Dysadherin Expression Research Articles

The dysadherin/FAK axis promotes individual cell migration in colon cancer.

Dysregulation of cancer cell motility is a key driver of invasion and metastasis. High dysadherin expression in cancer cells is correlated with invasion and metastasis. Here, we found the molecular mechanism by which dysadherin regulates the migration and invasion of colon cancer (CC). Comprehensive analysis using single-cell RNA sequencing data from CC patients revealed that high dysadherin expression in cells is linked to cell migration-related gene signatures. We confirmed that the deletion of dysadherin in tumor cells hindered local invasion and distant migration using in vivo tumor models. In this context, by performing cell morphological analysis, we found that aberrant cell migration resulted from impaired actin dynamics, focal adhesion turnover and protrusive structure formation upon dysadherin expression. Mechanistically, the activation of focal adhesion kinase (FAK) was observed in dysadherin-enriched cells. The dysadherin/FAK axis enhanced cell migration and invasion by activating the FAK downstream cascade, which includes the Rho family of small GTPases. Overall, this study illuminates the role of dysadherin in modulating cancer cell migration by forcing actin dynamics and protrusive structure formation via FAK signaling, indicating that targeting dysadherin may be a potential therapeutic strategy for CC patients.

Dysadherin awakens mechanical forces and promotes colorectal cancer progression.

Rationale: Dysadherin is a tumor-associated, membrane-embedded antigen found in multiple types of cancer cells, and associated with malignant behavior of cancer cells; however, the fundamental molecular mechanism by which dysadherin drives aggressive phenotypes of cancer is not yet fully determined.Methods: To get a mechanistic insight, we explored the physiological relevance of dysadherin on intestinal tumorigenesis using dysadherin knockout mice and investigated its impact on clinicopathological features in patients with advanced colorectal cancer (CRC). Next, to discover the downstream signaling pathways of dysadherin, we applied bioinformatic analysis using gene expression data of CRC patient tumors and dysadherin knockout cancer cells. Additionally, comprehensive proteomic and molecular analyses were performed to identify dysadherin-interacting proteins and their functions.Results: Dysadherin deficiency suppressed intestinal tumorigenesis in both genetic and chemical mouse models. Moreover, increased dysadherin expression in cancer cells accounted for shorter survival in CRC patients. Comprehensive bioinformatics analyses suggested that the effect of dysadherin deletion is linked to a reduction in the extracellular matrix receptor signaling pathway. Mechanistically, the extracellular domain of dysadherin bound fibronectin and enhanced cancer cell adhesion to fibronectin, facilitating the activation of integrin-mediated mechanotransduction and leading to yes-associated protein 1 activation. Dysadherin-fibronectin interaction promoted cancer cell growth, survival, migration, and invasion, effects collectively mediated the protumor activity of dysadherin.Conclusion: Our results highlight a novel function of dysadherin as a driver of mechanotransduction that stimulates CRC progression, providing a potential therapy strategy for CRC.

Precision Targeting of Ion Channel Blocker for the Treatment of AML

The survival rate of patients with acute myeloid leukemia (AML) remains modest and thus, there is a clear need for advanced treatments. Here we describe two drug leads for AML that inhibit cellular sodium release without requiring drug internalization. EDC1 and EDC8 are two very potent extracellular antibody drug conjugates that selectively inhibit the all-important Na,K-ATPase, an ion pump required by cells to export excess sodium and to maintain ion gradients needed to import and export many important nutrients and waste products. We first demonstrate that dysadherin (a known metastatic cancer marker), is expressed on the surface many types of AML cell lines and can be used to direct Na,K-ATPase inhibitors using EDC1. We next demonstrate that ATRA inducible AML cells types are selectively destroyed with Na,K-ATPase inhibitors targeted to CD38 using EDC8 and ATRA.Since dysadherin expression is a known to be correlated to metastasis and stemness but yet to be studied in AML, we first analyzed a number of leukemia cell lines and AML patient samples for dysadherin expression by analyzing their surface expression and/or their sensitivity to EDC1. We observed that many cultured AML cells express dysadherin and are sensitive to EDC1 with EC50 values ranged from 0.02 to 1.0 nanoMolar and cell viability after 72 hours of exposure ranging from zero to 10%. For the three primary AML patient specimens analyzed, dysadherin expression was seen. Interestingly, in two of these three samples, the majority of intense staining was found in the CD123+ CD34+ population.Since CD38 expression and inducible expression can now be diagnosed in patients with AML, we analyzed if ATRA was required to sensitize AML to EDC8. Using multiple leukemic cell lines (HL60, U937, MV411, KG1, K562, and OCI/AML3) known to express CD38 with or without requiring ATRA, we analyzed EDC8 sensitivity before and after ATRA addition. We found that CD38 expression was required for EDC8 sensitivity and once expressed, EDC8 displayed potent activity with few viable cells detectable.Further studies analyzing dysadherin and CD38 expression in patient samples are needed to better understand the AML cell populations that may be affected by these EDCs but these results show the potential of this new type of antibody drug conjugate technology for the treatment of AML. EDCs that inhibit a required membrane bound ion pump with the precision of antibodies without requiring internalization may provide a new tool for doctors in their fight against AML. DisclosuresMarshall:CENTROSE: Employment. Malavasi:Jaansen Pharmaceuticals: Research Funding. Prudent:CENTROSE: Employment, Equity Ownership.

Evaluation of the Effect of Foeniculum vulgare on the Expression of E-Cadherin, Dysadherin and Ki-67 in BALB/C Mice with 4T1 Model of Breast Cancer

Introduction: Breast cancer is described as a serious disease and one of the important factors of cancer-related deaths. Considering the drug resistance, special attention has been paid to natural compounds. This study aimed at evaluating the anti-metastatic activity of fennel in a breast cancer mouse model.Methods: A total of 28 adult female BALB/C mice were used in this study. Breast cancer was induced by subcutaneous injection of 4T1 cells in the right lower flank. The mice received fennel extracts daily via intraperitoneal injection for two weeks. Meanwhile, tumor volume was measured every day using calipers. After two weeks, each animal was anesthetized. The expression levels of ki-67 and dysadherin as tumor markers, as well as E-cadherin as a tumor suppressor, were measured in tumor tissue and ovary. Also the expression of her2 was measured in ovary.Results: Tumor size significantly decreased after nine days treatment of the fennel. Fennel treatment caused an increase in the ratio of the expression of E-cadherin to Ki-67 and dysadherin in the tumor tissues. On the other hand, the expression of Ki-67 and HER2 decreased in the ovary.Conclusion: Based on our findings, fennel has anti-tumor and anti-metastatic activities against aggressive cancers.

Prognostic and Clinicopathological Significance of EphB3 and Dysadherin Expression in Extrahepatic Cholangiocarcinoma.

AimEphB3 and dysadherin are involved in tumorigenesis and progression of many neoplasms. However, the roles of EphB3 and dysadherin in extrahepatic cholangiocarcinoma (ECC) remain to be revealed. In this study, we aimed to evaluate the expression of EphB3 and dysadherin, and investigate their clinicopathological significance in ECC.MethodsWe examined EphB3 and dysadherin expression in 100 ECC, 30 peritumoral tissues, 10 adenoma and 15 normal biliary tract tissues using EnVision immunohistochemistry. The relationship between EphB3 or dysadherin expression and clinicopathological features was evaluated using the χ2 test or Fisher’s exact test. The overall survival of ECC patients was analyzed using Kaplan-Meier univariate survival analysis and Log rank tests.ResultsWe found that EphB3 expression was significantly down-regulated and dysadherin expression was significantly up-regulated in ECC tissues compared with normal tissues (P < 0.01). EphB3 expression was negatively correlated with dysadherin expression in ECC (P < 0.01). The positive rate of EphB3 expression and negative rate of dysadherin expression was significantly higher in patients with well-differentiated type, no lymph node metastasis, no surrounding tissues and organs invasion, early TNM stages (I + II) and radical resection (P < 0.01). The survival of ECC patients with positive EphB3 or negative dysadherin expression was significantly longer than patients with negative EphB3 or positive dysadherin expression (P < 0.01). Cox multivariate analysis demonstrated that negative EphB3 or positive dysadherin expression were independent poor prognostic factors in ECC patients. The ROC curves suggested that EphB3 and dysadherin combined diagnostic efficacy (AUC=0.688, 95%CI: 0.603-0.772) was significantly higher EphB3 diagnostic efficacy (AUC=0.654, 95%CI: 0.564-0.743) or dysadherin diagnostic efficacy (AUC=0.648, 95%CI: 0.558-0.737) alone.ConclusionEphB3 and dysadherin are involved in the carcinogenesis and progression of ECC, and ECC patients with negative EphB3 or positive dysadherin expression have a poor prognosis.

Dysadherin specific drug conjugates for the treatment of thyroid cancers with aggressive phenotypes

BackgroundEDC1 is a novel type of antibody-drug conjugate which binds and inhibits the Na,K-ATPase on the surface of cancer cells expressing dysadherin. The purpose of this study was to determine the expression of dysadherin in different types of thyroid carcinoma, and evaluate the therapeutic potential of EDC1 for thyroid carcinomas.MethodsThyroid tissues from 158 patients were examined for dysadherin expression and correlation with clinicopathological features. Thyroid cancer cell lines were examined for the expression of dysadherin and effective dose range of EDC1.RESULTSOne in 53 benign thyroid tissues and 62% of thyroid cancers expressed dysadherin. All anaplastic and a majority of papillary thyroid cancers overexpressed dysadherin, while 25% of follicular thyroid cancers was found to be positive for dysadherin. Dysadherin expression significantly correlated with extrathyroidal extension and lymph node metastases in papillary thyroid cancer. Five of six human thyroid cancer cell lines analyzed expressed high levels of dysadherin. Of those cells lines sensitive to EDC1, half maximal effective concentrations (EC50) were observed to be between 0.125 nM and 1 nM.ConclusionsEDC1 showed selective inhibition of growth in thyroid cancer cells with moderate to high expression of dysadherin, thus could be a specific and effective treatment.

Dysadherin Expression is Associated with Advanced Tumorstage while Complexity Index is Related to Poorly Differentiated Tumors in Colon Carcinoma

Dysadherin expressions are associated with the aggressive tumors that show poor prognosis in different types of cancers. Aggressive tumors often presented with infiltrative type of growth pattern in colon cancer and that has been associated with poor prognosis as well. The aim of this was to evaluate Dysadherin expression in paired normal and tumor samples, and tumor growth pattern in the form of complexity index in the same patient colon cancer samples, and finally to correlate with each other and different clinical and pathological parameters. To evaluate Dysadherin expression, we selected 45 patients and performed RT-qPCR on normal and paired tumor samples. To determine growth pattern, we captured pictures from the immunohistochemically stained tumor invasive fronts and then evaluated by using Photoshop CS, Fovea Pro, and Image J computer programs. Paired t test was applied for the Dysadherin expression between normal and paired normal samples while Pearson chi square and Fischer exact test between dichotomized Dysadherin expression, complexity index and different clinicopathological parameters. Mean Dysadherin expression in normal samples was 0.155+0.0167 and in tumor 0.869+0.083 and was significantly different between two groups of samples (P value<0.0001). In dichotomized groups, increased Dysadherin expression was significantly correlated with the lymph node metastasis and advanced Dukes stages. Higher complexity index was significantly associated with low differentiated tumors while non-significantly with other clinicopathological parameters. In conclusion, Dysadherin expression and tumor growth pattern are independent features, where Dysadherin expression is associated with advanced Dukes staged tumors and complexity index with the poorly differentiated tumors.

Aberrantly regulated dysadherin and B-cell lymphoma 2/B-cell lymphoma 2-associated X enhances tumorigenesis and DNA targeting drug resistance of liver cancer stem cells.

Cancer stem cells (CSCs) in hepatocellular carcinoma (HCC) are frequently resistant to current therapeutic regimens and therefore responsible for tumor recurrence. Previous studies have reported that expression levels of dysadherin in CSCs may be used as a prognostic indicator, which is also responsible for treatment failure and poor survival rates. The present study analyzed the association of enhanced dysadherin levels with drug resistance and evasion of apoptosis in human HCC SP cells. An SP of 3.7% was isolated from human HCC cells using fluorescence-activated cell sorting. These SP cells displayed elevated levels of dysadherin and stemness proteins as well as high resistance to chemotherapeutic drugs and apoptosis. In order to reveal the possible link between dysadherin levels and tumorigenesis of SP cells, small interfering RNA technology was used to knockdown the expression of dysadherin in SP cells. Of note, the siRNA-transfected SP cells showed significantly reduced levels of stemness proteins, and were more sensitive to DNA-targeting drugs and apoptotic cell death as compared to non-transfected cells. Furthermore, in vivo experiments in NON/SCID mice indicated that dysadherin-expressing SP cells were highly tumorigenic, as they were able to induce tumor growth. The SP cell-derived tumor tissues in turn showed elevated dysadherin levels. The results of the present study therefore suggested that knockdown of dysadherin suppressed the tumorigenic properties of cancer stem-like SP cells. Hence, dysadherin is a valuable potential target for the development of novel anti-cancer drugs.

Effect of aberrantly regulated dysadherin and Bcl-2/Bax2 on tumorigenesis and DNA targeting drug resistance of liver cancer stem cells.

e15167 Background: Presence of cancer stem cells (CSCs) in hepatocellular carcinoma (HCC) are highly potential to evade current therapeutic regimen and responsible for tumor recurrence. Studies reported that expression of dysadherin in CSCs could be used as a prognostic indicator, also responsible for treatment failure and poor survival rates. In the current study, we analyzed the role of enhanced dysadherin in drug and apoptosis resistance in human HCC SP cells. Methods: SP cells from 19 human HCC patients were sorted by FACs. RNA interference evaluated the expression of stemness genes(CD133, ABCG2, OCT-4, EpCAM, BCL-2, BAX) in SP cells before and after dysadherin knock down using RT-PCR analysis. Immunohistochemistry (IHC) assays assessed dysadherin protein expression in SP cells. Multidrug resistance assay tested the capacity of SP cells before and after dysadherin knock down treatment with chemotherapy drugs (carboplatin, 5-Flurouracil and doxorubicin).Tumor xenograft experiment evaluate the tumorigen...

Alterations in dysadherin expression and F-actin reorganization: a possible mechanism of hypericin-mediated photodynamic therapy in colon adenocarcinoma cells

Dysadherin is a recently found anti-adhesion molecule, therefore detection and down regulation of its expression is promising in cancer treatment. The up-regulation of dysadherin contributes to colon cancer recurrence and metastasis. Dysadherin also has connections with cytoskeletal proteins and it can cause alterations in the organisation of filamentous actin (F-actin) in metastatic cancers. In this study, hypericin (HYP)-mediated photodynamic therapy (PDT) was performed in two different grade colon adenocarcinoma cell lines HT-29 (Grade I) and Caco-2 (Grade II). Cells were treated with 0.04, 0.08 or 0.15μM HYP concentrations and irradiated with (4J/cm(2)) fluorescent lamps. The effects of HYP was examined 16 and 24h after the activation. We investigated for the first time the effect of HYP-mediated PDT on the expression of dysadherin and F-actin organisation. According to the results, HYP mediated PDT caused a decrease in gene expression and immunofluorescence staining of dysadherin and an increase in actin stress fibers and actin aggregates in HT-29 and Caco-2 cell lines. Besides, cytotoxicity, number of floating cells and apoptotic index changed depending on the cell type, HYP concentration and incubation time. We have demonstrated for the first time that dysadherin and F-actin could be target molecules for HYP-mediated PDT in HT-29 and Caco-2 colon cancer cell lines.

838P - Expression and Clinical Importance of E-Cadherin, Dysadherin and Chemokine Ligand 2 (CCL2) in Renal Cell Carcinoma (RCC)

ABSTRACT Aim Dysadherin is a cell adhesion molecule that related with aggresiveness and progression in many cancers. Dysadherin acts role either with E-cadherine dependent or CCL-2 mediated that E-cadherin independent. We studied expression and clinical importance of dysadherin and e-cadherin as adhesion molecules and CCL2 in RCC. Method Between 2006 and 2010, 38 patients with RCC were evaluated retrospectively. Median age of the patients (27 male, 11 female) was 60 (range, 33–84). While median tumor size was 5.75 cm (range, 2–30 cm), 13 patients were stage 4, one patient was stage 3, 5 patients were stage 2, 19 patients were stage 1. 15 patients were Fuhrmann grade ¾, 21 patients (55.3%) had capsule invasion, 10 patients (26.3%) had perirenal fat tissue involvement and 4 patients had (10.5%) renal vein thrombosis. Dysadherin did not express in 10 patients. Low expression (less than %30) was detected in 25 patients (65.8%), enhanced expression (more than 30%) was detected in 3 patients (%7.9). E-cadherin did not express in 11 patients (28.9%), low expression was detected in 23 patients (60.5%), moderate-high expression was detedcted 4 patients (10.6%). CCL2 did not express in 14 patients, low expression was detected in 7 patients (%18.4), moderate-high expression was detected in 17 patients (44.3%). Although moderate positive correlation between dysadherin and CCL2 (r= +0,25, p = 0.49), e-cadherin and CCL2 (r= +0.25, p = 0.33) were detected, moderate negative correlation between dysadherin and e-cadherin was detected (r= +0.22, p = 0.66). Moderate negative correlation was detected between grade of tumor and e-cadherin (r= -0.25, p = 0.49). Median overall survival (OS) was 46.6 months (range, 38.9-54.3), In univariate analysis, stage, grade of tumor, capsule invasion, tumor thrombosis, perirenal fat tissue involvement were significant interaction on OS (p 0.05). Stage and vascular thrombosis were significant on overall survival in multivariate analysis. Conclusion This is the first study that evaluated adhesion molecules in RCC and there is no association these parameters and clinical outcome. Disclosure All authors have declared no conflicts of interest.

Dysadherin expression promotes the motility and survival of human breast cancer cells by AKT activation

High dysadherin expression has been recognized as a biological predictor of metastasis and poor prognosis for many different cancer types; however, the molecular mechanisms of how dysadherin affects cancer progression are still poorly understood. In this study, we examined whether AKT signaling could link dysadherin expression with downstream events that promote the metastatic potential of human breast cancer cells. Immunohistochemical analysis of breast cancer tissues showed that dysadherin expression was highly associated with elevated expression of phospho-AKT. The introduction of dysadherin cDNA into BT-474, MCF-7 and T-47D breast cancer cell lines enhanced their levels of AKT phosphorylation, while knockdown of dysadherin in MDA-MB-231 and Hs578T breast cancer cell lines suppressed AKT phosphorylation. Treatment with the AKT inhibitor triciribine suppressed dysadherin-mediated pro-metastatic effects, including epithelial-mesenchymal transition, cell motility and drug resistance. These findings suggest that dysadherin might contribute to breast cancer progression through AKT activation.

Immunohistochemical Study of Correlation Between Histologic Subtype and Expression of Epithelial-Mesenchymal Transition-Related Proteins in Synovial Sarcomas

Synovial sarcomas are mesenchymal tumors with epithelial nature and comprise biphasic and monophasic fibrous subtypes. However, factors determining epithelial or spindle cell differentiation are still unexplored. Aberrant epithelial-mesenchymal transition has been implicated in the pathogenesis of diverse human malignancies. To analyze the correlation between cellular phenotype and expression of proteins associated with different epithelial-mesenchymal transition-related pathways. Immunohistochemical analysis of E-cadherin, Snail, Slug, and dysadherin, components of the Wnt/wingless and PI3K/Akt pathways, was performed on 14 biphasic and 27 monophasic fibrous tumors. In monophasic fibrous tumors, increased expression of Snail (17 of 27; 63%), Slug (18 of 27; 67%), and dysadherin (14 of 27; 52%) and activation of Wnt (nucleocytoplasmic β-catenin accumulation in 63%; n = 27; and positive expression of GSK3 and pGSK3 in 24 of 27 [89%] and 21 of 27 [78%], respectively) and PI3K/Akt (Akt: 22 of 27 [81%]; pAkt: 25 of 27 [93%]; and PI3K: 20 of 27 [74%]) signaling correlated significantly with inactivated E-cadherin expression (1 of 27; 4%) (all P < .05). In contrast, preserved E-cadherin expression (12 of 14; 86%) in the glandular component of the biphasic subtype was associated with significantly decreased Snail (3 of 14; 21%) (P = .02) and dysadherin (2 of 14; 14%) expression (P < .001). Overexpression of Snail, Slug, and dysadherin and activation of Wnt and PI3K/Akt signaling was associated with inactivated E-cadherin in the spindle cells of monophasic fibrous synovial sarcomas, further supporting the hypothesis that this subtype may have developed through neoplastic epithelial-mesenchymal transition.

Expression of dysadherin in the human male reproductive tract and in spermatozoa

To study expression of dysadherin in human testis, epididymis, and spermatozoa. Prospective study. Basic research laboratory. Testis, epididymis, and testicular spermatozoa from patients under treatment and semen from volunteer donors. Reverse transcription-polymerase chain reaction, immunohistochemistry, immunocytochemistry, and Western immunoblotting. Dysadherin messenger RNA (mRNA) analysis in testis, epididymis, and ejaculated spermatozoa, immunohistochemistry of both tissues, Western immunoblotting of tissue/cell extracts, and immunocytochemistry of spermatozoa. Dysadherin mRNA was found in testis, epididymis, and ejaculated spermatozoa. Whereas testis and spermatozoa exhibited a distinctive 91-kDa protein form, the epididymis showed a 50-kDa moiety, also found in MDA-MB-231 breast cancer cells. Nucleotide sequence analysis revealed >99% homology between testicular and somatic cell mRNA, suggesting differential protein glycosylation. Dysadherin was immunodetected in round spermatids and testicular/ejaculated spermatozoa. It localizes to the acrosomal region and flagellum and colocalized with E-cadherin in the head and with the Na(+),K(+)-ATPase α4 subunit in the flagellum. This is the first report on expression of dysadherin in the male gonad and in spermatozoa. Its colocalization with E-cadherin and Na(+),K(+)-ATPase leads us to postulate a role for dysadherin as a modulator of sperm function.

Abstract 4310: Gene expression analysis of axial and appendicular osteosarcoma in the canine model

Abstract Spontaneously occurring canine osteosarcoma (OSA) is considered an excellent model of the human disease. Canine axial and appendicular osteosarcoma appear histopathologically identical. The clinical course of the two forms, however, seems to diverge. Following surgery, the axial form may be associated with a lower metastatic rate and longer survival than the appendicular form. Identifying gene expression profiles associated with decreased metastatic potential may be crucial for the development of targeted therapies for the human disease. We hypothesized that there are distinct gene expression patterns for canine axial and appendicular OSA. Six axial osteosarcoma tumor samples and six age, breed, and weight matched appendicular osteosarcoma clinical tumor samples were selected from the Center for Comparative Oncology, Michigan State University tissue bank. RNA extraction, amplification and labeling were performed using standard techniques. Raw gene expression values were obtained using the Affymetrix GeneChip Canine Genome 2.0 Array. Background correction, normalization, PM correction, summarization, and expression analysis were performed using the R software with the affy/limma/sva packages. Gene set enrichment analysis was performed using GSEA software. All RNA samples passed quality control and were included in the data set. The expression analysis took into account RNA degradation, which was similar in all tumor samples. A total of 184 genes were differentially expressed by &amp;gt;16-fold, between the two groups. Surrogate variable analysis did not result in any statistically significant differences in gene expression. Gene set enrichment analysis resulted in 9 gene sets enriched in axial, and 4 gene sets enriched in appendicular osteosarcoma samples at FDR &amp;lt; 25%. Gene ranking was similar between the two methods of analysis, with MMP1, ATP6AP1, SLC6A8, and dysadherin expression increased in axial tumor samples, while ICAM2 expression increased in appendicular samples. Expression analysis indicates no statistically significant differences in gene expression between the axial and appendicular OSA. Gene set enrichment analysis indicates potential differences in gene set enrichment between the two types of osteosarcoma. Further quantitative RT-PCR analysis is required to confirm our results. These data will guide hypothesis-driven translational studies, which may have direct clinical implications on the treatment of osteosarcoma. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4310. doi:10.1158/1538-7445.AM2011-4310

Osteoblast‐secreted factors enhance the expression of dysadherin and CCL2‐dependent migration of renal carcinoma cells

Renal cell carcinoma (RCC) frequently metastasizes to the bone marrow. These metastases are characterized by extensive osteolytic lesions. The mechanism, however, by which RCC cells metastasize to bone marrow remains poorly understood. To unravel the role of bone marrow cells in this context, we performed cell adhesion and migration assays using human RCC cell lines to analyze the influence of resident bone marrow cells on renal tumor cells. The strongest adhesion of RCC cells was observed to osteoblasts. Moreover, conditioned medium of osteoblasts (OB-CM) significantly increased RCC cell migration. By gene expression analysis dysadherin was identified as a transcript whose expression could be elevated more than twofold in RCC cells when exposed to OB-CM. Suppression of dysadherin expression in RCC cells by siRNA reduced their ability to migrate in the presence of OB-CM. Furthermore, the RCC cells secreted high amounts of the chemokine CCL2 when tumor cells migrated under the influence of osteoblast-secreted factors. CCL2 neutralization strongly reduced the migratory ability of the RCC cells. Silencing the expression of dysadherin in RCC cells resulted in a twofold reduction of CCL2 protein expression indicating a dysadherin-dependent expression of the chemokine. Taken together, our data show that osteoblasts are the major cell type of the bone marrow that affect RCC cells by secreting factors that increase the expression of dysadherin and CCL2 in the tumor cells leading to enhanced cell migration. These data suggest an osteoblast-induced autocrine mechanism for a facilitated homing of RCC cells to the bone marrow.

Significance of dysadherin and E-cadherin expression in differentiated-type gastric carcinoma with submucosal invasion

Dysadherin is a cancer-associated cell membrane glycoprotein that down-regulates E-cadherin and plays important roles in tumor progression and metastasis. Differentiated-type gastric carcinoma can be classified into 2 histologic subtypes according to the presence of poorly differentiated components: a mixed type (differentiated carcinoma with poorly differentiated components) and a pure type (purely differentiated-type adenocarcinoma). We studied the clinicopathologic features of 318 cases of differentiated-type gastric carcinoma with submucosal invasion and evaluated the immunohistochemical expression of dysadherin and E-cadherin. We also evaluated 46 cases of metastatic lymph nodes. Tumors with combined dysadherin-positive (≥50%) expression and E-cadherin-negative (<50%) expression had significantly higher proportions of the moderately differentiated type, deeper submucosal invasion, positivity of lymphatic permeation, and positivity of lymph node metastasis than tumors with other combinations of dysadherin and E-cadherin expression (P = .0009, P = .0015, P = .0273, and P = .0187, respectively). Moreover, the frequency of dysadherin-positive (≥50%) expression was higher in the mixed type (60.3%) than in the pure type (12.4%) (P < .0001), whereas the frequency of E-cadherin-negative (<50%) expression was higher in the mixed type (84.5%) than in the pure type (50.5%) (P < .0001). The frequency of dysadherin expression in the metastatic lymph nodes (80.4%) was significantly higher than that in the primary tumors (45.7%) (P = .001). Dysadherin-positive (≥50%) expression and E-cadherin-negative (<50%) expression may be correlated with the mixed type. Combined dysadherin-positive (≥50%) expression and E-cadherin-negative (<50%) expression may be valuable information for predicting aggressive tumor behavior.

Comparison of the dysadherin and E-cadherin expression in primary lung cancer and metastatic sites.

Dysadherin, a cancer associated cell membrane glycoprotein, has been reported to downregulate E-cadherin. Aberrant expression of E-cadherin has been associated with the development of metastases in patients with cancer. Even though the expression of dysadherin and E-cadherin has been studied in primary non-small cell lung carcinoma, little is known about its expression at the distant metastases sites. We investigate by immunohistochemistry the relationship between E-cadherin and dysadherin in 111 cases of primary lung carcinomas (53 squamous cell carcinomas, 21 adenocarcinomas, 13 large cell carcinomas, and 24 small cell carcinomas), and their distant metastases. The intensity, the expression pattern and the percentage of neoplastic cell staining were recorded and the results were correlated with clinicopathological findings of the subjects. Dysadherin immunostain was expressed in 61 (54.95%) of the cases, and increased dysadherin expression was significantly correlated with tumour size (p=0.003), distant metastases (p=0.0034), and metastasis size (p=0.0008). Reduced E-cadherin expression was noted in 46 (41.45%) of the cases, and was correlated with high-grade tumour (p=0.02), infiltrative growth pattern (p=0.042), and advanced stage (p=0.032). Although the correlation between the expression of dysadherin and E-cadherin was not significant, a group of patients showed reduced E-cadherin expression with dysadherin overexpression. In lung carcinomas dysadherin expression seems to reflect tumour aggressiveness and may be considered a positive marker of poor prognosis when considered alone or/and in combination with down-regulation of E-cadherin.

Dysadherin expression in gastrointestinal stromal tumors (GISTs)

The purpose of this study was to detect the protein and mRNA expression of dysadherin and to investigate the clinical significance of dysadherin expression in gastrointestinal stromal tumors (GISTs). Twenty fresh GISTs samples were used for testing the mRNA of dysadherin and E-cadherin by reverse-transcription polymerase chain reaction (RT-PCR). In addition, 54 paraffin blocks of GISTs cases were also used for the investigation of dysadherin and E-cadherin using immunohistochemistry. The dysadherin expression level was significantly correlated with GISTs risk stratification ( χ 2=5.769, P<0.05), but was not related to age, sex, histologic subtype, and location ( P>0.05). There was only faint or absent E-cadherin protein expression in GISTs. The expression level of dysadherin is related to the risk of GISTs. Dysadherin upregulation, which may cause loss of E-cadherin, is one of the reasons for GISTs recurrence and metastasis. It seems that dysadherin protein detection is a promising method for GISTs prognostication.

Differential Expression of Dysadherin in Papillary Thyroid Carcinoma and Microcarcinoma: Correlation with E-cadherin

Dysadherin is a novel glycoprotein, with an anti-cell-cell adhesion function. The aim of the present study was to examine the expression of dysadherin in thyroid papillary microcarcinoma (PMC), to associate it with the expression of E-cadherin and to investigate whether there are differences with papillary carcinoma (PC). A statistically significant difference in dysadherin and E-cadherin expression between PC and PMC and a negative correlation between E-cadherin and dysadherin expression regardless of tumor size were noted. Based on these findings it is hypothesized that retained cell-cell adhesion, through maintenance of the E-cadherin adhesion system, in PMC prevents neoplastic cells from dissociating easily from each other and metastasizing. Increased dysadherin expression is possibly one of the post-transcriptional mechanisms responsible for E-cadherin downregulation in thyroid papillary neoplasia.