Cell adhesion molecules: role and clinical significance in cancer

Epithelial-Mesenchymal Transition (EMT) and Prostate Cancer

Typically the normal epithelial cells are a single layer, held tightly by adherent proteins that prevent the mobilization of the cells from the monolayer sheet. During prostate cancer progression, the epithelial cells can undergo epithelial-mesenchymal transition or EMT, characterized by morphological changes in their phenotype from cuboidal to spindle-shaped. This is associated with biochemical changes in which epithelial cell markers such as E-cadherin and occludins are down-regulated, which leads to loss of cell-cell adhesion, while mesenchymal markers such as vimentin and N-cadherin are up-regulated, thereby allowing the cells to migrate or metastasize to different organs. The EMT transition can be regulated directly and indirectly by multiple molecular mechanisms including growth factors and cytokines such as transforming growth factor-beta (TGF-β), epidermal growth factor (EGF) and insulin-like growth factor (IGF), and signaling pathways such as mitogen-activated protein kinase (MAPK) and Phosphatidylinositol 3-Kinase (PI3K). This signaling subsequently induces expression of various transcription factors like Snail, Twist, Zeb1/2, that are also known as master regulators of EMT. Various markers associated with EMT have been reported in prostate cancer patient tissue as well as a possible association with health disparities. There has been consideration to therapeutically target EMT in prostate cancer patients by targeting the EMT signaling pathways.

A Functional Analysis on the Interspecies Interaction between Mouse LFA-1 and Human Intercellular Adhesion Molecule-1 at the Cell Level

The interaction between intercellular adhesion molecules (ICAM) and the integrin leukocyte function-associated antigen-1 (LFA-1) is crucial for the regulation of several physiological and pathophysiological processes like cell-mediated elimination of tumor or virus infected cells, cancer metastasis, or inflammatory and autoimmune processes. Using purified proteins it was reported a species restriction for the interaction of ICAM-1 and LFA-1, being mouse ICAM-1 able to interact with human LFA-1 but not human ICAM-1 with mouse LFA-1. However, in vivo results employing tumor cells transfected with human ICAM-1 suggest that functionally mouse LFA-1 can recognize human ICAM-1. In order to clarify the interspecies cross-reactivity of the ICAM-1/LFA-1 interaction, we have performed functional studies analyzing the ability of human soluble ICAM-1 and human/mouse LFA-1 derived peptides to inhibit cell aggregation and adhesion as well as cell-mediated cytotoxicity in both mouse and human systems. In parallel, the affinity of the interaction between mouse LFA-1-derived peptides and human ICAM-1 was determined by calorimetry assays. According to the results obtained, it seems that human ICAM-1 is able to interact with mouse LFA-1 on intact cells, which should be taking into account when using humanized mice and xenograft models for the study of immune-related processes.

The potential role of leptin in tumor invasion and metastasis

The adipocyte-released hormone-like cytokine/adipokine leptin behaves differently in obesity compared to its functions in the normal healthy state. In obese individuals, elevated leptin levels act as a pro-inflammatory adipokine and are associated with certain types of cancers. Further, a growing body of evidence suggests that higher circulating leptin concentrations and/or elevated expression of leptin receptors (Ob-R) in tumors may be poor prognostic factors. Although the underlying pathological mechanisms of leptin's association with poor prognosis are not clear, leptin can impact the tumor microenvironment in several ways. For example, leptin is associated with a number of biological components that could lead to tumor cell invasion and distant metastasis. This includes interactions with carcinoma-associated fibroblasts, tumor promoting effects of infiltrating macrophages, activation of matrix metalloproteinases, transforming growth factor-β signaling, etc. Recent studies also have shown that leptin plays a role in the epithelial-mesenchymal transition, an important phenomenon for cancer cell migration and/or metastasis. Furthermore, leptin's potentiating effects on insulin-like growth factor-I, epidermal growth factor receptor and HER2/neu have been reported. Regarding unfavorable prognosis, leptin has been shown to influence both adenocarcinomas and squamous cell carcinomas. Features of poor prognosis such as tumor invasion, lymph node involvement and distant metastasis have been recorded in several cancer types with higher levels of leptin and/or Ob-R. This review will describe the current scenario in a precise manner. In general, obesity indicates poor prognosis in cancer patients.

Exenatide modulates tumor-endothelial cell interactions in human ovarian cancer cells

Diabetes and cancer are prevalent diseases whose incidence is increasing globally. Diabetic women have a moderate risk increase in ovarian cancer, suggested to be due to an interaction between these two disorders. Furthermore, patients manifesting both diseases have associated worse prognosis, reduced survival and shorter relapse-free survival. According to current recommendations, incretin drugs such as Exenatide, a synthetic analog of Exendin-4, and Liraglutide are used as therapy for the type 2 diabetes (T2D). We studied the effects of GLP-1 and Exendin-4 on migration, apoptosis and metalloproteinase production in two human ovarian cancer cells (SKOV-3 and CAOV-3). Exendin-4 inhibited migration and promoted apoptosis through caspase 3/7 activation. Exendin-4 also modulated the expression of key metalloproteinases (MMP-2 and MMP-9) and their inhibitors (TIMP-1 and TIMP-2). Vascular endothelial cells, which contribute to the formation and progression of metastasis, were also analyzed. TNF-α-stimulated endothelial cells from iliac artery after Exendin-4 treatment showed reduced production of adhesion molecules (ICAM-1 and VCAM-1). Additionally, incretin treatment inhibited activation of apoptosis in TNF-α-stimulated endothelial cells. In the same experiment, MMPs (MMP-1 and MMP-9), which are relevant for tumor development, were also reduced. Our study demonstrated that incretin drugs may reduce cancer cell proliferation and dissemination potential, hence limiting the risk of metastasis in epithelial ovarian cancer.

Insufficient Radiofrequency Ablation Treated Hepatocellular Carcinoma Cells Promote Metastasis by Up-Regulation ITGB3

Radiofrequency ablation (RFA) is one of the standards of care for early stage hepatocellular carcinoma (HCC). However, rapid progression of residual tumor after RFA has been confirmed. The aim of this study was to investigate the underlying mechanism of this phenomenon. Human HCC cell lines HCCLM3 and HepG2 were employed to establish insufficient RFA models in vivo and in vitro, respectively. The effects of insufficient RFA on metastatic potential of residual tumors were evaluated. The molecular changes after insufficient RFA were evaluated by PCR array, western blot, immunofluorescence, and immunohistochemistry. Results showed that insufficient RFA significantly promoted lung and intrahepatic residual tumor cells in vivo, and heat intervention promoted migration and invasion of hepatoma cells in vitro. PCR array revealed that the expression of integrin β3 (ITGB3) and MMP2 were up-regulated in the residual tumors of HCCLM3 xenograft model. The up-regulation of ITGB3 was confirmed by qRT-PCR, Western blot and immunohistochemistry. Knockdown ITGB3 expression in HCCLM3 cells by shRNA significantly lowered the pro-metastatic effects of insufficient RFA. Mechanism studies indicated that ITGB3 mediated the expression of MMP2 by activing FAK/PI3K/AKT signaling pathway. The up-regulation of ITGB3 contributed to enhanced metastatic potential of residual cancer in HCCLM3 model after insufficient RFA. Targeting ITGB3 expression may further improve the clinical effects of RFA.

Ninjurin 1 has two opposing functions in tumorigenesis in a p53-dependent manner

WT p53 is critical for tumor suppression, whereas mutant p53 promotes tumor progression. Nerve injury-induced protein 1 (Ninj1) is a target of p53 and forms a feedback loop with p53 by repressing p53 mRNA translation. Here, we show that loss of Ninj1 increased mutant p53 expression and, subsequently, enhanced cell growth and migration in cells carrying a mutant p53. In contrast, loss of Ninj1 inhibited cell growth and migration in cells carrying a WT p53. To explore the biological significance of Ninj1, we generated a cohort of Ninj1-deficient mice and found that Ninj1^+/- mice were prone to systemic inflammation and insulitis, but not to spontaneous tumors. We also found that loss of Ninj1 altered the tumor susceptibility in both mutant p53 and p53-null background. Specifically, in a mutant p53(R270H) background, Ninj1 deficiency shortened the lifespan, altered the tumor spectrum, and increased tumor burden, likely via enhanced expression of mutant p53. In a p53-null background, Ninj1 deficiency significantly increased the incidence of T-lymphoblastic lymphoma. Taken together, our data suggest that depending on p53 genetic status, Ninj1 has two opposing functions in tumorigenesis and that the Ninj1-p53 loop may be targeted to manage inflammatory diseases and cancer.

New perspectives of cobalt tris(bipyridine) system: anti-cancer effect and its collateral sensitivity towards multidrug-resistant (MDR) cancers

Platinating compounds including cisplatin, carboplatin, and oxaliplatin are common chemotherapeutic agents, however, patients developed resistance to these clinical agents after initial therapeutic treatments. Therefore, different approaches have been applied to identify novel therapeutic agents, molecular mechanisms, and targets for overcoming drug resistance. In this study, we have identified a panel of cobalt complexes that were able to specifically induce collateral sensitivity in taxol-resistant and p53-deficient cancer cells. Consistently, our reported anti-cancer functions of cobalt complexes 1-6 towards multidrug-resistant cancers have suggested the protective and non-toxic properties of cobalt metal-ions based compounds in anti-cancer therapies. As demonstrated in xenograft mouse model, our results also confirmed the identified cobalt complex 2 was able to suppress tumor growth in vivo. The anti-cancer effect of the cobalt complex 2 was further demonstrated to be exerted via the induction of autophagy, cell cycle arrest, and inhibition of cell invasion and P-glycoprotein (P-gp) activity. These data have provided alternative metal ion compounds for targeting drug resistance cancers in chemotherapies.

CD300LG improves the cytotoxic activity of CIK

To investigate the effect of CD300LG-γ induction on the cytotoxic activity of CIK. Eukaryotic expression plasmid hCD300LG-γ/pEGFP-C3, which can express human CD300LG-γ, was constructed and transfected into CHO cells by lipofectamine. The expression of CD300LG-γ was confirmed by immunofluorescence, RT-PCR, and Western Blot. To produce CIK cells, human peripheral blood mononuclear cells (PBMC) were isolated and induced, respectively, by cell lysates extracted from hCD300LG-γ/CHO cells, pEGFP-C3/CHO cells, and CHO cells, concurrently with the standard CIK inductive agent. The cytotoxic activity of these CIK cells against hCD300LG-γ/CHO cells, pEGFP-C3/CHO cells, CHO cells, and K562 cells was tested. The results showed that eukaryotic expression of plasmid hCD300LG-γ/pEGFP-C3 was constructed and transfected into CHO cells successfully. After being induced by cell lysates, the cytotoxicity of hCD300LG-γ/CHO-CIK was improved compared with the other CIK cells. In particular, the activity of killing pEGFP-C3/CHO and CHO cells was improved significantly. Meanwhile, the activity of hCD300LG-γ/CHO-CIK killing K562 was improved significantly compared with the other CIK cells. The results indicated that hCD300LG-γ induction can significantly improve the killing activity of CIK cells.

Label-free profiling of cell dynamics: A sequence of impedance-based assays to estimate tumor cell invasiveness in vitro

Dynamic properties of cancer cells, most notably their ability to migrate, have been correlated successfully with their invasive nature in vivo. To establish a stronger experimental basis for such a correlation we subjected five different cancer cell lines of well-defined metastatic potential to a sequence of three independent assays reporting on three different aspects of cell dynamics, namely (1) the kinetics of cell spreading, (2) cell shape fluctuations, and (3) cell migration. The sequentially applied assays correspond to different measuring modes of the well-established ECIS technique that is based on non-invasive and label-free impedance readings of planar gold-film electrodes that serve as the growth substrate for the cells under study. Every individual assay returned a characteristic parameter describing the behavior of the cell lines in that particular assay quantitatively. The parameters of all three assays were ranked to establish individual profiles of cell dynamics for every cell line that correlate favorably with the cells' invasive properties. The sequence of impedance-based assays described here requires only small cell populations (< 10.000 cells), it is highly automated and easily adapted to 96-well formats. It provides an in-depth dynamic profile of adherent cells that might be useful in other areas besides cancer research as well.

Identifying CpG sites with different differential methylation frequencies in colorectal cancer tissues based on individualized differential methylation analysis

A big challenge to clinical diagnosis and therapy of colorectal cancer (CRC) is its extreme heterogeneity, and thus it would be of special importance if we could find common biomarkers besides subtype-specific biomarkers for CRC. Here, with DNA methylation data produced by different laboratories, we firstly revealed that the relative methylation-level orderings (RMOs) of CpG sites within colorectal normal tissues are highly stable but widely disrupted in the CRC tissues. This finding provides the basis for using the RankComp algorithm to identify differentially methylated (DM) CpG sites in every individual CRC sample through comparing the RMOs within the individual sample with the stable RMOs predetermined in normal tissues. For 75 CRC samples, RankComp detected averagely 4,062 DM CpG sites per sample and reached an average precision of 91.34% in terms that the hypermethylation or hypomethylation states of the DM CpG sites detected for each cancer sample were consistent with the observed differences between this cancer sample and its paired adjacent normal sample. Finally, we applied RankComp to identify DM CpG sites for each of the 268 CRC samples from The Cancer Genome Atlas and found 26 and 143 genes whose promoter regions included CpG sites that were hypermethylated and hypomethylated, respectively, in more than 95% of the 268 CRC samples. Individualized pathway analysis identified six pathways that were significantly enriched with DM genes in more than 90% of the CRC tissues. These universal DNA methylation biomarkers could be important diagnostic makers and therapy targets for CRC.

Targeting integrins with RGD-conjugated gold nanoparticles in radiotherapy decreases the invasive activity of breast cancer cells

Gold nanoparticles (AuNPs) have recently attracted attention as clinical agents for enhancing the effect of radiotherapy in various cancers. Although radiotherapy is a standard treatment for cancers, invasive recurrence and metastasis are significant clinical problems. Several studies have suggested that radiation promotes the invasion of cancer cells by activating molecular mechanisms involving integrin and fibronectin (FN). In this study, polyethylene-glycolylated AuNPs (P-AuNPs) were conjugated with Arg–Gly–Asp (RGD) peptides (RGD/P-AuNPs) to target cancer cells expressing RGD-binding integrins such as α5- and αv-integrins. RGD/P-AuNPs were internalized more efficiently and colocalized with integrins in the late endosomes and lysosomes of MDA-MB-231 cells. A combination of RGD/P-AuNPs and radiation reduced cancer cell viability and increased DNA damage compared to radiation alone in MDA-MB-231 cells. Moreover, the invasive activity of breast cancer cell lines after radiation treatment was significantly inhibited in the presence of RGD/P-AuNPs. Microarray analyses revealed that the expression of FN in irradiated cells was suppressed by combined use of RGD/P-AuNPs. Reduction of FN and downstream signaling may be involved in suppressing radiation-induced invasive activity by RGD/P-AuNPs. Our study suggests that RGD/P-AuNPs can target integrin-overexpressing cancer cells to improve radiation therapy by suppressing invasive activity in addition to sensitization. Thus, these findings provide a possible clinical strategy for using AuNPs to treat invasive breast cancer following radiotherapy.

An epigenetic signature of adhesion molecules predicts poor prognosis of ovarian cancer patients

DNA methylation is a promising biomarker for cancer. The epigenetic effects of cell adhesion molecules may affect the therapeutic outcome and the present study examined their effects on survival in ovarian cancer. We integrated methylomics and genomics datasets in The Cancer Genome Atlas (n = 391) and identified 106 highly methylated adhesion-related genes in ovarian cancer tissues. Univariate analysis revealed the methylation status of eight genes related to progression-free survival. In multivariate Cox regression analysis, four highly methylated genes (CD97, CTNNA1, DLC1, HAPLN2) and three genes (LAMA4, LPP, MFAP4) with low methylation were significantly associated with poor progression-free survival. Low methylation of VTN was an independent poor prognostic factor for overall survival after adjustment for age and stage. Patients who carried any two of CTNNA1, DLC1 or MFAP4 were significantly associated with poor progression-free survival (hazard ratio: 1.59; 95% confidence interval: 1.23, 2.05). This prognostic methylation signature was validated in a methylomics dataset generated in our lab (n = 37, hazard ratio: 16.64; 95% confidence interval: 2.68, 103.14) and in another from the Australian Ovarian Cancer Study (n = 91, hazard ratio: 2.43; 95% confidence interval: 1.11, 5.36). Epigenetics of cell adhesion molecules is related to ovarian cancer prognosis. A more comprehensive methylomics of cell adhesion molecules is needed and may advance personalized treatment with adhesion molecule-related drugs.

miR-10a suppresses colorectal cancer metastasis by modulating the epithelial-to-mesenchymal transition and anoikis

MicroRNAs (miRNAs) have a critical role in tumorigenesis and metastasis, which are major obstacles of cancer therapy. However, the role of miRNAs in colorectal cancer (CRC) metastasis remains poorly understood. Here, we found that miRNA-10a (miR-10a) was upregulated in primary CRC tissues and cell line (SW480) derived from primary CRC compared with metastatic cancer tissues in lymph node and cell line (SW620). The differential expression of miR-10a was inversely correlated with distant metastasis and invasion depth. miR-10a promoted migration and invasion in vitro but inhibited metastasis in vivo by regulating the epithelial-to-mesenchymal transition and anoikis. Furthermore, matrix metalloproteinase 14 (MMP14) and actin gamma 1 (ACTG1) were validated as target genes of miR-10a in CRC cells. Ectopic expression of MMP14 and ACTG1 counteracted the decreased cell adhesion and anoikis resistance activities induced by miR-10a. These findings not only describe the mechanism by which miR-10a suppresses CRC metastasis but also suggest the potential prognostic and therapeutic value of miR-10a in CRC patients.

The role of Slit-Robo signaling in the regulation of tissue barriers

The role of Slit/Robo signaling has extended from initial axon repulsion in the developing nervous system to organ morphogenesis, cancer development and angiogenesis. Slit/Robo signaling regulates similar pathways within these processes. Slit/Robo ensures the homeostasis of the dynamic interaction between cell-cell and cell-matrix interactions. The dysregulation of Slit/Robo signaling damages the tissue barrier, resulting in developmental abnormalities or disease. Here, we summarize how Slit/Robo controls kidney morphogenesis and describe the dual roles of Slit/Robo signaling in the regulation of tumorigenesis and angiogenesis.

Orphan G protein-coupled receptor GPRC5A modulates integrin β1-mediated epithelial cell adhesion

G-Protein Coupled Receptor (GPCR), Class C, Group 5, Member A (GPRC5A) has been implicated in several malignancies. The underlying mechanisms, however, remain poorly understood. Using a panel of human cell lines, we demonstrate that CRISPR/Cas9-mediated knockout and RNAi-mediated depletion of GPRC5A impairs cell adhesion to integrin substrates: collagens I and IV, fibronectin, as well as to extracellular matrix proteins derived from the Engelbreth-Holm-Swarm (EHS) mouse sarcoma (Matrigel). Consistent with the phenotype, knock-out of GPRC5A correlated with a reduced integrin β1 (ITGB1) protein expression, impaired phosphorylation of the focal adhesion kinase (FAK), and lower activity of small GTPases RhoA and Rac1. Furthermore, we provide the first evidence for a direct interaction between GPRC5A and a receptor tyrosine kinase EphA2, an upstream regulator of FAK, although its contribution to the observed adhesion phenotype is unclear. Our findings reveal an unprecedented role for GPRC5A in regulation of the ITGB1-mediated cell adhesion and it's downstream signaling, thus indicating a potential novel role for GPRC5A in human epithelial cancers.

Dehydropeptidase 1 promotes metastasis through regulation of E-cadherin expression in colon cancer

Dehydropeptidase 1 (DPEP1) is a zinc-dependent metalloproteinase that is expressed aberrantly in several cancers. The role of DPEP1 in cancer remain controversial. In this study, we demonstrate that DPEP1 functions as a positive regulator for colon cancer cell metastasis. The expression of DPEP1 mRNA and proteins were upregulated in colon cancer tissues compared to normal mucosa. Gain-of-function and loss-of-function approaches were used to examine the malignant phenotype of DPEP1-expressing or DPEP1-depleted cells. DPEP1 expression caused a significant increase in colon cancer cell adhesion and invasion in vitro, and metastasis in vivo. In contrast, DPEP1 depletion induced opposite effects. Furthermore, cilastatin, a DPEP1 inhibitor, suppressed the invasion and metastasis of DPEP1-expressing cells. DPEP1 inhibited the leukotriene D4 signaling pathway and increased the expression of E-cadherin. We also show that DPEP1 mediates TGF-β-induced EMT. TGF-β transcriptionally repressed DPEP1 expression. TGF-β treatment decreased E-cadherin expression and promoted cell invasion in DPEP1-expressing colon cancer cell lines, whereas it did not affect these parameters in DPEP1-depleted cell lines. These results suggest that DPEP1 promotes cancer metastasis by regulating E-cadherin plasticity and that it might be a potential therapeutic target for preventing the progression of colon cancer.

The role of the endothelin axis in promoting epithelial to mesenchymal transition and lymph node metastasis in prostate adenocarcinoma

Introduction:

Aberrant activation of endothelin (ET) axis has been identified as a key player in tumor growth and metastasis in several tumor types. However, little is known about the possible interaction of the ET with epithelial to mesenchymal transition (EMT), a process that transforms tumor cells in a motile, resistant to apoptosis phenotype prone to invasion and metastasis. The aim of this study was to investigate the activation of the ET axis in prostate adenocarcinoma and examine possible associations with EMT markers, lymph node (LN) metastasis, and other clinicopathological parameters.

Materials and Methods:

We immunohistochemically evaluated the expression of ET-1 and its receptors A and B (ET-A, ET-B) in 64 N0 and 23 N1 prostate adenocarcinoma cases. EMT markers E-cadherin, N-cadherin, and β-catenin and the transcriptional factor SNAIL were evaluated. We examined possible correlations of ET pathway members with EMT markers, LN status, Gleason grade, and T stage.

Results:

Our results revealed increased expression of ET-1 and ET-A (but not ET-B) in prostate carcinoma; both ET-1 and ET-A were associated with lymph metastasis and T stage but not with Gleason grade. We observed E-cadherin and β-catenin decrease/relocalization and increased N-cadherin expression. SNAIL also showed increased expression in tumor tissue and was associated with LN metastasis (Mann–Whitney test, P = 0.0032). Expression of ET-1 and ET-A correlated well with SNAIL expression (Spearman r, P = 0.0002 and P = 0.0176, respectively).

Conclusions:

These findings indicate that activation of the ET pathway may induce EMT through SNAIL activation and correlates with increased metastatic potential.

Different functions of AKT1 and AKT2 in molecular pathways, cell migration and metabolism in colon cancer cells

AKT is a central protein in many cellular pathways such as cell survival, proliferation, glucose uptake, metabolism, angiogenesis, as well as radiation and drug response. The three isoforms of AKT (AKT1, AKT2 and AKT3) are proposed to have different physiological functions, properties and expression patterns in a cell type-dependent manner. As of yet, not much is known about the influence of the different AKT isoforms in the genome and their effects in the metabolism of colorectal cancer cells. In the present study, DLD-1 isogenic AKT1, AKT2 and AKT1/2 knockout colon cancer cell lines were used as a model system in conjunction with the parental cell line in order to further elucidate the differences between the AKT isoforms and how they are involved in various cellular pathways. This was done using genome wide expression analyses, metabolic profiling and cell migration assays. In conclusion, downregulation of genes in the cell adhesion, extracellular matrix and Notch-pathways and upregulation of apoptosis and metastasis inhibitory genes in the p53-pathway, confirm that the knockout of both AKT1 and AKT2 will attenuate metastasis and tumor cell growth. This was verified with a reduction in migration rate in the AKT1 KO and AKT2 KO and most explicitly in the AKT1/2 KO. Furthermore, the knockout of AKT1, AKT2 or both, resulted in a reduction in lactate and alanine, suggesting that the metabolism of carbohydrates and glutathione was impaired. This was further verified in gene expression analyses, showing downregulation of genes involved in glucose metabolism. Additionally, both AKT1 KO and AKT2 KO demonstrated an impaired fatty acid metabolism. However, genes were upregulated in the Wnt and cell proliferation pathways, which could oppose this effect. AKT inhibition should therefore be combined with other effectors to attain the best effect.

HepaCAM associates with connexin 43 and enhances its localization in cellular junctions

HepaCAM (GlialCAM) is frequently deleted in carcinomas, and reintroduction of hepaCAM into transformed cell lines reduces cellular growth and induces senescence. Mutations in HEPACAM give rise to the neurodegenerative disease megalencephalic leukoencephalopathy with subcortical cysts (MLC) since mutated hepaCAM prevents shuttling of MLC1 protein to astrocytic junctions in the plasma membrane. Here we identify that hepaCAM associates with connexin 43, a main component of gap junctions, and enhances connexin 43 localization to the plasma membrane at cellular junctions. HepaCAM also increases the levels of connexin 43, not by enhancing its transcription but by stabilizing connexin 43 protein. In the absence of hepaCAM, connexin 43 undergoes a faster degradation via the lysosomal pathway while proteasomal degradation seems not to be involved. Mutations in hepaCAM that cause MLC, or neutralization of hepaCAM by antibodies disrupt its association with connexin 43 at cellular junctions. By discovering the requirement of hepaCAM for localizing connexin 43, a well-established tumor suppressor, to cellular junctions and stabilizing it there, this study suggests a mechanism by which deletion of hepaCAM may support tumor progression.

Novel Biomarker Candidates for Colorectal Cancer Metastasis: A Meta-analysis of In Vitro Studies

Colorectal cancer (CRC) is one of the most common and lethal cancers. Although numerous studies have evaluated potential biomarkers for early diagnosis, current biomarkers have failed to reach an acceptable level of accuracy for distant metastasis. In this paper, we performed a gene set meta-analysis of in vitro microarray studies and combined the results from this study with previously published proteomic data to validate and suggest prognostic candidates for CRC metastasis. Two microarray data sets included found 21 significant genes. Of these significant genes, ALDOA, IL8 (CXCL8), and PARP4 had strong potential as prognostic candidates. LAMB2, MCM7, CXCL23A, SERPINA3, ABCA3, ALDH3A2, and POLR2I also have potential. Other candidates were more controversial, possibly because of the biologic heterogeneity of tumor cells, which is a major obstacle to predicting metastasis. In conclusion, we demonstrated a meta-analysis approach and successfully suggested ten biomarker candidates for future investigation.

Adhering towards tumorigenicity: altered adhesion mechanisms in glioblastoma cancer stem cells

Glioblastoma (GBM) is the most aggressive malignant primary brain tumor in adults with a high recurrence and mortality rate. GBM tumors contain a high degree of cellular heterogeneity, with cells exhibiting stem-like properties (cancer stem cells; CSCs) that are highly efficient at tumor initiation and are resistant to conventional therapies. CSCs interact with their tumor microenvironment by a large group of diverse cell adhesion molecules (CAMs) that participate in intercellular, intracellular and cell-extracellular matrix interactions. Despite the initial description of CAMs as tumor suppressors, recent work has highlighted specific CAMs that are essential for CSC maintenance and tumor progression. This review will highlight recent findings that provide support for a context-specific role of CAMs in CSC function and GBM progression.

Overexpression of p42.3 promotes cell proliferation, migration, and invasion in human gastric cancer cells

As a newly discovered tumor-specific gene, p42.3 is overexpressed in most of human gastric cancers (GC). However, the role of p42.3 in GC progression remains unclear. To assess the role of p42.3 in gastric cancers, immunohistochemistry and western blot were performed to detect the p42.3 expression in human GC tissues and cells. We also investigated the role of p42.3 in GC cell proliferation, migration, and invasion. Our results showed that the p42.3 expression was increased dramatically in human GC tissue and cells. In addition, we found that overexpression of p42.3 promotes GC cell proliferation, migration, and invasion abilities. Furthermore, p42.3 expression suppressed the E-cadherin protein level and promoted the β-catenin and p-ERK protein level. Taken together, overexpressed p42.3 is correlated with gastric cancer cell proliferation, migration, and invasion, suggesting its use as a biological marker in gastric cancer.

Cytokines and cell adhesion molecules exhibit distinct profiles in health, ovarian cancer, and breast cancer

Objective

We examined a panel of cytokines and cell adhesion molecules in an attempt to identify cancer specific profiles.

Design and methods

Cytokines and cell adhesion arrays (Randox Ltd.) were measured in samples from women with a histological diagnosis of ovarian cancer (n=42) or breast cancer (n=60) or cancer free (n=32). Random forest analysis was used for classification.

Results

Ovarian cancer subjects were classified with a sensitivity of 85.7% (95% CI 50–100) and a specificity of 84.2% (95% CI 69.4–93.4). Breast cancer subjects were classified with a sensitivity of 70.8% (95% CI 47.1–86.4) and a specificity of 96.4% (95% CI 82.1–100).

Discussion

Cytokine and cell adhesion molecule profiles provide additional information that may be useful for cancer characterization of female cancers.

Immunohistochemical Study EMT-Related Proteins in HPV-, and EBV-Negative Patients with Sinonasal Tumours

Epithelial to mesenchymal transition (EMT) is a biological process in which the epithelial cells, transform to mesenchymal cells via multiple biochemical modifications. Immunohistochemical method was used to examine the expression of EMT-related proteins: Slug, E-cadherin and fibronectin, in 41 cases of sinonasal inverted papilloma (SIP), 33 cases of sinonasal squamous cell carcinoma (SNC), and 22 cases of normal mucosa as a control. In all cases negative viral status was previously confirmed using both in situ hybridization and immunohistochemical method. The immunoexpression of Slug and fibronectin were significantly increased in the SNC group as compared to SIPs and control cases. The immunoexpresssion of Slug was also higher in SIPs as compared to controls. The immunoexpression of E-cadherin was significantly lower in SNCs group as compared with SIPs and controls, but no statistically significant difference in E-cadherin immunoexpression was noted between SIPs and control cases. There were statistically significant negative correlations between immunoexpression of Slug vs E-cadherin, E-cadherin vs fibronectin and positive correlation between Slug vs fibronectin in SNC. Statistically significant correlation between Slug and fibronectin immunoexpression in SIPs was also found. In conclusion, our findings suggest that relationships between Slug, E-cadherin and fibronectin could potentially point to EMT in the sinonasal cancer. Lack of correlation between EMT-related proteins in tested SIPs could reflect a benign nature of those cases.

Altered expression of epithelial-to-mesenchymal transition proteins in extraprostatic prostate cancer

Epithelial to mesenchymal transition (EMT) of cancer cells involves loss of epithelial polarity and adhesiveness, and gain of invasive and migratory mesenchymal behaviours. EMT occurs in prostate cancer (PCa) but it is unknown whether this is in specific areas of primary tumours. We examined whether any of eleven EMT-related proteins have altered expression or subcellular localisation within the extraprostatic extension component of locally advanced PCa compared with other localisations, and whether similar changes may occur in in vitro organotypic PCa cell cultures and in vivo PCa models. Expression profiles of three proteins (E-cadherin, Snail, and α-smooth muscle actin) were significantly different in extraprostatic extension PCa compared with intra-prostatic tumour, and 18/27 cases had an expression change of at least one of these three proteins. Of the three significantly altered EMT proteins in pT3 samples, one showed similar significantly altered expression patterns in in vitro organotypic culture models, and two in in vivo Pten-/- model samples. These results suggest that changes in EMT protein expression can be observed in the extraprostatic extension component of locally invasive PCa. The biology of some of these changes in protein expression may be studied in certain in vitro and in vivo PCa models.

Significance of TNF-α and the Adhesion Molecules: L-Selectin and VCAM-1 in Papillary Thyroid Carcinoma

Circulating levels of TNF-α and the adhesion molecules L-Selectin and VCAM-1 as well as their expression in the primary tumors of patients with benign thyroid diseases and papillary thyroid carcinoma (PTC) have been determined in this study. The serum levels of TNF-α, L-Selectin, and VCAM-1 were significantly higher in patients with both benign thyroid diseases and PTC as compared to the healthy individuals. However, the levels of only TNF-α and L-Selectin, and not VCAM-1, were significantly higher in patients with PTC in comparison to those observed in patients with benign thyroid diseases. Further the expression of TNF-α and L-Selectin was also significantly higher in the primary tumors of PTC patients, relative to the benign thyroid diseases. The expression of L-Selectin and VCAM-1 significantly correlated with aggressive tumor behavior. In PTC patients, the circulating TNF-α levels significantly positively correlated with the levels of L-Selectin, while TNF-α immunoreactivity was significantly associated with VCAM-1 expression. Serum TNF-α was found to be a significant prognosticator for OS in PTC patients. Overall the results signify that the interaction between TNF-α and the adhesion molecules may have a role in thyroid carcinogenesis and understanding this complexity may offer potential therapeutic targets for better management of thyroid cancer.

Epithelial–mesenchymal transition in prostatic disease

A fully differentiated epithelium of the normal prostate gland allows epithelial cells to de-differentiate into mesenchymal-like derivatives via the process of epithelial–mesenchymal transition (EMT) and redifferentiate via the reverse process, mesenchymal–epithelial transition. This review discusses the phenotypic changes associated with EMT and its programming in the development of the two growth disorders of the aging prostate gland, benign prostatic hyperplasia and prostate adenocarcinoma. Considering the cellular heterogeneity that characterizes both conditions, identifying the transcriptional programming of the phenotypic framework defining EMT and its reverse process mesenchymal–epithelial transition in their pathological landscape will enable novel platforms for biomarker-driven therapeutics and their implementation in benign prostatic hyperplasia and prostate cancer.

Expression of Genes Involved in Cellular Adhesion and Extracellular Matrix Remodeling Correlates with Poor Survival of Patients with Renal Cancer

PURPOSE

Renal cell carcinoma is the most common highly metastatic kidney malignancy. Adhesion has a crucial role in the metastatic process. TGF (transforming growth factor)-β1 is a pleiotropic cytokine that influences cancerous transformation. We hypothesized that 1) changes in the expression of adhesion related genes may influence survival rate of patients with renal cell carcinoma and 2) TGF-β1 may contribute to changed expression of adhesion related genes.

MATERIALS AND METHODS

Two-step quantitative real-time polymerase chain reaction arrays were used to analyze the expression of adhesion related genes in 77 tumors and matched pair controls. The prognostic significance of genes was evaluated in TCGA (The Cancer Genome Atlas) data on 468 patients with renal cell carcinoma. Quantitative real-time polymerase chain reaction and Western blot were applied for TGF-β1 analysis. TGF-β1 mediated regulation of gene expression was analyzed by TGF-β1 supplementation of Caki-2 cells and quantitative real-time polymerase chain reaction.

RESULTS

The expression of 19 genes related to adhesion and extracellular matrix remodeling was statistically significantly disturbed in renal cell carcinoma compared with controls. The 10-gene expression signature (COL1A1, COL5A1, COL11A1, FN1, ICAM1, ITGAL, ITGAM, ITGB2, THBS2 and TIMP1) correlated with poor survival (HR 2.85, p = 5.7e-10). TGF-β1 expression was 22 times higher in renal cell carcinoma than in controls (p <0.0001). TGF-β1 induced expression of TGFBI, COL1A1, COL5A1, COL8A1, FN1, ITGA5, ITGAM and TIMP1 in a renal cell carcinoma derived cell line.

CONCLUSIONS

Disturbed expression of genes involved in adhesion and extracellular matrix remodeling develops early during renal cell carcinoma carcinogenesis and correlates with poor survival. TGF-β1 contributes to changed expression of extracellular matrix and adhesion related genes. Bioinformatic analysis performed on a broad panel of cancers of nonkidney origin suggests that disturbed expression of genes related to extracellular matrix and adhesion may be a universal feature of cancerous progression.

Photo-thermal effect enhances the efficiency of radiotherapy using Arg-Gly-Asp peptides-conjugated gold nanorods that target αvβ3 in melanoma cancer cells

BACKGROUND

Thermotherapy has been known to be one of the most effective adjuvants to radiotherapy (RT) in cancer treatment, but it is not widely implemented clinically due to some limitations, such as, inadequate temperature concentrations to the tumor tissue, nonspecific and non-uniform distribution of heat. So we constructed arginine-glycine-aspartate peptides-conjugated gold nanorods (RGD-GNRs) that target the alpha(v) beta(3) Integrin (αvβ3) and investigate whether the photo-thermal effect of RGD-GNRs by near infrared radiation (NIR) could enhance the efficiency of RT in melanoma cancer cells.

RESULTS

RGD-GNRs could be seen both on the surface of the cell membranes and cytoplasm of A375 cells with high expression of αvβ3. After exposed to 808 nm NIR, RGD-GNRs with various concentrations could be rapidly heated up. Compared to other treatments, flow cytometric analysis indicated that RT + NIR + RGD-GNRs increased apoptosis (p < 0.001) and decreased the proportion of cells in the more radioresistant S phase (p = 0.014). Treated with NIR + RGD-GNRs, the radiosensitivity was also significantly enhanced (DMFSF2: 1.41).

CONCLUSION

Results of the current study showed the feasibility of using RGD-GNRs for synergetic RT with photo-thermal therapy. And it would greatly benefit the therapeutic effects of refractory or recurrent malignant cancers.

[Role of cadherins in health and in developing breast cancer]

The review gives data on the structure of cadherin cell adhesion molecules, their role in the body's development and malignant tumor progression. It describes cadherins that are considered to play the most important role in the development of a tumor process: E-, P-, and N-cadherins that belong to type I classical cadhedrins and VE-cadhedrin that does to type II cadherins. Particular emphasis is placed on the signal mechanisms with involvement of cadherins and cadherin-related molecules, which are realized in the body in health and in tumor transformation of cells.

Process of hepatic metastasis from pancreatic cancer: biology with clinical significance

PURPOSE

Pancreatic cancer shows a remarkable preference for the liver to establish secondary tumors. Selective metastasis to the liver is attributed to the development of potential microenvironment for the survival of pancreatic cancer cells. This review aims to provide a full understanding of the hepatic metastatic process from circulating pancreatic cancer cells to their settlement in the liver, serving as a basic theory for efficient prediction and treatment of metastatic diseases.

METHODS

A systematic search of relevant original articles and reviews was performed on PubMed, EMBASE and Cochrane Library for the purpose of this review.

RESULTS

Three interrelated phases are delineated as the contributions of the interaction between pancreatic cancer cells and the liver to hepatic metastasis process. Chemotaxis of disseminated pancreatic cancer cells and simultaneous defensive formation of platelets or neutrophils facilitate specific metastasis toward the liver. Remodeling of extracellular matrix and stromal cells in hepatic lobules and angiogenesis induced by proangiogenic factors support the survival and growth of clinical micrometastasis colonizing the liver. The bimodal role of the immune system or prevalence of cancer cells over the immune system makes metastatic progression successfully proceed from micrometastasis to macrometastasis.

CONCLUSIONS

Pancreatic cancer is an appropriate research object of cancer metastasis representing more than a straight cascade. If any of the successive or simultaneous phases, especially tumor-induced immunosuppression, is totally disrupted, hepatic metastasis will be temporarily under control or even cancelled forever. To shrink cancers on multiple fronts and prolong survival for patients, novel oral or intravenous anti-cancer agents covering one or different phases of metastatic pancreatic cancer are expected to be integrated into innovative strategies on the premise of safety and efficacious biostability.

Osteoblast-derived WNT-induced secreted protein 1 increases VCAM-1 expression and enhances prostate cancer metastasis by down-regulating miR-126

Bone metastases of prostate cancer (PCa) may cause intractable pain. Wnt-induced secreted protein-1 (WISP-1) belongs to the CCN family (CTGF/CYR61/NOV) that plays a key role in bone formation. We found that osteoblast-conditioned medium (OBCM) stimulates migration and vascular cell adhesion molecule-1 (VCAM-1) expression in human PCa (PC3 and DU145) cells. Osteoblast transfection with WISP-1 shRNA reduced OBCM-mediated PCa migration and VCAM-1 expression. Stimulation of PCa with OBCM or WISP-1 elevated focal adhesion kinase (FAK) and p38 phosphorylation. Either FAK and p38 inhibitors or siRNA abolished osteoblast-derived WISP-1-induced migration and VCAM-1 expression. Osteoblast-derived WISP-1 inhibited miR-126 expression. Moreover, miR-216 mimic reversed the WISP-1-enhanced migration and VCAM-1 expression. This study suggests that osteoblast-derived WISP-1 promotes migration and VCAM-1 expression in human PCa cells by down-regulating miR-126 expression via αvβ1 integrin, FAK, and p38 signaling pathways. Thus, WISP-1 may be a new molecular therapeutic target in PCa bone metastasis.

T-Cadherin Expression in Melanoma Cells Stimulates Stromal Cell Recruitment and Invasion by Regulating the Expression of Chemokines, Integrins and Adhesion Molecules

T-cadherin is a glycosyl-phosphatidylinositol (GPI) anchored member of the cadherin superfamily involved in the guidance of migrating cells. We have previously shown that in vivo T-cadherin overexpression leads to increased melanoma primary tumor growth due to the recruitment of mesenchymal stromal cells as well as the enhanced metastasis. Since tumor progression is highly dependent upon cell migration and invasion, the aim of the present study was to elucidate the mechanisms of T-cadherin participation in these processes. Herein we show that T-cadherin expression results in the increased invasive potential due to the upregulated expression of pro-oncogenic integrins, chemokines, adhesion molecules and extracellular matrix components. The detected increase in chemokine expression could be responsible for the stromal cell recruitment. At the same time our previous data demonstrated that T-cadherin expression inhibited neoangiogenesis in the primary tumors. We demonstrate that T-cadherin overexpression leads to the increase in the expression of anti-angiogenic molecules and reduction in pro-angiogenic factors. Thus, T-cadherin plays a dual role in melanoma growth and progression: T-cadherin expression results in anti-angiogenic effects in melanoma, however, this also stimulates transcription of genes responsible for migration and invasion of melanoma cells.

Connective tissue growth factor inhibits gastric cancer peritoneal metastasis by blocking integrin α3β1-dependent adhesion

BACKGROUND

Connective tissue growth factor (CTGF) plays important roles in normal and pathological conditions. The aim of this study was to investigate the role of CTGF in peritoneal metastasis as well as the underlying mechanism in gastric cancer progression.

METHODS

CTGF expression levels for wild-type and stable overexpression clones were determined by Western blotting and quantitative polymerase chain reaction (Q-PCR). Univariate and multivariate analyses, immunohistochemistry, and survival probability analyses were performed on gastric cancer patients. The extracellular matrix components involved in CTGF-regulated adhesion were determined. Recombinant CTGF was added to cells or coinoculated with gastric cancer cells into mice to evaluate its therapeutic potential.

RESULTS

CTGF overexpression and treatment with the recombinant protein significantly inhibited cell adhesion. In vivo peritoneal metastasis demonstrated that CTGF-stable transfectants markedly decreased the number and size of tumor nodules in the mesentery. Statistical analysis of gastric cancer patient data showed that patients expressing higher CTGF levels had earlier TNM staging and a higher survival probability after the surgery. Integrin α3β1 was the cell adhesion molecule mediating gastric cancer cell adhesion to laminin, and blocking of integrin α3β1 prevented gastric cancer cell adhesion to recombinant CTGF. Coimmunoprecipitation results indicated that CTGF binds to integrin α3. Coinoculation of recombinant CTGF and gastric cancer cell lines in mice showed effective inhibition of peritoneal dissemination.

CONCLUSIONS

Our results suggested that gastric cancer peritoneal metastasis is mediated through integrin α3β1 binding to laminin, and CTGF effectively blocks the interaction by binding to integrin α3β1, thus demonstrating the therapeutic potential of recombinant CTGF in gastric cancer patients.

Overexpression of δ-catenin is associated with a malignant phenotype and poor prognosis in colorectal cancer

Little is known regarding the expression or clinical significance of δ-catenin, a member of the catenin family, in colorectal cancer (CRC). The present study examined the expression of δ-catenin using immunohistochemistry in 110 cases of CRC, including 70 cases with complete follow-up records and 40 cases with paired lymph node metastases. In addition, δ-catenin mRNA and protein expression were compared in 30 pairs of matched CRC and normal colorectal tissues by reverse transcription quantitative polymerase chain reaction and western blot analysis. δ-Catenin was weakly expressed or absent in the cytoplasm of normal intestinal epithelial cells, whereas positive δ-catenin expression local-ized to the cytoplasm was observed in CRC cells. The rate of positive δ-catenin expression in CRC (68.18%; 75/110) was significantly higher than that in normal colorectal tissues (36.7%; 11/30; P<0.001). In addition, δ-catenin mRNA and protein expression were significantly increased in CRC tissues compared to those in their matched normal tissues (all P<0.05). The expression of δ-catenin in stage III–IV CRC was higher than that in stage I–II CRC, and the expression of δ-catenin in the tumors of patients with lymph node metastases was higher than that in patients without lymph node metastases. Kaplan-Meier survival curves demonstrated that the survival time of patients with positive δ-catenin expression was shorter than that of patients with negative δ-catenin expression (P=0.005). Furthermore, Cox multivariate analysis indicated that the tumor, nodes and metastasis stage (P=0.02) and positive δ-catenin expression (P=0.033) were independent prognostic factors in CRC. The present study therefore indicated that δ-catenin may be a suitable independent prognostic factor for CRC.

Anti-metastatic effect of jolkinolide B and the mechanism of activity in breast cancer MDA-MB-231 cells

Tumor metastasis is the main cause of mortality in cancer patients. However, no effective therapies are currently available to prevent metastasis. Cell adhesion to the extracellular matrix (ECM) is crucial in cancer progression and metastasis. Thus, suppression of cell adhesion may be an effective therapeutic strategy for the prevention of metastasis. In the present study, the anti-adhesion and anti-invasion effects of jolkinolide B, a diterpenoid compound from Euphorbia fischeriana Steud, that were exerted through suppression of β₁-integrin expression and phosphorylation of focal adhesion kinase (FAK) were examined in human breast cancer MDA-MB-231 cells. Jolkinolide B inhibited the adhesion of MDA-MB-231 cells to fibronectin but not to poly-L-lysine. In addition, jolkinolide B inhibited extracellular signal-regulated kinase (ERK) phosphorylation. U0126, an ERK inhibitor, also suppressed the invasion and adhesion of MDA-MB-231 cells. Overall, the present data demonstrated that jolkinolide B is a novel inhibitor of FAK-mediated signaling pathways that is involved in decreasing cell adhesion and invasion. Mitogen-activated protein kinase/ERK kinase may play a critical role in these effects, indicating that jolkinolide B possesses therapeutic potential for the treatment of breast cancer metastasis.

Association between the expression of T-cadherin and vascular endothelial growth factor and the prognosis of patients with gastric cancer

T-cadherin has been identified as a tumor-suppressor gene in several types of cancer. The present study aimed to investigate the association of the expression of T-cadherin with angiogenesis, and to evaluate its prognostic value for patients with primary gastric cancer. Gastric cancer tissues and matched adjacent tissues from 166 patients receiving surgical resection were included in the present study. The expression of T-cadherin was detected using immunohistochemistry, western blotting and reverse transcription-quantitative polymerase chain reaction. The expression of vascular epidermal growth factor (VEGF) was detected using immunohistochemistry, and its association with the expression of T-cadherin was analyzed. In addition, the association between the expression of T-cadherin and clinicopathological features were analyzed. The mRNA and protein expression levels of T-cadherin were significantly lower in the gastric cancer tissue compared with the corresponding adjacent normal tissue (P<0.05). The expression of VEGF was not associated with the expression of T-cadherin in the gastric cancer tissue. The decreased protein expression of T-cadherin correlated with smoking, larger tumor size (diameter, >4 cm), lymph node metastasis and a higher tumor-lymph node-metastasis stage (P<0.05 or P<0.01). However, the expression of T-cadherin was not correlated with gender, age, alcohol intake, Helecobacter pylori infection or differentiation (P>0.05). The multivariate analysis demonstrated that the expression of T-cadherin was an independent prognostic factor for the overall survival rate of patients with gastric cancer. This data suggested that the downregulation of T-cadherin may contribute to gastric cancer progression, representing a useful biomarker for predicting the biological behavior and prognosis of gastric cancer. However, no significant association was observed between the expression of VEGF and T-cadherin.

Inhibitory effects of proton beam irradiation on integrin expression and signaling pathway in human colon carcinoma HT29 cells

Proton radiotherapy has been established as a highly effective modality used in the local control of tumor growth. Although proton radiotherapy is used worldwide to treat several types of cancer clinically with great success due to superior targeting and energy deposition, the detailed regulatory mechanisms underlying the functions of proton radiation are not yet well understood. Accordingly, in the present study, to assess the effects of proton beam on integrin-mediated signaling pathways, we investigated the expression of integrins related to tumor progression and integrin trafficking, and key molecules related to cell adhesion, as well as examining phosphorylation of signaling molecules involved in integrin-mediated signaling pathways. Proton beam irradiation inhibited the increase in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced integrin β1 protein expression and the gene expression of members of the integrin family, such as α5β1, α6β4, αvβ3, and αvβ6 in human colorectal adenocarcinoma HT-29 cells. Simultaneously, the gene expression of cell adhesion molecules, such as FAK and CDH1, and integrin trafficking regulators, such as RAB4, RAB11, and HAX1, was decreased by proton beam irradiation. Moreover, proton beam irradiation decreased the phosphorylation of key molecules involved in integrin signaling, such as FAK, Src, and p130Cas, as well as PKC and MAPK, which are known as promoters of cell migration, while increased the phosphorylation of AMPK and the gene expression of Rab IP4 involved in the inhibition of cell adhesion and cell spreading. Taken together, our findings suggest that proton beam irradiation can inhibit metastatic potential, including cell adhesion and migration, by modulating the gene expression of molecules involved in integrin trafficking and integrin-mediated signaling, which are necessary for tumor progression.

Whole exome sequencing of a patient with metastatic hidradenocarcinoma and review of the literature

Hidradenocarcinoma is a rare malignancy of the sweat glands with only a few cases reported in literature. The management of these tumors is based on the extent of disease with local disease managed with surgical resection. These can tumors carry a high potential of lymphatic and vascular spread and local and distant metastases are not uncommon. Given the rarity of the tumor and lack of genetic and clinical data about these tumors, there is no consensus on the proper management of metastatic disease. Here in we report the first case of metastatic hidradenocarcinoma with detailed molecular profiling including whole exome sequencing. We identified mutations in multiple genes including two that are potentially targetable: PTCH1 and TCF7L1. Further work is necessary to not only confirm the presence of these mutations but also to confirm the clinical significance.

Clinical significance of E-cadherin and Vimentin expression in Han and Uygur colon cancer patients from Xinjiang

AIM: To detect the expression of E-cadherin and Vimentin in colon cancer and to analyze their clinical significance.

METHODS: Immunohistochemistry was adopted to detect the expression of E-cadherin and Vimentin in colon cancer specimens and tumor-adjacent colonic mucosa tissue specimens from 41 Uygur and 58 Han patients with pathologically diagnosed colon cancer. The relationship between E-cadhertin and Vimentin expression and clinicopathological factors was analyzed.

RESULTS: The percentages of patients with young/middle age, poor differentiation, lymph node metastasis, and distant metastasis were significantly different between Uygur and Han patients (68.3% vs 43.1%, 73.2% vs 48.3%, 70.7% vs 48.3%, 36.6% vs 15.5%, P < 0.05). The positive rates of E-cadherin and Vimentin expression in colon cancer tissues did not differ significantly between Han and Uygur patients (87.8% vs 86.2%, 9.76% vs 3.45%, P > 0.05), although significant differences were noted between colon cancer and normal colon mucosa tissues (100% and 0%) (P < 0.05). There was a negative correlation between E-cadherin and Vimentin expression (r = -0.81, P < 0.05). The expression of E-cadherin was correlated with tumor differentiation, lymph node metastasis, distant metastasis and TNM stage (P < 0.05). The expression of Vimentin was correlated with lymph node metastasis, distant metastasis and TNM stage (P < 0.05).

CONCLUSION: Epithelial-mesenchymal transition (EMT) occurs in colon cancer. Simultaneous detection of E-cadherin and Vimentin expression may help assess EMT in colon cancer tissue and predict recurrence and metastasis.

Estrogen-dependent sushi domain containing 3 regulates cytoskeleton organization and migration in breast cancer cells

Aromatase inhibitors (AIs) are the standard endocrine therapy for postmenopausal breast cancer; however, currently used biomarkers, such as, estrogen receptor-alpha/progesterone receptor (ERα/PR), predict only slightly more than half of the potential responders to AI treatment. To identify novel markers of AI responsiveness, a genome-wide microarray analysis was performed using primary breast tumor samples from 50 postmenopausal women who later developed metastatic breast cancer. Sushi domain containing 3 (SUSD3) is a significantly differentially expressed gene, with 3.38-fold higher mRNA levels in AI-responsive breast tumors vs non-responders (P<0.001). SUSD3 was highly expressed in ERα-positive breast tumors and treatment with estradiol increased SUSD3 expression in ERα-positive breast cancer cells. Treatment with an antiestrogen or ERα knockdown abolished basal and estradiol-dependent SUSD3 expression. Recruitment of ERα upstream of the transcription start site of SUSD3 was demonstrated by chromatin immunoprecipitation-PCR. Flow cytometric analysis of SUSD3-knockdown cells revealed blunted estradiol effects on progression into S and M phases. SUSD3 was localized to the plasma membrane of breast cancer cells. SUSD3 knockdown decreased the appearance of actin-rich protrusions, stress fibers and large basal focal adhesions, while increasing the presence of cortical actin concomitant with a decrease in Rho and focal adhesion kinase activity. SUSD3-deficient cells demonstrated diminished cell spreading, cell-cell adhesion and motility. In conclusion, SUSD3 is a novel promoter of estrogen-dependent cell proliferation and regulator of cell-cell and cell-substrate interactions and migration in breast cancer. It may serve as a novel predictor of response to endocrine therapy and potential therapeutic target.

Collagen triple helix repeat containing 1 (CTHRC1) acts via ERK-dependent induction of MMP9 to promote invasion of colorectal cancer cells

Collagen triple helix repeat-containing 1 (CTHRC1) is known to be aberrantly upregulated in most human solid tumors, although the functional roles of CTHRC1 in colorectal cancer remain unclear. In this study, we investigated the occurrence of CTHRC1 upregulation and its role in vivo and in vitro. The expression profile and clinical importance of CTHRC1 were examined by reverse transcription-polymerase chain reaction and immunohistochemical analyses in normal and tumor patient samples. CTHRC1 was detectable in normal tissues, but also was highly expressed in tumor specimens. CTHRC1 upregulation was significantly associated with demethylation of the CTHRC1 promoter in colon cancer cell lines and tumor tissues. Clinicopathologic analyses showed that nodal status and expression of CTHRC1 (95% CI 0.999-3.984, p=0.05) were significant prognostic factors for disease-free survival. Promoter CpG methylation and hypermethylation status were measured by bisulfite sequencing and pyrosequencing analysis. Furthermore, we showed that overexpression of CTHRC1 in the SW480 and HT-29 cell lines increased invasiveness, an effect mediated by extracellular signal-regulated kinase (ERK)-dependent upregulation of matrix metalloproteinase 9 (MMP9). Consistent with this, we found that knockdown of CTHRC1 attenuated ERK activation and cancer cell invasivity. These results demonstrate that CTHRC1 expression is elevated in human colon cancer cell lines and clinical specimens, and promotes cancer cell invasivity through ERK-dependent induction of MMP9 expression. Our results further suggest that high levels of CTHRC1 expression are associated with poor clinical outcomes.

Role of the interaction between galectin-3 and cell adhesion molecules in cancer metastasis

Galectin-3, a unique chimera-type member of the β-galactoside-binding soluble lectin family, is present in both normal and cancer cells and plays a crucial role in the regulation of cell adhesion. It is involved both in accelerating detachment of cells from primary tumor sites and promoting cancer cell adhesion and survival to anoikis in the blood stream. Cell adhesion molecules (CAMs) are membrane receptors that mediate cell-cell and cell-matrix interactions, and are essential for transducing intracellular signals responsible for adhesion, migration, invasion, angiogenesis, and organ-specific metastasis. This review will discuss the recent advances in our understanding the biological functions, mechanism and therapeutic implication of the interaction between galectin-3 and CAMs in cancer metastasis.

Cancer cells remodel themselves and vasculature to overcome the endothelial barrier

Metastasis refers to the spread of cancer cells from a primary tumor to distant organs mostly via the bloodstream. During the metastatic process, cancer cells invade blood vessels to enter circulation, and later exit the vasculature at a distant site. Endothelial cells that line blood vessels normally serve as a barrier to the movement of cells into or out of the blood. It is thus critical to understand how metastatic cancer cells overcome the endothelial barrier. Epithelial cancer cells acquire increased motility and invasiveness through epithelial-to-mesenchymal transition (EMT), which enables them to move toward vasculature. Cancer cells also express a variety of adhesion molecules that allow them to attach to vascular endothelium. Finally, cancer cells secrete or induce growth factors and cytokines to actively prompt vascular hyperpermeability that compromises endothelial barrier function and facilitates transmigration of cancer cells through the vascular wall. Elucidation of the mechanisms underlying metastatic dissemination may help develop new anti-metastasis therapeutics.

The significance of genetics for cholangiocarcinoma development

Cholangiocarcinoma (CCA) is a rare malignancy of the liver, arising from bile ducts. The incidence is increasing worldwide, but the prognosis has remained dismal and virtually unchanged in the past 30 years. Although several risk factors have been associated with the development of this cancer, none of them are normally identified in most patients. Diagnosis in advanced stages of the disease and limited therapeutic options contribute to poor survival rates. The recent analysis of genetic and epigenetic alterations occurring in CCA has shed new light in the understanding of the molecular mechanisms leading to the malignant transformation of biliary cells. Further studies in this direction may foster new diagnostic, prognostic and therapeutic approaches. This review provides a global overview of recent advances in CCA and describes the most important genetic mutations and epigenetic alterations so far reported in CCA.

Drug repositioning discovery for early- and late-stage non-small-cell lung cancer

Drug repositioning is a popular approach in the pharmaceutical industry for identifying potential new uses for existing drugs and accelerating the development time. Non-small-cell lung cancer (NSCLC) is one of the leading causes of death worldwide. To reduce the biological heterogeneity effects among different individuals, both normal and cancer tissues were taken from the same patient, hence allowing pairwise testing. By comparing early- and late-stage cancer patients, we can identify stage-specific NSCLC genes. Differentially expressed genes are clustered separately to form up- and downregulated communities that are used as queries to perform enrichment analysis. The results suggest that pathways for early- and late-stage cancers are different. Sets of up- and downregulated genes were submitted to the cMap web resource to identify potential drugs. To achieve high confidence drug prediction, multiple microarray experimental results were merged by performing meta-analysis. The results of a few drug findings are supported by MTT assay or clonogenic assay data. In conclusion, we have been able to assess the potential existing drugs to identify novel anticancer drugs, which may be helpful in drug repositioning discovery for NSCLC.