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

Detection and isolation of viable cancer cells mediated by spytag and spycatcher using conditionally replicative adenovirus and magnetic microbeads

Circulating tumor cells (CTCs) are critical biomarkers for cancer diagnosis, prognosis, and therapy monitoring, but their rarity and reliance on surface markers limit detection and isolation. While conditionally replicative adenoviruses (crADs) enable tumor-selective targeting, their use has been limited to fluorescence-based detection without robust isolation of viable cells. To overcome this, we developed a crAD-based platform integrating SpyTag/SpyCatcher technology with SpyCatcher-decorated magnetic microbeads for marker-independent CTC detection and isolation. The engineered adenovirus (CR-Ad5-ST-GFP) selectively replicates in telomerase-positive tumor cells, expressing green fluorescent protein (GFP) and SpyTag under independent promoters. By leveraging the SpyTag/SpyCatcher interaction, our platform isolates CTCs without relying on surface markers, addressing epithelial-to-mesenchymal transition (EMT) and phenotype variations. In proof-of-concept experiments, A-549 and Ca Ski cells spiked into peripheral blood mononuclear cells (PBMCs) at 1:10,000 were detected and isolated with over 80% efficiency. The isolated cells remained viable and were successfully re-cultured, demonstrating their potential for downstream applications such as molecular profiling and drug sensitivity testing. This method advances crAD-based approaches by combining tumor-selective viral targeting with marker-independent, viable CTC isolation. Its compatibility with microfluidic systems makes it a promising tool for tumor monitoring and personalized cancer treatment.

Gravitational forces and matrix stiffness modulate the invasiveness of breast cancer cells in bioprinted spheroids

The progression of breast cancer is influenced by the stiffness of the extracellular matrix (ECM), which becomes stiffer as cancer advances due to increased collagen IV and laminin secretion by cancer-associated fibroblasts. Intriguingly, breast cancer cells cultivated in two-dimensions exhibit a less aggressive behavior when exposed to weightlessness, or microgravity conditions. This study aims to elucidate the interplay between matrix stiffness and microgravity on breast cancer progression. For this purpose, three-dimensional spheroids of breast cancer cell lines (MCF-7 and MDA-MB-231) were formed. These spheroids were subsequently bioprinted in hydrogels of varying stiffness, obtained by the mixing of gelatin methacrylate and poly(ethylene) glycol diacrylate mixed at different ratios. The constructs were printed with a custom stereolithography (SLA) bioprinter converted from a low-cost, commercially available 3D printer. These bioprinted structures, encapsulating breast cancer spheroids, were then placed in a clinostat (microgravity simulation device) for a duration of seven days. Comparative analyses were conducted between objects cultured under microgravity and standard earth gravity conditions. Protein expression was characterized through fluorescent microscopy, while gene expression of MCF-7 constructs was analyzed via RNA sequencing. Remarkably, the influence of a stiffer ECM on the protein and gene expression levels of breast cancer cells could be modulated and sometimes even reversed in microgravity conditions. The study's findings hold implications for refining therapeutic strategies for advanced breast cancer stages - an array of genes involved in reversing aggressive or even metastatic behavior might lead to the discovery of new compounds that could be used in a clinical setting.

Multifaceted Approaches in Epithelial Cell Adhesion Molecule-Mediated Circulating Tumor Cell Isolation

Circulating tumor cells (CTCs) are pivotal in cancer metastasis and serve as valuable biomarkers for diagnosis, prognosis, and treatment monitoring. Traditional CTC capture methods predominantly utilize the epithelial cell adhesion molecule (EpCAM) as a marker for isolation. However, the heterogeneity of these circulating cells and the epithelial-to-mesenchymal transition process (wherein epithelial cells acquire mesenchymal characteristics) limit the efficacy of EpCAM-based capture techniques. In this paper, we critically review the role of the EpCAM in CTC capture, explore the impact of epithelial-to-mesenchymal transition on EpCAM expression, and discuss alternative biomarkers and strategies to enhance CTC isolation. By evaluating the limitations of EpCAM-mediated capture and the challenges posed by epithelial-to-mesenchymal transition, we aim to provide insights into the development of more comprehensive liquid biopsy approaches for cancer management.

Biomaterial-based 3D human lung models replicate pathological characteristics of early pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive and incurable lung disease characterized by tissue scarring that disrupts gas exchange. Epithelial cell dysfunction, fibroblast activation, and excessive extracellular matrix deposition drive this pathology that ultimately leads to respiratory failure. Mechanistic studies have shown that repeated injury to alveolar epithelial cells initiates an aberrant wound-healing response in surrounding fibroblasts through secretion of mediators like transforming growth factor-β, yet the precise biological pathways contributing to disease progression are not fully understood. To better study these interactions there is a critical need for lung models that replicate the cellular heterogeneity, geometry, and biomechanics of the distal lung microenvironment. In this study, induced pluripotent stem cell-derived alveolar epithelial type II (iATII) cells and human pulmonary fibroblasts were arranged to replicate human lung micro-architecture and embedded in soft or stiff poly(ethylene glycol) norbornene (PEG-NB) hydrogels that recapitulated the mechanical properties of healthy and fibrotic lung tissue, respectively. The co-cultured cells were then exposed to pro-fibrotic biochemical cues, including inflammatory cytokines and growth factors. iATIIs and fibroblasts exhibited differentiation pathways and gene expression patterns consistent with trends observed during IPF progression in vivo. A design of experiments statistical analysis identified stiff hydrogels combined with pro-fibrotic biochemical cue exposure as the most effective condition for modeling fibrosis in vitro. Finally, treatment with Nintedanib, one of only two Food and Drug Administration (FDA)-approved drugs for IPF, was assessed. Treatment reduced fibroblast activation, as indicated by downregulation of key activation genes, and upregulated several epithelial genes. These findings demonstrate that human 3D co-culture models hold tremendous potential for advancing our understanding of IPF and identifying novel therapeutic targets.

EpCAM Signaling in Oral Cancer Stem Cells: Implications for Metastasis, Tumorigenicity, and Therapeutic Strategies

Oral cancer, a subtype of head and neck cancer, poses significant global health challenges owing to its late diagnosis and high metastatic potential. The epithelial cell adhesion molecule (EpCAM), a transmembrane glycoprotein, has emerged as a critical player in cancer biology, particularly in oral cancer stem cells (CSCs). This review highlights the multifaceted roles of EPCAM in regulating oral cancer metastasis, tumorigenicity, and resistance to therapy. EpCAM influences key pathways, including Wnt/β-catenin and EGFR, modulating CSC self-renewal, epithelial-to-mesenchymal transition (EMT), and immune evasion. Moreover, EpCAM has been implicated in metabolic reprogramming, epigenetic regulation, and crosstalk with other signaling pathways. Advances in EpCAM-targeting strategies, such as monoclonal antibodies, chimeric antigen receptor (CAR) T/NK cell therapies, and aptamer-based systems hold promise for personalized cancer therapies. However, challenges remain in understanding the precise mechanism of EpCAM in CSC biology and its translation into clinical applications. This review highlights the need for further investigation into the role of EPCAM in oral CSCs and its potential as a therapeutic target to improve patient outcomes.

Novel human single-domain antibodies exert potent anti-tumor activity by targeting EGF-like repeat epitope of EpCAM

Introduction

EpCAM (Epithelial cell adhesion molecule) is a key cancer stem cell marker involved in cancer progression, making it an important target for both diagnosis and therapy. Despite efforts using anti-EpCAM monoclonal antibodies (mAbs), their anti-tumor effects have been limited. Single-domain antibodies (sdAbs), in contrast, offer advantages such as efficient tumor penetration and reduced immunogenicity. This study aims to screen and explore novel sdAbs targeting EpCAM for cancer therapy.

Methods

A critical EGF-like repeat epitope on the EpCAM extracellular domain was selected for screening a human sdAb library via phage display. The selected sdAbs were purified and their anti-cancer activity was validated through specific binding with the EpCAM peptide. The effects of these sdAbs on cell proliferation, migration, invasion, and apoptosis were tested in vitro, and their anti-tumor activity was assessed in a xenograft model.

Results

Five fully human anti-EpCAM sdAbs were isolated, all of which specifically bound to the EpCAM peptide and showed selective binding to various cancer cell lines, but not to 293T and 3T3 cells. Functional assays demonstrated that these sdAbs significantly inhibited cancer cell proliferation, migration, and invasion, and induced apoptosis. Notably, two sdAbs (aEP3D4 and aEP4G2) exhibited potent anti-tumor effects in vivo, significantly reducing tumor volume and weight in a mouse xenograft model.

Discussion

This study provides compelling evidence that targeting EpCAM with sdAbs is a promising approach for cancer treatment. The identified anti-EpCAM sdAbs exhibit substantial anti-tumor activity both in vitro and in vivo, suggesting they are strong candidates for future therapeutic applications in cancer therapy.

Lipidomic profiling of triple-negative breast cancer cells reveals distinct metabolic signatures associated with EpCAM expression

Lipid metabolism is essential at all stages of cancer progression, particularly for triple-negative breast cancer (TNBC) the deadliest cancer subtype for women patients. TNBC cells exhibit significant metabolic heterogeneity, which contributes to their aggressive behavior. Epithelial-to-mesenchymal transition (EMT), a key step in metastasis, is associated with distinct lipid profiles, where the epithelial cell adhesion molecule (EpCAM) was found to be decreased along the transition. To understand this link, we employed lipidomic profiling of the TNBC cell line SUM149PT, which exhibits high variability in EpCAM, an epithelial marker. Using EpCAM levels to categorize cells with high and low EpCAM expression using fluorescence-activated cell sorter, we performed targeted mass spectrometry analysis of various lipid classes (glycerophospholipids, glycerolipids, lysophospholipids, and sphingolipids) by a hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS)-based screening method. After correcting for cell size, we identified a unique lipid profile associated with each EpCAM expression level. Notably, cells with higher EpCAM expression displayed lower levels of lysophosphatidylethanolamine (LPE). This finding suggests a potential role for LPE in the regulation of EMT in TNBC.

A comprehensive review and meta-analysis of CTC isolation methods in breast cancer

The application of circulating tumor cells (CTCs) as diagnostic and prognostic markers in oncology is gaining increasing importance in clinical practice. Currently, various methods exist for detecting CTCs in patients' biological fluids. This systematic review aimed to compare the efficacy of different techniques for isolating and detecting CTCs from blood, against the FDA-cleared CellSearch® technology, in breast cancer patients. We performed a systematic literature search using two databases (PubMed and the Cochrane Library) with the following terms: ("Circulating tumor cells" OR CTC) AND "breast cancer", covering the period from 2004 to April 2023. The primary outcome measured was the sensitivity, specificity, and overall accuracy of various CTC enrichment methods in comparison with the CellSearch® System. Secondary outcomes included the prognostic value of CTCs in evaluating response to treatment based on survival rates. Generally, a high level of agreement between CellSearch and other methods was observed in isolating CTCs from patients' blood with both metastatic and early-stage disease. Studies asserting the superiority of new methods over CellSearch frequently used clinically unvalidated cut-off thresholds for their patient cohorts. Additionally, these studies sometimes included different nonoverlapping patient cohorts and lacked a standardized chemotherapy treatment protocol, which could affect the quantitative changes in CTC. It is evident that methods simultaneously composed of physical and immunomagnetic approaches for CTC isolation significantly surpass CellSearch, which relies solely on the expression of specific markers on the CTCs' surface. The count of CTCs has been established as a predictive marker in terms of clinically important parameters namely progression-free survival (PFS) and overall survival (OS). The CTC-count value was significantly correlated with PFS and OS rates.

Promising therapeutic targets for tumor treatment: Cleaved activation of receptors in the nucleus

A new fate of cell surface receptors, cleaved activation in the nucleus, is summarized. The intracellular domain (ICD) of cell surface receptors, cleaved by enzymes like γ-secretase, translocates to the nucleus to form transcriptional complexes participating in the onset and development of tumors. The fate is clinically significant, as inhibitors of cleavage enzymes have shown effectiveness in treating advanced tumors by reducing tumorigenic ICDs. Additionally, the construction of synthetic receptors also conforms with the fate mechanism. This review details each step of cleaved activation in the nucleus, elucidates tumorigenic mechanisms, explores application in antitumor therapy, and scrutinizes possible limitations.

In Silico Design of Novel EpCAM-Binding Aptamers for Targeted Delivery of RNA Therapeutics

Aptamers are short DNA or RNA sequences that adopt 3D structures and can bind to protein targets with high binding affinity and specificity. Aptamers exhibit excellent tissue penetration, are inexpensive to produce, and can be internalized by cells. Therefore, aptamers are attractive targeting ligands to direct the delivery of theranostic agents to the desired cells. Epithelial cell adhesion molecule (EpCAM) is a tumor-associated antigen that is aberrantly overexpressed on many epithelial-derived cancers, including on cholangiocarcinoma (CCA) cells. Its expression on treatment-resistant cancer stem cells, along with its abundance in the CCA tumor microenvironment, highlights the need to develop EpCAM-targeted therapies for CCA. Herein, an in silico approach was used to design and screen DNA aptamers capable of binding to the EpCAM monomer and homodimer. Two aptamers, PLD01 and PLD02, met the selection criteria and were validated in vitro. Both aptamers exhibited high affinity for EpCAM+ CCA cells, with negligible binding to EpCAM- leukemia cells. Modified versions of PLD01 and PLD02 were successfully incorporated into the membranes of milk-derived nanovesicles. PLD01-functionalized nanovesicles enabled EpCAM-targeted delivery of the therapeutic cargo to CCA cells. In summary, these EpCAM-targeting aptamers can be utilized to direct the delivery of theranostic agents to EpCAM-expressing cells.

Characterization of EpCAM-Positive and EpCAM-Negative Tumor Cells in Early-Stage Breast Cancer

Most studies on CTCs have focused on isolating cells that express EpCAM. In this study, we emphasize the presence of EpCAM-negative and EpCAMlow CTCs, in addition to EpCAMhigh CTCs, in early BC. We evaluated stem cell markers (CD44/CD24 and CD133) and EMT markers (N-cadherin) in each subpopulation. Our findings indicate that all stemness variants were present in both EpCAMhigh and EpCAM-negative CTCs, whereas only one variant of stemness (nonCD44+CD24-/CD133+) was observed among EpCAMlow CTCs. Nearly all EpCAMhigh CTCs were represented by CD133+ stem cells. Notably, the hybrid EMT phenotype was more prevalent among EpCAM-negative CTCs. scRNA-seq of isolated CTCs and primary tumor partially confirmed this pattern. Therefore, further investigation is imperative to elucidate the prognostic significance of EpCAM-negative and EpCAMlow CTCs.

Intracellular domain of epithelial cell adhesion molecule induces Wnt receptor transcription to promote colorectal cancer progression

BACKGROUND

Epithelial cell adhesion molecule (EpCAM) has been widely studied as a tumor antigen due to its expression in varieties of solid tumors. Moreover, the glycoprotein contributes to critical cancer-associated cellular functionalities via its extracellular (EpEX) and intracellular (EpICD) domains. In colorectal cancer (CRC), EpCAM has been implicated in the Wnt signaling pathway, as EpICD and β-Catenin are coordinately translocated to the nucleus. Once in the nucleus, EpICD transcriptionally regulates EpCAM target genes that; however, remains unclear whether Wnt signaling is modulated by EpICD activity.

METHODS

Patient-derived organoids (PDOs), patient-derived xenografts (PDXs), and various CRC cell lines were used to study the roles of EpCAM and EpICD in Wnt receptor expression. Fluorescence and confocal microscopy were used to analyze tumors isolated from PDX and other xenograft models as well as CRC cell lines. EpCAM signaling was intervened with our humanized form of EpCAM neutralizing antibody, hEpAb2-6. Wnt receptor promoters under luciferase reporters were constructed to examine the effects of EpICD. Luciferase reporter assays were performed to evaluate promoter, γ-secretase and Wnt activity. Functional assays including in vivo tumor formation, organoid formation, spheroid and colony formation experiments were performed to study Wnt related phenomena. The therapeutic potential of EpCAM suppression by hEpAb2-6 was evaluated in xenograft and orthotopic models of human CRC.

RESULTS

EpICD interacted with the promoters of Wnt receptors (FZD6 and LRP5/6) thus upregulated their transcriptional activity inducing Wnt signaling. Furthermore, activation of Wnt-pathway-associated kinases in the β-Catenin destruction complex (GSK3β and CK1) induced γ-secretase activity to augment EpICD shedding, establishing a positive-feedback loop. Our hEpAb2-6 antibody blocked EpICD-mediated upregulation of Wnt receptor expressions and conferred therapeutic benefits in both PDX and orthotopic models of human CRC.

CONCLUSIONS

This study uncovers relevant functions of EpCAM where Wnt receptors are upregulated via the transcriptional co-factor activity of EpICD. The resultant enhancement of Wnt signaling induces γ-secretase activity further stimulating EpICD cleavage and its nuclear translocation. Our humanized anti-EpCAM antibody hEpAb2-6 blocks these mechanisms and may thereby provide therapeutic benefit in CRC.

Three-Dimensional DNA Hydrogel Mediated Dual-Mode Sensing Method for Quantification of Epithelial Cell Adhesion Molecule in Biological Fluid Samples

Monitoring changes in the expression of marker proteins in biological fluids is essential for biomarker-based disease diagnosis. Epithelial cell adhesion molecule (EpCAM) has been identified as a broad-spectrum biomarker for various chronic diseases and as a therapeutic target. However, the development of simple and reliable methods for quantifying EpCAM changes in biological fluids faces challenges due to the variability of its expression across different diseases, the presence of soluble forms, and matrix effects. In this paper, a surface-enhanced Raman scattering (SERS)-fluorescence (FL) dual-mode sensing method was established for quantification of trace EpCAM in biological fluids based on bimetallic Au@Ag nanoparticles and nitrogen-doped quantum dots encapsulated DNA hydrogel hybrid with graphene oxide (Au@Ag-NQDs/GO). The DNA hydrogel was constructed based on three-dimensional (3D) structure DNA-mediated strategy using an aptamer DNA (AptDNA) linker. The interaction of the AptDNA with EpCAM triggered the disassembly of the DNA hydrogel. Consequently, the release of Au@Ag nanoparticles induced an "on-off" switch in the SERS signal while the weakened FL quenching effect in Au@Ag-NQDs/GO system achieved "off-on" switch of FL signal, enabling the simultaneous SERS-FL quantification of EpCAM. The established dual-mode method exhibited outstanding sensitivity and stability in quantifying EpCAM in the range of 0.5-60.0 pg/mL, with the limits of detection (LODs) of SERS and FL as 0.17 and 0.35 pg/mL, respectively. When applied for real sample analysis, the method showed satisfactory specificity and recoveries in cancer cells lysate, serum, and urine samples with RSDs of 2.8-6.3%, 4.0-6.3%, and 2.8-5.7%, respectively. The developed SERS-FL sensing method offered a sensitive, reliable, and practical quantification strategy for trace EpCAM in diverse biological fluid samples, which would benefit the early diagnosis of disease and further health management.

Identification of tumor stemness and immunity related prognostic factors and sensitive drugs in head and neck squamous cell carcinoma

The presence of cancer stem cells (CSCs) contributes significantly to treatment resistance in various cancers, including head and neck squamous cell carcinoma (HNSCC). Despite this, the relationship between cancer stemness and immunity remains poorly understood. In this study, we aimed to identify potential immunotherapeutic targets and sensitive drugs for CSCs in HNSCC. Using data from public databases, we analyzed expression patterns and prognostic values in HNSCC. The stemness index was calculated using the single-sample gene set enrichment analysis (ssgsea) algorithm, and weighted gene co-expression network analysis (WGCNA) was employed to screen for key stemness-related modules. Consensus clustering was then used to group samples for further analysis, and prognosis-related key genes were identified through regression analysis. Our results showed that tumor samples from HNSCC exhibited higher stemness indices compared to normal samples. WGCNA identified a module highly correlated with stemness, comprising 187 genes, which were significantly enriched in protein digestion and absorption pathways. Furthermore, we identified sensitive drugs targeting prognostic genes associated with tumor stemness. Notably, two genes, HLF and CCL11, were found to be highly associated with both stemness and immunity. In conclusion, our study identifies a stemness-related gene signature and promising drug candidates for CSCs of HNSCC. Additionally, HLF and CCL11, which are associated with both stemness and immunity, represent potential targets for immunotherapy in HNSCC.

Long-Term In Vitro Culture Alters Gene Expression Pattern of Genes Involved in Ontological Groups Representing Cellular Processes

The oviduct provides an optimal environment for the final preparation, transport, and survival of gametes, the fertilization process, and early embryonic development. Most of the studies on reproduction are based on in vitro cell culture models because of the cell's accessibility. It creates opportunities to explore the complexity of directly linked processes between cells. Previous studies showed a significant expression of genes responsible for cell differentiation, maturation, and development during long-term porcine oviduct epithelial cells (POECs) in vitro culture. This study aimed at establishing the transcriptomic profile and comprehensive characteristics of porcine oviduct epithelial cell in vitro cultures, to compare changes in gene expression over time and deliver information about the expression pattern of genes highlighted in specific GO groups. The oviduct cells were collected after 7, 15, and 30 days of in vitro cultivation. The transcriptomic profile of gene expression was compared to the control group (cells collected after the first day). The expression of COL1A2 and LOX was enhanced, while FGFBP1, SERPINB2, and OVGP1 were downregulated at all selected intervals of cell culture in comparison to the 24-h control (p-value < 0.05). Adding new detailed information to the reproductive biology field about the diversified transcriptome profile in POECs may create new future possibilities in infertility treatments, including assisted reproductive technique (ART) programmes, and may be a valuable tool to investigate the potential role of oviduct cells in post-ovulation events.

Chlorogenic Acid and Cinnamaldehyde in Combination Inhibit Metastatic Traits and Induce Apoptosis via Akt Downregulation in Breast Cancer Cells

Most reported breast cancer-associated deaths are directly correlated with metastatic disease. Additionally, the primary goal of treating metastatic breast cancer is to prolong life. Thus, there remains the need for more effective and safer strategies to treat metastatic breast cancer. Recently, more attention has been given to natural products (or phytochemicals) as potential anticancer treatments. This study aimed to investigate the synergistic effects of the combination of the phytochemicals chlorogenic acid and cinnamaldehyde (CGA and CA) toward inhibiting metastasis. The hypothesis was that CGA and CA in combination decrease the metastatic potential of breast cancer cells by inhibiting their invasive and migratory abilities as well as the induction of apoptosis via the downregulation of the Akt, disrupting its signal transduction pathway. To test this, wound-healing and Transwell™ Matrigel™ assays were conducted to assess changes in the migration and invasion properties of the cells; apoptosis was analyzed by fluorescence microscopy for Annexin V/propidium iodide; and immunoblotting and FACSort were performed on markers for the epithelial-to-mesenchymal transition status. The results show that CGA and CA significantly downregulated Akt activation by inhibiting phosphorylation. Consequently, increased caspase 3 and decreased Bcl2-α levels were observed, and apoptosis was confirmed. The inhibition of metastatic behavior was demonstrated by the attenuation of N-cadherin, fibronectin, vimentin, and MMP-9 expressions with concomitant increased expressions of E-cadherin and EpCAM. In summary, the present study demonstrated that CGA and CA in combination downregulated Akt activation, inhibited the metastatic potential, and induced apoptosis in different breast cancer cell lines.

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.

Curcumin-loaded liposomes modulating the synergistic role of EpCAM and estrogen receptor alpha in lung cancer management

Lung cancer (LC) remains a leading cause of cancer-related mortality worldwide, necessitating the exploration of innovative therapeutic strategies. This study delves into the in vitro potential of liposomal therapeutics utilizing Curcumin-loaded PlexoZome® (CUR-PLXZ) in targeting EpCAM/TROP1 and Estrogen Receptor Alpha (ERα) signalling pathways for LC management. The prevalence of LC, particularly non-small cell lung cancer (NSCLC), underscores the urgent need for effective treatments. Biomarkers like EpCAM/TROP1 and ERα/NR3A1 play crucial roles in guiding targeted therapies and influencing prognosis. EpCAM plays a key role in cell-cell adhesion and signalling along with ERα which is a nuclear receptor that binds estrogen and regulates gene expression in response to hormonal signals. In LC, both often get overexpressed and are associated with tumour progression, metastasis, and poor prognosis. Curcumin, a phytochemical with diverse therapeutic properties, holds promise in targeting these pathways. However, its limited solubility and bioavailability necessitate advanced formulations like CUR-PLXZ. Our study investigates the biological significance of these biomarkers in the A549 cell line and explores the therapeutic potential of CUR-PLXZ, which modulates the expression of these two markers. An in vitro analysis of the A549 human lung adenocarcinoma cell line identified that CUR-PLXZ at a dose of 5 μM effectively inhibited the expression of EpCAM and ERα. This finding paves the way for targeted intervention strategies in LC management.

Liquid biopsy for gastric cancer: Techniques, applications, and future directions

After the study of circulating tumor cells in blood through liquid biopsy (LB), this technique has evolved to encompass the analysis of multiple materials originating from the tumor, such as nucleic acids, extracellular vesicles, tumor-educated platelets, and other metabolites. Additionally, research has extended to include the examination of samples other than blood or plasma, such as saliva, gastric juice, urine, or stool. LB techniques are diverse, intricate, and variable. They must be highly sensitive, and pre-analytical, patient, and tumor-related factors significantly influence the detection threshold, diagnostic method selection, and potential results. Consequently, the implementation of LB in clinical practice still faces several challenges. The potential applications of LB range from early cancer detection to guiding targeted therapy or immunotherapy in both early and advanced cancer cases, monitoring treatment response, early identification of relapses, or assessing patient risk. On the other hand, gastric cancer (GC) is a disease often diagnosed at advanced stages. Despite recent advances in molecular understanding, the currently available treatment options have not substantially improved the prognosis for many of these patients. The application of LB in GC could be highly valuable as a non-invasive method for early diagnosis and for enhancing the management and outcomes of these patients. In this comprehensive review, from a pathologist's perspective, we provide an overview of the main options available in LB, delve into the fundamental principles of the most studied techniques, explore the potential utility of LB application in the context of GC, and address the obstacles that need to be overcome in the future to make this innovative technique a game-changer in cancer diagnosis and treatment within clinical practice.

Glucocorticoid receptor: a harmonizer of cellular plasticity in breast cancer-directs the road towards therapy resistance, metastatic progression and recurrence

Recent therapeutic advances have significantly uplifted the quality of life in breast cancer patients, yet several impediments block the road to disease-free survival. This involves unresponsiveness towards administered therapy, epithelial to mesenchymal transition, and metastatic progression with the eventual appearance of recurrent disease. Attainment of such characteristics is a huge adaptive challenge to which tumour cells respond by acquiring diverse phenotypically plastic states. Several signalling networks and mediators are involved in such a process. Glucocorticoid receptor being a mediator of stress response imparts prognostic significance in the context of breast carcinoma. Involvement of the glucocorticoid receptor in the signalling cascade of breast cancer phenotypic plasticity needs further elucidation. This review attempted to shed light on the inter-regulatory interactions of the glucocorticoid receptor with the mediators of the plasticity program in breast cancer; which may provide a hint for strategizing therapeutics against the glucocorticoid/glucocorticoid receptor axis so as to modulate phenotypic plasticity in breast carcinoma.

Molecular characteristics of isthmus papillary thyroid cancers: Supporting evidence for unfavorable clinical behavior

BACKGROUND

Previous studies demonstrate isthmus thyroid nodules are more likely to be malignant than lobar nodules. Additional data suggest that isthmus papillary thyroid cancers (PTCs) are more aggressive than lobar PTCs. We hypothesize that isthmus PTCs have a more unfavorable molecular profile.

METHODS

The Cancer Genome Atlas (TCGA) database was queried to analyze clinical, mutation and gene expression data of isthmus PTCs compared to non-isthmus PTCs.

RESULTS

We analyzed characteristics of 472 ​PTCs, including 19 isthmus PTCs. There were no significant differences between isthmus and non-isthmus PTC demographic and clinical variables or the frequency of RAS family, fusion driver, TERT, and tumor suppressor gene mutations. There was a trend towards increased BRAF mutations (68% vs 55%, p ​= ​0.28). A more aggressive gene expression profile was observed in isthmus PTC compared to lobar/multifocal PTC with differences in ERK score (19.4 vs 7.71, p ​< ​0.05) and TDS score (-0.58 vs 0.02, p ​< ​0.05).

CONCLUSIONS

These results provide a possible molecular explanation for the more aggressive behavior reported in isthmus PTCs.

A perspective on emerging therapies in metastatic colorectal cancer: Focusing on molecular medicine and drug resistance

The majority of cancer cases are colorectal cancer, which is also the second largest cause of cancer-related deaths worldwide. Metastasis is the leading cause of death for patients with colorectal cancer. Metastatic colorectal cancer incidence are on the rise due to a tiny percentage of tumors developing resistant to medicines despite advances in treatment tactics. Cutting-edge targeted medications are now the go-to option for customized and all-encompassing CRC care. Specifically, multitarget kinase inhibitors, antivascular endothelial growth factors, and epidermal growth factor receptors are widely used in clinical practice for CRC-targeted treatments. Rare targets in metastatic colorectal cancer are becoming more well-known due to developments in precision diagnostics and the extensive use of second-generation sequencing technology. These targets include the KRAS mutation, the BRAF V600E mutation, the HER2 overexpression/amplification, and the MSI-H/dMMR. Incorporating certain medications into clinical trials has significantly increased patient survival rates, opening new avenues and bringing fresh viewpoints for treating metastatic colorectal cancer. These focused therapies change how cancer is treated, giving patients new hope and better results. These markers can significantly transform and individualize therapy regimens. They could open the door to precisely customized and more effective medicines, improving patient outcomes and quality of life. The fast-growing body of knowledge regarding the molecular biology of colorectal cancer and the latest developments in gene sequencing and molecular diagnostics are directly responsible for this advancement.

Salmonella inhibits tumor metastasis by downregulating epithelial cell adhesion molecules through the protein kinase-B/mammalian target of rapamycin signaling pathway

Epithelial cell adhesion molecules (EpCAM) are highly expressed in many carcinomas and regulate the epithelial-mesenchymal transition, which is required for tumor metastasis. Furthermore, EpCAM overexpression induces tumor cells to develop a stem cell-like phenotype and promotes tumor progression. Targeting EpCAM may be a promising approach for inhibiting tumor metastasis and progression. Salmonella treatment suppresses tumor growth and reduces metastatic nodules in tumor-bearing mice. Based on these results, we hypothesized that Salmonella-based treatments could inhibit the expression of metastasis-associated proteins. The dose-dependent Salmonella treatment significantly downregulated the levels of EpCAM and decreased the phosphorylation of protein kinase-B (AKT)/mTOR (mammalian target of rapamycin) pathway, as shown by immunoblotting. In addition, Salmonella treatment increased the levels of epithelial markers and decreased the levels of mesenchymal markers in a dose-dependent manner. Wound-healing and Transwell assays showed that Salmonella treatment significantly reduced tumor cell migration. The mice were intravenously injected with B16F10 and CT26 cells pre-incubated with or without Salmonella, and the survival of tumor-bearing mice in the Salmonella group increased, indicating an antimetastatic effect. Our findings demonstrate that Salmonella plays a role in inhibiting tumor metastasis by downregulating EpCAM via the AKT/mTOR signaling pathway and has great potential for cancer therapy.

R. H, Liu J, B. M. N, Zhao D, Vishwanath P, B. M. G, Fan R. Screening fructosamine-3-kinase (FN3K) inhibitors, a deglycating enzyme of oncogenic Nrf2: Human FN3K homology modelling, docking and molecular dynamics simulations

Fructosamine-3-kinase (FN3K) is involved in the deglycation of Nrf2, a significant regulator of oxidative stress in cancer cells. However, the intricate functional aspects of FN3K and Nrf2 in breast cancers have not been explored vividly. The objectives of this study are to design the human FN3K protein using homology modeling followed by the screening of several anticancer molecules and examining their efficacy to modulate FN3K activity, Nrf2-mediated antioxidant signalling. Methods pertinent to homology modeling, virtual screening, molecular docking, molecular dynamics simulations, assessment of ADME properties, cytotoxicity assays for anticancer molecules of natural/synthetic origin in breast cancer cells (BT-474, T-47D), and Western blotting were used in this study. The screened anticancer molecules including kinase inhibitors of natural and synthetic origin interacted with the 3-dimensional structure of the catalytic domain in human FN3K protein designed through homology modeling by significant CDOCKER interaction energies. Subsequently, gefitinib, sorafenib, neratinib, tamoxifen citrate, and cyclosporine A enhanced the expression of FN3K in BT-474 cell lines with simultaneous alteration in Nrf2-driven antioxidant signalling. Oxaliplatin significantly downregulated FN3K expression and modulated Nrf2-driven antioxidant signalling when compared to cisplatin and other anticancer drugs. Hence, the study concluded the potential implications of existing anticancer drugs to modulate FN3K activity in breast cancers.

The strategies to cure cancer patients by eradicating cancer stem-like cells

Cancer stem-like cells (CSCs), a subpopulation of cancer cells, possess remarkable capability in proliferation, self-renewal, and differentiation. Their presence is recognized as a crucial factor contributing to tumor progression and metastasis. CSCs have garnered significant attention as a therapeutic focus and an etiologic root of treatment-resistant cells. Increasing evidence indicated that specific biomarkers, aberrant activated pathways, immunosuppressive tumor microenvironment (TME), and immunoevasion are considered the culprits in the occurrence of CSCs and the maintenance of CSCs properties including multi-directional differentiation. Targeting CSC biomarkers, stemness-associated pathways, TME, immunoevasion and inducing CSCs differentiation improve CSCs eradication and, therefore, cancer treatment. This review comprehensively summarized these targeted therapies, along with their current status in clinical trials. By exploring and implementing strategies aimed at eradicating CSCs, researchers aim to improve cancer treatment outcomes and overcome the challenges posed by CSC-mediated therapy resistance.

EpCAM tumor specificity and proteoform patterns in urothelial cancer

BACKGROUND

The role of the epithelial cell adhesion molecule (EpCAM) in cancer is still unclear. EpCAM cleavage through regulated intramembrane proteolysis results in fragments which interact with both oncogenic and tumor suppressive pathways. Additionally, the EpCAM molecule itself is used as a descriptive therapeutic target in urothelial cancer (UC), while data on its actual tumor specificity remain limited.

METHODS

Samples from diagnostic formalin-fixed paraffin-embedded (FFPE) UC tissue and fresh-frozen UC cells were immunoblotted and used for qualitative characterization of five different EpCAM fragments. These expression patterns were quantified across a cohort of 76 samples with 52 UC and 24 normal urothelial samples. Cell viability effects of the extracellular EpEX fragment were assessed in the UC cell lines T24 and HT1376.

RESULTS

The proteolytic EpCAM fragments could be identified in clinical FFPE tissue specimens too. Neither overall nor fragment-specific EpCAM expression showed relevant tumor specificity. EpEX and its deglycosylated variant showed an inverse relationship across healthy and tumor tissue with a decrease of deglycosylated EpEX in tumors. However, extracellular EpEX did not show a relevant effect in vitro.

CONCLUSIONS

EpCAM should not be regarded as tumor-specific in UC without patient-specific predictive testing. EpCAM fragment patterns indicate cancer-specific changes and could be involved in its complex tumor-biological role.

Updated Clinical Perspectives and Challenges of Chimeric Antigen Receptor-T Cell Therapy in Colorectal Cancer and Invasive Breast Cancer

In recent years, the incidence of colorectal cancer (CRC) and breast cancer (BC) has increased worldwide and caused a higher mortality rate due to the lack of selective anti-tumor therapies. Current chemotherapies and surgical interventions are significantly preferred modalities to treat CRC or BC in advanced stages but the prognosis for patients with advanced CRC and BC remains dismal. The immunotherapy technique of chimeric antigen receptor (CAR)-T cells has resulted in significant clinical outcomes when treating hematologic malignancies. The novel CAR-T therapy target antigens include GUCY2C, CLEC14A, CD26, TEM8/ANTXR1, PDPN, PTK7, PODXL, CD44, CD19, CD20, CD22, BCMA, GD2, Mesothelin, TAG-72, CEA, EGFR, B7H3, HER2, IL13Ra2, MUC1, EpCAM, PSMA, PSCA, NKG2D. The significant aim of this review is to explore the recently updated information pertinent to several novel targets of CAR-T for CRC, and BC. We vividly described the challenges of CAR-T therapies when treating CRC or BC. The immunosuppressive microenvironment of solid tumors, the shortage of tumor-specific antigens, and post-treatment side effects are the major hindrances to promoting the development of CAR-T cells. Several clinical trials related to CAR-T immunotherapy against CRC or BC have already been in progress. This review benefits academicians, clinicians, and clinical oncologists to explore more about the novel CAR-T targets and overcome the challenges during this therapy.

Cytosolic EpCAM cooperates with H-Ras to regulate epithelial to mesenchymal transition through ZEB1

Next generation sequencing of human cancer mutations has identified novel therapeutic targets. Activating Ras oncogene mutations play a central role in oncogenesis, and Ras-driven tumorigenesis upregulates an array of genes and signaling cascades that can transform normal cells into tumor cells. In this study, we investigated the role of altered localization of epithelial cell adhesion molecule (EpCAM) in Ras-expressing cells. Analysis of microarray data demonstrated that Ras expression induced EpCAM expression in normal breast epithelial cells. Fluorescent and confocal microscopy showed that H-Ras mediated transformation also promoted epithelial-to-mesenchymal transition (EMT) together with EpCAM. To consistently localize EpCAM in the cytosol, we generated a cancer-associated EpCAM mutant (EpCAM-L240A) that is retained in the cytosol compartment. Normal MCF-10A cells were transduced with H-Ras together with EpCAM wild-type (WT) or EpCAM-L240A. WT-EpCAM marginally effected invasion, proliferation, and soft agar growth. EpCAM-L240A, however, markedly altered cells and transformed to mesenchymal phenotype. Ras-EpCAM-L240A expression also promoted expression of EMT factors FRA1, ZEB1 with inflammatory cytokines IL-6, IL-8, and IL1. This altered morphology was reversed using MEK-specific inhibitors and to some extent JNK inhibition. Furthermore, these transformed cells were sensitized to apoptosis using paclitaxel and quercetin, but not other therapies. For the first time, we have demonstrated that EpCAM mutations can cooperate with H-Ras and promote EMT. Collectively, our results highlight future therapeutic opportunities in EpCAM and Ras mutated cancers.

Intelligent recognition of CTCs from gallbladder cancer by ultrasensitive electrochemical cytosensor and diagnosis of chemotherapeutic resistance

Gallbladder carcinoma (GBC) is one of most aggressive and lethal malignancies. Early diagnosis of GBC is crucial for determining appropriate treatment and improving chances of cure. Chemotherapy represents the main therapeutic regimen for unresectable GBC patients to inhibit tumor growth & metastasis. But, chemoresistance is the major cause of GBC recurrence. Thus, there is an urgent need to explore potentially non-invasive and point-of-care approaches to screen GBC and monitor their chemoresistance. Herein, we established an electrochemical cytosensor to specifically detect circulating tumor cells (CTCs) and their chemoresistance. Trilayer of CdSe/ZnS quantum dots (QDs) were cladded upon SiO₂ nanoparticles (NPs), forming Tri-QDs/PEI@SiO₂ electrochemical probes. Upon conjugation of anti-ENPP1, the electrochemical probes were able to specifically label captured CTCs from GBC. The detection of CTCs and chemoresistance were realized by square wave anodic stripping voltammetric (SWASV) responses to anodic stripping current of Cd ²⁺ ion when cadmium in electrochemical probes was dissolved and eventually electrodeposited on bismuth film-modified glassy carbon electrode (BFE). Taking use of this cytosensor, one ensured the screening of GBC and limit of detection for CTCs approaches to ～10 cells/mL. Furthermore, by monitoring phenotypic changes of CTCs after drug treatment, the diagnosis of chemoresistance was achieved by our cytosensor.

Single-Cell Enzymatic Screening for Epithelial Mesenchymal Transition with an Ultrasensitive Superwetting Droplet-Array Microchip

The phenotypic changes of circulating tumor cells (CTCs) during the epithelial-mesenchymal transition (EMT) have been a hot topic in tumor biology and cancer therapeutic development. Here, an integrated platform of single-cell fluorescent enzymatic assays with superwetting droplet-array microchips (SDAM) for ultrasensitive functional screening of epithelial-mesenchymal sub-phenotypes of CTCs is reported. The SDAM can generate high-density, volume well-defined droplet (0.66 nL per droplet) arrays isolating single tumor cells via a discontinuous dewetting effect. It enables sensitive detection of MMP9 enzyme activities secreted by single tumor cells, correlating to their epithelial-mesenchymal sub-phenotypes. In the pilot clinical double-blind tests, the authors have demonstrated that SDAM assays allow for rapid identification and functional screening of CTCs with different epithelial-mesenchymal properties. The consistency with the clinical outcomes validates the usefulness of single-cell secreted MMP9 as a biomarker for selective CTC screening and tumor metastasis monitoring. Convenient addressing and recovery of individual CTCs from SDAM have been demonstrated for gene mutation sequencing, immunostaining, and transcriptome analysis, revealing new understandings of the signaling pathways between MMP9 secretion and the EMT regulation of CTCs. The SDAM approach combined with sequencing technologies promises to explore the dynamic EMT plasticity of tumors at the single-cell level.

The role of N-glycosylation modification in the pathogenesis of liver cancer

N-glycosylation is one of the most common types of protein modifications and it plays a vital role in normal physiological processes. However, aberrant N-glycan modifications are closely associated with the pathogenesis of diverse diseases, including processes such as malignant transformation and tumor progression. It is known that the N-glycan conformation of the associated glycoproteins is altered during different stages of hepatocarcinogenesis. Characterizing the heterogeneity and biological functions of glycans in liver cancer patients will facilitate a deeper understanding of the molecular mechanisms of liver injury and hepatocarcinogenesis. In this article, we review the role of N-glycosylation in hepatocarcinogenesis, focusing on epithelial-mesenchymal transition, extracellular matrix changes, and tumor microenvironment formation. We highlight the role of N-glycosylation in the pathogenesis of liver cancer and its potential applications in the treatment or diagnosis of liver cancer.

The role of N-glycosylation modification in the pathogenesis of liver cancer

N-glycosylation is one of the most common types of protein modifications and it plays a vital role in normal physiological processes. However, aberrant N-glycan modifications are closely associated with the pathogenesis of diverse diseases, including processes such as malignant transformation and tumor progression. It is known that the N-glycan conformation of the associated glycoproteins is altered during different stages of hepatocarcinogenesis. Characterizing the heterogeneity and biological functions of glycans in liver cancer patients will facilitate a deeper understanding of the molecular mechanisms of liver injury and hepatocarcinogenesis. In this article, we review the role of N-glycosylation in hepatocarcinogenesis, focusing on epithelial-mesenchymal transition, extracellular matrix changes, and tumor microenvironment formation. We highlight the role of N-glycosylation in the pathogenesis of liver cancer and its potential applications in the treatment or diagnosis of liver cancer.

Microtubule-associated protein 4 promotes epithelial mesenchymal transition in hepatocellular cancer cells via regulating GSK3β/β-catenin pathway

Metastasis is a major obstacle in the treatment of hepatocellular carcinoma (HCC). Microtubule-associated protein 4 (MAP4) plays an important role as a coordinator between microtubules and microfilaments. However, the role of MAP4 in HCC migration and epithelial mesenchymal transition (EMT) is unclear. We compared the protein and mRNA levels of MAP4 in human HCC and adjacent normal tissues using western blotting, immunohistochemistry and RT-qPCR. The migration and invasion abilities and the levels of EMT markers (E-Cadherin, N-Cadherin, Vimentin, and Snail) were compared between MAP4-knockdown and MAP4-overexpressed HCC cells. Finally, we examined whether β-catenin and glycogen synthase kinase 3β (GSK3β) are involved in the stimulatory effects of MAP4 on HCC migration, invasion and EMT. The results revealed that MAP4 levels were higher in the HCC tissues than in the normal hepatic tissues. More importantly, MAP4 knockdown suppressed migration and invasion abilities and EMT processes in HCC cells, which were confirmed by the stimulatory effects of MAP4 overexpression on EMT processes in HCC cells. Further evidence demonstrated that the up-regulation of β-catenin activity induced by the interaction between MAP4 and GSK3β possibly accounted for the pro-migration and pro-EMT effects of MAP4 on HCC cells. Taken together, these results suggest that MAP4 promotes migration, invasion, and EMT in HCC cells by regulating the GSK3β/β-catenin pathway.

Epitope Mapping of an Anti-EpCAM Monoclonal Antibody (EpMab-37) Using the Alanine Scanning Method

The epithelial cell adhesion molecule (EpCAM) is a type I transmembrane glycoprotein, and plays critical roles in cell adhesion, proliferation, and tumorigenesis. EpCAM has been considered as a promising target for tumor diagnosis and therapy. Anti-EpCAM monoclonal antibodies (mAbs) have been developed for EpCAM-overexpressed tumors, and several clinical trials have demonstrated promising outcomes. We previously established an anti-EpCAM mAb, EpMab-37 (mouse IgG₁, kappa), using the Cell-Based Immunization and Screening method. EpMab-37 was revealed to recognize the conformational epitope of EpCAM. In this study, we determined the critical epitope of EpMab-37 by flow cytometry using the 1 × alanine scanning (1 × Ala-scan) and the 2 × alanine scanning (2 × Ala-scan) method. We first performed flow cytometry by 1 × Ala-scan using one alanine (or glycine)-substituted EpCAM mutants, which were expressed on Chinese hamster ovary-K1 cells, and found that the EpMab-37 did not recognize the R163A mutant of EpCAM. We next performed flow cytometry by 2 × Ala-scan using two alanine (or glycine) residues-substituted EpCAM mutants, and confirmed that EpMab-37 did not recognize R163A-including mutants of EpCAM. The results indicated that the critical binding epitope of EpMab-37 includes Arg163 of EpCAM.

Antitumor activities of a defucosylated anti‑EpCAM monoclonal antibody in colorectal carcinoma xenograft models

Epithelial cell adhesion molecule (EpCAM) is a type I transmembrane glycoprotein, which is highly expressed on tumor cells. As EpCAM plays a crucial role in cell adhesion, survival, proliferation, stemness, and tumorigenesis, it has been considered as a promising target for tumor diagnosis and therapy. Anti‑EpCAM monoclonal antibodies (mAbs) have been developed and have previously demonstrated promising outcomes in several clinical trials. An anti‑EpCAM mAb, EpMab‑37 (mouse IgG₁, kappa) was previously developed by the authors, using the cell‑based immunization and screening method. In the present study, a defucosylated version of anti‑EpCAM mAb (EpMab‑37‑mG2a‑f) was generated to evaluate the antitumor activity against EpCAM‑positive cells. EpMab‑37‑mG_2a‑f recognized EpCAM‑overexpressing CHO‑K1 (CHO/EpCAM) cells with a moderate binding‑affinity [dissociation constant (K_D)=2.2x10^‑8 M] using flow cytometry. EpMab‑37‑mG_2a‑f exhibited potent antibody‑dependent cellular cytotoxicity (ADCC) and complement‑dependent cytotoxicity (CDC) for CHO/EpCAM cells by murine splenocytes and complements, respectively. Furthermore, the administration of EpMab‑37‑mG_2a‑f significantly suppressed CHO/EpCAM xenograft tumor development compared with the control mouse IgG. EpMab‑37‑mG_2a‑f also exhibited a moderate binding‑affinity (K_D=1.5x10^‑8 M) and high ADCC and CDC activities for a colorectal cancer cell line (Caco‑2 cells). The administration of EpMab‑37‑mG_2a‑f to Caco‑2 tumor‑bearing mice significantly suppressed tumor development compared with the control. By contrast, EpMab‑37‑mG_2a‑f never suppressed the xenograft tumor growth of Caco‑2 cells in which EpCAM was knocked out. On the whole, these results indicate that EpMab‑37‑mG_2a‑f may exert antitumor activities against EpCAM‑positive cancers and may thus be a promising therapeutic regimen for colorectal cancer.

Current understanding of cancer stem cells: Immune evasion and targeted immunotherapy in gastrointestinal malignancies

As a relatively rare population of cancer cells existing in the tumor microenvironment, cancer stem cells (CSCs) possess properties of immune privilege to evade the attack of immune system, regulated by the microenvironment of CSCs, the so-called CSCs niche. The bidirectional interaction of CSCs with tumor microenvironment (TME) components favors an immunosuppressive shelter for CSCs' survival and maintenance. Gastrointestinal cancer stem cells (GCSCs) are broadly regarded to be intimately involved in tumor initiation, progression, metastasis and recurrence, with elevated tumor resistance to conventional therapies, which pose a major hindrance to the clinical efficacy for treated patients with gastrointestinal malignancies. Thus, a multitude of efforts have been made to combat and eradicate GCSCs within the tumor mass. Among diverse methods of targeting CSCs in gastrointestinal malignancies, immunotherapy represents a promising strategy. And the better understanding of GCSCs immunomodulation and immunoresistance mechanisms is beneficial to guide and design novel GCSCs-specific immunotherapies with enhanced immune response and clinical efficacy. In this review, we have gathered available and updated information to present an overview of the immunoevasion features harbored by cancer stem cells, and we focus on the description of immune escape strategies utilized by CSCs and microenvironmental regulations underlying CSCs immuno-suppression in the context of gastrointestinal malignancies. Importantly, this review offers deep insights into recent advances of CSC-targeting immunotherapeutic approaches in gastrointestinal cancers.

Recent progress in molecular mechanisms of postoperative recurrence and metastasis of hepatocellular carcinoma

Hepatectomy is currently considered the most effective option for treating patients with early and intermediate hepatocellular carcinoma (HCC). Unfortunately, the postoperative prognosis of patients with HCC remains unsatisfactory, predominantly because of high postoperative metastasis and recurrence rates. Therefore, research on the molecular mechanisms of postoperative HCC metastasis and recurrence will help develop effective intervention measures to prevent or delay HCC metastasis and recurrence and to improve the long-term survival of HCC patients. Herein, we review the latest research progress on the molecular mechanisms underlying postoperative HCC metastasis and recurrence to lay a foundation for improving the understanding of HCC metastasis and recurrence and for developing more precise prevention and intervention strategies.

A Defucosylated Anti-EpCAM Monoclonal Antibody (EpMab-37-mG2a-f) Exerts Antitumor Activity in Xenograft Model

The epithelial cell adhesion molecule (EpCAM) is a stem cell and carcinoma antigen, which mediates cellular adhesion and proliferative signaling by the proteolytic cleavage. In contrast to low expression in normal epithelium, EpCAM is frequently overexpressed in various carcinomas, which correlates with poor prognosis. Therefore, EpCAM has been considered as a promising target for tumor diagnosis and therapy. Using the Cell-Based Immunization and Screening (CBIS) method, we previously established an anti-EpCAM monoclonal antibody (EpMab-37; mouse IgG₁, kappa). In this study, we investigated the antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and an antitumor activity by a defucosylated mouse IgG_2a-type of EpMab-37 (EpMab-37-mG_2a-f) against a breast cancer cell line (BT-474) and a pancreatic cancer cell line (Capan-2), both of which express EpCAM. EpMab-37-mG_2a-f recognized BT-474 and Capan-2 cells with a moderate binding-affinity [apparent dissociation constant (K_D): 2.9 × 10^-8 M and 1.8 × 10^-8 M, respectively] by flow cytometry. EpMab-37-mG_2a-f exhibited ADCC and CDC for both cells by murine splenocytes and complements, respectively. Furthermore, administration of EpMab-37-mG_2a-f significantly suppressed the xenograft tumor development compared with the control mouse IgG. These results indicated that EpMab-37-mG_2a-f exerts antitumor activities and could provide valuable therapeutic regimen for breast and pancreatic cancers.

Label-Free Imaging Analysis of Patient-Derived Cholangiocarcinoma Organoids after Sorafenib Treatment

Monitoring tumor growth dynamics is crucial for understanding cancer. To establish an in vitro method for the continuous assessment of patient-specific tumor growth, tumor organoids were generated from patients with intrahepatic CCA (iCCA). Organoid growth was monitored for 48 h by label-free live brightfield imaging. Growth kinetics were calculated and validated by MTS assay as well as immunohistochemistry of Ki67 to determine proliferation rates. We exposed iCCA organoids (iCCAOs) and non-tumor intrahepatic cholangiocyte organoids (ICOs) to sub-therapeutic concentrations of sorafenib. Monitoring the expansion rate of iCCAOs and ICOs revealed that iCCAO growth was inhibited by sorafenib in a time- and dose-dependent fashion, while ICOs were unaffected. Quantification of the proliferation marker Ki67 confirmed inhibition of iCCAO growth by roughly 50% after 48 h of treatment with 4 µM sorafenib. We established a robust analysis pipeline combining brightfield microscopy and a straightforward image processing approach for the label-free growth monitoring of patient-derived iCCAOs. Combined with bioanalytical validation, this approach is suitable for a fast and efficient high-throughput drug screening in tumor organoids to develop patient-specific systemic treatment options.

Development of a Novel Anti-EpCAM Monoclonal Antibody for Various Applications

The epithelial cell adhesion molecule (EpCAM) is a cell surface glycoprotein, which is widely expressed on normal and cancer cells. EpCAM is involved in cell adhesion, proliferation, survival, stemness, and tumorigenesis. Therefore, EpCAM is thought to be a promising target for cancer diagnosis and therapy. In this study, we established anti-EpCAM monoclonal antibodies (mAbs) using the Cell-Based Immunization and Screening (CBIS) method. We characterized them using flow cytometry, Western blotting, and immunohistochemistry. One of the established recombinant anti-EpCAM mAbs, recEpMab-37 (mouse IgG₁, kappa), reacted with EpCAM-overexpressed Chinese hamster ovary-K1 cells (CHO/EpCAM) or a colorectal carcinoma cell line (Caco-2). In contrast, recEpMab-37 did not react with EpCAM-knocked out Caco-2 cells. The K_D of recEpMab-37 for CHO/EpCAM and Caco-2 was 2.0 × 10⁻⁸ M and 3.2 × 10⁻⁸ M, respectively. We observed that EpCAM amino acids between 144 to 164 are involved in recEpMab-37 binding. In Western blot analysis, recEpMab-37 detected the EpCAM of CHO/EpCAM and Caco-2 cells. Furthermore, recEpMab-37 could stain formalin-fixed paraffin-embedded colorectal carcinoma tissues by immunohistochemistry. Taken together, recEpMab-37, established by the CBIS method, is useful for detecting EpCAM in various applications.

The Relevance of Circadian Clocks to Stem Cell Differentiation and Cancer Progression

The molecular mechanism of circadian clocks depends on transcription-translation feedback loops (TTFLs) that have known effects on key cellular processes. However, the distinct role of circadian TTFLs in mammalian stem cells and other less differentiated cells remains poorly understood. Neural stem cells (NSCs) of the brain generate neurons and glia postnatally but also may become cancer stem cells (CSCs), particularly in astrocytomas. Evidence indicates clock TTFL impairment is needed for tumor growth and progression; although, this issue has been examined primarily in more differentiated cancer cells rather than CSCs. Similarly, few studies have examined circadian rhythms in NSCs. After decades of research, it is now well recognized that tumors consist of CSCs and a range of other cancer cells along with noncancerous stromal cells. The circadian properties of these many contributors to tumor properties and treatment outcome are being widely explored. New molecular tools and ones in development will likely enable greater discrimination of important circadian and non-circadian cells within malignancies at multiple stages of cancer progression and following therapy. Here, we focus on adult NSCs and glioma CSCs to address how cells at different stages of differentiation may harbor unique states of the molecular circadian clock influencing differentiation and cell fate.

Bladder cancer cell lines adapt their aggressiveness profile to oxygen tension

During the process of tumor growth, cancer cells will be subjected to intermittent hypoxia. This results from the delay in the development of the vascular network in relation to the proliferation of cancer cells. The hypoxic nature of a tumor has been demonstrated as a negative factor for patient survival. To evaluate the impact of hypoxia on the survival and migration properties of low and high-grade bladder cancer cell lines, two low-grade (MGHU-3 and SW-780) and two high-grade (SW-1710 and T24) bladder cancer cell lines were cultured in normoxic (20% O₂) or hypoxic atmospheric conditions (2% O₂). The response of bladder cancer cell lines to hypoxic atmospheric cell culture conditions was examined under several parameters, including epithelial-mesenchymal transition, doubling time and metabolic activities, thrombospondin-1 expression, whole Matrix Metallo-Proteinase activity, migration and resistance to oxidative stress. The low-grade cell line response to hypoxia was heterogeneous even if it tended to adopt a more aggressive profile. Hypoxia enhanced migration and pro-survival properties of MGHU-3 cells, whereas these features were reduced for the SW-780 cell line cultured under low oxygen tension. The responses of tested high-grade cell lines were more homogeneous and tended to adopt a less aggressive profile. Hypoxia drastically changed some of the bladder cancer cell line properties, for example matrix metalloproteinases expression for all cancer cells but also switch in glycolytic metabolism of low grade cancer cells. Overall, studying bladder cancer cells in hypoxic environments are relevant for the translation from in vitro findings to in vivo context.

Dynamic Monitoring of EMT in CTCs as an Indicator of Cancer Metastasis

Epithelial to mesenchymal transition (EMT) results in the genesis of circulating tumor cells (CTCs) from tumor sites and promotes the metastatic capability of CTCs in circulation. In this study, we develop a multiplex surface-enhanced Raman scattering nanotechnology for comprehensive characterization of EMT-associated phenotypes in CTCs, to monitor cancer metastasis. We observe the downregulation of the CTC marker (EpCAM) and the epithelial marker (E-cadherin), as well as the upregulation of a mesenchymal marker (N-cadherin) and a stem cell marker (ABCB5) during the transforming growth factor-β-induced EMT process in breast cancer cell line models. Additionally, we also find changes in the heterogeneity levels of these selected markers in cells. With this method, we successfully detect the presence of disease in samples from breast cancer patients and characterize EMT-associated phenotypes in their CTCs. Overall, this approach and findings provide a new means for monitoring the EMT process in cancer, insights into the detailed mechanistic progress of the diseases, and have potential for detecting the early occurrence of cancer metastasis.

Single-particle analysis of tear fluid reveals abundant presence of tissue factor-exposing extracellular vesicles with strong coagulation activity

Extracellular vesicles (EVs) in easily accessible body fluids have emerged as a promising source for liquid biopsy. Although tear collection is fast, safe, and noninvasive, EVs of tear fluid are less studied and their involvement in physiological and pathological processes is largely unknown. The aim of present study was to analyze and characterize EVs in tear fluid at the single-particle level to reveal the population heterogeneity. A laboratory-built nano-flow cytometer (nFCM) was used to analyze the purity, size distribution, and particle concentration of EVs isolated from unstimulated tears (basal tears) upon double ultracentrifugation (17 min at 100,000×g, 4 °C) via side scattering detection. The expression of CD9, CD63, CD81, CD47, CD45, CD24, and EpCAM was assessed via immunofluorescent detection. The EV concentration in tear fluid was measured to be 1.1 ± 0.7 × 10¹¹ particles/mL, which is approximately 100-fold higher than that of plasma EVs. In particular, it was identified for the first time that tears have strong coagulant activity owing to the abundant presence of tissue factor (TF) on tear EVs. The concentration of TF-exposing EVs (4.4 ± 3.1 × 10¹⁰ particles/mL) was found to be approximately 100-fold higher than their counterparts in saliva (4.5 ± 2.1 × 10⁸ particles/mL). We postulate that TF-exposing vesicles in tears might play a role in host defense by promoting clot formation and thus reducing the risk of pathogen invasion. The coagulant activity of tears triggered by TF-exposing EVs could provide a new research perspective for ophthalmic research.

Interactome analysis reveals endocytosis and membrane recycling of EpCAM during differentiation of embryonic stem cells and carcinoma cells

Transmembrane epithelial cell adhesion molecule (EpCAM) is expressed in epithelia, carcinoma, teratoma, and embryonic stem cells (ESCs). EpCAM displays spatiotemporal patterning during embryogenesis, tissue morphogenesis, cell differentiation, and epithelial-to-mesenchymal transition (EMT) in carcinomas. Potential interactors of EpCAM were identified in murine F9 teratoma cells using a stable isotope labeling with amino acids in cell culture-based proteomic approach (n = 77, enrichment factor >3, p value ≤ 0.05). Kyoto Encyclopedia of Genes and Genomes and gene ontology terms revealed interactions with regulators of endosomal trafficking and membrane recycling, which were further validated for Rab5, Rab7, and Rab11. Endocytosis and membrane recycling of EpCAM were confirmed in mF9 cells, E14TG2α ESC, and Kyse30 carcinoma cells. Reduction of EpCAM during mesodermal differentiation and TGFβ-induced EMT correlated with enhanced endocytosis and block or reduction of recycling in ESCs and esophageal carcinoma cells. Hence, endocytosis and membrane recycling are means of regulation of EpCAM protein levels during differentiation of ESC and EMT induction in carcinoma cells.