Expression of S100A4, E-cadherin, alpha- and beta-catenin in breast cancer biopsies

FGFR‑related phenotypic and functional profile of CAFs in prognostication of breast cancer (Review)

While preclinical studies consistently implicate FGFR‑signalling in breast cancer (BC) progression, clinical evidence fails to support these findings. It may be that the clinical significance of FGFR ought to be analysed in the context of the stroma, activating or repressing its function. The present review aimed to provide such a context by summarizing the existing data on the prognostic and/or predictive value of selected cancer‑associated fibroblasts (CAFs)‑related factors, that either directly or indirectly may affect FGFR‑signalling. PubMed (https://pubmed.ncbi.nlm.nih.gov/) and Medline (https://www.nlm.nih.gov/medline/medline_home.html) databases were searched for the relevant literature related to the prognostic and/or predictive significance of: CAFs phenotypic markers (αSMA, S100A4/FSP‑1, PDGFR, PDPN and FAP), CAFs‑derived cognate FGFR ligands (FGF2, FGF5 and FGF17) or inducers of CAFs' paracrine activity (TGF‑β1, HDGF, PDGF, CXCL8, CCL5, CCL2, IL‑6, HH and EGF) both expressed in the tumour and circulating in the blood. A total of 68 articles were selected and thoroughly analysed. The findings consistently identified upregulation of αSMA, S100A4/FSP‑1, PDGFR, PDPN, HDGF, PDGF, CXCL8, CCL5, CCL2, IL‑6, HH and EGF as poor prognostic markers in BC, while evaluation of the prognostic value of the remaining markers varied between the studies. The data confirm an association of CAFs‑specific features with BC prognosis, suggesting that both quantitative and qualitative profiling of the stroma might be required for an assessment of the true FGFR's clinical value.

Pigmented Epidermotropic Breast Carcinoma: A Diagnostic Pitfall Mimicking Melanoma A Case Report and Literature Review

We report the clinical and pathologic features of a patient with breast carcinoma, who developed clinically visible pigmented skin lesions during the course of the disease. The combination of clinical pigmentation, histological pagetoid epidermal spread, and considerable melanin pigment within tumour cells lead to a misdiagnosis of melanoma. This case provides a striking example of the ability of epidermotropic breast carcinoma to mimic melanoma. A literature review is also reported.

Effect of aza-BODIPY-photodynamic therapy on the expression of carcinoma-associated genes and cell death mode

BACKGROUND

Breast cancer is the most common cancer affecting women worldwide.Photodynamic therapy(PDT) has now proven to be a promising form of cancer therapy due to its targeted and low cytotoxicity to healthy cells and tissues.PDT is a technique used to create cell death localized by light after application of a light-sensitive agent.Aza-BODIPY is a promising photosensitizer for use in PDT. Our results showed that aza-BODIPY-PDT induced apoptosis, probably through p53 and caspase3 in MCF-7 cells. Future studies should delineate the molecular mechanisms underlying aza-BODIPY-PDT-induced cell death for a better understanding of the signaling pathways modulated by the therapy so that this novel technology could be implemented in the clinic for treating breast cancer.

AIM

In this study,we aimed to determine the change in the expression levels of 88 carcinoma-associated genes induced by aza-BODIPY-PDT were analyzed so as to understand the specific pathways that are modulated by aza-BODIPY-PDT.

MATERIAL METHOD

In this study,the molecular basis of the anti-cancer activity of aza-BODIPY-PDT was investigated.Induction of apoptosis and necrosis in MCF-7 breast cancer cells after treatment with aza- BODIPY derivative with phthalonitrile substituents (aza-BODIPY) followed by light exposure was evaluated by Annexin V 7- Aminoactinomycin D (7-AAD) flow cytometry.

RESULTS

Aza-BODIPY-PDT induced cell death in MCF-7 cells treated with aza-BODIPY-PDT; flow cytometry revealed that 28 % of the cells died by apoptosis. Seven of the 88 carcinoma-associated genes that were assayed were differentially expressed -EGF, LEF1, WNT1, TCF7, and TGFBR2 were downregulated, and CASP3 and TP53 were upregulated - in cells subjected to aza-BODIPY-PDT.This made us think that the aza-BODIPY-PDT induced caspase 3 and p53-mediated apoptosis in MCF7 cells.

CONCLUSION

In our study,it was determined that the application of aza-BODIPY-PDT to MCF7 cells had a negative effect on cell connectivity and cell cycle.The fact that the same effect was not observed in control cells and MCF7 cells in the dark field of aza-BODIPY indicates that aza-BODIPY has a strong phodynamic anticancer effect.

Prognostic value of S100A4 and Glypican-3 in hepatocellular carcinoma in cirrhotic HCV patients

AIMS

Both S100A4 and Glypican-3 have been known to be engaged in HCC development and progression. This study aimed to evaluate both S100A4 and GPC3 expression in HCC tissues as a prognostic markers.

METHODS

Tissues from 70 patients of HCC in cirrhotic HCV patients were evaluated by immunohistochemistry using antibodies against SA100A4 and GPC3 and compared with tumor-adjacent tissue (controls). All cases were followed for 40 months.

RESULTS

GPC3 was more expressed in HCC (79%) than S100A4 (21%). S100A4 was more significantly expressed in cases showing metastasis, microscopic vascular emboli, necrosis, and grade III tumors. There was no relationship between overall survival and both S100A4 and GPC3. The only significant independent predictor for recurrence was decompensation (OR 3.037), while metastasis was significantly predicted by S100A4 expression (OR 9.63) and necrosis (OR 8.33).

CONCLUSION

S100A4 might be used as a prognostic marker for HCC, while GPC3 is a reliable marker of HCC diagnosis.

Pharmacological Inhibition of S100A4 Attenuates Fibroblast Activation and Renal Fibrosis

The TGF-β/Smad3 signaling pathway is an important process in the pathogenesis of kidney fibrosis. However, the molecular mechanisms are not completely elucidated. The current study examined the functional role of S100A4 in regulating TGF-β/Smad3 signaling in fibroblast activation and kidney fibrosis development. S100A4 was upregulated in the kidney in a murine model of renal fibrosis induced by folic acid nephropathy. Further, S100A4 was predominant in the tubulointerstitial cells of the kidney. Pharmacological inhibition of S100A4 with niclosamide significantly attenuated fibroblast activation, decreased collagen content, and reduced extracellular matrix protein expression in folic acid nephropathy. Overexpression of S100A4 in cultured renal fibroblasts significantly facilitated TGF-β1-induced activation of fibroblasts by increasing the expression of α-SMA, collagen-1 and fibronectin. In contrast, S100A4 knockdown prevented TGF-β1-induced activation of fibroblast and transcriptional activity of Smad3. Mechanistically, S100A4 interacts with Smad3 to stabilize the Smad3/Smad4 complex and promotes their translocation to the nucleus. In conclusion, S100A4 facilitates TGF-β signaling via interaction with Smad3 and promotes kidney fibrosis development. Manipulating S100A4 may provide a beneficial therapeutic strategy for chronic kidney disease.

A subset of activated fibroblasts is associated with distant relapse in early luminal breast cancer

Background

Early luminal breast cancer (BC) represents 70% of newly diagnosed BC cases. Among them, small (under 2 cm) BC without lymph node metastasis (classified as T1N0) have been rarely studied, as their prognosis is generally favorable. Nevertheless, up to 5% of luminal T1N0 BC patients relapse with distant metastases that ultimately prove fatal. The aim of our work was to identify the mechanisms involved in metastatic recurrence in these patients.

Methods

Our study addresses the role that autonomous and non-autonomous tumor cell features play with regard to distant recurrence in early luminal BC patients. We created a cohort of T1N0 luminal BC patients (tumors between 0.5–2 cm without lymph node metastasis) with metastatic recurrence (“cases”) and corresponding “controls” (without relapse) matched 1:1 on main prognostic factors: age, grade, and proliferation. We deciphered different characteristics of cancer cells and their tumor micro-environment (TME) by deep analyses using immunohistochemistry. We performed in vitro functional assays and highlighted a new mechanism of cooperation between cancer cells and one particular subset of cancer-associated fibroblasts (CAF).

Results

We found that specific TME features are indicative of relapse in early luminal BC. Indeed, quantitative histological analyses reveal that “cases” are characterized by significant accumulation of a particular CAF subset (CAF-S1) and decrease in CD4⁺ T lymphocytes, without any other association with immune cells. In multivariate analysis, TME features, in particular CAF-S1 enrichment, remain significantly associated with recurrence, thereby demonstrating their clinical relevance. Finally, by performing functional analyses, we demonstrated that CAF-S1 pro-metastatic activity is mediated by the CDH11/osteoblast cadherin, consistent with bones being a major site of metastases in luminal BC patients.

Conclusions

This study shows that distant recurrence in T1N0 BC is strongly associated with the presence of CAF-S1 fibroblasts. Moreover, we identify CDH11 as a key player in CAF-S1-mediated pro-metastatic activity. This is independent of tumor cells and represents a new prognostic factor. These results could assist clinicians in identifying luminal BC patients with high risk of relapse. Targeted therapies against CAF-S1 using anti-FAP antibody or CDH11-targeting compounds might help in preventing relapse for such patients with activated stroma.

Changes in Serum and Salivary Proteins in Canine Mammary Tumors

The aim of this study was to evaluate changes in serum and saliva proteomes in canine mammary tumors (CMT) using a high-throughput quantitative proteomic analysis in order to potentially discover possible biomarkers of this disease. Proteomes of paired serum and saliva samples from healthy controls (HC group, n = 5) and bitches with CMT (CMT group, n = 5) were analysed using a Tandem Mass Tags-based approach. Twenty-five dogs were used to validate serum albumin as a candidate biomarker in an independent sample set. The proteomic analysis quantified 379 and 730 proteins in serum and saliva, respectively. Of those, 35 proteins in serum and 49 in saliva were differentially represented. The verification of albumin in serum was in concordance with the proteomic data, showing lower levels in CMT when compared to the HC group. Some of the modulated proteins found in the present study such as haptoglobin or S100A4 have been related to CMT or human breast cancer previously, while others such as kallikrein-1 and immunoglobulin gamma-heavy chains A and D are described here for the first time. Our results indicate that saliva and serum proteomes can reflect physiopathological changes that occur in CMT in dogs and can be a potential source of biomarkers of the disease.

Expression and Roles of S100A4 in Anaplastic Cells of Canine Mammary Carcinomas

S100A4 (metastasin), a member of the S100 protein family, was initially identified in metastatic cells and is well established as a marker of aggressive human cancer. However, expression and roles of S100A4 in canine mammary tumors have not been clarified. In this study, expression of S100A4 was examined immunohistochemically in normal, hyperplastic, and neoplastic mammary glands of dogs. In all normal and benign lesions, S100A4 was restricted to a few stromal fibroblasts and inflammatory cells. However, in 7 of 57 (12%) of the malignant tumors examined, cytoplasmic and nuclear expression of S100A4 was observed in epithelial tumor cells and stromal cells. Particularly, the frequency of S100A4-positive anaplastic carcinomas was high (4/8 cases, 50%). Next, we established a novel cell line, named NV-CML, from a S100A4-positive canine mammary carcinoma. The cultured NV-CML cells and the tumors that developed in the immunodeficient mice after subcutaneous injection of the cells maintained the immunophenotype of the original tumor, including S100A4 expression. Using this cell line, we examined the cellular functions of S100A4 using RNA interference. S100A4 expression level in NV-CML cells transfected with small interfering RNA (siRNA) targeting canine S100A4 (siS100A4) was reduced to about one-fifth of those with negative-control siRNA (siNeg). Cell proliferation in WST-8 assay and cell migration in Boyden chamber assay were significantly decreased in siS100A4-transfected cells compared with siNeg-transfected cells. These findings suggest that S100A4 may be related to progression of canine mammary carcinomas via its influence on cell growth and motility.

S100A4-MYH9 Axis Promote Migration and Invasion of Gastric Cancer Cells by Inducing TGF-β-Mediated Epithelial-Mesenchymal Transition

Driver genes conducing to peritoneal metastasis in advanced gastric cancer remain to be clarified. S100A4 is suggested to evolve in metastasis of gastrointestinal cancer, we aim to explore the role of S100A4 plays in metastasis of advanced gastric cancer and the potential mechanism. Transfection of siRNA or cDNA was applied to alter the expression of protein S100A4 and MYH9, investigation of the expression of epithelial and mesenchymal transition (EMT) associated markers was followed. Cell migration assay was used to screen the alteration of migration ability regulated by S100A4 and MYH9. IHC analysis for tissue sample microarray was performed to reveal their relationship with clinical pathological parameters and potential capacity of predicting survival. Consistent overexpression of S100A4 and MYH9 were found in peritoneal metastasis and primary site compared with adjacent normal tissue. Low expression of S100A4 led to increased epithelial markers as wells as decline of mesenchymal makers, while overexpression of S100A4 led to inverse impact. S100A4 expression was closely correlated with increased migration ability and EMT process induced by TGF-β stimulation. Interference of S100A4 led to downregulation of MYH9 and inactivation of Smad pathway through participating in EMT process, which could be reversed by overexpression of MYH9. Moreover, co-expression of S100A4 and MYH9 was identified in tissue microarray and confirmed by immunofluorescence assay. In conclusion, overexpression of S100A4 and downstream molecular MYH9 in advanced gastric cancer predicted poor prognosis; oncogene S100A4 facilitate EMT process induced by TGF-β stimulation, suggesting a potential target in management of peritoneal metastasis of gastric cancer.

Smad3-mediated recruitment of the methyltransferase SETDB1/ESET controls Snail1 expression and epithelial-mesenchymal transition

During epithelial-mesenchymal transition (EMT), reprogramming of gene expression is accompanied by histone modifications. Whether EMT-promoting signaling directs functional changes in histone methylation has not been established. We show here that the histone lysine methyltransferase SETDB1 represses EMT and that, during TGF-β-induced EMT, cells attenuate SETDB1 expression to relieve this inhibition. SETDB1 also controls stem cell generation, cancer cell motility, invasion, metastatic dissemination, as well as sensitivity to certain cancer drugs. These functions may explain the correlation of breast cancer patient survival with SETDB1 expression. At the molecular level, TGF-β induces SETDB1 recruitment by Smad3, to repress Smad3/4-activated transcription of SNAI1, encoding the EMT "master" transcription factor SNAIL1. Suppression of SNAIL1-mediated gene reprogramming by SETDB1 occurs through H3K9 methylation at the SNAI1 gene that represses its H3K9 acetylation imposed by activated Smad3/4 complexes. SETDB1 therefore defines a TGF-β-regulated balance between histone methylation and acetylation that controls EMT.

Prognostic value of reduced E-cadherin expression in breast cancer: a meta-analysis

The prognostic value of E-cadherin expression in patients with breast cancer has been studied for years, yet results remain controversial. We thus performed a comprehensive evaluation of the association between E-cadherin expression and prognosis through a meta-analysis. The databases PubMed, Embase and Cochrane Library were searched. A total of 7,353 patients from 33 studies were subject to final analysis. The results showed there was a significant association between reduced expression of E-cadherin and overall survival (OS) (HR 1.79, 95% CI 1.41–2.27) and disease-free survival (DFS) (HR 1.62, 95% CI 1.31–1.99) in breast cancer. Downregulated expression of E-cadherin significantly correlated with tumor histological grade (OR 1.44, 95% CI 1.06–1.96), TNM stage (OR 2.44, 95% CI 1.75–3.41), tumor size (OR 1.38, 95% CI 1.18–1.60), lymph node status (OR 1.55, 95% CI 1.15–2.10), and progesterone receptor status (OR 1.44, 95% CI 1.10–1.88).This meta-analysis suggested that reduced E-cadherin expression might be a predictor of a poorer prognosis and could be a potentially new gene therapy target for breast cancer patients.

S100A4 in cancer progression and metastasis: A systematic review

Metastasis is the leading cause of cancer-related death and directly associates with cancer progression, resistance to anticancer therapy, and poor patient survival. Current efforts focusing on the underlying molecular mechanisms of cancer metastasis attract a special attention to cancer researchers. The epithelial-mesenchymal transition is a complex of molecular program during embryogenesis, inflammation, tissue fibrosis, and cancer progression and metastasis. S100A4, an important member of S100 family proteins, functions to increase the tumor progression and metastasis. The molecular mechanisms of S100A4 involving in the progression and metastasis are diverse in various malignant tumors. Detection of S100A4 expression becomes a promising candidate biomarker in cancer early diagnosis and prediction of cancer metastasis and therefore, S100A4 may be a therapeutic target. This review summarized up to date advancement on the role of S100A4 in human cancer development, progression, and metastasis and the underlying molecular events and then strategies to target S100A4 expression experimentally.

Prognostic significance of S100A4-expression and subcellular localization in early-stage breast cancer

PURPOSE

Prognostic factors are useful in order to identify early-stage breast cancer patients who might benefit from adjuvant treatment. The metastasis-promoting protein S100A4 has previously been associated with poor prognosis in breast cancer patients. The protein is expressed in diverse subcellular compartments, including the cytoplasm, extracellular space, and nucleus. Nuclear expression is an independent predictor of poor outcome in several cancer types, but the significance of subcellular expression has not yet been assessed in breast cancer.

METHODS

Nuclear and cytoplasmic expression of S100A4 was assessed by immunohistochemistry in prospectively collected tumor samples from early-stage breast cancer patients using tissue microarrays.

RESULTS

In patients not receiving adjuvant systemic therapy, nuclear or cytoplasmic expression was found in 44/291 tumors (15%). Expression of either nuclear or cytoplasmic S100A4 was associated with histological grade III, triple-negative subtype, and Ki-67-expression. Patients with S100A4-positive tumors had inferior metastasis-free and overall survival compared to S100A4-negative. When expression was analyzed separately, nuclear S100A4 was a significant predictor of outcome, while cytoplasmic was not. In patients who received adjuvant treatment 23/300 tumors (8%) were S100A4-positive, but no tumors displayed nuclear staining alone. S100A4-expression was strongly associated with histological grade III and triple-negative subtype. Although not significant, metastasis-free and overall survival was numerically reduced in patients with S100A4-positive tumors.

CONCLUSION

S100A4-expression was associated with poor outcome in early-stage breast cancer, but the low percentage of positive tumors and the modest survival differences imply that the clinical utility in selection of patients for adjuvant treatment is limited.

Downregulation of AKT3 Increases Migration and Metastasis in Triple Negative Breast Cancer Cells by Upregulating S100A4

BACKGROUND

Treatment of breast cancer patients with distant metastases represents one of the biggest challenges in today's gynecological oncology. Therefore, a better understanding of mechanisms promoting the development of metastases is of paramount importance. The serine/threonine kinase AKT was shown to drive cancer progression and metastasis. However, there is emerging data that single AKT isoforms (i.e. AKT1, AKT2 and AKT3) have different or even opposing functions in the regulation of cancer cell migration in vitro, giving rise to the hypothesis that inhibition of distinct AKT isoforms might have undesirable effects on cancer dissemination in vivo.

METHODS

The triple negative breast cancer cell line MDA-MB-231 was used to investigate the functional roles of AKT in migration and metastasis. AKT single and double knockdown cells were generated using isoform specific shRNAs. Migration was analyzed using live cell imaging, chemotaxis and transwell assays. The metastatic potential of AKT isoform knockdown cells was evaluated in a subcutaneous xenograft mouse model in vivo.

RESULTS

Depletion of AKT3, but not AKT1 or AKT2, resulted in increased migration in vitro. This effect was even more prominent in AKT2,3 double knockdown cells. Furthermore, combined downregulation of AKT2 and AKT3, as well as AKT1 and AKT3 significantly increased metastasis formation in vivo. Screening for promigratory proteins revealed that downregulation of AKT3 increases the expression of S100A4 protein. In accordance, depletion of S100A4 by siRNA approach reverses the increased migration induced by knockdown of AKT3.

CONCLUSIONS

We demonstrated that knockdown of AKT3 can increase the metastatic potential of triple negative breast cancer cells. Therefore, our results provide a rationale for the development of AKT isoform specific inhibitors.

Increased expression levels of S100A4 associated with hypoxia-induced invasion and metastasis in esophageal squamous cell cancer

Here, we explored the expression of S100A4 in esophageal squamous cell cancer (ESCC) tissues and investigated its role in hypoxia-induced invasion and metastasis in ESCC cell lines EC-1 and EC-9706. Immunohistochemistry analysis demonstrated that S100A4 was overexpressed in human ESCC tissues especially in ESCC tissues with deep invasion and lymph node metastasis. Hypoxia-induced S100A4 overexpression was observed in EC-1 and EC-9706 cells, in which it was associated with invasion and metastasis. Furthermore, we used EC-1 and EC-9706 cells again to upregulate or knockdown the expression S100A4 to investigate the mechanism role of S100A4 in hypoxia-induced invasion and metastasis in ESCC cells. And the results showed that S100A4 played an important role in promoting the invasion and metastasis of EC-1 and EC-9706 cells under hypoxia. Therefore, S100A4 overexpression might be an important mechanism by which hypoxia induced invasion and metastasis, and S100A4 could also be a potential target for the treatment of ESCC.

The expression of β-catenin in different subtypes of breast cancer and its clinical significance

The Wnt/β-catenin signaling pathway is implicated in mammary oncogenesis. Reports of β-catenin expression and its association with outcome in breast cancer are controversial. This study was performed to address the distribution of β-catenin expression in invasive breast cancer and the correlation between β-catenin expression and survival of breast cancer patients, and to determine whether β-catenin was specifically activated in any molecular subtypes. Immunohistochemistry was performed on a tissue microarray containing 169 invasive breast cancers to detect expression of β-catenin. One hundred thirty one of the 169 patients were followed up. Correlation between β-catenin expression and different molecular subtypes was determined using chi-square analysis. Overall survival (OS) was analyzed by Kaplan-Meier method with log-rank test. The invasive breast cancer displayed the different patterns of β-catenin expression from normal tissues with significantly increased cytoplasmic and nuclear staining of β-catenin. Aberrant β-catenin expression was observed in 109 in the 169 cases (64.50 %), and there was no difference in β-catenin expression in the four molecular subtypes. Furthermore, aberrant β-catenin expression was significantly associated with adverse outcome not only in the entire cohort but also in each of the different molecular subtypes. β-catenin activation is preferentially found and is associated with a poor clinical outcome in invasive breast cancer independent of molecular subtype.

S100A4 interacts with p53 in the nucleus and promotes p53 degradation

S100A4 is a small calcium-binding protein that is commonly overexpressed in a range of different tumor types, and it is widely accepted that S100A4 has an important role in the process of cancer metastasis. In vitro binding assays has shown that S100A4 interacts with the tumor suppressor protein p53, indicating that S100A4 may have additional roles in tumor development. In the present study, we show that endogenous S100A4 and p53 interact in complex samples, and that the interaction increases after inhibition of MDM2-dependent p53 degradation using Nutlin-3A. Further, using proximity ligation assay, we show that the interaction takes place in the cell nucleus. S100A4 knockdown experiments in two p53 wild-type cell lines, A549 and HeLa, resulted in stabilization of p53 protein, indicating that S100A4 is promoting p53 degradation. Finally, we demonstrate that S100A4 knockdown leads to p53-dependent cell cycle arrest and increased cisplatin-induced apoptosis. Thus, our data add a new layer to the oncogenic properties of S100A4 through its inhibition of p53-dependent processes.

Evaluation of plasma and tissue S100A4 protein and mRNA levels as potential markers of metastasis and prognosis in clear cell renal cell carcinoma

OBJECTIVES

To investigate levels of S100A4 protein in plasma and S100A4 mRNA in tumours from patients with clear cell renal cell carcinoma (CCRCC), and correlate these with metastasis, survival and levels of vascular endothelial growth factor (VEGF).

METHODS

Plasma S100A4 and VEGF protein concentrations were measured using enzyme-linked immuno sorbent assays in 39 healthy subjects and 68 consecutive patients with untreated CCRCC. Levels of S100A4 and VEGF mRNA in tumour and matched control (healthy) tissue samples were measured using realtime quantitative reverse transcription- polymerase chain reaction. Findings were analysed with respect to clinico pathological characteristics.

RESULTS

Plasma VEGF concentrations were higher in patients with CCRCC than in healthy subjects. S100A4 and VEGF mRNA levels were up-regulated in CCRCC tumour tissue compared with control tissue samples. Logistic regression analysis revealed that up-regulated tumour S100A4 and VEGF mRNA levels were independent risk factors for the presence of invasion and/or metastasis.

CONCLUSIONS

S100A4 and VEGF are associated with tumour invasion and metastasis, and may be useful prognostic markers in patients with CCRCC. S100A4 and VEGF may represent potential targets for therapeutic intervention.

S100A4 calcium-binding protein is key player in tumor progression and metastasis: preclinical and clinical evidence

The fatality of cancer is mainly bestowed to the property of otherwise benign tumor cells to become malignant and invade surrounding tissues by circumventing normal tissue barriers through a process called metastasis. S100A4 which is a member of the S100 family of calcium-binding proteins has been shown to be able to activate and integrate pathways both intracellular and extracellular to generate a phenotypic response characteristic of cancer metastasis. A large number of studies have shown an increased expression level of S100A4 in various types of cancers. However, its implications in cancer metastasis in terms of whether an increased expression of S100A4 is a causal factor for metastasis or just another after effect of several other physiological and molecular changes in the body resulting from metastasis are not clear. Here we describe the emerging preclinical and clinical evidences implicating S100A4 protein, in both its forms (intracellular and extracellular) in the process of tumorigenesis and metastasis in humans. Based on studies utilizing S100A4 as a metastasis biomarker and molecular target for therapies such as gene therapy, we suggest that S100A4 has emerged as a promising molecule to be tested for anticancer drugs. This review provides an insight in the (1) molecular mechanisms through which S100A4 drives the tumorigenesis and metastasis and (2) developments made in the direction of evaluating S100A4 as a cancer biomarker and drug target.

S100A4 silencing blocks invasive ability of esophageal squamous cell carcinoma cells

AIM: To investigate a potential role of S100A4 in esophagus squamous cell carcinoma metastasis (ESCCs).

METHODS: Expression of S100A4 and E-cadherin were analyzed in frozen sections from ESCCs (metastasis, n = 28; non-metastasis, n = 20) by reverse transcription-polymerase chain reaction, quantitative polymerase chain reaction and immunohistochemistry. To explore the influence of S100A4 on esophageal cancer invasion and metastasis, S100A4 was overexpressed or silenced by S100A4 siRNA in TE-13 or Eca-109 cells in vitro and in vivo.

RESULTS: We found the mRNA and protein levels of S100A4 expression in ESCCs was significantly upregulated, and more importantly, that expression of S100A4 and E cadherin are strongly negatively correlated in patients who had metastasis. It was indicated that overexpression of S100A4 in TE-13 and Eca-109 cells downregulates the expression of E-cadherin, leading to increased cell migration in vitro, whereas knockdown of S100A4 inhibited cell migration and upregulation of E-cadherin expression. Moreover, the loss of cell metastatic potential was rescued by overexpression of E-cadherin completely. In addition, nude mice inoculated with S100A4 siRNA-transfected cells exhibited a significantly decreased invasion ability in vivo.

CONCLUSION: S100A4 may be involved in ESCC progression by regulate E-cadherin expression, vector-based RNA interference targeting S100A4 is a potential therapeutic method for human ESCC.

Adherens junctions and cancer

Cadherins and catenins are the central cell-cell adhesion molecules in adherens junctions (AJs). This chapter reviews the knowledge concerning the role of cadherins and catenins in epithelial cancer and examines the published literature demonstrating the changes in the expression and function of these proteins in human cancer and the association of these changes with patient outcomes. The chapter also covers the mechanistic studies aiming at uncovering the significance of changes in cadherin and catenin expression in cancer and potential molecular mechanisms responsible for the causal role of AJs in cancer initiation and progression.

β-Catenin pathway activation in breast cancer is associated with triple-negative phenotype but not with CTNNB1 mutation

Aberrant β-catenin expression as determined by assessment of its subcellular localization constitutes a surrogate marker of Wnt signalling pathway activation and has been reported in a subset of breast cancers. The association of β-catenin/Wnt pathway activation with clinical outcome and the mechanisms leading to its activation in breast cancers still remain a matter of controversy. The aims of this study were to address the distribution of β-catenin expression in invasive breast cancers, the correlations between β-catenin expression and clinicopathological features and survival of breast cancer patients, and to determine whether aberrant β-catenin expression is driven by CTNNB1 (β-catenin encoding gene) activating mutations. Immunohistochemistry was performed on a tissue microarray containing 245 invasive breast carcinomas from uniformly treated patients, using two anti-β-catenin monoclonal antibodies. Selected samples were subjected to CTNNB1 exon 3 mutation analysis by direct gene sequencing. A good correlation between the two β-catenin antibodies was observed (Spearman's r >0.62, P<0.001). Respectively, 31 and 11% of the cases displayed lack/reduction of β-catenin membranous expression and nuclear accumulation. Complete lack of β-catenin expression was significantly associated with invasive lobular carcinoma histological type. Subgroup analysis of non-lobular cancers or non-lobular grade 3 carcinomas revealed that lack/reduction of β-catenin membranous expression and/or nuclear accumulation were significantly associated with oestrogen receptor negativity, absence of HER2 gene amplification and overexpression, lack/reduction of E-cadherin expression and tumours of triple-negative and basal-like phenotype. Univariate survival analysis revealed a significant association between β-catenin nuclear expression and shorter metastasis-free and overall survival in the whole cohort; however, β-catenin nuclear expression was not an independent predictor of outcome in multivariate analysis. No CTNNB1 mutations were identified in the 28 selected breast carcinomas analysed. In conclusion, β-catenin/Wnt pathway activation is preferentially found in triple-negative/basal-like breast carcinomas, is associated with poor clinical outcome and is unlikely to be driven by CTNNB1 mutations in breast cancer.

The metastasis-promoting protein S100A4 regulates mammary branching morphogenesis

High levels of the S100 calcium binding protein S100A4 also called fibroblast specific protein 1 (FSP1) have been established as an inducer of metastasis and indicator of poor prognosis in breast cancer. The mechanism by which S100A4 leads to increased cancer aggressiveness has yet to be established; moreover, the function of this protein in normal mammary gland biology has not been investigated. To address the role of S100A4 in normal mammary gland, its spatial and temporal expression patterns and possible function in branching morphogenesis were investigated. We show that the protein is expressed mainly in cells of the stromal compartment of adult humans, and during active ductal development, in pregnancy and in involution of mouse mammary gland. In 3D culture models, topical addition of S100A4 induced a significant increase in the TGFα mediated branching phenotype and a concomitant increase in expression of a previously identified branching morphogen, metalloproteinase-3 (MMP-3). These events were found to be dependent on MEK activation. Downregulation of S100A4 using shRNA significantly reduced TGFα induced branching and altered E-cadherin localization. These findings provide evidence that S100A4 is developmentally regulated and that it plays a functional role in mammary gland development, in concert with TGFα by activating MMP-3, and increasing invasion into the fat pad during branching. We suggest that S100A4-mediated effects during branching morphogenesis provide a plausible mechanism for how it may function in breast cancer progression.

An immunohistochemically positive E-cadherin status is not always predictive for a good prognosis in human breast cancer

Background:

In primary breast cancers dichotomic classification of E-cadherin expression, according to an arbitrary cutoff, may be inadequate and lead to loss of prognostic significance or contrasting prognostic indications. We aimed to assess the prognostic value of high and low E-cadherin levels in a consecutive case series (204 cases) of unilateral node-negative non-lobular breast cancer patients with a 8-year median follow-up and that did not receive any adjuvant therapy after surgery.

Methods:

Expression of E-cadherin was investigated by immunohistochemistry and assessed according to conventional score (0, 1+, 2+, 3+). Multiple correspondence analysis was used to visualise associations of both categorical and continuous variables. The impact of E-cadherin expression on patients outcome was evaluated in terms of event-free survival curves by the Kaplan–Meier method and proportional hazard Cox model.

Results:

Respect to intermediate E-cadherin expression values (2+), high (3+) or low (0 to 1+) E-cadherin expression levels had a negative prognostic impact. In fact, both patients with a low-to-nil (score 0 to 1+) expression level of E-cadherin and patients with a high E-cadherin expression level (score 3+) demonstrated an increased risk of failure (respectively, hazard ratio (HR)=1.71, confidence interval (CI)=0.72–4.06 and HR=4.22, CI=1.406–12.66) and an interesting association with young age.

Conclusions:

The findings support the evidence that high expression values of E-cadherin are not predictive for a good prognosis and may help to explain conflicting evidence on the prognostic impact of E-cadherin in breast cancer when assessed on dichotomic basis.

A novel human recombinant single-chain antibody targeting CD166/ALCAM inhibits cancer cell invasion in vitro and in vivo tumour growth

Screening a phage-display single-chain antibody library for binding to the breast cancer cell line PM-1 an antibody, scFv173, recognising activated leukocyte cell adhesion molecule (ALCAM, CD166) was isolated and its binding profile was characterized. Positive ALCAM immunohistochemical staining of frozen human tumour sections was observed. No ALCAM staining was observed in the majority of tested normal human tissues (nine of ten). Flow cytometry analyses revealed binding to 22 of 26 cancer cell lines of various origins and no binding to normal blood and bone marrow cells. Antibody binding inhibited invasion of the breast cancer cell line MDA-MB-231 by 50% in an in vitro Matrigel-coated membrane invasion assay. Reduced growth of tumours in nude mice was observed in an in vivo model in which the mice were injected subcutaneously with colorectal carcinoma HCT 116 cells and treated with scFv173 when compared to control. In summary, we have characterized a novel fully human scFv antibody recognising ALCAM on cancer cells and in tumour tissues that reduces cancer cell invasion and tumour growth in accordance with the hypothesised role for ALCAM in cell growth and migration control.

Overexpression of S100A4 in human cancer cell lines resistant to methotrexate

Background

Methotrexate is a chemotherapeutic drug that is used in therapy of a wide variety of cancers. The efficiency of treatment with this drug is compromised by the appearance of resistance. Combination treatments of MTX with other drugs that could modulate the expression of genes involved in MTX resistance would be an adequate strategy to prevent the development of this resistance.

Methods

The differential expression pattern between sensitive and MTX-resistant cells was determined by whole human genome microarrays and analyzed with the GeneSpring GX software package. A global comparison of all the studied cell lines was performed in order to find out differentially expressed genes in the majority of the MTX-resistant cells. S100A4 mRNA and protein levels were determined by RT-Real-Time PCR and Western blot, respectively. Functional validations of S100A4 were performed either by transfection of an expression vector for S100A4 or a siRNA against S100A4. Transfection of an expression vector encoding for β-catenin was used to inquire for the possible transcriptional regulation of S100A4 through the Wnt pathway.

Results

S100A4 is overexpressed in five out of the seven MTX-resistant cell lines studied. Ectopic overexpression of this gene in HT29 sensitive cells augmented both the intracellular and extracellular S100A4 protein levels and caused desensitization toward MTX. siRNA against S100A4 decreased the levels of this protein and caused a chemosensitization in combined treatments with MTX. β-catenin overexpression experiments support a possible involvement of the Wnt signaling pathway in S100A4 transcriptional regulation in HT29 cells.

Conclusions

S100A4 is overexpressed in many MTX-resistant cells. S100A4 overexpression decreases the sensitivity of HT29 colon cancer human cells to MTX, whereas its knockdown causes chemosensitization toward MTX. Both approaches highlight a role for S100A4 in MTX resistance.

Wnt/beta-catenin pathway activation is enriched in basal-like breast cancers and predicts poor outcome

Although Wnt/beta-catenin pathway activation has been implicated in mouse models of breast cancer, there is contradictory evidence regarding its importance in human breast cancer. In this study, invasive and in situ breast cancer tissue microarrays containing luminal A, luminal B, human epidermal growth factor receptor 2 (HER2)(+)/ER(-) and basal-like breast cancers were analyzed for beta-catenin subcellular localization. We demonstrate that nuclear and cytosolic accumulation of beta-catenin, a read-out of Wnt pathway activation, was enriched in basal-like breast cancers. In contrast, membrane-associated beta-catenin was observed in all breast cancer subtypes, and its expression decreased with tumor progression. Moreover, nuclear and cytosolic localization of beta-catenin was associated with other markers of the basal-like phenotype, including nuclear hormone receptor and HER2 negativity, cytokeratin 5/6 and vimentin expression, and stem cell enrichment. Importantly, this subcellular localization of beta-catenin was associated with a poor outcome and is more frequently observed in tumors from black patients. In addition, beta-catenin accumulation was more often observed in basal-like in situ carcinomas than other in situ subtypes, suggesting that activation of this pathway might be an early event in basal-like tumor development. Collectively, these data indicate that Wnt/beta-catenin activation is an important feature of basal-like breast cancers and is predictive of worse overall survival, suggesting that it may be an attractive pharmacological target for this aggressive breast cancer subtype.

Wild-type BRCA1, but not mutated BRCA1, regulates the expression of the nuclear form of beta-catenin

BRCA1 is an essential caretaker protein in the surveillance of DNA damage, is mutated in approximately 50% of all hereditary breast cancer cases, and its expression is frequently decreased in sporadic breast cancer. beta-Catenin is a multifunctional protein that forms adhesion complex with E-cadherins, alpha-catenin, and actin, and plays a central role in Wnt signaling through its nuclear translocation and activation of beta-catenin-responsive genes. Although significant progress has been made in understanding the Wnt/beta-catenin and BRCA1 signaling cascades, it is not known whether there is a link between beta-catenin and BRCA1. We observed that the expression of the active nuclear form of beta-catenin (also known as ABC, Ser37/Thr41-nonphosphorylated beta-catenin, dephosphorylated beta-catenin) was lower or absent in the nucleus in most BRCA1 familial breast cancer tissues (17 cases) compared with sporadic breast cancer (14 samples) and normal breast tissues. Wild-type-BRCA1, but not mutated BRCA1, interacted with beta-catenin and increased the levels of beta-catenin protein expression in vitro. Furthermore, H(2)O(2) induced the interaction of the nuclear form of beta-catenin with BRCA1. The active form of beta-catenin protein was downregulated upon exposure to H(2)O(2) in the nucleus of BRCA1-deficient HCC1937 breast cancer cells, whereas reconstitution of WT-BRCA1 in HCC1937 cells inhibited this downregulation. This study provides evidence of a novel interaction between BRCA1 and beta-catenin, and that loss of BRCA1 leads to impaired expression of the nuclear form of beta-catenin, which may contribute to the pathogenesis of breast cancer.

S100A4 and metastasis: a small actor playing many roles

The calcium-binding protein S100A4 promotes metastasis in several experimental animal models, and S100A4 protein expression is associated with patient outcome in a number of tumor types. S100A4 is localized in the nucleus, cytoplasm, and extracellular space and possesses a wide range of biological functions, such as regulation of angiogenesis, cell survival, motility, and invasion. In this review, we summarize the evidence connecting S100A4 and cancer metastasis and discuss the mechanisms by which S100A4 promotes tumor progression.

Interleukin-6 induces an epithelial-mesenchymal transition phenotype in human breast cancer cells

Breast tumor interleukin-6 (IL-6) levels increase with tumor grade, and elevated serum IL-6 correlates with poor breast cancer patient survival. Epithelial-mesenchymal transition (EMT) phenotypes such as impaired E-cadherin expression or aberrant Vimentin induction are associated with enhanced metastasis and unfavorable clinical outcome in breast cancer. Despite this fact, few tumor microenvironment-derived extracellular signaling factors capable of provoking such a phenotypic transition have been identified. In this study, we showed that IL-6 promoted E-cadherin repression among a panel of estrogen receptor-alpha-positive human breast cancer cells. Furthermore, ectopic stable IL-6 expressing MCF-7 breast adenocarcinoma cells (MCF-7(IL-6)) exhibited an EMT phenotype characterized by impaired E-cadherin expression and induction of Vimentin, N-cadherin, Snail and Twist. MCF-7(IL-6) cells formed xenograft tumors that displayed loss of E-cadherin, robust Vimentin induction, increased proliferative indices, advanced tumor grade and undifferentiated histology. Finally, we showed aberrant IL-6 production and STAT3 activation in MCF-7 cells that constitutively express Twist, a metastatic regulator and direct transcriptional repressor of E-cadherin. To our knowledge, this is the first study that shows IL-6 as an inducer of an EMT phenotype in breast cancer cells and implicates its potential to promote breast cancer metastasis.

Mislocalization of cell-cell adhesion complexes in tamoxifen-resistant breast cancer cells with elevated c-Src tyrosine kinase activity

c-Src activation has been implicated in metastasis of tamoxifen-resistant breast cancer. Here we investigated how c-Src activity affects cell adhesion using a tamoxifen-resistant variant of MCF-7 cells (MTR-3) containing elevated c-Src activity. In MTR-3 cells, adhesion proteins beta-catenin and E-cadherin are mislocalized, forming novel structures perpendicular to cell-cell junctions. c-Src is associated with beta-catenin/E-cadherin complexes and beta-catenin tyrosine phosphorylation is enhanced. Blocking c-Src tyrosine kinase activity decreased beta-catenin tyrosine phosphorylation and restored localization of beta-catenin and E-cadherin at cell-cell junctions. These findings suggest that inhibition of c-Src signaling may prevent metastasis of tamoxifen-resistant breast cancer.

S100A6 expression and function in human osteosarcoma

There is a critical need to identify markers that can accurately identify existing or predict future metastatic disease in patients with osteosarcoma since the majority of patients present with undetectable micrometastatic disease. We previously reported S100A6 is overexpressed in human osteosarcoma and increased expression of S100A6 by immunohistochemistry correlated with decreased clinical metastasis. We have established 11 primary cultures from biopsies of patients with osteosarcoma and ten of the 11 primary cultures have increased expression of S100A6 relative to normal human osteoblasts. To further explore possible mechanisms for metastasis suppression previously reported, we used in this report siRNA-mediated knockdown of S100A6 in four commonly used human osteosarcoma lines, then examined their cell adhesion, migration, and invasion properties. Knockdown of S100A6 expression inhibited cell adhesion and promoted cell migration and invasion in these lines. Conversely, S100A6 overexpression enhanced cell adhesion and inhibited cell invasion. Our data demonstrate S100A6 is commonly overexpressed in human osteosarcoma. S100A6 may inhibit osteosarcoma metastasis by promoting cell adhesion and inhibiting cell motility and invasion. Thus, S100A6 may be considered a potential marker for human osteosarcoma with prognostic value for identifying patients without metastases.

Crystal structure of metastasis-associated protein S100A4 in the active calcium-bound form

S100A4 (metastasin) is a member of the S100 family of calcium-binding proteins that is directly involved in tumorigenesis. Until recently, the only structural information available was the solution NMR structure of the inactive calcium-free form of the protein. Here we report the crystal structure of human S100A4 in the active calcium-bound state at 2.03 A resolution that was solved by molecular replacement in the space group P6(5) with two molecules in the asymmetric unit from perfectly merohedrally twinned crystals. The Ca(2+)-bound S100A4 structure reveals a large conformational change in the three-dimensional structure of the dimeric S100A4 protein upon calcium binding. This calcium-dependent conformational change opens up a hydrophobic binding pocket that is capable of binding to target proteins such as annexin A2, the tumor-suppressor protein p53 and myosin IIA. The structure of the active form of S100A4 provides insight into its interactions with its binding partners and a better understanding of its role in metastasis.

Immunohistochemical evaluation of e-cadherin, Ki-67 and PCNA in canine mammary neoplasias: correlation of prognostic factors and clinical outcome

E-cadherin is a cell-cell adhesion molecule and low e-cadherin expression is related to invasiveness and may indicate a bad prognosis in mammary neoplasms. The expression of cell proliferation markers PCNA and especially Ki-67, has also proved to have a strong prognostic value in this tumor class. The expression of these markers was related to the clinical-pathological characteristics of 73 surgically removed mammary tumors in female dogs by immunohistochemistry. There was no statistical correlation between these markers and death by neoplasm, survival time and disease-free interval. However, the loss of e-cadherin expression and marked Ki-67 expression (p=0.016) were considered statistically significant for the diagnosis (p=0.032). When evaluated as independent factors, there was evidence of the relationship between the loss of e-cadherin expression and high PCNA expression with changes in the body status (divided into obese, normal and cachectic) of female dogs (p=0.030); there was also evidence of the relationship between pseudopregnancy and e-cadherin alone (p=0.021) and for ulceration and PCNA alone (p=0.035). The significant correlation between the markers expression and these well known prognostic factors used individually or in combination suggests their prognostic value in canine mammary tumors.

Expression of S100A4 by a variety of cell types present in the tumor microenvironment of human breast cancer

The S100A4 protein, which is involved in the metastasis process, is a member of the S100 superfamily of Ca-binding proteins. Members of this family are multifunctional signaling proteins with dual extra and intracellular functions involved in the regulation of diverse cellular processes. Several studies have established a correlation between S100A4 protein expression and worse prognosis for patients with various malignancies including breast cancer. In this article, we have used specific antibodies in combination with immunohistochemistry (IHC) to identify the cell types that express S100A4 in human breast cancer biopsies obtained from high-risk patients. IHC analysis of 68 tumor biopsies showed that the protein is expressed preferentially by various cell types present in the tumor microenvironment (macrophages, fibroblasts, activated lymphocytes), rather than by the tumor cells themselves. Moreover, we show that the protein is externalized by the stroma cells to the fluid that bathes the tumor microenvironment, where it is found in several forms that most likely correspond to charge variants. Using a specific ELISA test, we detected a significant higher concentration of S100A4 in the tumor interstitial fluid (TIF) as compared to their corresponding normal counterparts (NIF).

Hypomethylation-induced expression of S100A4 in endometrial carcinoma

Expression of various S100 genes has been associated with clinically aggressive subtypes in a variety of different cancers. We hypothesized that S100A4 would be overexpressed in endometrial carcinoma compared to benign endometrium. Quantitative real-time RT-PCR (qRT-PCR) was used to quantify the mRNA level of S100A4 in benign endometrium (n=19), endometrioid adenocarcinoma (n=87), and non-endometrioid tumors (n=21). Immunohistochemistry was used to verify the results of qRT-PCR and to assess protein localization. Possible mechanisms of S100A4 gene regulation were also examined. S100A4 was overexpressed in the grade 3 endometrioid tumors, uterine papillary serous carcinoma, and uterine malignant mixed müllerian tumor. Expression in grade 1 and grade 2 endometrioid tumors was comparable to that of normal endometrium, which was quite low. Expression was significantly higher in stage III and IV tumors compared with stage I. By immunohistochemistry, S100A4 was expressed in the tumor cell cytoplasm of poorly differentiated tumors, but was not detected in normal endometrial glandular epithelium. In benign endometrium, S100A4 expression was confined to stromal cells. S100A4 was not regulated by estrogen or progesterone, and its expression in tumors was not significantly correlated to estrogen receptor or progesterone receptor content. However, methylation of the S100A4 gene was detected in benign endometrium and grade 1 tumors with low S100A4 expression. In contrast, grade 3 endometrioid tumors with high S100A4 mRNA and protein expression showed no methylation of the gene. These methylation results were verified in endometrial cancer cell lines with differential baseline levels of S100A4 protein. These results suggest that hypomethylation is an important mechanism of regulating the expression of the S100A4 gene. These results support the emerging concept that hypomethylation may play a role in the upregulation of genes during later stages of tumorigenesis.

Bench to bedside and back again: molecular mechanisms of alpha-catenin function and roles in tumorigenesis

The cadherin/catenin complex, comprised of E-cadherin, beta-catenin and alpha-catenin, is essential for initiating cell-cell adhesion, establishing cellular polarity and maintaining tissue organization. Disruption or loss of the cadherin/catenin complex is common in cancer. As the primary cell-cell adhesion protein in epithelial cells, E-cadherin has long been studied in cancer progression. Similarly, additional roles for beta-catenin in the Wnt signaling pathway has led to many studies of the role of beta-catenin in cancer. Alpha-catenin, in contrast, has received less attention. However, recent data demonstrate novel functions for alpha-catenin in regulating the actin cytoskeleton and cell-cell adhesion, which when perturbed could contribute to cancer progression. In this review, we use cancer data to evaluate molecular models of alpha-catenin function, from the canonical role of alpha-catenin in cell-cell adhesion to non-canonical roles identified following conditional alpha-catenin deletion. This analysis identifies alpha-catenin as a prognostic factor in cancer progression.

Detection of S100 protein from prostatic cancer patients using anti-S100 protein antibody immobilized on POS-PVA discs

The S100 proteins have been extensively used as cancer biomarkers. The objectives of the present work were to immobilize the antibody anti-protein S100 to a net of semi-interpenetrated of polysiloxane and polyvinyl alcohol (POS-PVA discs), to investigate its capacity to capture S100 protein from serum and to quantify it by ELISA in sera from patients with prostatic adenocarcinoma (n = 15) and healthy individuals (n = 10). Also these values were compared to the S100 protein expression in the prostatic tissue through immunohistochemistry. The POS-PVA discs fixed about 92.8% of the offered antibody (7.75 microg of antibody per disc). The best values of the immobilized no-marked antibody anti-S100 and serum dilution were found to be 10 microg and 1:400, respectively. Optical density (OD) values for the sera of patients (0.425 +/- 0.042) with prostatic adenocarcinoma were significantly lower (P < 0.05) compared to those established for the healthy individuals (1.034 +/- 0.124). In the immunohistochemistry study no significant variations were observed in the number of positive S100 cells between prostatic adenocarcinoma (153.45 +/- 16.82) and normal prostate (147.04 +/- 18.98). These results showed a clear difference between S100 proteins expressed in tissue and presented in serum during the prostatic tissue neoplasic transformation. Sera analysis was more sensitive than immunohistochemistry S100 protein detection in the prostate tissue besides the advantage to be less invasive method.

Focal S100A4 Protein Expression Is an Independent Predictor of Development of Metastatic Disease in Cystectomized Bladder Cancer Patients

OBJECTIVE

The prognosis of patients with apparently localized, operable, muscle-invasive bladder cancer depends to a large extent on the presence or absence of subclinical, microscopic distant metastases at the time of surgery. Expression of the S100A4 protein has been shown to correlate with the risk of metastasis in both animal tumour-model systems and clinical investigations in other tumour types. The purpose of the present study was to investigate the prognostic potential of S100A4 protein expression for predicting distant metastatic relapse in muscle-invasive bladder cancer.

METHODS

We analyzed 108 consecutive patients, treated for transitional cell bladder cancer with preoperative radiotherapy and cystectomy. Pretherapeutic biopsies of the bladder tumours were investigated for immunohistochemical expression of S100A4 protein and results, along with clinical and histopathological data, compared with the pattern of relapses over a 10+ yr follow-up period.

RESULTS

Focal S100A4 protein expression emerged as the only significant independent predictor of distant metastatic relapse and distant metastasis-free survival in multivariate analysis.

CONCLUSION

There is a potential role for this marker in denoting patients with high or low risk of distant relapse independent of clinical stage and grade.

Nuclear expression of S100A4 is associated with aggressive behavior of epithelial ovarian carcinoma: an important autocrine/paracrine factor in tumor progression

Although S100A4 expression has reportedly been associated with metastasis of various malignancies, little is known about its biological significance in ovarian carcinomas. In this study, we investigated expression and secretion of S100A4 and its extracellular function in ovarian carcinoma cells. We first used immunohistochemistry to examine the expression and localization of S100A4 in 113 epithelial ovarian neoplasms (24 benign, 20 borderline, and 69 malignant tumors) and analyzed its prognostic significance in patients with ovarian carcinoma. Then we investigated the expression, subcellular localization, and secretion of S100A4 in four ovarian carcinoma cell lines. Finally, we examined the effect of S100A4 treatment on the cell proliferation and invasiveness of ovarian carcinoma cells, along with activation of small GTPase, RhoA. Both cytoplasmic and nuclear expressions of S100A4 were significantly stronger in carcinomas than those in benign and borderline tumors. Ovarian carcinoma patients with strong nuclear S100A4 expression showed a significantly shorter survival than those without (P = 0.0045). This was not the case for cytoplasmic S100A4 expression. Ovarian carcinoma cell lines were shown to express S100A4, and secrete S100A4 into the culture media. Treatment with recombinant S100A4 resulted in the upregulation of S100A4 expression, translocation of S100A4 into the nucleus, and enhancement of invasiveness, which was associated with the upregulation of small GTPase, RhoA. These findings suggest that the nuclear expression of S100A4 is involved in the aggressive behavior of ovarian carcinoma and S100A4 is an autocrine/paracrine factor that plays an important role in the aggressiveness of ovarian carcinoma cells.

E-cadherin expression pattern in primary colorectal carcinomas and their metastases reflects disease outcome

AIM: To investigate the changes that occur in E-cadherin expression during the process of metastasis in colorectal cancer.

METHODS: E-cadherin expression was detected by immunohistochemistry and two indices of expression were calculated which reflected the level of expression and the locations (membrane and cytoplasm). Univariate and multivariate survival analyses were used to assess the value of these two E-cadherin indices as predictors of both disease-free (DFS) and disease-specific (DSS) survival.

RESULTS: E-cadherin membrane index (MI), but not cytoplasmic index (CI), was significantly higher in primary tumors than their metastases (P = 0.0001). Furthermore, both primary tumor MI and CI were higher among the patients who developed subsequent metastasis (P = 0.022 and P = 0.007, respectively). Interestingly, both indices were higher in liver metastase compared to other anatomic sites (MI, P = 0.034 and CI, P = 0.022). The CI of the primary tumors was a significant predictor of DFS (P = 0.042, univariate analysis), with a strong inverse correlation between CI and DFS (P = 0.006, multivariate analysis). Finally, the MI of primary tumor proved to be a significant independent predictor of DSS, with higher indices being associated with a more favorable outcome (P = 0.016).

CONCLUSION: Examination of E-cadherin expression and distribution in colorectal tumors can be extremely valuable in predicting disease recurrence. The observation that aberrant cytoplasmic expression of E-cadherin can predict disease recurrence is obviously of great importance for both patients and clinicians, and significantly affects decisions concerning the therapy and management of the patients.

Quantitative in situ analysis of beta-catenin expression in breast cancer shows decreased expression is associated with poor outcome

The role of beta-catenin in breast cancer and its prognostic value is controversial. The prognostic value had been assessed previously in a series of nonquantitative immunohistochemical studies with conflicting results. In efforts to clarify the relationship between beta-catenin protein expression and breast cancer prognosis, we have assessed a retrospective 600 case cohort of breast cancer tumors from the Yale Pathology archives on tissue microarrays. They were assessed using automated quantitative analysis (AQUA) with a series of array-embedded cell lines for which the beta-catenin concentration was standardized by an ELISA assay. The expression levels of the standard clinical markers HER2, estrogen receptor (ER), progesterone receptor (PR), and Ki-67 were also assessed on the same cohort. X-tile software was used to select optimal protein concentration cutpoints and to evaluate the outcome using a training set and a validation set. We found that low-level expression of membranous beta-catenin is associated with significantly worse outcome (38% versus 76%, 10-year survival, validation set log-rank P = 0.0016). Multivariate analysis of this marker, assessed in a proportional hazards model with tumor size, age, node status, nuclear grade, ER, PR, HER2, and Ki-67, is still highly significant with a hazard ratio of 6.8 (P < 0.0001, 95% confidence interval, 3.1-15.1). These results suggest that loss of beta-catenin expression at the membrane, as assessed by objective quantitative analysis methods, may be useful as a prognostic marker or may be part of a useful algorithm for prognosis in breast cancer.

E-cadherin Immunohistochemical Expression as a Prognostic Factor in Infiltrating Ductal Carcinoma of the Breast: a Systematic Review and Meta-Analysis

PURPOSE

Multiple studies examining the relationship between loss of E-cadherin expression, a pivotal event for evolving metastatic behavior among epithelially derived cancers, and 5-year survival in infiltrating ductal breast carcinoma have yielded inconclusive and contradictory results.

EXPERIMENTAL DESIGN

We conducted a systematic review of the PubMed database through August 2005 with no language restrictions to identify cohort studies that evaluated E-cadherin immunohistochemical expression as a prognostic marker for ductal breast carcinoma. 5-year all-cause mortality or 5-year breast cancer-specific mortality were the primary study outcomes. Meta-analysis was conducted using the REVMAN software and summary hazard ratios assuming both fixed effect and random effect models were calculated.

RESULTS

Ten retrospective cohort studies were identified. Reduced or absent E-cadherin expression significantly increased the risk of all-cause mortality [combined HR = 1.55; 95% CI = 1.08-2.23] whereas a non-significant association was observed for breast cancer-specific mortality [combined HR = 0.70; 95% CI = 0.39-1.27]. We documented substantial inter-study heterogeneity with respect to all aspects of clinical data collection, immunohistochemical staining and interpretation as well as statistical modeling. These factors could not be formally analyzed but they challenge the robustness of our calculated summary estimates.

CONCLUSIONS

Loss of E-cadherin expression may be an independent negative prognostic indicator for infiltrating ductal breast carcinoma and randomized, controlled studies evaluating this finding are justified. We encourage standardization of immunohistochemical techniques, data interpretation algorithms across laboratories and use of all-cause mortality to increase data compatibility and facilitate future efforts summarizing the utility of alternate prognostic markers in cancer.

Expression of the coxsackievirus- and adenovirus receptor in gastrointestinal cancer correlates with tumor differentiation

Modified adenoviruses represent a new approach to treatment of gastrointestinal cancer. However, their uptake by cells in many cases requires the major receptor for adenoviruses, the coxsackievirus and adenovirus receptor (CAR). Thus, lack of CAR expression is a potential cause of intrinsic resistance of tumor cells to this type of treatment. To evaluate this, we studied the localization of CAR protein in normal and malignant gastrointestinal tissues. In normal tissues, CAR was concentrated at sites of cell-cell interaction, in particular at the apico-lateral cellular surface. Expression was particularly strong around bile and pancreatic ducts, which is in agreement with CAR's physiological function as a tight-junction protein. In GI malignancies (esophageal, pancreatic, colorectal and liver cancer), expression of the receptor varied substantially. Loss of CAR expression at cell-cell junction was evident in many samples. A significant correlation between CAR expression and histological grade was found, with moderately to poorly differentiated tumors most frequently demonstrating loss or reduction of CAR expression. These data indicate that CAR expression is frequently altered in gastrointestinal malignancy, potentially reducing the efficacy of adenovirus-based therapies.

Transforming growth factor-beta receptor inhibition enhances adenoviral infectability of carcinoma cells via up-regulation of Coxsackie and Adenovirus Receptor in conjunction with reversal of epithelial-mesenchymal transition

Expression of the Coxsackie and Adenovirus Receptor (CAR) is frequently reduced in carcinomas, resulting in decreased susceptibility of such tumors to infection with therapeutic adenoviruses. Because CAR participates physiologically in the formation of tight-junction protein complexes, we examined whether molecular mechanisms known to down-regulate cell-cell adhesions cause loss of CAR expression. Transforming growth factor-beta (TGF-beta)-mediated epithelial-mesenchymal transition (EMT) is a phenomenon associated with tumor progression that is characterized by loss of epithelial-type cell-cell adhesion molecules (including E-cadherin and the tight junction protein ZO-1), gain of mesenchymal biochemical markers, such as fibronectin, and acquisition of a spindle cell phenotype. CAR expression is reduced in tumor cells that have undergone EMT in response to TGF-beta. This down-regulation results from repression of CAR gene transcription, whereas altered RNA stability and increased proteasomal protein degradation play no role. Loss of CAR expression in response to TGF-beta is accompanied by reduced susceptibility to adenovirus infection. Indeed, treatment of carcinoma cells with LY2109761, a specific pharmacologic inhibitor of TGF-beta receptor types I and II kinases, resulted in increased CAR RNA and protein levels as well as improved infectability with adenovirus. This was observed in cells induced to undergo EMT by addition of exogenous TGF-beta and in those that were transformed by endogenous autocrine/paracrine TGF-beta. These findings show down-regulation of CAR in the context of EMT and suggest that combination of therapeutic adenoviruses and TGF-beta receptor inhibitors could be an efficient anticancer strategy.

Validation of molecular targets in prostate cancer

As prostate cancer is not a single disease, it is important to identify the pivotal pathway in the patient being treated. The molecular environment is the site of current oncological research to define new therapeutic targets for hormone-refractory disease, offering the potential to eventually individualize treatment through stratification of pathways. Targets may be validated either phenotypically (e.g. androgen receptor, cadherin) or functionally (e.g. prostate cancer-specific genes). In addition, several other candidates are potentially suitable, while others await discovery. Important initial steps have been made in the search for prostate cancer stem cells; identifying stem cells and the stromal, hormonal, and other signalling molecules that influence their behaviour would have important implications for managing prostate cancer. Although individual therapeutic pathways might be ineffective in a particular molecular environment, combinations of approaches might be capable of producing synergistic effects. A multimodal approach thus might be the best solution. Determining where best to search for a molecular target, and validating whether the target is associated with a sufficiently aggressive malignant process to justify further study is difficult, but the potential benefits are enormous.

Increased expression of S100A6 is associated with decreased metastasis and inhibition of cell migration and anchorage independent growth in human osteosarcoma

While most osteosarcoma patients have metastatic or micrometastatic lesions, less than 15% of them have clinically detectable metastatic diseases at presentation. To identify potential markers that may predict osteosarcoma metastasis, we analyzed the expression of S100A6 in 50 osteosarcoma cases and found that 84% of the analyzed specimens stained positive for S100A6. There is a trend towards decreased clinically evident metastasis with increased S100A6 staining. Overexpression of S100A6 in osteosarcoma cells decreases cell motility and anchorage independent growth on collagen gels. Our findings provide evidence that, while S100A6 is commonly overexpressed in human osteosarcoma, loss of its expression correlates with a metastatic phenotype.