Strong and stable electrochemical beacons are critical for the achievement of sensitive and reliable electroanalysis applications. In this work, the electrochemical oxidation performance of AuPt NPs ...was studied and firstly found to be largely enhanced under light illumination. Plasmonic AuPt NPs collected light energy after local surface plasmon resonance (LSPR) excitation and generated much more holes to participate in the electrochemical oxidation process of Pt0 in AuPt NPs. AuPt NPs with the electrochemical oxidation peak at around −0.7 V were utilized as detection probes for the fabrication of ratiometric electrochemical aptasensor, by introducing Co-MOF/Fe3O4/Ag nanosheets (NSs) with the electrochemical oxidation peak at 0.1 V as reference beacons. The aptamers of epithelial cell adhesion molecule (EpCAM) modified AuPt NPs were assembled with Co-MOF/Fe3O4/Ag NSs, which generated strong detection and reference signals at −0.7 V and 0.1 V, respectively. The high affinity between EpCAM and aptamers induced the separation of AuPt NPs from Co-MOF/Fe3O4/Ag NSs, resulting in the decrease of detection signal at −0.7 V and unchanged reference signal at 0.1 V. A ratiometric electrochemical aptasensor was achieved for the sensitive and reliable quantification of EpCAM in the range from 100 pg/mL to 100 ng/mL. The limit of detection (LOD) was calculated to be 13.8 pg/mL for EpCAM. Plasmon-driven electrochemical oxidation enhancement principle provides the possibility for the design and fabrication of more strong and anti-interference electroactive plasmonic metal-Pt composite nanostructures for the electroanalysis applications.
•AuPt alloy NPs exhibit electro-oxidization peaks at −0.7 V.•AuPt NPs show amplified electro-oxidization activity under LSPR excitation.•The proposed plasmon-promoted electro-oxidization principle is verified.•AuPt NPs driven electrochemical aptasensor is established for EpCAM detection.
Regulated intramembrane proteolysis (RIP) has been shown to be an important mechanism for oncogenic activation of EpCAM through nuclear translocation of the intracellular domain EpICD. Recently, we ...identified two different membranous EpCAM variants namely EpCAMMF (full‐length) and EpCAMMT (truncated) to be expressed in the majority of human epithelial tumors. The aim of our study was to evaluate the potential role of these two protein variants as additional prognostic biomarkers in colorectal cancer. In most studies only one antibody targeting the extracellular domain of EpCAM (EpEX) has been used, whereas in the present study additionally an antibody which detects the intracellular domain (EpICD) was applied to discriminate between different EpCAM variants. Using immunohistochemistry, we analyzed the expression of EpCAMMF and EpCAMMT variants in 640 patients with colorectal cancer and determined their correlations with other prognostic factors and clinical outcome. A statistically significant association was observed for EpCAMMT with advanced tumor stage (p < 0.001), histological grade (p = 0.01), vascular (p < 0.001) and marginal (p = 0.002) invasion. Survival analysis demonstrated reduced overall survival (p < 0.004) in patients with tumors expressing the EpCAMMT phenotype when compared to patients with tumors expressing the EpCAMMF variant. In conclusion, this study for the first time indicates that expression of EpCAMMT is associated with a more aggressive phenotype and predicts poor survival in patients with colorectal cancer.
What's New?
Two novel cell‐adhesion molecules, the full‐length variant EpCAMMF and the truncated variant EpCAMMT, which is characterized by proteolytic cleavage of the EpCAM intracellular domain (EpICD), were recently identified on the membrane of human epithelial tumor cells. EpICD loss at the membrane is correlated with poor prognosis in pancreatic and breast cancers. Whether EpCAMMT expression, which possibly leads to EpICD loss, similarly influences tumor behavior, however, is unknown. The authors of the present study investigated the expression of EpCAMMF and EpCAMMT in colorectal cancer patients. The findings reveal an association between EpCAMMT expression, aggressive tumor behavior, and poor outcome in colorectal cancer.
Comparison of the efficacy of different enrichment methods for detection of circulating tumor cells (CTCs) before radical surgery is lacking in non‐small‐cell lung carcinoma (NSCLC) patients. ...Detection and enumeration of CTCs in 210 consecutive patients undergoing radical surgery for NSCLC were evaluated with the CellSearch Assay™ (CS), using the CellSearch Epithelial Cell Kit, and by the isolation by size of epithelial tumor (ISET) method, using double immunolabeling with anti‐cytokeratin and anti‐vimentin antibodies. CTCs were detected in 144 of 210 (69%) patients using CS and/or ISET and in 104 of 210 (50%) and 82 of 210 (39%) patients using ISET and CS, respectively. Using ISET, 23 of 210 (11%) patients had vimentin‐positive cells with cytological criteria of malignancy. Disease‐free survival (DFS) was worse for patients with CTCs compared to patients without CTCs detected by CS alone (p < 0.0001; log rank = 30.59) or by ISET alone (p < 0.0001; log rank = 33.07). The presence of CTCs detected by both CS and ISET correlated even better with shorter DFS at a univariate (p < 0.0001; log rank = 42.15) and multivariate level (HR, 1.235; 95% CI, 1.056–1.482; p < 0.001). CS and ISET are complementary methods for detection of CTCs in preoperative radical surgery for NSCLC. CTC detection in resectable NSCLC patients using CS and/or ISET could be a prognostic biomarker of great interest and may open up new avenues into improved therapeutic strategies for lung carcinoma patients.
The upregulation of epithelial cell adhesion molecule (EpCAM) expression, found in a substantial fraction of renal cell carcinomas (RCCs), renders it a potential molecular target for the treatment of ...disseminated RCC. However, the heterogeneous expression of EpCAM necessitates first identifying the patients with sufficiently high expression of EpCAM in tumors. Using the specific radionuclide-based visualization of EpCAM might enable such identification. The designed ankyrin repeat protein, Ec1, is a small (molecular weight, 18 kDa) targeting protein with a subnanomolar affinity to EpCAM. Using a modified Ec1, a tracer was developed for the radionuclide-based visualization of EpCAM in vivo, i.e., an EpCAM-visualizing designed ankyrin repeat protein (EVD). EVD was labelled with either technetium-99m using technetium tricarbonyl or with iodine-125 (as a surrogate for iodine-123) by coupling it to para-.sup.125Iiodobenzoyl (.sup.125IPIB) groups. Both the .sup.125I-labelled EVD (.sup.125I-EVD) and .sup.99mTc-labelled EVD (.sup.99mTc-EVD) bound specifically to EpCAM-expressing SK-RC-52 renal carcinoma cells. The binding affinity (K.sub.D value) of .sup.99mTc-EVD to SK-RC-52 cells was 400+ or -28 pM. The tracers' uptake in SK-RC-52 xenografts at 3 h after injection was 5.2+ or -1.4%ID/g for .sup.99m-EVD and 6.0+ or -1.4%ID/g for .sup.99mTc-EVD (no significant difference). These uptake values in SK-RC-52 xenografts were significantly higher (P<0.001) than those in Ramos lymphoma xenografts (used as EpCAM-negative control). The tumor-to-blood uptake ratio was significantly higher for .sup.99mTc-EVD (25+ or -6) compared with that of .sup.125I-EVD (14+ or -3). However, .sup.125I-EVD was associated with higher tumor-to-liver, tumor-to-salivary gland, tumor-to-spleen and tumor-to-intestinal wall ratios. This makes it the preferable tracer for visualizing EpCAM expression levels in the frequently occurring abdominal metastases of RCC. Key words: RCC, EpCAM, radionuclide molecular imaging, SPECT, .sup.125I,.sup.99mTc, DARPin Ecl, ESP
B7-H3 and EpCAM are overexpressed in cancer and play a role in tumorigenesis and metastasis. In this study, the membranous, cytoplasmic and nuclear expression levels of B7-H3 and EpCAM biomarkers ...were mapped in three major subtypes of renal cell carcinoma (RCC). Expression of B7-H3 and EpCAM were evaluated using immunohistochemistry in RCC samples on tissue microarrays (TMAs), including clear cell RCCs (ccRCCs), type I and II papillary RCCs (pRCCs), and chromophobe RCCs (chRCCs). The association between B7-H3 and EpCAM expression and clinicopathological features as well as survival outcomes was determined. There was a statistically significant difference between B7-H3 and EpCAM expression among the different RCC subtypes. In ccRCC, higher cytoplasmic expression of B7-H3 was significantly associated with increase in nucleolar grade, lymph node invasion (LNI), invasion of the Gerota's fascia, and tumor necrosis, while no association was found with the membranous and nuclear expression. Moreover tumors with cytoplasmic expression of B7-H3 tended to have a worse prognosis for disease-specific survival (DSS) than those with membranous expression. In case of EpCAM, increased membranous expression of EpCAM was associated with nucleolar grade and tumor necrosis in ccRCC. Additionally, membranous EpCAM expression added prognostic value in patients with ccRCC who had high nucleolar grade versus low nucleolar grade. Moreover, membranous EpCAM expression was found to be an independent favorable prognostic marker for progression-free survival (PFS) in ccRCC. Our results demonstrated that higher cytoplasmic B7-H3 and membranous EpCAM expression are clinically significant in ccRCC and are associated with more aggressiveness tumor behavior.
•B7-H3 and EpCAM play a role in tumorigenesis and metastasis of cancer.•The membranous, cytoplasmic and nuclear expression levels of two biomarkers have been evaluated.•Prognostic significance has also been evaluated.•Higher cytoplasmic B7-H3 and membranous EpCAM expression are clinically significant in ccRCC.•And are associated with more aggressiveness tumor behavior
Despite its limitations, the cytology of body fluids is widely used in diagnosing neoplastic cells. Flow cytometry detects and identifies individual cells, enabling the detection of circulating tumor ...cells and facilitating diagnosis. This study compared the diagnostic utility of flow cytometry and cytology for detecting cancer cells in peritoneal and pleural fluids.
We used flow cytometry and cytology to examine 119 pleural and peritoneal effusions received for routine screening. Antibodies against clusters of differentiation 45 (CD45), 14 (CD14), and Epithelial cell adhesion molecule (EpCAM) were used to detect malignant cells. Based on combined clinical and diagnostic information, 37 fluid specimens were malignant, and 77 were benign.
Flow cytometry correctly identified 34 cancers, while cytology identified 26 cancers (sensitivity 91.89 % vs. 70.27, respectively). Both methods had equal specificity (98.7 %). At a cut-off of > 0.29 % EpCAM(+) cells to all cells in the samples, flow cytometry accurately detected cancer cells, achieving 89.2 % sensitivity, 90.9 % specificity, and an AUC of 0.959 (p < 0.001).
Flow cytometry improves the detection of epithelial cancer cells in peritoneal and pleural fluids compared to conventional cytology. Due to similar specificity and higher sensitivity, flow cytometry offers a promising alternative to cytology for patient screening.
Abstract Objective Cancer cells in the body release soluble and membranous factors that manipulate the tumor environment to facilitate growth and survival. Recent years have provided evidence that ...small microvesicles that are termed exosomes may play a pivotal role in this process. Exosomes are membrane vesicles with a size of 40–100 nm that are released by both tumor and normal cells and can be found in various body fluids. Tumor-derived exosomes carry functional proteins, mRNAs, and miRNAs and could serve as novel platform for tumor diagnosis and prognosis. However, marker proteins that allow enrichment of tumor-derived exosomes over normal exosomes are less well defined. Methods We used Western blot analysis and antibody coupled magnetic beads to characterize CD24 and EpCAM as markers for exosomes. We investigated ovarian carcinoma ascites, pleural effusions and serum of breast carcinoma patients. As non-tumor derived control we used exosomes from ascites of liver cirrhosis patients. Results Exosomes could be isolated from all body fluids and contained marker proteins as well as miRNAs. We observed that CD24 and EpCAM were selectively present on ascites exosomes of tumor patients and copurified together on anti-EpCAM or anti-CD24 magnetic beads. In breast cancer patients CD24 was present but EpCAM was absent from serum exosomes. Instead, the intact EpCAM ectodomain was recovered in a soluble form. We provide evidence that EpCAM can be cleaved from exosomes via serum metalloproteinase(s). Conclusion Loss of EpCAM on serum exosomes may hamper enrichment by immune-affinity isolation. We suggest that CD24 could be an additional marker for the enrichment of tumor-derived exosomes from blood.
Targeted delivery of anticancer agents by functional nanoparticles is an attractive strategy to increase their therapeutic efficacy while reducing toxicity. In this work, doxorubicin (DOX)-loaded ...mesoporous silica nanoparticles (MSNs) were modified with aptamer (Ap) against the epithelial cell adhesion molecule (EpCAM) for targeted delivery of DOX to colon cancer cells. These nanoparticles (Ap-MSN-DOX) were characterized by particle size, zeta potential, aptamer conjugation efficiency, drug encapsulation efficiency, and drug release properties. The in vitro cell recognition, cellular uptake, EpCAM protein inhibition efficiency, and cytotoxicity of Ap-MSN-DOX were also studied. Results demonstrated that EpCAM conjugation increased binding of Ap-MSN-DOX to EpCAM over-expressing SW620 colon cancer cells but not EpCAM-negative Ramos cells, resulting in enhanced cellular uptake and increased cytotoxicity of the DOX in SW620 cells when compared to non-Ap-modified nanoparticles (MSN-DOX). Additionally, Ap-MSN-DOX exhibited significant inhibition effects on the expression of EpCAM on SW620 cells. These results suggested that Ap-MSN-DOX has the potential for the targeted delivery of therapeutic agents into EpCAM positive colon cancer cells to improve therapeutic index while reducing side effects.
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Magnetic mesoporous silica nanoparticles (M-MSNs) are attractive candidates for the immunomagnetic isolation and detection of circulating tumor cells (CTCs). Understanding of the interactions between ...the effects of the shape of M-MSNs and CTCs is crucial to maximize the binding capacity and capture efficiency as well as to facilitate the sensitivity and efficiency of detection. In this work, fluorescent M-MSNs were rationally designed with sphere and rod morphologies while retaining their robust fluorescence and uniform surface functionality. After conjugation with the antibody of epithelial cell adhesion molecule (EpCAM), both of the differently shaped M-MSNs-EpCAM obtained achieved efficient enrichment of CTCs and fluorescent-based detection. Importantly, rodlike M-MSNs exhibited faster immunomagnetic isolation as well as better performance in the isolation and detection of CTCs in spiked cells and real clinical blood samples than those of their spherelike counterparts. Our results showed that shape engineering contributes positively toward immunomagnetic isolation, which might open new avenues to the rational design of magnetic-fluorescent nanoprobes for the sensitive and efficient isolation and detection of CTCs.
Colon cancer (CC) is one of the leading causes of cancer related mortality. Research over past decades have profoundly enhanced our understanding of immunotherapy, a major clinical accomplishment, ...and its potential role toward treating CC. However, studies investigating the expression of these immune checkpoints, such as epithelial cell adhesion molecule (EpCAM), programmed death-1 (PD-1), and programmed death-ligand 1 (PD-L1), by peripheral blood mononuclear cells (PBMCs) is lacking. Here, high-dimensional mass cytometry (CyTOF) is used to investigate immune alterations and promising immunotherapeutic targets expression by PBMCs of CC patients. Results reveal that expression of EpCAM and PD-L1 on CD4
T cells significantly increased in patients with CC, compared with age- and sex- matching healthy controls and patients with colonic polyps. These differences are also validated in an independent patient cohort using flow cytometry. Further analysis revealed that EpCAM
CD4
T cells are PD-L1
CCR5
CCR6
. Immunofluorescence staining results demonstrate that the increase of EpCAM
CD4
T cells is also observed in tumor tissues, rather than para-cancerous tissues. To ascertain the functional disorders of the identified cell subset, phosphorylated signaling protein levels are assessed using imaging mass cytometry. Increases in pp38 MAPK and pMAPKAPK2 are observable, indicating abnormal activation of pp38 MAPK-pMAPKAPK2 signaling pathway. Results in this study indicate that EpCAM
CD4
T cells may play a role in CC development. Detailed knowledge on the functionality of EpCAM
CD4
T cells is of high translational relevance.
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