High EpCAM expression is linked to proliferation and lauren classification in gastric cancer

Regulation of the Function and Expression of EpCAM

The epithelial cell adhesion molecule (EpCAM) is a single transmembrane protein on the cell surface. Given its strong expression on epithelial cells and epithelial cell-derived tumors, EpCAM has been identified as a biomarker for circulating tumor cells (CTCs) and exosomes and a target for cancer therapy. As a cell adhesion molecule, EpCAM has a crystal structure that indicates that it forms a cis-dimer first and then probably a trans-tetramer to mediate intercellular adhesion. Through regulated intramembrane proteolysis (RIP), EpCAM and its proteolytic fragments are also able to regulate multiple signaling pathways, Wnt signaling in particular. Although great progress has been made, increasingly more findings have revealed the context-specific expression and function patterns of EpCAM and their regulation processes, which necessitates further studies to determine the structure, function, and expression of EpCAM under both physiological and pathological conditions, broadening its application in basic and translational cancer research.

The Role of Additional Staining in the Assessment of the Peritoneal Regression Grading Score (PRGS) in Peritoneal Metastasis of Gastric Origin

INTRODUCTION

The Peritoneal Regression Grading Score (PRGS) is a 4-tied histologic regression grading score for determining the response of peritoneal metastasis to chemotherapy. Peritoneal biopsies in every abdominal quadrant are recommended. A positive therapy response is defined as a decreasing or stable mean PRGS between 2 therapy cycles. The added value of periodic acid satin (PAS) and Ber-EP4 staining over HE staining for diagnosing PRGS1 (the absence of vital tumor cells) is unclear.

MATERIALS AND METHODS

A total of 339 biopsies obtained during 76 laparoscopies in 33 patients with peritoneal metastasis of gastric cancer were analyzed. Biopsies classified as PRGS 1 (no residual tumor, n=95) or indefinite (n=50) were stained with PAS, and remaining indefinite or PRGS1 cases additionally stained with BerEP4.

RESULTS

After PAS-staining tumor cells were detected in 28 out of 145 biopsies (19%), the remaining 117 biopsies were immunostained with Ber-EP4. Tumor cells were detected in 22 biopsies (19%). In total, additional staining allowed the detection of residual tumor cells in 50 out of 339 biopsies (15%) and changed the therapy response assessment in 7 out of 33 (21%) patients.

CONCLUSIONS

In summary, 25% (24 out of 95) of initially tumor-free samples (PRGS1) showed residual tumor cells after additional staining with PAS and/or BerEp4. Immunohistochemistry provided important additional information (the presence of tumor cells) in 22 of all 339 biopsies (11.2%). Further staining reduced the instances of unclear diagnosis from 50 to 0 and changed the therapy response assessment in 7 out of 33 patients (21%). We recommend additional staining in PRGS1 or unclear cases.

Functional Implications of the Dynamic Regulation of EpCAM during Epithelial-to-Mesenchymal Transition

Epithelial cell adhesion molecule (EpCAM) is a transmembrane glycoprotein expressed in epithelial tissues. EpCAM forms intercellular, homophilic adhesions, modulates epithelial junctional protein complex formation, and promotes epithelial tissue homeostasis. EpCAM is a target of molecular therapies and plays a prominent role in tumor biology. In this review, we focus on the dynamic regulation of EpCAM expression during epithelial-to-mesenchymal transition (EMT) and the functional implications of EpCAM expression on the regulation of EMT. EpCAM is frequently and highly expressed in epithelial cancers, while silenced in mesenchymal cancers. During EMT, EpCAM expression is downregulated by extracellular signal-regulated kinases (ERK) and EMT transcription factors, as well as by regulated intramembrane proteolysis (RIP). The functional impact of EpCAM expression on tumor biology is frequently dependent on the cancer type and predominant oncogenic signaling pathways, suggesting that the role of EpCAM in tumor biology and EMT is multifunctional. Membrane EpCAM is cleaved in cancers and its intracellular domain (EpICD) is transported into the nucleus and binds β-catenin, FHL2, and LEF1. This stimulates gene transcription that promotes growth, cancer stem cell properties, and EMT. EpCAM is also regulated by epidermal growth factor receptor (EGFR) signaling and the EpCAM ectoderm (EpEX) is an EGFR ligand that affects EMT. EpCAM is expressed on circulating tumor and cancer stem cells undergoing EMT and modulates metastases and cancer treatment responses. Future research exploring EpCAM’s role in EMT may reveal additional therapeutic opportunities.

Hepatocellular carcinoma: Intratumoral EpCAM-positive cancer stem cell heterogeneity identifies high-risk tumor subtype

BACKGROUND

The translational interest in the intratumoral heterogeneity of hepatocellular carcinoma (HCC) has been increasing. The dismal prognosis of this pathology is linked to the features of the HCC harbouring cancer stem cells (CSC), represented by EpCAM-expression. However, the extent of the impact of intratumoral distribution of CSC-features, both on the recurrence after curative resection and on clinical outcome, remains unknown. To address this, we investigated the spatial heterogeneity of CSC-features with the aim of identifying the unique HCC patient subgroups amenable to adjuvant treatment.

METHODS

We designed a tissue microarray (TMA) from patients who had received liver resection between 2011 and 2017. Tumor specimens were sampled at multiple locations (n = 3-8). EpCAM-positivity was assessed for intensity and proportion by applying a score dividing three groups: (i) negative (E-/-); (ii) heterogeneous (E-/+); and (iii) homogeneous (E+/+). The groups were further analysed with regard to time-to-recurrence (TTR) and recurrence-free-survival (RFS).

RESULTS

We included 314 tumor spots from 69 patients (76.8% male, median age 66, liver cirrhosis/fibrosis 75.8%). The risk factors were alcohol abuse (26.2%), NASH (13.1%), HBV (15.5%), HCV (17.9%) and others (27.4%), representative of a typical Western cohort. E+/+ patients experienced significantly shorter TTR and RFS compared to E+/- and E-/- patients (TTR 5 vs. 19 months, p = 0.022; RFS 5 vs. 14 vs. 21 months, p = 0.016). Only homogeneous EpCAM-positivity correlated with higher AFP levels (> 400 ng/ml, p = 0.031).

CONCLUSIONS

Spatial heterogeneity of EpCAM-expression was markedly present in the cohort. Of note, only homogeneous EpCAM-expression correlated significantly with early recurrence, whereas heterogeneous EpCAM-expression was associated with clinical endpoints comparable to EpCAM-negativity. We identified a unique HCC subtype associated with a high risk of tumor recurrence.

Epithelial Cell Adhesion Molecule: An Anchor to Isolate Clinically Relevant Circulating Tumor Cells

In the last few decades, the epithelial cell adhesion molecule (EpCAM) has received increased attention as the main membrane marker used in many enrichment technologies to isolate circulating tumor cells (CTCs). Although there has been a great deal of progress in the implementation of EpCAM-based CTC detection technologies in medical settings, several issues continue to limit their clinical utility. The biology of EpCAM and its role are not completely understood but evidence suggests that the expression of this epithelial cell-surface protein is crucial for metastasis-competent CTCs and may not be lost completely during the epithelial-to-mesenchymal transition. In this review, we summarize the most significant advantages and disadvantages of using EpCAM as a marker for CTC enrichment and its potential biological role in the metastatic cascade.

Enteroids expressing a disease-associated mutant of EpCAM are a model for congenital tufting enteropathy

Congenital tufting enteropathy (CTE) is an autosomal recessive disease characterized by severe intestinal failure in infancy and mutations in the epithelial cell adhesion molecule (EPCAM) gene. Previous studies of CTE in mice expressing mutant EpCAM show neonatal lethality. Hence, to study the cellular, molecular, and physiological alterations that result from EpCAM mutation, a tamoxifen-inducible mutant EpCAM enteroid model has been generated. The presence of mutant EpCAM in the model was confirmed at both mRNA and protein levels. Immunofluorescence microscopy demonstrated the reduced expression of mutant EpCAM. Mutant enteroids had reduced budding potential as well as significantly decreased mRNA expression for epithelial lineage markers (Mucin 2, lysozyme, sucrase-isomaltase), proliferation marker Ki67, and secretory pathway transcription factors (Atoh1, Hnf1b). Significantly decreased numbers of Paneth and goblet cells were confirmed by staining. These findings were correlated with intestinal tissue from CTE patients and the mutant mice model that had significantly fewer Paneth and goblet cells than in healthy counterparts. FITC-dextran studies demonstrated significantly impaired barrier function in monolayers derived from mutant enteroids compared with control monolayers. In conclusion, we have established an ex vivo CTE model. The role of EpCAM in the budding potential, differentiation, and barrier function of enteroids is noted. Our study establishes new facets of EpCAM biology that will aid in understanding the pathophysiology of CTE and role of EpCAM in health and disease.NEW & NOTEWORTHY Here, we develop a novel ex vivo enteroid model for congenital tufting enteropathy (CTE) based on epithelial cell adhesion molecule (EPCAM) gene mutations found in patients. With this model we demonstrate the role of EpCAM in maintaining the functional homeostasis of the intestinal epithelium, including differentiation, proliferation, and barrier integrity. This study further establishes a new direction in EpCAM biology that will help in understanding the detailed pathophysiology of CTE and role of EpCAM.

[Matrine suppresses stemness of hepatocellular carcinoma cells by regulating β-catenin signaling pathway]

OBJECTIVE

To explore the effects of matrine on the proliferation, tumor cell stemness, β-catenin transcriptional activity and AKT/GSK3β/β-catenin signaling pathway in human hepatocellular carcinoma (HCC) HepG2 and Huh7 cells.

METHODS

The proliferation and colony formation ability of HepG2 and Huh7 cells treated with 200, 400, and 800 μg/mL matrine were evaluated with MTT assay and colony formation assay, respectively. Real-time quantitative PCR was performed to detect the mRNA expressions of CD90, epithelial cell adhesion molecule (EpCAM) and CD133, and dual-luciferase assay was used to detect the transcriptional activity of β-catenin in the treated cells. The effects of matrine on the expressions of protein kinase B (AKT), P-AKT, GSK-3β, P-GSK-3β, P-β-catenin and β-catenin proteins in the Wnt/β-catenin signaling pathway were assessed using Western blotting.

RESULTS

Matrine inhibited the proliferation of the two HCC cell lines in a time- and concentration-dependent manner. The half-inhibitory concentrations of matrine were 2369, 1565 and 909.1 μg/mL at 24, 48 and 72 h in HepG2 cells, respectively, and were 1355, 781.8, and 612.8 μg/mL in Huh7 cells, respectively. Matrine concentrationdependently suppressed colony formation of the HCC cells, producing significant inhibitory effects at 400 μg/mL P < 0.01) and 800 μg/mL P < 0.001) in HepG2 cells and at 200 μg/mL P < 0.05), 400 μg/mL P < 0.01), and 800 μg/mL P < 0.001) in Huh7 cells. Matrine at 400 and 800 μg/mL significantly inhibited the mRNA expression of CD90, EpCAM and CD133 and the transcriptional level of β-catenin in both HepG2 and Huh7 cells P < 0.05 or 0.01). Matrine at 400 and 800 μg/mL also significantly decreased the protein levels of β-catenin, P-AKT and P-GSK-3β and increased the phosphorylation level of β-catenin in both of the cell lines.

CONCLUSIONS

Matrine inhibits the proliferation, colony formation, and the expressions of tumor stem cell markers CD90, EpCAM and CD133 in both HepG2 and Huh7 cells probably by inhibiting Wnt/β-catenin signaling pathway and the transcriptional activity ofβ-catenin.

Expression of EpCAM in adenoid cystic carcinoma

The mutational landscape of adenoid cystic carcinoma (ACC) is currently being revealed, but further studies are needed to identify biomarkers as therapeutic targets or prognostic factors of ACC. In this study, we investigated the expression of epithelial cell adhesion molecule (EpCAM) in ACCs. We retrospectively collected 83 cases of surgically resected ACCs. Using tissue microarray, we conducted immunohistochemical staining using the anti-EpCAM antibody. EpCAM expression was analysed by intensity score and the total immunostaining score. The positivity was 97.6% (81/83 cases), regardless of the intensity score. A higher histological grade (p = 0.006) and specific tumour location (non-salivary gland origin, p = 0.02) showed a correlation with higher EpCAM intensity. Higher EpCAM expression by total immunostaining score was associated with histological grade (p = 0.004), distant metastasis (p = 0.004) and poorer prognosis (overall survival p = 0.015 and progression-free survival p = 0.033). We suggest EpCAM as a candidate prognostic marker and a putative therapeutic target in ACC. Also, ACCs arising from salivary gland and non-salivary gland sites, respectively, might display different pathophysiologies in which EpCAM could play a role.

Identification of genes and genetic networks associated with BAG3‑dependent cell proliferation and cell survival in human cervical cancer HeLa cells

Bcl‑2‑associated athanogene (BAG) 3, is a member of the BAG protein family and a known co‑chaperone of heat shock protein (HSP) 70. BAG3 serves a role in regulating a variety of cellular functions, including cell growth, proliferation and cell death including apoptosis. BAG3 is a stress‑inducible protein, however the constitutive expression level of BAG3 is increased in cancer cells compared with healthy cells. Recent proteomics technology combined with bioinformatics has revealed that BAG3 participates in an interactome with a number of proteins other than its typical partner HSP70. The functional types represented in the interactome included nucleic acid binding proteins and transcription factors, as well as chaperones, which indicated that overexpression of BAG3 may contribute to proliferation and cell survival through the alteration of gene transcription. While an increasing number of studies have addressed the function of BAG3 as a co‑chaperone protein, BAG3‑dependent alteration of gene transcription has not been studied extensively. The present study established two BAG3 knockout human cervical cancer HeLa cell clones and addressed the role of BAG3 in cell proliferation and survival through gene transcription, using DNA microarray‑based transcriptome analysis and bioinformatics. The present study also identified two genetic networks associated with 'cellular growth and proliferation' and 'cell death and survival', which are dysregulated in the absence of BAG3, and may therefore be linked to BAG3 overexpression in cancer. These findings provide a molecular basis for understanding of BAG3‑dependent cell proliferation and survival from the aspect of alteration of gene expression.

Upregulation of LncRNA BCYRN1 promotes tumor progression and enhances EpCAM expression in gastric carcinoma

Brain cytoplasmic RNA 1 (BCYRN1), along non-coding RNA, plays a critical role in various diseases, including some cancers. However, the expression of BCYRN1 and its roles in gastric carcinoma (GC) still remain unidentified. Thus, this study employed RT-qPCR to detect expression of BCYRN1 in 85 paired GC samples and adjacent normal tissues, and performed in vitro studies to explore effects of BCYRN1 in GC cells on cell proliferation, apoptosis and migration. We found BCYRN1 was significantly upregulated in GC samples, and its expression was positively correlated with advanced TNM stage (p = 0.0012) and tumor size (p = 0.027). Functionally, BCYRN1 knockdown by siRNA could inhibit cell proliferation, induce G1/G0 cell cycle arrest, increase apoptosis and impair migratory ability of AGS cells. Moreover, the results of RT-qPCR and western blotting indicated that knockdown of BCYRN1 notably decreased the expression of epithelial cell adhesion molecules (EpCAM). Otherwise, overexpression of BCYRN1 in GC cells (BGC-823 and SGC-7901) could reverse the effects of BCYRN1 knockdown. Taken together, our data indicate for the first time that BCYRN1 acts as an oncogenic lncRNA in GC progression and may be a potential therapeutic target in GC.

CD24, CD44 and EpCAM enrich for tumour-initiating cells in a newly established patient-derived xenograft of nasopharyngeal carcinoma

Subpopulations of nasopharyngeal carcinoma (NPC) contain cells with differential tumourigenic properties. Our study evaluates the tumourigenic potential of CD24, CD44, EpCAM and combination of EpCAM/CD44 cells in NPC. CD44br and EpCAMbr cells enriched for higher S-phase cell content, faster-growing tumourigenic cells leading to tumours with larger volume and higher mitotic figures. Although CD44br and EpCAMbr cells significantly enriched for tumour-initiating cells (TICs), all cells could retain self-renewal property for at least four generations. Compared to CD44 marker alone, EpCAM/CD44dbr marker did not enhance for cells with faster-growing ability or higher TIC frequency. Cells expressing high CD44 or EpCAM had lower KLF4 and p21 in NPC subpopulations. KLF4-overexpressed EpCAMbr cells had slower growth while Kenpaullone inhibition of KLF4 transcription increased in vitro cell proliferation. Compared to non-NPC, NPC specimens had increased expression of EPCAM, of which tumours from advanced stage of NPC had higher expression. Together, our study provides evidence that EpCAM is a potentially important marker in NPC.

Relationship between epithelial cell adhesion molecule (EpCAM) overexpression and gastric cancer patients: A systematic review and meta-analysis

OBJECTIVES

The epithelial cell adhesion molecule (EpCAM) is one of the most commonly used markers of cancer stem cells (CSCs), but the clinical and prognostic significance of EpCAM in gastric cancer (GC) remains disputable. Motivated by heterogeneous and inconclusive results, we conducted a systematic review and meta-analysis to systematically summarize and elucidate the association between EpCAM overexpression and GC patients.

METHODS

The PubMed, Cochrane Library, Medline, Web of Knowledge and the China National Knowledge Infrastructure (CNKI) databases were searched to identify relevant studies. The RevMan 5.3 software was used for the meta-analysis. Fixed-effects or random-effects models were applied depending on the presence of heterogeneity. The pooled odds ratio (ORs) and 95% confidence intervals (CIs) were applied to estimate the associations between EpCAM and gastric cancer. For the significant heterogeneity studies, sensitivity analyses were applied based on the population to test the robustness of the pooled results and identify possible sources of heterogeneity.

RESULTS

A total of 11 studies including 1960 GC patients met our inclusion criteria. The results of the meta-analyses revealed that there were significant differences in EpCAM overexpression and tumour size (OR = 2.97, 95% CI: 2.13~4.13, P < 0.00001), the nature of the tissue (OR = 80.30, 95% CI: 29.21~220.81, P < 0.00001), lymph node metastasis (OR = 2.78, 95% CI: 1.23~6.27, P = 0.01), and the cumulative 5-year overall survival rate (OR = 0.54, 95% CI:0.29~0.99, P = 0.05). No significant associations were identified between EpCAM overexpression and gender (OR = 0.89, 95% CI: 0.66~1.19, P = 0.43), age (OR = 1.13, 95% CI: 0.58~2.20, P = 0.73), tumour stage (OR = 2.26, 95% CI: 0.79~6.45, P = 0.13), distant metastasis (OR = 2.15, 95% CI: 0.20~22.69, P = 0.52), TNM stage (OR = 5.14, 95% CI: 0.77~34.37, P = 0.09), Lauren type (OR = 1.18, 95% CI: 0.08~16.45, P = 0.9), differentiation (OR = 1.88, 95% CI: 0.65~5.41, P = 0.24). However, due to significant heterogeneity in tumor stage, lymph node metastasis, TNM stage, differentiation and Lauren type, these results should be taken carefully.

CONCLUSIONS

The meta-analysis demonstrated that the expression of EpCAM in the gastric cancer group was greater than that in the control group. Moreover, EpCAM overexpression was associated with larger tumour size, lymphnode metastasis and worse prognosis in gastric cancer. Due to significant heterogeneity, the sensitivity analysis suggests that population factor may be an important source of heterogeneity, and these results should be treated with caution. EpCAM may be useful as a novel prognostic factor, and large-scale and well-designed studies are needed to validate our results in the future.

Immunohistochemical expression of epithelial cell adhesion molecule (EpCAM) in mucoepidermoid carcinoma compared to normal salivary gland tissues

OBJECTIVES

Mucoepidermoid carcinoma (MEC) is the most common malignant salivary gland tumor which displays biological, histological and clinical diversity thus representing a challenge for its diagnosis and management. Epithelial cell adhesion molecule (EpCAM) is a transmembrane glycoprotein identified as a tumor specific antigen due to its frequent overexpression in the majority of epithelial carcinomas and its correlation with prognosis. It is considered to be a promising biomarker used as a therapeutic target already in ongoing clinical trials. The purpose of this study was to investigate the pattern, cellular characterization and level of EpCAM expression in MEC and demonstrate its correlation with histologic grading which may benefit future clinical trials using EpCAM targeted therapy.

MATERIALS AND METHODS

48 specimens (12 normal salivary gland tissue and 36 MEC) were collected and EpCAM membranous expression was evaluated by immunohistochemistry. Total immunoscore (TIS) was evaluated, the term 'EpCAM overexpression' was given for tissues showing a total immunoscore >4.

RESULTS

A highly significant difference was observed between TIS percent values in control and different grades of MEC (p<0.001). High grade MEC (HG-MEC) was the highest EpCAM expressor. In addition, EpCAM expression pattern differed among the different grades.

CONCLUSION

EpCAM expression was detected in MEC, and its overexpression correlated with increasing the histological grade. The diffuse membranous expression in HG-MEC could be of diagnostic value in relation to the patchy expression observed in both low grade and intermediate grade MEC.

By inhibiting Ras/Raf/ERK and MMP-9, knockdown of EpCAM inhibits breast cancer cell growth and metastasis

Epithelial cell adhesion molecule (EpCAM) is a type I transmembrane protein that is expressed in the majority of normal epithelial tissues and is overexpressed in most epithelial cancers including breast cancer, where it plays an important role in cancer progression. However, the mechanism by which EpCAM promotes the progression of breast cancer is not understood. In this study, we found that EpCAM expression was increased in tumor tissue from breast cancer patients compared to healthy patients. Overexpression of EpCAM in breast cancer cells enhanced tumor cell growth in vitro and increased invasiveness, whereas small interfering RNA-mediated silencing of EpCAM (si-EpCAM) had the opposite effect. EpCAM knockdown led to decreased phosphorylation of Raf and ERK, suppression of malignant behavior of breast cancer cells, and inhibition of the Ras/Raf/ERK signaling pathway. Furthermore, si-EpCAM-mediated invasion and metastasis of breast carcinoma cells required the downregulation of matrix metalloproteinase-9 (MMP-9) through inhibition of this signaling pathway. In conclusion, our data show that knockdown of EpCAM can inhibition breast cancer cell growth and metastasis via inhibition of the Ras/Raf/ERK signaling pathway and MMP-9.

High EZH2 expression is correlated to metastatic disease in pediatric soft tissue sarcomas

BACKGROUND

Enhancer of Zeste Drosophila Homologue 2 (EZH2) is a key regulator of transcription as a member of polycomb repressive complex 2 (PRC2) which exerts repression of downstream genes and is correlated to invasiveness and progression of different tumours. Therefore, we evaluated the expression of PRC2 proteins in pediatric soft tissue sarcoma (rhabdomyosarcoma, RMS and extraosseous Ewing sarcoma, EES) correlating them to the clinical outcome of the patients.

METHODS

We analyzed PRC2 protein expression by quantitative real time PCR, western blotting and immunohistochemistry in 17 soft tissue sarcomas (11 RMS and 6 EES) enrolled at Paediatric Oncology Units of the Second University of Naples. Expression analysis was performed for EZH2, SUZ12 and EED.

RESULTS

Enhancer of Zeste Drosophila Homologue 2 was expressed with a different degree in 60 % of samples. Interestingly, the magnitude of EZH2 up regulation was significantly higher in patients presenting lymph node and/or distant metastases at the diagnosis. Moreover, patients overexpressing EZH2 had a lower probability of survival compared to patients negative or with low EZH2 expression.

CONCLUSIONS

Our study suggests that high EZH2 expression is associated to increased aggressiveness of the disease. Therefore, drugs that control its activity could be potentially used in the epigenetic target treatment of tumors with these alterations.

Challenge and thought on treatment of diffuse gastric cancer

Diffuse gastric cancer, which has a high degree of malignancy and is metastasis-prone, is a pathological type of Lauren classification. The incidence of diffuse gastric cancer shows an increasing trend in China, and it greatly threatens the human health. There have been many studies on diffuse gastric cancer, and its treatment and prognosis have been improved to some extent. In this paper, we systematically describe diffuse gastric cancer with regard to its epidemiology, diagnosis, biological behavior, and factors affecting the treatment and prognosis, and discuss problems and disputes in current diagnosis and treatment, with an aim to provide convenience for the further research and help for clinical work.

Regulatory roles of grass carp EpCAM in cell morphology, proliferation and migration

Epithelial cell adhesion molecule (EpCAM) is a Ca(2+)-independent and relatively weak adhesion molecule, which has been extensively investigated in mammalian models. However, the functional roles of its fish homolog are largely unknown. In the present study, we explored the biological properties of grass carp EpCAM (gcEpCAM) in a fish kidney cell line (CIK) via overexpression of gcEpCAM or gcEpCAM intracellular domain (gcEpICD) deletion mutant. Results showed that gcEpCAM overexpression significantly changed the cell morphology, and the proliferation of the cells transfected with gcEpCAM was significantly decreased when compared to the control cells, which is unexpectedly opposite to the increasing effects induced by its mammalian homolog. Moreover, overexpression of gcEpICD deletion mutant had no effect on cell proliferation, indicating gcEpICD's involvement in the cell growth control that is concerted with its role in mammalian model. Additionally, gcEpCAM overexpression increased cell migration which is at least partially consistent with the findings in mammalian cells in which EpCAM expression both positively and negatively affects cell migration. It is worth noting that gcEpICD was not essential to the stimulatory effect of gcEpCAM on cell migration, but overexpression of human EpICD in tumor cells increases cell migration, suggesting the functional discrepancy of EpICD in fish and mammals. In conclusion, we elucidated the cellular functionality of EpCAM in fish cells which will be of benefit to defining the functions of fish EpCAM and also provide rewarding information on the functional evolution of EpCAM in vertebrates.

Expression of epithelial cellular adhesion molecule in gastric cancer: A meta-analysis

AIM: To obtain an accurate evaluation of the association between high expression of epithelial cellular adhesion molecule (EpCAM) and gastric cancer (GC) risk.

METHODS: Studies that had examined the association between high expression of EpCAM and GC risk were identified by searching electronic databases PubMed, EMBASE, Cochrane library and Chinese Biomedical Literature database. Risk ratios (RRs) together with their 95%CIs were used to assess the association between high expression of EpCAM and GC risk. We selected eligible studies based on inclusion criteria. RevMan 5.3 software was used to calculate the pooled values.

RESULTS: A total of 14 studies were included in this meta-analysis. EpCAM-positive cases were significantly associated with tumor size (RR: 1.68, 95%CI: 1.47-1.91, P < 0.00001 fixed-effect), depth of invasion (RR: 1.37, 95%CI: 1.11-1.68, P = 0.003 random-effect), TNM stage (RR: 2.02, 95%CI: 1.35-3.02, P = 0.0007 random-effect), tumor location (RR: 0.80, 95%CI: 0.71-0.91, P = 0.0007 fixed-effect), histologic differentiation (RR: 1.23, 95%CI: 1.13-1.33, P < 0.00001 fixed-effect) and lymph node metastasis (RR: 1.89, 95%CI: 1.28-2.80, P = 0.001 random-effect). However, we did not observe any significant association between the presence of EpCAM with age, gender, distant metastasis, Borrmann type or Lauren classification. Additionally, EpCAM expression was not associated with the overall survival rate. The pooled HR of the overall effect was 1.39 (95%CI: 0.30-6.48, P = 0.67 random-effect).

CONCLUSION: Our meta-analysis indicates that EpCAM contributes to GC risk, which acts as a prognostic factor and a marker of poor outcome.

Upregulated long intergenic noncoding RNA KRT18P55 acts as a novel biomarker for the progression of intestinal-type gastric cancer

Background

Long noncoding RNAs (lncRNAs) with dysregulated expression levels have been investigated in numerous types of different cancer. Whether lncRNAs can predict the progression of gastric cancer (GC) still remains largely unclear. The aim of our study was to investigate whether KRT18P55, a novel intergenic lncRNA, can be a predictive biomarker for GC.

Methods

To determine the expression levels of KRT18P55 in GC, we evaluated it in five GC cell lines (SGC-7901, MGC-803, BGC-823, AGS, and HG27) and 97 GC tissue samples in comparison with a normal control by quantitative polymerase chain reaction. In addition, the association with patient clinicopathological characteristics was analyzed to identify the clinical significance of KRT18P55. We also used publicly accessible data from The Cancer Genome Atlas (TCGA) to further verify the expression levels and clinical significance of KRT18P55. Furthermore, a receiver operating characteristic curve was also conducted to evaluate the diagnostic value of KRT18P55 for GC.

Results

A significant upregulation was observed in GC cell lines (P<0.01) and tissue samples (P<0.01). This finding was consistent with the results of 29 pairs of GC tissue samples from TCGA (P<0.01). Additionally, we indicated that the increased expression of KRT18P55 was related to the progression of intestinal type (P=0.032), which was also supported by results of independent GC cohorts from TCGA (P<0.01). However, we did not find significant difference in prognosis between patients with high and low expression of KRT18P55 (P>0.05). Finally, KRT18P55 showed potential diagnostic value for GC with an area under the receiver operating characteristic curve of 0.733 (P<0.01).

Conclusion

Upregulated KRT18P55 was a novel biomarker for the progression of GC, especially for the intestinal type.

Targeting CD44, ABCG2 and CD133 markers using aptamers: in silico analysis of CD133 extracellular domain 2 and its aptamer

Truncated CSC marker aptamers penetrate tumor spheres and inhibits cell proliferation; a bioinformatics approach to decipher their structural interactions.

Ki67--An unsuitable marker of gastric cancer prognosis unmasks intratumoral heterogeneity

Background and Objectives

Due to contradictious findings of previous studies regarding Ki67's value in gastric cancer (GC), we reevaluated the expression of Ki67 in whole tissue sections (WTS) and tissue microarrays (TMAs) of GC testing the following hypotheses: does Ki67 show intratumoral heterogeneity; are TMAs representative in the determination of the Ki67 proliferation index (PI); is the Ki67 PI subject to an intralaboratory variability; and is the Ki67 PI related to clinico‐pathological patient characteristics and/or prognostically relevant in GC.

Methods

Corresponding WTS and TMAs samples from 315 GCs were stained immunohistochemically. The Ki67 PI evaluated on WTS was correlated with the Ki67 PI evaluated on TMAs, sample age, clinico‐pathological characteristics, and patient survival.

Results

The overall amount of Ki67‐positive tumor cells did not depend on sample age. Three distinct, partly heterogeneous Ki67 expression patterns were observed. The mean Ki67 PI evaluated on TMAs differed on average minus 16.9% from the Ki67 PI evaluated on WTS. Ki67 in WTS correlated significantly with the Laurén phenotype and tumor grade, but not with patient survival.

Conclusion

TMAs carry the risk of a systematic underestimation of the Ki67 PI. Ki67 has no prognostic value in GC but might be a potential indicator of intratumoral heterogeneity. J. Surg. Oncol. 2016;113:46–54. © 2015 The Authors. Journal of Surgical Oncology published by Wiley Periodicals, Inc.

Potential therapeutic strategy for gastric cancer peritoneal metastasis by NKG2D ligands-specific T cells

Purpose

Despite advancements in its treatment, gastric cancer continues to be one of the leading causes of cancer deaths worldwide. Adoptive transfer of chimeric antigen receptor-modified T cells is a promising antitumor therapy for many cancers. The purpose of this study was to construct a chimeric receptor linking the extracellular domain of NKG2D to the CD28 and CD3zeta chain intracellular domains to target gastric cancers that expressed NKG2D ligands.

Methods

Expression of NKG2D ligands including MICA, MICB, and ULBP1–3 in a gastric cancer cell line and primary gastric cancer cells from ascites samples were analyzed using flow cytometry. Co-culture experiments were performed by incubating chNKG2D T cells with gastric cancer cell lines and with primary human gastric cancer cells isolated from ascites and by measuring cytokine and chemokine release and cytotoxicity.

Results

Gastric cancer cell lines and ascites-derived primary human gastric cancer cells expressed high levels of MICA, MICB, and ULBP2. ChNKG2D T cells secreted proinflammatory cytokines and chemokines when cultured with these cancer cells. In addition, chNKG2D T cells lysed gastric cancer cell lines and the ascites-derived primary human gastric cancer cells.

Conclusion

These data indicate that treatment with chNKG2D-expressing T cells is a potential immunotherapy for gastric cancer with peritoneal metastasis.

Comparison of the expression levels of molecular markers among the peripheral area and central area of primary tumor and metastatic lymph node tumor in patients with squamous cell carcinoma of the lung

PURPOSE

Immunohistochemical analysis for the identification of clinically relevant biomarkers is important. However, there have been no detailed reports about the heterogeneous expressions of the various markers in squamous cell carcinoma of the lung.

METHODS

A total of 113 patients with squamous cell carcinoma of the lung with lymph node metastasis were included. The expression levels of 9 molecules (E-cadherin, S100A4, CD44, ALDH1, SOX2, EGFR, HER2, FGFR1 and VEGFR2) in the peripheral area and central area of primary tumor and metastatic lymph nodes were evaluated by immunohistochemistry. The differences in the staining scores of these molecules among the three areas were assessed. We also analyzed the relationships between the expression levels of these molecules and the recurrence-free survival.

RESULTS

The E-cadherin expression was higher in the central area than in the peripheral area and metastatic lymph nodes (median staining score: 60 vs. 50, 30); the CD44 expression was higher in the central area than in the metastatic lymph nodes (117 vs. 90); and the EGFR expression was higher in the central area than in the peripheral area and metastatic lymph nodes (163 vs. 130, 110). Low CD44 expression in the central area, low EGFR expression in the peripheral area and high SOX2 expression in the metastatic lymph nodes were associated with a shorter recurrence-free survival (p < 0.01, p = 0.02, p = 0.03, respectively).

CONCLUSIONS

Our findings confirmed that some molecular markers exhibited different expression levels in anatomically different areas and suggested that area-by-area immunohistochemical analysis for biomarkers may provide useful information for more precise prediction of the recurrence.

Epithelial cell adhesion molecule is overexpressed in hypopharyngeal carcinoma and suppresses the metastasis and proliferation of the disease when downregulated

The epithelial cell adhesion molecule (EpCAM) is overexpressed in the majority of human epithelial carcinomas, and its overexpression is associated with proliferation and neoplastic transformation. However, the precise molecular mechanism involved in EpCAM-related proliferation and metastasis in hypopharyngeal carcinoma is unknown. The aim of the present study was to identify the role of EpCAM in the metastasis and proliferation of hypopharyngeal carcinoma. An immunohistochemical staining assay indicated that EpCAM was overexpressed in primary hypopharyngeal carcinoma tissues, and that this overexpression correlated with the tumor size and lymph node metastasis. In the following treatment of the hypopharyngeal carcinoma FaDu cell line with EpCAM, the downregulation of EpCAM was found to significantly suppress cell metastasis and proliferation, as detected by Transwell, clone formation and MTT assays. Additionally, western blot analysis revealed that EpCAM downregulation increased the expression of the adhesion- and proliferation-related factors, E-cadherin, α-catenin and β-catenin, in the cytoskeleton, as well as β-catenin expression in the nucleus. In conclusion, the present study indicated that EpCAM is a potential oncogene and contributes to the metastasis of hypopharyngeal carcinoma. The current study is the first to provide evidence for the potential value of targeting EpCAM in hypopharyngeal carcinoma therapy.