Loss of CDH1 (E-cadherin) expression is associated with infiltrative tumour growth and lymph node metastasis

EMMPRIN promotes spheroid organization and metastatic formation: comparison between monolayers and spheroids of CT26 colon carcinoma cells

Background

In vitro studies often use two-dimensional (2D) monolayers, but 3D cell organization, such as in spheroids, better mimics the complexity of solid tumors. To metastasize, cancer cells undergo the process of epithelial-to-mesenchymal transition (EMT) to become more invasive and pro-angiogenic, with expression of both epithelial and mesenchymal markers.

Aims

We asked whether EMMPRIN/CD147 contributes to the formation of the 3D spheroid structure, and whether spheroids, which are often used to study proliferation and drug resistance, could better model the EMT process and the metastatic properties of cells, and improve our understanding of the role of EMMPRIN in them.

Methods

We used the parental mouse CT26 colon carcinoma (CT26-WT) cells, and infected them with a lentivirus vector to knock down EMMPRIN expression (CT26-KD cells), or with an empty lentivirus vector (CT26-NC) that served as a negative control. In some cases, we repeated the experiments with the 4T1 or LLC cell lines. We compared the magnitude of change between CT26-KD and CT26-WT/NC cells in different metastatic properties in cells seeded as monolayers or as spheroids formed by the scaffold-free liquid overlay method.

Results

We show that reduced EMMPRIN expression changed the morphology of cells and their spatial organization in both 2D and 3D models. The 3D models more clearly demonstrated how reduced EMMPRIN expression inhibited proliferation and the angiogenic potential, while it enhanced drug resistance, invasiveness, and EMT status, and moreover it enhanced cell dormancy and prevented CT26-KD cells from forming metastatic-like lesions when seeded on basement membrane extract (BME). Most interestingly, this approach enabled us to identify that EMMPRIN and miR-146a-5p form a negative feedback loop, thus identifying a key mechanism for EMMPRIN activities. These results underline EMMPRIN role as a gatekeeper that prevents dormancy, and suggest that EMMPRIN links EMT characteristics to the process of spheroid formation.

Conclusions

Thus, 3D models can help identify mechanisms by which EMMPRIN facilitates tumor and metastasis progression, which might render EMMPRIN as a promising target for anti-metastatic tumor therapy.

Anaplastic thyroid cancer spheroids as preclinical models to test therapeutics

Anaplastic thyroid cancer (ATC) is the most aggressive thyroid cancer. Despite advances in tissue culture techniques, a robust model for ATC spheroid culture is yet to be developed. In this study, we created an efficient and cost-effective 3D tumor spheroids culture system from human ATC cells and existing cell lines that better mimic patient tumors and that can enhance our understanding of in vivo treatment response. We found that patient-derived ATC cells and cell lines can readily form spheroids in culture with a unique morphology, size, and cytoskeletal organization. We observed both cohesive (dense and solid structures) and discohesive (irregularly shaped structures) spheroids within the same culture condition across different cell lines. BRAFWT ATC spheroids grew in a cohesive pattern, while BRAFV600E-mutant ATC spheroids had a discohesive organization. In the patient-derived BRAFV600E-mutant ATC spheroids, we observed both growth patterns, but mostly the discohesive type. Histologically, ATC spheroids had a similar morphology to the patient's tumor through H&E staining and proliferation marker staining. Moreover, RNA sequencing analysis revealed that the gene expression profile of tumor cells derived from the spheroids closely matched parental patient tumor-derived cells in comparison to monolayer cultures. In addition, treatment response to combined BRAF and MEK inhibition in BRAFV600E-mutant ATC spheroids exhibited a similar sensitivity to the patient clinical response. Our study provides a robust and novel ex vivo spheroid model system that can be used in both established ATC cell lines and patient-derived tumor samples to better understand the biology of ATC and to test therapeutics.

Sodium orthovanadate exhibits anti-angiogenic, antiapoptotic and blood glucose-lowering effect on colon cancer associated with diabetes

BACKGROUND

The presence of type 2 diabetes mellitus increases the risk of developing the colon cancer. The main objective of this study was to determine the role of sodium orthovanadate (SOV) in colon cancer associated with diabetes mellitus by targeting the competitive inhibition of PTP1B.

METHODS

For in vivo study, high fat diet with low dose streptozotocin model was used for inducing the diabetes mellitus. Colon cancer was induced by injecting 1,2-dimethylhydrazine (25 mg/kg, sc) twice a week. TNM staging and immunohistochemistry (IHC) was carried out for colon cancer tissues. In vitro studies like MTT assay, clonogenic assay, rhodamine-123 dye assay and annexin V-FITC assay using flow cytometry were performed on HCT-116 cell line. CAM assay was performed to examine the anti-angiogenic effect of the drug.

RESULTS

Sodium orthovanadate reduces the blood glucose level and tumor parameters in the animals. In vitro studies revealed that SOV decreased cell proliferation dose dependently. In addition, SOV induced apoptosis as depicted from rhodamine-123 dye assay and annexin V-FITC assay using flow cytometry as well as p53 IHC staining. SOV showed reduced angiogenesis effect on eggs which was depicted from CAM assay and also from CD34 and E-cadherin IHC staining.

CONCLUSIONS

Our data suggest that SOV exhibits protective role in colon cancer associated with diabetes mellitus. SOV exhibits anti-proliferative, anti-angiogenic and apoptotic inducing effects hence can be considered for therapeutic switching in diabetic colon cancer.

PATHOLOGICAL SIGNIFICANCE OF CDH1/E-CADHERIN GERMLINE SEQUENCE VARIANTS IN BREAST CANCER PATIENTS

BACKGROUND

Germline alterations of the CDH1 (E-cadherin) tumor suppressor gene have been reported in several epithelial malignancies like hereditary diffuse gastric cancer and lobular breast cancer. E-cadherin plays a central role in proliferation, maintenance of cell-to-cell adhesion, polarity, and epithelial-mesenchymal transition of tissue cells. It is necessary to analyze the impact of the CDH1 germline sequence variants on protein and predict its clinical significance in breast cancer (BC) progression. The aim of the current study was to evaluate the impact and association of CDH1 gene potentially pathogenic variants/likely pathogenic variants (PVs/LPVs) with the initiation and progression of BC.

MATERIALS AND METHODS

In this study, the clinical data of 200 BC patients have been analyzed based on the type of BC, age, grade, stage, hormonal status, and risk factors. Blood samples from 50 healthy donors were used as a control. Furthermore, CDH1 gene molecular analysis, along with in silico analysis, was provided to assess the invasiveness and progression of BC caused by the E-cadherin protein.

RESULTS

Four variants were identified by genetic screening within the CDH1 gene that included variations in exons 7, 8, 10, 11, and 13. Exon 10 had splice site mutation at position c.1337C>A, affecting the protein structure. In exon 11, there was an insertion of T base at position 1669, resulting in truncated protein compared to a normal one that can lead to the disease-causing non- sense-mediated decay and exon 13 variant c.2076T>C has already known polymorphism. In silico analysis of CDH1 showed the presence of the different variants that indicated the overall disruption of protein structure and function.

CONCLUSIONS

The further functional analysis of these variants and their association with BC can be ensured by increasing the sample size and in vivo studies using mouse models.

E-Cadherin Expression Varies Depending on the Location within the Primary Tumor and Is Higher in Colorectal Cancer with Lymphoid Follicles

Reliable indicators of cancer advancement have actively been sought recently. The detection of colorectal cancer progression markers is essential in improving diagnostic and therapeutic protocols. The aim of the study was to investigate the profile of E-cadherin expression in colorectal cancer tissue depending on the TNM staging and its correlation with several clinical and histopathological features. The study included 55 colorectal cancer patients admitted to the surgical ward for elective surgery. Tissue samples were obtained from resected specimens. Different distributions of E-cadherin expression within tumors were observed; the highest percentage of positive E-cadherin expression was found in the invasive front and in the tumor center. Additionally, the different cellular distribution of E-cadherin expression was noticed; weak membranous E-cadherin expression was the highest in the invasive front and in the budding sites, but a strong membranous pattern was most frequent in the tumor center. Various distributions of E-cadherin expression depending on cancer progression were also found; E-cadherin expression in node-positive patients was lower in the tumor center and in the tumor invasive front, whereas, in patients with distant metastases, the expression of E-Cadherin was lower in the budding sites. In patients with higher TNM stages, E-cadherin expression was lower within the tumor (in the budding sites, tumor center, and invasive front). In tumors with lymphoid follicles, E-cadherin expression was higher in all localizations within the primary tumor. E-cadherin expression in the tumor center was also lower in tumors with some higher tumor budding parameters (areas of poorly differentiated components and poorly differentiated clusters). E-cadherin expression was found to be lower at the tumor center in younger individuals, at the budding sites in men, and at the surrounding lymph nodes in rectal tumors. Low E-cadherin expression appears to be a reliable indicator of higher cancer staging and progression. When assessing the advancement of cancer, apart from the TNM classification, it is beneficial to also consider the expression of E-cadherin. High tumor budding, the poverty of lymphoid follicles, and low E-cadherin expression analyzed simultaneously may contribute to a reliable assessment of colorectal cancer staging. These three histopathological features complement each other, and their investigation, together with conventional tumor staging and grading, may be very helpful in predicting the prognosis of colorectal cancer patients and qualifying them for the best treatment. The role of E-cadherin in the diagnosis and treatment of colorectal cancer, as a part of a personalized medicine strategy, still requires comprehensive, prospective clinical evaluations to precisely target the optimal therapies for the right patients at the right time.

Inferring spatial transcriptomics markers from whole slide images to characterize metastasis-related spatial heterogeneity of colorectal tumors: A pilot study

Over 150 000 Americans are diagnosed with colorectal cancer (CRC) every year, and annually over 50 000 individuals will die from CRC, necessitating improvements in screening, prognostication, disease management, and therapeutic options. Tumor metastasis is the primary factor related to the risk of recurrence and mortality. Yet, screening for nodal and distant metastasis is costly, and invasive and incomplete resection may hamper adequate assessment. Signatures of the tumor-immune microenvironment (TIME) at the primary site can provide valuable insights into the aggressiveness of the tumor and the effectiveness of various treatment options. Spatially resolved transcriptomics technologies offer an unprecedented characterization of TIME through high multiplexing, yet their scope is constrained by cost. Meanwhile, it has long been suspected that histological, cytological, and macroarchitectural tissue characteristics correlate well with molecular information (e.g., gene expression). Thus, a method for predicting transcriptomics data through inference of RNA patterns from whole slide images (WSI) is a key step in studying metastasis at scale. In this work, we collected tissue from 4 stage-III (pT3) matched colorectal cancer patients for spatial transcriptomics profiling. The Visium spatial transcriptomics (ST) assay was used to measure transcript abundance for 17 943 genes at up to 5000 55-micron (i.e., 1-10 cells) spots per patient sampled in a honeycomb pattern, co-registered with hematoxylin and eosin (H&E) stained WSI. The Visium ST assay can measure expression at these spots through tissue permeabilization of mRNAs, which are captured through spatially (i.e., x-y positional coordinates) barcoded, gene specific oligo probes. WSI subimages were extracted around each co-registered Visium spot and were used to predict the expression at these spots using machine learning models. We prototyped and compared several convolutional, transformer, and graph convolutional neural networks to predict spatial RNA patterns at the Visium spots under the hypothesis that the transformer- and graph-based approaches better capture relevant spatial tissue architecture. We further analyzed the model's ability to recapitulate spatial autocorrelation statistics using SPARK and SpatialDE. Overall, the results indicate that the transformer- and graph-based approaches were unable to outperform the convolutional neural network architecture, though they exhibited optimal performance for relevant disease-associated genes. Initial findings suggest that different neural networks that operate on different scales are relevant for capturing distinct disease pathways (e.g., epithelial to mesenchymal transition). We add further evidence that deep learning models can accurately predict gene expression in whole slide images and comment on understudied factors which may increase its external applicability (e.g., tissue context). Our preliminary work will motivate further investigation of inference for molecular patterns from whole slide images as metastasis predictors and in other applications.

Combined Infiltrative Macroscopic Growth Pattern and Infiltrative Microscopic Tumor Border Status Is a Novel Surrogate Marker of Poor Prognosis in Patients With Pancreatic Neuroendocrine Tumor

CONTEXT.—

Pancreatic neuroendocrine tumors (PanNETs) are heterogeneous tumors with a wide range of malignant potential. Therefore, identification of prognostic factors is essential.

OBJECTIVE.—

To systematically assess the significance of tumor border, a well-known prognostic indicator in other cancers, in PanNETs.

DESIGN.—

We evaluated the macroscopic growth pattern (expansile [Exp] versus infiltrative [Inf]) and the microscopic tumor border (pushing [Pus] versus Inf) of 203 surgically resected PanNETs and compared them with other clinicopathologic factors.

RESULTS.—

Based on macroscopic growth pattern, 83 cases had Exp patterns whereas 84 had Inf patterns. According to microscopic tumor border, 122 PanNETs had Pus borders whereas 81 had Inf borders. Combining macroscopic growth pattern and microscopic tumor border, 65 PanNETs had Exp/Pus, 34 had Inf/Pus, 18 had Exp/Inf, and 50 had Inf/Inf status. PanNETs with Inf/Inf status were associated with higher tumor grade, pT classification, and American Joint Committee on Cancer stage grouping; lymph node metastasis; and lymphovascular and perineural invasions (all P < .001). Patients with PanNET having Inf/Inf status had significantly shorter overall survival (OS) and recurrence-free survival (RFS; all P < .001). Further, using multivariate analysis, Inf/Inf status was identified as an independent poor prognostic factor of OS (P = .02) and RFS (P = .03).

CONCLUSIONS.—

In summary, combined Inf/Inf status was observed in approximately 25% of PanNETs and was associated with aggressive biological behavior and short OS and RFS. Therefore, assessing combined macroscopic growth pattern and microscopic tumor border can provide additional information regarding survival and recurrence in PanNET patients.

Association between CDH1 methylation and esophageal cancer risk: a meta-analysis and bioinformatics study

OBJECTIVE

The aim is to evaluate the association of CDH1 methylation with esophageal cancer (EC) risk.

METHODS

The PubMed, Embase, Web of Science, and Cochrane Library databases were systematically searched to identify relevant articles. Pooled odds ratios (ORs) with 95% confidence interval (CI) were estimated using the fixed- or random-effects models. The pooled sensitivity and specificity were calculated to assess the diagnostic value of CDH1 methylation for EC. The results of the meta-analysis were validated using The Cancer Genome Atlas and Gene Expression Omnibus databases.

RESULTS

Thirteen studies consisting of 1,633 samples were included. A high CDH1 methylation was significantly associated with an increased risk of EC (OR = 10.40, 95% CI = 6.29-17.18). Furthermore, CDH1 methylation status was related to tumor status, lymph node status, and metastasis. For the diagnosis of EC, the pooled sensitivity and specificity of CDH1 methylation were 0.57 (95% CI = 0.39-0.74) and 0.89 (95% CI = 0.81-0.94), respectively. Bioinformatics analysis showed that CDH1 methylation occurred more frequently in EC tissues than in normal controls, in good agreement with the results of the meta-analysis.

CONCLUSION

A significant association was found between CDH1 methylation and EC risk. We therefore suggest that CDH1 methylation can serve as a promising diagnostic marker for EC.

Effect of E-cadherin on Prognosis of Colorectal Cancer: A Meta-Analysis Update

PURPOSE

The effect of E-cadherin on colorectal cancer is still controversial. In order to clarify the effect of E-cadherin on the prognosis and clinicopathological features of colorectal cancer, a meta-analysis was conducted.

METHODS

PubMed, Embase and Cochrane Library were used to collect all relevant literature published before November 2021, and the corresponding data was extracted to analyze the correlation between the expression of E-cadherin and the prognosis and clinicopathological features of colorectal cancer. In addition, the Gene Expression Profiling Interactive Analysis (GEPIA) was used to validate our results.

RESULTS

Fifty-two studies, including 9591 patients, were included in this meta-analysis. According to the meta-analysis, low expression of E-cadherin was significantly associated with shorter overall survival (OS) (hazard ratio [HR] 2.09, 95% confidence interval [CI]1.67-2.62; Z = 6.42, p = 0.000) and disease-free survival (DFS) (HR 2.03, 95% CI 1.71-2.42; Z = 7.95, p = 0.000). In addition, low expression of E-cadherin resulted in higher risk of low differentiation (odds ratio [OR] 0.35, 95% CI 0.25-0.50; p = 0.000), high risk of distant metastasis (OR 0.45, 95% CI 0.35-0.58; p = 0.000), high risk of vascular invasion (OR 0.61, 95% CI 0.45-0.83; p = 0.002), higher risk of lymph node metastasis (OR 0.54, 95% CI 0.42-0.69; p = 0.000), high risk of lymphatic invasion (OR 0.56, 95% CI 0.40-0.80; p = 0.001), high risk of deep infiltration (OR 0.63, 95% CI 0.50-0.80; p = 0.000), later TNM stage (OR 0.60, 95% CI 0.46-0.78; p = 0.000) and late Dukes' stage (OR 0.35,95% CI 0.25-0.49; p = 0.000), but wasn't associated with tumor size (OR 0.90, 95% CI 0.71-1.15; p = 0.406).The results of GEPIA showed that E-cadherin mRNA expression in colorectal cancer tumor tissues and normal tissues had no difference, and had no effect on OS and DFS.

CONCLUSION

Although not supported by GEPIA, our meta-analysis provided abundant data to suggest that low expression of E-cadherin is associated with poor prognosis in colorectal cancer patients and is an important factor influencing adverse clinicopathological features. Therefore, E-cadherin may be used to predict the prognosis of colorectal cancer and provide guidance for clinical treatment.

5-fluorouracil treatment of patient-derived scaffolds from colorectal cancer reveal clinically critical information

BACKGROUND

Colorectal cancer is a commonly diagnosed cancer worldwide. Unfortunately, many patients do not respond to standard chemotherapy treatments and develop disease relapse and metastases. Besides cancer cell specific genetic changes, heterogeneity in the tumor microenvironment contribute to the clinical presentation of the disease and can potentially also influence drug resistance. By using a recently developed patient-derived scaffold method monitoring how a standardized reporter cancer cell line adapts to various microenvironments treated with chemotherapy, we wanted to clarify how individual patient specific microenvironments influence the chemotherapy response in colorectal cancer.

METHODS

Surgically resected colorectal cancer specimens from 89 patients were decellularized to produce patient-derived scaffold, which were seeded with HT29 cells, cultured for 3 weeks, and treated with 5-fluorouracil. Gene expression changes of adapted and treated HT29 cells were monitored by qPCR and compared with clinical parameters including disease-free survival.

RESULTS

The effects of 5-fluorouracil treatment varied between different patient-derived scaffold, but generally induced a reduced expression of proliferation genes and increased expression of pluripotency and epithelial-to-mesenchymal transition genes. Interestingly, patient-derived scaffold cultures obtained from patients with disease recurrences showed a significantly less pronounced anti-proliferative effect of 5-fluorouracil and more pronounced increase of pluripotency, with MKI67 and POU5F1 being among the most significant genes linked to disease relapse in colorectal cancer.

CONCLUSIONS

Colorectal patient-derived scaffold can decode clinically relevant tumor microenvironmental influence of 5-fluorouracil treatment effects opening up for optimized precision medicine in colorectal cancer treatment.

Investigation of the expression levels of CDH1, FHIT, PTEN, and TTPAL genes in colorectal tumors

BACKGROUND

The main aim of the study is to assess expression levels of CDH1, FHIT, PTEN, and TTPAL genes in tumors and peripheral bloods of colorectal cancer patients in staged I-IV.

METHODS

Gene expression analysis of related genes were performed for tumor tissues and peripheral blood samples of 51 colorectal cancer patients and colon tissues and blood samples of 5 healthy individuals. The real-time-PCR reaction method was used for the analysis.

RESULTS

Alteration of mRNA levels of related genes in tumor tissues of colorectal cancer cases was determined compared to control tissues. GAPDH and TBP were used for the normalization. While the mRNA levels of CDH1 decreased, the mRNA level of the FHIT and TTPAL genes increased in the tumor tissues. There was no PTEN gene expression difference in tumor tissues (total). The mRNA levels of the CDH1 and PTEN genes were increased while the mRNA levels of FHIT and TTPAL genes decreased in the blood (total). T he mRNA levels of the CDH1 gene decreased at each stage (I-IV) in the tumor tissues and increased at each stage (I-IV) in the blood. T he PTEN gene mRNA levels at each stage were controversial. The mRNA levels of the FHIT gene increased at stage I-II-III, decreased at stage IV in the tissues and decreased at each stage (I-IV) in the blood. The mRNA levels of TTPAL gene increased at each stage (I-IV) in the tissues and decreased at each stage (I-IV) in the blood.

The Potential Role of CDH1 as an Oncogene Combined With Related miRNAs and Their Diagnostic Value in Breast Cancer

BACKGROUND

Breast cancer (BC) is the leading cause of cancer-related mortality in females and the most common malignancy with high morbidity worldwide. It is imperative to develop new biomarkers and therapeutic targets for early diagnosis and effective treatment in BC.

METHODS

We revealed the oncogene function of cadherin 1 (CDH1) via bioinformatic analysis in BC. Moreover, miRNA database was utilized to predict miRNAs upstream of CDH1. Expression of CDH1-related miRNAs in BC and their values in BC stemness and prognosis were analyzed through TCGA-BRCA datasets. In addition, Gene Ontology (GO) and Gene Set Enrichment Analysis (GSEA) were performed to explore the potential functions and signaling pathways of CDH1 in combination with CDH1-related miRNAs in BC progression. Finally, the differential expressions of soluble E-cadherin (sE-cad), which is formed by the secretion of CDH1-encoded E-cadherin into serum, analyzed by enzyme-linked immunosorbent assay (ELISA). Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) was used to detect the expression level of CDH1-related miRNAs in serum samples.

RESULTS

The mRNA and protein expressions of CDH1 were elevated in BC tissues compared with normal counterparts. Moreover, CDH1 overexpression was positively correlated with BC stage, metastatic, stemness characteristics, and poor prognosis among patients. In predictive analysis, miR-340, miR-185, and miR-20a target CDH1 and are highly expressed in BC. miR-20a overexpression alone was strongly associated with high stemness characteristics and poor prognosis of BC. Additionally, GO, KEGG, and hallmark effect gene set analysis demonstrated that CDH1 in combination with overexpression of miR-340, miR-185, or miR-20a participated in multiple biological processes and underly signaling pathways involving in tumorigenesis and development of BC. Finally, we provide experimental evidence that the combined determination of serum sE-cad and miR-20a in BC has highly diagnostic efficiency.

CONCLUSIONS

This study provides evidence for CDH1 as an oncogene in BC and suggests that miR-20a may regulate the stemness characteristics of BC to exert a pro-oncogenic effect by regulating CDH1. Moreover, sE-cad and miR-20a in serum can both be used as valid noninvasive markers for BC diagnosis.

Entrectinib Induces Apoptosis and Inhibits the Epithelial-Mesenchymal Transition in Gastric Cancer with NTRK Overexpression

Tropomyosin receptor kinase (TRK) and receptor tyrosine kinase (RTK class VII) expression are important in many human diseases, especially cancers, including colorectal, lung, and gastric cancer. Using RNA sequencing analysis, we evaluated the mRNA expression and mutation profiles of gastric cancer patients with neurotropic tropomyosin receptor kinase (NTRK) 1-3 overexpression (defined as a ≥2.0-fold change). Furthermore, we screened eight TRK inhibitors in NCI-N87, SNU16, MKN28, MKN7, and AGS cells. Among these inhibitors, entrectinib showed the highest inhibitory activity; therefore, this drug was selected for analysis of its therapeutic mechanisms in gastric cancer. Entrectinib treatment induced apoptosis in NTRK1-3-expressing and VEGFR2-expressing NCI-N87 and AGS cells, but it had no effect on NTRK1-3-, VEGFR2-, TGFBR1-, and CD274-expressing MKN7 cells. SNU16 and MKN28 cells with low NTRK1-3 expression were not affected by entrectinib. Therefore, a mechanistic study was conducted in NCI-N87 (high expression of NTRK1-3 but mutation of NTRK3), AGS (high expression of NTRK1-3) and MKN28 (low expression of NTRK1-3) gastric cancer cell lines. Entrectinib treatment significantly reduced expression levels of phosphorylated NFκB, AKT, ERK, and β-catenin in NCI-N87 and AGS cells, whereas it upregulated the expression levels of ECAD in NCI-N87 cells. Together, these results suggest that entrectinib has anti-cancer activity not only in GC cells overexpressing pan NTRK but also in VEGFR2 GC cells via the inhibition of the pan NTRK and VEGFR signaling pathways.

Paxillin Promotes Breast Tumor Collective Cell Invasion through Maintenance of Adherens Junction Integrity

Distant organ metastasis is linked to poor prognosis during cancer progression. The expression level of the focal adhesion adapter protein paxillin varies among different human cancers, but its role in tumor progression is unclear. Herein, we utilize a newly generated PyMT mammary tumor mouse model with conditional paxillin ablation in breast tumor epithelial cells, combined with in vitro 3D tumor organoids invasion analysis and 2D calcium switch assays, to assess the roles for paxillin in breast tumor cell invasion. Paxillin had little effect on primary tumor initiation and growth but is critical for the formation of distant lung metastasis. In paxillin-depleted 3D tumor organoids, collective cell invasion was substantially perturbed. Two-dimensional cell culture revealed paxillin-dependent stabilization of adherens junctions (AJ). Mechanistically, paxillin is required for AJ assembly through facilitating E-cadherin endocytosis and recycling and HDAC6-mediated microtubule acetylation. Furthermore, Rho GTPase activity analysis and rescue experiments with a RhoA activator or Rac1 inhibitor suggest paxillin is potentially regulating the E-cadherin-dependent junction integrity and contractility through control of the balance of RhoA and Rac1 activities. Together, these data highlight new roles for paxillin in the regulation of cell-cell adhesion and collective tumor cell migration to promote the formation of distance organ metastases. [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text].

Tetrandrine Inhibits Epithelial-Mesenchymal Transition in IL-6-Induced HCT116 Human Colorectal Cancer Cells

Introduction

Patients with colorectal cancer (CRC) often develop distant metastases, which significantly reduces the 5-year survival rate. Epithelial-mesenchymal transition (EMT) is a crucial process for the invasion and metastasis of cancer cells. Tetrandrine has been reported to inhibit the viability and EMT of CRC cells; however, to the best of our knowledge, the molecular mechanism remains undetermined.

Methods

The MTT assay was used to determine HCT116 cell viability. Wound healing and Transwell assays were used to determine that cell migration and invasion, respectively. Western blotting analysis was performed to detect the expression of migration-related genes. Four different lengths of the E-cadherin gene promoter were constructed and cloned into pGL3 reporter plasmids to evaluate E-cadherin gene promoter activity.

Results

The results of the MTT assay revealed that tetrandrine inhibited HCT116 cell viability, with an IC₅₀ value of 7.2 μM following 24 h of treatment. Tetrandrine inhibited IL-6-induced cell migration and invasion, respectively. Tetrandrine regulates the expression of migration-related genes in IL-6-stimulated HCT116 cells. Tetrandrine significantly downregulated the expression and enzyme activity of MMP-2 in IL-6-stimulated HCT116 cells. In addition, tetrandrine restored E-cadherin gene promoter activity.

Conclusion

The findings of the present study suggested that tetrandrine may inhibit EMT in IL-6-stimulated HCT116 cells; therefore, it may represent a potential drug for CRC.

Differences in the Expression of β-Catenin Nucleus/Cytoplasm Ratio e-Cadherin and n-Cadherin and Correlation of β-Catenin Cytoplasm and Cadherin in Model of Duke D Stage Colorectal Cancer Cell Line

BACKGROUND: β-catenin has a critical role in the homeostasis processes. Wnt/β-catenin signaling mainly involved in the modulation of cancer cell development. AIM: This research aimed to investigate the differences of β-catenin expression observed in the form of nucleus–cytoplasm ratio, the differences of E-cadherin and N-cadherin expressions, and the correlation between N-cadherin and E-cadherin and β-catenin cytoplasm in Dukes D stage colorectal cancer (CRC), which is an advanced stage and has experienced metastasis. MATERIALS AND METHODS: This study followed an experimental research design. The processes of culture manufacturing and subculture preparation of Dukes D stage CRC cell line model were performed before the administration of β-catenin, E-cadherin, and N-cadherin antibodies. The next process was staining using fluorescein-5-isothiocyanate and rhodamine, and observations were performed using a confocal microscope. The number of cells was counted, and the intensity of antibody expression based on the arbitrary unit was measured. RESULTS: There was a significant difference between the expression of β-catenin nucleus and cytoplasm expression (p = 0.00), as well as between E-cadherin expression and N-cadherin expression (p = 0.00). In addition, a correlation also existed between an increased N-cadherin expression and decreased E-cadherin expression and β-catenin cytoplasm in Dukes D stage CRC, but the results were not significant (p = 0.837 and p = 0.108). CONCLUSION: In advanced-stage CRC (Dukes D), the Wnt signaling proved to be active and was characterized by a high expression of β-catenin nucleus, it activates the target gene. Similarly, at the Dukes D stage, N-cadherin expression increased whereas E-cadherin expression decreased in which causing the translocation of β-catenin into the nucleus.

The correlation of epithelial-mesenchymal transition-related gene expression and the clinicopathologic features of colorectal cancer patients in Taiwan

Colorectal cancer (CRC) is the third most commonly diagnosed malignancy and the second leading cause of cancer-related deaths in the world. It has been the most prevalent malignancy in Taiwan for consecutive thirteen years. Despite the diversity of its etiologic and pathophysiologic factors, a biological process named as epithelial-mesenchymal transition (EMT) is indispensable in the progression of epithelial cancer. Our aim is to investigate the correlation between the expression of 8 EMT-related proteins (E-cadherin, β-catenin, claudin-1, CD44, N-cadherin, fibronectin, vimentin, S100A4) and the clinicopathologic features of CRC in Taiwan, along with the DNA CpG epigenetic status of CD44 gene. In immunohistochemical assessment, decreased expression of E-cadherin is statistically associated with the progression of cancer stage, while decreased expression of claudin-1 as well as increased β-catenin nuclear translocation and N-cadherin expression is statistically associated with the progression of histopathologic grade. E-cadherin, nuclear β-catenin and claudin-1 are also associated with other important prognostic factors, including nodal metastasis, tumor deposits, and elevated serum CA 19-9 levels. In addition, the left-sided colon and rectal cancers show increased nuclear translocation of β-catenin compared to the right-sided colon cancers, while the rectal cancers show increased fibronectin expression compared to the right-sided and left-sided colon cancers. Moreover, vimentin is aberrantly expressed in one case of signet-ring cell carcinoma. The DNA methylation levels of CD44 gene promoter between the tumoral and non-tumorous tissues by NGS comparison showed statistical difference on six CpG sites. However, such difference may not be sufficient because these DNA methylation proportions are too low to inactivate CD44 gene. Our results demonstrate the expression of E-cadherin, claudin-1, and nuclear β-catenin is closely related to the clinicopathologic prognostic determinants of CRC in Taiwan. The DNA methylation level of CD44 gene and its protein expression, however, show no correlation with the clinicopathologic features in CRC.

The Role of Calcium Signaling in Regulation of Epithelial-Mesenchymal Transition

Despite substantial advances in the field of cancer therapeutics, metastasis is a significant challenge for a favorable clinical outcome. Epithelial to mesenchymal transition (EMT) is a process of acquiring increased motility, invasiveness, and therapeutic resistance by cancer cells for their sustained growth and survival. A plethora of intrinsic mechanisms and extrinsic microenvironmental factors drive the process of cancer metastasis. Calcium (Ca2+) signaling plays a critical role in dictating the adaptive metastatic cell behavior comprising of cell migration, invasion, angiogenesis, and intravasation. By modulating EMT, Ca2+ signaling can regulate the complexity and dynamics of events leading to metastasis. This review summarizes the role of Ca2+ signal remodeling in the regulation of EMT and metastasis in cancer.

Expression pattern of ALDH1, E-cadherin, Vimentin and Twist in early and late onset sporadic colorectal cancer

Aim: To evaluate the expression pattern of ALDH1 (aldehyde dehydrogenase 1), E-cadherin, Vimentin and Twist in early and late onset sporadic colorectal cancer (CRC) and to study association of their expression with the occurrence of CRC at a young age. Materials & methods: Immunohistochemistry of ALDH1, E-cadherin, Vimentin and Twist was performed on 103 pretreated CRC biopsy samples. Results: ALDH1 expression was found to have strong correlation with early onset CRC (p < 0.0001). Conclusion: High ALDH1 expression correlates with the early onset of CRC. ALDH1 over-expression correlates with poor overall survival in colon cancer.

Prognostic significance of E-cadherin and Cox 2 expression in Tunisian patients with colorectal mucinous adenocarcinoma

INTRODUCTION

Mucinous colorectal carcinoma (MC) is a rare subtype of colorectal adenocarcinoma known to be associated with bad prognosis. Lately, research has turned to identify new prognostic markers allowing the use of targeted therapy. The aim of our study is to evaluate the prognostic impact of E-cadherin and Cox-2expression in MC.

MATERIALS AND METHOD

A total of 40 formalin-fixed, paraffin-embedded MC specimens were collected within a period of 13 years and were studied for the expression of the two proteins. We used SPSS 22 software to study associations with clinicopathological parameters and overall survival (OS).

RESULTS

A reduced or absent E-cadherin expression was noted in 52.5% of cases. It was associated with distant metastases (p = 0.049) and venous invasion (p = 0.049). Cox-2 was overexpressed in 17.5% of cases. It was associated with negative lymph node status (p = 0.020) and with early stage tumor (p = 0.020). A significant association between the two proteins was also noted (p = 0.04). No significant association with OS was found; However, there was an improvement in the survival of patients overexpressing Cox-2 (p = 0.16).

CONCLUSION

Our findings link the loss of E-cadherin expression with spread and aggressiveness in MC and Cox-2 overexpression with better prognosis and survival. Because MC has a distinct genetic pathway we encourage the analysis of MSI and Cox-2 expression in all MC. Cox-2 inhibitors may not be effective chemopreventative agents in the setting of defective DNA mismatch repair. More molecular studies are needed to better understand the role of these markers and their prognostic significance in MC.

Tumour budding, poorly differentiated clusters, and T-cell response in colorectal cancer

BACKGROUND

Tumour budding and poorly differentiated clusters (PDC) represent forms of tumour invasion. We hypothesised that T-cell densities (reflecting adaptive anti-tumour immunity) might be inversely associated with tumour budding and PDC in colorectal carcinoma.

METHODS

Utilising 915 colon and rectal carcinomas in two U.S.-wide prospective cohort studies, and multiplex immunofluorescence combined with machine learning algorithms, we assessed CD3, CD4, CD8, CD45RO (PTPRC), and FOXP3 co-expression patterns in lymphocytes. Tumour budding and PDC at invasive fronts were quantified by digital pathology and image analysis using the International tumour Budding Consensus Conference criteria. Using covariate data of 4,420 incident colorectal cancer cases, inverse probability weighting (IPW) was integrated with multivariable logistic regression analysis that assessed the association of T-cell subset densities with tumour budding and PDC while adjusting for selection bias due to tissue availability and potential confounders, including microsatellite instability status.

FINDINGS

Tumour budding counts were inversely associated with density of CD3⁺CD8⁺ [lowest vs. highest: multivariable odds ratio (OR), 0.50; 95% confidence interval (CI), 0.35-0.70; P_trend < 0.001] and CD3⁺CD8⁺CD45RO⁺ cells (lowest vs. highest: multivariable OR, 0.44; 95% CI, 0.31-0.63; P_trend < 0.001) in tumour epithelial region. Tumour budding levels were associated with higher colorectal cancer-specific mortality (multivariable hazard ratio, 2.13; 95% CI, 1.57-2.89; P_trend < 0.001) in Cox regression analysis. There were no significant associations of PDC with T-cell subsets.

INTERPRETATION

Tumour epithelial naïve and memory cytotoxic T cell densities are inversely associated with tumour budding at invasive fronts, suggesting that cytotoxic anti-tumour immunity suppresses tumour microinvasion.

Molecular testing on bronchial washings for the diagnosis and predictive assessment of lung cancer

Cytopathological analyses of bronchial washings (BWs) collected during fibre‐optic bronchoscopy are often inconclusive for lung cancer diagnosis. To address this issue, we assessed the suitability of conducting molecular analyses on BWs, with the aim to improve the diagnosis and outcome prediction of lung cancer. The methylation status of RASSF1A, CDH1, DLC1 and PRPH was analysed in BW samples from 91 lung cancer patients and 31 controls, using a novel two‐colour droplet digital methylation‐specific PCR (ddMSP) technique. Mutations in ALK, BRAF, EGFR, ERBB2, KRAS, MAP2K1, MET, NRAS, PIK3CA, ROS1 and TP53 and gene fusions of ALK, RET and ROS1 were also investigated, using next‐generation sequencing on 73 lung cancer patients and 14 tumour‐free individuals. Our four‐gene methylation panel had significant diagnostic power, with 97% sensitivity and 74% specificity (relative risk, 7.3; odds ratio, 6.1; 95% confidence interval, 12.7–127). In contrast, gene mutation analysis had a remarkable value for predictive, but not for diagnostic, purposes. Actionable mutations in EGFR, HER2 and ROS1 as well as in other cancer genes (KRAS, PIK3CA and TP53) were detected. Concordance with gene mutations uncovered in tumour biopsies was higher than 90%. In addition, bronchial‐washing analyses permitted complete patient coverage and the detection of additional actionable mutations. In conclusion, BWs are a useful material on which to perform molecular tests based on gene panels: aberrant gene methylation and mutation analyses could be performed as approaches accompanying current diagnostic and predictive assays during the initial workup phase. This study establishes the grounds for further prospective investigation.

Cadherins down-regulation: towards a better understanding of their relevance in colorectal cancer

The down-regulation of cadherin expression in colorectal cancer (CRC) has been widely studied. However, existing data on cadherin expression are highly variable and its relevance to CRC development has not been completely established. This review examines published studies on cadherins whose down-regulation has been already demonstrated in CRC, trying to establish a relationship with promoter methylation, the capacity to influence the Wnt / CTNNB1 (catenin beta 1, beta-catenin) signalling pathway and the clinical implications for disease outcome. Moreover, it also analyses factors that may explain data variability and highlights the importance of considering the altered subcellular localization of the examined cadherins. The results of this survey reveal that thirty of one hundred existing cadherins appear to be down-regulated in CRC. Among these, ten are cadherins, sixteen are protocadherins, equally divided between clustered and non clustered, and four are cadherin - related. These findings suggest that, to better define the role played by cadherin down-regulation in CRC pathogenesis, the expression of multiple rather than individual cadherins should be taken into account and further functional studies are necessary to clarify the relative ability of individual cadherins to inhibit CTNNB1 therefore acting as tumor suppressors.

Targeted next-generation sequencing of matched localized and metastatic primary high-risk SCCs identifies driver and co-occurring mutations and novel therapeutic targets

BACKGROUND

Cutaneous squamous cell carcinoma (SCC) is the second most common type of skin cancer and is responsible for over one million cases annually. While only 3-5 % of SCCs metastasize, those that do are associated with significant morbidity and mortality. Using gene mutations to help predict metastasis and select therapeutics is still being explored.

OBJECTIVE

To present novel data from targeted sequencing of 20 case-matched localized and metastatic high-risk SCCs.

METHODS

A cancer-associated gene panel of 76 genes was run from formalin-fixed paraffin-embedded samples of 20 case-matched localized (10) and metastatic (10) high-risk SCCs (Vela Diagnostics).

RESULTS

Using spatial clustering analysis, primary driver mutations were identified asEGFR in localized SCC and CDH1 in metastatic SCC. ERBB4 and STK11 were found to be significant co-occurring mutations in localized SCC. Pathway analyses showed the RTK/RAS, TP53, TGF-b, NOTCH1, PI3K, and cell cycle pathways to be highly relevant in all high-risk SCCs with the Wnt pathway enhanced in metastatic SCC only.

CONCLUSIONS

This study compared gene mutations between localized and metastatic SCC with the intent of identifying key differences and new potential targeted treatment options. To our knowledge, the co-occurrence ofERBB4 and STK11 mutations has not been previously reported. Targeted inhibition of CDH1 and the Wnt pathway should be further explored in metastatic SCC.

YAP promotes epithelial mesenchymal transition by upregulating Slug expression in human colorectal cancer cells

Yes-associated protein (YAP) contributes to the development of multiple tumors, including colorectal cancer (CRC). However, the underlying mechanisms involved in YAP-induced CRC migration and invasion are not fully elucidated. By performing immunohistochemistry (IHC), we found that YAP is highly expressed in CRC tissues and significantly correlated with invasive depth. The expression of YAP was elevated in CRC cell lines. Therefore, we sought to illustrate whether the up-regulation of YAP contributes to CRC the epithelial-mesenchymal transition (EMT). Here migration and transwell assays showed that YAP overexpression promoted migration and invasion inCRC cells. YAP knockdown inhibited migration and invasion in CRC cells. Furthermore, western blotting showed that CRC YAP overexpression causes the down-regulation of the epithelial marker E-cadherin and the up-regulation of the EMT-related transcription factor Slug, which in turn promotes the EMT in CRC. YAP knockdown inhibited EMT by up-regulating E-cadherin and down-regulating Slug. Furthermore, in YAP-overexpressing CRC cells, Slug knockdown promoted E-cadherin expression and inhibited EMT. In CRC cells with low expression of YAP, high expression of Slug can inhibit E-cadherin expression and promote EMT. Importantly, luciferase assays confirmed that YAP directly transcriptionally activated Slug expression. Based on the above results, our study shows that YAP is a driver of EMT in CRC, which inhibits E-cadherin expression by activating transcriptional Slug expression.

[Hereditary gastric cancer: Challenges for the pathologist in 2020]

Gastric cancer is the third most common cancer worldwide. The majority of gastric cancers are sporadic but familial clustering is seen in more than 10% of cases. This manuscript is divided into two parts. The first part is dedicated to the non-syndromic hereditary gastric cancer, particularly the hereditary diffuse gastric cancer (HDGC) and other gastric polyposes including the recently described GAPPS (Gastric adenocarcinoma and proximal polyposis of the stomach). The second part concerns the syndromic gastric cancer, namely the HNPCC syndrome (Hereditary Non Polyposis Colorectal Cancer) occurring as part of a genetic predisposition syndrome to cancer. Recent advances in oncogenetics and next generation sequencing technology have enabled the identification of new entities. This enhancement in knowledge regarding inherited syndromes predisposing to gastric cancer has consequently improved the management of patients and their families. In this context, pathologists play a major role in identifying particular morphologic entities prompting genetic investigation. The aim of this manuscript is to provide an update on the current knowledge about hereditary gastric cancer.

CDH1 gene mutation in early-onset, colorectal signet-ring cell carcinoma

AIM

Colorectal signet-ring cell carcinomas (SRCC) are highly malignant tumours with poor prognosis that disproportionately affect younger patients. There is growing evidence of a unique set of molecular features that separate SRCC from conventional colorectal adenocarcinoma. Identification of these distinct features may have diagnostic and prognostic significance for patients and families. CDH1, which encodes E-cadherin, a cell adhesion protein, is commonly mutated in gastric SRCC and our study aimed to identify whether CDH1 mutation was also a common phenomenon in colorectal SRCC.

METHODS

DNA was extracted from formalin-fixed paraffin embedded tumour tissue, the CDH1 gene was analysed by next generation sequencing and the pathogenicity of mutations assessed in silico. Sections cut from the same blocks were immunostained to identify the presence of the E-cadherin protein.

RESULTS

We found 8 CDH1 mutations that meet our inclusion criteria in seven of 11 samples. Of these, five (from four patients), were likely to be germline mutations. E-cadherin staining was absent or markedly reduced in all of the seven samples with CDH1 mutation.

CONCLUSION

Our finding of CDH1 mutations in a proportion of signet-ring cell carcinomas and associated reduction in E-cadherin in these tumours supports previous findings of a role for mutation of this gene in the development of this disease. In addition, the finding of likely germline mutations suggests that a subset of these tumours may be familial. Loss of E-cadherin staining in the absence of CDH1 mutations however also suggests a role for environmental factors in a subset of these tumours.

Cdh1 functions as an oncogene by inducing self-renewal of lung cancer stem-like cells via oncogenic pathways

The mortality rate of lung cancer remains the highest amongst all cancers despite of new therapeutic developments. While cancer stem cells (CSCs) may play a pivotal role in cancer, mechanisms underlying CSCs self-renewal and their relevance to cancer progression have not been clearly elucidated due to the lack of reliable and stable CSC cellular models. In the present study, we unveiled the novel oncogene function of cadherin 1 (Cdh1) via bioinformatic analysis in a broad spectrum of human cancers including lung adenocarcinoma (LUAD), adding a new dimension to the widely reported tumor suppressor function of Cdh1. Experimentally, we show for the first time that Cdh1 promotes the self-renewal of lung CSCs, consistent with its function in embryonic and normal stem cells. Using the LLC-Symmetric Division (LLC-SD) model, we have revealed an intricate cross-talk between the oncogenic pathway and stem cell pathway in which Cdh1 functions as an oncogene by promoting lung CSC renewal via the activation of the Phosphoinositide 3-kinase (PI3K) and inhibition of Mitogen-activated protein kinase (MAPK) pathways, respectively. In summary, this study has provided evidence demonstrating effective utilization of the normal stem cell renewal mechanisms by CSCs to promote oncogenesis and progression.

Next generation DNA sequencing of atypical choroid plexus papilloma of brain: Identification of novel mutations in a female patient by Ion Proton

Choroid plexus papilloma (CPP) is a rare benign tumor of the central nervous system that is usually confined to the cerebral ventricles. According to the World Health Organization, CPP corresponds to a grade I atypical CPP (a-CPP); however, it can become more aggressive and reach grade II, which can rarely undergo malignant transformation into a choroid plexus carcinoma (grade III). To the best of our knowledge, identification of these tumors mutations by next generation DNA sequencing (NGS) has not been yet reported. In the present study, NGS analysis of an a-CPP case was performed. Data were analyzed using Advaita Bioinformatics i-VariantGuide and Ion Reporter 5.6 programs. The results from NGS identified 12 novel missense mutations in the following genes: NOTCH1, ATM, STK36, MAGI1, DST, RECQL4, NUMA1, THBS1, MYH11, MALT1, SMARCA4 and CDH20. The PolyPhen score of six variants viz., DST, RECQL4, NUMA1, THBS1, MYHI1 and SMARCA4 were high, which suggested these variants represents pathogenic variants. Two novel insertions that caused frameshift were also found. Furthermore, two novel nonsense mutations and 14 novel intronic variants were identified in this tumor. The novel missense mutation detected in ATM gene was situated in c.5808A>T; p. (Leu1936Phe) in exon 39, and a known ATM mutation was in c.5948A>G; p. (Asn1983Ser). These novel mutations had not been reported in previous database. Subsequently, the quality statistics of these variants, including allele coverage, allele ratio, P-value, Phred quality score, sequencing coverage, PolyPhen score and alleles frequency was performed. For all variants, P-value was highly significant and the Phred quality score was high. In addition, the results from sequencing coverage demonstrated that 97.02% reads were on target and that 97.88% amplicons had at least 500 reads. These findings may serve at determining new strategies to distinguish the types of choroid plexus tumor, and at developing novel targeted therapies. Development of NGS technologies in the Kingdom of Saudi Arabia may be used in molecular pathology laboratories.

E-cadherin Downregulation and microRNAs in Sporadic Intestinal-Type Gastric Cancer

CDH1 gene, encoding E-cadherin, is a tumor suppressor gene frequently altered in gastric cancers (GCs) of both diffuse (DGC) and intestinal (IGC) histotypes, albeit through different mechanisms. The study aimed to characterize CDH1 expression in sporadic IGC and to investigate whether microRNAs (miRs) are involved in its transcriptional control. We evaluated CDH1 expression by quantitative real-time PCR (RT-qPCR) in 33 IGC patients and found a significant downregulation in tumor tissues compared to normal counterparts (p-value = 0.025). Moreover, 14 miRs, predicted to be involved in CDH1 regulation in both a direct and indirect manner, were selected and analyzed by RT-qPCR in an independent case series of 17 IGCs and matched normal tissues. miR-101, miR-26b, and miR-200c emerged as significantly downregulated and were confirmed in the case series of 33 patients (p-value < 0.001). Finally, we evaluated EZH2 expression, a target of both miR-101 and miR-26b, which showed significant upregulation in IGCs (p-value = 0.005). A significant inverse correlation was observed between EZH2 overexpression and CDH1, miR-101, and miR-26b levels (p-value < 0.001). Our results reinforce the link between CDH1 and IGC, highlighting the role of miRs in its transcriptional control and improving our understanding of GC subtypes and biomarkers.

E-cadherin is required for metastasis in multiple models of breast cancer

Metastasis is the major driver of cancer deaths and begins when cancer cells invade surrounding tissues. Invasion and metastasis have been proposed to initiate following loss of the intercellular adhesion protein, E-cadherin (E-cad)^1,2, based upon inverse correlations between in vitro migration and E-cad levels³. This hypothesis is inconsistent, however, with the observation that most breast cancers are invasive ductal carcinomas (IDC) and express E-cad in primary tumors and metastases⁴. To resolve this discrepancy, we tested the genetic requirement for E-cad in metastasis using murine and human models of both luminal and basal IDC. Here we show that E-cad promotes metastasis in IDC. While loss of E-cad increased invasion, it also reduced cancer cell proliferation and survival, circulating tumor cell number, seeding of cancer cells in distant organs, and metastasis formation. Transcriptionally, loss of E-cad was associated with upregulation of TGFβ, reactive oxygen, and apoptosis signaling pathways. At the cellular level, disseminating E-cad-negative cells exhibited nuclear enrichment of SMAD2/3, oxidative stress, and elevated apoptosis rates. Colony formation of E-cad-negative cells was rescued by inhibition of TGFβ receptor signaling, reactive oxygen accumulation, or apoptosis. Our results reveal that E-cad acts as a survival factor in IDC during the detachment, systemic dissemination, and seeding phases of metastasis by limiting reactive oxygen-mediated apoptosis. Identifying molecular strategies to inhibit E-cad mediated survival in metastatic breast cancer cells could potentially be a new therapeutic approach for breast cancer.

The clinicopathologic significance of extranodal tumor extension in locally advanced (pT3) colorectal adenocarcinoma and its association with the loss of E-cadherin expression

We investigated the clinicopathologic significance of extranodal tumor extension (ENTE) in locally advanced and prognostically inhomogeneous pT3 (pathologic T3) colorectal adenocarcinomas with regional lymph node metastasis. ENTE is defined as an interruption of the nodal capsule by tumor cells with extranodal growth. ENTE was observed in 46.3% of pT3 colorectal adenocarcinomas and was significantly associated with vascular invasion (P = 0.037, chi-square test), tumor deposit (P = 0.004, chi-square test) and high pN (pathologic N) stage (P = 0.002, chi-square test). An immunohistochemical study revealed that the loss of E-cadherin was significantly associated with ENTE (OR, 2.265; 95% CI, 1.008-5.086; P = 0.048). Kaplan-Meier survival analyses showed a significant difference between ENTE (+) and ENTE (-) groups for both cancer-specific survival (CSS) and recurrence-free survival (RFS) (P = 0.004 and P = 0.020, respectively, log-rank test). In the pN1a (single lymph node metastasis) subgroup, CSS and RFS were significantly shorter in patients with ENTE (P = 0.001 and P < 0.001, respectively, log-rank test). Comparing CSS and RFS according to pN stages and ENTE status, the survival curves of the pN1 group with ENTE were similar to those of the pN2 group without ENTE. ENTE is a useful prognostic factor for pT3 colorectal adenocarcinomas with regional lymph node metastasis, especially depending on the pN stages. The loss of E-cadherin expression may be an indicator of ENTE. Therefore, ENTE in colorectal adenocarcinoma should be considered in pN staging systems in the future.

Associations of CDH1 germline variant location and cancer phenotype in families with hereditary diffuse gastric cancer (HDGC)

INTRODUCTION

Hereditary diffuse gastric cancer (HDGC) is a cancer syndrome associated with variants in E-cadherin (CDH1), diffuse gastric cancer and lobular breast cancer. There is considerable heterogeneity in its clinical manifestations. This study aimed to determine associations between CDH1 germline variant status and clinical phenotypes of HDGC.

METHODS

One hundred and fifty-two HDGC families, including six previously unreported families, were identified. CDH1 gene-specific guidelines released by the Clinical Genome Resource (ClinGen) CDH1 Variant Curation Expert Panel were applied for pathogenicity classification of truncating, missense and splice site CDH1 germline variants. We evaluated ORs between location of truncating variants of CDH1 and incidence of colorectal cancer, breast cancer and cancer at young age (gastric cancer at <40 or breast cancer <50 years of age).

RESULTS

Frequency of truncating germline CDH1 variants varied across functional domains of the E-cadherin receptor gene and was highest in linker (0.05785 counts/base pair; p=0.0111) and PRE regions (0.10000; p=0.0059). Families with truncating CDH1 germline variants located in the PRE-PRO region were six times more likely to have family members affected by colorectal cancer (OR 6.20, 95% CI 1.79 to 21.48; p=0.004) compared with germline variants in other regions. Variants in the intracellular E-cadherin region were protective for cancer at young age (OR 0.2, 95% CI 0.06 to 0.64; p=0.0071) and in the linker regions for breast cancer (OR 0.35, 95% CI 0.12 to 0.99; p=0.0493). Different CDH1 genotypes were associated with different intracellular signalling activation levels including different p-ERK, p-mTOR and β-catenin levels in early submucosal T1a lesions of HDGC families with different CDH1 variants.

CONCLUSION

Type and location of CDH1 germline variants may help to identify families at increased risk for concomitant cancers that might benefit from individualised surveillance and intervention strategies.

Identification of prognostic molecular biomarkers in 157 HPV-positive and HPV-negative squamous cell carcinomas of the oropharynx

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) has been increasing due to high-risk HPV infection. We explored the significance of genetic alterations in HPV-positive (HPV-P) and HPV-negative (HPV-N) OPSCC patients on long-term outcome. A total of 157 cases of primary resected OPSCC diagnosed from 1978 to 2005 were subjected to a targeted exome sequencing by MSK-IMPACT™ interrogating somatic mutations in 410 cancer-related genes. Mutational profiles were correlated to recurrence and survival outcomes. OPSCC included 47% HPV-positive (HPV-P) and 53% HPV-negative (HPV-N) tumors arising in the base of tongue (BOT, 43%), palatine tonsil (30%) and soft palate (SP, 27%). HPV negative status, SP location and smoking were associated with poorer outcome. Poorer overall survival was found in NOTCH1-mutated HPV-P (p = 0.039), and in SOX2-amplified HPV-N cases (p = 0.036). Chromosomal arm gains in 8p and 8q, and 16q loss were more common in HPV-P (p = 0.005, 0.04 and 0.01, respectively), while 9p, 18q and 21q losses were more frequent in HPV-N OPSCC (p = 0.006, 0.002 and 0.01, respectively). Novel, potentially functional JAK3, MYC and EP300 intragenic deletions were found in HPV-P, and FOXP1, CDKN2A, CCND1 and RUNX1 intragenic deletions and one FGFR3 inversion were detected in HPV-N tumors. HPV-N/TP53-wild-type OPSCC harbored recurrent mutations in NOTCH1/3/4 (39%), PIK3CA, FAT1 and TERT. In comparison to their oral and laryngeal counterparts, HPV-N OPSCC were genetically distinct. In OPSCC, HPV status, tumor subsite and smoking determine outcome. Risk-stratification can be further refined based on the mutational signature, namely, NOTCH1 and SOX2 mutation status.

Heart myxoma develops oncogenic and metastatic phenotype

PURPOSE

Heart myxomas have been frequently considered as benign lesions associated with Carney's complex. However, after surgical removal, myxomas re-emerge causing dysfunctional heart.

METHODS

To identify whether cardiac myxomas may develop a metastatic phenotype as occurs in malignant cancers, a profile of several proteins involved in malignancy such as oncogenes (c-MYC, K-RAS and H-RAS), cancer-associated metabolic transcriptional factors (HIF-1α, p53 and PPAR-γ) and epithelial-mesenchymal transition proteins (fibronectin, vimentin, β-catenin, SNAIL and MMP-9) were evaluated in seven samples from a cohort of patients with atrial and ventricular myxomas. The analysis was also performed in: (1) cardiac tissue surrounding the area where myxoma was removed; (2) non-cancer heart tissue (NCHT); and (3) malignant triple negative breast cancer biopsies for comparative purposes.

RESULTS

Statistical analysis applying univariate (Kruskal-Wallis and Dunn's tests) and multivariate analyses (PCA, principal component analysis) revealed that heart myxomas (7-15 times) and myxoma surrounding tissue (22-99 times) vs. NCHT showed high content of c-MYC, p53, vimentin, and HIF-1α, indicating that both myxoma and its surrounding area express oncogenes and malignancy-related proteins as occurs in triple negative breast cancer.

CONCLUSIONS

Based on ROC (receiver operating characteristics) statistical analysis, c-MYC, HIF-1α, p53, and vimentin may be considered potential biomarkers for malignancy detection in myxoma.

Role of β-Catenin Activation Levels and Fluctuations in Controlling Cell Fate

Cells have developed numerous adaptation mechanisms to external cues by controlling signaling-pathway activity, both qualitatively and quantitatively. The Wnt/β-catenin pathway is a highly conserved signaling pathway involved in many biological processes, including cell proliferation, differentiation, somatic cell reprogramming, development, and cancer. The activity of the Wnt/β-catenin pathway and the temporal dynamics of its effector β-catenin are tightly controlled by complex regulations. The latter encompass feedback loops within the pathway (e.g., a negative feedback loop involving Axin2, a β-catenin transcriptional target) and crosstalk interactions with other signaling pathways. Here, we provide a review shedding light on the coupling between Wnt/β-catenin activation levels and fluctuations across processes and cellular systems; in particular, we focus on development, in vitro pluripotency maintenance, and cancer. Possible mechanisms originating Wnt/β-catenin dynamic behaviors and consequently driving different cellular responses are also reviewed, and new avenues for future research are suggested.

E-cadherin and NEDD9 expression in primary colorectal cancer, metastatic lymph nodes and liver metastases

In Croatia, colorectal cancer mortality rates in males are the third highest in Europe, after Hungary and Slovakia. The results for females rank Croatia in second place after Hungary. According to previous studies, the loss of E-cadherin expression and the higher expression of neural precursor cell-expressed developmentally downregulated 9 (NEDD9) are associated with a worse prognosis. The aim of the present study was to analyze the immunohistochemical expression of NEDD9 and E-cadherin as markers of metastatic potential using a tissue microarray. This retrospective study included 40 previously untreated patients, including 23 males and 17 females with a median age of 64.5 years (range 38–84), with colorectal cancer and synchronous liver metastases that underwent simultaneous colorectal and hepatic resection between January 1st 2006 and December 31st 2013, in the Clinical Hospital Center Sestre Milosrdnice (Zagreb, Croatia). The most frequent tumor stage was T3, while the most frequent nodal stage was N1. Microvascular invasion was present in 37.5% of patients, while perineural invasion was observed in 30% of patients. The immunohistochemical staining index of E-cadherin was highly positive in 87.5% samples of colorectal cancer, 67.7% of lymph nodes and 77.5% of liver metastases. In the primary tumor, highly positive NEDD9 expression was identified in 22.5% of patients. In lymph nodes, it was identified in 35.5% of patients, while in the liver, it was identified in 30% of patients. Significant positive correlations were observed between the percentage of positive lymph nodes and the immunohistochemical staining index of E-cadherin (ρ=0.372; P=0.039) and NEDD9 (ρ=0.451; P=0.011) in lymph nodes. After the conclusion of the study, 55% of the patients succumbed. No significant differences in survival rates were identified regarding the expression of E-cadherin and NEDD9 in the primary tumor, metastatic lymph nodes and liver metastases. Due to the small sample size and the negative results obtained, further research is required to implement these parameters as prognostic factors.

Biology of Nodal Spread in Colon Cancer: Insights from Molecular and Genetic Studies

Colorectal cancer (CRC) lymph node metastases are common but their genetics and the mechanism whereby these metastases occur are not well understood. Here we present recent data regarding genetic heterogeneity in primary CRCs and their metastasis. In addition, we explain the different potential models describing the mechanisms of metastasis and the data supporting them. Multiple studies have also revealed a variety of prognostic molecular markers that are associated with lymph node metastasis in CRC. A better understanding of genetic heterogeneity and the mechanisms of metastasis is critical to predicting clinical response and resistance to targeted therapy.

Metformin and JQ1 synergistically inhibit obesity-activated thyroid cancer

Compelling epidemiological evidence shows a strong positive correlation of obesity with thyroid cancer. In vivo studies have provided molecular evidence that high-fat-diet-induced obesity promotes thyroid cancer progression by aberrantly activating leptin-JAK2-STAT3 signaling in a mouse model of thyroid cancer (Thrb^PV/PVPten^+/- mice). The Thrb^PV/PVPten^+/- mouse expresses a dominantly negative thyroid hormone receptor β (denoted as PV) and a deletion of one single allele of the Pten gene. The Thrb^PV/PVPten^+/- mouse spontaneously develops follicular thyroid cancer, which allows its use as a preclinical mouse model to test potential therapeutics. We recently showed that inhibition of STAT3 activity by a specific inhibitor markedly delays thyroid cancer progression in high-fat-diet-induced obese Thrb^PV/PVPten^+/- mice (HFD-Thrb^PV/PVPten^+/- mice). Further, metformin, a widely used antidiabetic drug, blocks invasion and metastasis, but not thyroid tumor growth in HFD-Thrb^PV/PVPten^+/- mice. To improve efficacy in reducing thyroid tumor growth, we treated HFD-Thrb^PV/PVPten^+/- with JQ1, a potent inhibitor of the activity of bromodomain and extraterminal domain (BET) and with metformin. We found that the combined treatment synergistically suppressed thyroid tumor growth by attenuating STAT3 and ERK signaling, resulting in decreased anti-apoptotic key regulators such as Mcl-1, Bcl-2 and survivin and increased pro-apoptotic regulators such as Bim, BAD and cleave caspase 3. Furthermore, combined treatment of JQ1 and metformin reduced cMyc protein levels to suppress vascular invasion, anaplasia and lung metastasis. These findings indicate that combined treatment is more effective than metformin alone and suggest a novel treatment modality for obesity-activated thyroid cancer.

Emerging paradigms in the treatment of liver metastases in colorectal cancer

Efforts to combat colorectal cancer have benefited from improved screening and surveillance, which facilitates early detection. The survival rate associated with diagnosis at stage I is approximately 90%. However, progress in improving survival in metastatic colorectal cancer (mCRC) has been minimal. This review focuses on mCRC with special emphasis on the molecular aspects of liver metastases, which is one of the most frequently involved organ site. Better molecular evidence is required to guide the decisions for surgical and other interventions used in the clinical management of mCRC. Results from different treatment modalities have exposed significant gaps in the existing paradigms of the mCRC management. Indeed there is a critical need to better understand molecular events and pathways that lead to colorectal cancer liver metastasis. Such a focused approach may help identify biomarkers and drug targets that can be useful in the clinical applications. With this focus, we provide an account of the molecular pathways involved in the spread of CRC to the liver. Specifically, the molecular changes at the DNA and RNA levels that are associated with liver metastases are discussed. Similarly, we describe relevant microRNAs that are identified as regulators of gene expression and can also serve as biomarkers. Conventionally applied biomarkers are not yet specific and sensitive enough to be relied in routine clinical decision making. Hence search for novel biomarkers is critically needed especially if these can be utilized using liquid biopsies. This review provides a comprehensive analysis of current molecular evidence along with potential future directions that could reshape the diagnostic and management paradigms and thus mitigate the devastating impact of colorectal cancer metastasis to the liver.

CHIP functions as an oncogene by promoting colorectal cancer metastasis via activation of MAPK and AKT signaling and suppression of E-cadherin

BACKGROUND

The carboxyl terminus of Hsc70-interacting protein (CHIP) is an E3 ubiquitin ligase that plays a controversial role in different cancers, either as a tumor suppressor or a tumor promoter. To date, the exact function and underlying mechanism of CHIP in colorectal cancer (CRC) is not yet clear. Here we aimed to determine whether CHIP could affect the biological behaviors of CRC cells and its underlying mechanisms.

METHODS

Stably transfected CHIP overexpression and depletion DLD-1 and HT-29 cells were established using Lipofectamine 2000. Cell growth was monitored by x-Celligence system. Cell proliferation was detected using CCK-8 and Brdu proliferation assay. Cell apoptosis and cell cycle were detected by flow cytometry analysis. Cell migration and invasion abilities were monitored by x-Celligence system, wound healing assay and transwell assay. In vivo intraperitoneal metastasis assay was performed to investigate the influence of CHIP on the tumor metastasis of CRC cells in nude mice. The expression of ERK, AKT, NF-кB signaling subunits and EMT related proteins were detected by Western blotting. The influence and function of CHIP on the protein expression of CRC cells were also elucidated by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. CRC microarray tissue was analyzed to investigate the CHIP expression and its clinical significance.

RESULTS

CHIP depletion inhibited cell growth, migration and invasion potential of CRC cells, accompanied by downregulation of MAPK and AKT signaling activities and upregulation of E-cadherin. CHIP overexpression dramatically enhanced the migration and invasion abilities, due to the upregulation of MAPK and AKT signaling and downregulation of E-cadherin. The proteomic analysis confirmed that E-cadherin was decreased in CHIP-overexpressing CRC cells. Furthermore, clinical tissue data revealed that CHIP expression was upregulated in CRC samples and was significantly correlated with poor survival of CRC patients. Mechanically, CHIP probably activated the MAPK and AKT signaling, which inactivated GSK-3β. The GSK-3β inactivation, in turn, upregulated Slug and led to E-cadherin downregulation and EMT initiation.

CONCLUSIONS

Our finding suggested that CHIP functions as an oncogene in the migration and metastasis of CRC, and is a potential unfavorable independent predictive biomarker for CRC. CHIP activates the AKT pathway to promote EMT and metastasis in CRC through the CHIP-MAPK/AKT-GSK-3β-Slug-E-cadherin pathways.

Cadherin Expression Shift Could Well Distinguish Esophageal Squamous Cell Carcinoma from Non- Cancerous Esophageal Tissues

BACKGROUND

Biomarkers for esophageal squamous cell carcinoma (ESCC) identification with high sensitivity are not well established. Since abnormal expression of cadherins has been widely reported in cancer, we explored its feasibility as an ESCC biomarker.

METHODS

Expression of E-cadherin and N-cadherin were detected in 150 esophageal tissues by immunohistochemistry. Staining strength and percentage in different subcellular structures of each specimen were evaluated by 2 independent pathologists. A logistic regression-based classifier derived from E-cadherin and N-cadherin staining was generated.

RESULTS

E-cadherin exhibited decreased membrane expression in ESCC, while N-cadherin exhibited decreased expression in the nucleus but elevated expression in the cytoplasm. Both E-cadherin and N-cadherin could distinguish ESCC tissues from non-cancerous tissues (area under the curve (AUC) = 0.748, 0.801, respectively). E-cadherin and N-cadherin staining scores could be merged into a cadherin (CDH) logistic index, which showed better discrimination (AUC = 0.909) than E-cadherin or N-cadherin alone. Further investigation indicated that the CDH logistic index was significantly correlated with tumor size and differentiation in ESCC.

CONCLUSION

Both E-cadherin and N-cadherin had a strong expression shift in ESCC compared with non-cancerous tissues. The CDH logistic index, a parameter integrating the expression data of both cadherins, could be used as a marker with high sensitivity and specificity in the identification of ESCC.

Colitic Cancer Develops Through Mutational Alteration Distinct from that in Sporadic Colorectal Cancer: A Comparative Analysis of Mutational Rates at Each Step

BACKGROUND

Patients with ulcerative colitis (UC) are at risk of UC-associated colorectal cancer (CRC); however, little is known about genetic alterations occurring during UC carcinogenesis. We examined mutational changes in patients with colitic cancer and the features that differed between the carcinogenesis of UC and sporadic CRC.

MATERIAL AND METHODS

Specimens were obtained from the non-neoplastic mucosa and cancer cells of 12 patients with colitic cancer. The mutational rate of oncogenes in colitic cancer was analyzed and compared to that of oncogenes in sporadic CRC.

RESULTS

We observed a lower mutation rate in adenomatous polyposis coli (APC) (16.7%(2/12) vs. 75.9%(161/212), respectively, p=0.0001) and KRAS (16.7%(2/12) vs. 42% (89/212), respectively, p=0.04) in colitic cancer than in sporadic CRC. With respect to cadherin 1 (CDH1) and fibroblast growth factor receptor 2 (FGFR2), the mutational rates for non-neoplastic colorectal mucosa were similar to those in sporadic CRC.

CONCLUSION

We demonstrated that mutational rates for APC and KRAS differ between colitic cancer and sporadic CRC. Furthermore, we revealed that CDH1 and FGFR2 become mutated at an earlier stage in colitic carcinogenesis than in sporadic CRC.

Epigenomic biomarkers for prognostication and diagnosis of gastrointestinal cancers

Altered epigenetic regulation is central to many human diseases, including cancer. Over the past two decade, major advances have been made in our understanding of the role of epigenetic alterations in carcinogenesis, particularly for DNA methylation, histone modifications and non-coding RNAs. Aberrant hypermethylation of DNA at CpG islands is a well-established phenomenon that mediates transcriptional silencing of tumor suppressor genes, and it is an early event integral to gastrointestinal cancer development. As such, detection of aberrant DNA methylation is being developed as biomarkers for prognostic and diagnostic purposes in gastrointestinal cancers. Diverse tissue types are suitable for the analyses of methylated DNA, such as tumor tissues, blood, plasma, and stool, and some of these markers are already utilized in the clinical setting. Recent advances in the genome-wide epigenomic approaches are enabling the comprehensive mapping of the cancer methylome, thus providing new avenues for mining novel biomarkers for disease prognosis and diagnosis. Here, we review the current knowledge on DNA methylation biomarkers for the prognostication and non-invasive diagnosis of gastrointestinal cancers and highlight their clinical application.

Predictive value of gene methylation for second recurrence following surgical treatment of first bladder recurrence of a primary upper-tract urothelial carcinoma

The clinical relevance of aberrant DNA promoter methylation is being increasingly recognized in urothelial carcinoma. The present study was conducted to explore the methylation status of patients with upper-tract urothelial carcinoma (UTUC) who experienced bladder recurrence, and to evaluate the predictive value of gene methylation for second bladder recurrence and tumor progression. A total of 85 patients with primary UTUC, who experienced bladder recurrence after radical nephroureterectomy, were enrolled between January 2001 and December 2013. Using methylation-sensitive polymerase chain reaction, the promoter methylation statuses of 10 genes were analyzed in the bladder tumor specimens. Among the patient group, 32 patients experienced second bladder recurrence, and bladder progression was detected in 16. With the exception of BRCA1, the methylation rate of the majority of genes tended to gradually increase to varying extents with the number of recurrences; a smaller proportion of primary tumors exhibited gene methylation when compared with the first recurrent tumors and second recurrent tumors. Univariate and multivariate Cox regression analyses revealed that unmethylated GDF15 [hazard ratio (HR)=0.36; 95% confidence interval (CI), 0.14-0.92] and methylated VIM (HR=2.91; 95% CI, 1.11-7.61) in the first recurrent bladder tumor, as well as male gender (HR=2.28; 95% CI, 1.06-4.87), first recurrence interval <8 months (HR=2.34; 95% CI, 1.15-4.78) and primary UTUC tumor size ≥5 cm (HR=3.48; 95% CI, 1.43-8.45) were independent risk factors for a second bladder recurrence after surgery for the first bladder recurrence; the Harrell's concordance index (c-index) for the related nomogram was 0.71 (95% CI: 0.61-0.81). Furthermore, methylated CDH1 (HR=2.91; 95% CI, 1.08-7.77) and VIM (HR=4.91; 95% CI, 1.11-21.7) in the first recurrent bladder tumor, male gender (HR=3.6; 95% CI, 1.1-11.73), and primary tumor stage T2-T4 (HR=4.57; 95% CI, 1.22-17.13), multifocality (HR=3.64; 95% CI, 1.19-11.16) and size ≥5 cm (HR=3.1; 95% CI, 1.91-10.54) for the primary UTUC were considered to be predictors of tumor progression; the c-index for the nomogram was 0.88 (95% CI, 0.69-0.92). The present findings demonstrated that promoter methylation of cancer-related genes was frequently observed in patients with urothelial carcinoma, and that the gene methylation rate of certain genes tended to gradually increase with the number of bladder recurrences. This may be used as a predictive factor for a second bladder recurrence and tumor progression after the surgical treatment of the first bladder recurrence.

Long noncoding RNA VIM-AS1 promotes colorectal cancer progression and metastasis by inducing EMT

Emerging evidence indicates that lncRNAs play crucial roles in the initiation and progression of various malignant tumors. VIM-AS1 RNA is an lncRNA that transcribes from a shared bidirectional promoter with vimentin mRNA and its function in cancer cells is largely unknown. This study assessed the clinical significance of VIM-AS1 expression in colorectal cancer (CRC). We found that the VIM-AS1 transcript was significantly upregulated in high-grade, lymph node metastasis and vascular invasion tumors. Loss-of-function experiments revealed that the downregulation of VIM-AS1 could inhibit tumor cell proliferation by inducing apoptosis, cellular senescence and arresting the cell cycle. Moreover, the obtained data demonstrated that VIM-AS1 might play a crucial role in cell migration as well as the epithelial to mesenchymal transition (EMT) of CRC cells. Collectively, for the first time, our data provide novel evidence for the biological and clinical significance of VIM-AS1 expression in CRC. Further, the findings of this study suggest that VIM-AS1 promotes tumor growth and metastasis by inducing EMT in CRC cells and could be considered as a novel tumor marker with probable value in diagnosis and CRC treatment.

Decoding colorectal cancer epigenomics

Colorectal cancer (CRC) is very heterogeneous and presents different types of epigenetic alterations including DNA methylation, histone modifications and microRNAs. These changes are considered as characteristics of various observed clinical phenotypes. Undoubtedly, the discovery of epigenetic pathways with novel epigenetic-related mechanisms constitutes a promising advance in cancer biomarker discovery. In this review, we provide an evidence-based discussing of the current understanding of CRC epigenomics and its role in initiation, epithelial-to-mesenchymal transition and metastasis. We also discuss the recent findings regarding the potential clinical perspectives of these alterations as potent biomarkers for CRC diagnosis, prognosis, and therapy in the era of liquid biopsy.

Promoter hypermethylation may contribute to E‑cadherin repression in the human salivary carcinoma ex pleomorphic adenoma

The role of promoter methylation in the inactivation of E‑cadherin (CDH1) in salivary carcinoma ex pleomorphic adenoma (CXPA) is unknown. The objective of this study was to determine the role and potential clinical implications of CDH1 promoter methylation in salivary CXPA. The CDH1 promoter methylation status was determined by bisulfite sequencing PCR in 37 primary CXPA tissues and 2 CXPA cell lines. E‑cadherin expression levels were determined by immunohistochemical analysis of each tumor. E‑cadherin protein levels and CDH1 mRNA levels were examined by immunoblotting and quantitative real-time PCR, respectively, in 2 CXPA cell lines. Cells were treated with 5‑Aza-dC or TGF‑β1 to test the influence of promoter methylation on CDH1 mRNA and protein expression. Associations between CDH1 molecular alterations and patients' clinicopathologic characteristics and prognosis were statistically evaluated. CDH1 promoter hypermethylation was detected in 21 of 37 tumors (56.76%). Of these 37 tumors, 13 tumors (35.14%) showed low E‑cadherin expression. Tumors that had CDH1 promoter methylation had a histological tendency toward luminal differentiation (P=0.004), high tumor grade (P=0.005), high T stage (P=0.024) and high TNM stage (P=0.038) compared with tumors that did not. The two CXPA cell lines exhibited an inverse relationship between CDH1 promoter methylation status and CDH1 mRNA and protein expression. Treatment of the hypermethylated cell line with 5‑Aza-dC restored CDH1 mRNA and E‑cadherin protein expression. The induction of hypermethylation by TGF‑β1 resulted in the repression of CDH1 mRNA and protein expression. CDH1 is commonly silenced in CXPA through promoter methylation. CDH1 methylation is closely related to tumor cell differentiation, histological grade, lymph node metastasis and advanced TNM stage, indicating that CDH1 methylation may play a role in the initiation and progression of CXPA.

E-cadherin: Its dysregulation in carcinogenesis and clinical implications

E-cadherin is a transmembrane glycoprotein which connects epithelial cells together at adherens junctions. In normal cells, E-cadherin exerts its tumour suppressing role mainly by sequestering β-catenin from its binding to LEF (Lymphoid enhancer factor)/TCF (T cell factor) which serves the function of transcribing genes of the proliferative Wnt signaling pathway. Despite the ongoing debate on whether the loss of E-cadherin is the cause or effect of epithelial-mesenchymal transition (EMT), E-cadherin functional loss has frequently been associated with poor prognosis and survival in patients of various cancers. The dysregulation of E-cadherin expression that leads to carcinogenesis happens mostly at the epigenetic level but there are cases of genetic alterations as well. E-cadherin expression has been linked to the cellular functions of invasiveness reduction, growth inhibition, apoptosis, cell cycle arrest and differentiation. Studies on various cancers have shown that these different cellular functions are also interdependent. Recent studies have reported a rapid expansion of E-cadherin clinical relevance in various cancers. This review article summarises the multifaceted effect E-cadherin expression has on cellular functions in the context of carcinogenesis as well as its clinical implications in diagnosis, prognosis and therapeutics.