Breast cancer susceptibility risk associations and heterogeneity by E-cadherin tumor tissue expression

miR614 Expression Enhances Breast Cancer Cell Motility

Using a data driven analysis of a high-content screen, we have uncovered new regulators of epithelial-to-mesenchymal transition (EMT) induced cell migration. Our results suggest that increased expression of miR614 can alter cell intrinsic gene expression to enhance single cell and collective migration in multiple contexts. Interestingly, miR614 specifically increased the expression of the EMT transcription factor Slug while not altering existing epithelial character or inducing other canonical EMT regulatory factors. Analysis of two different cell lines identified a set of genes whose expression is altered by the miR614 through direct and indirect mechanisms. Prioritization driven by functional testing of 25 of the miR614 suppressed genes uncovered the mitochondrial small GTPase Miro1 and the transmembrane protein TAPT1 as miR614 suppressed genes that inhibit migration. Notably, the suppression of either Miro1 or TAPT1 was sufficient to increase Slug expression and the rate of cell migration. Importantly, reduced TAPT1 expression correlated with an increased risk of relapse in breast cancer patients. Together, our results reveal how increased miR614 expression and the suppression of TAPT1 and Miro1 modulate the EMT state and migratory properties of breast cancer cells.

Breast cancer models: Engineering the tumor microenvironment

The mechanisms behind cancer initiation and progression are not clear. Therefore, development of clinically relevant models to study cancer biology and drug response in tumors is essential. In vivo models are very valuable tools for studying cancer biology and for testing drugs; however, they often suffer from not accurately representing the clinical scenario because they lack either human cells or a functional immune system. On the other hand, two-dimensional (2D) in vitro models lack the three-dimensional (3D) network of cells and extracellular matrix (ECM) and thus do not represent the tumor microenvironment (TME). As an alternative approach, 3D models have started to gain more attention, as such models offer a platform with the ability to study cell-cell and cell-material interactions parametrically, and possibly include all the components present in the TME. Here, we first give an overview of the breast cancer TME, and then discuss the current state of the pre-clinical breast cancer models, with a focus on the engineered 3D tissue models. We also highlight two engineering approaches that we think are promising in constructing models representative of human tumors: 3D printing and microfluidics. In addition to giving basic information about the TME in the breast tissue, this review article presents the state-of-the-art tissue engineered breast cancer models. STATEMENT OF SIGNIFICANCE: Involvement of biomaterials and tissue engineering fields in cancer research enables realistic mimicry of the cell-cell and cell-extracellular matrix (ECM) interactions in the tumor microenvironment (TME), and thus creation of better models that reflect the tumor response against drugs. Engineering the 3D in vitro models also requires a good understanding of the TME. Here, an overview of the breast cancer TME is given, and the current state of the pre-clinical breast cancer models, with a focus on the engineered 3D tissue models is discussed. This review article is useful not only for biomaterials scientists aiming to engineer 3D in vitro TME models, but also for cancer researchers willing to use these models for studying cancer biology and drug testing.

EMT-related protein expression in polyploid giant cancer cells and their daughter cells with different passages after triptolide treatment

Our previous work has demonstrated that paclitaxel can induce the formation of polyploid giant cancer cells (PGCCs) and inhibit tumor growth by reprogramming ovarian cancer epithelial cells to a benign fibroblastic state via epithelial-mesenchymal transition. Here, triptolide (TPL) was used to treat the breast and ovarian cancer lines. The morphologic characteristics and EMT-related protein expression were studied in different generation of cancer cells after TPL treatment. When BT-549 and HEY cells reached 80-90% confluence, TPL was added to BT-549 for 48 h and HEY for 9 h at a concentration of 40 ng/ml. Scattered PGCCs survived from TPL treatment and generated daughter cells, and then were cultured in medium without TPL for at least ten generation. Western blot analysis and immunocytochemical staining were performed to detect the expression levels and subcellular location of EMT-related proteins in control cells and different generation of TPL-induced PGCCs with daughter cells. Furthermore, wound-healing, transwell, cell counting kit-8, and MTT assay were used to compare the alternation of migration, invasion, and proliferation among control cells and different generation of TPL-induced PGCCs with daughter cells. Scattered PGCCs survived from the treatment of TPL and produced small-sized daughter cells 20-30 days after treatment. Compared to the control cells, the first generation of TPL-induced PGCCs with their daughter cells differentially expressed EMT-related proteins including fibronectin, E-cadherin, vimentin, and Twist, and had lower migration, invasion, and proliferation abilities. The abilities of migration, invasion, and proliferation of TPL-induced PGCCs with their daughter cells gradually enhanced as the passages increasing, and markedly exceeded the control cells in the tenth generation. TPL-induced PGCCs with their daughter cells gradually obtain the abilities of invasion and metastasis in vitro as the number of passage increasing, which can be used to mimick the cancer cells subjected to anti-cancer drugs in vivo and may provide some new insights to explore the mechanism of cancer invasion, metastasis and relapse after chemotherapy.

E-cadherin expression is associated with susceptibility and clinicopathological characteristics of thyroid cancer: A PRISMA-compliant meta-analysis

BACKGROUND

Recently, many studies have been carried out to investigate the clinicopathological significance of E-cadherin expression in thyroid cancer. However, the results remained inconsistent. In the present study, we performed a meta-analysis to evaluate the associations of E-cadherin expression with susceptibility and clinicopathological characteristics of thyroid cancer.

METHODS

Eligible studies were searched from Medicine, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and Wanfang databases. The strength of associations between E-cadherin expression and susceptibility and clinicopathological features of thyroid cancer were assessed by pooled odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Forty-six studies with 1700 controls and 2298 thyroid cancer patients were included for this meta-analysis. Pooled results indicated that E-cadherin expression was significantly associated with susceptibility of papillary cancer and follicular cancer (papillary cancer, ORs = 14.31, 95% CIs = 3.42-59.90; follicular cancer, ORs = 10.14, 95% CI = 4.52-22.75). Significant association between E-cadherin expression and thyroid cancer risk was also observed in the subgroup analysis based on control group (normal thyroid tissue, ORs = 28.28, 95% CI = 8.36-95.63; adjacent thyroid tissue, ORs = 8.83, 95% CI = 3.27-23.85; benign thyroid tissue, ORs = 43.96, 95% CI = 9.91-194.95). In addition, E-cadherin expression was significantly correlated with lymph node metastasis, differentiation, and tumor-node-metastasis (TNM) stage of thyroid cancer (lymph node metastasis, ORs = 3.21, 95% CI = 1.98-5.20; differentiation, ORs = 0.25, 95% CI = 0.07-0.82; TNM stage, ORs = 4.85, 95% CI = 2.86-8.25).

CONCLUSIONS

The present study showed that E-cadherin expression was significantly associated with susceptibility and clinicopathological characteristics of thyroid cancer, which suggested that E-cadherin expression might be a potential predictive factor for clinical progression of thyroid cancer.

Implications of soluble E-cadherin level of antiviral treatment in patients with chronic hepatitis C virus infection

BACKGROUND AND AIMS

Soluble E-cadherin (sE-cadherin) has been observed elevated in patients with various diseases, and implicated in the occurrence and development of those diseases. The implications of sE-cadherin in chronic hepatitis C virus (HCV) infection are still unclear. The purpose of this study is to explore the significance of sE-cadherin in chronic hepatitis C infection and the correlation with treatment response.

METHODS

87 chronic HCV infected patients and 60 healthy subjects were enrolled in this study. Blood samples from patients receiving the combined treatment of pegylated interferon-a (Peg-IFN-α) with ribavirin (RBV) were collected before treatment, during 4th, 12th therapy weeks, end of the treatment, and 24 weeks post-therapy. Plasma sE-cadherin level was detected by enzyme-linked immunosorbent assay (ELISA) and the relationship between sE-cadherin and antiviral treatment outcome was analyzed.

RESULTS

Plasma sE-cadherin concentrations of Chronic HCV infected patients were significantly higher than that of healthy controls. A strong correlation between sE-cadherin level and the HCV viral load, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and also glutamyl transpeptidase (GGT) level was detected. Chronic HCV infected patients achieving rapid virological response (RVR) and sustained virological response (SVR) had lower baseline sE-cadherin concentrations compared with the non-RVR and non-SVR groups respectively. Univariate and multivariate regression analyses suggested that baseline plasma sE-cadherin level was predictive of therapeutic effect in patients with chronic HCV infection.

CONCLUSION

Baseline sE-cadherin level could be considered as an independent predictor of SVR with Peg-IFN-α plus ribavirin therapy in the Chinese Han population chronic HCV infection patients. Effective antiviral therapy might restore sE-cadherin at physiological levels.

Control of Invasion by Epithelial-to-Mesenchymal Transition Programs during Metastasis

Epithelial-to-mesenchymal transition (EMT) programs contribute to the acquisition of invasive properties that are essential for metastasis. It is well established that EMT programs alter cell state and promote invasive behavior. This review discusses how rather than following one specific program, EMT states are diverse in their regulation and invasive properties. Analysis across a spectrum of models using a combination of approaches has revealed how unique features of distinct EMT programs dictate whether tumor cells invade as single cells or collectively as cohesive groups of cells. It has also been shown that the mode of collective invasion is determined by the nature of the EMT, with cells in a trailblazer-type EMT state being capable of initiating collective invasion, whereas cells that have undergone an opportunist-type EMT are dependent on extrinsic factors to invade. In addition to altering cell intrinsic properties, EMT programs can influence invasion through non-cell autonomous mechanisms. Analysis of tumor subpopulations has demonstrated how EMT-induced cells can drive the invasion of sibling epithelial populations through paracrine signaling and remodeling of the microenvironment. Importantly, the variation in invasive properties controlled by EMT programs influences the kinetics and location of metastasis.

Expression and clinical significance of SNAI1 and ZEB1 genes in acute myeloid leukemia patients

Acute myeloid leukemia (AML) is the most common type of acute leukemia in adults, it represents nearly 32% of all new cases of leukemia. This study aimed to evaluate the SNAI1 and ZEB1 genes expression in AML patients and determine their diagnostic and prognostic significance. We determined the expression of SNAI1 and ZEB1 genes and serum E-cadherin levels in early diagnosed patients with AML. Sixty early diagnosed AML patients and 20 healthy subjects were enrolled in this study, SNAI1 and ZEB1 genes expression was determined by Real-time PCR while E-Cadherin serum levels were determined by ELISA. The results of this study demonstrated that, all AML patients positively expressed the SNAI1 gene with fold change 2.6. While, the ZEB1 expression was positive in 56.7% of the patients with fold change 1.8. SNAI1 and ZEB1 genes were highly expressed in M5 subtype (FC = 13.8 and 9.3, respectively). On the other hand, serum E-cadherin concentrations of the AML patients showed decrease when compared with those of the control but the decrease was not reach to the significance level. The findings of this study suggest inclusion of SNAI1 and ZEB1 genes expression in the cluster of potential genetic biomarkers to be studied in AML cases as diagnostic and prognostic markers.

E-cadherin breast tumor expression, risk factors and survival: Pooled analysis of 5,933 cases from 12 studies in the Breast Cancer Association Consortium

E-cadherin (CDH1) is a putative tumor suppressor gene implicated in breast carcinogenesis. Yet, whether risk factors or survival differ by E-cadherin tumor expression is unclear. We evaluated E-cadherin tumor immunohistochemistry expression using tissue microarrays of 5,933 female invasive breast cancers from 12 studies from the Breast Cancer Consortium. H-scores were calculated and case-case odds ratios (OR) and 95% confidence intervals (CIs) were estimated using logistic regression. Survival analyses were performed using Cox regression models. All analyses were stratified by estrogen receptor (ER) status and histologic subtype. E-cadherin low cases (N = 1191, 20%) were more frequently of lobular histology, low grade, >2 cm, and HER2-negative. Loss of E-cadherin expression (score < 100) was associated with menopausal hormone use among ER-positive tumors (ever compared to never users, OR = 1.24, 95% CI = 0.97-1.59), which was stronger when we evaluated complete loss of E-cadherin (i.e. H-score = 0), OR = 1.57, 95% CI = 1.06-2.33. Breast cancer specific mortality was unrelated to E-cadherin expression in multivariable models. E-cadherin low expression is associated with lobular histology, tumor characteristics and menopausal hormone use, with no evidence of an association with breast cancer specific survival. These data support loss of E-cadherin expression as an important marker of tumor subtypes.

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.

Fine-Mapping of the 1p11.2 Breast Cancer Susceptibility Locus

The Cancer Genetic Markers of Susceptibility genome-wide association study (GWAS) originally identified a single nucleotide polymorphism (SNP) rs11249433 at 1p11.2 associated with breast cancer risk. To fine-map this locus, we genotyped 92 SNPs in a 900kb region (120,505,799-121,481,132) flanking rs11249433 in 45,276 breast cancer cases and 48,998 controls of European, Asian and African ancestry from 50 studies in the Breast Cancer Association Consortium. Genotyping was done using iCOGS, a custom-built array. Due to the complicated nature of the region on chr1p11.2: 120,300,000-120,505,798, that lies near the centromere and contains seven duplicated genomic segments, we restricted analyses to 429 SNPs excluding the duplicated regions (42 genotyped and 387 imputed). Per-allelic associations with breast cancer risk were estimated using logistic regression models adjusting for study and ancestry-specific principal components. The strongest association observed was with the original identified index SNP rs11249433 (minor allele frequency (MAF) 0.402; per-allele odds ratio (OR) = 1.10, 95% confidence interval (CI) 1.08-1.13, P = 1.49 x 10-21). The association for rs11249433 was limited to ER-positive breast cancers (test for heterogeneity P≤8.41 x 10-5). Additional analyses by other tumor characteristics showed stronger associations with moderately/well differentiated tumors and tumors of lobular histology. Although no significant eQTL associations were observed, in silico analyses showed that rs11249433 was located in a region that is likely a weak enhancer/promoter. Fine-mapping analysis of the 1p11.2 breast cancer susceptibility locus confirms this region to be limited to risk to cancers that are ER-positive.

CDH1 promoter methylation correlates with decreased gene expression and poor prognosis in patients with breast cancer

The E-cadherin gene (CDH1) is associated with poor prognosis and metastasis in patients with breast cancer, and methylation of its promoter is correlated with decreased gene expression. However, there is currently no direct evidence that CDH1 promoter methylation indicates poor prognosis in patients with breast cancer. In the present study, methylation-specific polymerase chain reaction (PCR) was applied to detect the methylation status of the CDH1 promoter in 137 primary breast cancer, 85 matched normal breast tissue and 13 lung metastasis specimens. Reverse transcription-quantitative PCR was used to assess the relative expression levels of CDH1 mRNA, and correlation analysis between CDH1 methylation status, and gene expression, clinicopathological characteristics and patient survival was performed. Methylation of CDH1 was identified in 40.9% (56/137) of primary breast cancer specimens, 61.5% (8/13) of lung metastasis specimens and none of the matched normal breast specimens. The downregulation of CDH1 mRNA and E-cadherin protein expression were identified to be significantly correlated with CDH1 methylation (P<0.05). In addition, CDH1 methylation was significantly associated with lymph node metastasis and estrogen receptor status of patients (P<0.05). In univariate analyses, patients with CDH1 methylation exhibited poor overall survival (OS) and disease-free survival (DFS; P<0.05). Furthermore, multivariate analyses revealed that CDH1 methylation was an independent prognostic factor predicting poor OS (HR, 1.737; 95% CI, 0.957-3.766; P=0.041) and DFS (HR, 2.018; 95% CI, 2.057-3.845; P=0.033) in patients with breast cancer. Therefore, the present study suggests that CDH1 promoter methylation may be correlated with breast carcinogenesis and indicates poor prognosis in patients with breast cancer.

Decline in Antigenicity of Tumor Markers by Storage Time Using Pathology Sections Cut From Tissue Microarrays

Sectioning a whole tissue microarrray (TMA block) and storing the sections maximizes the number of sections obtained, but may impair the antigenicity of the stored sections. We have investigated the impact of TMA section storage on antigenicity. First, we reexamined existing TMA data to determine whether antigenicity in stored sections changes over time. Component scores for each marker, based on cellular compartment of staining and score-type, were evaluated separately. Residual components scores adjusted for grade, tumor size, and node positivity, were regressed on the number of days storage to evaluate the effect of storage time. Storage time ranged from 2 to 1897 days, and the mean change in antigenicity per year ranged from -0.88 (95% confidence interval, -1.11 to -0.65) to 0.035 (95% confidence interval, 0.016-0.054). Further analysis showed no significant improvement in the fit of survival models if storage time adjusted scores were included in the models rather than unadjusted scores. We then compared 3 ways of processing TMA sections after cutting-immediate staining, staining after 1 year, and staining after 1 year coated in wax-on the immunohistochemistry results for: progesterone receptor, a routinely used, robust antibody, and MKI67, which is generally considered less robust. The progesterone receptor scores for stored sections were similar to those for unstored sections, whereas the MKI67 scores for stored sections were substantially different to those for unstored sections. Wax coating made little difference to the results. Biomarker antigenicity shows a small decline over time that is unlikely to have an important effect on studies of prognostic biomarkers.

Expression of E-cadherin in oral lichen planus

Oral lichen planus (OLP) is a common lesion of the oral mucosa that can progress to cancer. E-cadherin is involved in intercellular adherence and the pathogenesis, development and metastasis of tumors, and is considered to be an important indicator of tumor progression and prognosis. The aim of this study was to investigate the expression of E-cadherin in OLP in order to elucidate its role in the pathogenesis and malignant transformation of OLP and provide evidence to support the early diagnosis and treatment of OLP with malignant potential. OLP specimens (n=52) and samples of normal oral mucosa (n=41) as the control were collected. Immunohistochemical staining was conducted to reveal the expression of E-cadherin in the OLP samples and normal oral mucosa. It was observed that 25 of the 52 OLP specimens exhibited normal positive expression of E-cadherin and 27 exhibited abnormal positive expression, corresponding to an abnormal positive rate of 51.92%. In the normal oral mucosa group, 39 of the 41 cases exhibited normal positive expression and 2 exhibited abnormal positive expression. The abnormal positive rate in the normal oral mucosa was 4.88%, which was significantly lower than that in the OLP group. The significantly elevated rate of abnormal positive expression of E-cadherin in the OLP group indicates the involvement of E-cadherin in the malignant transformation of OLP and supports the malignant potential of OLP.

Quantitative assessment of miR34a as an independent prognostic marker in breast cancer

Background:

Aberrant expression of microRNAs (miRNAs) is associated with cancer progression, initiation and metastasis. MiR34a is a miRNA that has been previously described as a tumour suppressor. Herein, we assess the expression of miR34a in three independent breast cancer cohorts using a quantitative in situ hybridisation assay (qISH) and determined its association with disease-specific death in breast cancer.

Methods:

The qISH method was applied to three independent primary breast cancer cohorts (Cohort 1 with 461, Cohort 2 with 279 and Cohort 3 with 795 patients) using 5′ and 3′ double DIG-labelled LNA-modified probe against miR34a using the protocol described previously. Level of expression measured as automated quantitative analysis (AQUA) score for miR34a was determined for each patient and assessed for association with risk of disease-specific death. An optimal cutpoint was determined using the X-tile software for disease-specific survival in Cohort 1 and this cutpoint was then applied to the other two cohorts after median normalisation of AQUA scores.

Results:

Loss of miR34a is associated with poor outcome in three independent breast cancer cohorts (uncorrected log-rank P=0.0188 for Cohort 1, log-rank P=0.0024 for Cohort 2 and log-rank P=0.0455 for Cohort 3). In all three cohorts, loss of miR34a is able to stratify patients with poor disease-specific survival among node-negative patients, but not in node-positive population. Multivariate Cox proportional hazards analysis in Cohort 1 (P=0.0381) and Cohort 2 (P=0.0468) revealed that loss of miR34a is associated with poor outcome, independent of age, node status, receptor status and tumour size.

Conclusion:

Loss of the tumour suppressor, miR34a, identifies a subgroup of breast cancer patients with poor disease-specific survival. This study is consistent with the well-established preclinical observations for miR34a as a tumour suppressor and suggests that miR34a may have future value as a biomarker in breast cancer.

C6ORF97-ESR1 breast cancer susceptibility locus: influence on progression and survival in breast cancer patients

Genome-wide association studies have identified a single-nucleotide polymorphism (SNP) to be associated with an increased risk of breast cancer. The biology of one of the susceptibility locus C6ORF-ESR1 and whether it also contributes to progression of established disease has not yet been ascertained. We examined the association of rs2046210 and its six linkage disequilibrium SNPs with clinicopathological characteristics, prognosis, and gene expression levels of ESR1 and the C6ORFs (C6ORF97:CCDC170, C6ORF211, C6ORF96:RMND1) in 344 breast cancer tissue samples and 253 corresponding samples of adjacent normal tissue. Tumor genotypes with homozygous risk alleles were more frequent than normal tissues. The tumor genotypes of rs2046210 and rs6929137 with homozygous risk alleles showed worse relapse-free survival (RFS, P=0.038 and P=0.031, respectively), whereas no notable associations were observed with either clinicopathological characteristics or expression of the peripheral genes. Higher C6ORF97 expression correlated with ER negativity (P<0.0001), highly proliferative characteristics (P=0.0005 for Ki67, P<0.0001 for nuclear grade) and worse RFS in the ER+/HER2- cohort (P=0.013), whereas the other two C6ORFs showed the inverse associations. Furthermore, C6ORF97 showed significant worse prognostic values especially in luminal B subtype in the publically available data sets. rs2046210 and the upstream gene C6ORF97 might have substantial roles not only in carcinogenesis but also in progression toward a more aggressive phenotype in breast cancer patients, which suggests that functional studies of this locus are imperative.

ERβ splice variant expression in four large cohorts of human breast cancer patient tumors

Though the role of Estrogen Receptor (ER)α in breast cancer has been studied extensively, there is little consensus about the role of alternative ER isoform ERβ in breast cancer biology. ERβ has significant sequence homology to ERα but is located on a different chromosome and maintains both overlapping and unique functional attributes. Five variants exist, resulting from alternative splicing of the C-terminal region of ERβ. The relevance of ERβ variants in breast cancer outcomes and response to therapy is difficult to assess because of conflicting reports in the literature, likely due to variable methods used to assess ERβ in patient tumors. Here, we quantitatively assess expression of ERβ splice variants on over 2,000 breast cancer patient samples. Antibodies against ERβ variants were validated for staining specificity in cell lines by siRNA knockdown of ESR2 and staining reproducibility on formalin-fixed paraffin-embedded tissue by quantitative immunofluorescence (QIF) using AQUA technology. We found antibodies against splice variants ERβ1 and ERβ5, but not ERβ2/cx, which were sensitive, specific, and reproducible. QIF staining of validated antibodies showed both ERβ1 and ERβ5 QIF scores, which have a normal (bell shaped) distribution on most cohorts assessed, and their expression is significantly associated with each other. Extensive survival analyses show that ERβ1 is not a prognostic or predictive biomarker for breast cancer. ERβ5 appears to be a context-dependent marker of worse outcome in HER2-positive and triple-negative patients, suggesting an unknown biological function in the absence of ERα.