestingly, in pediatric AML samples, EphB1 peptide phosphorylation and mRNA expression were actively suppressed as compared with normal bone marrow, and a significant percentage of the primary AML specimens had EphB1 promoter hypermethylation. Finally, EphB1 repression associated with a poor overall survival in pediatric AML. Combined, the contribution of EphB1 to the DDR system reveals a tumor-suppressor function for EphB1 in pediatric AML.

IMPLICATIONS

The tumor-suppressor function of EphB1 is clinically relevant across many malignancies, suggesting that EphB1 is an important regulator of common cancer cell transforming pathways.

Label-free detection of rare cell in human blood using gold nano slit surface plasmon resonance

Label-free detection of rare cells in biological samples is an important and highly demanded task for clinical applications and various fields of research, such as detection of circulating tumor cells for cancer therapy and stem cells studies. Surface Plasmon Resonance (SPR) as a label-free method is a promising technology for detection of rare cells for diagnosis or research applications. Short detection depth of SPR (400 nm) provides a sensitive method with minimum interference of non-targets in the biological samples. In this work, we developed a novel microfluidic chip integrated with gold nanoslit SPR platform for highly efficient immunomagnetic capturing and detection of rare cells in human blood. Our method offers simple yet efficient detection of target cells with high purity. The approach for detection consists of two steps. Target cells are firs captured on functionalized magnetic nanoparticles (MNPs) with specific antibody I. The suspension containing the captured cells (MNPs-cells) is then introduced into a microfluidic chip integrated with a gold nanoslit film. MNPs-cells bind with the second specific antibody immobilized on the surface of the gold nanoslit and are therefore captured on the sensor active area. The cell binding on the gold nanoslit was monitored by the wavelength shift of the SPR spectrum generated by the gold nanoslits.

Prognostic role of EphA2 in various human carcinomas: a meta-analysis of 23 related studies

The prognostic role of EphA2 in human carcinomas remains controversial. We systematically reviewed the evidence of assessment of EphA2 expression in cancers to help clarify this issue. PubMed, Embase and Web of Science databases were searched to identify eligible studies to evaluate the association of EphA2 expression and overall survival (OS) of cancers. Hazard ratios (HRs) were pooled to estimate the effect. EphA2 overexpression was significantly correlated with poor OS of patients with cancer (HR: 1.94, 95% confidence interval [CI]: 1.65-2.28). Subgroup analysis also indicated a significant relation between EphA2 overexpression and OS in gastric cancer (HR: 1.95, 95% CI: 1.48-2.59). However, there was no significant relation between EphA2 overexpression and OS in lung cancer (HR: 1.30, 95% CI: 0.93-1.83). Our analyses demonstrate that EphA2 overexpression was effectively predictive of worse prognosis in various human carcinomas. For certain cancers, EphA2 might be a marker of poor prognosis in patients with cancer, except for lung cancer.

Elevated levels of preoperative circulating CD44⁺ lymphocytes and neutrophils predict poor survival for non-small cell lung cancer patients

BACKGROUND

Certain circulating cells have been shown to predict the clinical outcome of several cancers. The objective of this study was to identify clinical, hematological and immunological predictors of prognosis in non-small cell lung cancer (NSCLC) patients.

METHODS

A retrospective study on a prevalent cohort of 225 NSCLC patients hospitalized at the Zhejiang Province Cancer Hospital (ZPCH) was conducted from August 1, 2006 to April 15, 2008. Circulating lymphocytes were measured by flow cytometry. WBC count and classification in peripheral blood were measured with a Coulter counter. We calculated the proportion of patients surviving after first hospital admission and hazard ratios (HR) using the Cox proportional hazards model.

RESULTS

Elevated levels of preoperative circulating CD44(+) lymphocytes, WBCs and neutrophils indicated low cumulative survival. Clinical stage (HR: 2.292; 95% confidence interval (CI): 1.34-3.91, P=0.002), neutrophils (HR: 1.877; 95% CI: 1.34-2.62, P<0.001) and CD44(+) lymphocytes (HR: 1.018; 95% CI: 1.00-1.03, P=0.002) are independent predictors of survival in NSCLC patients, respectively. Elevated levels of CD44(+) lymphocytes and neutrophils correlated with distant metastasis and prognosis in NSCLC patients with stage III/IV, respectively.

CONCLUSIONS

CD44(+) lymphocytes along with neutrophils could serve as an independent prognostic marker for NSCLC patients.

[Application of target peptide in siRNA delivery for the research of lung cancer therapy]

肺癌被认为是全球发病率最高的一种恶性肿瘤，其对化疗药物不敏感且易产生耐药性，因此增强肺癌药物治疗效果是近年来研究的热点。siRNA是一种小RNA分子，可以沉默与之互补的目标mRNA，是一种基因治疗手段。靶向肽是一类小分子多肽，它可以与siRNA联合使用，利用其与肿瘤表面物质特异性结合发挥靶向作用。联合靶向肽的特异性和siRNA的治疗作用，增加siRNA在靶点位置的聚集，增强沉默效果，可以提高肺癌对药物的敏感性并降低耐药作用，进而增强肺癌治疗效果，为肺癌的靶向治疗提供新的方向和策略。本文将对靶向肽在递送siRNA进行肺癌治疗研究中的应用作一简要综述。

Discoidin domain receptors: a proteomic portrait

The discoidin domain receptors (DDRs) are collagen-binding receptor tyrosine kinases that have been implicated in a number of fundamental biological processes ranging from growth and development to immunoregulation. In this review, we examine how recent proteomic technologies have enriched our understanding of DDR signaling mechanisms. We provide an overview on the use of large-scale proteomic profiling and chemical proteomics to reveal novel insights into DDR therapeutics, signaling networks, and receptor crosstalk. A perspective of how proteomics may be harnessed to answer outstanding fundamental questions including the dynamic regulation of receptor activation kinetics is presented. Collectively, these studies present an emerging molecular portrait of these unique receptors and their functional role in health and disease.

MicroRNA 520d-3p inhibits gastric cancer cell proliferation, migration, and invasion by downregulating EphA2 expression

Aberrant expression of microRNAs (miRNAs) has been shown to play important roles in cancer progression as a result of changes in expression of their target genes. In this study, we investigated the roles of miR-520d-3p on gastric cancer (GC) cell proliferation, migration, and invasion, and confirmed that this miRNA regulates EphA2 expression. The mRNA expression levels of miR-520d-3p and EphA2 in GC tissues and cell lines were evaluated. The clinical and prognostic significance of miR-520d-3p was assessed. The biological function of miR-520d-3p in GC cells was investigated using a methylthiazolyldiphenyl-tetrazolium bromide assay, cell cycle assay, transwell invasion assay, and wound-healing assay. miR-520d-3p expression was down-regulated and inversely correlated with the expression of EphA2 in GC tissues and cell lines. Lower expression of miR-520d-3p was associated with tumor invasion (P = 0.0357), lymph nodes metastasis (P = 0.0272), a higher clinical stage (P = 0.0041), and poorer overall survival (P = 0.0105). Luciferase assays revealed that miR-520d-3p inhibited EphA2 expression by targeting the 3'-untranslated region of EphA2 mRNA. Overexpression of miR-520d-3p dramatically inhibited the proliferation, cell cycle progression, invasion, and migration of GC cells, while down-regulation substantially promoted these properties. Moreover, c-Myc, CyclinD1, and matrix metalloproteinase-9 expression levels were down-regulated in miR-520d-3p mimic-transfected cells and up-regulated in miR-520d-3p inhibitor-transfected cells. Taken together, our data showed that miR-520d-3p appears to contribute to GC progression via the regulation of EphA2 and could serve as a novel prognostic and potential therapeutic marker.

Lack of ephrin receptor A1 is a favorable independent prognostic factor in clear cell renal cell carcinoma

The EPH receptor tyrosine kinases and their cell-bound ligands, the ephrins, have been shown to be associated with cancer development and progression. In this study, mRNA and protein expression of the receptors EPHA1 and EPHA2 as well as of their ligand EFNA1 and their prognostic relevance in clear cell renal cell carcinoma was evaluated. Gene expression was measured in 75 cryo-preserved primary tumors and matched non-malignant renal specimens by quantitative PCR. Protein expression was analyzed by immunohistochemistry on tissue microarrays comprising non-malignant, primary tumors and metastatic renal tissues of 241 patients. Gene and protein expression of all three factors was altered in tumor specimens with EPHA1 and EPHA2 being generally diminished in tumors compared to normal renal tissue, whereas EFNA1 was commonly elevated. A positive EPHA1 and EPHA2 protein staining as well as a low EFNA1 protein level were significantly linked to more aggressive tumor features, but only a positive EPHA1 immunoreactivity was significantly associated with poor survival. In subgroup analyses, EPHA1 and EPHA2 protein levels were significantly higher in metastatic than in primary lesions. Patients with EPHA1/EPHA2-positive tumors or with tumors with positive EPHA1 and low EFNA1 immunoreactivity had the shortest survival rates compared to the respective other combinations. In a multivariate model, EPHA1 was an independent prognostic marker for different survival endpoints. In conclusion, an impaired EPH-ephrin signaling could contribute to the pathogenesis and progression of clear cell renal cell carcinoma.

Ephrin (Eph) receptor A1, A4, A5 and A7 expression in human non-small cell lung carcinoma: associations with clinicopathological parameters, tumor proliferative capacity and patients' survival

Background

Ephrin (Eph) receptors are frequently overexpressed in a wide variety of human malignant tumors, being associated with tumor growth, invasion, metastasis and angiogenesis. The present study aimed to evaluate the clinical significance of EphA1, A4, A5 and A7 protein expression in non-small cell lung carcinoma (NSCLC).

Methods

EphA1, A4, A5 and A7 protein expression was assessed immunohistochemically in tissue microarrays of 88 surgically resected NSCLC and was analyzed in relation with clinicopathological characteristics and patients’ survival.

Results

Elevated EphA4 expression was significantly associated with low histopathological stage and presence of inflammation (p = 0.047 and p = 0.026, respectively). Elevated EphA7 expression was significantly associated with older patients’ age, presence of fibrosis and smaller tumor size (p = 0.036, p = 0.029 and p = 0.018, respectively). EphA1, A5 and A7 expression were positively associated with tumor proliferative capacity (p = 0.047, p = 0.002 and p = 0.046, respectively). Elevated EphA4, A5 and A7 expression were identified as predictors of favourable patients’ survival at both univariate (Log-rank test, 0 = 0.019, p = 0.006 and p = 0.012, respectively) and multivariate levels (Cox-regression analysis, p = 0.029, p = 0.068 and p = 0.044, respectively).

Conclusions

The present study supported evidence that Ephs may be involved in lung cancer progression, reinforcing their utility as clinical biomarkers for patients’ management and prognosis, as also as potential targets for future therapeutic interventions.

Osteopontin is a prognostic biomarker in non-small cell lung cancer

BACKGROUND

In a previously published report we characterized the expression of the metastasis-associated proteins S100A4, osteopontin (OPN) and ephrin-A1 in a prospectively collected panel of non-small cell lung cancer (NSCLC) tumors. The aim of the present follow-up study was to investigate the prognostic impact of these potential biomarkers in the same patient cohort. In addition, circulating serum levels of OPN were measured and single nucleotide polymorphisms (SNP) in the -443 position of the OPN promoter were analyzed.

METHODS

Associations between immunohistochemical expression of S100A4, OPN and ephrin-A1 and relapse free and overall survival were examined using univariate and multivariate analyses. Serum OPN was measured by ELISA, polymorphisms in the -443 position of the tumor OPN promoter were analyzed by PCR, and associations between OPN levels and promoter polymorphisms and clinicopathological parameters and patient outcome were investigated.

RESULTS

High expression of OPN in NSCLC tumors was associated with poor patient outcome, and OPN was a strong, independent prognostic factor for both relapse free and overall survival. Serum OPN levels increased according to tumor pT classification and tumor size, and patients with OPN-expressing tumors had higher serum levels than patients with OPN-negative tumors. S100A4 was a negative prognostic factor in several subgroups of adenocarcinoma patients, but not in the overall patient cohort. There was no association between ephrin-A1 expression and patient outcome.

CONCLUSIONS

OPN is a promising prognostic biomarker in NSCLC, and should be further explored in the selection of patients for adjuvant treatment following surgical resection.

Prognostic significance of combinations of RNA-dependent protein kinase and EphA2 biomarkers for NSCLC

INTRODUCTION

RNA-dependent protein kinase (PKR) is an independent prognostic variable in patients with non-small-cell lung cancer (NSCLC). In the current study, we investigated the correlation between PKR and 25 other biomarkers for NSCLC, identified the markers that could further improve the prognostic significance of PKR and elucidated the mechanisms of interaction between these markers and PKR.

METHODS

Tissue microarray samples obtained from 218 patients with lung cancer were stained with an anti-PKR antibody and antibodies against 25 biomarkers. Immunohistochemical expression was scored and used for Kaplan-Meier survival analysis. The interaction between PKR and EphA2 in NSCLC cell lines was examined.

RESULTS

We found that PKR was associated with EphA2 and that the prognostic information regarding NSCLC provided by the combination of PKR and EphA2 (P/E) was significantly more accurate than that provided by either marker alone. The 5-year overall survival rate in patients with PKR/EphA2 (20%) was significantly lower than that of patients with PKR/EphA2 (74%), patients with PKR/EphA2 (55%), and patients with PKR/EphA2 (55%) (p < 0.0001). We also found that the PKR:EphA2 (P/E) ratio was significantly associated with prognosis (p < 0.0001). Univariate and multivariate Cox analyses revealed that this P/E combination or ratio was an independent predictor of overall survival. In addition, induction of PKR expression reduced EphA2 protein expression levels in NSCLC cell lines.

CONCLUSIONS

PKR/EphA2 is a significant predictor of prognosis for NSCLC. PKR/EphA2 may be a promising approach to improving screening efficiency and predicting prognosis in patients with NSCLC.

The EphB4 receptor tyrosine kinase promotes lung cancer growth: a potential novel therapeutic target

Despite progress in locoregional and systemic therapies, patient survival from lung cancer remains a challenge. Receptor tyrosine kinases are frequently implicated in lung cancer pathogenesis, and some tyrosine kinase inhibition strategies have been effective clinically. The EphB4 receptor tyrosine kinase has recently emerged as a potential target in several other cancers. We sought to systematically study the role of EphB4 in lung cancer. Here, we demonstrate that EphB4 is overexpressed 3-fold in lung tumors compared to paired normal tissues and frequently exhibits gene copy number increases in lung cancer. We also show that overexpression of EphB4 promotes cellular proliferation, colony formation, and motility, while EphB4 inhibition reduces cellular viability in vitro, halts the growth of established tumors in mouse xenograft models when used as a single-target strategy, and causes near-complete regression of established tumors when used in combination with paclitaxel. Taken together, these data suggest an important role for EphB4 as a potential novel therapeutic target in lung cancer. Clinical trials investigating the efficacy of anti-EphB4 therapies as well as combination therapy involving EphB4 inhibition may be warranted.

Expression of S100A4, ephrin-A1 and osteopontin in non-small cell lung cancer

Background

The metastasis-promoting protein S100A4 induces expression of ephrin-A1 and osteopontin in osteosarcoma cell lines. The aim of this study was to investigate S100A4-mediated stimulation of ephrin-A1 and osteopontin in non-small cell lung cancer (NSCLC) cell lines, and to characterize the expression of these biomarkers in primary tumor tissue from NSCLC patients.

Methods

Four NSCLC cell lines were treated with extracellular S100A4, and ephrin-A1 and osteopontin expression was analyzed by real time RT-PCR and Western blotting. Immunohistochemical staining for S100A4, ephrin-A1 and osteopontin was performed on tissue microarrays containing primary tumor samples from a cohort of 217 prospectively recruited NSCLC patients, and associations with clinicopathological parameters were investigated.

Results

S100A4 induced ephrin-A1 mRNA and protein expression in adenocarcinoma, but not in squamous carcinoma cell lines, whereas the level of osteopontin was unaffected by S100A4 treatment. In primary tumors, moderate or strong immunoreactivity was observed in 57% of cases for cytoplasmic S100A4, 46% for nuclear S100A4, 86% for ephrin-A1 and 77% for osteopontin. Interestingly, S100A4 expression was associated with ephrin-A1 also in vivo, but there was no association between S100A4 and osteopontin. Expression levels of S100A4 and ephrin-A1 were significantly higher in adenocarcinomas compared to other histological subtypes, and S100A4-positive tumors were smaller and more differentiated than tumors without expression.

Conclusions

Our findings suggest that S100A4, ephrin-A1 and osteopontin are involved in the biology of NSCLC, and further investigation of their potential use as biomarkers in NSCLC is warranted.